Abdelkrim Amirat

Towards an Approach for Building Reliable Architectures

Composing an application out of independent, reusable pieces has been a key challenge since the early days of software engineering. In this paper we examine some aspects of software architecture. We introduce our COSA+ model built in order to provide some enhancement in the COSA one. Our main contributions are the new structure given to an explicit connector, and the conceptual view of the different abstract levels used to define the applications architectures. Profits expected from these improvements are numerous; mainly we can quote the reduction of the production costs and the time to market, simplify the maintenance operations, and foresee supports for the evolution of the software architecture.

Towards a smart cloud gate for smart devices

Mobile Cloud Computing (MCC) is a new paradigm that has been introduced as an optimal solution for mobile technologys issues. Mobile technology aims to exploit the advantages offered by the Cloud in order to provide ubiquitous PC-like functionalities to mobile users. It is noteworthy that despite the benefits associated with the adoption of the Cloud by mobile technology the gate to the Cloud remains frozen. This means that mobile applications often use the same services without having an update of the novelty in Cloud. Thus, applications lack awareness of new services which are more advantageous in terms of features and qualities than the currently used ones. To enable mobile applications to exploit the Cloud intelligently, we propose Smart Mobile Cloud Architecture (SMCA). We consider this new architecture as referential allowing MCC users to have a full awareness of both contexts (Cloud and Mobile) at the same time. We introduce a new concept called Smart Cloud Gate (SCG), which aims to profile both mobile applications and the Cloud to extract knowledge that will be used as a criteria to select the appropriate services, which will be suggested to mobile applications and give each different application the appropriate view of the Cloud.

An experimental study to evaluate learning style personalisation in web-based adaptive e-learning systems

Learning style is one of the individual differences that play an important but controversial role in the learning process. On the other hand, previous research suggested that learning styles significantly affect student learning because they refer to how learners process and organise information. To this end, this paper presents an approach to integrate learning styles into adaptive e-learning hypermedia. The main objective was to develop a learning style based on adaptive e-learning hypermedia system (LS-AEHS) and assess the effect of adapting educational materials individualised to the students learning style. To achieve the main objectives, a case study was developed. An experiment between two groups of students was conducted to evaluate the impact on learning achievement. Inferential statistics were applied to make inferences from the sample data to more general conditions was designed to evaluate the new approach of matching learning materials with learning styles and their influence on students learning achievement. The findings support the use of learning styles as a guideline for adaptation into the adaptive e-learning hypermedia systems.

An Adaptive E-Learning System based on Student's Learning Styles: An Empirical Study

Personalized e-learning implementation is recognized as one of the most interesting research areas in the distance web-based education. Since the learning style of each learner is different one must fit e-learning with the different needs of learners. This paper presents an approach to integrate learning styles into adaptive e-learning hypermedia. The main objective was to develop a new Adaptive Educational Hypermedia System based on Honey and Mumford learning style model AEHS-H&M and assess the effect of adapting educational materials individualized to the students learning style. To achieve the main objectives, a case study was developed. An experiment between two groups of students was conducted to evaluate the impact on learning achievement. Inferential statistics were applied to make inferences from the sample data to more general conditions was designed to evaluate the new approach of matching learning materials with learning styles and their influence on students learning achievement. The findings support the use of learning styles as guideline for adaptation into the adaptive e-learning hypermedia systems.

An Adaptable and Generic Fault-Tolerant System for Distributed Applications

The work presented in this paper is inscribed within the framework of the autonomic computing which is an initiative started with IBM in 2001. Its final goal is to develop self-managed computing systems and to overcome the rapidly growing complexity problem. In this work, we treated the property self-healing of the autonomous systems on account of its importance in the development of the critical systems and with high availability requiring a self-protection against the software failures for ensuring the service continuity. This paper presents GAFTOS (Generic and Adaptable Fault-Tolerant System), a fault-tolerant system adaptable and generic for the distributed and dynamic component-based applications. We illustrate the expressive power of GAFTOS by encapsulating the following fault tolerance techniques in the sub-components of GAFTOS: primary-backup, message store, distributed backward-recovery and distributed checkpointing.

