Browsing by Author "Mezghiche, Mohamed"

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An approach for formal verification of updated Java bytecode programs
(CEUR-WS, 2015) Lounas, Razika; Mezghiche, Mohamed; Lanet, J.-L.
This paper deals with formal specification and verification of Java bytecode update. Programs update for Java applications has gained a wide interest since it is used for several purposes: transforming semantics of a program, adding features to a program or performing optimizations. In this paper, we focus on program transformations for Java programs at the bytecode level. Because these transformations may introduce errors, our goal is to provide a formal way to verify the update and establish its correctness. Our approach for formal specification and verification of updated Java bytecode programs is based on four ingredients: a formal interpretation of the semantics of update operations, a functional representation of bytecode, bytecode annotation and predicate transformation calculus.We use the concept of Hoare predicate transformation to derive a specification of an annotated bytecode. Annotations are used to express update operations within the code. A functional representation is used to model annotations and bytecode. The approach derives then a new specification for the annotated bytecode using a weakest precondition calculus defined to deal with update operations. Verification conditions are then generated and proved to establish the correction of the update
Bi-objective ant colony optimization approach to optimize production and maintenance scheduling
(Elsevier, 2010) Mezghiche, Mohamed; Amodeo, L.; Yalaoui, F.; Berrichi, A.
This paper presents an algorithm based on Ant Colony Optimization paradigm to solve the joint production and maintenance scheduling problem .This approach is developed to deal with the model previously proposed in [3] for the parallel machine case. This model is formulated according to a bi- objective approach to find trade-off solutions between both objectives of production and maintenance. Reliability models are used to take in to account the maintenance aspect. To improve the quality of solutions found in our previous study, an algorithm based on Multi-Objective Ant Colony Optimization (MOACO) approach is developed. The goal is to simultaneously determine the best assignment of production tasks to machines as well as preventive maintenance (PM) periods of the production system, satisfying at best both objectives of production and maintenance. The experimental results show that the proposed method out performs two well-known Multi-Objective Genetic Algorithms (MOGAs): SPEA 2and NSGAII
Bi-objective optimization algorithms for joint production and maintenance scheduling : application to the parallel machine problem
(Springer, 2009) Berrichi, A.; Amodeo, L.; Yalaoui, F.; Châtelet, E.; Mezghiche, Mohamed
A case study in combining formal verification and model-driven engineering
(CEUR-WS, 2012) Djeddai, Selma; Mezghiche, Mohamed; Strecker, Martin
Formal methods are increasingly used in software engineering. They offer a formal frame that guarentees the correctness of developments. However, they use complex notations that might be difficult to understand for unaccustomed users. It thus becomes interesting to formally specify the core components of a language, implement a provably correct development, and manipulate its components in a graphical/ textual editor. This paper constitutes a first step towards using Model Driven Engineering (MDE) technology in an interactive proof development. It presents a transformation process from functional data structures, commonly used in proof assistants, to Ecore Models. The transformation is based on an MDE methodology. The resulting meta-models are used to generate graphical or textual editors. We will take an example to illustrate our approach: a simple domain specific language. This guiding example is a Java-like language enriched with assertions
A case study in combining formal verification and model-driven engineering
(CEUR-WS, 2012) Djeddai, S.; Mezghiche, Mohamed; Strecker, M.
Formal methods are increasingly used in software engineering. They offer a formal frame that guarentees the correctness of developments. However, they use complex notations that might be difficult to understand for unaccustomed users. It thus becomes interesting to formally specify the core components of a language, implement a provably correct development, and manipulate its components in a graphical/ textual editor. This paper constitutes a first step towards using Model Driven Engineering (MDE) technology in an interactive proof development. It presents a transformation process from functional data structures, commonly used in proof assistants, to Ecore Models. The transformation is based on an MDE methodology. The resulting meta-models are used to generate graphical or textual editors. We will take an example to illustrate our approach: a simple domain specific language. This guiding example is a Java-like language enriched with assertions.
Classification de structures arborescentes : cas de documents XML = Classification of tree structures: case of the XML documents
(2009) Ait El hadj, Ali; Mezghiche, Mohamed; Souam, F.
