Florian Hacques
email: florian.hacques@etu.univ-nantes.fr

Hala Skaf-Molli

Pascal Molli

Sara El

Pascal Skaf

Molli

PFed: Recommending Plausible Federated SPARQL Queries

Keywords: Semantic Web, Federated SPARQL Query, Plausible, Joinable

Federated SPARQL queries allow to query multiple interlinked datasets hosted by remote SPARQL endpoints. However, finding federated queries over a growing number of datasets is challenging. In this paper, we propose PFed, an approach to recommend plausible federated queries based on real query logs of different datasets. The problem is not to find similar federated queries, but plausible complementary queries over different datasets. Starting with a real SPARQL query from a given log, PFed stretches the query with real queries from different logs. To prune the research space, PFed proposes semantic summary to prune the query logs. Experimental results with real logs of DBpedia and SWDF demonstrate that PFed is able to prune drastically the logs and recommend plausible federated queries.

Introduction

Following the Linked Open Data cloud (LOD) principles many datasets have been published. Federated SPARQL query engines [START_REF] Schwarte | Fedx: Optimization techniques for federated query processing on linked data[END_REF][START_REF] Acosta | ANAPSID: an adaptive query processing engine for SPARQL endpoints[END_REF] have been developed to query multiple interlinked datasets hosted by remote SPARQL endpoints. However, finding federated queries over a growing number of datasets is challenging. This requires to fully understand the datasets and find potential joins among them. In this paper, we propose PFed, an original approach to recommend federated queries for end-users. Instead of using datasets to recommend federated queries, PFed recommends federated queries using query logs of different SPARQL endpoints. This is not a classical recommendation problem. In recommender systems [START_REF] Adomavicius | Toward the next generation of recommender systems: A survey of the state-of-the-art[END_REF], the problem is to recommend resources (or items) for users based on similar ones already seen by the users. In PFed, we start with a SPARQL query from a given log and we stretch this query with real queries from other existing query logs. The main advantage of using real logs rather than using datasets is to produce plausible federated queries, i.e. queries that generated by combining real queries. This is useful, especially for data portal owners who can recommend federated queries for end-users. Imagine a data portal such as Sage 1 , or LodLaundromat 2 hosting thousands of linked datasets. The portal owner can see that some users are looking for information about "United Kingdom" in DBpedia, others are looking for conferences in SWDF dataset. Using PFed, the portal owner can suggest to extended conferences with information about country.

To illustrate, consider queries extracted from real SPARQL query logs of SWDF (SWDF 2012) and DBpedia (DBpedia 3.5.1) 3 presented in Figure 1. ? c o u n t r y dbp : c a p i t a l ? c a p i t a l . ? c a p i t a l geo : l a t ? l a t . ? c a p i t a l geo : l o n g ? l o n g }# r e s u l t s : 4 Consider the Q1S from the log of SWDF, this query can be extended with the query Q1D from the log of DBpedia. The result is the SPARQL 1.1 federated Query Q1S1D given in Figure 2. Q1S1D is generated by joining the variable ?place of the query Q1S, i.e. the object of the predicate foaf:based_near with the variable ?country of the query Q1D, i.e. the subject of the predicates rdfs:label and dbpedia2:capital. The joined variable ?country has been renamed by ?place, in the generated query Q1S1D. The execution of this query over a federation of SWDF and DBpedia produces 1388 results.

The generated query Q1S1D can be recommended as a plausible federated query. In the same way, we can generate a more complex federated query such as the query Q2S2D shown in Figure 2b. Q2S2D is obtained by extending the query Q2S from the log of SWDF with the query Q2D from the log of DBpedia. The joining variable ?sameAs is renamed as ?person in Q2S2D.

Recommending plausible federated queries is challenging because the size of logs. The log of DBpedia contains 217 812 queries, and the log of SWDF contains 64 030 queries [START_REF] Saleem | Feasible: A feature-based sparql benchmark generation framework[END_REF]. To overcome this problem, we propose a semantic summary that allows to reduce drastically the size of logs by excluding non joinable queries. The main contributions of the paper are:

a new semantic summary for pruning query logs.

an algorithm to exclude non joinable queries from logs. Fig. 2: Plausible federated query generated from logs of SWDF and DBpedia in Figure 1 an algorithm for generating plausible federated queries using the pruned logs.

an experimentation using real queries logs of SWDF 2012 and DBpedia 3.5.1.

This paper is organized as follows. Section 2 summarizes related works. Section 3 details PFed approach and algorithms. Section 4 presents our experimental results. Finally, conclusions and future work are outlined in Section 5.

Related Work

Many efforts have been done to automatically generate SPARQL queries, either for individual dataset [START_REF] Aluç | Diversified stress testing of RDF data management systems[END_REF][START_REF] Saleem | Feasible: A feature-based sparql benchmark generation framework[END_REF] or multiple datasets as Splodge [START_REF] Görlitz | SPLODGE: systematic generation of SPARQL benchmark queries for linked open data[END_REF] and Fed-Bench [START_REF] Schmidt | Fedbench: A benchmark suite for federated semantic data query processing[END_REF]. Federated queries benchmarks have been proposed for evaluating the performance of federated query engine. Existing benchmark rely either on hand-crafted queries or on automatically generated ones.

FedBench [START_REF] Schmidt | Fedbench: A benchmark suite for federated semantic data query processing[END_REF] rely on hand-crafted queries. The datasets of FedBench are real datasets preselected from the Linked Data Cloud, e.g. Life Science, Cross domain. FedBench is commonly used for the evaluation of federated query engines. FedBench is not designed to recommend plausible federated queries over a federation of SPARQL endpoints. LargeRDFBench [START_REF] Saleem | LargeRDFBench: A billion triples benchmark for sparql endpoint federation[END_REF] attempts to generate more realistic federated queries. The benchmark comprises a total of 32 queries for SPARQL endpoint federation. Queries are ranging from simple queries extracted from FedBench queries and large data queries created by the authors with the help of the expert domain. As FedBench, LargeRDFBench are designed for preselected datasets and queries are designed for specific domains and cannot be used for automatic generation of realistic federated queries.

Splodge [START_REF] Görlitz | SPLODGE: systematic generation of SPARQL benchmark queries for linked open data[END_REF] proposes heuristics for automatic query generation. Splodge generates only conjunctive queries of triple patterns, i.e., Basic Graph Patterns (BGP) with bound predicate, unbound subject and unbound object. Other SPARQL operators such as FILTER, OPTIONAL are not considered. However, recent analytical study of large SPARQL query logs [START_REF] Bonifati | An analytical study of large SPARQL query logs[END_REF] shows that 74.83% of studied queries have JOIN, FILTER and OPTIONAL and only 7.49% have JOIN alone (conjunctive queries). Consequently, the queries of Splodge cannot reflect the reality. Feta [START_REF] Nassopoulos | FETA: Federated QuEry TrAcking for Linked Data[END_REF] is a federated query tracker that computes Basic Graph Patterns from a federated log. It supposes the existence of a federated query log. In this work, we want to build and recommend federated queries rather than analyzing federated query logs.

Existing approaches of automatic generation of federated queries do not reflect reality and hand-crafted federated queries are designed for specific datasets with the purpose to stress the performance of a federated query engine. Benchmarks are not designed for recommending plausible federated queries.

Generation of Plausible Federated Queries

Intuitively, for generating a plausible federated query over n datasets, we propose to start by combing (joining) the query logs log 1 and log 2 of two datasets d 1 and d 2 , respectively. Then, we generate new federated queries by joining the resulting queries and the log log 3 of the dataset d 3 . We repeat the same process iteratively until processing the n query logs.

In the following, for simplicity, we restrict our discussion to the case of two real query logs. Given two queries Q 1 and Q 2 belong to different query logs, we want to build a plausible federated query F Q. We call F Q a plausible federated query because it is composed of two real queries. Our intuition is F Q is more likely to be a real query than a synthetic one.

Datasets capabilities

We can distinguish different type of join combinations: subject-subject or objectsubject leading to different query structures star-shaped, path-shaped, or hybrid queries [START_REF] Schmidt | Fedbench: A benchmark suite for federated semantic data query processing[END_REF]. To find joinable predicates, one can rely on the Vocabulary Of Interlinked Datasets VoID [START_REF] Alexander | Describing linked datasets[END_REF]. This vocabulary describes metadata about RDF datasets and the linkset. A linkset is a collection of RDF links between two datasets 4 . An RDF link is an RDF triple whose subject and object are described in different datasets. This corresponds to the joinable predicates in the example of the Figure 2. However, we cannot use VoID to detect joinable predicates because a large number of RDF datasets do not provide VoID [START_REF] Vandenbussche | Sparqles: Monitoring public sparql endpoints[END_REF], only 13.65% of datasets 5 (77/564) present a VoID description.

Another solution is to use the capabilities of data sources as defined in Hibiscus [START_REF] Saleem | Hibiscus: Hypergraph-based source selection for sparql endpoint federation[END_REF] to check the possible existence of matching. According to [START_REF] Saleem | Hibiscus: Hypergraph-based source selection for sparql endpoint federation[END_REF], the data summary of a source d ∈ D is the set CA(d) of all capabilities of that source. In Hibiscus, this summary is used to remove endpoints during the source selection during federated query processing The total number of capabilities of a source is equal to the number of distinct predicates in it. The definition of the authorities of a subject or an object relies on the analysis of the Unified Resource Identifier (URI) syntax. The URI syntax consists of a hierarchical sequence of components referred to as the scheme, authority, path, query, and fragment 6 . For example, the uri <http://dbpedia. org/ontology/Plant> contains a schema "http", an authority "dbpedia.org" and a path "ontology/Plant". To compute the set of capabilities for a source, the first two components (path, authority) are combined as the authority of the URI. Figure 3 presents a sample of the summary of SWDF 2012 and DBpedia 3.5.1. For instance, in Figure 3a, the first capability of SWDF data source is the predicate foaf:based_near, its subject authority is <http://data.semanticweb. org> and its object authorities are <http://dbpedia.org>, <http://www.w3. org>, <http://sws.geonames.org>, and <http://data.semanticweb.org>.

