Merge branch '8876' of https://code-repo.d4science.org/D-Net/dnet-hadoop into 8876

dhp-common/pom.xml

@@ -52,6 +52,8 @@
 					</execution>
 				</executions>
 				<configuration>
+					<failOnMultipleScalaVersions>true</failOnMultipleScalaVersions>
+					<scalaCompatVersion>${scala.binary.version}</scalaCompatVersion>
 					<scalaVersion>${scala.version}</scalaVersion>
 				</configuration>
 			</plugin>
@@ -60,6 +62,11 @@
 	</build>
 
 	<dependencies>
+		<dependency>
+			<groupId>eu.dnetlib.dhp</groupId>
+			<artifactId>dhp-pace-core</artifactId>
+			<version>${project.version}</version>
+		</dependency>
 
 		<dependency>
 			<groupId>org.apache.hadoop</groupId>
@@ -76,11 +83,11 @@
 
 		<dependency>
 			<groupId>org.apache.spark</groupId>
-			<artifactId>spark-core_2.11</artifactId>
+			<artifactId>spark-core_${scala.binary.version}</artifactId>
 		</dependency>
 		<dependency>
 			<groupId>org.apache.spark</groupId>
-			<artifactId>spark-sql_2.11</artifactId>
+			<artifactId>spark-sql_${scala.binary.version}</artifactId>
 		</dependency>
 
 		<dependency>
@@ -142,11 +149,6 @@
 			<artifactId>okhttp</artifactId>
 		</dependency>
 
-		<dependency>
-			<groupId>eu.dnetlib</groupId>
-			<artifactId>dnet-pace-core</artifactId>
-		</dependency>
-
 		<dependency>
 			<groupId>org.apache.httpcomponents</groupId>
 			<artifactId>httpclient</artifactId>
@@ -159,7 +161,7 @@
 
 		<dependency>
 			<groupId>eu.dnetlib.dhp</groupId>
-			<artifactId>dhp-schemas</artifactId>
+			<artifactId>${dhp-schemas.artifact}</artifactId>
 		</dependency>
 
 		<dependency>

dhp-common/src/main/java/eu/dnetlib/dhp/schema/oaf/utils/FundRefCleaningRule.java

@@ -6,14 +6,16 @@ import java.util.regex.Pattern;
 
 public class FundRefCleaningRule {
 
-	public static String clean(final String fundrefId) {
+	public static final Pattern PATTERN = Pattern.compile("\\d+");
 
-		String s = fundrefId
+	public static String clean(final String fundRefId) {
+
+		String s = fundRefId
 			.toLowerCase()
 			.replaceAll("\\s", "");
 
-		Matcher m = Pattern.compile("\\d+").matcher(s);
+		Matcher m = PATTERN.matcher(s);
-		if (m.matches()) {
+		if (m.find()) {
 			return m.group();
 		} else {
 			return "";

dhp-common/src/main/java/eu/dnetlib/dhp/schema/oaf/utils/GridCleaningRule.java

@@ -6,13 +6,19 @@ import java.util.regex.Pattern;
 
 public class GridCleaningRule {
 
+	public static final Pattern PATTERN = Pattern.compile("(?<grid>\\d{4,6}\\.[0-9a-z]{1,2})");
+
 	public static String clean(String grid) {
 		String s = grid
 			.replaceAll("\\s", "")
 			.toLowerCase();
 
-		Matcher m = Pattern.compile("\\d{4,6}\\.[0-9a-z]{1,2}").matcher(s);
+		Matcher m = PATTERN.matcher(s);
-		return m.matches() ? "grid." + m.group() : "";
+		if (m.find()) {
+			return "grid." + m.group("grid");
+		}
+
+		return "";
 	}
 
 }

dhp-common/src/main/java/eu/dnetlib/dhp/schema/oaf/utils/ISNICleaningRule.java

@@ -7,10 +7,12 @@ import java.util.regex.Pattern;
 // https://www.wikidata.org/wiki/Property:P213
 public class ISNICleaningRule {
 
+	public static final Pattern PATTERN = Pattern.compile("([0]{4}) ?([0-9]{4}) ?([0-9]{4}) ?([0-9]{3}[0-9X])");
+
 	public static String clean(final String isni) {
 
-		Matcher m = Pattern.compile("([0]{4}) ?([0-9]{4}) ?([0-9]{4}) ?([0-9]{3}[0-9X])").matcher(isni);
+		Matcher m = PATTERN.matcher(isni);
-		if (m.matches()) {
+		if (m.find()) {
 			return String.join("", m.group(1), m.group(2), m.group(3), m.group(4));
 		} else {
 			return "";

dhp-common/src/main/java/eu/dnetlib/dhp/schema/oaf/utils/PICCleaningRule.java

@@ -6,10 +6,12 @@ import java.util.regex.Pattern;
 
 public class PICCleaningRule {
 
+	public static final Pattern PATTERN = Pattern.compile("\\d{9}");
+
 	public static String clean(final String pic) {
 
-		Matcher m = Pattern.compile("\\d{9}").matcher(pic);
+		Matcher m = PATTERN.matcher(pic);
-		if (m.matches()) {
+		if (m.find()) {
 			return m.group();
 		} else {
 			return "";

dhp-common/src/main/java/eu/dnetlib/dhp/schema/oaf/utils/PmcCleaningRule.java

@@ -1,13 +1,24 @@
 
 package eu.dnetlib.dhp.schema.oaf.utils;
 
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
 public class PmcCleaningRule {
 
+	public static final Pattern PATTERN = Pattern.compile("PMC\\d{1,8}");
+
 	public static String clean(String pmc) {
 		String s = pmc
 			.replaceAll("\\s", "")
 			.toUpperCase();
-		return s.matches("^PMC\\d{1,8}$") ? s : "";
+
+		final Matcher m = PATTERN.matcher(s);
+
+		if (m.find()) {
+			return m.group();
+		}
+		return "";
 	}
 
 }

dhp-common/src/main/java/eu/dnetlib/dhp/schema/oaf/utils/PmidCleaningRule.java

@@ -1,16 +1,25 @@
 
 package eu.dnetlib.dhp.schema.oaf.utils;
 
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
 // https://researchguides.stevens.edu/c.php?g=442331&p=6577176
 public class PmidCleaningRule {
 
+	public static final Pattern PATTERN = Pattern.compile("[1-9]{1,8}");
+
 	public static String clean(String pmid) {
 		String s = pmid
 			.toLowerCase()
-			.replaceAll("\\s", "")
+			.replaceAll("\\s", "");
-			.trim()
+
-			.replaceAll("^0+", "");
+		final Matcher m = PATTERN.matcher(s);
-		return s.matches("^\\d{1,8}$") ? s : "";
+
+		if (m.find()) {
+			return m.group();
+		}
+		return "";
 	}
 
 }

dhp-common/src/main/java/eu/dnetlib/dhp/schema/oaf/utils/RorCleaningRule.java

@@ -7,12 +7,21 @@ import java.util.regex.Pattern;
 // https://ror.readme.io/docs/ror-identifier-pattern
 public class RorCleaningRule {
 
+	public static final String ROR_PREFIX = "https://ror.org/";
+
+	private static final Pattern PATTERN = Pattern.compile("(?<ror>0[a-hj-km-np-tv-z|0-9]{6}[0-9]{2})");
+
 	public static String clean(String ror) {
 		String s = ror
 			.replaceAll("\\s", "")
 			.toLowerCase();
-		Matcher m = Pattern.compile("0[a-hj-km-np-tv-z|0-9]{6}[0-9]{2}").matcher(s);
+
-		return m.matches() ? "https://ror.org/" + m.group() : "";
+		Matcher m = PATTERN.matcher(s);
+
+		if (m.find()) {
+			return ROR_PREFIX + m.group("ror");
+		}
+		return "";
 	}
 
 }

dhp-common/src/test/java/eu/dnetlib/dhp/common/MdStoreClientTest.java

@@ -15,7 +15,7 @@ import com.fasterxml.jackson.databind.ObjectMapper;
 
 public class MdStoreClientTest {
 
-	@Test
+	// @Test
 	public void testMongoCollection() throws IOException {
 		final MdstoreClient client = new MdstoreClient("mongodb://localhost:27017", "mdstore");
 

dhp-common/src/test/java/eu/dnetlib/dhp/schema/oaf/utils/GridCleaningRuleTest.java

@@ -0,0 +1,18 @@
+
+package eu.dnetlib.dhp.schema.oaf.utils;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.Test;
+
+class GridCleaningRuleTest {
+
+	@Test
+	void testCleaning() {
+		assertEquals("grid.493784.5", GridCleaningRule.clean("grid.493784.5"));
+		assertEquals("grid.493784.5x", GridCleaningRule.clean("grid.493784.5x"));
+		assertEquals("grid.493784.5x", GridCleaningRule.clean("493784.5x"));
+		assertEquals("", GridCleaningRule.clean("493x784.5x"));
+	}
+
+}

dhp-common/src/test/java/eu/dnetlib/dhp/schema/oaf/utils/ISNICleaningRuleTest.java

@@ -0,0 +1,19 @@
+
+package eu.dnetlib.dhp.schema.oaf.utils;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.Test;
+
+class ISNICleaningRuleTest {
+
+	@Test
+	void testCleaning() {
+		assertEquals("0000000463436020", ISNICleaningRule.clean("0000 0004 6343 6020"));
+		assertEquals("0000000463436020", ISNICleaningRule.clean("0000000463436020"));
+		assertEquals("", ISNICleaningRule.clean("Q30256598"));
+		assertEquals("0000000493403529", ISNICleaningRule.clean("ISNI:0000000493403529"));
+		assertEquals("000000008614884X", ISNICleaningRule.clean("0000 0000 8614 884X"));
+	}
+
+}

dhp-common/src/test/java/eu/dnetlib/dhp/schema/oaf/utils/PICCleaningRuleTest.java

@@ -0,0 +1,19 @@
+
+package eu.dnetlib.dhp.schema.oaf.utils;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.Test;
+
+class PICCleaningRuleTest {
+
+	@Test
+	void testCleaning() {
+		assertEquals("887624982", PICCleaningRule.clean("887624982"));
+		assertEquals("", PICCleaningRule.clean("887 624982"));
+		assertEquals("887624982", PICCleaningRule.clean(" 887624982 "));
+		assertEquals("887624982", PICCleaningRule.clean(" 887624982x "));
+		assertEquals("887624982", PICCleaningRule.clean(" 88762498200 "));
+	}
+
+}

dhp-common/src/test/java/eu/dnetlib/dhp/schema/oaf/utils/PmcCleaningRuleTest.java

@@ -0,0 +1,19 @@
+
+package eu.dnetlib.dhp.schema.oaf.utils;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.Test;
+
+class PmcCleaningRuleTest {
+
+	@Test
+	void testCleaning() {
+		assertEquals("PMC1234", PmcCleaningRule.clean("PMC1234"));
+		assertEquals("PMC1234", PmcCleaningRule.clean(" PMC1234"));
+		assertEquals("PMC12345678", PmcCleaningRule.clean("PMC12345678"));
+		assertEquals("PMC12345678", PmcCleaningRule.clean("PMC123456789"));
+		assertEquals("PMC12345678", PmcCleaningRule.clean("PMC 12345678"));
+	}
+
+}

dhp-common/src/test/java/eu/dnetlib/dhp/schema/oaf/utils/PmidCleaningRuleTest.java

@@ -0,0 +1,18 @@
+
+package eu.dnetlib.dhp.schema.oaf.utils;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.Test;
+
+class PmidCleaningRuleTest {
+
+	@Test
+	void testCleaning() {
+		assertEquals("1234", PmidCleaningRule.clean("01234"));
+		assertEquals("1234567", PmidCleaningRule.clean("0123 4567"));
+		assertEquals("123", PmidCleaningRule.clean("0123x4567"));
+		assertEquals("", PmidCleaningRule.clean("abc"));
+	}
+
+}

dhp-common/src/test/java/eu/dnetlib/dhp/schema/oaf/utils/RorCleaningRuleTest.java

@@ -0,0 +1,17 @@
+
+package eu.dnetlib.dhp.schema.oaf.utils;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.Test;
+
+class RorCleaningRuleTest {
+
+	@Test
+	void testCleaning() {
+		assertEquals("https://ror.org/05rpz9w55", RorCleaningRule.clean("https://ror.org/05rpz9w55"));
+		assertEquals("https://ror.org/05rpz9w55", RorCleaningRule.clean("05rpz9w55"));
+		assertEquals("", RorCleaningRule.clean("05rpz9w_55"));
+	}
+
+}

dhp-pace-core/pom.xml

@@ -0,0 +1,110 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+
+    <modelVersion>4.0.0</modelVersion>
+
+	<parent>
+		<groupId>eu.dnetlib.dhp</groupId>
+		<artifactId>dhp</artifactId>
+		<version>1.2.5-SNAPSHOT</version>
+        <relativePath>../pom.xml</relativePath>
+	</parent>
+
+	<groupId>eu.dnetlib.dhp</groupId>
+	<artifactId>dhp-pace-core</artifactId>
+	<version>1.2.5-SNAPSHOT</version>
+    <packaging>jar</packaging>
+
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>net.alchim31.maven</groupId>
+				<artifactId>scala-maven-plugin</artifactId>
+				<version>${net.alchim31.maven.version}</version>
+				<executions>
+					<execution>
+						<id>scala-compile-first</id>
+						<phase>initialize</phase>
+						<goals>
+							<goal>add-source</goal>
+							<goal>compile</goal>
+						</goals>
+					</execution>
+					<execution>
+						<id>scala-test-compile</id>
+						<phase>process-test-resources</phase>
+						<goals>
+							<goal>testCompile</goal>
+						</goals>
+					</execution>
+				</executions>
+				<configuration>
+					<failOnMultipleScalaVersions>true</failOnMultipleScalaVersions>
+					<scalaCompatVersion>${scala.binary.version}</scalaCompatVersion>
+					<scalaVersion>${scala.version}</scalaVersion>
+				</configuration>
+			</plugin>
+		</plugins>
+
+	</build>
+
+	<dependencies>
+		<dependency>
+			<groupId>edu.cmu</groupId>
+			<artifactId>secondstring</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>com.google.guava</groupId>
+			<artifactId>guava</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>com.google.code.gson</groupId>
+			<artifactId>gson</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.apache.commons</groupId>
+			<artifactId>commons-lang3</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>commons-io</groupId>
+			<artifactId>commons-io</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.antlr</groupId>
+			<artifactId>stringtemplate</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>commons-logging</groupId>
+			<artifactId>commons-logging</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.reflections</groupId>
+			<artifactId>reflections</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>com.fasterxml.jackson.core</groupId>
+			<artifactId>jackson-databind</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.apache.commons</groupId>
+			<artifactId>commons-math3</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>com.jayway.jsonpath</groupId>
+			<artifactId>json-path</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>com.ibm.icu</groupId>
+			<artifactId>icu4j</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.apache.spark</groupId>
+			<artifactId>spark-core_${scala.binary.version}</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.apache.spark</groupId>
+			<artifactId>spark-sql_${scala.binary.version}</artifactId>
+		</dependency>
+	</dependencies>
+
+</project>

dhp-pace-core/src/main/java/eu/dnetlib/pace/clustering/AbstractClusteringFunction.java

@@ -0,0 +1,46 @@
+
+package eu.dnetlib.pace.clustering;
+
+import java.util.Collection;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+import org.apache.commons.lang3.StringUtils;
+
+import eu.dnetlib.pace.common.AbstractPaceFunctions;
+import eu.dnetlib.pace.config.Config;
+
+public abstract class AbstractClusteringFunction extends AbstractPaceFunctions implements ClusteringFunction {
+
+	protected Map<String, Integer> params;
+
+	public AbstractClusteringFunction(final Map<String, Integer> params) {
+		this.params = params;
+	}
+
+	protected abstract Collection<String> doApply(Config conf, String s);
+
+	@Override
+	public Collection<String> apply(Config conf, List<String> fields) {
+		return fields
+			.stream()
+			.filter(f -> !f.isEmpty())
+			.map(this::normalize)
+			.map(s -> filterAllStopWords(s))
+			.map(s -> doApply(conf, s))
+			.map(c -> filterBlacklisted(c, ngramBlacklist))
+			.flatMap(c -> c.stream())
+			.filter(StringUtils::isNotBlank)
+			.collect(Collectors.toCollection(HashSet::new));
+	}
+
+	public Map<String, Integer> getParams() {
+		return params;
+	}
+
+	protected Integer param(String name) {
+		return params.get(name);
+	}
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/clustering/Acronyms.java

@@ -0,0 +1,51 @@
+
+package eu.dnetlib.pace.clustering;
+
+import java.util.Collection;
+import java.util.Map;
+import java.util.Set;
+import java.util.StringTokenizer;
+
+import com.google.common.collect.Sets;
+
+import eu.dnetlib.pace.config.Config;
+
+@ClusteringClass("acronyms")
+public class Acronyms extends AbstractClusteringFunction {
+
+	public Acronyms(Map<String, Integer> params) {
+		super(params);
+	}
+
+	@Override
+	protected Collection<String> doApply(Config conf, String s) {
+		return extractAcronyms(s, param("max"), param("minLen"), param("maxLen"));
+	}
+
+	private Set<String> extractAcronyms(final String s, int maxAcronyms, int minLen, int maxLen) {
+
+		final Set<String> acronyms = Sets.newLinkedHashSet();
+
+		for (int i = 0; i < maxAcronyms; i++) {
+
+			final StringTokenizer st = new StringTokenizer(s);
+			final StringBuilder sb = new StringBuilder();
+
+			while (st.hasMoreTokens()) {
+				final String token = st.nextToken();
+				if (sb.length() > maxLen) {
+					break;
+				}
+				if (token.length() > 1 && i < token.length()) {
+					sb.append(token.charAt(i));
+				}
+			}
+			String acronym = sb.toString();
+			if (acronym.length() > minLen) {
+				acronyms.add(acronym);
+			}
+		}
+		return acronyms;
+	}
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/clustering/ClusteringClass.java

@@ -0,0 +1,14 @@
+
+package eu.dnetlib.pace.clustering;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.TYPE)
+public @interface ClusteringClass {
+
+	public String value();
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/clustering/ClusteringFunction.java

@@ -0,0 +1,16 @@
+
+package eu.dnetlib.pace.clustering;
+
+import java.util.Collection;
+import java.util.List;
+import java.util.Map;
+
+import eu.dnetlib.pace.config.Config;
+
+public interface ClusteringFunction {
+
+	public Collection<String> apply(Config config, List<String> fields);
+
+	public Map<String, Integer> getParams();
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/clustering/ImmutableFieldValue.java

@@ -0,0 +1,28 @@
+
+package eu.dnetlib.pace.clustering;
+
+import java.util.Collection;
+import java.util.List;
+import java.util.Map;
+
+import com.google.common.collect.Lists;
+
+import eu.dnetlib.pace.config.Config;
+
+@ClusteringClass("immutablefieldvalue")
+public class ImmutableFieldValue extends AbstractClusteringFunction {
+
+	public ImmutableFieldValue(final Map<String, Integer> params) {
+		super(params);
+	}
+
+	@Override
+	protected Collection<String> doApply(final Config conf, final String s) {
+		final List<String> res = Lists.newArrayList();
+
+		res.add(s);
+
+		return res;
+	}
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/clustering/KeywordsClustering.java

@@ -0,0 +1,54 @@
+
+package eu.dnetlib.pace.clustering;
+
+import java.util.*;
+import java.util.stream.Collectors;
+
+import org.apache.commons.lang3.StringUtils;
+
+import eu.dnetlib.pace.config.Config;
+
+@ClusteringClass("keywordsclustering")
+public class KeywordsClustering extends AbstractClusteringFunction {
+
+	public KeywordsClustering(Map<String, Integer> params) {
+		super(params);
+	}
+
+	@Override
+	protected Collection<String> doApply(final Config conf, String s) {
+
+		// takes city codes and keywords codes without duplicates
+		Set<String> keywords = getKeywords(s, conf.translationMap(), params.getOrDefault("windowSize", 4));
+		Set<String> cities = getCities(s, params.getOrDefault("windowSize", 4));
+
+		// list of combination to return as result
+		final Collection<String> combinations = new LinkedHashSet<String>();
+
+		for (String keyword : keywordsToCodes(keywords, conf.translationMap())) {
+			for (String city : citiesToCodes(cities)) {
+				combinations.add(keyword + "-" + city);
+				if (combinations.size() >= params.getOrDefault("max", 2)) {
+					return combinations;
+				}
+			}
+		}
+
+		return combinations;
+	}
+
+	@Override
+	public Collection<String> apply(final Config conf, List<String> fields) {
+		return fields
+			.stream()
+			.filter(f -> !f.isEmpty())
+			.map(this::cleanup)
+			.map(this::normalize)
+			.map(s -> filterAllStopWords(s))
+			.map(s -> doApply(conf, s))
+			.map(c -> filterBlacklisted(c, ngramBlacklist))
+			.flatMap(c -> c.stream())
+			.filter(StringUtils::isNotBlank)
+			.collect(Collectors.toCollection(HashSet::new));
+	}
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/clustering/LastNameFirstInitial.java

@@ -0,0 +1,79 @@
+
+package eu.dnetlib.pace.clustering;
+
+import java.util.*;
+import java.util.stream.Collectors;
+
+import org.apache.commons.lang3.StringUtils;
+
+import com.google.common.collect.Lists;
+
+import eu.dnetlib.pace.config.Config;
+import eu.dnetlib.pace.model.Person;
+
+@ClusteringClass("lnfi")
+public class LastNameFirstInitial extends AbstractClusteringFunction {
+
+	private boolean DEFAULT_AGGRESSIVE = true;
+
+	public LastNameFirstInitial(final Map<String, Integer> params) {
+		super(params);
+	}
+
+	@Override
+	public Collection<String> apply(Config conf, List<String> fields) {
+		return fields
+			.stream()
+			.filter(f -> !f.isEmpty())
+			.map(this::normalize)
+			.map(s -> doApply(conf, s))
+			.map(c -> filterBlacklisted(c, ngramBlacklist))
+			.flatMap(c -> c.stream())
+			.filter(StringUtils::isNotBlank)
+			.collect(Collectors.toCollection(HashSet::new));
+	}
+
+	@Override
+	protected String normalize(final String s) {
+		return fixAliases(transliterate(nfd(unicodeNormalization(s))))
+			// do not compact the regexes in a single expression, would cause StackOverflowError in case of large input
+			// strings
+			.replaceAll("[^ \\w]+", "")
+			.replaceAll("(\\p{InCombiningDiacriticalMarks})+", "")
+			.replaceAll("(\\p{Punct})+", " ")
+			.replaceAll("(\\d)+", " ")
+			.replaceAll("(\\n)+", " ")
+			.trim();
+	}
+
+	@Override
+	protected Collection<String> doApply(final Config conf, final String s) {
+
+		final List<String> res = Lists.newArrayList();
+
+		final boolean aggressive = (Boolean) (getParams().containsKey("aggressive") ? getParams().get("aggressive")
+			: DEFAULT_AGGRESSIVE);
+
+		Person p = new Person(s, aggressive);
+
+		if (p.isAccurate()) {
+			String lastName = p.getNormalisedSurname().toLowerCase();
+			String firstInitial = p.getNormalisedFirstName().toLowerCase().substring(0, 1);
+
+			res.add(firstInitial.concat(lastName));
+		} else { // is not accurate, meaning it has no defined name and surname
+			List<String> fullname = Arrays.asList(p.getNormalisedFullname().split(" "));
+			if (fullname.size() == 1) {
+				res.add(p.getNormalisedFullname().toLowerCase());
+			} else if (fullname.size() == 2) {
+				res.add(fullname.get(0).substring(0, 1).concat(fullname.get(1)).toLowerCase());
+				res.add(fullname.get(1).substring(0, 1).concat(fullname.get(0)).toLowerCase());
+			} else {
+				res.add(fullname.get(0).substring(0, 1).concat(fullname.get(fullname.size() - 1)).toLowerCase());
+				res.add(fullname.get(fullname.size() - 1).substring(0, 1).concat(fullname.get(0)).toLowerCase());
+			}
+		}
+
+		return res;
+	}
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/clustering/LowercaseClustering.java

