Ismael Bouassida Rodriguez

Threshold-based context analysis approach for ubiquitous systems

In ubiquitous computing environments, applications must be able to respond to dynamic context changes in order to provide suitable services to users. A promising solution consists of developing context aware applications. In this paper, we present an approach that supports context awareness in a ubiquitous computing environment. The proposed approach focuses on handling context information including context monitoring/acquisition, context interpretation, context classification, context storage, context analysis, and context aware adaptation. In this paper, we focus on context classification and context analysis. We present a context classification approach, which takes into account the context parameter evolution behavior. Then, we define a context analysis approach for ubiquitous computing environments. The proposed analysis approach aims at analyzing contextual information and detecting significant changes. The proposed analysis approach uses a threshold comparison technique in order to detect context changes. When relevant context changes are detected, the context aware application will be notified to trigger its suitable process dynamically in order to deal with the changes. Copyright

Towards a multi-scale modeling for architectural deployment based on bigraphs

With the evolution of distributed systems in size and complexity, software deployment remains a challenging task. Despite the existence of several approaches, most of them use informal models that lack a solid mathematic foundation. In this paper, we propose a bigraphical based approach for modeling and formalizing the deployment of distributed applications. This approach relies on multi-scale modeling. So, we start by modeling the first scale with a bigraph. This bigraph is enriched, through a series of reaction rules, until reaching the last scale that represents the deployment architecture.

Towards automated deployment of distributed adaptation systems

The development of a single software product is inefficient when groups of product are related since the development cost could be high. In addition, some products need to be self-adaptive in order to take into account the execution context changes. In this case, the implementation and management of the adaptation mechanisms variability is challenging especially for distributed systems due to the distribution issues. We address in this paper such issues by proposing a method for the software engineering of distributed adaptation systems. We propose an architectural model for distributed management of dynamic adaptation. We define also a graph grammar based approach to automate the tasks needed to construct and configure the adaptation system.

Designing energy efficient Smart Buildings in ubiquitous environments

Smart Buildings have been the subject of research for more than two decades. The different perspectives range from monitoring and controlling energy consumption. Indeed, energy efficiency is considered as one of the promising fields of applications of the Internet of Things. Since Smart Buildings are an important part of the smart grid, their energy efficiency is vital for the environment and global sustainability. In ubiquitous computing systems, designing Smart Building applications is a challenge since these applications must ensure a trade-off between energy consumption and occupants comfort especially in ubiquitous environments. In this paper, we focus on the design of a Smart Building application in ubiquitous computing systems. The Smart Building application is able to manage energy consumption while keeping the occupants comfort. We elaborate an illustrative scenario to demonstrate the usefulness of our work.

A formal method for modeling deployment architectures based on bigraphs

Software deployment is executed according a deployment architecture which describes the allocation of software components to its hardware hosts. In this paper, we tackle the issue of constructing correct deployment architectures for large distributed systems. Actually, such architectures should satisfy various constraints related to the software components and the target environment such as the hierarchical description of components, their connections and the resource constraints. We present a formal method for constructing deployment architectures using a formal language called BRS (Bigraphical Reactive System). This method provides a correct by design approach based on multi-scale modeling ensuring the correctness of the obtained deployment architectures. Following our approach, the designer starts by modeling the first scale architecture which is refined automatically by successively adding smaller scale components until obtaining the last scale deployment architecture.

