Keywords: Advanced transactional models, Composite services, Reliability, Web services, Web service compositions, Workflow patterns

Web services are defined independently of any execution context. Due to their inherent autonomy and heterogeneity, it is difficult to examine the behaviour of composite services, especially in case of failures. This paper is interested in ensuring composite services reliability. Reliable composition is defined as a composition where all instance executions are correct from a transactional and business point of view. In this paper, the authors propose a transactional approach for ensuring reliable Web service compositions. The approach integrates the expressivity power of workflow models and the reliability of Advanced Transactional Models (ATM). This method offers flexibility for designers to specify their requirements in terms of control structure, using workflow patterns, and execution correctness. Contrary to ATM, the authors start from the designers’ specifications to define the appropriate transactional mechanisms that ensure correct executions according to their requirements.

Keywords: Model checking, Deadlock-freeness, Business process composition, Binary decision diagrams, WF-nets

The design of complex inter-enterprise business processes (IEBP) is generally performed in a modular way. Each process is designed separately and then the whole IEBP is obtained by omposition. Even if such a modular approach is intuitive and facilitates the design problem, it poses the problem that correct behavior of each business process of the IEBP taken alone does not guarantee a correct behavior of the composed IEBP (i.e.\ properties are not preserved by composition). Proving correctness of the (unknown) composed process is strongly related to the model checking problem of a system model. Among others, the symbolic observation graph based approach has proven to be very helpful for efficient model checking in general. Since it is heavily based on abstraction techniques and thus hides detailed information about system components that are not relevant for the correctness decision, it is promising to transfer this concept to the problem rised in this paper: How can the symbolic observation graph technique be adapted and employed for process composition? Answering this question is the aim of this paper.

Keywords: P2P, Learning routing methods and Clustering

Peer-to-peer systems have recently a remarkable success in the social, academic, and commercial communities. A fundamental problem in Peer-to-Peer systems is how to efficiently locate appropriate peers to answer a specific query (Query Routing Problem). A lot of approaches have been carried out to enhance search result quality as well as to reduce network overhead. Recently, researches focus on methods based on query-oriented routing indices. These methods utilize the historical information of past queries and query hits to build a local knowledge base per peer, which represents the user's interests or profile. When a peer forwards a given query, it evaluates the query against its local knowledge base in order to select a set of relevant peers to whom the query will be routed. Usually, an insufficient number of relevant peers is selected from the current peer's local knowledge base thus a broadcast search is investigated which badly affects the approach efficiency. To tackle this problem, we introduce a novel method that clusters peers having similar interests. It exploits not only the current peer's knowledge base but also that of the others in the cluster to extract relevant peers. We implemented the proposed approach, and tested (i) its retrieval effectiveness in terms of recall and precision, (ii) its search cost in terms of messages traffic and visited peers number. Experimental results show that our approach improves the recall and precision metrics while reducing dramatically messages traffic.

Keywords: Adaptability assessment, Mediated service interaction, Service protocol

Given the inherent autonomy, heterogeneity, and continuous evolution of Web services, mismatches usually exist between service protocols. Adapters are typically used to reconcile these mismatches. Before synthesizing an adapter, a service requestor is often willing to assess whether her expected interactions can be conducted or not. The effort of synthesizing an adapter is beneficial only if the result of this assessment is positive. Previous effort analyzing service interactions focused on either (i) compatibility analysis for checking whether interactions can be conducted in a direct manner or (ii) adapter synthesization for reconciling mismatches. In this paper we propose a new kind of adaptability assessment that (i) determines whether two service protocols of a requestor and a provider are adaptable, (ii) computes an adaptation degree, and (iii) identifies conditions that determine when these two service protocols can be adapted. This adaptability assessment provides complementary criteria to the service requestor for selecting a suitable service protocol from a set of functionally equivalent candidates according to her requirements.

Keywords: Business process modeling, Web service composition, Workflow pattern, Context matching, Recommender system

The WS-BPEL provides a standard for business processes abstraction and execution, in which, the business processes abstraction is the key step for the completeness and success of business processes. The business processes abstraction includes the behavior and interactions between services which are sketched out by business processes designers. The current business process design is labor-intensive and time consuming, especially when it is required to be detailed to ensure the success of the business execution. In this paper, we propose an approach that helps the business process designers facilitate the design step by providing them a list of related services to the current designed model. We propose to capture the requested service’s composition context specified through the process fragment surrounding it and recommend the services whose composition context in existing designed service compositions best match the given fragment context. Provided experimental evaluations in this paper show that our approach is efficient in realistic situations.

Keywords: Web service, Recommender system, Vector space model, Latent semantic indexing

The tremendous growth in the amount of available web services (WS) impulses many researchers on proposing recommender systems to help users discover services. Most of the proposed solutions analyzed query strings and web service descriptions to generate recommendations. However, text based recommendations approaches depend mainly on user's perspective, languages and notations which easily decrease recommendation's efficiency. In this paper, we propose to take into account user's behaviors instead of text based analysis. We apply collaborative filtering technique on user's interactions. We propose and implement two algorithms based on Vector Space Model and Latent Semantic Indexing to validate our approach. We also provide evaluation methods with different datasets in order to compare and assert the efficiency of our two algorithms.

Keywords: Communities of registries, Organization of web services registries, Service oriented computing

In this paper, we propose to use communities as a mean to organize Web services registries in a multi-registry environment. First, we propose a semantic model for Web services registry description (WSRD). A WSRD description depicts the functionalities offered by services advertised by a given registry. Thereafter, we propose an implicit approach for building communities based on the WSRD descriptions using a fuzzy clustering technique. Eventually, this clustering will be helpful for selecting an adequate registry for service requesters. Provided experiments in this paper show the feasibility of our approach.

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Service Component Architecture (SCA) aims to simplify the construction of service oriented architecture (SOA) to encourage better the reuse and to be independent from used technologies. In the other hand, UML is a standard for modeling especially in industrial environments. To face this situation we recommend an adaptation of UML2.0 to SCA. It is in this context that we have defined a profile UML2.0 for SCA contain a set of stereotypes applied to metaclasses stemming from the metamodel UML2.0. These stereotypes are completed by formal constraints in OCL. Our profile introduces new elements to reflect the architectural concepts of SCA.

Keywords: Web service registry, Registry community, Communities management

Web services discovery represents a prominent step in the development process of B2B applications. In such environment, the number of Web services as well as registries that are made available for use can be as many as the large number of companies. Thus, the Web services discovery process will be time consuming. To deal with this issue, one obvious solution is to group Web service registries into communities. However, this solution can raise a managing issue since registries and communities are dynamic by nature. Our major contribution in this paper is an approach for managing registries and communities to reconcile conflicts result of the dynamic change aspect of Web service registries.

Keywords: Multi-agent systems, Pervasive applications, Recommendation, User profile

In this paper we describe an agent-based system for user profiles dynamic share. We address the problem of discovery and construction of distributed user profiles for adapted services recommendation in the context of pervasive applications. The system has to be open and proactive in order to dynamically propose adapted services according to user's situation and contextual profile, while preserving his/her privacy. The objective of this work is to propose an infrastructure for developing pervasive learning environments to dynamically build the most suitable learner profile for a particular service or interaction in real-time. The implemented prototype is also presented, showing in detail how agents communicate.

Keywords: Learning object, Author assistance , Content indicators, Semantic metadata

Usually semantic metadata are introduced to support effective search of relevant learning objects from LOR (Learning Object Repositories). We propose to use them to assist authors of SCORM (Sharable Content Object Reference Model) like learning objects. In fact, when we design new learning objects by reuse of existing ones, there are risks to have weaknesses mainly due to a bad understanding of the true nature of the reused objects. To overcome those risks we have defined an automated authoring assistance approach. In this paper we focus especially on how we use semantic metadata to produce indicators about the content of learning objects, more precisely about their complexity, heterogeneity and imbalance from a semantic perspective. To attend this specific objective we introduce the notion of "semantic space" and "semantic component". Then we use them to compute metrics which are aggregated together to produce meaningful indicators.

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Although there are several approaches for adaptive e-learning systems, they focus mainly on technological and/or networking aspects without taking into account other contextual aspects, such as cultural and pedagogical context. This paper presents a context-aware situation-dependent personalization approach designed for an adaptive e-learning system called AdaptWeb®, based on a rich context model as an extension to student modeling.

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This paper described a new approach to user modeling in adaptive e-learning systems, taking into account contextual aspects to improve personalization capabilities. The main features of our approach are explained and illustrated and we detail each contextual dimension such as personal, educational, technological and specially cultural context. We present some examples from AdaptWeb® and show how context and culture could be modeled for personalization, making use of a set of ontologies for representing explicitly this rich context as an extension of traditional student modeling.

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Folksonomy systems and social bookmarking tools are rapidly spreading on the Web. Their steady increase reveals a trend towards a more dynamic and interactive space, in which users can individually assign terms to online resources. Even though users find tagging easy to use and understand, they need to see, closely, users sharing same interest as them for many reasons (facilitating the information retrieval and confidentiality management, insuring privacy respect, etc.). In this paper, we introduce a new method for automatically creating a new social network, across a popular folksonomy site, where users are clustered according to their domain of interest. We semantically represent these interests by using DBPEDIA ontology as a multi-domain ontology and we propose a methodology for enriching this ontology.

Keywords: Web service composition, Event-B, Transactional web service, Proof, Refinement, Verification

A key challenge of Web Service (WS) composition is how to ensure reliable execution. Due to their inherent autonomy and heterogeneity, it is difficult to reason about the behavior of service compositions especially in case of failures. Therefore, there is a growing interest for verification techniques which help to prevent service composition execution failures. In this paper, we present a proof and refinement based approach for the formal representation, verification and validation of Web Services transactional compositions using the Event-B method.

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The increasing use of Workflow Management Systems (WfMS) in companies expresses their undeniable importance to improve the efficiency of their processes and their execution costs. However, with the technological improvements and the continuous increasing market pressures and requirements, collaborative information systems are becoming more and more complex, involving numerous interacting business objects. Consequently, in spite of their obvious potential, WfMS show some limitations to ensure a correct and reliable execution. Therefore, there is a growing interest for verification techniques which help to provide reliable transactional workflow behavior and thereafter prevent workflow execution failures. In this paper, we propose a Petri net driven approach to validate workflow transactional behavior to subsequently improve and correct related recovery mechanisms. The transactional behavior verification is done at design time to validate the transactional behavior consistency and help designers to provide correct recovery mechanisms. By using Petri nets and Temporal Logic formalisms to specify and check the transactional behavior consistency, the approach we present in this paper provides a logical foundation to ensure workflow execution reliability.

Keywords: Cloud computing, Service container, Scalability

Cloud computing describes a new supplement, consumption, and delivery model for IT services based on Internet protocols, and it typically involves provisioning of dynamically scalable and often virtualized resources. In this paper, we propose to design and implement a new service micro-container to address scalability by reducing memory consumption and response time. We propose to dedicate a services micro-container for each deployed service and thus avoid the processing limits of classical services containers. Our micro-container is evaluated and compared to conventional Web containers to highlight our contribution.

Keywords: Ubiquitous learning, Project based learning, Collaborative learning, Lifelong learning

Mobile technologies are more and more present in students’ lives. It is therefore interesting to see how these technologies enable students to learn beyond their courses. In this paper, we describe an ongoing work funded by our institution. We are developing a prototype of a project-based learning ubiquitous platform which aims at helping students learn some skills and knowledge about project management. In accordance with project-based learning theories, our platform also teaches students how to collect knowledge and introduce them to lifelong learning technologies. The software is designed to be reused and adapted to various situations of ubiquitous and collaborative learning, for universal clients.