@@ -0,0 +1,38 @@
+
+package eu.dnetlib.pace.clustering;
+
+import java.util.Collection;
+import java.util.List;
+import java.util.Map;
+
+import org.apache.commons.lang3.StringUtils;
+
+import com.google.common.collect.Lists;
+import com.google.common.collect.Sets;
+
+import eu.dnetlib.pace.config.Config;
+
+@ClusteringClass("lowercase")
+public class LowercaseClustering extends AbstractClusteringFunction {
+
+	public LowercaseClustering(final Map<String, Integer> params) {
+		super(params);
+	}
+
+	@Override
+	public Collection<String> apply(Config conf, List<String> fields) {
+		Collection<String> c = Sets.newLinkedHashSet();
+		for (String f : fields) {
+			c.addAll(doApply(conf, f));
+		}
+		return c;
+	}
+
+	@Override
+	protected Collection<String> doApply(final Config conf, final String s) {
+		if (StringUtils.isBlank(s)) {
+			return Lists.newArrayList();
+		}
+		return Lists.newArrayList(s.toLowerCase().trim());
+	}
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/clustering/NGramUtils.java

@@ -0,0 +1,24 @@
+
+package eu.dnetlib.pace.clustering;
+
+import java.util.Set;
+
+import org.apache.commons.lang3.StringUtils;
+
+import eu.dnetlib.pace.common.AbstractPaceFunctions;
+
+public class NGramUtils extends AbstractPaceFunctions {
+	static private final NGramUtils NGRAMUTILS = new NGramUtils();
+
+	private static final int SIZE = 100;
+
+	private static final Set<String> stopwords = AbstractPaceFunctions
+		.loadFromClasspath("/eu/dnetlib/pace/config/stopwords_en.txt");
+
+	public static String cleanupForOrdering(String s) {
+		return (NGRAMUTILS.filterStopWords(NGRAMUTILS.normalize(s), stopwords) + StringUtils.repeat(" ", SIZE))
+			.substring(0, SIZE)
+			.replaceAll(" ", "");
+	}
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/clustering/NgramPairs.java

@@ -0,0 +1,41 @@
+
+package eu.dnetlib.pace.clustering;
+
+import java.util.Collection;
+import java.util.List;
+import java.util.Map;
+
+import com.google.common.collect.Lists;
+
+import eu.dnetlib.pace.config.Config;
+
+@ClusteringClass("ngrampairs")
+public class NgramPairs extends Ngrams {
+
+	public NgramPairs(Map<String, Integer> params) {
+		super(params, false);
+	}
+
+	public NgramPairs(Map<String, Integer> params, boolean sorted) {
+		super(params, sorted);
+	}
+
+	@Override
+	protected Collection<String> doApply(Config conf, String s) {
+		return ngramPairs(Lists.newArrayList(getNgrams(s, param("ngramLen"), param("max") * 2, 1, 2)), param("max"));
+	}
+
+	protected Collection<String> ngramPairs(final List<String> ngrams, int maxNgrams) {
+		Collection<String> res = Lists.newArrayList();
+		int j = 0;
+		for (int i = 0; i < ngrams.size() && res.size() < maxNgrams; i++) {
+			if (++j >= ngrams.size()) {
+				break;
+			}
+			res.add(ngrams.get(i) + ngrams.get(j));
+			// System.out.println("-- " + concatNgrams);
+		}
+		return res;
+	}
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/clustering/Ngrams.java

@@ -0,0 +1,52 @@
+
+package eu.dnetlib.pace.clustering;
+
+import java.util.*;
+
+import eu.dnetlib.pace.config.Config;
+
+@ClusteringClass("ngrams")
+public class Ngrams extends AbstractClusteringFunction {
+
+	private final boolean sorted;
+
+	public Ngrams(Map<String, Integer> params) {
+		this(params, false);
+	}
+
+	public Ngrams(Map<String, Integer> params, boolean sorted) {
+		super(params);
+		this.sorted = sorted;
+	}
+
+	@Override
+	protected Collection<String> doApply(Config conf, String s) {
+		return getNgrams(s, param("ngramLen"), param("max"), param("maxPerToken"), param("minNgramLen"));
+	}
+
+	protected Collection<String> getNgrams(String s, int ngramLen, int max, int maxPerToken, int minNgramLen) {
+
+		final Collection<String> ngrams = sorted ? new TreeSet<>() : new LinkedHashSet<String>();
+		final StringTokenizer st = new StringTokenizer(s);
+
+		while (st.hasMoreTokens()) {
+			final String token = st.nextToken();
+			if (!token.isEmpty()) {
+				for (int i = 0; i < maxPerToken && ngramLen + i <= token.length(); i++) {
+					String ngram = token.substring(i, Math.min(ngramLen + i, token.length())).trim();
+
+					if (ngram.length() >= minNgramLen) {
+						ngrams.add(ngram);
+
+						if (ngrams.size() >= max) {
+							return ngrams;
+						}
+					}
+				}
+			}
+		}
+		// System.out.println(ngrams + " n: " + ngrams.size());
+		return ngrams;
+	}
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/clustering/PersonClustering.java

@@ -0,0 +1,84 @@
+
+package eu.dnetlib.pace.clustering;
+
+import java.util.Collection;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+import org.apache.commons.lang3.StringUtils;
+
+import com.google.common.collect.Sets;
+
+import eu.dnetlib.pace.common.AbstractPaceFunctions;
+import eu.dnetlib.pace.config.Config;
+import eu.dnetlib.pace.model.Person;
+
+@ClusteringClass("personClustering")
+public class PersonClustering extends AbstractPaceFunctions implements ClusteringFunction {
+
+	private Map<String, Integer> params;
+
+	private static final int MAX_TOKENS = 5;
+
+	public PersonClustering(final Map<String, Integer> params) {
+		this.params = params;
+	}
+
+	@Override
+	public Collection<String> apply(final Config conf, final List<String> fields) {
+		final Set<String> hashes = Sets.newHashSet();
+
+		for (final String f : fields) {
+
+			final Person person = new Person(f, false);
+
+			if (StringUtils.isNotBlank(person.getNormalisedFirstName())
+				&& StringUtils.isNotBlank(person.getNormalisedSurname())) {
+				hashes.add(firstLC(person.getNormalisedFirstName()) + person.getNormalisedSurname().toLowerCase());
+			} else {
+				for (final String token1 : tokens(f, MAX_TOKENS)) {
+					for (final String token2 : tokens(f, MAX_TOKENS)) {
+						if (!token1.equals(token2)) {
+							hashes.add(firstLC(token1) + token2);
+						}
+					}
+				}
+			}
+		}
+
+		return hashes;
+	}
+
+//	@Override
+//	public Collection<String> apply(final List<Field> fields) {
+//		final Set<String> hashes = Sets.newHashSet();
+//
+//		for (final Field f : fields) {
+//
+//			final GTAuthor gta = GTAuthor.fromOafJson(f.stringValue());
+//
+//			final Author a = gta.getAuthor();
+//
+//			if (StringUtils.isNotBlank(a.getFirstname()) && StringUtils.isNotBlank(a.getSecondnames())) {
+//				hashes.add(firstLC(a.getFirstname()) + a.getSecondnames().toLowerCase());
+//			} else {
+//				for (final String token1 : tokens(f.stringValue(), MAX_TOKENS)) {
+//					for (final String token2 : tokens(f.stringValue(), MAX_TOKENS)) {
+//						if (!token1.equals(token2)) {
+//							hashes.add(firstLC(token1) + token2);
+//						}
+//					}
+//				}
+//			}
+//		}
+//
+//		return hashes;
+//	}
+
+	@Override
+	public Map<String, Integer> getParams() {
+		return params;
+	}
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/clustering/PersonHash.java

@@ -0,0 +1,34 @@
+
+package eu.dnetlib.pace.clustering;
+
+import java.util.Collection;
+import java.util.List;
+import java.util.Map;
+
+import com.google.common.collect.Lists;
+
+import eu.dnetlib.pace.config.Config;
+import eu.dnetlib.pace.model.Person;
+
+@ClusteringClass("personHash")
+public class PersonHash extends AbstractClusteringFunction {
+
+	private boolean DEFAULT_AGGRESSIVE = false;
+
+	public PersonHash(final Map<String, Integer> params) {
+		super(params);
+	}
+
+	@Override
+	protected Collection<String> doApply(final Config conf, final String s) {
+		final List<String> res = Lists.newArrayList();
+
+		final boolean aggressive = (Boolean) (getParams().containsKey("aggressive") ? getParams().get("aggressive")
+			: DEFAULT_AGGRESSIVE);
+
+		res.add(new Person(s, aggressive).hash());
+
+		return res;
+	}
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/clustering/RandomClusteringFunction.java

@@ -0,0 +1,20 @@
+
+package eu.dnetlib.pace.clustering;
+
+import java.util.Collection;
+import java.util.Map;
+
+import eu.dnetlib.pace.config.Config;
+
+public class RandomClusteringFunction extends AbstractClusteringFunction {
+
+	public RandomClusteringFunction(Map<String, Integer> params) {
+		super(params);
+	}
+
+	@Override
+	protected Collection<String> doApply(final Config conf, String s) {
+		return null;
+	}
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/clustering/SortedNgramPairs.java

@@ -0,0 +1,31 @@
+
+package eu.dnetlib.pace.clustering;
+
+import java.util.*;
+
+import com.google.common.base.Joiner;
+import com.google.common.base.Splitter;
+import com.google.common.collect.Lists;
+
+import eu.dnetlib.pace.config.Config;
+
+@ClusteringClass("sortedngrampairs")
+public class SortedNgramPairs extends NgramPairs {
+
+	public SortedNgramPairs(Map<String, Integer> params) {
+		super(params, false);
+	}
+
+	@Override
+	protected Collection<String> doApply(Config conf, String s) {
+
+		final List<String> tokens = Lists.newArrayList(Splitter.on(" ").omitEmptyStrings().trimResults().split(s));
+
+		Collections.sort(tokens);
+
+		return ngramPairs(
+			Lists.newArrayList(getNgrams(Joiner.on(" ").join(tokens), param("ngramLen"), param("max") * 2, 1, 2)),
+			param("max"));
+	}
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/clustering/SpaceTrimmingFieldValue.java

@@ -0,0 +1,34 @@
+
+package eu.dnetlib.pace.clustering;
+
+import java.util.Collection;
+import java.util.List;
+import java.util.Map;
+
+import org.apache.commons.lang3.RandomStringUtils;
+import org.apache.commons.lang3.StringUtils;
+
+import com.google.common.collect.Lists;
+
+import eu.dnetlib.pace.config.Config;
+
+@ClusteringClass("spacetrimmingfieldvalue")
+public class SpaceTrimmingFieldValue extends AbstractClusteringFunction {
+
+	public SpaceTrimmingFieldValue(final Map<String, Integer> params) {
+		super(params);
+	}
+
+	@Override
+	protected Collection<String> doApply(final Config conf, final String s) {
+		final List<String> res = Lists.newArrayList();
+
+		res
+			.add(
+				StringUtils.isBlank(s) ? RandomStringUtils.random(getParams().get("randomLength"))
+					: s.toLowerCase().replaceAll("\\s+", ""));
+
+		return res;
+	}
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/clustering/SuffixPrefix.java

@@ -0,0 +1,42 @@
+
+package eu.dnetlib.pace.clustering;
+
+import java.util.Collection;
+import java.util.Map;
+import java.util.Set;
+
+import com.google.common.collect.Sets;
+
+import eu.dnetlib.pace.config.Config;
+
+@ClusteringClass("suffixprefix")
+public class SuffixPrefix extends AbstractClusteringFunction {
+
+	public SuffixPrefix(Map<String, Integer> params) {
+		super(params);
+	}
+
+	@Override
+	protected Collection<String> doApply(Config conf, String s) {
+		return suffixPrefix(s, param("len"), param("max"));
+	}
+
+	private Collection<String> suffixPrefix(String s, int len, int max) {
+		final Set<String> bigrams = Sets.newLinkedHashSet();
+		int i = 0;
+		while (++i < s.length() && bigrams.size() < max) {
+			int j = s.indexOf(" ", i);
+
+			int offset = j + len + 1 < s.length() ? j + len + 1 : s.length();
+
+			if (j - len > 0) {
+				String bigram = s.substring(j - len, offset).replaceAll(" ", "").trim();
+				if (bigram.length() >= 4) {
+					bigrams.add(bigram);
+				}
+			}
+		}
+		return bigrams;
+	}
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/clustering/UrlClustering.java

@@ -0,0 +1,52 @@
+
+package eu.dnetlib.pace.clustering;
+
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.util.Collection;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+import eu.dnetlib.pace.common.AbstractPaceFunctions;
+import eu.dnetlib.pace.config.Config;
+
+@ClusteringClass("urlclustering")
+public class UrlClustering extends AbstractPaceFunctions implements ClusteringFunction {
+
+	protected Map<String, Integer> params;
+
+	public UrlClustering(final Map<String, Integer> params) {
+		this.params = params;
+	}
+
+	@Override
+	public Collection<String> apply(final Config conf, List<String> fields) {
+		try {
+			return fields
+				.stream()
+				.filter(f -> !f.isEmpty())
+				.map(this::asUrl)
+				.map(URL::getHost)
+				.collect(Collectors.toCollection(HashSet::new));
+		} catch (IllegalStateException e) {
+			return new HashSet<>();
+		}
+	}
+
+	@Override
+	public Map<String, Integer> getParams() {
+		return null;
+	}
+
+	private URL asUrl(String value) {
+		try {
+			return new URL(value);
+		} catch (MalformedURLException e) {
+			// should not happen as checked by pace typing
+			throw new IllegalStateException("invalid URL: " + value);
+		}
+	}
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/clustering/WordsStatsSuffixPrefixChain.java

@@ -0,0 +1,91 @@
+
+package eu.dnetlib.pace.clustering;
+
+import java.util.*;
+import java.util.stream.Collectors;
+
+import com.google.common.collect.Sets;
+
+import eu.dnetlib.pace.config.Config;
+
+@ClusteringClass("wordsStatsSuffixPrefixChain")
+public class WordsStatsSuffixPrefixChain extends AbstractClusteringFunction {
+
+	public WordsStatsSuffixPrefixChain(Map<String, Integer> params) {
+		super(params);
+	}
+
+	@Override
+	protected Collection<String> doApply(Config conf, String s) {
+		return suffixPrefixChain(s, param("mod"));
+	}
+
+	private Collection<String> suffixPrefixChain(String s, int mod) {
+
+		// create the list of words from the string (remove short words)
+		List<String> wordsList = Arrays
+			.stream(s.split(" "))
+			.filter(si -> si.length() > 3)
+			.collect(Collectors.toList());
+
+		final int words = wordsList.size();
+		final int letters = s.length();
+
+		// create the prefix: number of words + number of letters/mod
+		String prefix = words + "-" + letters / mod + "-";
+
+		return doSuffixPrefixChain(wordsList, prefix);
+
+	}
+
+	private Collection<String> doSuffixPrefixChain(List<String> wordsList, String prefix) {
+
+		Set<String> set = Sets.newLinkedHashSet();
+		switch (wordsList.size()) {
+			case 0:
+			case 1:
+				break;
+			case 2:
+				set
+					.add(
+						prefix +
+							suffix(wordsList.get(0), 3) +
+							prefix(wordsList.get(1), 3));
+
+				set
+					.add(
+						prefix +
+							prefix(wordsList.get(0), 3) +
+							suffix(wordsList.get(1), 3));
+
+				break;
+			default:
+				set
+					.add(
+						prefix +
+							suffix(wordsList.get(0), 3) +
+							prefix(wordsList.get(1), 3) +
+							suffix(wordsList.get(2), 3));
+
+				set
+					.add(
+						prefix +
+							prefix(wordsList.get(0), 3) +
+							suffix(wordsList.get(1), 3) +
+							prefix(wordsList.get(2), 3));
+				break;
+		}
+
+		return set;
+
+	}
+
+	private String suffix(String s, int len) {
+		return s.substring(s.length() - len);
+	}
+
+	private String prefix(String s, int len) {
+		return s.substring(0, len);
+	}
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/clustering/WordsSuffixPrefix.java

@@ -0,0 +1,59 @@
+
+package eu.dnetlib.pace.clustering;
+
+import java.util.Collection;
+import java.util.Map;
+import java.util.Set;
+
+import com.google.common.collect.Sets;
+
+import eu.dnetlib.pace.config.Config;
+
+@ClusteringClass("wordssuffixprefix")
+public class WordsSuffixPrefix extends AbstractClusteringFunction {
+
+	public WordsSuffixPrefix(Map<String, Integer> params) {
+		super(params);
+	}
+
+	@Override
+	protected Collection<String> doApply(Config conf, String s) {
+		return suffixPrefix(s, param("len"), param("max"));
+	}
+
+	private Collection<String> suffixPrefix(String s, int len, int max) {
+
+		final int words = s.split(" ").length;
+
+		// adjust the token length according to the number of words
+		switch (words) {
+			case 1:
+				return Sets.newLinkedHashSet();
+			case 2:
+				return doSuffixPrefix(s, len + 2, max, words);
+			case 3:
+				return doSuffixPrefix(s, len + 1, max, words);
+			default:
+				return doSuffixPrefix(s, len, max, words);
+		}
+	}
+
+	private Collection<String> doSuffixPrefix(String s, int len, int max, int words) {
+		final Set<String> bigrams = Sets.newLinkedHashSet();
+		int i = 0;
+		while (++i < s.length() && bigrams.size() < max) {
+			int j = s.indexOf(" ", i);
+
+			int offset = j + len + 1 < s.length() ? j + len + 1 : s.length();
+
+			if (j - len > 0) {
+				String bigram = s.substring(j - len, offset).replaceAll(" ", "").trim();
+				if (bigram.length() >= 4) {
+					bigrams.add(words + bigram);
+				}
+			}
+		}
+		return bigrams;
+	}
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/common/AbstractPaceFunctions.java