Authority summary allows to prune the query logs only if many predicates have different subjects or objects authority. However, this not always the case, especially for the subject authority. For instance, the majority of subjects of DBpedia have the authority <http://dbpedia.org>, only six predicates out of 39672 predicates of DBpedia 3.5.1 do not have <http://dbpedia.org> as a subject authority. Therefore, if a query Q 1 in SWDF query log is joinable with a query Q 2 in DBpedia query log on the subject authority <http://dbpedia. org>, then Q 1 will be joinable with a large number of queries in the log of DBpedia. Therefore, for query logs of SWDF and DBpedia, authority summary will prune mostly queries with unbounded predicates.

To further prune the log, we define new data summary that considers semantic of subjects and objects for finding joinable predicates. Intuitively, a subject or an object from one dataset could be joinable with a subject or object from another dataset, if they share some common types. More precisely, we define a new summary called Class summary. A class summary is a set of classes capabilities.

Definition 2 (Class Capability). Given a source d, a class capability is a triple (p, SC(d, p), OC(d, p)), which contains (1) a predicate p in d, (2) the set SC(d, p) of all distinct subject classes of p in d and (3) the set OA(d, p) of all distinct object classes of p in d.

Classes capabilities can be computed using SPARQL queries. But since entities are reused across datasets, types of the subjects and objects for predicates maybe not defined locally. Therefore, we need to perform a SPARQL federated query to compute classes capabilities. We use only the direct classes of subjects and objects to find common classes, we do not use inferences because schemas information are not always available [START_REF] Neumann | Characteristic sets: Accurate cardinality estimation for rdf queries with multiple joins[END_REF], and we restrict the computation to

Definition 4 (Predicate Joinable Path). joinableP ath(p

1 , p 2 ) = true, if OA(d 1 , p 1 ) ∩ SA(d 2 , p 2 ) = ∅ and OC(d 1 , p 1 ) ∩ SC(d 2 , p 2 ) = ∅.

Definition 5 (Predicate Joinable Star). joinableStar(p

1 , p 2 ) = true, if SA(d 1 , p 1 ) ∩ SA(d 2 , p 2 ) = ∅ and SC(d 1 , p 1 ) ∩ SC(d 2 , p 2 ) = ∅.
The hybrid join pattern is built as a mix of a path join pattern and a star join pattern. Figure 5 presents possible structures of hybrid federated queries. The query generated in Figure 5a is built from the path query of

p 1 ∈ Q 1 , Q 1 ∈ log 1 and p 3 ∈ Q 2 , Q 2 ∈ log 2 .
The query generated in Figure 5b built from the star query of

p 1 ∈ Q 1 , Q 1 ∈ log 1 and p 2 ∈ Q 2 , Q 2 ∈ log 2 .

Algorithm 1: Joinable predicates

Input: AS1, CS1, AS2, CS2

Authorities and classes summaries for the two datasets Output: JP red Set of joinable predicates 1 Function JoinPred(AS1, CS1, AS2, CS2): The objective now is to prune query logs and conserve only joinable queries. First, the algorithm 1 uses summaries to conserve predicate joinable (predicate joinable path), then the algorithm 2 excludes non joinable queries from logs. For logs in Figure 3, the algorithm 1 keeps the couple (foaf:based_near,dbpedia2:capital) because they share http://dbpedia.org as object and subject authority, respectively, and they share Country, Place and PopulatedPlace as object and subject classes, respectively.

2 JP red ←-∅; 3 foreach cap1 ∈ AS1 do 4 foreach cap2 ∈ AS2 do 5 if AS1.objAuthority(cap1) ∩ AS2.sbjAuthority(cap2) = ∅ then 6 if CS1.objClasses(cap1) ∩ CS2.sbjClasses(cap2) = ∅ then 7 JP red ←-JP red ∪ (cap1.predicate, cap2.predicate);
To compute predicate joinable star, we only need to modify conditions in lines 5-6 of the algorithm 1 to compare subjects parts of both capabilities. With this modification, the algorithm will keep the couple (skos:prefLabel,dbo:abstract) as they share same authorities and classes as subjects. The algorithm 1 can be iteratively called to compute predicate joinable path or star for more than two datasets.

We use the result of the algorithm 1 to exclude non joinable queries as shown in the algorithm2. After the execution of the algorithm 2 for joinable path, Q1S Algorithm 2: Joinable queries Input: log1, log2, JP red Logs of both dataset and the set of corresponding joinable predicates Output: f eds Set of federated queries 1 Function GenFed(log1, log2, JP red): 11 End Function of SWDF and Q2D of DBpedia will be preserved, because they have the joinable predicates (foaf:based_near,dbpedia2:capital) as shown previously. We exclude Q3S because it cannot be joined with any query from dbpedia, i.e. no predicate in DBpedia has <http://data.semanticweb.org> as subject authority. We also eliminate Q3D because the capability of unbound predicate is undefined.

2 f eds ←-∅; 3 foreach Q1 ∈ log1 do 4 foreach Q2 ∈ log2 do 5 if ∃(p1, p2)|p1 ∈ Q1, p2 ∈ Q2 ∧ (p1, p2) ∈ JP red then 6 f eds ←-f eds ∪ (Q1, Q2)

Building plausible federated queries

We rely on the results of the algorithm 2 to build plausible federated queries. For sake of simplification, we start by illustrating the generating of minimal federated queries PFed min . A minimal federated contains one triple from log 1 and one triple from log 2 .

In order to construct a path (star) join, we substitute the object (subject) of p 1 and the subject of p 2 by the same value as given in the table 1. Figure 6a presents a minimal path-shaped federated query between foaf:based_near ∈ Q1S and dbpedia2:capital ∈ Q1D in Figure 3. Figure 6b presents a minimal star-shaped federated query between skos:prefLabel ∈ Q4S and dbo:thumbnail ∈ Q4D.

PFed min are not required to generate plausible federated queries. But they can help to reduce the number of potential joinable predicates by only keeping PFed min producing results. They can also be used to navigate through datasets. The construction of Q PFed is tricky, if the original queries contain OP-TIONAL operator. We have to construct only correct plausible federated query. A plausible federated query is correct if it is well designed [START_REF] Pérez | Semantics and complexity of sparql[END_REF] and servicesafeness [START_REF] Arenas | Federation and navigation in sparql 1.1[END_REF].

Definition 6 (Well designed[10]).

A graph pattern P is well designed if for every occurrence of a sub-pattern P' = (P1 OPT P2) of P and for every variable ?X occurring in P, the following condition holds: if ?X occurs both inside P2 and outside P', then it also occurs in P1.

The federated query in Figure 7c is not well designed because the variable ?o2 occurs in P2 and outside the P' (i.e. clause SERVICE <dataset2>), but it not occurs in P1.

The service-safeness provides condition that ensures that a SPARQL query containing SERVICE operator can be safely evaluated. Our generated queries ensure service-safeness because each SERVICE clause has only bounded service, i.e., during the construction the URI of the SPARQL endpoints are known.

The main issue is to build well designed queries to avoid cartesian products as illustrated in Figure 7c. If Q 2 does not have a mapping for ?o2, a result will still produced. To avoid this problem, we define the following strategy:

-If Q 1 and Q 2 are conjunctive queries (a.k.a BGPs) then Q PFed = Q 1 Q 2 , Q PFed is a simple concatenation of queries (Q 1 . Q 2 ),

Evaluation

The objective of the evaluation is to answer empirically the following questions: We observe also an important reduction in the number of minimal federated queries PFed min (Table 5). This reduction is important as each PFed min contributes to many federated queries.

With Authorities

With authorities and classes path-shaped star-shaped path-shaped star-shaped 1 146 687 352 432 We generate star-shaped plausible federated queries based on skos:prefLable from SWDF and dbpedia:thumbnail from DBPedia (see table 6). The 42 generated queries are executed correctly and 28 of these queries produce results.

Conclusion and Future Work

We presented PFed an approach for automatic generation of plausible federated queries based on real query logs. PFed starts by pruning the logs to exclude non joinable queries using data summaries. The first one is based on the authorities and the second is based on the type of subjects and objects of predicates. Experimentations with real query logs of SWDF and DBpedia demonstrate that PFed is able to prune considerably the logs and generate plausible federated queries.

As future work, we would like to experiment PFed with more real query logs and produce plausible federated queries over a large number of SPARQL endpoints. Finally, we plan to extend PFed with statistical information to generate only queries that return results.

Q1S:

  SELECT * WHERE { ? i n s t r d f : t y p e ? d C l a s s . ? i n s t f o a f : b a s e d _ n e a r ? p l a c e }# r e s u l t s : 5 0 2 5 Q3S : SELECT * WHERE { {? p a p e r s w r c : a u t h o r ? a u t h o r } UNION {? p a p e r f o a f : maker ? a u t h o r } OPTIONAL {? p a p e r s w r c : a b s t r a c t ? a b s t r a c t } }# r e s u l t s : 2 1 6 4 9 (a) SWDF query log Q1D : SELECT * WHERE { ? c o u n t r y r d f s : l a b e l " U n i t e d Kingdom " @en .