Keywords: Cluster network, Clustering , Data-providing services

In service-oriented computing, a user usually needs to locate a desired service for (i) fulfilling her requirements, or (ii) replacing a service, which disappears or is unavailable for some reasons, to perform an interaction. With the increasing number of services available within an enterprise and over the internet, locating a service online may not be appropriate from the performance perspective, especially in large internet-based service repositories. Instead, services usually need to be clustered offline according to their similarity. Thereafter, services in one or several clusters are necessary to be examined online during dynamic service discovery. In this paper we propose to cluster data providing (DP) services using a refined fuzzy C-means algorithm. We consider the composite relation between DP service elements (i.e., input, output, and semantic relation between them) when representing DP services in terms of vectors. A DP service vector is assigned to one or multiple clusters with certain degrees. When grouping similar services into one cluster, while partitioning different services into different clusters, the capability of service search engine is improved significantly.

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In this paper we propose a technique called replaceability assessment where, according to the adaptation mechanisms of a certain adapter, it provides a set of condition pairs that determine when one protocol can be replaced by another, and computes a replacement degree that specifies how replaceable two protocols are. The set of condition pairs and the replacement degree are complementary criteria to be used by the requestor for identifying the most suitable provider service from a set of functionally equivalent candidates.

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In this chapter, we present an approach for recommendation of learning materials to students in an e-learning environment. Our aim is to increase the current system's personalization capabilities for students in different scenarios making use of recommendation techniques. The recommendation is produced considering learning materials' properties, student's profile and the context of use. In addition, the process of recommendation is improved through students' collaboration. In the context of this work, a learning material is a link to a Web page or a paper available on the Web and previously stored in a private repository. The process of collaboration occurs during student's evaluations of the recommendations. These student's evaluations are used by the system to produce new recommendations for other students. The main features of the recommendations aspects are described and some examples are also used to discuss and illustrate how to provide this personalization.

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On trouve aujourd’hui les bases de données dans de multiples applications manipulant des volumes de plus en plus importants stockés sur un nombre de sites important. Ces données ont une structure généralement complexe intégrant souvent en plus une dimension temporelle et/ou spatiale, ce qui nécessite des mécanismes d’interrogation (basés sur l’agrégation notamment) et de mise à jour sophistiqués. Les articles contenus dans ce numéro couvrent principalement la gestion de données multidimensionnelles et la répartition à grande échelle. Ils ont été sélectionnés à partir d’articles présentés lors des 24e journées Bases de Données Avancées (BDA 2008) qui se sont déroulées à Guilherand- Granges (Ardèche) du 21 au 24 octobre 2008. BDA est la principale manifestation scientifique française pour les chercheurs qui travaillent sur la conception et le développement d’outils pour la gestion de données. Le premier article de Yoann Pitarch, Anne Laurent, Marc Plantevit et Pascal Poncelet traite de l’adaptation des techniques OLAP au contexte des flots de données. Pour ce faire, ils proposent une architecture compacte et qui permet une analyse multidimensionnelle et multiniveau. L’idée consiste à stocker non pas les données brutes trop nombreuses et peu intéressantes pour l’analyse, mais les données agrégées en fonction d’une part, des niveaux de granularité intéressants pour l’analyste et, d’autre part, de l’historique. Pour ce faire le modèle de fenêtre temporelle est utilisé qui permet de stocker les données les plus récentes avec un maximum de précision et d’oublier les plus anciennes. Nouha Bouteldja, Valérie Gouet-Brunet et Michel Scholl abordent l’accélération de la recherche par similarité dans les espaces à grande dimension où, à cause de la malédiction de la dimension, les index multidimensionnels classiques ne fonctionnent pas. Cet article propose un nouveau modèle basé sur une hiérarchie d’espaces, HiPeR, qui est indépendant des données et des index utilisés. HiPeR a été adapté pour une recherche approximative où la précision est contrôlée grâce à un modèle probabiliste. Des stratégies de recherche efficaces pour les requêtes multiples sont également présentées. Khaled Jouini et Geneviève Jomier s’intéressent à optimiser l’accès en lecture à des données temporelles en se focalisant sur la hiérarchie de caches entre disque et mémoire vive. Ils montrent que le modèle classique de stockage des données dans une page supporté par les SGBD n’est pas adapté aux données temporelles et ils en proposent deux autres TDSM et PSP basés sur une organisation en colonnes. Idrissa Sarr, Hubert Naacke et Stéphane Gançarski proposent une infrastructure distribuée à large échelle sur une grille pour supporter l’exécution d’applications bases de données à fort taux de mises à jour. Ce problème devient très important aujourd’hui dans le cadre du cloud computing. Les données applicatives sont répliquées sur un ensemble de sites sur la grille avec des niveaux de fraicheur différents (certaines répliques sont à jour, d’autres n’ont pas encore effectuées les dernières mises à jour). A chaque exécution d’une application, un routeur doit choisir la réplique qui assurera un bon niveau de performance tout en respectant le critère de fraicheur défini par aux fautes et qui s’appuie sur un annuaire stocké dans une mémoire virtuelle répartie. Le dernier article de Hicham Idabal et Françoise Gire revient sur un problème classique en gestion de données, à savoir la mise à jour à travers les vues, mais appliquée ici aux données non structurées. Le problème général est de pouvoir décider si une vue définie par une requête arbre est modifiée par une classe de mises à jour définie par une autre requête arbre spécifiant les noeuds à modifier (mais sans spécifier la nature de la modification). Une variante également étudiée suppose la connaissance d’un schéma pour les documents sources. L’originalité ici repose sur le fait que l’on n’utilise pas les documents sources mais seulement la requête les définissant (plus éventuellement un schéma). Les auteurs ont pu établir une condition suffisante en temps polynomial sur les entrées pour le cas avec schéma ainsi que plusieurs caractérisations en complexité pour les autres cas. Je tiens à remercier tous les auteurs pour leur excellente contribution, Jean-Marc Petit et toute son équipe pour leur parfaite organisation des journées, David Gross-Amblard et le comité de sélection des démonstrations et enfin tous les membres du comité de programme de BDA 2008 qui ont participé à l’évaluation des articles sélectionnés pour ce numéro.

Keywords: Monitoring, Reliability, Verification, Transactional Web services, Web services compositions

Different from process components, Web services are defined independently from any execution context. A key challenge of (Web) service compositions is how to ensure reliable execution. Due to their inherent autonomy and heterogeneity, it is difficult to reason about the behavior of service compositions especially in case of failures. Therefore, there is a growing interest for verification techniques which help to prevent service composition execution failures. In this paper, we propose an event-driven approach to validate the transactional behavior of service compositions. The transactional behavior verification is done either at design time to validate recovery mechanisms consistency, or after runtime to report execution deviations and repair design errors, and therefore, formally ensure service execution reliability. By using the Event Calculus formalism to specify and check the transactional behavior consistency of service composition, our approach provides a logical foundation to ensure service execution reliability.

Keywords: Intelligence dans les procédés métiers, Patrons de workflow, Fouille de workflow

La fouille de workflow rassemble des techniques de (re)conception rétroactive nécessaires à la compréhension de la réalité de l’exécution des procédés métiers. Notre approche décrit une analyse statistique des événements de traces d’exécution pour la découverte des patrons de workflow. Elle est caractérisée par une découverte « locale » de patrons de workflow. Ces derniers découverts, seront, par la suite, itérativement composés jusqu’à la construction finale du modèle entier du workflow. L’analyse des disparités entre les modèles découverts et initialement conçus nous permet de détecter des lacunes concernant la conception initiale qui peuvent être exploitées dans un processus de réingénierie. Notre approche a été validée dans un prototype WorkflowMiner et un plug-in dans la plateforme ProM.


Workflow mining refers to retroactive (re)design techniques necessary to understand business process execution reality. Our workflow mining approach describes a statistical technique to discover workflow patterns from event-based log. It is characterised by a "local" workflow patterns discovery that allows to cover partial results. The discovered workflow patterns are then composed iteratively until discovering the global workflow model. The analysis of the disparities between the discovered model and the initially designed model enables us to be detect initial design gaps that can used in reengineering process. Our approach has been implemented within our prototype WorkflowMiner and a ProM framework plug-in.

Keywords: Capacity, Composition, Requirement, Web service

This paper presents the concepts, definitions, issues, and solutions that revolve around the adoption of capacity-driven Web services. Because of the intrinsic characteristics of these Web services compared to regular (i.e., mono-capacity) Web services, they are examined in a different way and across four steps denoted by description, discovery, composition, and enactment. Implemented as operations to execute at run-time, the capacities that empower a Web service are selected with respect to requirements put on this Web service such as data quality and network bandwidth, and hence need to be satisfied through these capacities. In addition, this paper reports on first, the experiments that were conducted to demonstrate the feasibility of capacity-driven Web services and second, the research opportunities that will be pursued in the future.

Keywords: Data aggregation, Spatio-temporal data, Sensor data, Event streams, Vehicular ad hoc networks (VANET)

This article focuses on data aggregation in vehicular ad hoc networks. In such networks, sensor data are usually produced and exchanged between vehicles in order to warn or inform the drivers when an event is detected (e.g., accident, emergency braking, parking space released, vehicle with non-functioning brake lights, etc.). In the following, we present a solution to aggregate and store these data in order to have a history of past events. We therefore use Flajolet-Martin sketches. Our goal is to generate additional knowledge to assist drivers by providing them useful information even if no event is transmitted by vehicles in the vicinity.


Dans cet article, nous nous intéressons à l'agrégation de données dans les réseaux ad hoc inter-véhicules. Dans ces réseaux, des données sont produites par des capteurs et échangées entre véhicules pour informer ou avertir les conducteurs lorsqu'un événement survient (e.g., accident, freinage d'urgence, place de stationnement libérée, un véhicule avec les feux stop défectueux, etc.). Dans la suite, nous proposons d'agréger et de stocker ces données afin de conserver un historique des événements précédemment observés. Nous utilisons pour ce faire des sketches Flajolet-Martin. Notre objectif est ici de générer des connaissances additionnelles afin d'assister les conducteurs en leur proposant des informations pertinentes, y compris lorsqu'aucun événement n'est communiqué par les véhicules à proximité.

Keywords: Web service, Recommender system, Vector space model

The tremendous growth in the amount of available web services impulses many researches on proposing recommender systems to help users discover services. Most of the proposed solutions analyzed query strings and web service descriptions to generate recommendations. However, these text based recommendations approaches depend mainly on user's perspective, languages and notations which easily decrease recommendation's efficiency. In this paper, we present our approach in which we take into account historical usage data instead of the text based analysis. We apply collaborative filtering technique on user's interactions. We propose and implement three algorithms based on Vector Space Model to validate our approach. We also provide evaluation methods based on the precision, recall and root mean square error in order to compare and assert the efficiency of our algorithms.

Keywords: Web service discovery, Web service recommandation

The tremendous growth in the amount of available web services (WS) impulses many researchers on proposing recommender systems to help users discover services. Most of the proposed solutions analyzed query strings and web service descriptions to generate recommendations. However, text based recommendations approaches depend mainly on user's perspective, languages and notations which easily decrease recommendation's efficiency. Moreover, new published web services often have lower priorities to be selected for recommendations.\\In this paper, we propose to take into account user's behaviors instead of text based analysis. We apply collaborative filtering technique on user's interactions. We propose and implement three algorithms (user-based, operation-based and priority-based) to validate our approach. We also provide evaluation methods which indicate that our approach produces high quality recommendations in case users have stable behavior.