@@ -0,0 +1,357 @@
+
+package eu.dnetlib.pace.common;
+
+import java.io.IOException;
+import java.io.StringWriter;
+import java.nio.charset.StandardCharsets;
+import java.text.Normalizer;
+import java.util.*;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+import java.util.stream.Collectors;
+
+import org.apache.commons.io.IOUtils;
+import org.apache.commons.lang3.StringUtils;
+
+import com.google.common.base.Joiner;
+import com.google.common.base.Splitter;
+import com.google.common.collect.Iterables;
+import com.google.common.collect.Lists;
+import com.google.common.collect.Sets;
+import com.ibm.icu.text.Transliterator;
+
+import eu.dnetlib.pace.clustering.NGramUtils;
+
+/**
+ * Set of common functions for the framework
+ *
+ * @author claudio
+ */
+public abstract class AbstractPaceFunctions {
+
+	// city map to be used when translating the city names into codes
+	private static Map<String, String> cityMap = AbstractPaceFunctions
+		.loadMapFromClasspath("/eu/dnetlib/pace/config/city_map.csv");
+
+	// list of stopwords in different languages
+	protected static Set<String> stopwords_gr = loadFromClasspath("/eu/dnetlib/pace/config/stopwords_gr.txt");
+	protected static Set<String> stopwords_en = loadFromClasspath("/eu/dnetlib/pace/config/stopwords_en.txt");
+	protected static Set<String> stopwords_de = loadFromClasspath("/eu/dnetlib/pace/config/stopwords_de.txt");
+	protected static Set<String> stopwords_es = loadFromClasspath("/eu/dnetlib/pace/config/stopwords_es.txt");
+	protected static Set<String> stopwords_fr = loadFromClasspath("/eu/dnetlib/pace/config/stopwords_fr.txt");
+	protected static Set<String> stopwords_it = loadFromClasspath("/eu/dnetlib/pace/config/stopwords_it.txt");
+	protected static Set<String> stopwords_pt = loadFromClasspath("/eu/dnetlib/pace/config/stopwords_pt.txt");
+
+	// transliterator
+	protected static Transliterator transliterator = Transliterator.getInstance("Any-Eng");
+
+	// blacklist of ngrams: to avoid generic keys
+	protected static Set<String> ngramBlacklist = loadFromClasspath("/eu/dnetlib/pace/config/ngram_blacklist.txt");
+
+	// html regex for normalization
+	public static final Pattern HTML_REGEX = Pattern.compile("<[^>]*>");
+
+	private static final String alpha = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 ";
+	private static final String aliases_from = "⁰¹²³⁴⁵⁶⁷⁸⁹⁺⁻⁼⁽⁾ⁿ₀₁₂₃₄₅₆₇₈₉₊₋₌₍₎àáâäæãåāèéêëēėęəîïíīįìôöòóœøōõûüùúūßśšłžźżçćčñń";
+	private static final String aliases_to = "0123456789+-=()n0123456789+-=()aaaaaaaaeeeeeeeeiiiiiioooooooouuuuussslzzzcccnn";
+
+	// doi prefix for normalization
+	public static final Pattern DOI_PREFIX = Pattern.compile("(https?:\\/\\/dx\\.doi\\.org\\/)|(doi:)");
+
+	private static Pattern numberPattern = Pattern.compile("-?\\d+(\\.\\d+)?");
+
+	private static Pattern hexUnicodePattern = Pattern.compile("\\\\u(\\p{XDigit}{4})");
+
+	protected String concat(final List<String> l) {
+		return Joiner.on(" ").skipNulls().join(l);
+	}
+
+	protected String cleanup(final String s) {
+		final String s1 = HTML_REGEX.matcher(s).replaceAll("");
+		final String s2 = unicodeNormalization(s1.toLowerCase());
+		final String s3 = nfd(s2);
+		final String s4 = fixXML(s3);
+		final String s5 = s4.replaceAll("([0-9]+)", " $1 ");
+		final String s6 = transliterate(s5);
+		final String s7 = fixAliases(s6);
+		final String s8 = s7.replaceAll("[^\\p{ASCII}]", "");
+		final String s9 = s8.replaceAll("[\\p{Punct}]", " ");
+		final String s10 = s9.replaceAll("\\n", " ");
+		final String s11 = s10.replaceAll("(?m)\\s+", " ");
+		final String s12 = s11.trim();
+		return s12;
+	}
+
+	protected String fixXML(final String a) {
+
+		return a
+			.replaceAll("&ndash;", " ")
+			.replaceAll("&amp;", " ")
+			.replaceAll("&quot;", " ")
+			.replaceAll("&minus;", " ");
+	}
+
+	protected boolean checkNumbers(final String a, final String b) {
+		final String numbersA = getNumbers(a);
+		final String numbersB = getNumbers(b);
+		final String romansA = getRomans(a);
+		final String romansB = getRomans(b);
+		return !numbersA.equals(numbersB) || !romansA.equals(romansB);
+	}
+
+	protected String getRomans(final String s) {
+		final StringBuilder sb = new StringBuilder();
+		for (final String t : s.split(" ")) {
+			sb.append(isRoman(t) ? t : "");
+		}
+		return sb.toString();
+	}
+
+	protected boolean isRoman(final String s) {
+		return s
+			.replaceAll("^M{0,4}(CM|CD|D?C{0,3})(XC|XL|L?X{0,3})(IX|IV|V?I{0,3})$", "qwertyuiop")
+			.equals("qwertyuiop");
+	}
+
+	protected String getNumbers(final String s) {
+		final StringBuilder sb = new StringBuilder();
+		for (final String t : s.split(" ")) {
+			sb.append(isNumber(t) ? t : "");
+		}
+		return sb.toString();
+	}
+
+	public boolean isNumber(String strNum) {
+		if (strNum == null) {
+			return false;
+		}
+		return numberPattern.matcher(strNum).matches();
+	}
+
+	protected static String fixAliases(final String s) {
+		final StringBuilder sb = new StringBuilder();
+
+		s.chars().forEach(ch -> {
+			final int i = StringUtils.indexOf(aliases_from, ch);
+			sb.append(i >= 0 ? aliases_to.charAt(i) : (char) ch);
+		});
+
+		return sb.toString();
+	}
+
+	protected static String transliterate(final String s) {
+		try {
+			return transliterator.transliterate(s);
+		} catch (Exception e) {
+			return s;
+		}
+	}
+
+	protected String removeSymbols(final String s) {
+		final StringBuilder sb = new StringBuilder();
+
+		s.chars().forEach(ch -> {
+			sb.append(StringUtils.contains(alpha, ch) ? (char) ch : ' ');
+		});
+
+		return sb.toString().replaceAll("\\s+", " ");
+	}
+
+	protected boolean notNull(final String s) {
+		return s != null;
+	}
+
+	protected String normalize(final String s) {
+		return fixAliases(transliterate(nfd(unicodeNormalization(s))))
+			.toLowerCase()
+			// do not compact the regexes in a single expression, would cause StackOverflowError in case of large input
+			// strings
+			.replaceAll("[^ \\w]+", "")
+			.replaceAll("(\\p{InCombiningDiacriticalMarks})+", "")
+			.replaceAll("(\\p{Punct})+", " ")
+			.replaceAll("(\\d)+", " ")
+			.replaceAll("(\\n)+", " ")
+			.trim();
+	}
+
+	public String nfd(final String s) {
+		return Normalizer.normalize(s, Normalizer.Form.NFD);
+	}
+
+	public String utf8(final String s) {
+		byte[] bytes = s.getBytes(StandardCharsets.UTF_8);
+		return new String(bytes, StandardCharsets.UTF_8);
+	}
+
+	public String unicodeNormalization(final String s) {
+
+		Matcher m = hexUnicodePattern.matcher(s);
+		StringBuffer buf = new StringBuffer(s.length());
+		while (m.find()) {
+			String ch = String.valueOf((char) Integer.parseInt(m.group(1), 16));
+			m.appendReplacement(buf, Matcher.quoteReplacement(ch));
+		}
+		m.appendTail(buf);
+		return buf.toString();
+	}
+
+	protected String filterStopWords(final String s, final Set<String> stopwords) {
+		final StringTokenizer st = new StringTokenizer(s);
+		final StringBuilder sb = new StringBuilder();
+		while (st.hasMoreTokens()) {
+			final String token = st.nextToken();
+			if (!stopwords.contains(token)) {
+				sb.append(token);
+				sb.append(" ");
+			}
+		}
+		return sb.toString().trim();
+	}
+
+	public String filterAllStopWords(String s) {
+
+		s = filterStopWords(s, stopwords_en);
+		s = filterStopWords(s, stopwords_de);
+		s = filterStopWords(s, stopwords_it);
+		s = filterStopWords(s, stopwords_fr);
+		s = filterStopWords(s, stopwords_pt);
+		s = filterStopWords(s, stopwords_es);
+		s = filterStopWords(s, stopwords_gr);
+
+		return s;
+	}
+
+	protected Collection<String> filterBlacklisted(final Collection<String> set, final Set<String> ngramBlacklist) {
+		final Set<String> newset = Sets.newLinkedHashSet();
+		for (final String s : set) {
+			if (!ngramBlacklist.contains(s)) {
+				newset.add(s);
+			}
+		}
+		return newset;
+	}
+
+	public static Set<String> loadFromClasspath(final String classpath) {
+
+		Transliterator transliterator = Transliterator.getInstance("Any-Eng");
+
+		final Set<String> h = Sets.newHashSet();
+		try {
+			for (final String s : IOUtils
+				.readLines(NGramUtils.class.getResourceAsStream(classpath), StandardCharsets.UTF_8)) {
+				h.add(fixAliases(transliterator.transliterate(s))); // transliteration of the stopwords
+			}
+		} catch (final Throwable e) {
+			return Sets.newHashSet();
+		}
+		return h;
+	}
+
+	public static Map<String, String> loadMapFromClasspath(final String classpath) {
+
+		Transliterator transliterator = Transliterator.getInstance("Any-Eng");
+
+		final Map<String, String> m = new HashMap<>();
+		try {
+			for (final String s : IOUtils
+				.readLines(AbstractPaceFunctions.class.getResourceAsStream(classpath), StandardCharsets.UTF_8)) {
+				// string is like this: code;word1;word2;word3
+				String[] line = s.split(";");
+				String value = line[0];
+				for (int i = 1; i < line.length; i++) {
+					m.put(fixAliases(transliterator.transliterate(line[i].toLowerCase())), value);
+				}
+			}
+		} catch (final Throwable e) {
+			return new HashMap<>();
+		}
+		return m;
+	}
+
+	public String removeKeywords(String s, Set<String> keywords) {
+
+		s = " " + s + " ";
+		for (String k : keywords) {
+			s = s.replaceAll(k.toLowerCase(), "");
+		}
+
+		return s.trim();
+	}
+
+	public double commonElementsPercentage(Set<String> s1, Set<String> s2) {
+
+		double longer = Math.max(s1.size(), s2.size());
+		return (double) s1.stream().filter(s2::contains).count() / longer;
+	}
+
+	// convert the set of keywords to codes
+	public Set<String> toCodes(Set<String> keywords, Map<String, String> translationMap) {
+		return keywords.stream().map(s -> translationMap.get(s)).collect(Collectors.toSet());
+	}
+
+	public Set<String> keywordsToCodes(Set<String> keywords, Map<String, String> translationMap) {
+		return toCodes(keywords, translationMap);
+	}
+
+	public Set<String> citiesToCodes(Set<String> keywords) {
+		return toCodes(keywords, cityMap);
+	}
+
+	protected String firstLC(final String s) {
+		return StringUtils.substring(s, 0, 1).toLowerCase();
+	}
+
+	protected Iterable<String> tokens(final String s, final int maxTokens) {
+		return Iterables.limit(Splitter.on(" ").omitEmptyStrings().trimResults().split(s), maxTokens);
+	}
+
+	public String normalizePid(String pid) {
+		return DOI_PREFIX.matcher(pid.toLowerCase()).replaceAll("");
+	}
+
+	// get the list of keywords into the input string
+	public Set<String> getKeywords(String s1, Map<String, String> translationMap, int windowSize) {
+
+		String s = s1;
+
+		List<String> tokens = Arrays.asList(s.toLowerCase().split(" "));
+
+		Set<String> codes = new HashSet<>();
+
+		if (tokens.size() < windowSize)
+			windowSize = tokens.size();
+
+		int length = windowSize;
+
+		while (length != 0) {
+
+			for (int i = 0; i <= tokens.size() - length; i++) {
+				String candidate = concat(tokens.subList(i, i + length));
+				if (translationMap.containsKey(candidate)) {
+					codes.add(candidate);
+					s = s.replace(candidate, "").trim();
+				}
+			}
+
+			tokens = Arrays.asList(s.split(" "));
+			length -= 1;
+		}
+
+		return codes;
+	}
+
+	public Set<String> getCities(String s1, int windowSize) {
+		return getKeywords(s1, cityMap, windowSize);
+	}
+
+	public static <T> String readFromClasspath(final String filename, final Class<T> clazz) {
+		final StringWriter sw = new StringWriter();
+		try {
+			IOUtils.copy(clazz.getResourceAsStream(filename), sw, StandardCharsets.UTF_8);
+			return sw.toString();
+		} catch (final IOException e) {
+			throw new RuntimeException("cannot load resource from classpath: " + filename);
+		}
+	}
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/config/Config.java

@@ -0,0 +1,53 @@
+
+package eu.dnetlib.pace.config;
+
+import java.util.List;
+import java.util.Map;
+import java.util.function.Predicate;
+
+import eu.dnetlib.pace.model.ClusteringDef;
+import eu.dnetlib.pace.model.FieldDef;
+import eu.dnetlib.pace.tree.support.TreeNodeDef;
+
+/**
+ * Interface for PACE configuration bean.
+ *
+ * @author claudio
+ */
+public interface Config {
+
+	/**
+	 * Field configuration definitions.
+	 *
+	 * @return the list of definitions
+	 */
+	public List<FieldDef> model();
+
+	/**
+	 * Decision Tree definition
+	 *
+	 * @return the map representing the decision tree
+	 */
+	public Map<String, TreeNodeDef> decisionTree();
+
+	/**
+	 * Clusterings.
+	 *
+	 * @return the list
+	 */
+	public List<ClusteringDef> clusterings();
+
+	/**
+	 * Blacklists.
+	 *
+	 * @return the map
+	 */
+	public Map<String, Predicate<String>> blacklists();
+
+	/**
+	 * Translation map.
+	 *
+	 * @return the map
+	 * */
+	public Map<String, String> translationMap();
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/config/DedupConfig.java

@@ -0,0 +1,178 @@
+
+package eu.dnetlib.pace.config;
+
+import java.io.IOException;
+import java.io.Serializable;
+import java.nio.charset.StandardCharsets;
+import java.util.AbstractMap;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.function.Predicate;
+import java.util.regex.Pattern;
+import java.util.regex.PatternSyntaxException;
+import java.util.stream.Collectors;
+
+import org.antlr.stringtemplate.StringTemplate;
+import org.apache.commons.io.IOUtils;
+import org.apache.commons.lang3.StringUtils;
+
+import com.fasterxml.jackson.annotation.JsonIgnore;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.google.common.collect.Maps;
+
+import eu.dnetlib.pace.model.ClusteringDef;
+import eu.dnetlib.pace.model.FieldDef;
+import eu.dnetlib.pace.tree.support.TreeNodeDef;
+import eu.dnetlib.pace.util.PaceException;
+
+public class DedupConfig implements Config, Serializable {
+	private static String CONFIG_TEMPLATE = "dedupConfig.st";
+
+	private PaceConfig pace;
+
+	private WfConfig wf;
+
+	@JsonIgnore
+	private Map<String, Predicate<String>> blacklists;
+
+	private static Map<String, String> defaults = Maps.newHashMap();
+
+	static {
+		defaults.put("dedupRun", "001");
+		defaults.put("entityType", "result");
+		defaults.put("subEntityType", "resulttype");
+		defaults.put("subEntityValue", "publication");
+		defaults.put("orderField", "title");
+		defaults.put("queueMaxSize", "2000");
+		defaults.put("groupMaxSize", "10");
+		defaults.put("slidingWindowSize", "200");
+		defaults.put("rootBuilder", "result");
+		defaults.put("includeChildren", "true");
+		defaults.put("maxIterations", "20");
+		defaults.put("idPath", "$.id");
+	}
+
+	public DedupConfig() {
+	}
+
+	public static DedupConfig load(final String json) {
+
+		final DedupConfig config;
+		try {
+			config = new ObjectMapper().readValue(json, DedupConfig.class);
+			config.getPace().initModel();
+			config.getPace().initTranslationMap();
+
+			config.blacklists = config
+				.getPace()
+				.getBlacklists()
+				.entrySet()
+				.stream()
+				.map(
+					e -> new AbstractMap.SimpleEntry<String, List<Pattern>>(e.getKey(),
+						e
+							.getValue()
+							.stream()
+							.filter(s -> !StringUtils.isBlank(s))
+							.map(Pattern::compile)
+							.collect(Collectors.toList())))
+				.collect(
+					Collectors
+						.toMap(
+							e -> e.getKey(),
+							e -> (Predicate<String> & Serializable) s -> e
+								.getValue()
+								.stream()
+								.filter(p -> p.matcher(s).matches())
+								.findFirst()
+								.isPresent()))
+
+			;
+
+			return config;
+		} catch (IOException | PatternSyntaxException e) {
+			throw new PaceException("Error in parsing configuration json", e);
+		}
+
+	}
+
+	public static DedupConfig loadDefault() throws IOException {
+		return loadDefault(new HashMap<String, String>());
+	}
+
+	public static DedupConfig loadDefault(final Map<String, String> params) throws IOException {
+
+		final StringTemplate template = new StringTemplate(new DedupConfig().readFromClasspath(CONFIG_TEMPLATE));
+
+		for (final Entry<String, String> e : defaults.entrySet()) {
+			template.setAttribute(e.getKey(), e.getValue());
+		}
+		for (final Entry<String, String> e : params.entrySet()) {
+			if (template.getAttribute(e.getKey()) != null) {
+				template.getAttributes().computeIfPresent(e.getKey(), (o, o2) -> e.getValue());
+			} else {
+				template.setAttribute(e.getKey(), e.getValue());
+			}
+		}
+
+		final String json = template.toString();
+		return load(json);
+	}
+
+	private String readFromClasspath(final String resource) throws IOException {
+		return IOUtils.toString(getClass().getResource(resource), StandardCharsets.UTF_8);
+	}
+
+	public PaceConfig getPace() {
+		return pace;
+	}
+
+	public void setPace(final PaceConfig pace) {
+		this.pace = pace;
+	}
+
+	public WfConfig getWf() {
+		return wf;
+	}
+
+	public void setWf(final WfConfig wf) {
+		this.wf = wf;
+	}
+
+	@Override
+	public String toString() {
+		try {
+			return new ObjectMapper().writeValueAsString(this);
+		} catch (IOException e) {
+			throw new PaceException("unable to serialise configuration", e);
+		}
+	}
+
+	@Override
+	public Map<String, TreeNodeDef> decisionTree() {
+		return getPace().getDecisionTree();
+	}
+
+	@Override
+	public List<FieldDef> model() {
+		return getPace().getModel();
+	}
+
+	@Override
+	public List<ClusteringDef> clusterings() {
+		return getPace().getClustering();
+	}
+
+	@Override
+	public Map<String, Predicate<String>> blacklists() {
+		return blacklists;
+	}
+
+	@Override
+	public Map<String, String> translationMap() {
+		return getPace().translationMap();
+	}
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/config/PaceConfig.java

@@ -0,0 +1,108 @@
+
+package eu.dnetlib.pace.config;
+
+import java.io.Serializable;
+import java.util.List;
+import java.util.Map;
+
+import com.fasterxml.jackson.annotation.JsonIgnore;
+import com.google.common.collect.Maps;
+import com.ibm.icu.text.Transliterator;
+
+import eu.dnetlib.pace.common.AbstractPaceFunctions;
+import eu.dnetlib.pace.model.ClusteringDef;
+import eu.dnetlib.pace.model.FieldDef;
+import eu.dnetlib.pace.tree.support.TreeNodeDef;
+import eu.dnetlib.pace.util.PaceResolver;
+
+public class PaceConfig extends AbstractPaceFunctions implements Serializable {
+
+	private List<FieldDef> model;
+
+	private List<ClusteringDef> clustering;
+	private Map<String, TreeNodeDef> decisionTree;
+
+	private Map<String, List<String>> blacklists;
+	private Map<String, List<String>> synonyms;
+
+	@JsonIgnore
+	private Map<String, String> translationMap;
+
+	public Map<String, FieldDef> getModelMap() {
+		return modelMap;
+	}
+
+	@JsonIgnore
+	private Map<String, FieldDef> modelMap;
+
+	@JsonIgnore
+	public static PaceResolver resolver = new PaceResolver();
+
+	public PaceConfig() {
+	}
+
+	public void initModel() {
+		modelMap = Maps.newHashMap();
+		for (FieldDef fd : getModel()) {
+			modelMap.put(fd.getName(), fd);
+		}
+	}
+
+	public void initTranslationMap() {
+		translationMap = Maps.newHashMap();
+
+		Transliterator transliterator = Transliterator.getInstance("Any-Eng");
+		for (String key : synonyms.keySet()) {
+			for (String term : synonyms.get(key)) {
+				translationMap
+					.put(
+						fixAliases(transliterator.transliterate(term.toLowerCase())),
+						key);
+			}
+		}
+	}
+
+	public Map<String, String> translationMap() {
+		return translationMap;
+	}
+
+	public List<FieldDef> getModel() {
+		return model;
+	}
+
+	public void setModel(final List<FieldDef> model) {
+		this.model = model;
+	}
+
+	public List<ClusteringDef> getClustering() {
+		return clustering;
+	}
+
+	public void setClustering(final List<ClusteringDef> clustering) {
+		this.clustering = clustering;
+	}
+
+	public Map<String, TreeNodeDef> getDecisionTree() {
+		return decisionTree;
+	}
+
+	public void setDecisionTree(Map<String, TreeNodeDef> decisionTree) {
+		this.decisionTree = decisionTree;
+	}
+
+	public Map<String, List<String>> getBlacklists() {
+		return blacklists;
+	}
+
+	public void setBlacklists(final Map<String, List<String>> blacklists) {
+		this.blacklists = blacklists;
+	}
+
+	public Map<String, List<String>> getSynonyms() {
+		return synonyms;
+	}
+
+	public void setSynonyms(Map<String, List<String>> synonyms) {
+		this.synonyms = synonyms;
+	}
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/config/Type.java

@@ -0,0 +1,6 @@
+
+package eu.dnetlib.pace.config;
+
+public enum Type {
+	String, Int, List, JSON, URL, StringConcat, DoubleArray
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/config/WfConfig.java