IT Governance in Higher Education Institutions: A Systematic Literature Review

Information Technology IT is a very important aspect for higher education institutions HEI in both teaching, research and administration. The managers of those intuitions are more and more aware that IT is a strategic tool for their institutions. On the other hand, IT Governance is getting attention from the practitioner and research side, given the need to govern IT extending the organisations strategy and objectives into IT. IT Governance helps to set clear expectations, to gain participation, open communications, establish accountability and provide executive management oversight. Thus, it is important to consider IT Governance and the alignment with business strategy for HEI. In this article, authors present a Systematic Literature Review SLR on IT Governance in HEIs using a collection of scientific and non-conventional data grey literature. The motivation that drives this literature review is the further development of an IT Governance framework for Tunisian universities. This article aims to define the situation of the IT Governance in other countries. This article aims to provide a map of the state of the art of IT governance in HEI in various countries. Results show a mixed situation of IT Governance in HEIs. Some countries have the support of top level management to introduce IT Governance in HEIs by adopting regulatory frameworks and common laws. But other countries relay in their strong culture of IT Governance. The different case studies presented in this review show that there is no consensus on the IT Governance framework or standard to use in HEI. An important number of institutions are implementing COBIT or ISO best practices. In the other hand, some counties have developed their own frameworks. Results show there is no a single way to implement an IT Governance framework designed for HEI. However, it is also true that there are two mandatory aspects that are necessary to implement in IT Governance deployments: firstly, establishing a committee structure for IT assets and secondly, enable effective communication between the IT, the business and the stakeholders.

Describing correct deployment architectures based on a bigraphical multi-scale modeling approach ☆

Abstract In this paper, we propose a formal approach supporting the correct description of deployment architectures and their reconfigurations. According to defined models, correct deployment architectures are generated and one of them is selected to be deployed. This generation process is based on a multi-scale modeling approach adopting Bigraphs and Bigraphical Reactive Systems as a modeling language. In fact, the architecture of a scale is refined by adding the components of the next scale. Then, the obtained architecture is in turn refined and so on, until reaching the last scale. The transition between scales is performed through applying refinement rules. Based on correct by design, the refinement process is executed on a correct scale architecture (respects the defined models) by applying correct rules. So, we ensure that the generated scale architectures are correct. Finally, our approach is illustrated through the case study Smart Home.

A Bigraphical Modeling Methodology for Multi-scale Reconfigurable Systems

In this paper, we propose a multi-scale modeling methodology for software reconfigurable systems using the formal technique of Bigraphical Reactive Systems. This methodology provides a correct by design approach for the description of multi-scale architectures. It is based on a rule-oriented refinement process ensuring the transitions between scales. In fact, a first scale is defined by the designer. Then, it is refined by successively adding lower scale details. The applied rules respect the system constraints ensuring the correctness of the obtained scale architectures. Furthermore, we deal with the dynamic aspect of multi-scale systems by providing model-based rules of reconfigurations. We illustrate our approach with a Smart Buildings case study.

Designing an Analysis Procedure for Context Aware Applications in Ubiquitous Environments

Embedded and invisible computing resources are paving the way to a new paradigm known as ubiquitous computing. In this paradigm, more attention needs to be paid to the development of context aware applications. Several proposals for the development of these applications are based on a context awareness loop with four phases. First, monitoring context information (Collect). Second, analyzing the collected context information to detect changes (Analysis), third, deciding adaptation actions relative to the changes (Decide). Finally, executing the corresponding adaptation actions to deal accordingly with the changes (Act). In this paper, we discuss the Analysis phase. We propose an analysis approach that aims at detecting the context changes and raising notifications when changes occur. The analysis approach is based on thresholds and formalized through an analysis procedure that aims to facilitate the design of the analysis phase to develop context aware applications in ubiquitous environments. The analysis procedure is described by a set of steps used by the application designers to design context aware applications. In order to demonstrate the usefulness of our approach, we present a Smart Building case study and we illustrate the use of our analysis procedure through a Smart Building application scenario.

Towards a Decision Approach for Autonomic Systems Adaptation

The autonomic computing paradigm arises to tackle the complexity of todays dynamic heterogeneous and ubiquitous systems. The architecture of autonomic systems based on the MAPE-K loop dynamically adapts itself when the context changes. However, decisions within phases of the MAPE-K loop must be taken and therefore fit a suitable architecture. Ongoing researches take decisions upon context changes of the system and are a well studied topic in different fields, however, most of them use predefined decisions which do not cover all the contextual changes or decisions which support only a very specific type of application. In this work we propose an approach dealing with the decisions that must be taken within MAPE-K loop for system adaptation, in the context of autonomic computing. An exceptional architectural configuration of systems relies on consistent decisions taken by the analysis, planning and execution phases of the aforementioned loop. Autonomic systems undergo dynamic environment changes and therefore decisions lead the architectural configuration of the system to success or failure.