Keywords: Web service discovery, Recommender system, P2P

The discovery of suitable Web services for a given task is one of the central operations in Service-Oriented Architectures, and research on Web services (WS)s aims at automating this step. For the large amount of available WSs that can be expected in real-world settings, the efficiency of automated discovery becomes important. For this, we propose to exploit previous discovery results to reduce the search space in distributed registry environment. The architecture we adopt consists in structuring registries of WSs into communities. Then, we propose to adapt recommendation techniques to ease the services discovery process. This consists of (1) the selection of communities of registries using semantic matching and (2) the recommendation of registries within these communities using user-characterization based technique. To put our proposed distributed registry architecture in practise and to test the efficiency of recommendation-based discovery, we propose to implement a Peer-to Peer (P2P) registries environment on top of JXTA platform.

Keywords: Web Service, Web service description, Web Service Registries, Clustering

Web service registries play an important role in service oriented applications. They constitute the market where service consumers and providers go to search and advertise Web services. With the proliferation of Web service registries, finding an adequate registry has become a complex task for a service requester. In this paper we propose a semantic model for Web services registry description (WSRD). WSRD descriptions depict the functionalities offered by services advertised by a given registry since they rely on these descriptions. We also propose a functionality-driven clustering approach for distributed Web service registries. This approach is based on a fuzzy clustering technique and allows structuring distributed registries based on their WSRD descriptions without any additional data. This clustering will be helpful for selecting an adequate registry for service requesters.

Keywords: Web services, Capacity-driven Web services, Service modelling

This paper presents a novel approach for the engineering of capacity-driven Web services. By capacity, we mean how a Web service is empowered with several sets of operations from which it selectively triggers a set of operations with respect to some run-time environmental requirements. Because of the specificities of capacity-driven Web services compared to regular (i.e., mono-capacity) Web services, their engineering in terms of design, development, and deployment needs to be conducted in a complete specific way. Our approach define an engineering process composed of five steps: (1) to frame the requirements that could be put on these Web services, (2) to define capacities and how these capacities are triggered, and last but not least link these capacities to requirements, (3) to identify the processes in term of business logic that these Web services could implement, (4) to generate the source code, and (5) to generate the Capacity-driven Web Services Description Language (C-WSDL).

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One issue for context-aware applications is to identify without delay situations requiring reactions. The identification of these situations is computed from both dynamic context information and domain specific knowledge. This identification is the output of a process involving context interpretation, aggregation and deduction. In smart environments, these treatments have to be efficient since they may be partly performed on constrained mobile devices. Two main approaches exist in the literature: process-oriented and ontology-based context management. In this paper, we claim that they are complementary and we propose an architecture which integrates the two approaches. We show in a scenario how context-aware applications can benefit from this architecture both to scale to numerous mobile users and to identify complex situations.

Keywords: Personal learning environment , Contextual learning experience sharing, Trusted social network, Lifelong learning, Peer-to-peer sharing

This paper addresses questions of contextual learning experience sharing among users in personal learning environments. As learning environments has become personal and user oriented, a user can acquire knowledge and learning experiences anywhere and anytime by reading public or personal online learning resources aggregated by a set of provided tools. In this paper, we propose a system allowing a user to share his contextual learning experiences with his/her friends by sharing his contextual learning histories. This experience is propagated to others by using a trusted social network. Our system not only helps users to spread their learning experiences but also ensures user privacy (individual knowledge and preferences). It can be applied to enhance lifelong learning.

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The main topic of this paper is to propose two complementary learning strategies: situation-based and activity-based to fulfill seamless learning across contexts and worked-based learning requirements. In situation-based learning, relevant resources are recommended to the user depending on the current situation. In activity-based learning, the user has to search and to select his/her activities and the corresponding resources. These strategies correspond to two different information dissemination approaches that can be distinguished, namely push and pull (Cheverst, Mitchell, & Davies, 1998). We propose a pervasive learning environment where learners may follow different learning strategies. They may switch from one strategy to the other one according to their needs and/or the context changes. These facilities are possible thanks to a set of models and adaptation processes developed for the P-LearNet project (Pervasive Learning Network). To illustrate this proposal, a use case from this project is used.

Keywords: Web service discovery, Web service matching

In this paper, we present new algorithms for matching Web services described in YASA4WSDL (YASA for short). We have already defined YASA, a semantic description of services that overcomes some issues in WSDL or SAWSDL. In this paper, we continue on our contribution and show how YASA Web services are matched based on the specificities of YASA descriptions. Our matching algorithm onsists of three variants based on three different semantic matching degree aggregations. This algorithm was implemented in YASA-M, a new Web service matchmaker. YASA-M is evaluated and compared to well known approaches for service matching. Experiments show that YASA-M provides better results, in terms of precision, response time, and scalability, than a well known matchmaker.

Keywords: WSDL, Web service, Service discovery

In this paper, we present new algorithms for matching Web services described in YASA4WSDL (YASA for short). We have already defined YASA that overcomes some issues missing in WSDL or SAWSDL. In this paper, we continue on our contribution and show how YASA Web services are matched based on the specificities of YASA descriptions. Our matching algorithm consists of three variants based on three different semantic matching degree aggregations. This algorithm was implemented in YASA-M, a new Web service matchmaker. YASA-M is evaluated and compared to well known approaches for service matching. Experiments show that YASA-M provides better results, in terms of precision, response time, and scalability, than a well known match-maker.

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Keywords: Adaptation, Context-aware, Learning environments, Cultural-aware

Since e-learning systems are used by a wide variety of students with different characteristics, being adapted to user’s model and profile is an essential feature. Although there are several approaches for adaptive e-learning environments, they focus mainly on technological and/or networking aspects without taking into account other contextual aspects, such as cultural and pedagogical context. This paper presents an improvement of an adaptive elearning environment called AdaptWeb®, based on a rich context model as an extension to the traditional student modeling.

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Nowadays e-learning systems (ELSs) are used by a wide variety of students with different characteristics. Thus, adapting it to specific users, taking advantage of knowledge acquired and registered about them (the user's model, which in ELS domain is usually called student model) is an essential feature in order to improve usability and flexibility of ELSs. In fact, the use of personalization techniques aims at improving ELS usability since a personalized system automatically customizes the user interface, content, access rights, navigation, etc., considering the student model and each user may think that the system was designed specifically for him/her. This paper presents the context-aware and culture-oriented aspects of an adaptability approach designed for ELS. The main features of our approach are described and illustrated, showing how to use it to model context and culture for personalization of ELS, representing explicitly the rich context as an extension of traditional student modeling and making use of ontologies to model it.

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Keywords: Web services, Recommender system, Research roadmap

In this position paper we provide a brief overview of Recommender Systems (RS) and Web Services (WS). After, we propose a research roadmap for the challenges and opportunities that could arise following the combined use of WS and RS. While these challenges are expected to hinder this use, we discuss the neces-sary actions that need to be taken to overcome these challenges and hence, make this use a win-win situa-tion for both WS and RS. We illustrate how the combination of RS to WS takes place in terms of what RS can do for WS and what WS can do for RS. Finally, we conclude by pointing out the actions to take so that this combination turns out successful.

Keywords: Inter-organizational, Workflows, Time modeling, Deadline constraints, Time petri net

The integration of time constraints in Inter-Organizational Workflows (IOWs) is an important issue in the workflow research field. Since each partner exposes a limited version of his business process, some information is kept hidden and not visible to all partners. The inter-enterprise business process, however, is obtained by joining all activities and control flows that have relevant roles within the context of the global operation. It should be noted that this composition process does not intrinsically guarantee the satisfaction of any critical deadline constraints that may be imposed by the partners. Obviously, expressing and satisfying time deadlines is important for modern business processes that need to be optimized for efficiency and extreme competitiveness. In this paper, we propose a temporal extension to CoopFlow, an existing approach for designing and modeling IOW, based on Time Petri Net models. A method for expressing and publishing sensible time deadlines, by the partners, is given. We also give a systematic method assuring the verification and the consistency of the published time constraints within the context of the global business process, while maintaining the core advantage of CoopFlow, that each partner can keep the critical part of his business process private.

Keywords: Inter-organizational workflows, Modelling time constraints, Petri nets

This paper deals with the integration of temporal constraints within the context of Inter-Organizational Workflows (IOWs). Obviously, expressing and satisfying time deadlines is important for modern business processes, and need to be optimized for efficiency and extreme competitiveness. In this paper, we propose a temporal extension to CoopFlow, an existing approach for designing and modeling IOWs, based on Time Petri Net models and tools. Methods are given, based on reachability analysis and model checking techniques, for verifying whether or not the added temporal requirements are satisfied, while maintaining the core advantage of CoopFlow; i.e. that each partner can keep the critical parts of its business process private.

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Keywords: P2P systems, Direct trust, Indirect trust, Trust paths, Trust values

The Peer-to-Peer systems (P2P) are a center of interest in the community of distributed systems, since their advantages in the adaptability and the robustness with regard to the traditional architectures client / server. Unfortunately, the anonymous and open nature of these systems involves an almost impossible surveillance of the network and offers nearly an ideal environment for the spread of the inauthentic files. To offer a more extensive vision of the network and to limit the malicious interactions between different peers of the network, we present a new model of trust management that considers the direct trust based on the peer’s history of uploads and the indirect trust which is calculated after constructing trust paths.

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AdaptWeb® is an e-learning environment designed to offer personalized content to different groups of students according to student's models that are mainly based on personal information. This paper shows how the platform is modified to support ubiquitous learning, managing mobility, social interaction, device independence, and context awareness in a broader and richer notion of the student's context. The paper presents the architecture and its implementation by three different kinds of data servers, working together for modeling the situations experienced by the students, storing their profiles and contexts, and maintaining corresponding learning objects.

Keywords: Context, Ontologies, Situations and scenarios, E-learning

This paper presents an architecture to transform an existent e-learning environment in a situation-aware environment, bringing the concepts of context awareness, situation and scenario to this environment. For a specific scenario, ontologies may be employed to represent the knowledge that the system has on the domain to be studied, on the situation where the study is being performed and also based in the student profile. In this sense, we present an alternative to transform the vision of situation-awareness in a daily reality, automatically defining the student situation and recommending adaptive actions.

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The amounts of digital information are growing in size and complexity. With the emergence of distributed services over internet and the booming of electronic exchanges, the need to identify information origins and its lifecycle history becomes essential. Essential because it’s the only factor ensuring information integrity and probative value. That’s why in different areas like government, commerce, medicine and science, tracking data origins is essential and can serve for informational, quality, forensics, regulatory compliance, rights protection and intellectual property purposes. Managing information provenance is a complex task and it has been extensively treated in databases, file system and scientific workflows. However, provenance in the cloud is a more challenging task due to specific problems related to the cloud added to the traditional ones.