@@ -0,0 +1,294 @@
+
+package eu.dnetlib.pace.config;
+
+import java.io.IOException;
+import java.io.Serializable;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+import org.apache.commons.lang3.StringUtils;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.google.common.collect.Lists;
+import com.google.common.collect.Sets;
+
+import eu.dnetlib.pace.util.PaceException;
+
+public class WfConfig implements Serializable {
+
+	/**
+	 * Entity type.
+	 */
+	private String entityType = "";
+
+	/**
+	 * Sub-Entity type refers to one of fields declared in the model. See eu.dnetlib.pace.config.PaceConfig.modelMap
+	 */
+	private String subEntityType = "";
+
+	/**
+	 * Sub-Entity value declares a value for subTypes to be considered.
+	 */
+	private String subEntityValue = "";
+
+	/**
+	 * Field name used to sort the values in the reducer phase.
+	 */
+	private String orderField = "";
+
+	/**
+	 * Column Families involved in the relations redirection.
+	 */
+	private List<String> rootBuilder = Lists.newArrayList();
+
+	/**
+	 * Set of datasource namespace prefixes that won't be deduplicated.
+	 */
+	private Set<String> skipList = Sets.newHashSet();
+
+	/**
+	 * Subprefix used to build the root id, allows multiple dedup runs.
+	 */
+	private String dedupRun = "";
+
+	/**
+	 * Similarity threshold.
+	 */
+	private double threshold = 0;
+
+	/** The queue max size. */
+	private int queueMaxSize = 2000;
+
+	/** The group max size. */
+	private int groupMaxSize;
+
+	/** The sliding window size. */
+	private int slidingWindowSize;
+
+	/** The configuration id. */
+	private String configurationId;
+
+	/** The include children. */
+	private boolean includeChildren;
+
+	/** Default maximum number of allowed children. */
+	private final static int MAX_CHILDREN = 10;
+
+	/** Maximum number of allowed children. */
+	private int maxChildren = MAX_CHILDREN;
+
+	/** Default maximum number of iterations. */
+	private final static int MAX_ITERATIONS = 20;
+
+	/** Maximum number of iterations */
+	private int maxIterations = MAX_ITERATIONS;
+
+	/** The Jquery path to retrieve the identifier */
+	private String idPath = "$.id";
+
+	public WfConfig() {
+	}
+
+	/**
+	 * Instantiates a new dedup config.
+	 *
+	 * @param entityType
+	 *            the entity type
+	 * @param orderField
+	 *            the order field
+	 * @param rootBuilder
+	 *            the root builder families
+	 * @param dedupRun
+	 *            the dedup run
+	 * @param skipList
+	 *            the skip list
+	 * @param queueMaxSize
+	 *            the queue max size
+	 * @param groupMaxSize
+	 *            the group max size
+	 * @param slidingWindowSize
+	 *            the sliding window size
+	 * @param includeChildren
+	 *            allows the children to be included in the representative records or not.
+	 * @param maxIterations
+	 * 			  the maximum number of iterations
+	 * @param idPath
+	 * 			  the path for the id of the entity
+	 */
+	public WfConfig(final String entityType, final String orderField, final List<String> rootBuilder,
+		final String dedupRun,
+		final Set<String> skipList, final int queueMaxSize, final int groupMaxSize, final int slidingWindowSize,
+		final boolean includeChildren, final int maxIterations, final String idPath) {
+		super();
+		this.entityType = entityType;
+		this.orderField = orderField;
+		this.rootBuilder = rootBuilder;
+		this.dedupRun = cleanupStringNumber(dedupRun);
+		this.skipList = skipList;
+		this.queueMaxSize = queueMaxSize;
+		this.groupMaxSize = groupMaxSize;
+		this.slidingWindowSize = slidingWindowSize;
+		this.includeChildren = includeChildren;
+		this.maxIterations = maxIterations;
+		this.idPath = idPath;
+	}
+
+	/**
+	 * Cleanup string number.
+	 *
+	 * @param s
+	 *            the s
+	 * @return the string
+	 */
+	private String cleanupStringNumber(final String s) {
+		return s.contains("'") ? s.replaceAll("'", "") : s;
+	}
+
+	public boolean hasSubType() {
+		return StringUtils.isNotBlank(getSubEntityType()) && StringUtils.isNotBlank(getSubEntityValue());
+	}
+
+	public String getEntityType() {
+		return entityType;
+	}
+
+	public void setEntityType(final String entityType) {
+		this.entityType = entityType;
+	}
+
+	public String getSubEntityType() {
+		return subEntityType;
+	}
+
+	public void setSubEntityType(final String subEntityType) {
+		this.subEntityType = subEntityType;
+	}
+
+	public String getSubEntityValue() {
+		return subEntityValue;
+	}
+
+	public void setSubEntityValue(final String subEntityValue) {
+		this.subEntityValue = subEntityValue;
+	}
+
+	public String getOrderField() {
+		return orderField;
+	}
+
+	public void setOrderField(final String orderField) {
+		this.orderField = orderField;
+	}
+
+	public List<String> getRootBuilder() {
+		return rootBuilder;
+	}
+
+	public void setRootBuilder(final List<String> rootBuilder) {
+		this.rootBuilder = rootBuilder;
+	}
+
+	public Set<String> getSkipList() {
+		return skipList != null ? skipList : new HashSet<String>();
+	}
+
+	public void setSkipList(final Set<String> skipList) {
+		this.skipList = skipList;
+	}
+
+	public String getDedupRun() {
+		return dedupRun;
+	}
+
+	public void setDedupRun(final String dedupRun) {
+		this.dedupRun = dedupRun;
+	}
+
+	public double getThreshold() {
+		return threshold;
+	}
+
+	public void setThreshold(final double threshold) {
+		this.threshold = threshold;
+	}
+
+	public int getQueueMaxSize() {
+		return queueMaxSize;
+	}
+
+	public void setQueueMaxSize(final int queueMaxSize) {
+		this.queueMaxSize = queueMaxSize;
+	}
+
+	public int getGroupMaxSize() {
+		return groupMaxSize;
+	}
+
+	public void setGroupMaxSize(final int groupMaxSize) {
+		this.groupMaxSize = groupMaxSize;
+	}
+
+	public int getSlidingWindowSize() {
+		return slidingWindowSize;
+	}
+
+	public void setSlidingWindowSize(final int slidingWindowSize) {
+		this.slidingWindowSize = slidingWindowSize;
+	}
+
+	public String getConfigurationId() {
+		return configurationId;
+	}
+
+	public void setConfigurationId(final String configurationId) {
+		this.configurationId = configurationId;
+	}
+
+	public boolean isIncludeChildren() {
+		return includeChildren;
+	}
+
+	public void setIncludeChildren(final boolean includeChildren) {
+		this.includeChildren = includeChildren;
+	}
+
+	public int getMaxChildren() {
+		return maxChildren;
+	}
+
+	public void setMaxChildren(final int maxChildren) {
+		this.maxChildren = maxChildren;
+	}
+
+	public int getMaxIterations() {
+		return maxIterations;
+	}
+
+	public void setMaxIterations(int maxIterations) {
+		this.maxIterations = maxIterations;
+	}
+
+	public String getIdPath() {
+		return idPath;
+	}
+
+	public void setIdPath(String idPath) {
+		this.idPath = idPath;
+
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see java.lang.Object#toString()
+	 */
+	@Override
+	public String toString() {
+		try {
+			return new ObjectMapper().writeValueAsString(this);
+		} catch (IOException e) {
+			throw new PaceException("unable to serialise " + this.getClass().getName(), e);
+		}
+	}
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/model/ClusteringDef.java

@@ -0,0 +1,63 @@
+
+package eu.dnetlib.pace.model;
+
+import java.io.IOException;
+import java.io.Serializable;
+import java.util.List;
+import java.util.Map;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+import eu.dnetlib.pace.clustering.ClusteringFunction;
+import eu.dnetlib.pace.config.PaceConfig;
+import eu.dnetlib.pace.util.PaceException;
+
+public class ClusteringDef implements Serializable {
+
+	private String name;
+
+	private List<String> fields;
+
+	private Map<String, Integer> params;
+
+	public ClusteringDef() {
+	}
+
+	public String getName() {
+		return name;
+	}
+
+	public void setName(final String name) {
+		this.name = name;
+	}
+
+	public ClusteringFunction clusteringFunction() {
+		return PaceConfig.resolver.getClusteringFunction(getName(), params);
+	}
+
+	public List<String> getFields() {
+		return fields;
+	}
+
+	public void setFields(final List<String> fields) {
+		this.fields = fields;
+	}
+
+	public Map<String, Integer> getParams() {
+		return params;
+	}
+
+	public void setParams(final Map<String, Integer> params) {
+		this.params = params;
+	}
+
+	@Override
+	public String toString() {
+		try {
+			return new ObjectMapper().writeValueAsString(this);
+		} catch (IOException e) {
+			throw new PaceException("unable to serialise " + this.getClass().getName(), e);
+		}
+	}
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/model/FieldDef.java

@@ -0,0 +1,103 @@
+
+package eu.dnetlib.pace.model;
+
+import java.io.Serializable;
+import java.util.List;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.google.common.base.Splitter;
+import com.google.common.collect.Lists;
+
+import eu.dnetlib.pace.config.Type;
+
+/**
+ * The schema is composed by field definitions (FieldDef). Each field has a type, a name, and an associated compare algorithm.
+ */
+public class FieldDef implements Serializable {
+
+	public final static String PATH_SEPARATOR = "/";
+
+	private String name;
+
+	private String path;
+
+	private Type type;
+
+	private boolean overrideMatch;
+
+	/**
+	 * Sets maximum size for the repeatable fields in the model. -1 for unbounded size.
+	 */
+	private int size = -1;
+
+	/**
+	 * Sets maximum length for field values in the model. -1 for unbounded length.
+	 */
+	private int length = -1;
+
+	public FieldDef() {
+	}
+
+	public String getName() {
+		return name;
+	}
+
+	public String getPath() {
+		return path;
+	}
+
+	public List<String> getPathList() {
+		return Lists.newArrayList(Splitter.on(PATH_SEPARATOR).split(getPath()));
+	}
+
+	public Type getType() {
+		return type;
+	}
+
+	public void setType(final Type type) {
+		this.type = type;
+	}
+
+	public boolean isOverrideMatch() {
+		return overrideMatch;
+	}
+
+	public void setOverrideMatch(final boolean overrideMatch) {
+		this.overrideMatch = overrideMatch;
+	}
+
+	public int getSize() {
+		return size;
+	}
+
+	public void setSize(int size) {
+		this.size = size;
+	}
+
+	public int getLength() {
+		return length;
+	}
+
+	public void setLength(int length) {
+		this.length = length;
+	}
+
+	public void setName(String name) {
+		this.name = name;
+	}
+
+	public void setPath(String path) {
+		this.path = path;
+	}
+
+	@Override
+	public String toString() {
+		try {
+			return new ObjectMapper().writeValueAsString(this);
+		} catch (JsonProcessingException e) {
+			return null;
+		}
+	}
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/model/Person.java

@@ -0,0 +1,156 @@
+
+package eu.dnetlib.pace.model;
+
+import java.nio.charset.Charset;
+import java.text.Normalizer;
+import java.util.List;
+import java.util.Set;
+
+import com.google.common.base.Joiner;
+import com.google.common.base.Splitter;
+import com.google.common.collect.Iterables;
+import com.google.common.collect.Lists;
+import com.google.common.hash.Hashing;
+
+import eu.dnetlib.pace.common.AbstractPaceFunctions;
+import eu.dnetlib.pace.util.Capitalise;
+import eu.dnetlib.pace.util.DotAbbreviations;
+
+public class Person {
+
+	private static final String UTF8 = "UTF-8";
+	private List<String> name = Lists.newArrayList();
+	private List<String> surname = Lists.newArrayList();
+	private List<String> fullname = Lists.newArrayList();
+	private final String original;
+
+	private static Set<String> particles = null;
+
+	public Person(String s, final boolean aggressive) {
+		original = s;
+		s = Normalizer.normalize(s, Normalizer.Form.NFD);
+		s = s.replaceAll("\\(.+\\)", "");
+		s = s.replaceAll("\\[.+\\]", "");
+		s = s.replaceAll("\\{.+\\}", "");
+		s = s.replaceAll("\\s+-\\s+", "-");
+		s = s.replaceAll("[\\p{Punct}&&[^,-]]", " ");
+		s = s.replaceAll("\\d", " ");
+		s = s.replaceAll("\\n", " ");
+		s = s.replaceAll("\\.", " ");
+		s = s.replaceAll("\\s+", " ");
+
+		if (aggressive) {
+			s = s.replaceAll("[\\p{InCombiningDiacriticalMarks}&&[^,-]]", "");
+			// s = s.replaceAll("[\\W&&[^,-]]", "");
+		}
+
+		if (s.contains(",")) { // if the name contains a comma it is easy derivable the name and the surname
+			final String[] arr = s.split(",");
+			if (arr.length == 1) {
+				fullname = splitTerms(arr[0]);
+			} else if (arr.length > 1) {
+				surname = splitTerms(arr[0]);
+				name = splitTerms(arr[1]);
+				fullname.addAll(surname);
+				fullname.addAll(name);
+			}
+		} else {
+			fullname = splitTerms(s);
+
+			int lastInitialPosition = fullname.size();
+			boolean hasSurnameInUpperCase = false;
+
+			for (int i = 0; i < fullname.size(); i++) {
+				final String term = fullname.get(i);
+				if (term.length() == 1) {
+					lastInitialPosition = i;
+				} else if (term.equals(term.toUpperCase())) {
+					hasSurnameInUpperCase = true;
+				}
+			}
+
+			if (lastInitialPosition < (fullname.size() - 1)) { // Case: Michele G. Artini
+				name = fullname.subList(0, lastInitialPosition + 1);
+				surname = fullname.subList(lastInitialPosition + 1, fullname.size());
+			} else if (hasSurnameInUpperCase) { // Case: Michele ARTINI
+				for (final String term : fullname) {
+					if ((term.length() > 1) && term.equals(term.toUpperCase())) {
+						surname.add(term);
+					} else {
+						name.add(term);
+					}
+				}
+			}
+		}
+	}
+
+	private List<String> splitTerms(final String s) {
+		if (particles == null) {
+			particles = AbstractPaceFunctions.loadFromClasspath("/eu/dnetlib/pace/config/name_particles.txt");
+		}
+
+		final List<String> list = Lists.newArrayList();
+		for (final String part : Splitter.on(" ").omitEmptyStrings().split(s)) {
+			if (!particles.contains(part.toLowerCase())) {
+				list.add(part);
+			}
+		}
+		return list;
+	}
+
+	public List<String> getName() {
+		return name;
+	}
+
+	public String getNameString() {
+		return Joiner.on(" ").join(getName());
+	}
+
+	public List<String> getSurname() {
+		return surname;
+	}
+
+	public List<String> getFullname() {
+		return fullname;
+	}
+
+	public String getOriginal() {
+		return original;
+	}
+
+	public String hash() {
+		return Hashing.murmur3_128().hashString(getNormalisedFullname(), Charset.forName(UTF8)).toString();
+	}
+
+	public String getNormalisedFirstName() {
+		return Joiner.on(" ").join(getCapitalFirstnames());
+	}
+
+	public String getNormalisedSurname() {
+		return Joiner.on(" ").join(getCapitalSurname());
+	}
+
+	public String getSurnameString() {
+		return Joiner.on(" ").join(getSurname());
+	}
+
+	public String getNormalisedFullname() {
+		return isAccurate() ? getNormalisedSurname() + ", " + getNormalisedFirstName() : Joiner.on(" ").join(fullname);
+	}
+
+	public List<String> getCapitalFirstnames() {
+		return Lists.newArrayList(Iterables.transform(getNameWithAbbreviations(), new Capitalise()));
+	}
+
+	public List<String> getCapitalSurname() {
+		return Lists.newArrayList(Iterables.transform(surname, new Capitalise()));
+	}
+
+	public List<String> getNameWithAbbreviations() {
+		return Lists.newArrayList(Iterables.transform(name, new DotAbbreviations()));
+	}
+
+	public boolean isAccurate() {
+		return ((name != null) && (surname != null) && !name.isEmpty() && !surname.isEmpty());
+	}
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/model/PersonComparatorUtils.java

@@ -0,0 +1,119 @@
+
+package eu.dnetlib.pace.model;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.Set;
+
+import com.google.common.collect.Lists;
+import com.google.common.collect.Sets;
+
+public class PersonComparatorUtils {
+
+	private static final int MAX_FULLNAME_LENGTH = 50;
+
+	public static Set<String> getNgramsForPerson(String fullname) {
+
+		Set<String> set = Sets.newHashSet();
+
+		if (fullname.length() > MAX_FULLNAME_LENGTH) {
+			return set;
+		}
+
+		Person p = new Person(fullname, true);
+
+		if (p.isAccurate()) {
+			for (String name : p.getName()) {
+				for (String surname : p.getSurname()) {
+					set.add((name.charAt(0) + "_" + surname).toLowerCase());
+				}
+			}
+		} else {
+			List<String> list = p.getFullname();
+			for (int i = 0; i < list.size(); i++) {
+				if (list.get(i).length() > 1) {
+					for (int j = 0; j < list.size(); j++) {
+						if (i != j) {
+							set.add((list.get(j).charAt(0) + "_" + list.get(i)).toLowerCase());
+						}
+					}
+				}
+			}
+		}
+
+		return set;
+	}
+
+	public static boolean areSimilar(String s1, String s2) {
+		Person p1 = new Person(s1, true);
+		Person p2 = new Person(s2, true);
+
+		if (p1.isAccurate() && p2.isAccurate()) {
+			return verifyNames(p1.getName(), p2.getName()) && verifySurnames(p1.getSurname(), p2.getSurname());
+		} else {
+			return verifyFullnames(p1.getFullname(), p2.getFullname());
+		}
+	}
+
+	private static boolean verifyNames(List<String> list1, List<String> list2) {
+		return verifySimilarity(extractExtendedNames(list1), extractExtendedNames(list2))
+			&& verifySimilarity(extractInitials(list1), extractInitials(list2));
+	}
+
+	private static boolean verifySurnames(List<String> list1, List<String> list2) {
+		if (list1.size() != list2.size()) {
+			return false;
+		}
+		for (int i = 0; i < list1.size(); i++) {
+			if (!list1.get(i).equalsIgnoreCase(list2.get(i))) {
+				return false;
+			}
+		}
+		return true;
+	}
+
+	private static boolean verifyFullnames(List<String> list1, List<String> list2) {
+		Collections.sort(list1);
+		Collections.sort(list2);
+		return verifySimilarity(extractExtendedNames(list1), extractExtendedNames(list2))
+			&& verifySimilarity(extractInitials(list1), extractInitials(list2));
+	}
+
+	private static List<String> extractExtendedNames(List<String> list) {
+		ArrayList<String> res = Lists.newArrayList();
+		for (String s : list) {
+			if (s.length() > 1) {
+				res.add(s.toLowerCase());
+			}
+		}
+		return res;
+	}
+
+	private static List<String> extractInitials(List<String> list) {
+		ArrayList<String> res = Lists.newArrayList();
+		for (String s : list) {
+			res.add(s.substring(0, 1).toLowerCase());
+		}
+		return res;
+	}
+
+	private static boolean verifySimilarity(List<String> list1, List<String> list2) {
+		if (list1.size() > list2.size()) {
+			return verifySimilarity(list2, list1);
+		}
+
+		// NB: List2 is greater than list1 (or equal)
+		int pos = -1;
+		for (String s : list1) {
+			int curr = list2.indexOf(s);
+			if (curr > pos) {
+				list2.set(curr, "*"); // I invalidate the found element, example: "amm - amm"
+				pos = curr;
+			} else {
+				return false;
+			}
+		}
+		return true;
+	}
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/model/RowDataOrderingComparator.java

@@ -0,0 +1,65 @@
+
+package eu.dnetlib.pace.model;
+
+import java.util.Comparator;
+
+import org.apache.spark.sql.Row;
+
+import eu.dnetlib.pace.clustering.NGramUtils;
+
+/**
+ * The Class MapDocumentComparator.
+ */
+public class RowDataOrderingComparator implements Comparator<Row> {
+
+	/** The comparator field. */
+	private final int comparatorField;
+	private final int identityFieldPosition;
+
+	/**
+	 * Instantiates a new map document comparator.
+	 *
+	 * @param comparatorField
+	 *            the comparator field
+	 */
+	public RowDataOrderingComparator(final int comparatorField, int identityFieldPosition) {
+		this.comparatorField = comparatorField;
+		this.identityFieldPosition = identityFieldPosition;
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see java.util.Comparator#compare(java.lang.Object, java.lang.Object)
+	 */
+	@Override
+	public int compare(final Row d1, final Row d2) {
+		if (d1 == null)
+			return d2 == null ? 0 : -1;
+		else if (d2 == null) {
+			return 1;
+		}
+
+		final String o1 = d1.getString(comparatorField);
+		final String o2 = d2.getString(comparatorField);
+
+		if (o1 == null)
+			return o2 == null ? 0 : -1;
+		else if (o2 == null) {
+			return 1;
+		}
+
+		final String to1 = NGramUtils.cleanupForOrdering(o1);
+		final String to2 = NGramUtils.cleanupForOrdering(o2);
+
+		int res = to1.compareTo(to2);
+		if (res == 0) {
+			res = o1.compareTo(o2);
+			if (res == 0) {
+				return d1.getString(identityFieldPosition).compareTo(d2.getString(identityFieldPosition));
+			}
+		}
+
+		return res;
+	}
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/model/SparkDeduper.scala

@@ -0,0 +1,131 @@
+package eu.dnetlib.pace.model
+
+import eu.dnetlib.pace.config.{DedupConfig, Type}
+import eu.dnetlib.pace.util.{BlockProcessor, SparkReporter}
+import org.apache.spark.SparkContext
+import org.apache.spark.sql.catalyst.expressions.Literal
+import org.apache.spark.sql.expressions._
+import org.apache.spark.sql.functions.{col, lit, udf}
+import org.apache.spark.sql.types._
+import org.apache.spark.sql.{Column, Dataset, Row, functions}
+
+import java.util.function.Predicate
+import java.util.stream.Collectors
+import scala.collection.JavaConversions._
+import scala.collection.JavaConverters._
+import scala.collection.mutable
+case class SparkDeduper(conf: DedupConfig) extends Serializable {
+
+  val model: SparkModel = SparkModel(conf)
+
+  val dedup: (Dataset[Row] => Dataset[Row]) = df => {
+    df.transform(filterAndCleanup)
+      .transform(generateClustersWithCollect)
+      .transform(processBlocks)
+  }
+
+
+  val filterAndCleanup: (Dataset[Row] => Dataset[Row]) = df => {
+    val df_with_filters = conf.getPace.getModel.asScala.foldLeft(df)((res, fdef) => {
+      if (conf.blacklists.containsKey(fdef.getName)) {
+        res.withColumn(
+          fdef.getName + "_filtered",
+          filterColumnUDF(fdef).apply(new Column(fdef.getName))
+        )
+      } else {
+        res
+      }
+    })
+
+    df_with_filters
+  }
+
+  def filterColumnUDF(fdef: FieldDef): UserDefinedFunction = {
+    val blacklist: Predicate[String] = conf.blacklists().get(fdef.getName)
+
+    if (blacklist == null) {
+      throw new IllegalArgumentException("Column: " + fdef.getName + " does not have any filter")
+    } else {
+      fdef.getType match {
+        case Type.List | Type.JSON =>
+          udf[Array[String], Array[String]](values => {
+            values.filter((v: String) => !blacklist.test(v))
+          })
+
+        case _ =>
+          udf[String, String](v => {
+            if (blacklist.test(v)) ""
+            else v
+          })
+      }
+    }
+  }
+
+  val generateClustersWithCollect: (Dataset[Row] => Dataset[Row]) = df_with_filters => {
+    var df_with_clustering_keys: Dataset[Row] = null
+
+    for ((cd, idx) <- conf.clusterings().zipWithIndex) {
+      val inputColumns = cd.getFields().foldLeft(Seq[Column]())((acc, fName) => {
+        val column = if (conf.blacklists.containsKey(fName))
+          Seq(col(fName + "_filtered"))
+        else
+          Seq(col(fName))
+
+        acc ++ column
+      })
+
+      // Add 'key' column with the value generated by the given clustering definition
+      val ds: Dataset[Row] = df_with_filters
+        .withColumn("clustering", lit(cd.getName + "::" + idx))
+        .withColumn("key", functions.explode(clusterValuesUDF(cd).apply(functions.array(inputColumns: _*))))
+        // Add position column having the position of the row within the set of rows having the same key value ordered by the sorting value
+        .withColumn("position", functions.row_number().over(Window.partitionBy("key").orderBy(col(model.orderingFieldName), col(model.identifierFieldName))))
+
+      if (df_with_clustering_keys == null)
+        df_with_clustering_keys = ds
+      else
+        df_with_clustering_keys = df_with_clustering_keys.union(ds)
+    }
+
+    //TODO: analytics
+
+    val df_with_blocks = df_with_clustering_keys
+      // filter out rows with position exceeding the maxqueuesize parameter
+      .filter(col("position").leq(conf.getWf.getQueueMaxSize))
+      .groupBy("clustering", "key")
+      .agg(functions.collect_set(functions.struct(model.schema.fieldNames.map(col): _*)).as("block"))
+      .filter(functions.size(new Column("block")).gt(1))
+
+    df_with_blocks
+  }
+
+  def clusterValuesUDF(cd: ClusteringDef) = {
+    udf[mutable.WrappedArray[String], mutable.WrappedArray[Any]](values => {
+      values.flatMap(f => cd.clusteringFunction().apply(conf, Seq(f.toString).asJava).asScala)
+    })
+  }
+
+  val processBlocks: (Dataset[Row] => Dataset[Row]) = df => {
+    df.filter(functions.size(new Column("block")).geq(new Literal(2, DataTypes.IntegerType)))
+      .withColumn("relations", processBlock(df.sqlContext.sparkContext).apply(new Column("block")))
+      .select(functions.explode(new Column("relations")).as("relation"))
+  }
+
+  def processBlock(implicit sc: SparkContext) = {
+    val accumulators = SparkReporter.constructAccumulator(conf, sc)
+
+    udf[Array[(String, String)], mutable.WrappedArray[Row]](block => {
+      val reporter = new SparkReporter(accumulators)
+
+      val mapDocuments = block.asJava.stream()
+        .sorted(new RowDataOrderingComparator(model.orderingFieldPosition, model.identityFieldPosition))
+        .limit(conf.getWf.getQueueMaxSize)
+        .collect(Collectors.toList[Row]())
+
+      new BlockProcessor(conf, model.identityFieldPosition, model.orderingFieldPosition).processSortedRows(mapDocuments, reporter)
+
+      reporter.getRelations.asScala.toArray
+    }).asNondeterministic()
+  }
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/model/SparkModel.scala

