Service composition has risen from the need to make information systems more flexible and open. The Service Oriented Architecture has become the reference architecture model for applications carried by the impetus of Internet (Web). In fact, information systems are able to expose interfaces through the Web which has increased the number of available Web services. On the other hand, with the emergence of the Web 2.0, service composition has evolved toward web users with limited technical skills. Those end-users, named Y generation, are participating, creating, sharing and commenting content through the Web. This evolution in service composition is translated by the reference paradigm of Mashup and Mashup editors such as Yahoo Pipes! This paradigm has established the service composition within end users community enabling them to meet their own needs, for instance by creating applications that do not exist. Additionally, Web 2.0 has brought also its social dimension, allowing users to interact, either directly through the online social networks or indirectly by sharing, modifying content, or adding metadata. In this context, this thesis aims to support the evolving concept of service composition through meaningful contributions. The main contribution of this thesis is indeed the introduction of the social dimension within the process of building a composite service through end users' dedicated environments. In fact, this concept of social dimension considers the activity of compositing services (creating a Mashup) as a social activity. This activity reveals social links between users based on their similarity in selecting and combining services. These links could be an interesting dissemination means of expertise, accumulated by users when compositing services. In other terms, based on frequent composition patterns, and similarity between users, when a user is editing a Mashup, dynamic recommendations are proposed. These recommendations aim to complete the initial part of Mashup already introduced by the user. This concept has been explored through (i) a step-by-step Mashup completion by recommending a single service at each step, and (ii) a full Mashup completion approaches by recommending the whole sequence of services that could complete the Mashup. Beyond pushing a vision for integrating the social dimension in the service composition process, this thesis has addressed a particular constraint for this recommendation system which conditions the interactive systems requirements in terms of response time. In this regard, we have developed robust algorithms adapted to the specificities of our problem. Whereas a composite service is considered as a sequence of basic service, finding similarities between users comes first to find frequent patterns (subsequences) and then represent them in an advantageous data structure for the recommendation algorithm. The proposed algorithm FESMA, provide exactly those requirements based on the FSTREE structure with interesting results compared to the prior art. Finally, to implement the proposed algorithms and methods, we have developed a Mashup creation framework, called Social Composer (SoCo). This framework, dedicated to end users, firstly implements abstraction and usability requirements through a workflow-based graphic environment. As well, it implements all the mechanisms needed to deploy composed service starting from an abstract description entered by the user. More importantly, SoCo has been augmented by including the dynamic recommendation functionality, demonstrating by the way the feasibility of this concept.

This thesis is based on longitudinal data of the Swedish population provided byStatistics Sweden and is conducted on behalf of the Institute for Analytical Sociology.The focus is on investigating the effectiveness of a frequent sequence miningmethod called constrained Sequential PAttern Discovery using Equivalence classes(cSPADE). The method is applied to data on segregation within workplaces, specificallyreasons for Swedish employees moving to more segregated workplaces. Thethesis found that no unique pattern of age, gender, education, unemployment, income,workplace size or foreignness index explain why a Swedish employee movesto a more segregated workplace. Evaluating the algorithm, it was found that thenumber of observations need to be smaller or an alteration of the algorithm needsto be done to reduce the process time for this specific data set.

Le paradigme de service dans les nouvelles technologies de l’information et de communication est omniprésent, si bien qu’on parle de science des services. Les services Web sont définis dans le cadre des architectures orientées services (SOA) qui permet de distinguer le fournisseur de service, le répertoire de services, et enfin le consommateur du service. Cette distinction permet de créer de nouveaux services en composant des services déjà existants. Cependant, la composition de services est principalement bénéfique aux utilisateurs expérimentés comme les développeurs de logiciels car elle requiert un niveau technique élevé. Par opposition, la tendance actuelle traduite par l’émergence du Web2.0, vise à permettre aux utilisateurs du Web de créer leurs propres services à travers les environnements de Mashup, ou de collaborer et de capitaliser des connaissances à travers les réseaux et les médias sociaux. Nous croyons qu’il existe un grand potentiel pour “démocratiser” la composition de services dans de tels contextes. L’émergence du Web 2.0, basé sur des paradigmes tels que le contenu généré par l’utilisateur (UGC, Mashups) et le web social, constitue, une opportunité intéressante pour améliorer la productivité de services par l’utilisateur final et accélérer son processus créatif en capitalisant les connaissances générées par tous les utilisateurs. Dans ce contexte, cette thèse vise à soutenir l'évolution du concept de composition de services par le biais de contributions significatives. La principale contribution de cette thèse est en