Keywords: Apprentissage en ligne, Approche d'assistance aux auteurs

Cette thèse se situe dans le domaine de la création de contenus pédagogiques par une approche basée sur une structuration à base d’objets d’apprentissage et leur réutilisation au sein d’objets plus complexes. Les modèles récents d’objets pédagogiques comme SCORM ou SIMBAD permettent aux auteurs de construire de nouveaux objets par assemblage d’objets existants. La difficulté pour les auteurs est de concevoir de tels objets en maitrisant la complexité de la composition et en pouvant garantir un haut niveau de qualité, y compris pédagogique. Nous proposons dans ce travail une approche d’assistance aux auteurs basée sur un ensemble d’outils d’analyse permettant de mieux qualifier l’objet composé et d’en vérifier la conformité. Ces analyses portent tant sur le contenu de l’objet, ses métadonnées notamment celles issues de la norme LOM, que sur la structure de composition elle-même. L’objectif est de générer une cartographie détaillée sur l’objet en question. Il s’agit d’offrir à l’auteur des indicateurs divers et variés qui vont lui permettre d’avoir une meilleur vue sur les différentes facettes de l’objet d’apprentissage en cours de conception. En particulier, il aura une analyse de la vue système et de la vue apprenant. Une fois que l’analyse est satisfaisante, des métadonnées complémentaires sont calculées automatiquement par notre environnement en se basant sur les métadonnées éducatives des objets utilisés dans la composition de l’objet. La composition d’un objet peut être guidée par des règles de conformité. Celles-ci permettent de décrire certains critères structurels et sémantiques recherchés. Cette approche offre ainsi un moyen pour la promotion de la réutilisation des objets d’apprentissage. Elle offre le support théorique et les éléments pratiques permettent de rendre la composition par réutilisation pleinement sous contrôle de l’auteur et capable de produire par conséquence des objets d’apprentissage respectant des critères de qualité.


This thesis is situated in the e-learning domain and in the context of the authoring of educative content (composed learning objects) by reuse of learning objects. This approach is supported by many models like SCORM or SIMBAD. Using such as approach by authors still difficult due to the complexity of the composition process influencing the quality of the content especially from a pedagogical point of view. We propose in our research works an author assistance approach with a set of analysis tools which offer best understanding of the true nature of the composed learning object and its degree of conformity to the author, the model and the use context requirements. Analyses are applied to the learning object’s content, educative metadata and composition structure. The goal is to generate a learning object’s detailed cartography. Automatic generated indicators reveal details about the different facets of the composed learning object especially the system view and the learner view. If the analysis is satisfactory additional metadata are then automatically calculated by the tools based on the reused learning objects’ metadata. The learning object’s composition can be guided by some conformity rules. Those rules can cover intended structural and semantic criterion. Our approach offers a support to promote the reuse of learning objects in an effective manner. It provides theoretical and practical elements allowing authors to control the “authoring by reuse” process. Consequently our approach allows authors to produce high quality composed learning objects.

Keywords: Pair-à-pair, Recherche d'information, Indexation

Cette thèse se base sur une vision originale des systèmes de Recherche d'Information en pair-à-pair (RI-P2P) ; pour proposer un ensemble d'outils pour mieux les évaluer et mieux les concevoir.Synthétiquement, la problématique d'évaluation consiste à comprendre quel système fonctionne bien dans quelles conditions ; comment les différents composants/aspects d'un système contribuent à ses performances ; comment des modifications du système peuvent faire évoluer ses performances. D'un point de vue conception, on voudrait savoir choisir une approche P2P en fonction du contexte de l'application à implémenter (jeu de données, propriétés du réseau...) ; comprendre comment mixer des systèmes ; mieux maîtriser l'impact d'une modification de l'implémentation sur le comportement et les performances d'un système.Nous pensons que ces deux problématiques d'évaluation et de conception sont fortement liées. Un même fondement est nécessaire pour progresser dans ces deux sens : mieux comprendre l'architecture des systèmes RI-P2P. À la base de notre réflexion, nous considérons qu'un système RI-P2P est l'implémentation en P2P d'un modèle RI, idée qui s'oppose au modèle traditionnel en deux couches. Nous nous appuyons sur cette idée pour donner un ensemble de définitions qui permettent de mieux appréhender les différents composants RI et composants P2P d'un même système et la façon dont ils s'organisent. Nous montrons ensuite comment on peut utiliser cette vision originale du domaine pour spécifier la démarche d'évaluation d'un système P2P et pour aider à la conception de nouveaux systèmes.


This PhD thesis develops an original vision of Peer-to-Peer Information Retrieval Systems. Based on this vision, we ropose a set of tools for a better evaluation and conception of P2P-IR systems.Synthetically, on the one hand, evaluating means understanding which system behaves well in which context ; how different components/aspects of a single system contribute to its performance ; how modifications of the system can make its performance evolve. On the other hand, considering design of P2P-IR systems, we would like to be able to choose a P2P approach based on what is known about the context the application will execute in (data set, network properties...) ; understand how to mix P2P systems ; better control the impact of a modification of the implementation of a system on its behavior an performance.We believe those concerns of evaluation and design are strongly related. There is a common need to improve on both directions : better understand the architecture of P2P-IR systems. On the basis of our reflexion, we consider a P2P-IR system is the implementation in P2P of an IR system, which contrasts with the traditional two-layered vision. We use this idea to give a set of definitions that help better understand the different RI and P2P components of a single system and their relationships. We then show how this vision can be used to help design new systems.

Keywords: Registry description, Web service, Web services registry

Web services registries play an important role in service oriented applications. They constitute the market where services consumers go to search for a desired Web service. With the proliferation of Web services registries, finding an adequate registry has become a complex task for a service requester. In this paper we propose a semantic model to describe Web services registries (WSRD). WSRD descriptions are functionalitydriven since they rely on the registry’s Web services description. We also propose an approach for computing WSRD descriptions and mechanisms to handle their updates. Experimental evaluation shows that our approach is usable in realistic situations.

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Les systèmes d'information adaptatifs, sémantiques et pervasifs sont conçus pour être accessibles sur Internet, possèdent une architecture distribuée, accèdent à une masse de ressources hétérogènes qu'il s'agit de réutiliser, de partager, assurent une adaptation/personnalisation en fonction des besoins des utilisateurs et de leur contexte et permettent la coopération homme/machine et/ou entre individus appartenant à une même communauté de pratique à travers le web. Ces systèmes sont basés sur une boucle perception de l'environnement, découverte/sélection, décision, adaptation, déploiement. Cette problématique recouvre un large spectre d'applications. Les EIAH constituent un domaine d'application privilégié qui illustre une grande partie de cette problématique. En effet, les EIAH sont des environnements informatique conçus pour favoriser l'apprentissage humain, c'est-à-dire la construction ou le développement de connaissances chez un apprenant. Nous présentons ici nos principaux résultats qui s'articulent autour de trois axes : La composition adaptative de ressources; L'adaptation au contexte et son application à l'apprentissage pervasif; L'intégration sémantique de ressources hétérogènes.

Keywords: Workflow mining, Transactional workflow, Workflow patterns, Workflow logs, Process mining, Business process analysis, Business process intelligence, Process reengineering, Execution reliability, Correction

A continuous evolution of business process parameters, constraints and needs, hardly foreseeable initially, requires a continuous design from the business process management systems. In this article we are interested in developing a reactive design through process log analysis ensuring process re-engineering and execution reliability. We propose to analyse workflow logs to discover workflow transactional behaviour and to subsequently improve and correct related recovery mechanisms. Our approach starts by collecting workflow logs. Then, we build, by statistical analysis techniques, an intermediate representation specifying elementary dependencies between activities. These dependencies are refined to mine the transactional workflow model. The analysis of the discrepancies between the discovered model and the initially designed model enables us to detect design gaps, concerning particularly the recovery mechanisms. Thus, based on this mining step, we apply a set of rules on the initially designed workflow to improve workflow reliability.

Keywords: Community, JXTA, Web service, High availability , Replication strategy

In any critical system, high-availability of software components like Web services has so far been achieved through replication. Three replication strategies known as active, passive, and hybrid, describe for example how many replicas are needed, where to locate replicas, and how replicas interact with the original Web service and among themselves if needed. The purpose of this paper is to show how replicates could be substituted with components that are similarly functional to the component that needs back-up in case of failure.

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Service Oriented Computing (SOC) has gained maturity and there have been various specifications and frameworks for realization of SOC. One such specification is the Service Component Architecture (SCA), which defines applications as assembly of heterogeneous components. However, such assembly is defined once and remains static for fixed components throughout the application life-cycle. To address this problem, we have previously proposed an approach for dynamic selection of components in SCA, based on functional semantic matching and non-functional strategic matching using policy descriptions in SCA. In this paper, we extend our existing approach by providing further flexibility in component selection and present the architecture and implementation of our system. An evaluation of the system is also reported.

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Keywords: Web service, P2P, Recommender system, Web services discovery

In this paper, we discuss the suitability of using recommendation techniques for Web service discovery in distributed registry environments. The architecture we adopt consists in structuring registries of Web services into groups. We propose to adapt existing techniques for recommendation to ease the services discovery process. This consist of (1) recommendation of groups of registries using semantic matching and (2) recommendation of registries within these groups using user-characterization based technique. To put our proposed distributed registry architecture in practise and to test the efficiency of recommendation-based discovery, we propose to simulate a Peer-to-Peer (P2P) registries environment on top of JXTA platform.

Keywords: Learning object composition, Dynamic annotation, Visual search

This paper presents a complete visual environment which supports the search and composition of learning objects (LOs). It focuses on the end user, learner or teacher. Learners search for LOs in order to learn a new concept or to follow a lesson. Teachers search for LOs for direct use during their lessons or in order to reuse and assemble them with others, thus creating their own, novel LO. Nevertheless, the inner complexity of an LO makes searching for and reusing composed LOs a complex task as well. The end user has to be assisted during this task. The core of our environment is built with a navigational and iterative query language, and a composition model. An iterative, navigational, query language is a complex language. The end user cannot express search queries directly in such a textual language. In the same way, the teacher cannot use a complex textual language to compose a new LO. Our environment is a suite of visual interfaces, supporting interaction with the end user while hiding the inner complexity of the system. Last, a validation module validates the consistency of a composed LO and provides for the dynamic annotation of metadata.

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Current learning technology standards and recommendations have defined common languages for describing and sequencing learning resources. But further work is needed to support authors during their tasks (design, indexation, composition, search, insertion), which are essential to achieve a high level of automation. This paper proposes an author system to facilitate searching and dynamic composition of learning objects. This system allows an automatic generation of composed learning objects metadata and proposes some coherence validation

Keywords: Mobile applications, Recommender system, Situation, Awareness

Users in a campus need information about relevant individuals, buildings, events and available resources. In this paper, we propose a system to perform situation-aware adaptive recommendation of information to assist mobile users in a campus environment. The idea is to show information about the most relevant buildings and particular individuals situated nearby the user, taking into account the user situation, i.e., a snapshot of his/her context in a given instant, including his/her current activity, position and profile. This recommendation must be adapted, depending on the dynamic evolution of the user situation. Thus, the system is pervasive in the sense that it performs the most suitable recommendation at the right moment in the right place. A prototype of the recommender is being implemented.

Keywords: Semantic Web services, Web service description, Web service ontology

The lack of semantics in Web Services Description Language (WSDL) prevents automatic discovery and hence automatic invocation and composition. In our work, we are interested in extending existing approaches for the description of Semantic Web Services. Previously, we have extended the W3C recommendation on Semantics for Web Services (SAWSDL) and have proposed the use of two types of ontologies: a Technical Ontology type containing concepts defining semantics of services, their QoS... and a Domain Ontology type containing the concepts defining the semantics of the business domain. The aim of this paper is to present Yet Another Semantic Annotation for WSDL (YASA4WSDL) and define a technical service ontology for YASA4WSDL. This ontology integrates useful concepts of WSDL metamodel, and OWL-S and WSMO ontologies. The integration of these ontologies is based on different matching techniques according to an ontology mapping process. The resulting ontology covers specific Web services semantic concepts.