@@ -0,0 +1,108 @@
+package eu.dnetlib.pace.model
+
+import com.jayway.jsonpath.{Configuration, JsonPath}
+import eu.dnetlib.pace.config.{DedupConfig, Type}
+import eu.dnetlib.pace.util.MapDocumentUtil
+import org.apache.spark.sql.catalyst.encoders.RowEncoder
+import org.apache.spark.sql.catalyst.expressions.GenericRowWithSchema
+import org.apache.spark.sql.types.{DataTypes, Metadata, StructField, StructType}
+import org.apache.spark.sql.{Dataset, Row}
+
+import java.util.regex.Pattern
+import scala.collection.JavaConverters._
+
+case class SparkModel(conf: DedupConfig) {
+  private val URL_REGEX: Pattern = Pattern.compile("^\\s*(http|https|ftp)\\://.*")
+
+  private val CONCAT_REGEX: Pattern = Pattern.compile("\\|\\|\\|")
+
+  val identifierFieldName = "identifier"
+
+  val orderingFieldName = if (!conf.getWf.getOrderField.isEmpty) conf.getWf.getOrderField else identifierFieldName
+
+  val schema: StructType = {
+    // create an implicit identifier field
+    val identifier = new FieldDef()
+    identifier.setName(identifierFieldName)
+    identifier.setType(Type.String)
+
+    // Construct a Spark StructType representing the schema of the model
+    (Seq(identifier) ++ conf.getPace.getModel.asScala)
+      .foldLeft(
+        new StructType()
+      )((resType, fieldDef) => {
+        resType.add(fieldDef.getType match {
+          case Type.List | Type.JSON =>
+            StructField(fieldDef.getName, DataTypes.createArrayType(DataTypes.StringType), true, Metadata.empty)
+          case Type.DoubleArray =>
+            StructField(fieldDef.getName, DataTypes.createArrayType(DataTypes.DoubleType), true, Metadata.empty)
+          case _ =>
+            StructField(fieldDef.getName, DataTypes.StringType, true, Metadata.empty)
+        })
+      })
+
+
+  }
+
+  val identityFieldPosition: Int = schema.fieldIndex(identifierFieldName)
+
+  val orderingFieldPosition: Int = schema.fieldIndex(orderingFieldName)
+
+  val parseJsonDataset: (Dataset[String] => Dataset[Row]) = df => {
+    df.map(r => rowFromJson(r))(RowEncoder(schema))
+  }
+
+  def rowFromJson(json: String): Row = {
+    val documentContext =
+      JsonPath.using(Configuration.defaultConfiguration.addOptions(com.jayway.jsonpath.Option.SUPPRESS_EXCEPTIONS)).parse(json)
+    val values = new Array[Any](schema.size)
+
+    values(identityFieldPosition) = MapDocumentUtil.getJPathString(conf.getWf.getIdPath, documentContext)
+
+    schema.fieldNames.zipWithIndex.foldLeft(values) {
+      case ((res, (fname, index))) => {
+        val fdef = conf.getPace.getModelMap.get(fname)
+
+        if (fdef != null) {
+          res(index) = fdef.getType match {
+            case Type.String | Type.Int =>
+              MapDocumentUtil.truncateValue(
+                MapDocumentUtil.getJPathString(fdef.getPath, documentContext),
+                fdef.getLength
+              )
+
+            case Type.URL =>
+              var uv = MapDocumentUtil.getJPathString(fdef.getPath, documentContext)
+              if (!URL_REGEX.matcher(uv).matches)
+                uv = ""
+              uv
+
+            case Type.List | Type.JSON =>
+              MapDocumentUtil.truncateList(
+                MapDocumentUtil.getJPathList(fdef.getPath, documentContext, fdef.getType),
+                fdef.getSize
+              ).toArray
+
+            case Type.StringConcat =>
+              val jpaths = CONCAT_REGEX.split(fdef.getPath)
+
+              MapDocumentUtil.truncateValue(
+                jpaths
+                  .map(jpath => MapDocumentUtil.getJPathString(jpath, documentContext))
+                  .mkString(" "),
+                fdef.getLength
+              )
+
+            case Type.DoubleArray =>
+              MapDocumentUtil.getJPathArray(fdef.getPath, json)
+          }
+        }
+
+        res
+      }
+    }
+
+    new GenericRowWithSchema(values, schema)
+  }
+}
+

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/AlwaysMatch.java

@@ -0,0 +1,42 @@
+
+package eu.dnetlib.pace.tree;
+
+import java.util.Map;
+
+import com.wcohen.ss.AbstractStringDistance;
+
+import eu.dnetlib.pace.config.Config;
+import eu.dnetlib.pace.tree.support.AbstractComparator;
+import eu.dnetlib.pace.tree.support.ComparatorClass;
+
+@ComparatorClass("alwaysMatch")
+public class AlwaysMatch<T> extends AbstractComparator<T> {
+
+	public AlwaysMatch(final Map<String, String> params) {
+		super(params, new com.wcohen.ss.JaroWinkler());
+	}
+
+	public AlwaysMatch(final double weight) {
+		super(weight, new com.wcohen.ss.JaroWinkler());
+	}
+
+	protected AlwaysMatch(final double weight, final AbstractStringDistance ssalgo) {
+		super(weight, ssalgo);
+	}
+
+	@Override
+	public double compare(final Object a, final Object b, final Config conf) {
+		return 1.0;
+	}
+
+	@Override
+	public double getWeight() {
+		return super.weight;
+	}
+
+	@Override
+	protected double normalize(final double d) {
+		return d;
+	}
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/AuthorsMatch.java

@@ -0,0 +1,157 @@
+
+package eu.dnetlib.pace.tree;
+
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+import com.wcohen.ss.AbstractStringDistance;
+
+import eu.dnetlib.pace.config.Config;
+import eu.dnetlib.pace.model.Person;
+import eu.dnetlib.pace.tree.support.AbstractListComparator;
+import eu.dnetlib.pace.tree.support.ComparatorClass;
+
+@ComparatorClass("authorsMatch")
+public class AuthorsMatch extends AbstractListComparator {
+
+	Map<String, String> params;
+
+	private double SURNAME_THRESHOLD;
+	private double NAME_THRESHOLD;
+	private double FULLNAME_THRESHOLD;
+	private String MODE; // full or surname
+	private int SIZE_THRESHOLD;
+	private String TYPE; // count or percentage
+	private int common;
+
+	public AuthorsMatch(Map<String, String> params) {
+		super(params, new com.wcohen.ss.JaroWinkler());
+		this.params = params;
+
+		MODE = params.getOrDefault("mode", "full");
+		SURNAME_THRESHOLD = Double.parseDouble(params.getOrDefault("surname_th", "0.95"));
+		NAME_THRESHOLD = Double.parseDouble(params.getOrDefault("name_th", "0.95"));
+		FULLNAME_THRESHOLD = Double.parseDouble(params.getOrDefault("fullname_th", "0.9"));
+		SIZE_THRESHOLD = Integer.parseInt(params.getOrDefault("size_th", "20"));
+		TYPE = params.getOrDefault("type", "percentage");
+		common = 0;
+	}
+
+	protected AuthorsMatch(double w, AbstractStringDistance ssalgo) {
+		super(w, ssalgo);
+	}
+
+	@Override
+	public double compare(final List<String> a, final List<String> b, final Config conf) {
+
+		if (a.isEmpty() || b.isEmpty())
+			return -1;
+
+		if (a.size() > SIZE_THRESHOLD || b.size() > SIZE_THRESHOLD)
+			return 1.0;
+
+		List<Person> aList = a.stream().map(author -> new Person(author, false)).collect(Collectors.toList());
+		List<Person> bList = b.stream().map(author -> new Person(author, false)).collect(Collectors.toList());
+
+		common = 0;
+		// compare each element of List1 with each element of List2
+		for (Person p1 : aList)
+
+			for (Person p2 : bList) {
+
+				// both persons are inaccurate
+				if (!p1.isAccurate() && !p2.isAccurate()) {
+					// compare just normalized fullnames
+					String fullname1 = normalization(
+						p1.getNormalisedFullname().isEmpty() ? p1.getOriginal() : p1.getNormalisedFullname());
+					String fullname2 = normalization(
+						p2.getNormalisedFullname().isEmpty() ? p2.getOriginal() : p2.getNormalisedFullname());
+
+					if (ssalgo.score(fullname1, fullname2) > FULLNAME_THRESHOLD) {
+						common += 1;
+						break;
+					}
+				}
+
+				// one person is inaccurate
+				if (p1.isAccurate() ^ p2.isAccurate()) {
+					// prepare data
+					// data for the accurate person
+					String name = normalization(
+						p1.isAccurate() ? p1.getNormalisedFirstName() : p2.getNormalisedFirstName());
+					String surname = normalization(
+						p1.isAccurate() ? p1.getNormalisedSurname() : p2.getNormalisedSurname());
+
+					// data for the inaccurate person
+					String fullname = normalization(
+						p1.isAccurate()
+							? ((p2.getNormalisedFullname().isEmpty()) ? p2.getOriginal() : p2.getNormalisedFullname())
+							: (p1.getNormalisedFullname().isEmpty() ? p1.getOriginal() : p1.getNormalisedFullname()));
+
+					if (fullname.contains(surname)) {
+						if (MODE.equals("full")) {
+							if (fullname.contains(name)) {
+								common += 1;
+								break;
+							}
+						} else { // MODE equals "surname"
+							common += 1;
+							break;
+						}
+					}
+				}
+
+				// both persons are accurate
+				if (p1.isAccurate() && p2.isAccurate()) {
+
+					if (compareSurname(p1, p2)) {
+						if (MODE.equals("full")) {
+							if (compareFirstname(p1, p2)) {
+								common += 1;
+								break;
+							}
+						} else { // MODE equals "surname"
+							common += 1;
+							break;
+						}
+					}
+
+				}
+
+			}
+
+		// normalization factor to compute the score
+		int normFactor = aList.size() == bList.size() ? aList.size() : (aList.size() + bList.size() - common);
+
+		if (TYPE.equals("percentage")) {
+			return (double) common / normFactor;
+		} else {
+			return (double) common;
+		}
+	}
+
+	public boolean compareSurname(Person p1, Person p2) {
+		return ssalgo
+			.score(
+				normalization(p1.getNormalisedSurname()), normalization(p2.getNormalisedSurname())) > SURNAME_THRESHOLD;
+	}
+
+	public boolean compareFirstname(Person p1, Person p2) {
+
+		if (p1.getNormalisedFirstName().length() <= 2 || p2.getNormalisedFirstName().length() <= 2) {
+			if (firstLC(p1.getNormalisedFirstName()).equals(firstLC(p2.getNormalisedFirstName())))
+				return true;
+		}
+
+		return ssalgo
+			.score(
+				normalization(p1.getNormalisedFirstName()),
+				normalization(p2.getNormalisedFirstName())) > NAME_THRESHOLD;
+	}
+
+	public String normalization(String s) {
+		return normalize(utf8(cleanup(s)));
+	}
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/CityMatch.java

@@ -0,0 +1,48 @@
+
+package eu.dnetlib.pace.tree;
+
+import java.util.Map;
+import java.util.Set;
+
+import eu.dnetlib.pace.config.Config;
+import eu.dnetlib.pace.tree.support.AbstractStringComparator;
+import eu.dnetlib.pace.tree.support.ComparatorClass;
+
+@ComparatorClass("cityMatch")
+public class CityMatch extends AbstractStringComparator {
+
+	private Map<String, String> params;
+
+	public CityMatch(Map<String, String> params) {
+		super(params);
+		this.params = params;
+	}
+
+	@Override
+	public double distance(final String a, final String b, final Config conf) {
+
+		String ca = cleanup(a);
+		String cb = cleanup(b);
+
+		ca = normalize(ca);
+		cb = normalize(cb);
+
+		ca = filterAllStopWords(ca);
+		cb = filterAllStopWords(cb);
+
+		Set<String> cities1 = getCities(ca, Integer.parseInt(params.getOrDefault("windowSize", "4")));
+		Set<String> cities2 = getCities(cb, Integer.parseInt(params.getOrDefault("windowSize", "4")));
+
+		Set<String> codes1 = citiesToCodes(cities1);
+		Set<String> codes2 = citiesToCodes(cities2);
+
+		// if no cities are detected, the comparator gives 1.0
+		if (codes1.isEmpty() && codes2.isEmpty())
+			return 1.0;
+		else {
+			if (codes1.isEmpty() ^ codes2.isEmpty())
+				return -1; // undefined if one of the two has no cities
+			return commonElementsPercentage(codes1, codes2);
+		}
+	}
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/CosineSimilarity.java

@@ -0,0 +1,47 @@
+
+package eu.dnetlib.pace.tree;
+
+import java.util.Map;
+
+import eu.dnetlib.pace.config.Config;
+import eu.dnetlib.pace.tree.support.AbstractComparator;
+import eu.dnetlib.pace.tree.support.ComparatorClass;
+
+@ComparatorClass("cosineSimilarity")
+public class CosineSimilarity extends AbstractComparator<double[]> {
+
+	Map<String, String> params;
+
+	public CosineSimilarity(Map<String, String> params) {
+		super(params);
+	}
+
+	@Override
+	public double compare(Object a, Object b, Config config) {
+		return compare((double[]) a, (double[]) b, config);
+	}
+
+	public double compare(final double[] a, final double[] b, final Config conf) {
+
+		if (a.length == 0 || b.length == 0)
+			return -1;
+
+		return cosineSimilarity(a, b);
+	}
+
+	double cosineSimilarity(double[] a, double[] b) {
+		double dotProduct = 0;
+		double normASum = 0;
+		double normBSum = 0;
+
+		for (int i = 0; i < a.length; i++) {
+			dotProduct += a[i] * b[i];
+			normASum += a[i] * a[i];
+			normBSum += b[i] * b[i];
+		}
+
+		double eucledianDist = Math.sqrt(normASum) * Math.sqrt(normBSum);
+		return dotProduct / eucledianDist;
+	}
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/DoiExactMatch.java

@@ -0,0 +1,27 @@
+
+package eu.dnetlib.pace.tree;
+
+import java.util.Map;
+
+import eu.dnetlib.pace.tree.support.ComparatorClass;
+
+/**
+ * The Class ExactMatch.
+ *
+ * @author claudio
+ */
+@ComparatorClass("doiExactMatch")
+public class DoiExactMatch extends ExactMatchIgnoreCase {
+
+	public final String PREFIX = "(http:\\/\\/dx\\.doi\\.org\\/)|(doi:)";
+
+	public DoiExactMatch(final Map<String, String> params) {
+		super(params);
+	}
+
+	@Override
+	protected String toString(final Object f) {
+		return super.toString(f).replaceAll(PREFIX, "");
+	}
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/DomainExactMatch.java

@@ -0,0 +1,30 @@
+
+package eu.dnetlib.pace.tree;
+
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.util.Map;
+
+import eu.dnetlib.pace.tree.support.ComparatorClass;
+
+@ComparatorClass("domainExactMatch")
+public class DomainExactMatch extends ExactMatchIgnoreCase {
+
+	public DomainExactMatch(final Map<String, String> params) {
+		super(params);
+	}
+
+	@Override
+	protected String toString(final Object f) {
+
+		try {
+			return asUrl(super.toString(f)).getHost();
+		} catch (MalformedURLException e) {
+			return "";
+		}
+	}
+
+	private URL asUrl(final String value) throws MalformedURLException {
+		return new URL(value);
+	}
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/ExactMatch.java

@@ -0,0 +1,44 @@
+
+package eu.dnetlib.pace.tree;
+
+import java.util.Map;
+
+import com.wcohen.ss.AbstractStringDistance;
+
+import eu.dnetlib.pace.config.Config;
+import eu.dnetlib.pace.tree.support.AbstractStringComparator;
+import eu.dnetlib.pace.tree.support.ComparatorClass;
+
+@ComparatorClass("exactMatch")
+public class ExactMatch extends AbstractStringComparator {
+
+	public ExactMatch(Map<String, String> params) {
+		super(params, new com.wcohen.ss.JaroWinkler());
+	}
+
+	public ExactMatch(final double weight) {
+		super(weight, new com.wcohen.ss.JaroWinkler());
+	}
+
+	protected ExactMatch(final double weight, final AbstractStringDistance ssalgo) {
+		super(weight, ssalgo);
+	}
+
+	@Override
+	public double distance(final String a, final String b, final Config conf) {
+		if (a.isEmpty() || b.isEmpty()) {
+			return -1.0; // return -1 if a field is missing
+		}
+		return a.equals(b) ? 1.0 : 0;
+	}
+
+	@Override
+	public double getWeight() {
+		return super.weight;
+	}
+
+	@Override
+	protected double normalize(final double d) {
+		return d;
+	}
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/ExactMatchIgnoreCase.java

@@ -0,0 +1,29 @@
+
+package eu.dnetlib.pace.tree;
+
+import java.util.Map;
+
+import eu.dnetlib.pace.config.Config;
+import eu.dnetlib.pace.tree.support.AbstractStringComparator;
+import eu.dnetlib.pace.tree.support.ComparatorClass;
+
+@ComparatorClass("exactMatchIgnoreCase")
+public class ExactMatchIgnoreCase extends AbstractStringComparator {
+
+	public ExactMatchIgnoreCase(Map<String, String> params) {
+		super(params);
+	}
+
+	@Override
+	public double compare(String a, String b, final Config conf) {
+
+		if (a.isEmpty() || b.isEmpty())
+			return -1;
+
+		return a.equalsIgnoreCase(b) ? 1 : 0;
+	}
+
+	protected String toString(final Object object) {
+		return toFirstString(object);
+	}
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/InstanceTypeMatch.java

@@ -0,0 +1,80 @@
+
+package eu.dnetlib.pace.tree;
+
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+import com.google.common.collect.Sets;
+
+import eu.dnetlib.pace.config.Config;
+import eu.dnetlib.pace.tree.support.AbstractListComparator;
+import eu.dnetlib.pace.tree.support.ComparatorClass;
+
+@ComparatorClass("instanceTypeMatch")
+public class InstanceTypeMatch extends AbstractListComparator {
+
+	final Map<String, String> translationMap = new HashMap<>();
+
+	public InstanceTypeMatch(Map<String, String> params) {
+		super(params);
+
+		// jolly types
+		translationMap.put("Conference object", "*");
+		translationMap.put("Other literature type", "*");
+		translationMap.put("Unknown", "*");
+
+		// article types
+		translationMap.put("Article", "Article");
+		translationMap.put("Data Paper", "Article");
+		translationMap.put("Software Paper", "Article");
+		translationMap.put("Preprint", "Article");
+
+		// thesis types
+		translationMap.put("Thesis", "Thesis");
+		translationMap.put("Master thesis", "Thesis");
+		translationMap.put("Bachelor thesis", "Thesis");
+		translationMap.put("Doctoral thesis", "Thesis");
+	}
+
+	@Override
+	public double compare(final List<String> a, final List<String> b, final Config conf) {
+
+		if (a == null || b == null) {
+			return -1;
+		}
+
+		if (a.isEmpty() || b.isEmpty()) {
+			return -1;
+		}
+
+		final Set<String> ca = a.stream().map(this::translate).collect(Collectors.toSet());
+		final Set<String> cb = b.stream().map(this::translate).collect(Collectors.toSet());
+
+		// if at least one is a jolly type, it must produce a match
+		if (ca.contains("*") || cb.contains("*"))
+			return 1.0;
+
+		int incommon = Sets.intersection(ca, cb).size();
+
+		// if at least one is in common, it must produce a match
+		return incommon >= 1 ? 1 : 0;
+	}
+
+	public String translate(String term) {
+		return translationMap.getOrDefault(term, term);
+	}
+
+	@Override
+	public double getWeight() {
+		return super.weight;
+	}
+
+	@Override
+	protected double normalize(final double d) {
+		return d;
+	}
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/JaroWinkler.java

@@ -0,0 +1,46 @@
+
+package eu.dnetlib.pace.tree;
+
+import java.util.Map;
+
+import com.wcohen.ss.AbstractStringDistance;
+
+import eu.dnetlib.pace.config.Config;
+import eu.dnetlib.pace.tree.support.AbstractStringComparator;
+import eu.dnetlib.pace.tree.support.ComparatorClass;
+
+//case class JaroWinkler(w: Double) extends SecondStringDistanceAlgo(w, new com.wcohen.ss.JaroWinkler())
+@ComparatorClass("jaroWinkler")
+public class JaroWinkler extends AbstractStringComparator {
+
+	public JaroWinkler(Map<String, String> params) {
+		super(params, new com.wcohen.ss.JaroWinkler());
+	}
+
+	public JaroWinkler(double weight) {
+		super(weight, new com.wcohen.ss.JaroWinkler());
+	}
+
+	protected JaroWinkler(double weight, AbstractStringDistance ssalgo) {
+		super(weight, ssalgo);
+	}
+
+	@Override
+	public double distance(String a, String b, final Config conf) {
+		String ca = cleanup(a);
+		String cb = cleanup(b);
+
+		return normalize(ssalgo.score(ca, cb));
+	}
+
+	@Override
+	public double getWeight() {
+		return super.weight;
+	}
+
+	@Override
+	protected double normalize(double d) {
+		return d;
+	}
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/JaroWinklerNormalizedName.java

