Single-Focus Broadening Navigation in Concept Lattices

Formal concept analysis has been used to support information retrieval tasks in many domains, in particular the traditional "by keyword" document search with a conjunctive query interpretation. However, support for exploratory search or browsing needs new navigation algorithms that allow users (i) to continuously update the current query and (ii) to broaden as well as refine the result set. In this paper we investigate a step-wise navigation algorithm that supports both broadening and refinement operations. Our navigation operations maintain some useful algebraic properties. We motivate our approach on a dataset of wine reviews, which contains different facets of information

Precise specification matching for adaptive reuse in embedded systems

AbstractSpecification matching is a key to reuse of components in embedded systems. Existing specification matching techniques for embedded systems are designed to match reactive behaviors using adaptive techniques to dynamically alter behaviors. However, correct specification matching demands both behavioral matching (that checks component adaptability) and functional matching (that ensures that proper functionality is reused). While approaches for behavioral matching exist, combined functional and behavioral matching during component reuse in embedded systems is lacking. This paper presents a precise specification matching, including both behavioral and functional matching. We introduce attributed labeled transition systems (ALTS) to formally specify component behavior and functionalities. Given ALTS of a new specification (a function F) and an existing component (a device D), a new refinement relation from F to D, called an S-matching relation, is proposed for precise specification matching. The existence of an S-matching relation is also shown to be a necessary and sufficient condition for the existence of a correct adapter to adapt D to match F both behaviorally and functionally. Automated component adaptation is facilitated by a matching tool implemented in a tabled logic programming environment, which provides distinct advantages for rapid implementation. Practical examples are given to illustrate how the concrete adapter is derived automatically from specification matching

Un environnement de spécification et de découverte pour la réutilisation des composants logiciels dans le développement des logiciels distribués

Notre travail vise à élaborer une solution efficace pour la découverte et la réutilisation des composants logiciels dans les environnements de développement existants et couramment utilisés. Nous proposons une ontologie pour décrire et découvrir des composants logiciels élémentaires. La description couvre à la fois les propriétés fonctionnelles et les propriétés non fonctionnelles des composants logiciels exprimées comme des paramètres de QoS. Notre processus de recherche est basé sur la fonction qui calcule la distance sémantique entre la signature d'un composant et la signature d'une requête donnée, réalisant ainsi une comparaison judicieuse. Nous employons également la notion de " subsumption " pour comparer l'entrée-sortie de la requête et des composants. Après sélection des composants adéquats, les propriétés non fonctionnelles sont employées comme un facteur distinctif pour raffiner le résultat de publication des composants résultats. Nous proposons une approche de découverte des composants composite si aucun composant élémentaire n'est trouvé, cette approche basée sur l'ontologie commune. Pour intégrer le composant résultat dans le projet en cours de développement, nous avons développé l'ontologie d'intégration et les deux services " input/output convertor " et " output Matching ".Our work aims to develop an effective solution for the discovery and the reuse of software components in existing and commonly used development environments. We propose an ontology for describing and discovering atomic software components. The description covers both the functional and non functional properties which are expressed as QoS parameters. Our search process is based on the function that calculates the semantic distance between the component interface signature and the signature of a given query, thus achieving an appropriate comparison. We also use the notion of "subsumption" to compare the input/output of the query and the components input/output. After selecting the appropriate components, the non-functional properties are used to refine the search result. We propose an approach for discovering composite components if any atomic component is found, this approach based on the shared ontology. To integrate the component results in the project under development, we developed the ontology integration and two services " input/output convertor " and " output Matching "

Structuring Teachable Knowledge through Program-Concept Classifications

Teaching CS is a challenging task, especially for those without prior programming experience. Even for veteran educators, having to learn CS concepts while also trying to teach those same concepts is difficult; as is the case for many K-12 CS instructors. Unfortunately, there is often no formalized order with CS concepts, as they are complex and can be interrelated in many ways through many programs. Numerous resources exist to try to address this problem, but they are often inconsistent and subjective. To address this problem of presentation order, this thesis contributes a technique for structuring teachable concepts through lattices of program-concept classifications. This technique identifies and relates concepts with the abstract syntax of programs and produces classifications that group sets of programs with sets of related concepts. The resulting set of classifications has a partial ordering and allows defining methods for exploring knowledge of concepts through a complete lattice. The basis of this technique is derived from the theory of Formal Concept Analysis (FCA), which allows reasoning about collections of objects and their attributes. A Haskell implementation of this technique is introduced, along with the description of a web application that allows interactive exploring of programs and concepts. A brief exploratory case study on the efficacy of this web application is also relayed. This thesis then concludes that program-concept classifications are an effective way to structure the progression of CS concepts through language syntax, but this approach requires careful consideration of the programs used to generate classifications