Keywords: XML, XQuery, Query by example

To search for specific elements in a marked up document we have, at least, two options: XPath and XQuery. However, the learning curve of these two dialects is high, requiring a considerable level of knowledge. In this context, the traditional Query-by-example methodology (for Relational Databases) can be an important contribute to make easier this learning process, freeing the user from knowing the specific query languages details or even the document structure. In this paper, we describe how we implement Query-by-example in a Web-application for information retrieval from a collection of structured documents, the GuessXQ system. In essence, we built an engine capable of deduce, from a specific example, the respective XQuery statement. After inferring the generic statement, the engine applies it to all documents in the collection to perform the desired retrieval. A suitable interface allows the end-user to mark over a sample document, picked up from the collection, the path he wants to select.

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Keywords: Workflow models, Choreography abstraction, Interface behaviour, Workflow integration

Workflow models have been used and refined for years to execute processes within organisations. To deal with collaborative processes (choreographies) these internal workflow models have to be aligned with the external behaviour advertised through Web service interfaces. However, traditional workflow management systems (WfMS) do not offer this functionality. Simply sharing and merging process models is often not possible, because workflow management lacks a widely accepted standard theory for workflow models.Multiple research and standardisation efforts to integrate different workflow theories have been proposed over the years. XPDL is the most widely used standard for process model interchange and supported by over 80 systems.However, XPDL also lacks the possibility to relate a workflow model to its possible choreography interface abstractions.To remedy this situation, we propose to abstract the XPDL model to a higher-level model, perform the integration and the compaction algorithms at that level and then ground it back to the desired choreography models. We develop and use an integrated ontology which is based on the XPDL standard for this purpose. To facilitate the abstraction and grounding, we present a mapping procedure to automatically translate XPDL and BPMN workflow models into this ontology. After translation, these models are annotated with a parameterised role model and other collaborative properties. We present a compaction procedure that automatically maps the annotated models into external choreography interfaces that expose only the relevant information for a particular partner collaboration. Our procedure is agnostic with respect to the target choreography model. We demonstrate our approach using WSMO choreographies which enables us to automatically generate interface models from any WfMSs that supports XPDL export.

Keywords: Business process, Workflow, Verification, Symbolic observation graphs

Web services can be viewed as processes of an enterprise which are used by (processes of) other enterprises. So, when offering a web service, it is necessary to publish sufficient information about the interface of the web service process. On the other hand, details of the internal behaviour of a web service should be hidden. So the design of complex inter-enterprise business processes(IEBP) employing web services is generally performed in a modular way. Each service is designed separately from the others and then the whole IEBP is obtained by composition. Even if such a modular approach is intuitive and facilitates the design problem, it poses the problem that correct behavior of each service of the IEBP taken alone does not guarantee a correct behavior of the composed IEBP (i.e. properties are not preserved by composition). In this paper, we address this problem. First, we propose to use a new variant of symbolic observation graphs as an abstraction of any service of the IEBP (only cooperative activities are visible). Local deadlock freeness can be checked efficiently on such an abstraction using symbolic algorithms. Second, we propose to synchronize the symbolic observation graphs associated with the different processes of the IEBP and supply an efficient algorithm for the verification of deadlock freeness of the synchronized product. The deadlock freeness of such a product guarantees a correct possible cooperation between the underlying processes (i.e. a deadlock free cooperation).

Keywords: P2P, Web services, Availability

This paper introduces an approach that aims at sustaining the high-availability of Web services using a similarity-based active replication strategy. Web service availability is defined as the proportion of time that this Web service remains functioning at a satisfactory level. Current high-availability approaches promote the use of techniques based on “exact” replicas to the original Web service that needs to be backed up when failures occur. Three replication strategies known as active, passive, and hybrid, are studied in this paper and permit to identify how many replicas are needed, how replicas interact with the original Web service, etc. Our approach takes replication one step further by focussing on Web services that offer the same functionality as the original Web service does (i.e., the one to back up). This functionality similarity is built upon the development of communities that gather similarly-functional Web services. Similarity-based replication offers solutions to some limitations of the existing replication strategies, but at the same time raises other issues that need to be tackled in the particular context of communities. To prove the suitability of the active replication strategy for Web services high-availability, a P2P testbed on top of the JXTA platform is developed.

Keywords: Web service description, Web service discovery

This paper is an overview of how capacity-driven Web services are defined and put into action. Because of the specificities of these Web services compared to regular (i.e., mono-capacity) Web services, the way they are looked into is different and occurs through four steps known as description, discovery, composition, and enactment. A Web service that is empowered with several capacities, that are in fact operations to execute, has to know which capacity out of several it has to choose and then, trigger at run-time. For this purpose, this Web service takes into account the requirements like data and network that are put on each capacity it was empowered with. A feasibility discussion on the implementation of capacity-driven Web services is presented in this paper, as well.

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In this article, we focus on vehicular ad hoc networks. In such networks, sensor data are usually exchanged between vehicles to warn or inform the drivers when an event is detected (e.g., accident, emergency braking, available parking space, etc.).-In this article, we propose to aggregate and store these data in order to have a history of past events. We therefore use Flajolet-Martin sketches. Our goal is here to generate additional knowledge to assist drivers even if no event is detected.

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Les processus métiers constituent de plus en plus la colonne vertébrale des systèmes d'information modernes. Ils sont au cœur de la réorganisation des entreprises pour une meilleure intégration de leurs départements et de leurs personnels. Ils simplifient leur déploiement sur le web et supportent les coopérations interentreprises.

Cet ouvrage à destination d'un large public (étudiants, ingénieurs chercheurs) fait le point sur l'idée de processus métier. Il en établit les concepts fondamentaux, présente les principales notations utilisées (BPMN, XPDL, etc.), des éléments de conception et d'analyse (Petri Nets, UML, découverte de processus, Business Process Intelligence, etc.), illustre les architectures des systèmes de gestion de processus (intégrées : Nova Bonita, bibliothèques : Process Virtual Machine, etc.), la problématique des processus transactionnels et leur déploiement sur le web (modes de coopérations, services web, WSBPEL, etc.).

La plupart des chapitres sont illustrés par exemples et proposent des exercices.

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Keywords: SOA, Web services, Semantic Web services, WSMO, OWL-S, IRS-III, METEOR-S

Service oriented modeling is gaining acceptance among academia and industry as a computing paradigm for business and systems integration. Its strong decoupling between service provision and consumption enables much more flexible and cost-effective integration, within and across organizational boundaries, than existing middleware or workflow systems do. However, it also creates new requirements for handling effective service discovery, dynamic service interoperation and automation support for service composition. Web services have been emerging as the lead implementation of SOA upon the Web. The related technologies define common standards that ensure interoperability between heterogeneous platforms. Nevertheless, they fail in satisfying SOA requirements. Semantic Web services initiatives have then emerged with the objective of providing the foundation to overcome these requirements. The main idea is extending service description with machine interpretable information that software programs can reason over it. This chapter discusses how far Web services and semantic Web services initiatives satisfy SOA requirements.

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L'interopérabilité sémantique est une question importante, largement identifiée dans les technologies d’organisation et de l'information et dans la communauté de recherche en systèmes d'information. L’adoption large du Web afin d’accéder à des informations distribuées nécessite l'interopérabilité des systèmes qui gèrent ces informations. Des solutions et réflexions comme le Web Sémantique facilitent la localisation et l’intégration des données d'une manière plus intelligente par l'intermédiaire des ontologies. Il offre une vision plus sémantique et compréhensible du web. Pourtant, il soulève un certain nombre de défis de recherche. Un des principaux défis est de comparer et aligner les différentes ontologies qui apparaissent dans des tâches d'intégration. Le principal objectif de cette thèse est de proposer une approche d’alignement pour identifier les liens de correspondance entre des ontologies. Notre approche combine les techniques et les méthodes d’appariement linguistiques, syntaxiques, structurelles ou encore sémantiques (basées sur les instances). Elle se compose de deux phases principales : la phase d'enrichissement sémantique des ontologies à comparer et la phase d’alignement ou de mapping. La phase d'enrichissement est basée sur l'analyse des informations que les ontologies développent (des ressources web, des données, des documents, etc.) et qui sont associés aux concepts de l’ontologie. Notre intuition est que ces informations ainsi que les relations qui peuvent exister entre elles participent à l’enrichissement sémantique entre les concepts. A l’issue de la phase d'enrichissement, une ontologie contient plus de relations sémantiques entre les concepts qui seront exploitées dans la deuxième phase. La phase de mapping prend deux ontologies enrichies et calcule la similarité entre les couples de concepts. Un processus de filtrage nous permet de réduire automatiquement le nombre de fausses relations. La validation des correspondances est un processus interactif direct (avec un expert) ou indirect (en mesurant le degré de satisfaction de l’utilisateur). Notre approche a donné lieu à un système de mapping appelé ROMIE (Resource based Ontology Mapping within an Interactive and Extensible environment). Il a été expérimenté et évalué dans deux différentes applications : une application biomédicale et une application dans le domaine de l’apprentissage enrichi par les technologies (ou e-learning).

Keywords: Workflow, Web services, Entreprise virtuelle, Coopération

Dans cette HDR je présente mes recherches visant à définir des modèles et à développer des outils pour adresser des problématiques d’interopérabilité dans un cadre de coopération interentreprises de courte durée. Dans ce contexte, je propose une approche s’articulant autour de deux axes : la coopération basée sur les workflows et la coopération basée sur les services.

Dans le premier axe, i.e. la coopération de workflows, je me suis intéressé à l’interopérabilité sémantique, l’abstraction, l’appariement et l’interconnexion de workflows interentreprises. Pour ce faire, nous avons développé
 une technique pour la description sémantique de workflows,
 un algorithme pour l’abstraction comportementale de workflows basée sur les Symbolic Observation Graphs,
 une méthode d’appariement basée sur les sémantiques comportementales et métiers de workflows,
 une méthode d’interconnexion de workflows et une plateforme appelée CoopFlow pour l’intégration de systèmes de gestion de workflows hétérogènes.

Dans le second axe, i.e. la coopération de services, nos travaux concernent l’adaptation et le déploiement dynamiques d’applications basées sur les services. Pour ce faire, nous proposons de développer des modèles et méthodes pour améliorer l’expressivité de la description sémantique des services, l’efficacité et la pertinence de la découverte de service sensible au contexte et la (re)composition des services.

Keywords: Composite service mining, Service intelligence, Service analysis, Service validation, Service reengineering frameworks, Model driven reengineering, Workflow patterns

Web service compositions are becoming more and more complex, involving numerous interacting ad-hoc services. These services are often implemented as business processes themselves. By analysing such complex web service compositions one is able to better understand, control and eventually re-design them. Our contribution to this problem is a mining algorithm, based on a statistical technique to discover composite web service patterns from execution logs. Our approach is characterised by a “local” pattern’s discovery that covers partial results through a dynamic programming algorithm. Those locally discovered patterns are then composed iteratively until the composite Web service is discovered. The analysis of the disparities between the discovered model and the initial ad-hoc composite model (delta-analysis) enables initial design gaps to be detected and thus to re-engineer the initial Web service composition.

Keywords: Inter-enterprise collaboration, Flexible business process integration, Formalization of services composition

In the context of short-term cooperation, enterprises with complementary skills are dynamically interconnected according to their needs. To deal with requirements in such a cooperation, we present CoopFlow—a bottom-up approach that aims at providing a useful artifact for preservation of the privacy of partners, preestablished workflows and preestablished workflow management systems. CoopFlow consists of three steps: workflow abstraction and advertisement, workflow matching and interconnection, and workflow cooperation. To preserve the privacy of partners and allow them to retain a certain degree of confidentiality and safety of their internal workflows, the first step of the approach includes an abstraction procedure allowing a partial visibility of the partners’ workflows. The second step consists of interconnecting existing workflows of partners with complementary skills thanks to a matching procedure that allows checking both behaviors and business semantics of partners’ workflows. Finally, the last step of CoopFlow consists of controlling the inter-enterprise workflows cooperation. This step allows partners to integrate existing workflows and to check whenever they can cooperate and change their partners, which frequently leads to support of spontaneous, dynamic, and short-term cooperation. With this intent, we developed a platform that manages interoperability by integrating preestablished workflow management systems. The proof of concept is provided by integrating three heterogeneous and open workflow management systems in the CoopFlow platform.

