b Pour un « Front économique » vraiment libéral ! By www.lepoint.fr Published On :: Wed, 13 Nov 2024 12:00:00 +0100 TRIBUNE. Des experts saluent la creation de ce collectif pro-business, tout en exprimant le souhait qu'il s'attaque egalement au dirigisme de l'Etat. Full Article
b Guillaume Kasbarian félicite Elon Musk tout juste nommé ministre par Trump, la gauche s’insurge By www.lepoint.fr Published On :: Wed, 13 Nov 2024 12:25:00 +0100 Apres la nomination d'Elon Musk a la tete d'un ministere de l'Efficacite gouvernementale, le ministre de la Fonction publique francais a exprime sa << hate >> de << partager les meilleures pratiques >>. Full Article
b La détention de Paul Watson prolongée jusqu’en décembre By www.lepoint.fr Published On :: Wed, 13 Nov 2024 14:23:00 +0100 Le patron de l'ONG de defense des oceans Sea Shepherd avait fait une demande d'asile politique a Emmanuel Macron, au mois d'octobre. Full Article
b Omar Youssef Souleimane : « Ce que j’ai entendu dans des classes de banlieue » By www.lepoint.fr Published On :: Wed, 13 Nov 2024 09:00:00 +0100 L'ecrivain d'origine syrienne a anime dans des colleges franciliens des ateliers organises pour lutter contre la radicalisation et promouvoir la laicite. Il temoigne. Full Article
b Thibault de Montaigu, lauréat du prix Interallié pour « Cœur » By www.lepoint.fr Published On :: Wed, 13 Nov 2024 13:04:00 +0100 Un arriere-grand-pere heroique, un pere fantasque... Avec << Coeur >>, l'ecrivain raconte le destin flamboyant de ses aieux dans un livre aussi intime que romanesque et recompense par le jury de l'Interallie. Full Article
b Sondage : Barnier au coude-à-coude avec Le Pen By www.lepoint.fr Published On :: Wed, 13 Nov 2024 07:30:00 +0100 La nouvelle enquete Cluster17 pour << Le Point >> installe le Premier ministre dans le top 5 des personnalites politiques preferees des Francais. Gabriel Attal et Gerald Darmanin chutent. Full Article
b Marine Le Pen dans le piège de « l’inéligibilité obligatoire » By www.lepoint.fr Published On :: Wed, 13 Nov 2024 08:00:00 +0100 Alors que les procureurs doivent requerir, ce mercredi 13 novembre a son proces, la presidente du groupe RN a l'Assemblee redoute, par-dessus tout, d'etre empechee de se presenter en 2027. Full Article
b Teresa Ribera fait tanguer la Commission von der Leyen By www.lepoint.fr Published On :: Wed, 13 Nov 2024 12:41:00 +0100 << Incompetence >>, << radicalisme environnemental >>... L'Espagnole, proposee au poste de vice-presidente de la Commission en charge de la Transition ecologique, est bousculee par les deputes europeens. Full Article
b « Gladiator II » : bis repetita, triste cirque By www.lepoint.fr Published On :: Wed, 13 Nov 2024 13:14:00 +0100 L'infatigable Ridley Scott se repose pourtant sur ses lauriers avec cette suite inutile et empatee de son propre classique sorti en 2000. Spectaculaire mais vain. Full Article
b Cotentin : un nouveau canot de sauvetage en mer bloqué à quai par la réglementation By www.lepoint.fr Published On :: Wed, 13 Nov 2024 06:25:00 +0100 La station de sauvetage de Goury-La Hague a recu un nouveau canot ultramoderne. Mais il est bloque a quai, car trop polluant, selon les regles environnementales internationales. Full Article
b La présidente du Conseil national des barreaux répond aux critiques By www.lepoint.fr Published On :: Wed, 13 Nov 2024 12:17:00 +0100 INTERVIEW. << J'aurais souhaite une contribution plus prospective et moins desobligeante a l'egard des barreaux de province >>, reagit M e Julie Couturier au rapport du P r Jamin. Full Article
b Jean-Marie Le Pen hospitalisé à la suite d’un état de faiblesse général By www.lepoint.fr Published On :: Wed, 13 Nov 2024 14:47:00 +0100 Le fondateur du Front national, age de 96 ans et qui a mis un terme a sa vie politique, est hospitalise afin de passer plusieurs examens, par << souci de securite >>. Full Article
b Enciende tu voz: el desafío de escribir tu primer libro By blog.lengua-e.com Published On :: Tue, 16 Apr 2024 09:24:00 +0000 Este artículo es para ti si quieres embarcarte en una travesía única: la aventura de escribir tu primer libro. No estoy hablando de un libro […] Origen Full Article creación escritura crear escribir primer libro
b Becas de grado Jesús Serra 2024 de Fundación Occident By blog.lengua-e.com Published On :: Tue, 30 Apr 2024 14:36:37 +0000 Hoy comparto contigo información sobre una iniciativa de Fundación Occident: las becas de grado Jesús Serra, que se convocan por primera vez en 2024. Además […] Origen Full Article otros becas Becas de grado Jesús Serra estudios estudios universitarios Fundación Occident universidad
b ¿Por dónde empiezo? Escribir un libro sin haber estudiado literatura By blog.lengua-e.com Published On :: Mon, 08 Jul 2024 14:43:00 +0000 Publico este artículo para contestar a un comentario que he recibido y que me ha hecho reflexionar. El comentario de esta persona toca varios puntos […] Origen Full Article creación escritura literatura cómo escribir un libro escribir escribir un libro escritor estudios