Q3D:Fig. 1 :

 1 Fig. 1: SPARQL queries from the logs of SWDF and DBpedia

SELECTFig. 6 :

 6 Fig.6: Minimal federated queries generated from pruned logs of SWDF and DBpedia in Figure3

Fig. 7 :

 7 Fig. 7: A non well designed federated query

:Country, dbo:Place, dbo:PopulatedPlace,

	[] a ds:Service ;	[] a ds:Service ;
	ds:url <http://swdf-2012> ;	ds:url <http://dbpedia-3.5.1> ;
	ds:capability [	ds:capability [
	ds:predicate foaf:based_near ;	ds:predicate dbpedia2:capital ;
	ds:sbjAuthority <http://data.semanticweb.org> ;	ds:sbjAuthority <http://dbpedia.org> ;
	ds:objAuthority <http://dbpedia.org>,	ds:objAuthority <http://dbpedia.org> ; ] ;
	<http://www.w3.org>, <http://sws.geonames.org>,	ds:capability [
	<http://data.semanticweb.org> ; ] ;	ds:predicate dbo:birthDate ;
	ds:capability [	ds:sbjAuthority <http://dbpedia.org> ; ] ;
	ds:predicate owl:sameAs ;	ds:capability [
	ds:sbjAuthority <http://data.semanticweb.org> ;	ds:predicate rdfs:comment ;
		ds:sbjAuthority <http://dbpedia.org> ; ] ;
		ds:capability [
		ds:predicate foaf:name ;
		ds:sbjAuthority <http://dbpedia.org> ; ] ;
		ds:capability [
		ds:predicate dbo:abstract ;
		ds:sbjAuthority <http://dbpedia.org> ; ] ;
		ds:capability [
		ds:predicate dbo:thumbnail ;
	(a) SWDF data summary
		[] a ds:Service ;
		ds:url <http://dbpedia-3.5.1> ;
		ds:capability [
		ds:predicate: dbpedia2:capital ;
		sbjClasses:
	] ;
	ds:capability [
	ds:predicate: skos:prefLabel ;
	sbjClasses: foaf:Organization, foaf:Person,
	skos:Concept, swc:WorkshopEvent ; ] ;
	(c) SWDF classes summary

ds:objAuthority <http://dbpedia.org>, ...] ; ds:capability [ ds:predicate swc:hasLocation ; ds:sbjAuthority <http://data.semanticweb.org>; ds:objAuthority <http://data.semanticweb.org>, <http://dbpedia.org> ; ] ; ds:capability [ ds:predicate swrc:author ; ds:sbjAuthority <http://data.semanticweb.org> ; ds:objAuthority <http://data.semanticweb.org> ; ] ; ds:capability [ ds:predicate foaf:maker ; ds:sbjAuthority <http://data.semanticweb.org> ; ds:objAuthority <http://data.semanticweb.org> ; ] ; ds:capability [ ds:predicate swrc:abstract ; ds:sbjAuthority <http://data.semanticweb.org> ; ] ; ds:capability [ ds:predicate skos:prefLabel ; ds:sbjAuthority <http://dbpedia.org>, ...] ; ds:sbjAuthority <http://dbpedia.org> ; ds:objAuthority <http://upload.wikimedia.org> ; ] ; ds:capability [ ds:predicate foaf:depiction ; ds:sbjAuthority <http://dbpedia.org> ; ds:objAuthority <http://upload.wikimedia.org> ; ] ; ds:capability [ ds:predicate dbpedia2:party ; ds:sbjAuthority <http://dbpedia.org> ; ds:objAuthority <http://dbpedia.org>, <http://www.xat.org> ; ] ; (b) DBpedia data summary [] a ds:Service ; ds:url <http://swdf-2012> ; ds:capability [ predicate: foaf:based_near ; sbjClasses: foaf:Person, ...] ; objClasses: dbo...] ; ds:capability [ ds:predicate: owl:sameAs ; objClasses: dbo:Person, dbo:Scientist, ...

dbo:Country, dbo:Place, dbo:PopulatedPlace,

...] ; objClasses: dbo:City, dbo:Place, dbo:PopulatedPlace, ...] ; ds:capability [ ds:predicate: dbo:birthDate ; sbjClasses: dbo:Person,dbo:Scientist, ...] ; ds:capability [ ds:predicate: dbo:abstract ; sbjClasses: foaf:Person, dbo:Ship, ...] ; (d) DBpedia classes summary Fig. 3: Sample of authorities and classes summaries of logs of SWDF and DBpedia Definition 1 (Authority Capability). Given a source d, an authority capability is a triple (p, SA(d, p), OA(d, p)), which contains (1) a predicate p in d, (2) the set SA(d, p) of all distinct subject authorities of p in d and (3) the set OA(d, p) of all distinct object authorities of p in d.

Table 1 :

 1 All substitution values possible to create path join. ?x, ?y are variables and a, b are constants (URIs or literals)

	tp1 object tp2 subject substitution value
	?x	?y	?x
	?x	a	a
	a	?x	a
	a	b	null

  as in figure2, Q1S1D = Q1S Q1D.-If Q 1 contains binary operators like UNION or OPTIONAL, we distinct two cases:• If a joinable predicate is outside binary clauses of Q 1 , we add Q 2 in the BGP part of Q 1 . • If a joinable predicate of Q 1 is inside the UNION or OPTIONAL clauses,we append Q 2 inside this clause after the substitution of the join variables (subject or object of the triple) according to table1. -If a joinable predicate of Q 2 is inside an OPTIONAL clause, we make sure to not generate non well designed queries like query shown in 7c.

Table 2 :

 2 Do authorities summaries prune non joinable predicates? Do classes summaries prune further non joinable predicates? Does PFed able to generate plausible federated queries?All data, codes, and generated query are available at the project web page7 . Real Datasets and real logs We use SWDF 2012 and DBPedia 3.5.1 datasets and clean queries of Feasible 8 . We use only SELECT queries to construct plausible federated queries. Table2reports statistics about the datasets and query logs. It is strange that the query log of SWDF contains more predicates than the original dataset hosted at the SPARQL endpoint. Some queries in the logs use predicates that are not defined in the dataset. As they appear inside OPTIONAL or UNION, they do not stop queries from returning results. Using DBpedia to generate plausible federated queries is challenging because DBpedia dataset has a high number of predicates and the log of DBpedia has a high number of queries.

	dataset	|triples| |dataset predicates| |original log| |SELECT queries| |log predicates|
	SWDF	242 256	170	64 030	37 592	201
	DBPedia 232 542 405	39 672	217 812	127 812	247
	4.1 Experimental Setup
	Dataset and Queries:

Table 3 :

 3 Logs pruning using authorities summariesDo authorities summaries prune non joinable predicates ? Table3presents the results of pruning using authorities summaries. As we can see, the reduction is 62.75% for SWDF query log for path-shaped queries (all path refers to path from SWDF to DBpedia) and by 42.82% for star-shaped. The reduction is only 2.15% for DBpedia log for both path-shaped queries and star-shaped generation. This reduction is not significant because most of predicates in DBPedia has the authority <http://dbpedia.org>.

			path-shaped			star-shaped
	dataset |predicate joinable | |pruned log| % reduce |predicate joinable | |pruned log| % reduce
	SWDF	3	9 355	75.12	3	21 495	42.82
	DBPedia	139	36 522	71.42	83	36 449	71.48

Table 4 :

 4 Logs pruning using authorities and classes summariesDo classes summaries prune further non joinable predicates?We now use our classes summaries on top of authorities summaries. We observe in Table4that the sizes of logs are reduced. The reduction is impressive for DBpedia, it is about 72 %. Therefore, classes summaries are affective for pruning non joinable queries.

Table 5 :

 5 Number of PFed min generated using Authorities and Classes summaries

	p1	|p1|	p2	|p2| |PFed| |with result| %
	PFed path foaf:based_near 9 dbpedia2:capital 5	24	19	79.17
	PFed star skos:prefLabel 3 dbo:thumbnail 14	42	14	33.33

Table 6 :

 6 PFed path and star, p 1 ∈ SWDF and p 2 ∈ DBPedia Does PFed generate plausible federated queries ? Due to the size of the pruned logs, we can generate a large number of plausible federated queries. In our experimentation, we focus on the generation of path-shaped between foaf:based_near from SWDF and dbpedia2:capital from DBPedia. The pruned SWDF query log contains 2 866 queries that contains foaf:based_near. Many of these queries have the same structure but with different literals and variables. Therefore, instead of producing 2866 × 14 = 40124 queries where 14 is the number of queries that contains dbpedia2:capital in pruned DBpedia log, we define patterns for foaf:based_near queries. We differentiate 9 patterns for foaf:based_near queries and we generate 24 queries. All generated queries are executed correctly and 19 of these queries have non empty results set (see table6).

https://www.w3.org/TR/void

http://sparqles.ai.wu.ac.at/

URI Syntax Components: https://tools.ietf.org/pdf/rfc3986.pdf

https://github.com/GDD-Nantes/PFed

https://github.com/dice-group/feasible

Acknowledgement

This work is part of the multidisciplinary project Sedela, funded by CominLabs, that brings together three laboratories: LS2N, CREAD and Lab-STICC.

All information about logs, and prefixes are available at the project site: https: //github.com/GDD-Nantes/PFed

Pruning query logs

Based on authorities summaries and classes summaries, we can prune the logs of corresponding datasets by retaining only joinable queries.


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Kévin

Vocal flexibility in nonhuman primates and the origins of human language Flexibilité vocale chez les primates non-humains et origines du langage humain

Remeuf, Ludivine Glas). Research programs received financial support from the Japan Society for the Promotion of Science ("Postdoctoral Fellowship for Overseas Researchers" and "Young Researcher Overseas Visits" programs), the French Ministries of Foreign Affairs and of Higher Education and Research (Partenariat Hubert Curien "Sakura"), as well as the French National Centre for Scientific Research ("Projet International de Coopération Scientifique").

Below, we first review the theoretical framework of research on vocal communication in nonhuman primates and its impact on the debate about the origins of human language, with illustrations from lab and field studies conducted independently by Masataka and Lemasson, and their colleagues. We then present our common research achievements along three axes: vocal flexibility under social influences in adults, vocal development in juveniles, and perceptual abilities.