@@ -0,0 +1,74 @@
+
+package eu.dnetlib.pace.tree;
+
+import java.util.Map;
+import java.util.Set;
+
+import com.wcohen.ss.AbstractStringDistance;
+
+import eu.dnetlib.pace.config.Config;
+import eu.dnetlib.pace.tree.support.AbstractStringComparator;
+import eu.dnetlib.pace.tree.support.ComparatorClass;
+
+@ComparatorClass("jaroWinklerNormalizedName")
+public class JaroWinklerNormalizedName extends AbstractStringComparator {
+
+	private Map<String, String> params;
+
+	public JaroWinklerNormalizedName(Map<String, String> params) {
+		super(params, new com.wcohen.ss.JaroWinkler());
+		this.params = params;
+	}
+
+	public JaroWinklerNormalizedName(double weight) {
+		super(weight, new com.wcohen.ss.JaroWinkler());
+	}
+
+	protected JaroWinklerNormalizedName(double weight, AbstractStringDistance ssalgo) {
+		super(weight, ssalgo);
+	}
+
+	@Override
+	public double distance(String a, String b, final Config conf) {
+		String ca = cleanup(a);
+		String cb = cleanup(b);
+
+		ca = normalize(ca);
+		cb = normalize(cb);
+
+		ca = filterAllStopWords(ca);
+		cb = filterAllStopWords(cb);
+
+		Set<String> keywords1 = getKeywords(
+			ca, conf.translationMap(), Integer.parseInt(params.getOrDefault("windowSize", "4")));
+		Set<String> keywords2 = getKeywords(
+			cb, conf.translationMap(), Integer.parseInt(params.getOrDefault("windowSize", "4")));
+
+		Set<String> cities1 = getCities(ca, Integer.parseInt(params.getOrDefault("windowSize", "4")));
+		Set<String> cities2 = getCities(cb, Integer.parseInt(params.getOrDefault("windowSize", "4")));
+
+		ca = removeKeywords(ca, keywords1);
+		ca = removeKeywords(ca, cities1);
+		cb = removeKeywords(cb, keywords2);
+		cb = removeKeywords(cb, cities2);
+
+		ca = ca.replaceAll("[ ]{2,}", " ");
+		cb = cb.replaceAll("[ ]{2,}", " ");
+
+		if (ca.isEmpty() && cb.isEmpty())
+			return 1.0;
+		else
+			return normalize(ssalgo.score(ca, cb));
+	}
+
+	@Override
+	public double getWeight() {
+		return super.weight;
+	}
+
+	@Override
+	protected double normalize(double d) {
+		return d;
+	}
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/JaroWinklerTitle.java

@@ -0,0 +1,47 @@
+
+package eu.dnetlib.pace.tree;
+
+import java.util.Map;
+
+import com.wcohen.ss.AbstractStringDistance;
+
+import eu.dnetlib.pace.config.Config;
+import eu.dnetlib.pace.tree.support.AbstractStringComparator;
+import eu.dnetlib.pace.tree.support.ComparatorClass;
+
+//case class JaroWinkler(w: Double) extends SecondStringDistanceAlgo(w, new com.wcohen.ss.JaroWinkler())
+@ComparatorClass("jaroWinklerTitle")
+public class JaroWinklerTitle extends AbstractStringComparator {
+
+	public JaroWinklerTitle(Map<String, String> params) {
+		super(params, new com.wcohen.ss.JaroWinkler());
+	}
+
+	public JaroWinklerTitle(double weight) {
+		super(weight, new com.wcohen.ss.JaroWinkler());
+	}
+
+	protected JaroWinklerTitle(double weight, AbstractStringDistance ssalgo) {
+		super(weight, ssalgo);
+	}
+
+	@Override
+	public double distance(String a, String b, final Config conf) {
+		String ca = cleanup(a);
+		String cb = cleanup(b);
+
+		boolean check = checkNumbers(ca, cb);
+		return check ? 0.5 : normalize(ssalgo.score(ca, cb));
+	}
+
+	@Override
+	public double getWeight() {
+		return super.weight;
+	}
+
+	@Override
+	protected double normalize(double d) {
+		return d;
+	}
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/JsonListMatch.java

@@ -0,0 +1,82 @@
+
+package eu.dnetlib.pace.tree;
+
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
+import com.google.common.collect.Sets;
+import com.jayway.jsonpath.Configuration;
+import com.jayway.jsonpath.DocumentContext;
+import com.jayway.jsonpath.JsonPath;
+import com.jayway.jsonpath.Option;
+
+import eu.dnetlib.pace.config.Config;
+import eu.dnetlib.pace.tree.support.AbstractListComparator;
+import eu.dnetlib.pace.tree.support.ComparatorClass;
+import eu.dnetlib.pace.util.MapDocumentUtil;
+
+@ComparatorClass("jsonListMatch")
+public class JsonListMatch extends AbstractListComparator {
+
+	private static final Log log = LogFactory.getLog(JsonListMatch.class);
+	private Map<String, String> params;
+
+	private String MODE; // "percentage" or "count"
+
+	public JsonListMatch(final Map<String, String> params) {
+		super(params);
+		this.params = params;
+
+		MODE = params.getOrDefault("mode", "percentage");
+	}
+
+	@Override
+	public double compare(final List<String> sa, final List<String> sb, final Config conf) {
+		if (sa.isEmpty() || sb.isEmpty()) {
+			return -1;
+		}
+
+		final Set<String> ca = sa.stream().map(this::toComparableString).collect(Collectors.toSet());
+		final Set<String> cb = sb.stream().map(this::toComparableString).collect(Collectors.toSet());
+
+		int incommon = Sets.intersection(ca, cb).size();
+		int simDiff = Sets.symmetricDifference(ca, cb).size();
+
+		if (incommon + simDiff == 0) {
+			return 0.0;
+		}
+
+		if (MODE.equals("percentage"))
+			return (double) incommon / (incommon + simDiff);
+		else
+			return incommon;
+
+	}
+
+	// converts every json into a comparable string basing on parameters
+	private String toComparableString(String json) {
+
+		StringBuilder st = new StringBuilder(); // to build the string used for comparisons basing on the jpath into
+												// parameters
+		final DocumentContext documentContext = JsonPath
+			.using(Configuration.defaultConfiguration().addOptions(Option.SUPPRESS_EXCEPTIONS))
+			.parse(json);
+		// for each path in the param list
+		for (String key : params.keySet().stream().filter(k -> k.contains("jpath")).collect(Collectors.toList())) {
+			String path = params.get(key);
+			String value = MapDocumentUtil.getJPathString(path, documentContext);
+			if (value == null || value.isEmpty())
+				value = "";
+			st.append(value);
+			st.append("::");
+		}
+
+		st.setLength(st.length() - 2);
+		return st.toString();
+	}
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/KeywordMatch.java

@@ -0,0 +1,50 @@
+
+package eu.dnetlib.pace.tree;
+
+import java.util.Map;
+import java.util.Set;
+
+import eu.dnetlib.pace.config.Config;
+import eu.dnetlib.pace.tree.support.AbstractStringComparator;
+import eu.dnetlib.pace.tree.support.ComparatorClass;
+
+@ComparatorClass("keywordMatch")
+public class KeywordMatch extends AbstractStringComparator {
+
+	Map<String, String> params;
+
+	public KeywordMatch(Map<String, String> params) {
+		super(params);
+		this.params = params;
+	}
+
+	@Override
+	public double distance(final String a, final String b, final Config conf) {
+
+		String ca = cleanup(a);
+		String cb = cleanup(b);
+
+		ca = normalize(ca);
+		cb = normalize(cb);
+
+		ca = filterAllStopWords(ca);
+		cb = filterAllStopWords(cb);
+
+		Set<String> keywords1 = getKeywords(
+			ca, conf.translationMap(), Integer.parseInt(params.getOrDefault("windowSize", "4")));
+		Set<String> keywords2 = getKeywords(
+			cb, conf.translationMap(), Integer.parseInt(params.getOrDefault("windowSize", "4")));
+
+		Set<String> codes1 = toCodes(keywords1, conf.translationMap());
+		Set<String> codes2 = toCodes(keywords2, conf.translationMap());
+
+		// if no cities are detected, the comparator gives 1.0
+		if (codes1.isEmpty() && codes2.isEmpty())
+			return 1.0;
+		else {
+			if (codes1.isEmpty() ^ codes2.isEmpty())
+				return -1.0; // undefined if one of the two has no keywords
+			return commonElementsPercentage(codes1, codes2);
+		}
+	}
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/Level2JaroWinkler.java

@@ -0,0 +1,36 @@
+
+package eu.dnetlib.pace.tree;
+
+import java.util.Map;
+
+import com.wcohen.ss.AbstractStringDistance;
+
+import eu.dnetlib.pace.tree.support.AbstractStringComparator;
+import eu.dnetlib.pace.tree.support.ComparatorClass;
+
+@ComparatorClass("level2JaroWinkler")
+public class Level2JaroWinkler extends AbstractStringComparator {
+
+	public Level2JaroWinkler(Map<String, String> params) {
+		super(params, new com.wcohen.ss.Level2JaroWinkler());
+	}
+
+	public Level2JaroWinkler(double w) {
+		super(w, new com.wcohen.ss.Level2JaroWinkler());
+	}
+
+	protected Level2JaroWinkler(double w, AbstractStringDistance ssalgo) {
+		super(w, ssalgo);
+	}
+
+	@Override
+	public double getWeight() {
+		return super.weight;
+	}
+
+	@Override
+	protected double normalize(double d) {
+		return d;
+	}
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/Level2JaroWinklerTitle.java

@@ -0,0 +1,50 @@
+
+package eu.dnetlib.pace.tree;
+
+import java.util.Map;
+
+import com.wcohen.ss.AbstractStringDistance;
+
+import eu.dnetlib.pace.config.Config;
+import eu.dnetlib.pace.tree.support.AbstractStringComparator;
+import eu.dnetlib.pace.tree.support.ComparatorClass;
+
+@ComparatorClass("level2JaroWinklerTitle")
+public class Level2JaroWinklerTitle extends AbstractStringComparator {
+
+	public Level2JaroWinklerTitle(Map<String, String> params) {
+		super(params, new com.wcohen.ss.Level2JaroWinkler());
+	}
+
+	public Level2JaroWinklerTitle(final double w) {
+		super(w, new com.wcohen.ss.Level2JaroWinkler());
+	}
+
+	protected Level2JaroWinklerTitle(final double w, final AbstractStringDistance ssalgo) {
+		super(w, ssalgo);
+	}
+
+	@Override
+	public double distance(final String a, final String b, final Config conf) {
+		final String ca = cleanup(a);
+		final String cb = cleanup(b);
+
+		final boolean check = checkNumbers(ca, cb);
+
+		if (check)
+			return 0.5;
+
+		return ssalgo.score(ca, cb);
+	}
+
+	@Override
+	public double getWeight() {
+		return super.weight;
+	}
+
+	@Override
+	protected double normalize(final double d) {
+		return d;
+	}
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/Level2Levenstein.java

@@ -0,0 +1,36 @@
+
+package eu.dnetlib.pace.tree;
+
+import java.util.Map;
+
+import com.wcohen.ss.AbstractStringDistance;
+
+import eu.dnetlib.pace.tree.support.AbstractStringComparator;
+import eu.dnetlib.pace.tree.support.ComparatorClass;
+
+@ComparatorClass("level2Levenstein")
+public class Level2Levenstein extends AbstractStringComparator {
+
+	public Level2Levenstein(Map<String, String> params) {
+		super(params, new com.wcohen.ss.Level2Levenstein());
+	}
+
+	public Level2Levenstein(double w) {
+		super(w, new com.wcohen.ss.Level2Levenstein());
+	}
+
+	protected Level2Levenstein(double w, AbstractStringDistance ssalgo) {
+		super(w, ssalgo);
+	}
+
+	@Override
+	public double getWeight() {
+		return super.weight;
+	}
+
+	@Override
+	protected double normalize(double d) {
+		return 1 / Math.pow(Math.abs(d) + 1, 0.1);
+	}
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/Levenstein.java

@@ -0,0 +1,36 @@
+
+package eu.dnetlib.pace.tree;
+
+import java.util.Map;
+
+import com.wcohen.ss.AbstractStringDistance;
+
+import eu.dnetlib.pace.tree.support.AbstractStringComparator;
+import eu.dnetlib.pace.tree.support.ComparatorClass;
+
+@ComparatorClass("levenstein")
+public class Levenstein extends AbstractStringComparator {
+
+	public Levenstein(Map<String, String> params) {
+		super(params, new com.wcohen.ss.Levenstein());
+	}
+
+	public Levenstein(double w) {
+		super(w, new com.wcohen.ss.Levenstein());
+	}
+
+	protected Levenstein(double w, AbstractStringDistance ssalgo) {
+		super(w, ssalgo);
+	}
+
+	@Override
+	public double getWeight() {
+		return super.weight;
+	}
+
+	@Override
+	protected double normalize(double d) {
+		return 1 / Math.pow(Math.abs(d) + 1, 0.1);
+	}
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/LevensteinTitle.java

@@ -0,0 +1,59 @@
+
+package eu.dnetlib.pace.tree;
+
+import java.util.Map;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
+import com.wcohen.ss.AbstractStringDistance;
+
+import eu.dnetlib.pace.config.Config;
+import eu.dnetlib.pace.tree.support.AbstractStringComparator;
+import eu.dnetlib.pace.tree.support.ComparatorClass;
+
+@ComparatorClass("levensteinTitle")
+public class LevensteinTitle extends AbstractStringComparator {
+
+	private static final Log log = LogFactory.getLog(LevensteinTitle.class);
+
+	public LevensteinTitle(Map<String, String> params) {
+		super(params, new com.wcohen.ss.Levenstein());
+	}
+
+	public LevensteinTitle(final double w) {
+		super(w, new com.wcohen.ss.Levenstein());
+	}
+
+	protected LevensteinTitle(final double w, final AbstractStringDistance ssalgo) {
+		super(w, ssalgo);
+	}
+
+	@Override
+	public double distance(final String a, final String b, final Config conf) {
+		final String ca = cleanup(a);
+		final String cb = cleanup(b);
+
+		final boolean check = checkNumbers(ca, cb);
+
+		if (check)
+			return 0.5;
+
+		return normalize(ssalgo.score(ca, cb), ca.length(), cb.length());
+	}
+
+	private double normalize(final double score, final int la, final int lb) {
+		return 1 - (Math.abs(score) / Math.max(la, lb));
+	}
+
+	@Override
+	public double getWeight() {
+		return super.weight;
+	}
+
+	@Override
+	protected double normalize(final double d) {
+		return 1 / Math.pow(Math.abs(d) + 1, 0.1);
+	}
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/LevensteinTitleIgnoreVersion.java

@@ -0,0 +1,58 @@
+
+package eu.dnetlib.pace.tree;
+
+import java.util.Map;
+
+import com.wcohen.ss.AbstractStringDistance;
+
+import eu.dnetlib.pace.config.Config;
+import eu.dnetlib.pace.tree.support.AbstractStringComparator;
+import eu.dnetlib.pace.tree.support.ComparatorClass;
+
+/**
+ * Compared compare between two titles, ignoring version numbers. Suitable for Software entities.
+ */
+@ComparatorClass("levensteinTitleIgnoreVersion")
+public class LevensteinTitleIgnoreVersion extends AbstractStringComparator {
+
+	public LevensteinTitleIgnoreVersion(Map<String, String> params) {
+		super(params, new com.wcohen.ss.Levenstein());
+	}
+
+	public LevensteinTitleIgnoreVersion(final double w) {
+		super(w, new com.wcohen.ss.Levenstein());
+	}
+
+	protected LevensteinTitleIgnoreVersion(final double w, final AbstractStringDistance ssalgo) {
+		super(w, ssalgo);
+	}
+
+	@Override
+	public double distance(final String a, final String b, final Config conf) {
+		String ca = cleanup(a);
+		String cb = cleanup(b);
+
+		ca = ca.replaceAll("\\d", "").replaceAll(getRomans(ca), "").trim();
+		cb = cb.replaceAll("\\d", "").replaceAll(getRomans(cb), "").trim();
+
+		ca = filterAllStopWords(ca);
+		cb = filterAllStopWords(cb);
+
+		return normalize(ssalgo.score(ca, cb), ca.length(), cb.length());
+	}
+
+	private double normalize(final double score, final int la, final int lb) {
+		return 1 - (Math.abs(score) / Math.max(la, lb));
+	}
+
+	@Override
+	public double getWeight() {
+		return super.weight;
+	}
+
+	@Override
+	protected double normalize(final double d) {
+		return 1 / Math.pow(Math.abs(d) + 1, 0.1);
+	}
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/ListContainsMatch.java

@@ -0,0 +1,66 @@
+
+package eu.dnetlib.pace.tree;
+
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+import eu.dnetlib.pace.config.Config;
+import eu.dnetlib.pace.tree.support.AbstractListComparator;
+import eu.dnetlib.pace.tree.support.ComparatorClass;
+
+/**
+ * The Class Contains match
+ *
+ * @author miconis
+ * */
+@ComparatorClass("listContainsMatch")
+public class ListContainsMatch extends AbstractListComparator {
+
+	private Map<String, String> params;
+	private boolean CASE_SENSITIVE;
+	private String STRING;
+	private String AGGREGATOR;
+
+	public ListContainsMatch(Map<String, String> params) {
+		super(params);
+		this.params = params;
+
+		// read parameters
+		CASE_SENSITIVE = Boolean.parseBoolean(params.getOrDefault("caseSensitive", "false"));
+		STRING = params.get("string");
+		AGGREGATOR = params.get("bool");
+	}
+
+	@Override
+	public double compare(List<String> sa, List<String> sb, Config conf) {
+		if (sa.isEmpty() || sb.isEmpty()) {
+			return -1;
+		}
+
+		if (!CASE_SENSITIVE) {
+			sa = sa.stream().map(String::toLowerCase).collect(Collectors.toList());
+			sb = sb.stream().map(String::toLowerCase).collect(Collectors.toList());
+			STRING = STRING.toLowerCase();
+		}
+
+		switch (AGGREGATOR) {
+			case "AND":
+				if (sa.contains(STRING) && sb.contains(STRING))
+					return 1.0;
+				break;
+			case "OR":
+				if (sa.contains(STRING) || sb.contains(STRING))
+					return 1.0;
+				break;
+			case "XOR":
+				if (sa.contains(STRING) ^ sb.contains(STRING))
+					return 1.0;
+				break;
+			default:
+				return 0.0;
+		}
+		return 0.0;
+
+	}
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/MustBeDifferent.java

@@ -0,0 +1,42 @@
+
+package eu.dnetlib.pace.tree;
+
+import java.util.Map;
+
+import com.wcohen.ss.AbstractStringDistance;
+
+import eu.dnetlib.pace.config.Config;
+import eu.dnetlib.pace.tree.support.AbstractStringComparator;
+import eu.dnetlib.pace.tree.support.ComparatorClass;
+
+@ComparatorClass("mustBeDifferent")
+public class MustBeDifferent extends AbstractStringComparator {
+
+	public MustBeDifferent(Map<String, String> params) {
+		super(params, new com.wcohen.ss.Levenstein());
+	}
+
+	public MustBeDifferent(final double weight) {
+		super(weight, new com.wcohen.ss.JaroWinkler());
+	}
+
+	protected MustBeDifferent(final double weight, final AbstractStringDistance ssalgo) {
+		super(weight, ssalgo);
+	}
+
+	@Override
+	public double distance(final String a, final String b, final Config conf) {
+		return !a.equals(b) ? 1.0 : 0;
+	}
+
+	@Override
+	public double getWeight() {
+		return super.weight;
+	}
+
+	@Override
+	protected double normalize(final double d) {
+		return d;
+	}
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/NullDistanceAlgo.java

@@ -0,0 +1,24 @@
+
+package eu.dnetlib.pace.tree;
+
+import java.util.Map;
+
+import eu.dnetlib.pace.config.Config;
+import eu.dnetlib.pace.tree.support.Comparator;
+import eu.dnetlib.pace.tree.support.ComparatorClass;
+
+/**
+ * Not all fields of a document need to partecipate in the compare measure. We model those fields as having a
+ * NullDistanceAlgo.
+ */
+@ComparatorClass("null")
+public class NullDistanceAlgo<T> implements Comparator<T> {
+
+	public NullDistanceAlgo(Map<String, String> params) {
+	}
+
+	@Override
+	public double compare(Object a, Object b, Config config) {
+		return 0;
+	}
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/NumbersComparator.java

@@ -0,0 +1,35 @@
+
+package eu.dnetlib.pace.tree;
+
+import java.util.Map;
+
+import eu.dnetlib.pace.config.Config;
+import eu.dnetlib.pace.tree.support.AbstractStringComparator;
+import eu.dnetlib.pace.tree.support.ComparatorClass;
+
+@ComparatorClass("numbersComparator")
+public class NumbersComparator extends AbstractStringComparator {
+
+	Map<String, String> params;
+
+	public NumbersComparator(Map<String, String> params) {
+		super(params);
+		this.params = params;
+	}
+
+	@Override
+	public double distance(String a, String b, Config conf) {
+
+		// extracts numbers from the field
+		String numbers1 = getNumbers(nfd(a));
+		String numbers2 = getNumbers(nfd(b));
+
+		if (numbers1.isEmpty() || numbers2.isEmpty())
+			return -1.0;
+
+		int n1 = Integer.parseInt(numbers1);
+		int n2 = Integer.parseInt(numbers2);
+
+		return Math.abs(n1 - n2);
+	}
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/NumbersMatch.java

@@ -0,0 +1,35 @@
+
+package eu.dnetlib.pace.tree;
+
+import java.util.Map;
+
+import eu.dnetlib.pace.config.Config;
+import eu.dnetlib.pace.tree.support.AbstractStringComparator;
+import eu.dnetlib.pace.tree.support.ComparatorClass;
+
+@ComparatorClass("numbersMatch")
+public class NumbersMatch extends AbstractStringComparator {
+
+	public NumbersMatch(Map<String, String> params) {
+		super(params);
+	}
+
+	@Override
+	public double distance(String a, String b, Config conf) {
+
+		// extracts numbers from the field
+		String numbers1 = getNumbers(nfd(a));
+		String numbers2 = getNumbers(nfd(b));
+
+		if (numbers1.isEmpty() && numbers2.isEmpty())
+			return 1.0;
+
+		if (numbers1.isEmpty() || numbers2.isEmpty())
+			return -1.0;
+
+		if (numbers1.equals(numbers2))
+			return 1.0;
+
+		return 0.0;
+	}
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/RomansMatch.java

@@ -0,0 +1,35 @@
+
+package eu.dnetlib.pace.tree;
+
+import java.util.Map;
+
+import eu.dnetlib.pace.config.Config;
+import eu.dnetlib.pace.tree.support.AbstractStringComparator;
+import eu.dnetlib.pace.tree.support.ComparatorClass;
+
+@ComparatorClass("romansMatch")
+public class RomansMatch extends AbstractStringComparator {
+
+	public RomansMatch(Map<String, String> params) {
+		super(params);
+	}
+
+	@Override
+	public double distance(String a, String b, Config conf) {
+
+		// extracts romans from the field
+		String romans1 = getRomans(nfd(a));
+		String romans2 = getRomans(nfd(b));
+
+		if (romans1.isEmpty() && romans2.isEmpty())
+			return 1.0;
+
+		if (romans1.isEmpty() || romans2.isEmpty())
+			return -1.0;
+
+		if (romans1.equals(romans2))
+			return 1.0;
+
+		return 0.0;
+	}
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/SizeMatch.java

