Henda Hajjami Ben Ghézala

Toward a comprehension view of web engineering

The paper is an attempt to explore some of the issues underlying Web applications development through the use of disciplined approaches. We first present the proposed Web engineering framework which suggests considering web engineering along four different views. Each view is capturing a particular relevant aspect of Web engineering. Motivations for developing the framework are three fold: (a) to help understand and clarify the Web engineering domain, (b) to guide in classifying and comparing both web applications and approaches and (c) to help researchers to identify new research axes. Next, we briefly present evaluation of 7 different Web-based approaches according to the Web engineering framework.

A Semantic Approach for the Modeling of Trajectories in Space and Time

The modeling and analysis of trajectories in space and time have been long a domain of social science studies since early developments of Time Geography. Early works have been mainly conceptual, but things are changing with recent advances in telecommunications and ubiquitous computing that allow representation of moving points and trajectories within spatial database systems. These have generated a large amount of research in formal and qualitative modeling of moving points, providing many opportunities to enrich emerging geometrical-based data structures with semantic approaches. This is the objective of the research presented in this paper that introduces a semantic-based model and manipulation language of trajectories. It is based on an algebraic Spatio-Temporal Trajectory data type (STT) endowed with a set of operations designed as a way to cover the syntax and semantics of a trajectory. The approach is formally presented and illustrated by a case study.

Cost estimation for product line engineering using COTS components

Economic models for reuse are very important to organizations aiming to develop software with large scale reuse approaches. In fact, the initial investment is so important that it can discourage managers to commit to those approaches. Thus, economic models can help them to assess the worthiness of such an investment. n nProduct Line Engineering (PLE) seems to be an attractive reuse approach in matter of product quality and time-to-market. Using Commercial Off The Shelf (COTS) in a PLE approach may have a positive impact. n nThis paper reports on the need for an economic model to quantify the predicted benefits of the PLE software development with the use of COTS components. We introduce a Model for Software Cost Estimation in a Product Line Engineering approach that we denote SoCoEMo-PLE 2. This latter includes the usage of COTS components. The potential benefits of the model are described.

COTS characterization model in a COTS-based development environment

Commercial off-the-shelf (COTS) components are more and more used in the new applications development. They promise to reduce cost and risks, and to ensure software higher quality. However, in practice, many problems are faced during the evaluation, selection and integration. Major causes of these problems are due to the lack of knowledge about COTS products, the ignorance of the available methods of evaluation, selection and integration, and the lack of guidance for choosing between these methods. Therefore, a COTS-based development environment (CEDE) turns out to be essential. In this perspective, we propose a survey of COTS characterizations and propose an extended model. The use of these attributes in a CEDE is specified by a scenario denoted by a multimodel process known as map formalism. The same development process is then illustrated with a map scenario focusing on the different types of selection/integration existing methods.

From intentions to software design using an intentional software product line meta-model

Software Product Line Engineering is a paradigm to develop software which allows the reducing of development costs for each individual product. In this kind of engineering, a family of related products is built out of a common set of core assets. The common characteristics and differences between products are managed in a systematic way. These differences are called variabilities. The variations analysis and the impact of the choices made for a required product are the reason of the main effort to design a product from the product line. In this paper, we try to argue that it is difficult to fully benefit of the SPL if it remains at the software level. The paper proposes a move towards a description of software product line in intentional terms, i.e. intentions and strategies to achieve business goals. We present ISPL, the model to describe intentional Software Product Line. We try through this Meta-models to present the different concepts which we will use in our approach. Thereafter, we propose our process to show how to use this model. This process combines the use of maps, visual techniques for the modeling of product lines, specially features diagrams and Meta-models.

Modeling Trajectories: A Spatio-Temporal Data Type Approach

Retrieving and analyzing trajectories favor the study of human behaviors in space and time. Although Time Geography has long proposed a conceptual framework for the interpretation of trajectory data, there is still a need for database and semantic models that support representation and manipulation. In fact, the concept of trajectory is rarely addressed as a sui generis data type that can be embedded in a database structure. This paper introduces an algebraic Spatio-Temporal Trajectory data type (STT) for the representation of object trajectory. The STT is an abstract data type endowed with a set of operations designed as a way to cover the syntax and semantics of a given trajectory. It is considered as a data structure that can be used for the design and implementation of spatio-temporal databases.

Web applications design with a multi-process approach

This paper deals with a new approach WApDM (Web Applications Design Method) for Web Applications Design. The WApDM is a multi-process approach whish covers all aspects should be considered during design of a Web application. The proposed approach is specified with the Map formalism. The use of the Map is three fold: (a) the Map process meta-model is adapted to the specification of complex methods, (b) Map introduces more flexibility in the method and (c) implicit information of the method are made explicit during the specification activity.

A Semantic-Based Data Model for the Manipulation of Trajectories: Application to Urban Transportation

Nowadays, the increasing development of positioning and wireless communication technologies favors a better real-time integration and manipulation of large spatial databases. This offers many new opportunities for the development of trajectory databases, but a number of research challenges are still open as the generated information is often unstructured, continuous, large and sometimes unpredictable. The research presented in this paper develops a modeling approach that integrates the semantic, spatial and temporal dimensions when representing spatial trajectories at the abstract and logical levels. A data manipulation language that supports the querying and analysis of large trajectory databases is also proposed. The spatial database model is based on algebraic data types, and a prototype is developed on top of the DBMS PostgreSQL/PostGIS. The whole approach and the prototype development have been experimented and applied to benchmark transportation data derived from an origin-destination survey in the region of Quebec in Canada.

Management of socio-cultural knowledge using an ontology-based socio-cultural user profile in a computer-supported collaborative learning environment

Computer Supported Collaborative Learning (CSCL) is a pedagogical approach wherein learning takes place via social interaction using a computer or through the Internet. This kind of learning is characterized by the sharing and construction of knowledge among participants. This knowledge is shared through communication technologies embedded in CSCL systems. However in the context of globalization and the expansion of the internet and Information Technology (IT), communication becomes intercultural, so a complex and important dimension is added to CSCL and brings a new type of knowledge, socio-cultural knowledge, that needs to be shared and then presents new challenges. Therefore, in intercultural collaborative learning settings, we need to get and ensure better interaction, to get better learning. Better interaction is reached by promoting motivation to learn in groups, and this is obtained by enhancing user satisfaction which is achieved by the development of tailored CSCL tools to each user according to her socio-cultural background. Adapting the CSCL system to the culture of each participant will allow and facilitate group decision-making in the collaborative learning activity, as we take into account socio-cultural specificities of each learner, this latter will be more comfortable with the system and the other learners, and can collaborate with them to make decisions about the collaborative solution. So this article addresses the challenges started up by this context, which is how to consider socio-cultural specificities of each learner.

Towards a Decision Support System for Security Analysis

The work presented in the context of this paper is to develop a decision support system for security analysis called Adast. Adast is based on Case-Based Reasoning (CBR) and ontologies to help capitalize and exploit the knowledge on railroad accidents from our field of application. The advantage of this approach, based primarily on case-based reasoning and ontologies, lies not only on the capitalization of knowledge from experience feedback, but also on benefit in order to provide assistance to domain experts in their crucial task of analyzing and Improving security. In this paper, we will present the first realized works of Adast.