2 Theoretical research framework: Separate contributions of the French and Japanese teams Language plays a pivotal role in human societies, and the question of its origins is a hotly debated topic. Like any complex biological trait, it is unlikely to have evolved de novo, and it probably has a long evolutionary history. However, it is nearly impossible to find direct fossil-based evidence of the evolutionary path of language properties because they are of a behavioural nature. One alternative way to address this question is to examine the anatomical features, communicative mechanisms and cognitive abilities of humans compared to those of more or less phylogenetically related animals. Nonhuman primates, our closest relatives, are prime candidates for such a comparative approach. To look for the roots of human language, which is primarily of an acoustic nature with a social function, it is valuable to investigate the characteristics of vocal communication in nonhuman primates and the underlying cognitive and social mechanisms; this is the approach taken by both Masataka's and Lemasson's teams.

However, a few decades ago, the classic way to think of nonhuman primates' vocalizations was to consider them as reflex-driven expressions of the caller's internal state [START_REF] Jürgens | Neuronal control of vocal production in nonhuman and human primates[END_REF]. Both our teams have conducted studies confirming the acoustic encoding of arousal, a phenomenon also described in humans [START_REF] Breitenstein | The contribution of speech rate and pitch variation to the perception of vocal emotions in a German and an American sample[END_REF]. For example, in squirrel monkeys, isolation calls given by all group members have a longer duration when infants are separated further away from their natal group [START_REF] Masataka | Effect of separation distance on isolation call structure in squirrel monkeys (Saimiri sciureus)[END_REF]. Similarly, in three species of Old World monkeys, a separation-reunion experimental paradigm provided evidence of affect-induced changes in the use of contact calls (higher call rates) and their structure (longer and higherpitched calls) [START_REF] Lemasson | Cross-taxa similarities in affectinduced changes of vocal behavior and voice in arboreal monkeys[END_REF]. But we now know that this is only part of the range of messages encoded acoustically, and that nonhuman primates have some degree of control over their vocal production. In line with this, studies using operant conditioning experiments and vocal adjustment during helium exposure have shown that whitehanded gibbons can control their call emission and structure [START_REF] Koda | Experimental evidence for the volitional control of vocal production in an immature gibbon[END_REF][START_REF] Koda | Soprano singing in gibbons[END_REF]. Some nonhuman primates' calls also function as referential signals conveying information about external stimuli, a function analogous to semantics in human language. In Goeldi's marmosets, the acoustic structure of alarm calls provides reliable information about predator type (aerial versus terrestrial); this is used by listeners to

Vocal flexibility in nonhuman primates and the origins of human language Revue de primatologie, 7 | 2016 decide whether to climb down and freeze (aerial danger) or to climb up and respond with warning calls (terrestrial danger) [START_REF] Masataka | Categorical responses to natural and synthesized alarm calls in Goeldi's monkey (Callimico goeldii)[END_REF]. In Campbell's monkey males, alarm calls are produced in complex sequences whose composition (call types and order of call delivery) and rhythm of emission, as well as the acoustic structure of the calls itself (temporal and frequency parameters), encode information about the type of danger (e.g. tree fall, intergroup encounter, predator encounter and whether it is aerial or terrestrial) and the level of urgency (Ouattara et al., 2009a(Ouattara et al., , 2009b;;Lemasson et al., 2010c). By analysing the multi-level structure of monkeys' vocal emissions, these latter studies even revealed call combinations akin to affixation and syntax in human language [START_REF] Zuberbühler | Primate communication: Meaning from strings of calls[END_REF][START_REF] Coye | Suffixation influences receivers' behaviour in non-human primates[END_REF]. Also, by comparing populations living in habitats with different predator pressures, "lexical" dialects were found [START_REF] Schlenker | Monkey semantics: Two 'dialects' of Campbell's monkey alarm calls[END_REF].

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The parallel with human language goes even further, with clear demonstrations of acoustic plasticity. In several primate species, contact calls have been found to function as "social badges". For example, acoustic analyses of contact coo calls in Japanese macaques revealed habitat-related population differences [START_REF] Sugiura | Sound transmission in the habitats of Japanese macaques and its possible effect on population differences in coo calls[END_REF], sociallydriven "phonological" dialects [START_REF] Tanaka | Cross-sectional and longitudinal studies of the development of group differences in acoustic features of coo calls in two groups of Japanese macaques[END_REF], and individual identity coding [START_REF] Ceugniet | Vocal individual discrimination in Japanese monkeys[END_REF]. In Campbell's monkeys, females produce several variants of their contact CH (combined harmonic) calls, some of which are shared by close affiliative partners [START_REF] Lemasson | Patterns of vocal sharing and social dynamics in a captive group of Campbell's monkeys (Cercopithecus campbelli campbelli)[END_REF]. This remarkable phenomenon is dynamic (long term vocal convergence), as vocal sharing parallels the changes in social networks over time [START_REF] Lemasson | Patterns of vocal sharing and social dynamics in a captive group of Campbell's monkeys (Cercopithecus campbelli campbelli)[END_REF]Lemasson et al., 2011b). Interestingly, by screening the entire vocal repertoire of Campbell's monkeys and other Old World species (red-capped mangabeys and De Brazza's monkeys), identity coding has been found to be more reliable in calls mediating inter-individual social interactions (e.g. contact calls) than in socially less-targeted calls (e.g. food calls, alarm calls) [START_REF] Lemasson | Acoustic variability and social significance of calls in female Campbell's monkeys (Cercopithecus campbelli campbelli)[END_REF]Bouchet et al., 2012bBouchet et al., , 2013a)). Identity coding is thus call type-dependent, but also varies with the context. For instance, Diana monkeys produce more stereotyped (individually distinctive) calls when travelling in dark compared with bright habitats, to facilitate spatial cohesion in the forest [START_REF] Candiotti | Convergence and divergence in Diana monkey vocalisations[END_REF]). An interesting parallel can be drawn with human language, as the amount of identity cues in speech is adjusted according to the audience design (vocal accommodation theory: [START_REF] Giles | Accommodation theory: Communication, context, and consequence[END_REF].

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The inter-individual (social interaction) level of analysis has also revealed some interesting parallels with human language. Vocal exchanges in nonhuman primates have been found to resemble primitive forms of conversations, as they follow a number of interaction rules that are universal across human cultures [START_REF] Sugiura | Temporal and acoustic flexibility in vocal exchanges of coo calls in Japanese macaques (Macaca fuscata)[END_REF][START_REF] Henry | Social coordination in animal vocal interactions. Is there any evidence of turn-taking? The starling as an animal model[END_REF]. For example, Campbell's monkeys, Japanese macaques and marmosets respect a minimum and maximum inter-speech delay (to avoid calling simultaneously and ensure the continuance of the interaction) as well as a turn-taking principle (i.e. the two interlocutors alternate their calls) [START_REF] Sugiura | Temporal and acoustic flexibility in vocal exchanges of coo calls in Japanese macaques (Macaca fuscata)[END_REF]Lemasson et al., 2010a; see also [START_REF] Takahashi | Coupled oscillator dynamics of vocal turntaking in monkeys[END_REF]. Interestingly, social factors influence the organisation of vocal exchanges: in Campbell's monkeys, elders are more likely to receive a vocal response (Lemasson et al., 2010a; see also for marmosets: [START_REF] Chen | Contact calls of common marmosets (Callithrix jacchus): Influence of age of caller on antiphonal calling and other vocal responses[END_REF], while in squirrel monkeys, closely-affiliated partners are preferred interlocutors [START_REF] Biben | Temporal and structural analysis of affiliative vocal exchanges in squirrel monkeys (Saimiri sciureus)[END_REF]. Nonhuman primates are even capable of elaboration and persistence (two markers of intentional communication in humans) to increase their chances of getting a vocal response [START_REF] Koda | Flexibility and context-sensitivity during the vocal exchange of coo calls in wild Japanese macaques (Macaca fuscata yakui)[END_REF]. They are also able to acoustically copy (immediate vocal convergence) their partner during a vocal exchange, by producing a response call that structurally matches the one produced by their interlocutor [START_REF] Sugiura | Matching of acoustic features during the vocal exchange of coo calls by Japanese macaques[END_REF]; this phenomenon of "call matching" has also been observed in Diana monkeys and chimpanzees [START_REF] Mitani | Social factors influence the acoustic variability in the long-distance calls of male chimpanzees[END_REF][START_REF] Candiotti | Convergence and divergence in Diana monkey vocalisations[END_REF].

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The above-mentioned studies relate to adult plasticity, but human language is socially learnt at very early stages of development. Since the earliest works in the 1970s and 1980s, vocal development in nonhuman primates has been considered to be under strong genetic control. Social deprivation, deafening, hybridizing, and infant cross-fostering experiments revealed that nonhuman primates possess adult calls since birth and that they display little to no acoustic variability throughout their life (see [START_REF] Hammerschmidt | Constraints in primate vocal production[END_REF], for a review). But more recently, technical progress in acoustic analyses and a renewal of interest in vocal variability revealed some degree of acoustic variability during development (see [START_REF] Snowdon | Plasticity of communication in nonhuman primates[END_REF], for a review), and even a remarkable phenomenon of babbling in marmosets [START_REF] Snowdon | Babbling'in pygmy marmosets: Development after infancy[END_REF].

In addition to the ontogeny of acoustic structure, a growing number of studies have provided evidence for social learning of the appropriate context of calling (see [START_REF] Seyfarth | Some general features of vocal development in nonhuman primates[END_REF][START_REF] Snowdon | Plasticity of communication in nonhuman primates[END_REF], for a review). For instance, any kind of flying object elicits an alarm call in young vervet monkeys, but through observation of adults' behaviour, they learn to become more selective and to use this call type only if they have spotted real aerial predators [START_REF] Seyfarth | Some general features of vocal development in nonhuman primates[END_REF]. In Japanese macaques, the appropriate use of greeting calls, notably the choice of specific receivers, is acquired in the course of development, probably under the social influence of group members [START_REF] Katsu | Development in the usage and comprehension of greeting calls in a free-ranging group of Japanese macaques (Macaca fuscata)[END_REF]. These studies have to some extent challenged the view of primate vocal behaviour as innate and inflexible, and they have highlighted the value of investigating vocal development in conjunction with the social environment.