b Clásicos que cambian vidas By blog.lengua-e.com Published On :: Mon, 22 Jul 2024 10:01:27 +0000 Los clásicos acumulan el saber y la emoción de las mentes más brillantes de la historia, de los corazones que han latido con más pasión. […] Origen Full Article literatura clásicos experiencias lecturas libros
b El contenido es el rey: cómo escribir un libro By blog.lengua-e.com Published On :: Mon, 02 Sep 2024 14:01:26 +0000 ¿Te gustaría escribir un libro? ¿Alguna vez lo has intentado? Sé que escribir un libro puede parecer un reto formidable. Muchas personas se preguntan si […] Origen Full Article creación escritura contenido escribir escribir un libro escritores
b Para qué escribir un libro By blog.lengua-e.com Published On :: Mon, 07 Oct 2024 10:43:07 +0000 Uno de mis alumnos está escribiendo ahora las memorias de su infancia. Es un libro hermoso, sincero, único, en el que rescata los recuerdos luminosos […] Origen Full Article creación escritura libro escribir escribir un libro motivos
b Lo más importante para escribir By blog.lengua-e.com Published On :: Mon, 28 Oct 2024 16:54:56 +0000 Mi vocación es ayudar a escribir mejor a personas como tú. Llevo muchos años en esta maravillosa tarea y constato que la gente tiende a […] Origen Full Article creación escritura escribir escritor herramientas ideas libro técnica
b Integrating Personal Web Data through Semantically Enhanced Web Portal By www.jucs.org Published On :: 2011-03-18T16:21:08+01:00 Currently, the World Wide Web is mostly composed of isolated and loosely connected "data islands". Connecting them together and retrieving only the information that is of interest to the user is the common Web usage process. Creating infrastructure that would support automation of that process by aggregating and integrating Web data in accordance to user's personal preferences would greatly improve today's Web usage. A significant part of Web data is available only through the login and password protected applications. As that data is very important for the usefulness of described process, proposed infrastructure needs to support authorized access to user's personal data. In this paper we propose a semantically enhanced Web portal that presents unique personalized user's entry to the domain-specific Web information. We also propose an identity management system that supports authorized access to the protected Web data. To verify the proposed solution, we have built Sweb - a semantically enhanced Web portal that uses proposed identity management system. Full Article
b Impact of CPU-bound Processes on IP Forwarding of Linux and Windows XP By www.jucs.org Published On :: 2011-03-18T16:21:13+01:00 These days, commodity-off-the-shelf (COTS) hardware and software are used to build high-end and powerful workstations and servers to be deployed in today's local area networks of private homes and small- to medium-sized business. Typically, these servers are multipurpose and shared - running networking functionalities involving IP packet forwarding in addition to other CPU intensive applications. In this paper we study and investigate the impact of running CPU-bound applications on the performance of IP packet forwarding. We measure and compare the impact and performance for the two operating systems of choice for home and small-business users, namely Linux and Windows XP. The performance is studied in terms of key performance metrics which include throughput, packet loss, round-trip delay, and CPU availability. For our measurements, we consider today's typical home network hosts of modern processors and Gigabit network cards. We also consider different configuration setups and utilize open-source tools to generate relatively high traffic rates. Our empirical results show that Linux exhibits superior performance over Windows XP in terms of IP forwarding performance. Results also show that, unlike Windows XP, the IP forwarding performance of Linux is not significantly impacted by running CPU-bound applications. Full Article
b Information Consolidation in Large Bodies of Information By www.jucs.org Published On :: 2011-03-18T16:21:18+01:00 Due to information technologies the problem we are facing today is not a lack of information but too much information. This phenomenon becomes very clear when we consider two figures that are often quoted: Knowledge is doubling in many fields (biology, medicine, computer science, ...) within some 6 years; yet information is doubling every 8 months! This implies that the same piece of information/knowledge is published a large number of times with small variations. Just look at an arbitrary news item. If considered of some general interest reports of it will appear in all major newspapers, journals, electronic media, etc. This is also the problem with information portals that tie together a number of large databases. It is our contention that we need methods to reduce the huge set of information concerning a particular topic to a number of pieces of information (let us call each such piece an "essay" in what follows) that present a good cross-section of potential points of view. We will explain why one essay is usually not enough, yet the problem of reducing a huge amount of contributions to a digestible number of essays is formidable, indeed is science fiction at the moment. We will argue in this paper that it is one of the important tasks of computer sciences to start tackling this problem, and we will show that in some special cases partial solutions are possible. Full Article