A cooperative approach based on local detection of similarities and discontinuities for brain MR images segmentation
(2020) Bennai, Mohamed Tahar; Smaine, Mazouzi; Guessoum, Zahia; Mezghiche, Mohamed; Cormier, Stephane
This paper introduces a new cooperative multi-agent approach for segmenting brain Magnetic Resonance Images (MRIs). MRIs are manually processed by human radiology experts for the identification of many diseases and the monitoring of their evolution. However, such a task is time-consuming and depends on expert decision, which can be affected by many factors. Therefore, various types of research were and are still conducted to automate MRI processing, mainly MRI segmentation. The approach presented in this paper, without any parametrization or prior knowledge, uses a set of situated agents, locally interacting to segment images according to two main phases: the detection of discontinuities and the detection of similarities. An implementation of this approach was tested on phantom brain MR images to assess the results and prove its efficiency. Experimental results ensure a minimum of 89% Dice coefficient with increasing values of the noise and the intensity non-uniformity
A distance based approach for link analysis in xml information retrieval
(2015) Mataoui, Mhamed; Mezghiche, Mohamed
In the present paper, we consider the problematic of efficiently generating ranked results in the XML IR context, by incorporating the link source of evidence. Despite of their popularity in the Web, only few research have exploited links to handle XML IR tasks. In contrast, we propose a new query-dependent link analysis approach based on a spreading-activation process that propagates relevance score through the two types of XML links, hierarchical and navigational, to compute a link score for each retrieved XML element. This propagation process depends on two features: the distance between elements and the type of the links separating these elements. The assigned link score is then combined with the content-based score to compute a new score used to re-rank the initial returned list of XML elements.We conducted a series of experiments based on INEX 2007 and 2009 test collections. Evaluation showed significant improvement compared to baseline runs and previous obtained results. These evaluation tests were followed by cross-validation test, which confirmed the robustness of our approach
A distributed intrusion detection model based on a society of intelligent mobile agents for ad hoc network
(IEEE, 2011) Bourkache, G.; Mezghiche, Mohamed; Tamine, K
The evolution of wireless network technologies and the recent advances in mobile computing hardware have made possible the introduction of various applications in mobile adhoc networks. Not only is the infrastructure of these networks inherently vulnerable but they have increased requirements regarding their security as well. As intrusion prevention mechanisms, such as encryption and authentication, are not sufficient regarding security, we need a second line of defence, Intrusion Detection. The focus of this paper is on distributed and intelligent intrusion detection. We propose a model for building a distributed and behavioural intrusion detection system by using a classification method.
Evaluation of e-Government information systems agility in the perspective of sustainability
(Springer, 2011) Mezghiche, Mohamed; Khadraoui, Abdelaziz; Imache, Rabah; Aggoune, Soumia
Agility and sustainability are two relatively recent concepts which interest more and more the researchers in management and information systems. However, in spite of their growing popularity in all fields of knowledge, the conceptualization of these concepts is not achieved yet in the e-government field, and then remains completely open. The aim of this paper is to conceptualize them while flying over the existing state of the art dealing with the principle approaches of agility and sustainability of systems; and then to contribute to these works by suggesting a components oriented-method for the evaluation of e-government information systems agility in the perspective of their sustainability. This method is based on Methods Engineering discipline and thus, it is built in the form of components guiding the process of evaluation. Electronic Government and the Information Systems Perspective Electronic Government and the Information Systems Perspective Look Inside Other actions Export citation About this Book Reprints and Permissions Add to Papers Share Share this content on Facebook Share this content on Twitter Share this content on LinkedIn
Evidential-Link-based Approach for Re-ranking XML Retrieval Results
(2014) Mataoui, Mhamed; Mezghiche, Mohamed; Sebbak, Faouzi; Benhammadi, Farid
In this paper, we propose a new evidential link-based approach for re-ranking XML retrieval results. The approach, based on Dempster-Shafer theory of evidence, combines, for each retrieved XML element, content relevance evidence, and computed link evidence (score and rank). The use of the Dempster–Shafer theory is motivated by the need to improve retrieval accuracy by incorporating the uncertain nature of both bodies of evidence (content and link relevance). The link score is computed according to a new link analysis algorithm based on weighted links, where relevance is propagated through the two types of links, i.e., hierarchical and navigational. The propagation, i.e. the amount of relevance score received by each retrieved XML element, depends on link weight which is defined according to two parameters: link type and link length. To evaluate our proposal we carried out a set of experiments based on INEX data collection
Experiments on Page Rank Algorithm in the XML Information Retrieval Context
(2009) Mataoui, Mhamed; Boughanem, Mohand; Mezghiche, Mohamed
In this paper we present two adaptations of the PageRank algorithm to collections of XML documents and the experimental results obtained for the Wikipedia collection used at INEX-1 2007. These adaptations to which we referred as ldquoDOCRANK and TOPICAL_docrankrdquo allow the re-rank of the results returned by the base run execution to improve retrieval quality. Our experiments are performed on the results returned by the three best ranked systems in the ldquoFocusedrdquo task of INEX 2007. Evaluations have shown improvements in the quality of retrieval results (improvement of some topics is very significant, eg: topic 491, topic 521, etc.). The best improvement achieved in the results returned by the DALIAN2 university system (global rate obtained for the 107 topics of INEX 2007) was about 3.78%