To have a complete understanding of the mechanisms and functions underlying primate communication, as well as vocal production and usage, another important dimension to study is auditory perception. For a message to be conveyed, receivers must be able to discriminate between the fine acoustic variations described above. Thus, the cognitive abilities and neuropsychological mechanisms underlying nonhuman primates' perceptual capacities are an important area of research. Studies have provided evidence that various species of primates are able to perceive contextual variants and individual differences. For example, playback experiments have shown that monkeys, notably Japanese macaques, are able to discriminate between contextual variants of coo calls (Le [START_REF] Prell | Factors influencing the salience of temporal cues in the discrimination of synthetic Japanese monkey (Macaca fuscata) coo calls[END_REF], girneys [START_REF] Masataka | Motivational referents of contact calls in Japanese monkeys[END_REF] and screams (Le [START_REF] Prell | Discrete or graded variation within rhesus monkey screams? Psychophysical experiments on classification[END_REF], and that they are capable of vocal recognition of individuals (intra-group: Ceugniet and Izumi, 2004b;[START_REF] Lemasson | Friendships between males and lactating females in a free-ranging group of olive baboons (Papio hamadryas anubis): Evidence from playback experiments[END_REF]-inter-group: Briseño-Jaramillo et al., 2015-inter-species: Candiotti et al., 2013), including mother-offspring pairs [START_REF] Masataka | Development of vocal recognition of mothers in infant japanese macaques[END_REF][START_REF] Shizawa | Playback experiment to test maternal responses of Japanese macaques (Macaca fuscata) to their own infant's call when the infants were four to six months old[END_REF], and both maternal [START_REF] Rendall | Vocal recognition of individuals and kin in free-ranging rhesus monkeys[END_REF] and even paternal kin [START_REF] Pfefferle | Female rhesus macaques discriminate unfamiliar paternal sisters in playback experiments: Support for acoustic phenotype matching[END_REF]. Playback studies in different guenon species revealed that individual signatures are memorized for at least four years [START_REF] Lemasson | Socially meaningful vocal plasticity in adult Campbell's monkeys[END_REF] and that referential alarm calls are decoded at both conspecific and heterospecific levels [START_REF] Zuberbühler | Interspecies semantic communication in two forest primates[END_REF][START_REF] Coye | Suffixation influences receivers' behaviour in non-human primates[END_REF].

The assessment of nonhuman primates' perceptual abilities can provide insights regarding the evolutionary origin of language processing. For example, although the left cerebral hemisphere is known to play an essential role in the processing of speech in humans, there is also evidence of some task-sharing between the two hemispheres, with the left hemisphere specializing in processing of syntactic and semantic activities, and the right hemisphere attending preferentially to the prosody or novelty of a signal

Vocal flexibility in nonhuman primates and the origins of human language Revue de primatologie, 7 | 2016 [START_REF] Friederici | Lateralization of auditory language functions: A dynamic dual pathway model[END_REF]. No clear consensus about the phylogenetic origin of this hemispheric specialization has yet been reached, although there is some evidence for the importance of familiarity with the speaker as well as the emotional valence of the interaction on brain asymmetry in both human and nonhuman primates [START_REF] Basile | Social and emotional values of sounds influence human (Homo sapiens) and non-human primate (Cercopithecus campbelli) auditory laterality[END_REF].

3 Contributions of the France-Japan collaboration: A further step toward understanding primate communication

Vocal flexibility under social influences

To learn more about vocal flexibility in nonhuman primates, our teams have collaborated on two studies of the use of contact coo calls by adult Japanese macaques, with a special focus on the impact of the social characteristics of the caller and its interlocutor.

First, Lemasson and Masataka investigated sex differences in usage style of contact calls (Lemasson et al., 2013a). They studied a group containing 8 adult males and 18 adult females, housed at the Primate Research Institute (University of Kyoto). Adult females were found to be more vocally active than males, and they also contributed more frequently to conversation-like vocal exchanges respecting the turn-taking rule. Interestingly, age was an important parameter: older females received increasingly more vocal responses from other group members. In males, however, dominance rank was the determining factor influencing call usage style, with lower-ranking males producing more repeated (juvenile-like) sequences than higher-ranking males.

Sex differences in nonhuman primates' calls can take the form of acoustic discrepancy (e.g. lower-pitched and longer calls in males) mostly related to differences in size and body weight [START_REF] Ey | Do age-and sex-related variations reliably reflect body size in non-human primate vocalizations? A review[END_REF]. But differences in call usage (e.g. higher call rates, preferential usage of certain call types) are thought to be related to sex-specific social roles [START_REF] Bouchet | Sex differences in the vocal repertoire of adult red-capped mangabeys (Cercocebus torquatus): A multi-level acoustic analysis[END_REF](Bouchet et al., , 2012a)). Females form the social core of the group in Japanese macaques, notably because they do not emigrate at puberty [START_REF] Nakamichi | Lifetime social development in female Japanese macaques[END_REF]. They are thus often involved in mediation of intra-group social relationships, hence the frequent use of affiliative calls especially within socially ruled vocal exchanges. In addition, the order of participation within a vocal exchange is age-dependent, elders coming first, a pattern already known for other monkeys and in the conversations of most traditional oral, and some modern, human societies (Lemasson et al., 2010a). Age is socially important in Japanese macaques, with older matriarchs possessing a particular social status [START_REF] Nakamichi | Lifetime social development in female Japanese macaques[END_REF]. Males, by contrast, are more socially peripheral, acting mostly as group protectors and playing a role in social vigilance and inter-group spacing, hence the lesser use of social calls. Their hierarchical rank is nevertheless a critical determinant of their position, with dominant males being more integrated within the troop [START_REF] Horiuchi | Affiliative relations among male Japanese macaques (Macaca fuscata yakui) within and outside a troop on Yakushima Island[END_REF]. Interestingly, conversely to females, whose dominance rank is stable as it is determined by age and kinship [START_REF] Nakamichi | Lifetime social development in female Japanese macaques[END_REF], male inter-troop transfers cause frequent rank changes among resident males [START_REF] Suzuki | Intertroop transfer and dominance rank structure of nonnatal male Japanese macaques in Yakushima, Japan[END_REF].

A subsequent study asked whether vocal exchanges might parallel the social network, given that affiliative calls are used in mediating social interactions [START_REF] Arlet | Grooming-at-a-distance by exchanging calls in nonhuman primates[END_REF]. Two

Vocal flexibility in nonhuman primates and the origins of human language Revue de primatologie, 7 | 2016 captive groups of Japanese macaques were studied, including 17 and 28 adult females respectively, housed at the Primate Research Institute in two very different enclosures (one relatively small with open visibility, and one large and forested). We tested whether affiliative relationships (measured through dyadic spatial proximity and grooming scores), kinship, dominance rank and age differences could predict the distribution of dyadic vocal exchanges. We found that contact call rates between two given females correlated only with the time spent grooming each other, regardless of the group. Interestingly, contact calls were mostly exchanged between females when they were distant from each other. Lastly, dyads presenting a higher level of grooming reciprocity also initiated vocal exchanges in a more balanced way.

These findings support the idea that social factors outweigh environmental factors in explaining flexibility in social call usage. Furthermore, this study provided empirical evidence for the predictions of the social bonding hypothesis developed by [START_REF] Dunbar | Grooming, gossip, and the evolution of language[END_REF]. This theory argues that vocal exchange rates evolved together with group size in primates, in order to facilitate the maintenance of cohesion between spatially-distant affiliated partners. Thus, once it became impossible to allocate enough time to physically interact with all affiliated group members, vocalizations replaced manual grooming as a form of "vocal grooming-at-a-distance", a step towards the emergence of conversations in the primate lineage.

Vocal development

The existence of vocal flexibility in adult nonhuman primates raises questions about how this variability emerges during ontogeny; there is a need for more studies in this domain. Our teams have collaborated on four studies investigating various aspects of vocal development in three nonhuman primate species.

One study, conducted at the Primate Research Institute, investigated the development of contact call use in Japanese macaques (Lemasson et al., 2013a). This study (already mentioned above) provided evidence of sex differences in vocal usage in adults. However, observations of 10 juveniles (5 males, 5 females, average age: 8-10 months old) revealed no sex differences at this early age. Overall, juveniles differed from adults by their higher overall vocal activity, and by their production of similar rates of isolated calls, repeated sequences (the same individual calls several times in a row) and exchange sequences (the individual responds vocally to or receives a response from a group member); adults, by contrast, called mostly within temporally ruled vocal exchanges. Also, when juveniles contributed to vocal exchanges, they respected the turn-taking rule far less than adults.

Higher levels of vocal activity and absence of sex differences in juveniles have also been observed in other species, for example De Brazza's monkeys (Bouchet et al., 2012a). This suggests that appropriate use of calls emerges through experience and social integration. As they grow older, individuals acquire more distinct social roles [START_REF] Eaton | Development in Japanese macaques (Macaca fuscata): Sexually dimorphic behavior during the first year of life[END_REF] and their vocal activity evolves accordingly. This process is hypothesized to be based on social learning from same-sex adult models. Our findings add to the growing literature showing that juveniles learn appropriate contexts of call emission from adults [START_REF] Seyfarth | Some general features of vocal development in nonhuman primates[END_REF][START_REF] Snowdon | Affiliative processes and vocal development[END_REF][START_REF] Roush | Food transfer and development of feeding behavior and foodassociated vocalizations in cotton-top tamarins[END_REF].

A second study focused on the turn-taking rule in another monkey species, again by comparing the appropriateness of call patterns between adults and juveniles, and also by testing the cognitive relevance of this rule in both age-classes [START_REF] Lemasson | Youngsters do not pay attention to conversational rules: Is this so for nonhuman primates[END_REF].

Vocal flexibility in nonhuman primates and the origins of human language Revue de primatologie, 7 | 2016 Observations of 7 adult females and 7 youngsters, housed at the Station Biologique de Paimpont (University of Rennes 1), revealed that juveniles spontaneously break the turntaking rule twelve times more often than adults. Furthermore, playback experiments showed that adult females discriminated between call exchanges that respected the turntaking between callers and those that did not, whereas youngsters did not.