Developing a Conceptual Framework for Software Evolution Methods via Architectural Metrics

Because of the vital need for software systems to evolve and change over time in order to account for new requirements, software evolution at higher levels of modeling is considered as one of the main foundation within software engineering used to reduce complexity and ensure flexibility, usability and reliability. In similar studies for migration technique and software engineering, presenting a framework do not usually cover the specification of systems based on software architecture. In this paper, we specify a conceptual framework based on six explicit dimensions in respect to an architectural view-point as first class citizen. Indeed, sketching evolution relies upon identifying dimensions on which researchers try to answer while performing a new approach. The proposed model is based on answering What, Where, When, Who, Why and How questions. Analyzing these dimensions could provide a multiple choice to implement classification for architectural techniques. Further and using an example, these dimensions are quantified and then analyzed. This framework aims to provide a blueprint to guide researches to position architectural evolution approaches and maps them according a selected set of dimensions.

Context-driven composition for mobile applications: a metamodelling approach

Nowadays, the numbers of mobile applications (apps) is undeniably explosive. This phenomenon is likely to encourage the user to expect more or less the same app to be available on just about any kind of platforms, even when there are differences in the apps that run on such platforms. In order to better fulfil users expectations, understanding such differences - or heterogeneities - then becomes critical, as does resolving them, but is quite challenging. In this paper, we propose a technique for developing mobile device apps, through composition of existing homogeneous or heterogeneous software entities that are context-aware. As a key novelty, this technique uses a metamodelling approach in understanding and representing the differences, as well as commonalities, between reused software entities. In order to see the applicability and the effectiveness of this technique, a tool has been implemented to date, together with an application to a shop review app.

Adaptation with Four Dimensional Personalization Criteria Based on Felder Silverman Model.

Inthepastdecades,varioussystemshavebeenproposedtoprovidestudentswithabetterlearning environmentbytakingpersonalfactorsintoaccount.Learningstyleshavebeenoneofthewidely adoptedfactorsinthepreviousstudiesasareferenceforadaptinglearningcontentororganizingthe content.However,veryfewresearchersgiveanideaofmatchinge-mediawithappropriateteaching andlearningstylesandveryfewstudiesgiveanideaofwhichappropriatecombinationsofelectronic mediaandlearningstylesaremoreeffectivethanother.Inthispaper,theauthorsaimtoprototype anAFDPC-FSsystem(AdaptationwithFourDimensionalPersonalizationCriteriabasedonFelder Silvermanmodel).Theirsystempresentsageneralframeworkforcombiningandadaptingteaching strategies,learningstylesandelectronicmediaaccordingtoFelder-Silverman’slearningstylemodel. Anexperimentwasdesignedtoexploretheeffectofadaptationtodifferentlearningstyleswhen learningmaterialswerematchedwith learning styles. Inparticular itwas set up to seewhether therearesignificantdifferencesinlearningachievementandcognitiveloadbetweentwogroups,an experimentalgroupwhostudiedwithlearningstyle-fitversionandacontrolgroupwhostudiedwith non-fitversionofthesystemwithoutadaptationtolearningstyles.Theexperimentalresultsshowed thattheproposedsystemcouldimprovethelearningachievementsofthestudents.Moreover,itwas foundthatthestudents’cognitiveloadwassignificantlydecreased.

Selection algorithm of contextual software entities for composing adaptive mobile applications

The development of customized mobile applications basing on the composition mechanism (i.e. using existing software entities) has received a lot of attention in the last couple of years. The mobile devices heterogeneity shows that the portability requirements play an important role in the mobile applications developpement domain. Otherwise, mobile applications strongly depend on the execution environment features. Thereby, in order to make sure the correct deployment and the proper functioning of the composite mobile application it is necessary to ensure that their constituents are adaptable to the current context of the mobile device. To cope with this issue and due to the fact that several software entities can be used to implement the identified requirements for a desired mobile application, we propose in this paper a context-driven selection algorithm that aims at selecting the adaptive software entities among all corresponding ones. Also, it targets to determine the different possible composition paths to build customized mobile applications. To achieve this objective, we propose ontology based descriptions to define the context of the corresponding software entities and the execution environment.

Evolution Taxonomy for Software Architecture Evolution

Nowadays, architects are facing the challenge of proliferation of stakeholder requirements for preserving and ensuring the effectiveness of the software, by using software evolution as a key solution. Hence, in terms of landscaping evolution space there is a great need to define the thinking on which efforts to deal with this issue have been based. In this paper, we propose a framework for software architecture evolution taxonomy based on four structural dimensions. This framework could both position existing evolution models in the field and highlight gray areas for the future. Mapping over framework dimensions, a set of quality factors and an investigation including 67 studies are performed to assess the proposals. The results contain a number of relevant findings, including the need to improve software architecture evolution by accommodating predictable changes as well as promoting the emergence of operating mechanisms.