Exploiting Link Evidence to Improve XML Information Retrieval
(2010) Mataoui, Mhamed; Mezghiche, Mohamed; Boughanem, Mohand
In this paper, we examine how link evidence can be exploited in XML information retrieval (XML IR) field. We experimented some well-known link analysis algorithms, i.e., PageRank, HITS and SALSA, in XML IR context. We propose to re-rank XML elements by combining their topical score with their link score computed according to one of the above algorithms. These experiments, performed on the Wikipedia collection provided by INEX, showed that the use of links in topical context improves the retrieval accuracy
Exploiting links to improve search in XML documents
(Digital Information Research Foundation, 2018) Berchiche-Fellag, Samia; Mezghiche, Mohamed
This paper describes an approach that ex-ploits links in XML retrieval. The proposed approach con-sists of reranking the set of documents returned for agiven query by considering three sources of evidencenamely, the relevance scores w.r.t query of a documentneighbours, the text of the anchor links, and the docu-ment title tag. Our approach is evaluated on INEX 2006collection. The results showed significant improvementsof the retrieval performances
Formal Methods for Internet of Things: a Concise Classification
(Université M’hamed Bougara de Boumerdes : Faculté des Sciences, 2024) Talamali, Ibtissem; Lounas, Razika; Mezghiche, Mohamed
Formal methods in dynamic software updating : a survey
(Inderscience, 2019) Lounas, Razika; Mezghiche, Mohamed; Lanet, Jean Louis
Dymanic software updating DSU consists in updating running programs on-the-fly without any downtime that leads to systems unavailability. The use of DSU in critical applications raises several issues related to update correctness. Indeed, an erroneous dynamic update may introduce safety vulnerabilities and security breaches. In this perspective, the use of formal methods has gained a large interest since they respond to the high need of rigor required by such applications. Several frameworks were developed to first express update correctness which is based on several criteria. Then, the proposed formalisms are used to specify DSU systems, express correctness criteria and establish them. In this paper, we present a review of researches on the application of formal methods to DSU systems. We give a classification of systems according to the paradigms of programming languages and then we explain the correctness criteria and categorise the articles regarding the approaches of formalisation to establish the correctness. This information is useful to help ongoing researches in having an overview on the application of formal methods in DSU
A formal verification of dynamic updating in a Java-based embedded system
(Inderscience, 2017) Lounas, Razika; Mezghiche, Mohamed; Lanet, Jean-Louis
Dynamic software updating (DSU) consists in updating running programs on the fly without any downtime. This feature is interesting in critical applications that must run continuously. Because updates may lead to safety errors and security breaches, the question of their correctness is raised. Formal methods are a rigorous means to ensure the correctness required by applications using DSU. In this paper, we present a formal verification of correctness of DSU in a Java-based embedded system. Our approach is based on three major contributions. First, a formal interpretation of the semantic of update operations to ensure type safety of the update. Secondly, we rely on a functional representation of bytecode, the predicate transformation calculus and a functional model of the update mechanism to ensure the behavioural correctness of the updated programs. It is based on the use of Hoare predicate transformation to derive a specification of an updated bytecode. Thirdly, we use the functional representation to model the safe update point detection
A formal verification of safe update point detection in dynamic software updating
(Springer, 2017) Lounas, Razika; Jafri, Nisrine; Legay, Axel; Mezghiche, Mohamed; Lanet, Jean-Louis
Formalisation de la logique de description ALC dans l'assistant de preuve Coq
(2009) Chaabani, Mohamed; Mezghiche, Mohamed; Strecker, Martin
Le langage d’ontologie Web (Web Ontology Language OWL) est un langage utilis ́e pour le web s ́emantique. OWL est bas ́e sur les logiques de description (LD), une famille de lan- gages adapt ́es pour la repr ́esentation et le raisonnement sur des connaissances d’un domaine d’application d’une fa ̧con structur ́ee et formelle. Le web s ́emantique est actuellement l’un des champs d’application des m ́ethodes formelles, dont l’objectif est d’assurer leur fiabilit ́e. Un point essentiel de l’application de ces m ́ethodes formelles est la preuve de va- lidit ́e des raisonnements dans des LDs, comme celle de la terminaison, l’ad ́equation (soundness) et la compl ́etude d’un raisonneur. Dans ce papier, on pr ́esente une sp ́ecification formelle de la syntaxe et de la s ́emantique de ALC, qui est consid ́er ́ee comme un repr ́esentant typique d’une large gamme de LDs. On prouve pour cette logique les pro- pri ́et ́es d’ad ́equation, de compl ́etude et de terminaison dans l’assistant de preuve Coq.
A Formalized procedure for database horizontal fragmentation in isabelle/HOL Proof Assistant
(Springer, 2018) Cheikh, Salmi; Chaabani, Mohamed; Mezghiche, Mohamed
We propose a logical procedure for the horizontal fragmentation problem based on predicate abstraction over the entire domain of database relations. The set of minterm predicates is constructed using rewriting rules similar to the well-known semantic tableau algorithm. The procedure start from an initial set of simple predicates, build the set of minterm predicates until rules are no longer required. To ensure this proposition, we give a formal proof of its correctness namely, it’s soundness, completeness and termination with Isabelle proof assistant. The main contribution of this work are: refining the minterm approach by adding a semantic layer to predicates, minimizing the set of minterm predicates by automatically eliminating contradictory ones, detecting and handling subsumptions between them. This leads to the best construction time of the final partitioning schema. Finally, a source code of the procedure is generated automatically by the Isabelle proof assistant.