Un compilateur de traitement du paquet pour les réseaux multi-tenants

Le Software Defined Network (SDN) est un nouveau paradigme de design et de gestion des réseaux. Le SDN se base sur la séparation entre le plan de données et le plan de contrôle. Le réseau est géré à travers un contrôleur centralisé. Ce dernier gère la politique d'acheminement et d'aiguillage des paquets sur tout le réseau par des opérations d'ajout et de suppression des règles. Le SDN simplifie la virtualisation réseau où plusieurs tenants peuvent coexister sur la même infrastructure physique, chaque tenant a son propre contrôleur qui dicte la politique de traitement des paquets dans son réseau. Cela pose des problèmes au niveau du partage des ressources et d'isolation du trafic. Pour assurer une isolation du trafic entre les différents tenants ainsi qu'une haute performance d'acheminement du paquet sur tout le réseau, on introduit un compilateur centrale qui fera la translation, la distribution et l'application des règles sur l'infrastructure physique. Dans ce rapport, nous allons détailler la conception d'un compilateur de règles pour un réseau multi-tenants. Ce compilateur transforme les règles et adapte les structures de classification pour tenir compte des contraintes matérielles des équipements. Une implémentation du compilateur a été développée pour les switches physiques et logiciels. Les tests ont montré une réduction de 20% à 30% de nombre des entrées, une capacité de mise à jour qui s'élève à 300 règles/seconde et une minimisation du délai du traitement des paquets par 2-3 us et par 50-100 us respectivement pour les switches physiques et logiciels

Semantic Component Selection Based on Non-Functional Requirements

Reusing existing software components in place of requiring the implementation of new components can reduce the complexity of the software development process. However, for a software component to be effectively identified and selected for reuse, we need a good understanding of both the functional and non-functional requirements of the component needed, and the components available. Functional requirements specify what a software component does and non-functional requirements specify how a software component achieves its goals. Non-functional requirements are typically complex, and difficult to both understand and effectively articulate. Requirements engineering provides a solution to easing this process, and involves performing the following reasoning steps: elicitation, analysis and description. However, the output of these steps is based on reasoning that requires manual, expensive and error-prone techniques. To solve such drawbacks, this thesis describes a framework that provides the necessary tools and techniques for automating reasoning including: an ontology for non-functional requirements as a conceptual model for reasoning; and a search algorithm that matches the best component according to the reasoning process outputs. To validate our framework, we develop an implementation that supports semantic search within a repository to locate matches based on a user query, validated with experimental findings on a repository consisting of 50 individual component descriptions. Our findings demonstrate the benefit obtained from using an ontology, by minimizing the cost and complexity of analysing non-functional requirements. Our algorithm is capable of running a complex query, for example, supporting 5 non-functional requirements with total 16 prerequisites against a repository of 1000 components can run in 1750 second. It would be impossible for a field expert to compute a complex query in this time frame.Thesis (MCompSc) -- University of Adelaide, School of Computer Science, 201

From Domain Models to Components - A Formal Transformation Approach Towards Dependable Software Development

Many academic, industrial, and government research units have unanimously acknowledged the importance of developing dependable software systems. At the same time they have also concurred on the difficulties and challenges to be surmounted in achieving the goal. The importance of domain analysis and linking domain models to software artifacts were also recognized by various researchers. However, no formal approach to domain analysis was attempted. The primary motivation for this thesis stems from this context. Component-based software engineering offers some attractive mechanisms to tackle the inherent complexity in developing dependable systems. Recently a formal approach has been put forth for such a development. This thesis provides a formal approach for domain analysis, and transforms the domain model to components desired by this development process. Formal Concept Analysis (FCA) is a mathematical theory for identifying and classifying concepts. This thesis taps its potential to formally analyze the domain in a software development context. It turns out that the approach presented in this thesis cannot be fully automated; nevertheless several useful contributions have been made. These include (1) capturing formal concepts and defining them in FCA; (2) defining composition rules to categorize formal concepts and their trustworthy properties; (3) integrating partial formal context tables to build the concept lattice; (4) specifying and developing a model transformation approach to construct trustworthy OWL ontology; (5) implementing a model transformation technique to generate the TADL specification of the reusable component-based system. The proposed approach is applied to CoCoME, as a benchmark case study in the domain of component-based development

Exploiting the architectural characteristics of software components to improve software reuse

PhD ThesisSoftware development is a costly process for all but the most trivial systems. One of the commonly known ways of minimizing development costs is to re-use previously built software components. However, a significant problem that source-code re-users encounter is the difficulty of finding components that not only provide the functionality they need but also conform to the architecture of the system they are building. To facilitate finding reusable components there is a need to establish an appropriate mechanism for matching the key architectural characteristics of the available source-code components against the characteristics of the system being built. This research develops a precise characterization of the architectural characteristics of source-code components, and investigates a new way to describe how appropriate components for re-use can be identified and categorized.Umm Al- Qura University