Alberto Portilla

Contract Based Behavior Model for Services Coordination

A key step towards consistent services coordination to provide non functional properties. In this sense, transactional properties are particularly relevant because of the business nature of current applications. While services composition has been successfully addressed, transactional properties have been main- ly provided by ad-hoc and limited solutions at systems’ back end. This paper proposes a flexible transactional behavior model for services coordination. We assume that given a flow describing the application logic of a service based application, it is possible to associate to it a personalized transactional behavior in an orthogonal way. This behavior is defined by specifying contracts and associating a well defined behavior to the activities participating in the coordination. Such contracts ensure transactional properties at execution time in the presence of exceptions.

Towards a transactional services coordination model

This paper proposes a flexible transactional behavior model for services coordination. We assume that given a flow describing the application logic of a service based application, it is possible to associate to it a personalised transactional behaviour in an orthogonal way. This behaviour is defined by specifying contracts and associating a well defined behaviour to the activities participating in the coordination. Such contracts ensure transactional properties at execution time in the presence of exceptions

A survey for analyzing transactional behavior in service based applications

This paper introduces key dimensions to analyze how transactional behavior is addressed in service based applications. In such applications, transactional behavior cannot be provided in the sense of DBMS ACID transactions. A review of existing concepts and requirements is required for proposing an approach that addresses them. Although several approaches concerning transactional behavior have been proposed, we think that it is necessary to clarify what is needed for current information systems and what remains as an open issue. In that sense, we propose some aspects for characterizing the transactional behavior and furthermore we introduce a critical review of current approaches

Finding and Analyzing Social Collaboration Networks in the Mexican Computer Science Community

Collaboration of peers is rather common in some scientific communities and is being facilitated with the advances in telecommunication and computer networking technologies. In this paper, we analyze the collaboration networks formed among Mexican computer science scholars\footnote{We preferred to use the term \emph{scholar} instead of \emph{researcher}, because the REMIDEC census is on PhD holders even if some of them are not actively involved in research activities.}, using social network analysis techniques. A series of measurements are performed to identify some patterns of collaboration both among individuals and among Mexican academic institutions. The data for our measurements was taken from two freely available sources: DBLP, a public digital library which indexes computer science related conferences and journals; and the census of Mexican scholars made by REMIDEC. In order to have an insight about the impact of publications, we used the CORE ranking for computer science conferences and journals. Our aim is to gain a better understanding of the working practices exhibited by the Mexican computer science community.

Mining Social Networks on the Mexican Computer Science Community

Scientific communities around the world are increasingly paying more attention to collaborative networks to ensure they remain competitive, the Computer Science (CS) community is not an exception. Discovering collaboration opportunities is a challenging problem in social networks. Traditional social network analysis allows us to observe which authors are already collaborating, how often they are related to each other, and how many intermediaries exist between two authors. In order to discover the potential collaboration among Mexican CS scholars we built a social network, containing data from 1960 to 2008. We propose to use a clustering algorithm and social network analysis to identify scholars that would be advisable to collaborate. The idea is to identify clusters consisting of authors who are completely disconnected but with opportunities of collaborating given their common research areas. After having clustered the initial social network we built, we analyze the collaboration networks of each cluster to discover new collaboration opportunities based on the conferences where the authors have published. Our analysis was made based on the large-scale DBLP bibliography and the census of Mexican scholars made by REMIDEC.

ROSE: A transactional services coordination engine

This paper introduces an adaptable transactional services coordination engine called ROSE. Different to existing services coordination engines, ROSE is able to combine different transactional contracts for executing a given coordination. Contracts capture application requirements as transactional properties derived from business rules. Inspired on separation of concerns approaches, our engine uses the notion of contract for expressing transactional properties separately from coordination specifications. In this way contracts can be defined and modified without modifying the coordination. The current version of ROSE is implemented on top of the open source coordination engine Bonita (www.objectweb.org) and it implements atomicity contracts useful for e-commerce applications.

Construire des applications fiables à base de services mobiles

Along with the emergence of ubiquitous computing there is a need for building reliable and secure applications that provide access to information in a continuous way. In such a context, access to resources and applications must be done in a flexible way through services that come up as a new paradigm for programming and organizing operations. In this paper we present an approach for building reliable mobile applications based on services oriented paradigm and the use of a contract based coordination model. Thanks to contracts, it is possible to associate a personalized behavior to a flow describing the logic of a mobile services based application. Contracts ensure transactional properties at execution time in the presence of exceptions and make applications aware of their execution context (QoS)