b Nabuco - Two Decades of Document Processing in Latin America By www.jucs.org Published On :: 2011-04-07T14:39:03+02:00 This paper reports on the Joaquim Nabuco Project, a pioneering work in Latin America on document digitalization, enhancement, compression, indexing, retrieval and network transmission of historical document images. Full Article
b Developing a Mobile Collaborative Tool for Business Continuity Management By www.jucs.org Published On :: 2011-07-08T12:29:58+02:00 We describe the design of a mobile collaborative tool that helps teams managing critical computing infrastructures in organizations, a task that is usually designated Business Continuity Management. The design process started with a requirements definition phase based on interviews with professional teams. The elicited requirements highlight four main concerns: collaboration support, knowledge management, team performance, and situation awareness. Based on these concerns, we developed a data model and tool supporting the collaborative update of Situation Matrixes. The matrixes aim to provide an integrated view of the operational and contextual conditions that frame critical events and inform the operators' responses to events. The paper provides results from our preliminary experiments with Situation Matrixes. Full Article
b The Iceberg Effect: Behind the User Interface of Mobile Collaborative Systems By www.jucs.org Published On :: 2011-07-08T12:29:59+02:00 Advances in mobile technologies are opening new possibilities to support collaborative activities through mobile devices. Unfortunately, mobile collaborative systems have been difficult to conceive, design and implement. These difficulties are caused in part by their unclear requirements and developers' lack of experience with this type of systems. However, several requirements involved in the collaborative back-end of these products are recurrent and should be considered in every development. This paper introduces a characterization of mobile collaboration and a framework that specifies a list of general requirements to be considered during the conception and design of a system in order to increase its probability of success. This framework was used in the development of two mobile collaborative systems, providing developers with a base of back-end requirements to aid system design and implementation. The systems were positively evaluated by their users. Full Article
b An Empirical Study on Human and Information Technology Aspects in Collaborative Enterprise Networks By www.jucs.org Published On :: 2011-07-08T12:30:00+02:00 Small and Medium Enterprises (SMEs) face new challenges in the global market as customers require more complete and flexible solutions and continue to drastically reduce the number of suppliers. SMEs are trying to address these challenges through cooperation within collaborative enterprise networks (CENs). Human aspects constitute a fundamental issue in these networks as people, as opposed to organizations or Information Technology (IT) systems, cooperate. Since there is a lack of empirical studies on the role of human factors in IT-supported collaborative enterprise networks, this paper addresses the major human aspects encountered in this type of organization. These human aspects include trust issues, knowledge and know-how sharing, coordination and planning activities, and communication and mutual understanding, as well as their influence on the business processes of CENs supported by IT tools. This paper empirically proves that these aspects constitute key factors for the success or the failure of CENs. Two case studies performed on two different CENs in Switzerland are presented and the roles of human factors are identified with respect to the IT support systems. Results show that specific human factors, namely trust and communication and mutual understanding have to be well addressed in order to design and develop adequate software solutions for CENs. Full Article
b Managing Mechanisms for Collaborative New-Product Development in the Ceramic Tile Design Chain By www.jucs.org Published On :: 2011-07-08T12:30:02+02:00 This paper focuses on improving the management of New-Product Development (NPD) processes within the particular context of a cluster of enterprises that cooperate through a network of intra- and inter-firm relations. Ceramic tile design chains have certain singularities that condition the NPD process, such as the lack of a strong hierarchy, fashion pressure or the existence of different origins for NPD projects. We have studied these particular circumstances in order to tailor Product Life-cycle Management (PLM) tools and some other management mechanisms to fit suitable sectoral reference models. Special emphasis will be placed on PLM templates for structuring and standardizing projects, and also on the roles involved in the process. Full Article