In a third study, using similar playback experiments based on the violation-ofexpectation paradigm, Bouchet et al. (2013b) tested whether adult and juvenile Japanese macaques equally paid attention to the call-matching rule. As mentioned earlier, during vocal exchanges, adult female Japanese macaques acoustically copy their partner's calls [START_REF] Sugiura | Matching of acoustic features during the vocal exchange of coo calls by Japanese macaques[END_REF]. Observations revealed that sub-adults (aged 3-5 years old) were less efficient than adults at respecting the call-matching rule [START_REF] Sugiura | Matching of acoustic features during the vocal exchange of coo calls by Japanese macaques[END_REF][START_REF] Masataka | The onset of language[END_REF]. Here, we tested the ability of 10 adult females and 10 one-year-old females, housed at the Primate Research Institute, to discriminate between vocal exchanges that respected the call-matching rule or not. Again, only adults displayed different levels of interest for the two types of stimuli. All of the above findings suggest that experience and social learning are involved in the emergence of different conversational rules. In fact, a recent study in marmosets provided empirical evidence that the turn-taking rule is learned during ontogeny under adult tutoring: adults reinforced their offspring by responding to calls that followed the species-typical temporal pattern, but remained silent following interrupted calls [START_REF] Chow | Vocal turn-taking in a non-human primate is learned during ontogeny[END_REF]. Interestingly, in human infants too, turn-taking and vocal imitation improve within the first few months of life, supported by feedback from the mother during vocal interactions [START_REF] Masataka | Early ontogeny of vocal behavior of Japanese infants in response to maternal speech[END_REF][START_REF] Masataka | Effects of contingent and noncontingent maternal stimulation on the vocal behaviour of three-to four-month-old Japanese infants[END_REF][START_REF] Masataka | The onset of language[END_REF].

Finally, to better our understanding of maternal roles in monogamous primates, Koda and Lemasson investigated the development of wild gibbons' singing behaviour based on field data collected in Sumatra (Indonesia) (Koda et al., 2013b). Pairs of adult gibbons produce complex duets during which male and female sing synchronously. As part of those duets, adult females produce great calls which are individually distinctive [START_REF] Oyakawa | Acoustic features contributing to the individuality of wild agile gibbon (Hylobates agilis agilis) songs[END_REF]. Juveniles do not produce adult-like great calls, but sub-adult daughters are regularly involved in synchronized and overlapping great call interactions with their mother. We observed 6 female agile gibbons and their sub-adult daughters at different stages of development (inferred from co-singing rates). First, we found acoustic matching between mothers and daughters at the time of co-singing, which suggests abilities in immediate copying. Second, mothers were found to produce songs in a more stereotyped manner during mother-daughter interactions, especially at early stages of development, possibly to facilitate synchronization and their daughters' learning of the appropriate acoustic structure. Lastly, during development, the degree of acoustic resemblance between mother (but not other adult females) and daughter increases, along with the precision of synchronization in the duet.

This study provides evidence of a complex mechanism of song acquisition in sub-adult female gibbons, and highlights the maternal influence on offspring vocal development. Empirical evidence of social learning under parental influences and maternal tutoring is still very scarce. A recent study in marmosets demonstrated that infant calls undergo dramatic changes during the first two months of life, transforming from cries into mature adult-like phee calls. The timing of this transition was partly attributable to maturation but was also strongly influenced by contingent parental vocal feedback [START_REF] Takahashi | The developmental dynamics of marmoset monkey vocal production[END_REF].

Vocal flexibility in nonhuman primates and the origins of human language Revue de primatologie, 7 | 2016

Perceptual abilities

To know whether the acoustic variability observed is salient for the nonhuman primates themselves requires experiments. Playback experiments offer the possibility to investigate which characteristics of the acoustic stimuli subjects are sensitive to. Masataka's and Lemasson's teams have conducted two studies on the relevance of social and non-social acoustic stimuli in Japanese macaques and Campbell's monkeys, as well as a study testing for the pertinence of social visual stimuli in the same two species.

One study was conducted to explore the effects of sound specificity and familiarity on auditory laterality in Japanese macaques (Lemasson et al., 2010b). Six adult females, housed at the Primate Research Institute, heard 10 categories of familiar and non-familiar nonhuman primate contact calls (familiar: calls of chimpanzees and gibbons housed at the same facility versus unfamiliar: calls of Campbell's monkeys, De Brazza's monkeys and red-capped mangabeys housed at the Station Biologique de Paimpont), bird calls (familiar: Japanese crows versus unfamiliar: French geese), and non-biological sounds (familiar: sound of pellets being poured into a bucket versus unfamiliar: piano melodies). Interestingly, familiarity, and not specificity, influenced auditory laterality but only for nonhuman primate calls, and not for other types of sounds. Experiments using the headturn paradigm revealed a left-side head orientation (i.e. right cerebral hemisphere processing) bias at the group level for familiar nonhuman primates of the same or other species.

This finding confirms that the left-hemisphere dominance for communication processing in the primate lineage may have been over-emphasized, and that more studies investigating task-sharing between hemispheres are needed, "social" familiarity between interlocutors being an important factor to take into account. This finding also suggests that individual recognition is possible at the heterospecific level (see also [START_REF] Candiotti | Voice discrimination in four primates[END_REF], a potentially important ability for primates that share habitats with other species.

A second study asked whether there was a preference for consonant over dissonant sounds in Campbell's monkeys (Koda et al., 2013a). An earlier study showed that Japanese macaques were able to discriminate between consonant and dissonant chords [START_REF] Izumi | Japanese monkeys perceive sensory consonance of chords[END_REF]. The distribution of this perceptual ability across the primate lineage is particularly interesting for unravelling the phylogenetic origin of musicality in humans, who spontaneously prefer consonant over dissonant sounds from early infancy [START_REF] Zentner | Infants' perception of consonance and dissonance in music[END_REF]. Musical ability, and the underlying cognitive mechanisms, have been hypothesized to constitute an intermediate stage in the evolution of language in the order Primates [START_REF] Masataka | Music, evolution and language[END_REF][START_REF] Masataka | The origins of language and the evolution of music: A comparative perspective[END_REF]. In our study, 6 adult female Campbell's monkeys, housed at the Station Biologique de Paimpont, were tested in an experimental paradigm that enabled monkeys to express their auditory preferences. We applied a sensory reinforcement paradigm based on the spontaneous spatial positioning of the subject, free to move in its habitual enclosure, which was divided into two identical sections. As soon as the monkey moved to one side, the corresponding loudspeaker played one of the paired-comparison sounds until the monkey crossed the central line and moved to the other side, resulting in the other paired-comparison sound being immediately broadcast from the opposite speaker. Monkeys showed no preference for consonant over dissonant stimuli, even though the experimental paradigm was verified as monkeys displayed a preference for soft over loud white-noise control stimuli.

Vocal flexibility in nonhuman primates and the origins of human language Revue de primatologie, 7 | 2016

In another study using the same experimental paradigm, tamarins did not show any preference for consonant chords [START_REF] Mcdermott | Are consonant intervals music to their ears? Spontaneous acoustic preferences in a nonhuman primate[END_REF]. Only one human-reared infant chimpanzee has been reported to exhibit this preference [START_REF] Sugimoto | Preference for consonant music over dissonant music by an infant chimpanzee[END_REF]; enculturation and previous experience of hearing music may account for its peculiar sensitivity to consonance. As very few music-based studies have been conducted comparing human and nonhuman primates, at present it is possible to conclude only that sensitivity to musical harmony has not been established in the latter; further investigations are needed.

Lastly, on a topic unrelated to the evolution of language but related to sensory and social preferences, our teams conducted a study of visual recognition of age-class and preference for infantile features in two species of Old World monkeys [START_REF] Sato | Visual recognition of age class and preference for infantile features: Implications for species-specific vs universal cognitive traits in primates[END_REF]. In humans, infantile features are innately perceived as cute [START_REF] Sanefuji | Development of preference for baby faces across species in humans (Homo sapiens)[END_REF]; it is thought that attraction to "babyness" motivates caretaking behaviour. We tested 11 female Japanese macaques housed at the Primate Research Institute and 10 female Campbell's monkeys housed at the Station Biologique de Paimpont. Visual paired comparison tasks were conducted to test for the ability to discriminate between infant and adult images (of Japanese macaques) of their own species (Japanese macaque subjects) or of another species (Campbell's monkey subjects). Japanese macaques strongly discriminated, exhibiting a preference for infant over adult images. At the heterospecific level, Campbell's monkeys produced a weaker response, but still looked longer at infant versus adult images of Japanese macaques, suggesting that the attractiveness of infant images transcends species differences.

Nonhuman primate societies, like human society, are based on complex interactions between individuals who differ in their social roles. Age is a key determinant of social status, thus visual recognition of age-class, as with the perception of identity cues in vocal signals, might be critical for social group functioning. Humans can perceive not only conspecific but also heterospecific "babyness" [START_REF] Sanefuji | Development of preference for baby faces across species in humans (Homo sapiens)[END_REF]. Our study provides evidence that this may also be the case in nonhuman primates, although additional studies in a wider range of species are needed.

Conclusion

The France-Japan collaboration has enabled both our teams to share their knowledge of experimental paradigms and some methodological (e.g. acoustic analysis) tools, to get access to research facilities for primate behaviour studies in each country, and to conduct comparative studies on a wide range of socially varied primate species. Together, Masataka's and Lemasson's teams have contributed significantly to the current debate about vocal flexibility in nonhuman primates and the evolutionary origins of human language. Their studies highlight the critical influence of social factors on the emergence of acoustic variability in nonhuman primates with some key results as follows: 1) vocal activity is determined by the subject's social status within the group; 2) the network of vocal exchanges parallels the network of affiliative interactions; 3) the appropriate acoustic structure of calls and the appropriate context of calling are to some extent subject to social learning; 4) parental feedback shapes offspring vocal ontogeny; 5) perceptual abilities for discriminating between various social acoustic and visual stimuli are related to social functioning and experience.