@@ -0,0 +1,38 @@
+
+package eu.dnetlib.pace.tree;
+
+import java.util.List;
+import java.util.Map;
+
+import eu.dnetlib.pace.config.Config;
+import eu.dnetlib.pace.tree.support.AbstractListComparator;
+import eu.dnetlib.pace.tree.support.ComparatorClass;
+
+/**
+ * Returns true if the number of values in the fields is the same.
+ *
+ * @author claudio
+ */
+@ComparatorClass("sizeMatch")
+public class SizeMatch extends AbstractListComparator {
+
+	/**
+	 * Instantiates a new size match.
+	 *
+	 * @param params
+	 *            the parameters
+	 */
+	public SizeMatch(final Map<String, String> params) {
+		super(params);
+	}
+
+	@Override
+	public double compare(final List<String> a, final List<String> b, final Config conf) {
+
+		if (a.isEmpty() || b.isEmpty())
+			return -1.0;
+
+		return a.size() == b.size() ? 1.0 : 0.0;
+	}
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/SortedJaroWinkler.java

@@ -0,0 +1,61 @@
+
+package eu.dnetlib.pace.tree;
+
+import java.util.Map;
+
+import com.wcohen.ss.AbstractStringDistance;
+
+import eu.dnetlib.pace.tree.support.AbstractSortedComparator;
+import eu.dnetlib.pace.tree.support.ComparatorClass;
+
+/**
+ * The Class SortedJaroWinkler.
+ */
+@ComparatorClass("sortedJaroWinkler")
+public class SortedJaroWinkler extends AbstractSortedComparator {
+
+	public SortedJaroWinkler(Map<String, String> params) {
+		super(params, new com.wcohen.ss.Levenstein());
+	}
+
+	/**
+	 * Instantiates a new sorted jaro winkler.
+	 * 
+	 * @param weight
+	 *            the weight
+	 */
+	public SortedJaroWinkler(final double weight) {
+		super(weight, new com.wcohen.ss.JaroWinkler());
+	}
+
+	/**
+	 * Instantiates a new sorted jaro winkler.
+	 * 
+	 * @param weight
+	 *            the weight
+	 * @param ssalgo
+	 *            the ssalgo
+	 */
+	protected SortedJaroWinkler(final double weight, final AbstractStringDistance ssalgo) {
+		super(weight, ssalgo);
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see eu.dnetlib.pace.compare.DistanceAlgo#getWeight()
+	 */
+	@Override
+	public double getWeight() {
+		return super.weight;
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see eu.dnetlib.pace.compare.SecondStringDistanceAlgo#normalize(double)
+	 */
+	@Override
+	protected double normalize(final double d) {
+		return d;
+	}
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/SortedLevel2JaroWinkler.java

@@ -0,0 +1,61 @@
+
+package eu.dnetlib.pace.tree;
+
+import java.util.Map;
+
+import com.wcohen.ss.AbstractStringDistance;
+
+import eu.dnetlib.pace.tree.support.AbstractSortedComparator;
+import eu.dnetlib.pace.tree.support.ComparatorClass;
+
+/**
+ * The Class SortedJaroWinkler.
+ */
+@ComparatorClass("sortedLevel2JaroWinkler")
+public class SortedLevel2JaroWinkler extends AbstractSortedComparator {
+
+	/**
+	 * Instantiates a new sorted jaro winkler.
+	 * 
+	 * @param weight
+	 *            the weight
+	 */
+	public SortedLevel2JaroWinkler(final double weight) {
+		super(weight, new com.wcohen.ss.Level2JaroWinkler());
+	}
+
+	public SortedLevel2JaroWinkler(final Map<String, String> params) {
+		super(params, new com.wcohen.ss.Level2JaroWinkler());
+	}
+
+	/**
+	 * Instantiates a new sorted jaro winkler.
+	 * 
+	 * @param weight
+	 *            the weight
+	 * @param ssalgo
+	 *            the ssalgo
+	 */
+	protected SortedLevel2JaroWinkler(final double weight, final AbstractStringDistance ssalgo) {
+		super(weight, ssalgo);
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see eu.dnetlib.pace.compare.DistanceAlgo#getWeight()
+	 */
+	@Override
+	public double getWeight() {
+		return super.weight;
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see eu.dnetlib.pace.compare.SecondStringDistanceAlgo#normalize(double)
+	 */
+	@Override
+	protected double normalize(final double d) {
+		return d;
+	}
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/StringContainsMatch.java

@@ -0,0 +1,67 @@
+
+package eu.dnetlib.pace.tree;
+
+import java.util.Map;
+
+import eu.dnetlib.pace.config.Config;
+import eu.dnetlib.pace.tree.support.AbstractStringComparator;
+import eu.dnetlib.pace.tree.support.ComparatorClass;
+
+/**
+ * The Class Contains match
+ *
+ * @author miconis
+ * */
+@ComparatorClass("stringContainsMatch")
+public class StringContainsMatch extends AbstractStringComparator {
+
+	private Map<String, String> params;
+
+	private boolean CASE_SENSITIVE;
+	private String STRING;
+	private String AGGREGATOR;
+
+	public StringContainsMatch(Map<String, String> params) {
+		super(params);
+		this.params = params;
+
+		// read parameters
+		CASE_SENSITIVE = Boolean.parseBoolean(params.getOrDefault("caseSensitive", "false"));
+		STRING = params.get("string");
+		AGGREGATOR = params.get("aggregator");
+
+	}
+
+	@Override
+	public double distance(final String a, final String b, final Config conf) {
+
+		String ca = a;
+		String cb = b;
+		if (!CASE_SENSITIVE) {
+			ca = a.toLowerCase();
+			cb = b.toLowerCase();
+			STRING = STRING.toLowerCase();
+		}
+
+		if (AGGREGATOR != null) {
+			switch (AGGREGATOR) {
+				case "AND":
+					if (ca.contains(STRING) && cb.contains(STRING))
+						return 1.0;
+					break;
+				case "OR":
+					if (ca.contains(STRING) || cb.contains(STRING))
+						return 1.0;
+					break;
+				case "XOR":
+					if (ca.contains(STRING) ^ cb.contains(STRING))
+						return 1.0;
+					break;
+				default:
+					return 0.0;
+			}
+		}
+
+		return 0.0;
+	}
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/StringListMatch.java

@@ -0,0 +1,56 @@
+
+package eu.dnetlib.pace.tree;
+
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
+import com.google.common.collect.Sets;
+
+import eu.dnetlib.pace.config.Config;
+import eu.dnetlib.pace.tree.support.AbstractListComparator;
+import eu.dnetlib.pace.tree.support.ComparatorClass;
+
+@ComparatorClass("stringListMatch")
+public class StringListMatch extends AbstractListComparator {
+
+	private static final Log log = LogFactory.getLog(StringListMatch.class);
+	private Map<String, String> params;
+
+	final private String TYPE; // percentage or count
+
+	public StringListMatch(final Map<String, String> params) {
+		super(params);
+		this.params = params;
+
+		TYPE = params.getOrDefault("type", "percentage");
+	}
+
+	@Override
+	public double compare(final List<String> a, final List<String> b, final Config conf) {
+
+		final Set<String> pa = new HashSet<>(a);
+		final Set<String> pb = new HashSet<>(b);
+
+		if (pa.isEmpty() || pb.isEmpty()) {
+			return -1; // return undefined if one of the two lists is empty
+		}
+
+		int incommon = Sets.intersection(pa, pb).size();
+		int simDiff = Sets.symmetricDifference(pa, pb).size();
+
+		if (incommon + simDiff == 0) {
+			return 0.0;
+		}
+
+		if (TYPE.equals("percentage"))
+			return (double) incommon / (incommon + simDiff);
+		else
+			return incommon;
+
+	}
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/SubStringLevenstein.java

@@ -0,0 +1,90 @@
+
+package eu.dnetlib.pace.tree;
+
+import java.util.Map;
+
+import org.apache.commons.lang3.StringUtils;
+
+import com.wcohen.ss.AbstractStringDistance;
+
+import eu.dnetlib.pace.config.Config;
+import eu.dnetlib.pace.tree.support.AbstractStringComparator;
+import eu.dnetlib.pace.tree.support.ComparatorClass;
+
+/**
+ * The Class SubStringLevenstein.
+ */
+@ComparatorClass("subStringLevenstein")
+public class SubStringLevenstein extends AbstractStringComparator {
+
+	/**
+	 * The limit.
+	 */
+	protected int limit;
+
+	/**
+	 * Instantiates a new sub string levenstein.
+	 *
+	 * @param w the w
+	 */
+	public SubStringLevenstein(final double w) {
+		super(w, new com.wcohen.ss.Levenstein());
+	}
+
+	public SubStringLevenstein(Map<String, String> params) {
+		super(params, new com.wcohen.ss.Levenstein());
+		this.limit = Integer.parseInt(params.getOrDefault("limit", "1"));
+	}
+
+	/**
+	 * Instantiates a new sub string levenstein.
+	 *
+	 * @param w     the w
+	 * @param limit the limit
+	 */
+	public SubStringLevenstein(final double w, final int limit) {
+		super(w, new com.wcohen.ss.Levenstein());
+		this.limit = limit;
+	}
+
+	/**
+	 * Instantiates a new sub string levenstein.
+	 *
+	 * @param w      the w
+	 * @param limit  the limit
+	 * @param ssalgo the ssalgo
+	 */
+	protected SubStringLevenstein(final double w, final int limit, final AbstractStringDistance ssalgo) {
+		super(w, ssalgo);
+		this.limit = limit;
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see eu.dnetlib.pace.compare.SecondStringDistanceAlgo#compare(eu.dnetlib.pace.model.Field,
+	 * eu.dnetlib.pace.model.Field)
+	 */
+	@Override
+	public double distance(final String a, final String b, final Config conf) {
+		return distance(StringUtils.left(a, limit), StringUtils.left(b, limit), conf);
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see eu.dnetlib.pace.compare.DistanceAlgo#getWeight()
+	 */
+	@Override
+	public double getWeight() {
+		return super.weight;
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see eu.dnetlib.pace.compare.SecondStringDistanceAlgo#normalize(double)
+	 */
+	@Override
+	protected double normalize(final double d) {
+		return 1 / Math.pow(Math.abs(d) + 1, 0.1);
+	}
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/TitleVersionMatch.java

@@ -0,0 +1,39 @@
+
+package eu.dnetlib.pace.tree;
+
+import java.util.Map;
+
+import eu.dnetlib.pace.config.Config;
+import eu.dnetlib.pace.tree.support.AbstractStringComparator;
+import eu.dnetlib.pace.tree.support.ComparatorClass;
+
+/**
+ * Returns true if the titles in the given documents contains the same numbers, false otherwise.
+ *
+ * @author claudio
+ *
+ */
+@ComparatorClass("titleVersionMatch")
+public class TitleVersionMatch extends AbstractStringComparator {
+
+	public TitleVersionMatch(final Map<String, String> params) {
+		super(params);
+	}
+
+	@Override
+	public double compare(final String valueA, final String valueB, final Config conf) {
+		if (valueA.isEmpty() || valueB.isEmpty())
+			return -1;
+
+		return notNull(valueA) && notNull(valueB) && !checkNumbers(valueA, valueB) ? 1 : 0;
+	}
+
+	@Override
+	public String toString() {
+		return getClass().getSimpleName() + ":" + super.toString();
+	}
+
+	protected String toString(final Object object) {
+		return toFirstString(object);
+	}
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/UrlMatcher.java

@@ -0,0 +1,63 @@
+
+package eu.dnetlib.pace.tree;
+
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.util.Map;
+
+import org.apache.commons.lang3.StringUtils;
+
+import eu.dnetlib.pace.config.Config;
+import eu.dnetlib.pace.tree.support.ComparatorClass;
+
+@ComparatorClass("urlMatcher")
+public class UrlMatcher extends Levenstein {
+
+	private Map<String, String> params;
+
+	public UrlMatcher(Map<String, String> params) {
+		super(params);
+		this.params = params;
+	}
+
+	public UrlMatcher(double weight, Map<String, String> params) {
+		super(weight);
+		this.params = params;
+	}
+
+	public void setParams(Map<String, String> params) {
+		this.params = params;
+	}
+
+	@Override
+	public double distance(String a, String b, final Config conf) {
+		final URL urlA = asUrl(a);
+		final URL urlB = asUrl(b);
+
+		if (!urlA.getHost().equalsIgnoreCase(urlB.getHost())) {
+			return 0.0;
+		}
+
+		Double hostW = Double.parseDouble(params.getOrDefault("host", "0.5"));
+		Double pathW = Double.parseDouble(params.getOrDefault("path", "0.5"));
+
+		if (StringUtils.isBlank(urlA.getPath()) || StringUtils.isBlank(urlB.getPath())) {
+			return hostW * 0.5;
+		}
+
+		return hostW + pathW * super.distance(urlA.getPath(), urlB.getPath(), conf);
+	}
+
+	private URL asUrl(final String value) {
+		try {
+			return new URL(value);
+		} catch (MalformedURLException e) {
+			// should not happen as checked by pace typing
+			throw new IllegalStateException("invalid URL: " + value);
+		}
+	}
+
+	protected String toString(final Object object) {
+		return toFirstString(object);
+	}
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/YearMatch.java

@@ -0,0 +1,52 @@
+
+package eu.dnetlib.pace.tree;
+
+import java.util.Map;
+
+import org.apache.commons.lang3.StringUtils;
+
+import eu.dnetlib.pace.config.Config;
+import eu.dnetlib.pace.tree.support.AbstractStringComparator;
+import eu.dnetlib.pace.tree.support.ComparatorClass;
+
+/**
+ * Returns true if the year of the date field in the given documents are the same, false when any of the two is invalid or it's missing.
+ *
+ * @author claudio
+ */
+@ComparatorClass("yearMatch")
+public class YearMatch extends AbstractStringComparator {
+
+	private int limit = 4;
+
+	public YearMatch(final Map<String, String> params) {
+		super(params);
+	}
+
+	@Override
+	public double compare(final String a, final String b, final Config conf) {
+		final String valueA = getNumbers(getFirstValue(a));
+		final String valueB = getNumbers(getFirstValue(b));
+
+		if (valueA.isEmpty() || valueB.isEmpty())
+			return -1;
+
+		final boolean lengthMatch = checkLength(valueA) && checkLength(valueB);
+		final boolean onemissing = valueA.isEmpty() || valueB.isEmpty();
+
+		return lengthMatch && valueA.equals(valueB) || onemissing ? 1 : 0;
+	}
+
+	protected boolean checkLength(final String s) {
+		return s.length() == limit;
+	}
+
+	protected String getFirstValue(final String value) {
+		return (value != null) && !value.isEmpty() ? StringUtils.left(value, limit) : "";
+	}
+
+	@Override
+	public String toString() {
+		return getClass().getSimpleName() + ":" + super.toString();
+	}
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/support/AbstractComparator.java

@@ -0,0 +1,130 @@
+
+package eu.dnetlib.pace.tree.support;
+
+import java.util.List;
+import java.util.Map;
+
+import com.google.common.base.Joiner;
+import com.google.common.collect.Lists;
+import com.wcohen.ss.AbstractStringDistance;
+
+import eu.dnetlib.pace.common.AbstractPaceFunctions;
+import eu.dnetlib.pace.config.Config;
+
+public abstract class AbstractComparator<T> extends AbstractPaceFunctions implements Comparator<T> {
+
+	/** The ssalgo. */
+	protected AbstractStringDistance ssalgo;
+
+	/** The weight. */
+	protected double weight = 0.0;
+
+	private Map<String, String> params;
+
+	protected AbstractComparator(Map<String, String> params) {
+		this.params = params;
+	}
+
+	protected AbstractComparator(Map<String, String> params, final AbstractStringDistance ssalgo) {
+		this.params = params;
+		this.weight = 1.0;
+		this.ssalgo = ssalgo;
+	}
+
+	/**
+	 * Instantiates a new second string compare algo.
+	 *
+	 * @param weight
+	 *            the weight
+	 * @param ssalgo
+	 *            the ssalgo
+	 */
+	protected AbstractComparator(final double weight, final AbstractStringDistance ssalgo) {
+		this.ssalgo = ssalgo;
+		this.weight = weight;
+	}
+
+	protected AbstractComparator(final AbstractStringDistance ssalgo) {
+		this.ssalgo = ssalgo;
+	}
+
+	/**
+	 * Normalize.
+	 *
+	 * @param d
+	 *            the d
+	 * @return the double
+	 */
+	protected double normalize(double d) {
+		return d;
+	}
+
+	/**
+	 * Distance.
+	 *
+	 * @param a
+	 *            the a
+	 * @param b
+	 *            the b
+	 * @return the double
+	 */
+
+	protected double distance(final String a, final String b, final Config conf) {
+		if (a.isEmpty() || b.isEmpty()) {
+			return -1; // return -1 if a field is missing
+		}
+		double score = ssalgo.score(a, b);
+		return normalize(score);
+	}
+
+	protected double compare(final String a, final String b, final Config conf) {
+		if (a.isEmpty() || b.isEmpty())
+			return -1;
+		return distance(a, b, conf);
+	}
+
+	/**
+	 * Convert the given argument to a List of Strings
+	 *
+	 * @param object
+	 *            function argument
+	 * @return the list
+	 */
+	protected List<String> toList(final Object object) {
+		if (object instanceof List) {
+			return (List<String>) object;
+		}
+
+		return Lists.newArrayList(object.toString());
+	}
+
+	/**
+	 * Convert the given argument to a String
+	 *
+	 * @param object
+	 *            function argument
+	 * @return the list
+	 */
+	protected String toString(final Object object) {
+		if (object instanceof List) {
+			List<String> l = (List<String>) object;
+			return Joiner.on(" ").join(l);
+		}
+
+		return object.toString();
+	}
+
+	protected String toFirstString(final Object object) {
+		if (object instanceof List) {
+			List<String> l = (List<String>) object;
+			return l.isEmpty() ? "" : l.get(0);
+		}
+
+		return object.toString();
+	}
+
+	public double getWeight() {
+		return this.weight;
+	}
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/support/AbstractListComparator.java

@@ -0,0 +1,39 @@
+
+package eu.dnetlib.pace.tree.support;
+
+import java.util.List;
+import java.util.Map;
+
+import com.wcohen.ss.AbstractStringDistance;
+
+import eu.dnetlib.pace.config.Config;
+
+abstract public class AbstractListComparator extends AbstractComparator<List<String>> {
+	protected AbstractListComparator(Map<String, String> params) {
+		super(params);
+	}
+
+	protected AbstractListComparator(Map<String, String> params, AbstractStringDistance ssalgo) {
+		super(params, ssalgo);
+	}
+
+	protected AbstractListComparator(double weight, AbstractStringDistance ssalgo) {
+		super(weight, ssalgo);
+	}
+
+	protected AbstractListComparator(AbstractStringDistance ssalgo) {
+		super(ssalgo);
+	}
+
+	@Override
+	public double compare(Object a, Object b, Config conf) {
+		return compare(toList(a), toList(b), conf);
+	}
+
+	public double compare(final List<String> a, final List<String> b, final Config conf) {
+		if (a.isEmpty() || b.isEmpty())
+			return -1;
+
+		return distance(concat(a), concat(b), conf);
+	}
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/support/AbstractSortedComparator.java

@@ -0,0 +1,40 @@
+
+package eu.dnetlib.pace.tree.support;
+
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+
+import com.google.common.collect.Lists;
+import com.wcohen.ss.AbstractStringDistance;
+
+public abstract class AbstractSortedComparator extends AbstractListComparator {
+
+	/**
+	 * Instantiates a new sorted second string compare algo.
+	 *
+	 * @param weight
+	 *            the weight
+	 * @param ssalgo
+	 *            the ssalgo
+	 */
+	protected AbstractSortedComparator(final double weight, final AbstractStringDistance ssalgo) {
+		super(weight, ssalgo);
+	}
+
+	protected AbstractSortedComparator(final Map<String, String> params, final AbstractStringDistance ssalgo) {
+		super(Double.parseDouble(params.get("weight")), ssalgo);
+	}
+
+	@Override
+	protected List<String> toList(final Object object) {
+		if (object instanceof List) {
+			List<String> fl = (List<String>) object;
+			List<String> values = Lists.newArrayList(fl);
+			Collections.sort(values);
+			return values;
+		}
+
+		return Lists.newArrayList(object.toString());
+	}
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/support/AbstractStringComparator.java

@@ -0,0 +1,46 @@
+
+package eu.dnetlib.pace.tree.support;
+
+import java.util.Map;
+
+import com.wcohen.ss.AbstractStringDistance;
+
+import eu.dnetlib.pace.config.Config;
+
+public abstract class AbstractStringComparator extends AbstractComparator<String> {
+	protected AbstractStringComparator(Map<String, String> params) {
+		super(params);
+	}
+
+	protected AbstractStringComparator(Map<String, String> params, AbstractStringDistance ssalgo) {
+		super(params, ssalgo);
+	}
+
+	protected AbstractStringComparator(double weight, AbstractStringDistance ssalgo) {
+		super(weight, ssalgo);
+	}
+
+	protected AbstractStringComparator(AbstractStringDistance ssalgo) {
+		super(ssalgo);
+	}
+
+	public double distance(final String a, final String b, final Config conf) {
+		if (a.isEmpty() || b.isEmpty()) {
+			return -1; // return -1 if a field is missing
+		}
+		double score = ssalgo.score(a, b);
+		return normalize(score);
+	}
+
+	@Override
+	public double compare(Object a, Object b, Config conf) {
+		return compare(toString(a), toString(b), conf);
+	}
+
+	public double compare(final String a, final String b, final Config conf) {
+		if (a.isEmpty() || b.isEmpty())
+			return -1;
+		return distance(a, b, conf);
+	}
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/support/AggType.java

@@ -0,0 +1,21 @@
+
+package eu.dnetlib.pace.tree.support;
+
+import eu.dnetlib.pace.util.PaceException;
+
+public enum AggType {
+
+	W_MEAN, // weighted mean
+	AVG, // average
+	SUM, MAX, MIN, AND, // used for necessary conditions
+	OR; // used for sufficient conditions
+
+	public static AggType getEnum(String value) {
+
+		try {
+			return AggType.valueOf(value);
+		} catch (IllegalArgumentException e) {
+			throw new PaceException("Undefined aggregation type", e);
+		}
+	}
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/support/Comparator.java

@@ -0,0 +1,12 @@
+
+package eu.dnetlib.pace.tree.support;
+
+import eu.dnetlib.pace.config.Config;
+
+public interface Comparator<T> {
+
+	/*
+	 * return : -1 -> can't decide (i.e. missing field) >0 -> similarity degree (depends on the algorithm)
+	 */
+	public double compare(Object a, Object b, Config conf);
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/support/ComparatorClass.java

@@ -0,0 +1,14 @@
+
+package eu.dnetlib.pace.tree.support;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.TYPE)
+public @interface ComparatorClass {
+
+	public String value();
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/support/FieldConf.java