Keywords: Mining, Reliability, Transactional Web service, Web services compositions

Ensuring composite services reliability is a challenging problem. Indeed, due to the inherent autonomy and heterogeneity of Web services, it is difficult to predict and reason about the behavior of the overall composite service (CS). Generally, previous approaches develop, using their modeling formalisms, a set of techniques to analyze the composition model and check “correctness” properties. Although powerful, these approaches may fail in some cases in order to ensure CS-reliable executions, even if they formally validate its composition model. This is because properties specified in the studied composition model remain assumptions that may not coincide with the reality (i.e., effective CS executions). Sharing the same issue, we present a reengineering approach that starts from CS executions log to improve its recovery mechanisms. Basically, we propose a set of mining techniques to discover CS transactional behavior from an event-based log. Then, based on this mining step, we use a set of rules in order to improve its reliability.

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Our work focus on data management in Vehicular Ad Hoc Networks (VANETs). Many pieces of information may be exchanged in such networks, for instance to warn drivers when a potentially dangerous event arises (accident, emergency braking, obstacle in the road, etc.) or to try to assist them (available parking spaces, traffic congestions, real-time traffi conditions, etc.). Existing systems only use the data exchanged to warn the driver. Then, the data is considered
obsolete and is deleted.
In this paper, we rather propose to aggregate the data once it becomes obsolete. Our objective is to produce additional knowledge to be used by drivers when no relevant data has been communicated by neighbouring vehicles. For example, it becomes so possible to dynamically detect potentially dangerous road segments or to determine the areas where the probability to find an available parking space is high when none has been received.

Keywords: Web Service discovery, Semantic and Capacity annotation, P2P, Web service registries

We are living a democratization of ubiquitous environments offering a great number of services. Different devices, having different technical capacities access those services. Such environment requires an effective service discovery approach. In this paper, we start with a study of some existing service discovery approaches. Then we introduce a semantic and context-aware service discovery approach. We propose to distribute services registries in a P2P network. The registries will be structured according to the capacities and semantics of the services. To describe capacity and semantic of a service, we annotate its WSDL description.

Keywords: Besoin informationnel, Modélisation de l’utilisateur, Intelligence économique, Problème décisionnel

Actuellement nous remarquons l’apparition de plus en plus d’outils dédiés à la démarche de l’intelligence économique. Ces outils, ont souvent pour but d’aider les entreprises à maîtriser leur organisation interne et à comprendre leur environnement par l’acquisition, le classement l’analyse et l’interprétation et l’exploitation systématiques d’informations. Ces outils sont classés en deux types. Le premier concerne les systèmes de gestion de l’information, qui permettent une manipulation massive des données opérationnelles et l’extraction de connaissances. Le deuxième type d’outils consiste à systématiser la collecte et l’analyse des informations à partir d’un environnement concurrentiel pour l’aide à la prise de décision stratégique. Nous ne nions pas l’importance de ces outils dans la réussite de la démarche de l’intelligence économique, surtout avec la surabondance de l’information. Cependant, la phase de l’analyse des besoins d’information n’a pas bénéficié d’autant de recherche et de réflexion de la part des chercheurs qui s’intéressent à l’intelligence économique. Dans ce papier nous mettons l’accent sur cette étape de définition des besoins qui constitue logiquement et chronologiquement la première étape dans la démarche de l’intelligence économique.

Keywords: Forum contextualisé, Personnalisation, Assistance, Informatique omniprésente

Nous présentons dans cet article l'intérêt de l'informatique omniprésente pour les forums dits contextualisés. Ces derniers permettent à une communauté de pratique d’échanger et de partager des expériences ou des situations vécues autour de documents pédagogiques qui classifient ces échanges. Ces forums sont une mine d’information qui peuvent particulièrement complémentaires aux formations classiques. Nous étudions ici des possibilités de l'informatique omniprésente pour exploiter ce type de forums afin de consolider la formation professionnelle à des procédures métier en assistant l’utilisateur à la mise en pratique sur le terrain. L'application développée et en cours d'expérimentation fonctionne ici essentiellement sur des smartphones.


We present in this paper the interest of ubiquitous computing for the so called contextualized forums. These forums allow communities of practice exchanging and sharing experiences or situations already lived by using learning documents to classify these exchanges. These forums contain a lot of information which contribute to improve classical training. We study here ubiquitous computing possibilities to use this type of forums in order to improve professional training to business process by helping the user to put into practice his/her acquisition. The developed application is being tested and works principally on smartphones.

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We present in this paper the interest of biquitous computing for the so called contextualized forums. These forums allow communities of practice exchanging and sharing experiences or situations already lived by using learning documents to classify these exchanges. These forums contain a lot of information which contribute to improve classical training. We study here ubiquitous computing possibilities to use this type of forums in order to improve professional training to business process by helping the user to put his/her acquisition into practice. The developed application is being tested and works mainly on smartphones.

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Web services are loosely-coupled and self descriptive applications. They are based on standards such as SOAP for message transport, WSDL for service description, and UDDI for service advertisement and discovery. Nevertheless, the lack of semantics in WSDL prevents automatic discovery and hence automatic invocation and composition. In our work, we are interested in extending existing approaches for the description of Semantic Web Services. Our proposed approach, Yet Another Semantic Annotation for WSDL (YASA4WSDL), is an extension of the W3C recommendation on semantics for Web services (SAWSDL) and use two types of ontologies: a Technical Ontology type containing concepts defining semantics of services, their QoS... and a Domain Ontology type containing the concepts defining the semantics of the business domain. We present how our approach is more expressive than the W3C recommendation and submissions to W3C on semantics of Web Services. We show via our implementation how to automatically generate from YASA4WSDL, descriptions like SAWSDL, OWL-S, or WSMO.

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Mobile technology provides many benefits to education. In this paper we describe the architecture of a system that allows people to search and retrieve information about its location and activities in a Campus, knowing about the resources available on its surroundings,
including buildings, classes, events and people.

Keywords: Services Web sémantiques (SWS), OWL-S, SAWSDL, WSMO

Le Web est en train de subir deux grandes évolutions à savoir les services Web et le Web sémantique. D’une part, l’évolution récente des technologies de l’Internet, guidée par le langage XML et ses technologies sous-jacentes, étend le rôle du Web d’un simple support d’information vers un intergiciel d’applications B2B. Cette nouvelle vague de l’Internet est guidée par les services Web. Les services Web sont des applications auto-descriptives, modulaires et faiblement couplées qui fournissent un modèle simple de programmation et de déploiement d’applications, basé sur des normes, et s’exécutant au travers de l’infrastructure Web [KAD 03]. La collaboration entre les services Web s’appuie sur une architecture à trois composants à savoir : le fournisseur, le client et l’annuaire. Le Web sémantique, quant à lui, est une extension du Web actuel, dans lequel les informations ont un sens bien défini afin de permettre aux ordinateurs et aux utilisateurs de travailler en coopération [BUR 01]. L’application du Web sémantique aux services Web a donné naissance aux services Web sémantiques (SWS). D’une manière automatisée, les utilisateurs et les agents logiciels devraient pouvoir découvrir, appeler, composer, et surveiller l’exécution des services Web.
Dans cet article, nous passons en revues les plus connues parmi elles à savoir OWL-S, SAWSDL et WSMO

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The traditional learning style theory is being used in the development of e-learning materials
progressively. Usually the process of working with learning styles begins with the development of tests or questionnaires that are focus on determining the preferences of students to learn, and then prepare the material according to them. But once the content is implemented there is no tool to measure or estimate if it complies with the desired learning styles.
We use a different approach and in this paper we perform the evaluation of existing pedagogical materials in order to determine the dominant learning style theory if there is any. Then the experimental result shows the classification of all the contents.

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Enterprise business procedures can be formalized by process models which must be correct in the sense that they do not affect negatively the functional objectives. The appropriate definition, analysis, checking and improvement of these models are indispensable before the deployment of the process model using a workflow management system. In this paper we present a new hybrid algorithm of workflow graph structural validation combining graph reduction and traversal mechanisms. Our algorithm will be compared to existing workflow structural checking approaches.

Keywords: XQuery, XML, Ontologies, SPARQL, RDF

This article presents an ongoing work about “information access” in XML collections using, not only the documents themselves, but also associated semantic information (metadata). We are building a system based on this approach. The system should also be context aware, this means that the information retrieved should be adapted to the user preferences and previous actions. As a case study, we apply our system to the Portuguese Emigration Museum.

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In a previous work in the context of information retrieval, XQuery was extended with an iterative paradigm. This extension helps the user getting the desired results from queries. In a related work, XQuery was also extended to allow the inclusion of SPARQL queries; this is useful when XML documents are associated with semantic RDF descriptions. However integrating SPARQL in XQuery queries makes the construction of queries more complex (although more powerful). To leverage this integration, we propose to apply the iterative paradigm to the 'SPARQL extension to XQuery'. In the paper this proposal is introduced and justified and a case study is presented.

Keywords: Process mediation, Space , Business process

Web service interactions lie in the core of SOA. Due to the autonomy, heterogeneity and continuous evolution of Web services, mediators are usually needed to support service interactions to overcome possible mismatches that may exist among business processes. In this paper, we introduce a space-based architecture for process mediator which considers both control-flow and data-flow, present possible mismatch patterns, and suggest how they can be automatically mediated. Our work can be used to perform runtime mediation and thus to facilitate service interactions.

Keywords: Biomedical and life science ontologies, Ontology mapping, Matchers, Similarity measures, Semantic web, Multi-agent systems

The increasing number of on-line accessible biological data sources has involved a growth of the number and the size of ontologies. This makes it increasingly valuable to map ontologies each other to determine which of their concepts are semantically related. Nowadays, developed tools are often semi-automatic and require the help of experts. Determining semantic relations between concepts is a difficult task, and the problem is still open. Several methods have been proposed in the literature. Existing tools for mapping concepts usually combine several methods, called matchers. In this paper, we propose a tool called OMIE (Ontology Mapping within an Interactive and Extensible environment) which uses and combines several matchers. OMIE is extensible, i.e. matchers could be added or inhibited, and is interactive, i.e. experts could validate or invalidate mappings as well as choose between mapping specific concepts or mapping the entire ontologies.

Keywords: Workflows interentreprises, Description sémantique, Abstraction, Coopération, Services web

La démocratisation de la technologie de l'information et des moyens de communication ouvre la voie aux entreprises pour réaliser, via la coopération, certaines tâches complexes qui n'étaient pas à leur portée, soit du fait de leur taille (il s'agit souvent des petites ou moyennes entreprises), soit du fait des compétences requises pour la réalisation des tâches en question. L'objectif de cette thèse est de proposer une approche sémantique pour la coopération des workflows. Cette approche doit supporter la description, l'abstraction et l'interconnexion de workflows. Pour ce faire, nous proposons premièrement de décrire les sémantiques métiers et comportementale des workflows. Une telle description permet le partage des données d'une part, et facilite l'interconnexion automatique d'autre part. Deuxièmement, les workflows sont publiés dans un annuaire commun. Nous proposons dans cette thèse des structures de donnés permettant de stocker efficacement les workflows dans l'annuaire. Troisièmement, afin de préserver le savoir-faire des différents partenaires participant à une coopération, nous proposons deux méthodes formelles pour l'abstraction des workflows. La première méthode se base sur des règles de réduction structurelle tandis que la deuxième se base sur la réduction du graphe représentant le comportement. Enfin, après l’abstraction et la publication de workflows, nous procédons dans la dernière étape à leur interconnexion. Pour faciliter cette interconnexion nous proposons un service de courtage pour la découverte des workflows. Ce service prend en compte les sémantiques métier et comportemental des workflows. Nous avons validé les solutions proposées à l'aide d'un prototype permettant l'interconnexion dynamique des compositions de services Web BPEL.