Vocal flexibility in nonhuman primates and the origins of human language Revue de primatologie, 7 | 2016 34 Over the years, our teams have gained extended knowledge, from both field and captive studies, about the communicative behaviour of two species notably: the Japanese macaque, a species endemic to Japan that lives in large multi-male multi-female groups, and the Campbell's monkey, an African guenon species that lives in harems. Comparative studies in these two, now well-known, key species whose social systems differ might allow us to further test the hypothesis of a co-evolution between social life and communicative abilities in the primate lineage [START_REF] Dunbar | Grooming, gossip, and the evolution of language[END_REF][START_REF] Masataka | The origins of language. Unraveling evolutionary forces[END_REF][START_REF] Lemasson | What can forest guenons 'tell' us about the origin of language? In Primate Communication and Human Language: Vocalisation, Gestures, Imitation and Deixis in Humans and Non-Humans[END_REF]. This opens new lines of investigation regarding the factors which led to the emergence of the highly complex communication system that is human language [START_REF] Zuberbühler | The primate roots of human language. In Becoming Eloquent: Advances in the Emergence of Language, Human Cognition, and Modern Cultures[END_REF]Lemasson et al., 2013b;Bouchet et al., 2016).

The collaboration started when Lemasson was hosted by Masataka as a post-doctoral fellow at the Primate Research Institute in Japan in


Christelle Dodane

Dominique Boutet

Ivana Didirkova

Fabrice Hirsch

Slim Ouni

Aliyah Morgenstern

An integrative platform to capture the orchestration of gesture and speech

ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Introduction

According to Bolinger (1983: 157), "we READ intonation the same way we read gestures". In parallel with Darwin's observations about gestures (1872), intonation is iconic in the sense that the meaning of upward and downward movements is related to attitudes and indirectly to metaphorical associations with tension, incompleteness and their opposites. Intonation has its own "symbolizing power thanks to a primitive drive mechanism that raises pitch as tension rises and lowers it as tension falls" (Bolinger, 1983: 156). It is part of our body movements which are more or less automatically concomitant to our state and our emotions. Bolinger highlights that gestures are coupled with intonation and display the same ascending and descending movements. Gesture and intonation may not systematically be produced together, but when they are, they are synchronized and co-expressive. Their synchrony does not necessarily mean that they work in unison, but rather that the parallel movements are coupled while the non-parallel movements are not. Several other authors have also noted a synchronization between the speech flow and the gestural flow. Kendon (1980: 211) states that "it is as if the speech production process is manifested in two forms of activity simultaneously: in the vocal organs and also in bodily movement". For example, the gestural stroke aligns temporarily with the specific linguistic segments that are co-expressive with it [START_REF] Mcneill | Hand and Mind. What Gestures Reveal about Thought[END_REF]. For these authors, gestures and speech are part of the same system. We also know that multimodal processes appear early on during language development, since canonical babbling is linked to the rhythmic and manual activities of babies [START_REF] Locke | Emergent control of manual and vocal-motor activity in relation to the development of speech[END_REF]. In adults, speech is often accompanied by gestures [START_REF] Guellaï | Prosody in the hands of the speaker[END_REF] and even congenital blind people gesture when interacting [START_REF] Iverson | Why people gesture when they speak[END_REF]. Adult speakers coordinate their gestural behaviors and intonation when they speak, both in terms of time and direction: downward / forward movements are typically produced with descending contours and upward / backward movements with ascending contours [START_REF] Bolinger | Intonation and gesture[END_REF][START_REF] Cruttenden | Intonation[END_REF]. [START_REF] Balog | The relationship between early gestures and intonation[END_REF] observed the same type of synchronization in children aged 12 to 24 months and showed that children coordinate their verbal and non-verbal behaviors at the temporal and directional levels as early as the first word period, in order to be better understood by those around them. In their study, gesture coding was done by hand by observers who used a video in slow-motion and they had to indicate whether there was synchronization with the intonation or not. Using motion capture (OptiTrak recordings) on ten speakers, [START_REF] Roustan | Co-production of contrastive prosodic focus and manual gestures: temporal coordination and effects on the acoustic and articulatory correlates of focus[END_REF] showed that the prosodic focus attracts the manual gestures (pointing, beat and control gestures), pointing gestures being the most synchronized gestures (mainly between the apex of the pointing gesture and articulatory vocalic targets). These studies indicate that it is crucial to work on the synchronization of prosody and gestural behaviors, in adults as well as children. In order to achieve that goal, the MODALISA team has planned to create a multimodal platform that will make it possible to analyze prosody and gesture together. Indeed, to our knowledge, there is no adequate instrument that makes it easy to measure gestures and prosody together. The objective of the MODALISA1 project is thus to create an integrative procedure with the existing tools, that would make it possible to align the acoustic data with the gestural data. Instead of manual coding, we aim to use automatic extractions of the different gestural components (movements of the hands, forearms and arms) using several motion capture systems. The original contribution of our project is that we use the gestural data complemented with articulatory and respiratory data obtained with other devices (laryngograph, articulograph, abdominal belt). This set-up allows us to create a truly multimodal platform for the simultaneous study of speech and gesture. It gives us access to objective, accurate and reliable data that will allow us to develop a large number of studies on speech and gesture. This paper presents our pilot study with the integrative system, our methodological procedure, preliminary results and perspectives.

Methods of data acquisition, annotation and analysis

For our pilot study, we implemented and tested the whole multimodal procedurę on one participant.

Participant

A 33 years old French typical right-handed male speaker (MO1) was recorded in the premises of the LORIA laboratory in Nancy. The speaker had previously filled out a document asking for his consent indicating the different steps of the recordings and the equipment used.

Experimental paradigm

MO1 was recorded during a narrative task, in an experimental situation, inspired by McNeill's protocol (1992). Several sequences from a cartoon of the series Tweety and Sylvester (1949, Warner Brothers) were presented to him. After viewing each sequence, MO1 had to narrate it immediately to an interlocutor. MO1 was filmed throughout the duration of the task. We cut the cartoon into 5 sequences, including the "strike" sequence frequently exploited by the gesture community and which was chosen for this study in order to present the processing chain used to study the synchronization of gestures and prosody. For this short paper, we will focus on the acoustic data and on the gestural data exported from the IMU (Inertial Measurement Units, see just below).

Recording procedures

MO1 was recorded with two different motion capture devices (mocap). The first device (see Figure 1, left) consists of an electromagnetic articulograph (EMA) to record the movements of both hands and speech articulators (lips, tongue, jaw), a microphone to capture the acoustic signal and a video camera placed facing the speaker to film the entire scene. The device is completed by a laryngograph, which records the activity of vocal fold vibrations and a breathing belt recording the subject's abdominal movements. The EMA is normally used to study the movements of the main articulators of speech, i.e. the lips, tongue and jaw. The different movements are recorded every 5 ms using sensors placed on these different articulators. An electromagnetic field inducing an alternating current in the sensors makes it possible to measure the distance between the sensors and the transmitters (absolute measurement). We diverted it from its original use by placing 3 sensors on each hand (6 sensors in total) and 6 remaining sensors on the face and tongue (the device being equipped with 12 sensors in total). The sampling frequency of the EMA is 300 Hz and the recording of the speech signal (16 bits, 16 kHz) is synchronized with the recording of the magnetic signals provided by the sensors. The second device (see Figure 1, in the middle) is composed of a suit that forms a serie of Inertial Measurements Units (IMU) and captures the body's movements with 32 sensors located on the entire body (inertial units). The data is then visualized in 3D with the AXIS Neuron software (see Figure 1,right).

Coding and processing of acoustic and prosodic data

The sound files were segmented with the Praat software (Boersma & Weenink, 2018) and result in a 6line grid (called "tiers", see Figure 2). The "phoneme", "syllable" and "word" tiers, were automatically segmented with the EasyAlign software [START_REF] Goldman | EasyAlign: an automatic phonetic alignment tool under PraatProceedings of InterSpeech[END_REF] and then manually corrected. The following three tiers were annotated manually. The "Prom" tier includes the annotation of perceptual salient syllables (prominences) following the procedure recommended by the Rhapsodie ANR prosodic coding protocol [START_REF] Lacheret | Rhapsodie : un Treebank annoté pour l'étude de l'interface syntaxe-prosodie en français parlé. 4e Congrès Mondial de Linguistique Française[END_REF]. The strong prominences ("S") were coded by ear at a coding span of 5 seconds. Then the weak prominences ("W") were annotated. The prominences marked by a sharp rise in the fundamental frequency (F0) were annotated "S°°" or "W°°" and those marked by a smaller rise, "S°" and "W°". A fifth tier was added to manually annotate the different intervals corresponding to the points of inflection of the F0 and the value of the F0 corresponding to these points (upward contours, "M", downward contours, "D" and flat contours, " P "). And finally, a sixth tier was added containing the annotations of the different disfluencies, with the aim of comparing the disfluencies of stutterers and normo-fluent subjects, since one of the future applications of our project is the analysis of the coordination between gestures and speech in subjects who stutter. The evolution of the F0 value (in Hertz) was then extracted automatically with the Praat software (every 10 ms for the F0 and every 10.666 ms for the intensity) and imported into the ELAN software [START_REF] Sloetjes | Annotation by category -ELAN and ISO DCR[END_REF] to be synchronized with gestural data. To obtain a stylization of pitch variations according to a tonal perception model, we used the "Prosogram" application from Mertens (2019).

Figure 3: Prosogram of a statement produced by MO1, with in black, the automatic detection of the temporal evolution of pitch, and on the top, the targets in semitones.