effet l'introduction de la dimension sociale dans le processus de construction d'un service composite à travers les environnements dédiés aux utilisateurs finaux. Ce concept considère l'activité de composition de services (création d'un Mashup) comme une activité sociale. Cette activité révèle les liens sociaux entre les utilisateurs en fonction de leur similitude dans le choix et la combinaison des services. Ces liens permettent de diffuser d'expertise de composition de services. En d'autres termes, sur la base des schémas fréquents de composition, et la similitude entre les utilisateurs, lorsqu’un utilisateur est en train d’éditer un Mashup, des recommandations dynamiques lui sont proposées. Ces recommandations visent à compléter la première partie de Mashup déjà mis en place par l'utilisateur. Ce concept a été exploré à travers (i) la complétion de Mashup étape par étape en recommandant à chaque étape un service unique, et (ii) la complétion totale de Mashup en recommandant la séquence complète de services qui pourraient le compléter. Au-delà de l’introduction de la dimension sociale dans le processus de composition de services, cette thèse a adressé une contrainte particulière du système de recommandation liée aux exigences des systèmes interactifs en termes de temps de réponse. À cet égard, nous avons développé des algorithmes robustes et adaptées aux spécificités de notre problème. Alors qu’un service composite est considéré comme une séquence de service, la recherche de similarités entre les utilisateurs revient d'abord à trouver des modèles fréquents, puis de les représenter dans une structure de données avantageuse pour l'algorithme de recommandation. L’algorithme proposé FESMA répond à ces exigences en se basant sur la structure FSTREE et offrant des résultats intéressants par rapport à l'art antérieur. Enfin, pour mettre en œuvre les algorithmes et les méthodes proposées, nous avons développé un environnement de création de Mashup, appelé ‘Social Composer’ (SoCo). Cet environnement, dédié aux utilisateurs finaux, respecte les critères d'utilisation en se basant sur le workflow graphique. En outre, il met en œuvre tous les mécanismes nécessaires pour déployer le service composé à partir d'une description abstraite introduite par l'utilisateur. De plus, SoCo a été augmentée en y incluant la fonctionnalité de recommandation dynamique, démontrant la faisabilité de ce concept / Service composition has risen from the need to make information systems more flexible and open. The Service Oriented Architecture has become the reference architecture model for applications carried by the impetus of Internet (Web). In fact, information systems are able to expose interfaces through the Web which has increased the number of available Web services. On the other hand, with the emergence of the Web 2.0, service composition has evolved toward web users with limited technical skills. Those end-users, named Y generation, are participating, creating, sharing and commenting content through the Web. This evolution in service composition is translated by the reference paradigm of Mashup and Mashup editors such as Yahoo Pipes! This paradigm has established the service composition within end users community enabling them to meet their own needs, for instance by creating applications that do not exist. Additionally, Web 2.0 has brought also its social dimension, allowing users to interact, either directly through the online social networks or indirectly by sharing, modifying content, or adding metadata. In this context, this thesis aims to support the evolving concept of service composition through meaningful contributions. The main contribution of this thesis is indeed the introduction of the social dimension within the process of building a composite service through end users’ dedicated environments. In fact, this concept of social dimension considers the activity of compositing services (creating a Mashup) as a social activity. This activity reveals social links between users based on their similarity in selecting and combining services. These links could be an interesting dissemination means of expertise, accumulated by users when compositing services. In other terms, based on frequent composition patterns, and similarity between users, when a user is editing a Mashup, dynamic recommendations are proposed. These recommendations aim to complete the initial part of Mashup already introduced by the user. This concept has been explored through (i) a step-by-step Mashup completion by recommending a single service at each step, and (ii) a full Mashup completion approaches by recommending the whole sequence of services that could complete the Mashup. Beyond pushing a vision for integrating the social dimension in the service composition process, this thesis has addressed a particular constraint for this recommendation system which conditions the interactive systems requirements in terms of response time. In this regard, we have developed robust algorithms adapted to the specificities of our problem. Whereas a composite service is considered as a sequence of basic service, finding similarities between users comes first to find frequent patterns (subsequences) and then represent them in an advantageous data structure for the recommendation algorithm. The proposed algorithm FESMA, provide exactly those requirements based on the FSTREE structure with interesting results compared to the prior art. Finally, to implement the proposed algorithms and methods, we have developed a Mashup creation framework, called Social Composer (SoCo). This framework, dedicated to end users, firstly implements abstraction and usability requirements through a workflow-based graphic environment. As well, it implements all the mechanisms needed to deploy composed service starting from an abstract description entered by the user. More importantly, SoCo has been augmented by including the dynamic recommendation functionality, demonstrating by the way the feasibility of this concept.