The democratization of information technology and the mean of communication opens the way for the companies to carry out, via the cooperation, certain complex tasks which were not with their range, either because of their size (they are often small or medium-sized companies),
or because of competences necessary for the realization of the tasks in question. The objective of this thesis is to propose a semantic approach for the workflows cooperation. This approach must support the description, the abstraction and the interconnection of workflows.
To reach this end, we firstly propose to describe business and behavioural semantics of workflows. Such a description allows sharing data on the one hand, and facilitates the automatic interconnection on the other hand. Secondly, the workflows are published in a common registry. We propose in this thesis structures of data allowing to effectively store the workflows in the directory. Thirdly, in order to preserve the know-how of the different partners taking part in a cooperation, we propose two formal methods for the abstraction of the workflows. The first method is based on structural reduction rules while the second is based on the reduction of the graph representing the behaviour. Lastly, after the abstraction and the publication of workflows, we proceed in the last step to their interconnection. To facilitate this interconnection we propose a broker for the discovery of the workflows. This broker takes into account business and behavioural semantics of the workflows. We validated the proposed solutions using a prototype allowing the dynamic interconnection of the compositions of Web services BPEL.

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Keywords: Cooperation, Visibility, Abstraction, Inter-organizational workflows

This work is in line with the CoopFlow approach dedicated for workflow advertisement, interconnection, and cooperation in the context of virtual enterprises. To support cooperation, one has to deal with the partners’ privacy respect. In fact, cooperation needs a certain degree of inter-visibility in order to perform interactions and data exchange. Nevertheless, cooperation may be employed as a cover to internalize the know-how of partners. To preserve privacy and autonomy, one must reduce workflow inter-visibility as tiny as the cooperation needs. We present in this paper a novel reduction-based method to preserve partners’ privacy. The principle of the algorithm is to get rid of all activities as well as control and data flows that don’t play any direct role into cooperation and don’t affect the behavior of the original workflow.

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Nowadays e-learning is considered as a strategic choice to support training and learning. This trend can be explained in part by some interesting e-learning’s characteristics. In fact, this learning mode offers more geographic and temporal flexibility. Furthermore, it is generally flexible, scalable and adaptable. Furthermore, with the adoption of the learning object paradigm it is possible to make a huge economy of time and money due to the possibilities of reuse and share. However, the quality aspect is not sufficiently considered. Thus, we propose an approach to evaluate content quality according to a set of criterions. In this paper we present the key elements necessary to make such as controls in a computable manner.

Keywords: Freshness control, Load balancing, Transaction conflict detection, Lazy replication

We present an approach for controlling the freshness of replicated XML documents. The main idea is that read-only transaction may accept to read stale data, provided they can express an upper bound on the staleness of the data they read. Controlling the freshness of data accessed by read-only transactions greatly improves load balancing since it allows for choosing a node for executing the transaction even if it is not perfectly fresh. Such a routing is based on the hability to detect wich parts of a document are likely of being updated by a given transaction. Due to the rich nature of XML, the problem is quite more complex than for relational SQL data. We present a new algorithm for conflict detection between transactions, needed to estimate freshness of data according to the missing transactions on a node. We also present new freshness measures, in order to take into account the structure/content nature of XML.

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Keywords: Composite learning objects, Iterative search

This article concerns the search and composition of learning objects (resources) that are available in the Web. Resources may be reused to compose new ones. As there are more and more collections of such objects, more sophisticated search and reuse techniques are needed. We assume that learning objects are structured, i.e. composed of other objects. We propose, in this paper, an iterative search paradigm where the user navigates over the structure of the learning objects and chooses the interesting ones to compose his/her own objects. To achieve this goal, the user has access to intermediate results of the navigational search. Our proposal is based on a query language that we informally describe here.

Keywords: XML, Structured Information Retrieval, Relevance estimation

This paper presents work in progress about Information Retrieval from collections of structured documents. The relevance of the document components is estimated using textual content and structural information. This information is given by a set of heuristics resulting from the analysis of the structure of the documents. This paper has focus on scientific articles. The proposed retrieval function is presented with a parametric form.

Keywords: XML, XQuery, Ontology, Dublin core, Metadata, SPARQL

In this paper, we address the use of data together with metadata to improve information access to XML document collections. We first emphasize the possibility to associate metainformation to parts of XML documents, and not only entire documents. This is accordingly to the fact that XML elements are considered as retrieval units. We, then, propose to explicitly search the desired information using a query language that is composed of XML search and metadata search. We focus our ideas in two types of metadata: Dublin Core and ontologies.

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Web services provide standard means to promote interoperability and extensibility among software applications, as well as to allow them to be combined in order to perform more complex operations. Therefore web services have to be described, published, discovered, invoked and composed. Within this process describing Web services using ontology will enhance service discovery. The "quality" of that discovery depends on the used algorithms and techniques. In this paper we propose a novel approach to enhance web service discovery based on, among others, requesters' preferences. First of all, we propose a way to express preferences of request elements. Then we introduce a matching algorithm that takes into account theses preferences in the discovery process.

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This paper discusses the added-value of combining users' preferences and Web services' capacities during the process of discovering the Web services that permit satisfying users' needs. The needs, preferences, and capacities vary over time, which requires tracking them using contextual details. Examples of needs include hotel booking and loan application. Examples of preferences include time of result delivery and interaction means. Examples of capacities include operations to perform at a certain time/place and non-functional characteristics of operations. In this paper, bringing Web services and users together is supported by an approach that develops respective ontologies for preferences and capacities, represents these latter with SAWSDL, and finally, matches them using a dedicated algorithm.

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Keywords: Pervasive learning, Context, Learning resources, User profile, Adaptation

Pervasive learning systems must define new mechanism to deliver the right resource, at the right time, at the right place to the right learner. This means that rich context information has to be considered: time, place, user knowledge, user activity, user environment and device capacity. As context is based on numerous information which may change frequently (coming from a collection of captors), a more aggregate view is defined to work on more abstract objects: the situations. Context information and situation information have to be widespread into all the models of learning systems: context preferences have to be handled in the learner model, well-adapted situation and situation scenarios have to be memorized in learning resource model. The adaptation process is enriched too.

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Keywords: Workflows interentreprises, Workflows coopératifs, Abstraction, Interconnexion, Coopération

L'évolution et l'automatisation des procédés d'entreprise ont favorisé l'émergence d'une concurrence plus intensive menant les entreprises à restructurer leurs procédés et leurs partenariats en mettant en commun leurs compétences respectives afin de réaliser des projets complexes qui ne sont pas à la portée d'une seule entreprise. On parle alors de coopération de workflows ou de workflows interentreprises. Force est de constater que les solutions proposées pour supporter les workflows inter-entreprises soit ne respectent pas le savoir-faire des entreprises, soit n'intègrent pas leurs workflows existants, soit ne préservent pas les systèmes de gestion de workflows pré-établis. Cette thèse s'intéresse à la coopération spontanée et dynamique des workflows interentreprises hétérogènes qui respecte leurs savoir-faire et préserve leurs workflows et systèmes de gestion de workflows existants. Afin d'atteindre cet objectif, nous proposons CoopFlow une nouvelle approche pour la coopération de workflows interentreprises permettant la publication, l'interconnexion et la coopération de workflows. Les entreprises commencent par publier leurs workflows au sein d'un annuaire. Pour préserver leurs savoir-faire et leur permettre de garder un certain degré de confidentialité et de sécurité de leurs workflows internes, nous proposons une procédure d'abstraction de workflow permettant une visibilité partielle des workflows des partenaires et de n'exposer à l'extérieur que les parties de leurs workflows jouant un rôle direct dans la coopération. La seconde étape de CoopFlow consiste à interconnecter des workflows existants de partenaires avec des compétences complémentaires grâce à une procédure de correspondance permettant de vérifier s'il existe des comportements communs des workflows de partenaires. Enfin, la dernière étape de CoopFlow consiste à contrôler et à surveiller la coopération de workflows interentreprises. Pour ce faire, nous avons développé une plateforme pour gérer l'interopérabilité au niveau système en intégrant les systèmes de gestion de workflows pré-établis. Deux architectures de coopération en fonction du degré de confiance entre les partenaires ont été définies: une architecture avec un contrôle centralisé lorsqu'il n'existe pas suffisamment de confiance entre les participants et une architecture distribuée lorsqu'il existe une certaine confiance entre les entreprises. Nous avons validé les solutions proposées à l'aide d'un prototype intégrant trois systèmes de gestion de workflows ouverts et hétérogènes.


The evolution and the automation of the business processes supported the emergence of a more intensive competition bringing the companies to restructure their processes and their partnerships by sharing their respective competences in order to carry out complex projects which are not with the range of only one company. One speaks then about cooperation of workflows or inter-organizational workflows. It is obvious that the solutions suggested to support the inter-organizational workflows either do not respect the know-how of the companies, or do not integrate their existing workflows, or do not preserve the pre-established workflow management systems. This thesis is interested in the spontaneous and dynamic cooperation of heterogeneous workflows which respects the know-how of the cooperating companies and preserves their existing workflows and workflow management systems. In order to achieve this goal, we propose CoopFlow a new approach for the inter-organizationel workflows' cooperation allowing publication, interconnection and ooperation of workflows. Companies start by publishing their workflows within a repository. To preserve their know-how and allow them to retain a certain degree of confidentiality and safety of their internal workflows, we propose an abstraction procedure allowing a partial visibility of the partners' workflows and to expose the parts of their workflows that play a direct role in cooperation. The second step of CoopFlow consists of interconnecting existing workflows of partners with complementary skills thanks to a matching procedure allowing to check if there are commun behaviors between partners's workflows. Finally, the last step of CoopFlow is to control and supervise the inter-organizational workflows's cooperation. With this intention, we developed a platform that manages interoperability by integrating pre-established workflow management systems. Two architectures of cooperation depending on the trust between partners are defined: an architecture with a centralized control when there is not sufficient trust between the participants and a distributed architecture when there is certain trust between partners. We validated the solutions suggested with a prototype integrating three heterogeneous and open existing workflow management systems.

Keywords: Pair-à-pair, Routage sémantique, Recherche d'informations

Le pair-à-pair (P2P) s'est imposé ces dernières années comme la technologie majeure d'accès à des ressources multimédia sur l'Internet. On peut classifier ces systèmes selon leur modèle de recherche sous-jacent qui peut être soit non structuré (propagation aléatoire des requêtes dans le graphe des pairs), soit structuré (propagation des requêtes selon une structure d'organisation des pairs). L'approche non structurée bien que moins efficace sur le plan du routage des requêtes offre l'avantage de respecter au mieux l'autonomie des pairs et de pouvoir supporter des langages de requêtes plus expressifs. L'efficacité de la recherche dans les systèmes non structurés peut être améliorée en introduisant de la sémantique dans le processus de routage des requêtes. Cette sémantique est généralement construite à partir du contenu des pairs mais peut également faire intervenir leur comportement passé (historique des requêtes). Nous présentons dans cet exposé un panorama des principaux algorithmes d'organisation et de routage sémantiques. Nous montrons notamment les travaux que nous menons dans le cadre des projets Rare et Respire et qui visent à combiner l'information sur le contenu des pairs et sur leur intérêt.