Synchronisation of the recordings

The data retrieved from the three sources -video, audio, and motion capture (mocap) -had to be synchronized with each other since the recordings did not start at the same time. Synchronization was performed under ELAN in which we can integrate the audio, video and mocap sources (with a beep or manual clap at the beginning).

Sampling frequencies

In addition to synchronization, the frequency of each of these recordings is not the same, it is even different within the same audio source. Indeed, the sampling frequency of the pitch is 10 ms. In concrete terms, this means that the gap increases as time goes by. The sampling rate of the images in the video is 40 ms. The timespan in transcripts under ELAN or Praat is variable and can be done to the nearest millisecond. The timespan for the mocap (Inertial Movement Unit) is 16.5 ms. Four different frequencies coexist in the data, in increasing order: a millisecond for transcription under Praat and / or ELAN, 10 ms for the pitch, 16.5 ms for the mocap and finally the timespan of the video is 40 ms. Video serves us primarily as a visual synchronization element, the data are not processed on this visual basis. In any case, we quickly found gaps in the data. These gaps increase progressively, and vary according to the type of data. It was therefore necessary to re-sample continuously in order to calibrate and coordinate the data without creating false data.

Resampling method

As we wanted to avoid to create false data, by using interpolation for example, the principle of resampling consisted in aligning the data associated with a short timespan (10 ms) from the existing data associated with a longer span in frequency. Thus, the first four temporal values of the mocap (i / 0 ms, ii / 16.5 ms, iii / 33 ms, iv / 46.5 ms), were aligned with the pitch data associated with the first six values (i / 0 ms, iii / 20 ms, iv / 30 ms, vi / 50 ms).

Step by step, every 16.5 ms, the mocap data were compared with the pitch data that corresponded to the closest temporal values. When the matching by resampling of the pitch and mocap data were done, we needed to compare this re-alignment of the data with the Praat transcripts. Each unit (word, syllable, phoneme) has a beginning and an end. These intervals do not correspond to a fixed timespan, they depend entirely on what has been produced by the speaker. The temporal values of word boundaries can be corrected based on the closest values in the mocap output (values are inferior to 8.25 ms, ie 16.5 / 2). Table 1: measures based on the Prosogram application for the extract in which the motion capture was used along with the EMA and the IMU suit.

Results

All the studies that have so far explored the relationship between prosody and gestures have followed the positions and movements of the hand according to an absolute frame of reference. Among the sets of devices used in this study, the EMA falls under this type of absolute reference framework. In order to record the co-verbal gestures, these sensors are placed on the hands only, providing data on the position and movement of the hands in a unique and absolute reference frame being located in the recording room. Note that the hands may be submitted to a movement from higher up (arms, shoulders) without having moved on their own, i.e. the consequence of a movement of the arm is measurable on the hand. With a device like the EMA, one cannot detect and analyze the movements of the other segments nor the movement of the hand itself. Thus, to find out what the movements of all the segments of the upper limb are like, we can use the data from the IMU. The IMU enables us to situate the gestures in as many intrinsic reference frames as there are segments: the position and the movement of each segment are given with respect to the adjacent and proximal segment. Thus, the movements of the arm are calculated according to the shoulder, those of the forearm, according to the arm, those of the hand are determined relative to the forearm. It is therefore possible to measure which segment is moving and by which angle in the three dimensions of each one's own space. The results of the relations between prosody and gesture in these intrinsic frames of reference are presented below. We can thus follow the evolution of the pitch and its possible impact on one of the 8 degrees of freedom of the upper limb, distributed from shoulder to hand. To our knowledge, these links have never been made. A correlation (Bravais-Pearson) was established between the rising (N = 63; mean time = 90.40 ms) and descending (N = 111; mean time = 92.74 ms) ranges of F0 and the degrees of freedom of the three segments (arms, forearm and hand) of the right upper limb and shoulder for the IMU recording. The linear correlation coefficients range between 1 and -1. Notice that there is a strong affinity between two sets of variables when their value is between 0.8 and 1 or between -0.8 and -1. As we get closer to the value 0, the series are less, if at all, correlated. These results are presented in the two tables below. Tables 2 and3 indicate that the correlations between the variations of F0 and the degrees of freedom are very strong (at least 60% of the cases higher than a coefficient that is equal to or higher than || 0.8 ||). Moreover, these correlations distributed over all segments of the upper limb, are particularly important for the arm and decrease globally as we take the movement of the forearm and hand into consideration.

Even if the high correlation rate remains present for these latter segments, we notice a decrease in the co-variation with the pitch for the distal segments, in particular with a shift towards lower values (between 0.6 and 0.4). In other words, the further one gets away from the bust, in terms of segments (and not of distance), the less powerful this co-variation becomes. We don't know yet whether this anisotropy is structural or if it comes from a temporal shift due to the time needed for the movement of the arm to propagate towards the hand. In favor of this last hypothesis, the average duration of the variations of F0 is about 90 ms when the average duration of the gestures is about 150 ms. A gesture that begins from a proximal segment, cannot have fully developed over all the segments by the time the rise or fall of the fundamental frequency is reached. These questions explain a) the common structuration between prosody and gesture b) their synchronization c) the management of various temporalities.

Perspectives

The MODALISA project has reached its technological goal as we have now created a multimodal, multidevice platform in order to collect data on both speech and gesture as well as a methodology to process and analyze the multimodal data. The pilot study we presented in this paper indicates strong correlations between gestures and intonation when they are simultaneously performed by the speaker. The correlations are particularly strong for proximal segments. It would thus be particularly important to analyze head gestures (as advised by [START_REF] Bolinger | Intonation and gesture[END_REF]. The advantages of the MODALISA platform are that we use MOCAP systems with different frames of reference (absolute (EMA)/intrinsic (IMU) and that we have the possibility to integrate articulatory gestures (EMA), respiratory movements (respiratory belt), vibratory movements of the larynx (laryngograph) with prosody and gesture. We aim to adapt the IMU suit to children's physiological constraints. We can also coordinate the various exported data with our annotations of the video-data on ELAN. The platform is used in various projects by our team to study how prosody and gesture synchronize across the life-span in typical and atypical populations. Our goal is to capture whether integration of polysemiotic resources is quantitatively or qualitatively different in children as their motoric, cognitive and linguistic skills develop and in adults as they reach old age.

Figure 1 :

 1 Figure 1: Speaker (MO1) recorded with two different mocap systems: the electromagnetic articulograph (EMA, on the left) and the IMU suit (in the middle) with the visualization of the latter in Axis Neuron (on the right).

Figure 2 :

 2 Figure 2: Segmentation grid of a statement produced by the speaker MO1, with six tiers (Phonemes, Syllables, Words, Prominences, F0, Disfluencies) provided by the Praat software.

Speech rate Pitch range Mean Pitch Max pitch Speech time Phonation time

  Table1summarizes our main results for pitch. The speaker has approximately the same speech rate in both tasks. He has a larger speech range and a lower mean pitch with the IMU suit.

	Mocap							Pause time
	EMA	9,09	8,1 ½ tons	154 Hz	196 Hz	110,84 sec. 8,91 sec.	101,93 sec.
		syll/sec.					(8,04 %)	(91,96%)
	Noitom Suit	9,2 (6,23)	9,2 ½ tons	129 Hz	169 Hz	71,85 sec.	55,52 sec.	16,33 sec.
		syll/sec.					(77,28%)	(22,72 %)

Table 2 :

 2 Percentages of the number of correlation coefficients per range of 0.2 between rising fundamental frequencies and each degree of freedom of the right upper limb. The set of gestural possibilities are defined by degrees of freedom from shoulders to hands included 2 .

		Add/Abd Shoulder & F0⬊	Rot Ext/Int Arm & F0⬊	Exten/Flex Arm & F0⬊	Add/Abd Arm 1 F0⬊	Supi/Pro Forearm & F0⬊	Exten/Flex Forearm & F0⬊	Add/Abd Hand & F0⬊	Exten/Flex Hand & F0⬊
	% corr. coef. 1> x >0,8 or -0,8> x >-1	50,45%	78,18%	72,97%	73,87%	69,37%	75,68%	60,36% 70,27%
	% corr. coef. 0,8> x >0,6 or -0,6> x >-0,8	18,02%	12,73%	13,51%	14,41%	16,22%	14,86%	19,82% 15,32%
	% corr. coef. 0,6> x >0,4 or -0,4> x >-0,6	16,22%	5,45%	5,41%	6,31%	4,50%	3,60%	6,31%	6,31%
	% corr. coef. 0,4> x >0,2 or -0,2> x >-0,4	11,71%	1,82%	5,41%	4,50%	6,31%	3,15%	6,31%	4,50%
	% corr. coef. 0,2> x >-0,2	3,60%	1,82%	2,70%	0,90%	3,60%	2,70%	7,21%	3,60%

F0 ⬊

Table 3 :

 3 Percentages of the number of correlation coefficients per 0.2 range between descending fundamental frequencies and each degree of freedom of the right upper limb 3 .

Project funded by a grant awarded by the CNRS as part of the "Challenge Instrumentation aux Limites" call for projects in

(Coordination: Christelle Dodane).

The set of degrees of freedom are defined in the position of the Vitruvian man (man standing with his palms facing forward, circumscribed in a circle, illustrated by Leonardo da Vinci). Abduction / adduction is a degree of freedom that moves a segment or a shoulder away or closer to the bust, in a frontal plane. The extension / flexion makes the segment pass behind or in front of the frontal plane, still in this general reference position of the Vitruvian body. The outer / inner rotation and the supination / pronation are degrees of freedom that turn the segment on itself, arm for the first, forearm for the second.

The negative values of the correlation coefficients appear when for the same F0 slope, the pole of the correlated degree of freedom is of an opposite sign. Thus, when the correlation coefficient is negative, for a descending F0, then for example for the arm, its movement corresponds to a flexion (forward or upward). For a positive value, always with descending F0, the arm will have an extension movement (backward or downward).

Acknowledgments: The authors would like to thank Marjorie Bosqué and Cwiosna Roques for their annotation work on the data files.