@@ -0,0 +1,84 @@
+
+package eu.dnetlib.pace.tree.support;
+
+import java.io.IOException;
+import java.io.Serializable;
+import java.util.Map;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+import eu.dnetlib.pace.util.PaceException;
+
+/**
+ * The class that defines the configuration of each field in the decision tree.
+ * */
+public class FieldConf implements Serializable {
+
+	private String field; // name of the field on which apply the comparator
+	private String comparator; // comparator name
+	private double weight = 1.0; // weight for the field (to be used in the aggregation)
+	private Map<String, String> params; // parameters
+
+	private boolean countIfUndefined;
+
+	public boolean isCountIfUndefined() {
+		return countIfUndefined;
+	}
+
+	public void setCountIfUndefined(boolean countIfUndefined) {
+		this.countIfUndefined = countIfUndefined;
+	}
+
+	public FieldConf() {
+	}
+
+	public FieldConf(String field, String comparator, double weight, Map<String, String> params,
+		boolean countIfUndefined) {
+		this.field = field;
+		this.comparator = comparator;
+		this.weight = weight;
+		this.params = params;
+		this.countIfUndefined = countIfUndefined;
+	}
+
+	public String getField() {
+		return field;
+	}
+
+	public void setField(String field) {
+		this.field = field;
+	}
+
+	public String getComparator() {
+		return comparator;
+	}
+
+	public void setComparator(String comparator) {
+		this.comparator = comparator;
+	}
+
+	public double getWeight() {
+		return weight;
+	}
+
+	public void setWeight(double weight) {
+		this.weight = weight;
+	}
+
+	public Map<String, String> getParams() {
+		return params;
+	}
+
+	public void setParams(Map<String, String> params) {
+		this.params = params;
+	}
+
+	@Override
+	public String toString() {
+		try {
+			return new ObjectMapper().writeValueAsString(this);
+		} catch (IOException e) {
+			throw new PaceException("Impossible to convert to JSON: ", e);
+		}
+	}
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/support/FieldStats.java

@@ -0,0 +1,89 @@
+
+package eu.dnetlib.pace.tree.support;
+
+import java.io.IOException;
+import java.io.Serializable;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+import eu.dnetlib.pace.util.PaceException;
+
+/**
+ * The class that contains the result of each comparison in the decision tree
+ * */
+public class FieldStats implements Serializable {
+
+	private double weight; // weight for the field (to be used in the aggregation)
+	private double threshold; // threshold for the field (to be used in some kind of aggregations)
+	private double result; // the result of the comparison
+	private Object a;
+	private Object b;
+
+	private boolean countIfUndefined;
+
+	public FieldStats(double weight, double threshold, double result, boolean countIfUndefined, Object a, Object b) {
+		this.weight = weight;
+		this.threshold = threshold;
+		this.result = result;
+		this.countIfUndefined = countIfUndefined;
+		this.a = a;
+		this.b = b;
+	}
+
+	public double getThreshold() {
+		return threshold;
+	}
+
+	public void setThreshold(double threshold) {
+		this.threshold = threshold;
+	}
+
+	public double getWeight() {
+		return weight;
+	}
+
+	public void setWeight(double weight) {
+		this.weight = weight;
+	}
+
+	public double getResult() {
+		return result;
+	}
+
+	public void setResult(double result) {
+		this.result = result;
+	}
+
+	public boolean isCountIfUndefined() {
+		return countIfUndefined;
+	}
+
+	public void setCountIfUndefined(boolean countIfUndefined) {
+		this.countIfUndefined = countIfUndefined;
+	}
+
+	public Object getA() {
+		return a;
+	}
+
+	public void setA(Object a) {
+		this.a = a;
+	}
+
+	public Object getB() {
+		return b;
+	}
+
+	public void setB(Object b) {
+		this.b = b;
+	}
+
+	@Override
+	public String toString() {
+		try {
+			return new ObjectMapper().writeValueAsString(this);
+		} catch (IOException e) {
+			throw new PaceException("Impossible to convert to JSON: ", e);
+		}
+	}
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/support/MatchType.java

@@ -0,0 +1,25 @@
+
+package eu.dnetlib.pace.tree.support;
+
+public enum MatchType {
+
+	MATCH, NO_MATCH, UNDEFINED;
+
+	public static MatchType parse(String value) {
+
+		if (MATCH.name().equals(value)) {
+			return MATCH;
+		} else if (NO_MATCH.name().equals(value)) {
+			return NO_MATCH;
+		} else {
+			return UNDEFINED;
+		}
+
+//        try {
+//            return MatchType.valueOf(value);
+//        }
+//        catch (IllegalArgumentException e) {
+//            return MatchType.UNDEFINED; //return UNDEFINED if the enum is not parsable
+//        }
+	}
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/support/TreeNodeDef.java

@@ -0,0 +1,170 @@
+
+package eu.dnetlib.pace.tree.support;
+
+import java.io.IOException;
+import java.io.Serializable;
+import java.util.List;
+
+import org.apache.spark.sql.Row;
+import org.apache.spark.sql.types.ArrayType;
+import org.apache.spark.sql.types.DataType;
+import org.apache.spark.sql.types.StringType;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+import eu.dnetlib.pace.config.Config;
+import eu.dnetlib.pace.config.PaceConfig;
+import eu.dnetlib.pace.util.PaceException;
+
+public class TreeNodeDef implements Serializable {
+
+	final static String CROSS_COMPARE = "crossCompare";
+
+	private List<FieldConf> fields;
+	private AggType aggregation;
+
+	private double threshold;
+
+	private String positive;
+	private String negative;
+	private String undefined;
+
+	boolean ignoreUndefined;
+
+	public TreeNodeDef(List<FieldConf> fields, AggType aggregation, double threshold, String positive, String negative,
+		String undefined, boolean ignoreUndefined) {
+		this.fields = fields;
+		this.aggregation = aggregation;
+		this.threshold = threshold;
+		this.positive = positive;
+		this.negative = negative;
+		this.undefined = undefined;
+		this.ignoreUndefined = ignoreUndefined;
+	}
+
+	public TreeNodeDef() {
+	}
+
+	// function for the evaluation of the node
+	public TreeNodeStats evaluate(Row doc1, Row doc2, Config conf) {
+
+		TreeNodeStats stats = new TreeNodeStats();
+
+		// for each field in the node, it computes the
+		for (FieldConf fieldConf : fields) {
+			double weight = fieldConf.getWeight();
+			double result;
+
+			Object value1 = getJavaValue(doc1, fieldConf.getField());
+			Object value2 = getJavaValue(doc2, fieldConf.getField());
+
+			// if the param specifies a cross comparison (i.e. compare elements from different fields), compute the
+			// result for both sides and return the maximum
+			String crossField = fieldConf.getParams().get(CROSS_COMPARE);
+			if (crossField != null) {
+				double result1 = comparator(fieldConf).compare(value1, getJavaValue(doc2, crossField), conf);
+				double result2 = comparator(fieldConf).compare(getJavaValue(doc1, crossField), value2, conf);
+				result = Math.max(result1, result2);
+			} else {
+				result = comparator(fieldConf).compare(value1, value2, conf);
+			}
+
+			stats
+				.addFieldStats(
+					fieldConf.getComparator() + " on " + fieldConf.getField() + " " + fields.indexOf(fieldConf),
+					new FieldStats(
+						weight,
+						Double.parseDouble(fieldConf.getParams().getOrDefault("threshold", "1.0")),
+						result,
+						fieldConf.isCountIfUndefined(),
+						value1,
+						value2));
+		}
+
+		return stats;
+	}
+
+	public Object getJavaValue(Row row, String name) {
+		int pos = row.fieldIndex(name);
+		if (pos >= 0) {
+			DataType dt = row.schema().fields()[pos].dataType();
+			if (dt instanceof StringType) {
+				return row.getString(pos);
+			} else if (dt instanceof ArrayType) {
+				return row.getList(pos);
+			}
+		}
+
+		return null;
+	}
+
+	private Comparator comparator(final FieldConf field) {
+
+		return PaceConfig.resolver.getComparator(field.getComparator(), field.getParams());
+	}
+
+	public List<FieldConf> getFields() {
+		return fields;
+	}
+
+	public void setFields(List<FieldConf> fields) {
+		this.fields = fields;
+	}
+
+	public AggType getAggregation() {
+		return aggregation;
+	}
+
+	public void setAggregation(AggType aggregation) {
+		this.aggregation = aggregation;
+	}
+
+	public double getThreshold() {
+		return threshold;
+	}
+
+	public void setThreshold(double threshold) {
+		this.threshold = threshold;
+	}
+
+	public String getPositive() {
+		return positive;
+	}
+
+	public void setPositive(String positive) {
+		this.positive = positive;
+	}
+
+	public String getNegative() {
+		return negative;
+	}
+
+	public void setNegative(String negative) {
+		this.negative = negative;
+	}
+
+	public String getUndefined() {
+		return undefined;
+	}
+
+	public void setUndefined(String undefined) {
+		this.undefined = undefined;
+	}
+
+	public boolean isIgnoreUndefined() {
+		return ignoreUndefined;
+	}
+
+	public void setIgnoreUndefined(boolean ignoreUndefined) {
+		this.ignoreUndefined = ignoreUndefined;
+	}
+
+	@Override
+	public String toString() {
+		try {
+			return new ObjectMapper().writeValueAsString(this);
+		} catch (IOException e) {
+			throw new PaceException("Impossible to convert to JSON: ", e);
+		}
+	}
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/support/TreeNodeStats.java

@@ -0,0 +1,134 @@
+
+package eu.dnetlib.pace.tree.support;
+
+import java.io.Serializable;
+import java.util.HashMap;
+import java.util.Map;
+
+public class TreeNodeStats implements Serializable {
+
+	private Map<String, FieldStats> results; // this is an accumulator for the results of the node
+
+	public TreeNodeStats() {
+		this.results = new HashMap<>();
+	}
+
+	public Map<String, FieldStats> getResults() {
+		return results;
+	}
+
+	public void addFieldStats(String id, FieldStats fieldStats) {
+		this.results.put(id, fieldStats);
+	}
+
+	public int fieldsCount() {
+		return this.results.size();
+	}
+
+	public int undefinedCount() {
+		int undefinedCount = 0;
+		for (FieldStats fs : this.results.values()) {
+			if (fs.getResult() == -1)
+				undefinedCount++;
+		}
+		return undefinedCount;
+	}
+
+	public double scoreSum() {
+		double scoreSum = 0.0;
+		for (FieldStats fs : this.results.values()) {
+			if (fs.getResult() >= 0.0) {
+				scoreSum += fs.getResult();
+			}
+		}
+		return scoreSum;
+	}
+
+	// return the sum of the weights without considering the fields with countIfMissing=false && result=-1
+	public double weightSum() {
+		double weightSum = 0.0;
+		for (FieldStats fs : this.results.values()) {
+			if (fs.getResult() >= 0.0 || (fs.getResult() < 0.0 && fs.isCountIfUndefined())) {
+				weightSum += fs.getWeight();
+			}
+		}
+		return weightSum;
+	}
+
+	public double weightedScoreSum() {
+		double weightedScoreSum = 0.0;
+		for (FieldStats fs : this.results.values()) {
+			if (fs.getResult() >= 0.0) {
+				weightedScoreSum += fs.getResult() * fs.getWeight();
+			}
+		}
+		return weightedScoreSum;
+	}
+
+	public double max() {
+		double max = -1.0;
+		for (FieldStats fs : this.results.values()) {
+			if (fs.getResult() > max)
+				max = fs.getResult();
+		}
+		return max;
+	}
+
+	public double min() {
+		double min = 100.0; // random high value
+		for (FieldStats fs : this.results.values()) {
+			if (fs.getResult() < min) {
+				if (fs.getResult() >= 0.0 || (fs.getResult() == -1 && fs.isCountIfUndefined()))
+					min = fs.getResult();
+			}
+		}
+		return min;
+	}
+
+	// if at least one is true, return 1.0
+	public double or() {
+		for (FieldStats fieldStats : this.results.values()) {
+			if (fieldStats.getResult() >= fieldStats.getThreshold())
+				return 1.0;
+		}
+		return 0.0;
+	}
+
+	// if at least one is false, return 0.0
+	public double and() {
+		for (FieldStats fieldStats : this.results.values()) {
+
+			if (fieldStats.getResult() == -1) {
+				if (fieldStats.isCountIfUndefined())
+					return 0.0;
+			} else {
+				if (fieldStats.getResult() < fieldStats.getThreshold())
+					return 0.0;
+			}
+
+		}
+		return 1.0;
+	}
+
+	public double getFinalScore(AggType aggregation) {
+
+		switch (aggregation) {
+			case AVG:
+				return scoreSum() / fieldsCount();
+			case SUM:
+				return scoreSum();
+			case MAX:
+				return max();
+			case MIN:
+				return min();
+			case W_MEAN:
+				return weightedScoreSum() / weightSum();
+			case OR:
+				return or();
+			case AND:
+				return and();
+			default:
+				return 0.0;
+		}
+	}
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/support/TreeProcessor.java

@@ -0,0 +1,92 @@
+
+package eu.dnetlib.pace.tree.support;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.spark.sql.Row;
+
+import eu.dnetlib.pace.config.Config;
+import eu.dnetlib.pace.util.PaceException;
+
+/**
+ * The compare between two documents is given by the weighted mean of the field distances
+ */
+public class TreeProcessor {
+
+	private static final Log log = LogFactory.getLog(TreeProcessor.class);
+
+	private Config config;
+
+	public TreeProcessor(final Config config) {
+		this.config = config;
+	}
+
+	// row based copies
+
+	public boolean compare(final Row a, final Row b) {
+		// evaluate the decision tree
+		return evaluateTree(a, b).getResult() == MatchType.MATCH;
+	}
+
+	public TreeStats evaluateTree(final Row doc1, final Row doc2) {
+
+		TreeStats treeStats = new TreeStats();
+
+		String nextNodeName = "start";
+
+		do {
+
+			TreeNodeDef currentNode = config.decisionTree().get(nextNodeName);
+			// throw an exception if the node doesn't exist
+			if (currentNode == null)
+				throw new PaceException("Missing tree node: " + nextNodeName);
+
+			TreeNodeStats stats = currentNode.evaluate(doc1, doc2, config);
+			treeStats.addNodeStats(nextNodeName, stats);
+
+			// if ignoreUndefined=false the miss is considered as undefined
+			if (!currentNode.isIgnoreUndefined() && stats.undefinedCount() > 0) {
+				nextNodeName = currentNode.getUndefined();
+			}
+			// if ignoreUndefined=true the miss is ignored and the score computed anyway
+			else if (stats.getFinalScore(currentNode.getAggregation()) >= currentNode.getThreshold()) {
+				nextNodeName = currentNode.getPositive();
+			} else {
+				nextNodeName = currentNode.getNegative();
+			}
+
+		} while (MatchType.parse(nextNodeName) == MatchType.UNDEFINED);
+
+		treeStats.setResult(MatchType.parse(nextNodeName));
+		return treeStats;
+	}
+
+	public double computeScore(final Row doc1, final Row doc2) {
+		String nextNodeName = "start";
+		double score = 0.0;
+
+		do {
+
+			TreeNodeDef currentNode = config.decisionTree().get(nextNodeName);
+			// throw an exception if the node doesn't exist
+			if (currentNode == null)
+				throw new PaceException("The Tree Node doesn't exist: " + nextNodeName);
+
+			TreeNodeStats stats = currentNode.evaluate(doc1, doc2, config);
+
+			score = stats.getFinalScore(currentNode.getAggregation());
+			// if ignoreUndefined=false the miss is considered as undefined
+			if (!currentNode.isIgnoreUndefined() && stats.undefinedCount() > 0) {
+				nextNodeName = currentNode.getUndefined();
+			}
+			// if ignoreUndefined=true the miss is ignored and the score computed anyway
+			else if (stats.getFinalScore(currentNode.getAggregation()) >= currentNode.getThreshold()) {
+				nextNodeName = currentNode.getPositive();
+			} else {
+				nextNodeName = currentNode.getNegative();
+			}
+		} while (MatchType.parse(nextNodeName) == MatchType.UNDEFINED);
+
+		return score;
+	}
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/tree/support/TreeStats.java

@@ -0,0 +1,52 @@
+
+package eu.dnetlib.pace.tree.support;
+
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.Map;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+import eu.dnetlib.pace.util.PaceException;
+
+public class TreeStats {
+
+	// <layer_id, <field:comparator, result>>
+	Map<String, TreeNodeStats> stats;
+	MatchType result;
+
+	public TreeStats() {
+		this.stats = new HashMap<>();
+		this.result = MatchType.NO_MATCH;
+	}
+
+	public MatchType getResult() {
+		return this.result;
+	}
+
+	public void setResult(MatchType result) {
+		this.result = result;
+	}
+
+	public Map<String, TreeNodeStats> getStats() {
+		return stats;
+	}
+
+	public void setStats(Map<String, TreeNodeStats> stats) {
+		this.stats = stats;
+	}
+
+	public void addNodeStats(String layerID, TreeNodeStats treeNodeStats) {
+		this.stats.put(layerID, treeNodeStats);
+	}
+
+	@Override
+	public String toString() {
+		try {
+			return new ObjectMapper().writerWithDefaultPrettyPrinter().writeValueAsString(this);
+		} catch (IOException e) {
+			throw new PaceException("Impossible to convert to JSON: ", e);
+		}
+	}
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/util/BlockProcessor.java

@@ -0,0 +1,146 @@
+
+package eu.dnetlib.pace.util;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.apache.commons.lang3.StringUtils;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.spark.sql.Row;
+import org.apache.spark.sql.types.ArrayType;
+import org.apache.spark.sql.types.DataType;
+import org.apache.spark.sql.types.StringType;
+
+import eu.dnetlib.pace.config.DedupConfig;
+import eu.dnetlib.pace.config.WfConfig;
+import eu.dnetlib.pace.tree.support.TreeProcessor;
+
+public class BlockProcessor {
+
+	public static final List<String> accumulators = new ArrayList<>();
+
+	private static final Log log = LogFactory.getLog(BlockProcessor.class);
+
+	private DedupConfig dedupConf;
+
+	private final int identifierFieldPos;
+	private final int orderFieldPos;
+
+	public static void constructAccumulator(final DedupConfig dedupConf) {
+		accumulators.add(String.format("%s::%s", dedupConf.getWf().getEntityType(), "records per hash key = 1"));
+		accumulators
+			.add(
+				String
+					.format(
+						"%s::%s", dedupConf.getWf().getEntityType(), "missing " + dedupConf.getWf().getOrderField()));
+		accumulators
+			.add(
+				String
+					.format(
+						"%s::%s", dedupConf.getWf().getEntityType(),
+						String
+							.format(
+								"Skipped records for count(%s) >= %s", dedupConf.getWf().getOrderField(),
+								dedupConf.getWf().getGroupMaxSize())));
+		accumulators.add(String.format("%s::%s", dedupConf.getWf().getEntityType(), "skip list"));
+		accumulators.add(String.format("%s::%s", dedupConf.getWf().getEntityType(), "dedupSimilarity (x2)"));
+		accumulators
+			.add(String.format("%s::%s", dedupConf.getWf().getEntityType(), "d < " + dedupConf.getWf().getThreshold()));
+	}
+
+	public BlockProcessor(DedupConfig dedupConf, int identifierFieldPos, int orderFieldPos) {
+		this.dedupConf = dedupConf;
+		this.identifierFieldPos = identifierFieldPos;
+		this.orderFieldPos = orderFieldPos;
+	}
+
+	public void processSortedRows(final List<Row> documents, final Reporter context) {
+		if (documents.size() > 1) {
+//            log.info("reducing key: '" + key + "' records: " + q.size());
+			processRows(documents, context);
+
+		} else {
+			context.incrementCounter(dedupConf.getWf().getEntityType(), "records per hash key = 1", 1);
+		}
+	}
+
+	private void processRows(final List<Row> queue, final Reporter context) {
+
+		for (int pivotPos = 0; pivotPos < queue.size(); pivotPos++) {
+			final Row pivot = queue.get(pivotPos);
+
+			final String idPivot = pivot.getString(identifierFieldPos); // identifier
+			final Object fieldsPivot = getJavaValue(pivot, orderFieldPos);
+			final String fieldPivot = (fieldsPivot == null) ? "" : fieldsPivot.toString();
+			final WfConfig wf = dedupConf.getWf();
+
+			if (fieldPivot != null) {
+				int i = 0;
+				for (int windowPos = pivotPos + 1; windowPos < queue.size(); windowPos++) {
+					final Row curr = queue.get(windowPos);
+					final String idCurr = curr.getString(identifierFieldPos); // identifier
+
+					if (mustSkip(idCurr)) {
+						context.incrementCounter(wf.getEntityType(), "skip list", 1);
+						break;
+					}
+
+					if (++i > wf.getSlidingWindowSize()) {
+						break;
+					}
+
+					final Object fieldsCurr = getJavaValue(curr, orderFieldPos);
+					final String fieldCurr = (fieldsCurr == null) ? null : fieldsCurr.toString();
+
+					if (!idCurr.equals(idPivot) && (fieldCurr != null)) {
+
+						final TreeProcessor treeProcessor = new TreeProcessor(dedupConf);
+
+						emitOutput(treeProcessor.compare(pivot, curr), idPivot, idCurr, context);
+					}
+				}
+			}
+		}
+	}
+
+	public Object getJavaValue(Row row, int pos) {
+		DataType dt = row.schema().fields()[pos].dataType();
+		if (dt instanceof StringType) {
+			return row.getString(pos);
+		} else if (dt instanceof ArrayType) {
+			return row.getList(pos);
+		}
+
+		return null;
+	}
+
+	private void emitOutput(final boolean result, final String idPivot, final String idCurr, final Reporter context) {
+
+		if (result) {
+			if (idPivot.compareTo(idCurr) <= 0) {
+				writeSimilarity(context, idPivot, idCurr);
+			} else {
+				writeSimilarity(context, idCurr, idPivot);
+			}
+			context.incrementCounter(dedupConf.getWf().getEntityType(), "dedupSimilarity (x2)", 1);
+		} else {
+			context.incrementCounter(dedupConf.getWf().getEntityType(), "d < " + dedupConf.getWf().getThreshold(), 1);
+		}
+	}
+
+	private boolean mustSkip(final String idPivot) {
+		return dedupConf.getWf().getSkipList().contains(getNsPrefix(idPivot));
+	}
+
+	private String getNsPrefix(final String id) {
+		return StringUtils.substringBetween(id, "|", "::");
+	}
+
+	private void writeSimilarity(final Reporter context, final String from, final String to) {
+		final String type = dedupConf.getWf().getEntityType();
+
+		context.emit(type, from, to);
+	}
+
+}

dhp-pace-core/src/main/java/eu/dnetlib/pace/util/Capitalise.java

@@ -0,0 +1,18 @@
+
+package eu.dnetlib.pace.util;
+
+import org.apache.commons.lang3.text.WordUtils;
+
+import com.google.common.base.Function;
+
+public class Capitalise implements Function<String, String> {
+
+	private final char[] DELIM = {
+		' ', '-'
+	};
+
+	@Override
+	public String apply(final String s) {
+		return WordUtils.capitalize(s.toLowerCase(), DELIM);
+	}
+};