Peer-to-peer systems (P2P) are becoming a leading technology for multimedia resource access on the Internet. These systems can be classified depending on their underlying search model, which can be unstructured (queries are flooding in the peer’s network) or structured (queries are propagated according to a logical structure defined on peers). The unstructured model is less efficient but favours peer’s autonomy and supports more expressive query languages. Search efficiency in unstructured systems may be improved using some semantic inside the query process. This semantic is generally defined on peer’s content but may also used peer’s behaviour (query history). In this talk, we present a general overview of algorithms for semantic routing and organisation. We will give a focus on the work we have done in projects Rare and Respire combining semantic about peer’s content and behaviour.

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Our claim is that semantic metadata are required to allow a real reusing and assembling of learning objects. Our system is based on three models used to describe the domain, learners and learning objects. The learning object model is inspired from knowledge representation proposals. A learning object can be reused directly or can be combined with other learning objects using composition operators with well-defined semantic. Using these models we are able to define powerful search tools and an adaptive environment taking as input the learner model to construct the learning object to deliver. We are currently implementing this system using Sesame, an RDF
repository.

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In order to deal with the need of sharing learning objects within and across learning object repositories most of the recent work argue for the use of ontologies as a means for providing a shared understanding of common domains. But with the proliferation of a great number of different ontologies even for the same domain, it becomes necessary to provide a mapping process to perform interoperability. Although many efforts in ontology mapping have already been carried out, few of them use resources properties to generate relations between local concepts. Our approach exploits these properties and uses inference rules to produce correspondences between concepts from source and target ontology.

Keywords: Inter-organizational workflow, Service-oriented Architecture, Workflow views

This paper presents a novel approach to inter-organizational workflow cooperation. Our goal is to provide support for organizations which are involved in a shared but not pre-modeled cooperative workflow across organizational boundaries. Our approach allows for partial visibility of workflows and their resources, thus providing powerful ways for inter-organizational workflow configuration. Varying degrees of visibility of workflows enable organizations to retain required levels of privacy and security of internal workflows. Our presented view concept provides a high degree of flexibility for participating organizations, since internal structures of collaborative workflows may be adapted without changes in the inter-organizational workflows. Furthermore, we provide workflow participants with the freedom to change their workflows without changing their roles in the cooperation. This increases flexibility and is an important step to increase efficiency as well as reduction in costs for inter-organizational workflows. The presented approach is inspired by the Service-oriented Architecture (SOA). Accordingly, our approach consists of three steps: workflow advertisement, workflow interconnection, and workflow cooperation.

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Nowadays, myriad of Web-Based Educational Systems (WBES) exists, each of them storing their own learner's models and resources. Our work is a contribution to ontology-based WBES adaptability. As a first result, we have proposed a solution to measure the distance between two ontologies instances representing two learner profiles. the current one and a target one.

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In order to deal with the need of sharing learning objects within and across learning object repositories most of the recent work argue for the use of ontologies as a means for providing a shared understanding of common domains. But with the proliferation of much different ontology even for the same domain, it becomes necessary to provide a mapping process to perform interoperability. Two key issues must be addressed: the first one is to provide help to users describing and searching resources by organizing the knowledge covered by the learning resources and the second one is to define educational systems interoperability mechanisms to create a virtual learning space. Although many efforts in ontology mapping have already been carried out, few of them use resources properties to generate relations between local concepts and discover mapping dynamically.

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Les systèmes pair-à-pair (peer-to-peer, P2P, égal-à-égal) se sont popularisés ces dernières années avec les systèmes de partage de fichiers sur Internet. De nombreuses recherches concernant l’optimisation de la localisation des données ont émergé et constituent un axe de recherche très actif. La prise en compte de la sémantique du contenu des pairs dans le routage des requêtes permet d’améliorer considérablement la localisation des données. Nous nous concentrons sur l’approche PlanetP, faisant usage de la notion de filtre de Bloom, qui consiste à propager une signature sémantique des pairs (filtres de Bloom) à travers le réseau. Nous présentons cette approche et en proposons une amélioration : la création de filtres de Bloom dynamiques, dans le sens où leur taille dépend de la charge des pairs (nombre de documents partagés).

Peer-to-peer systems (P2P) have become popular these last years with sharing files on Internet. Much research has emerged concerning the optimization of data localization, and constitutes a very active research area. Taking into account semantic aspects improves considerably data localization. We based our study on the PlanetP approach, which uses the notion of Bloom Filter consisting on propagating peers’ semantic signatures (Bloom Filters) through the network. We present this approach and extend it with an improvement : the creation of dynamic Bloom Filters, their size depends on the load of peers (number of shared documents).

Keywords: Mapping d’ontologies, Interopérabilité sémantique, Systèmes multi-agents, Web sémantique, Ressources pédagogiques, EIAH

Afin de répondre au besoin de partage des ressources pédagogiques entre plusieurs entrepôts, plusieurs travaux récents proposent l'usage des ontologies pour représenter les connaissances partagées d’un domaine commun. Cependant, avec la prolifération d'ontologies différentes même pour le même domaine, il devient nécessaire de fournir un processus de mapping pour réaliser leur interopérabilité. Bien que de nombreux travaux sur le mapping d'ontologies aient été déjà effectués, peu d'entre eux utilisent les propriétés des ressources pour produire dynamiquement le mapping. L'algorithme que nous proposons dans cet article utilise les propriétés des ressources pour produire de nouvelles relations sémantiques entre les concepts du domaine. Cet enrichissement permet de générer des correspondances sémantiquement plus pertinentes. L'algorithme utilise la technologie multi-agent qui lui confère plus de flexibilité.


In order to deal with the need of sharing learning objects within and across learning object repositories most of the recent work argue for the use of ontologies as a means for providing a shared understanding of common domains. But with the proliferation of much different ontology even for the same domain, it becomes necessary to provide a mapping process to perform interoperability. Although many efforts in ontology mapping have already been carried out, few of them use resources properties to generate relations between local concepts and discover mapping dynamically. The algorithm that we propose in this paper uses resources properties to produce new semantic relations between concepts of the same domain. This enrichment allowed the generation of correspondences which are semantically more relevant. The algorithm uses the multi-agent technology for higher flexibility.

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The work we present here is in line with the CoopFlow approach dedicated for inter-organizational workflow cooperation that consists of workflow advertisement, workflow interconnection, and workflow cooperation. This approach is inspired by the Service-oriented Architecture and allows for partial visibility of workflows and their resources. Varying degrees of visibility of workflows enable organizations to retain required levels of privacy and security of internal workflows. Degrees of visibility are described in term of an abstraction of workflow's behavior using symbolic observation graph. The building of such graph uses the Ordered Binary Decision Diagram technique in order to represent and manage efficiently workflow abstraction within a registry. Advertised abstractions are then matched for workflow interconnections.

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This work is in line with the CoopFlow approach dedicated for workflow advertisement, interconnection, and cooperation in virtual organizations. In order to advertise workflows into a registry, we present in this paper a novel method to abstract behaviors of workflows into symbolic observation graphs (SOG). We present in addition an efficient algorithm for SOG matching, which is used for interconnecting workflows.

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BPEL is the most popular language for describing business process and business interaction based on Web services for inter-organizational cooperation. Nevertheless, BPEL requires a static binding of services to the flows. We propose in this paper a new approach enabling dynamic binding. This approach consists of, first, providing a high-level description of process, second, abstracting the process behavior using symbolic observation graphs and third providing an efficient algorithm for symbolic observation graphs matching which is used for binding dynamically business processes.

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Ce travail a été mené dans le cadre de l’Action Spécifique « Conception d’une plate-forme pour la recherche en EIAH » du département STIC du CNRS.

Keywords: Métadonnées, Ressources pédagogiques, Assemblage, Indexation

Le nombre de ressources pédagogiques disponibles sur l’Internet a considérablement augmenté ces dernières années et le problème de leur indexation et de leur recherche devient aujourd’hui crucial. Les normes et standards de métadonnées éducatives comme LOM et SCORM s’intéressent à ces problèmes mais ne les résolvent pas complètement à notre avis. Nous proposons dans cet article d’étendre ces standards en intégrant une description sémantique des ressources basée sur une ontologie du domaine de connaissance couvert. Une ressource se décrit par des prérequis, un contenu et une fonction d’acquisition. Cette description permet d’offrir des outils de recherche plus sophistiqués et favorise également la réutilisation. A cet effet, nous proposons de construire de nouvelles ressources par assemblage de ressources existantes. Cet assemblage se fait en définissant un graphe de composition construit à partir de ressources existantes et d’opérateurs de composition (séquence, parallèle, alternative). Pour donner encore plus de flexibilité dans la composition, nous introduisons la notion de ressource intentionnelle pour laquelle certaines ressources du graphe de composition peuvent être des requêtes intentionnelles sur la base des ressources. Nous montrons l’utilisation qui peut être faite de ce modèle de description sémantique au niveau du processus d’adaptation d’une ressource à un apprenant donné. Une notion de qualité de ressource est proposée qui permet notamment d’évaluer sa capacité à être réutilisée. Cette qualité peut être évaluée a posteriori par des métriques ou bien contrôlée a priori par du typage. Une implémentation de ce modèle a été faite en utilisant Sesame, une base de données RDF qui dispose d’un langage de requête appelé SeRQL.


The number of learning objects available on the Internet has significantly grown these last years and the problem of indexing and searching these learning objects is becoming crucial. Standards and norms of educative metadata such as LOM and SCORM have been proposed to handle this problem but in our opinion these proposals are not a satisfactory solution. In this paper, we propose to extend these standards with a semantic description of learning objects based on an ontology. A learning object is described by prerequisites, a content and an acquisition function. This allows defining powerful search tools and improves reusing. For reusing, we propose to define new learning objects by assembling existing objects. Assembling is specified by a composition graph composed by learning objects and composition operators (sequence, parallel, and alternative). In order to improve flexibility, we have introduced intentional objects. An intentional object is defined by a composition graph where (at least) one object has been replaced by an intentional query on the learning object repository. This model is used during the adaptive process of a learning object for a specific learner. We define a notion of quality on learning objects which mainly reflects their ability to reuse. This quality may be evaluated a posteriori using metrics on objects or controlled a priori using a type system. Our model has been implemented with Sesame, a RDF database which support SeRQL a powerful query language for RDF and RDFS.

Keywords: Adaptive learning system, Semantic metadata, Learning objects , Composition of learning objects

This approach proposes the creation and management of adaptive learning systems by combining component technology, semantic metadata, and adaptation rules. A component model allows interaction among components that share consistent assumptions about what each provides and each requires of the other. It allows indexing, using, reusing, and coupling of components in different contexts powering adaptation. Our claim is that semantic metadata are required to allow a real reusing and assembling of educational component. Finally, a rule language is used to define strategies to rewrite user query and user model. The former allows searching components developing concepts not appearing in the user query but related with user goals, whereas the last allow inferring user knowledge that is not explicit in user model.

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The emergence of new repositories of learning resources based on semantic technology raises the problem of ontologies interoperability. Learning resources are described by a set of metadata which may use different ontologies as referential. To handle the increasing number of heterogeneous ontologies it becomes necessary to develop automatic mapping approach. In this paper we propose to study technical solutions for ontologies handling through two use cases: (1) the comparison between a current learner profile and a target profile and (2) the search of learning resources among distributed repositories.