b A Petri Nets based Approach to Specify Individual and Collaborative Interaction in 3D Virtual Environments By www.jucs.org Published On :: 2011-07-08T12:30:03+02:00 This work describes a methodology that supports the design and implementation of software modules, which represent the individual and collaborative three-dimensional interaction process phases. The presented methodology integrates three modeling approaches: Petri Nets, a collaborative manipulation model based on the combination of single user interaction techniques taxonomy, and object-oriented programming concepts. The combination of these elements allows for the description of interaction tasks, the sequence of interaction processes being controlled by Petri Nets with the codes generated automatically. By the integration of these approaches, the present work addresses not only the entire development cycle of both individual and collaborative three-dimensional interaction, but also the reuse of developed interaction blocks in new virtual environment projects. Full Article
b Let Me Tell You a Story - On How to Build Process Models By www.jucs.org Published On :: 2011-07-08T12:30:05+02:00 Process Modeling has been a very active research topic for the last decades. One of its main issues is the externalization of knowledge and its acquisition for further use, as this remains deeply related to the quality of the resulting process models produced by this task. This paper presents a method and a graphical supporting tool for process elicitation and modeling, combining the Group Storytelling technique with the advances of Text Mining and Natural Language Processing. The implemented tool extends its previous versions with several functionalities to facilitate group story telling by the users, as well as to improve the results of the acquired process model from the stories. Full Article
b Security and Privacy Preservation for Mobile E-Learning via Digital Identity Attributes By www.jucs.org Published On :: 2011-07-08T12:30:07+02:00 This paper systematically discusses the security and privacy concerns for e-learning systems. A five-layer architecture of e-learning system is proposed. The security and privacy concerns are addressed respectively for five layers. This paper further examines the relationship among the security and privacy policy, the available security and privacy technology, and the degree of e-learning privacy and security. The digital identity attributes are introduced to e-learning portable devices to enhance the security and privacy of e-learning systems. This will provide significant contributions to the knowledge of e-learning security and privacy research communities and will generate more research interests. Full Article
b Realising the Potential of Web 2.0 for Collaborative Learning Using Affordances By www.jucs.org Published On :: 2011-07-08T12:30:08+02:00 With the emergence of the Web 2.0 phenomena, technology-assisted social networking has become the norm. The potential of social software for collaborative learning purposes is clear, but as yet there is little evidence of realisation of the benefits. In this paper we consider Information and Communication Technology student attitudes to collaboration and via two case studies the extent to which they exploit the use of wikis for group collaboration. Even when directed to use a particular wiki designed for the type of project they are involved with, we found that groups utilized the wiki in different ways according to the affordances ascribed to the wiki. We propose that the integration of activity theory with an affordances perspective may lead to improved technology, specifically Web 2.0, assisted collaboration. Full Article
b Enhancement of Collaborative Learning Activities using Portable Devices in the Classroom By www.jucs.org Published On :: 2011-07-08T12:30:09+02:00 Computer Supported Collaborative Learning could highly impact education around the world if the proper Collaborative Learning tools are set in place. In this paper we describe the design of a collaborative learning activity for teaching Chemistry to Chilean students. We describe a PDA-based software tool that allows teachers to create workgroups in their classrooms in order to work on the activity. The developed software tool has three modules: one module for teachers, which runs on a PC and lets them create the required pedagogical material; second, there is a PDA module for students which lets them execute the activity; finally, a third module allows the teacher set workgroups and monitor each workgroup during the activity. Full Article
b The Architectural Design of a System for Interpreting Multilingual Web Documents in E-speranto By www.jucs.org Published On :: 2011-04-24T11:14:58+02:00 E-speranto is a formal language for generating multilingual texts on the World Wide Web. It is currently still under development. The vocabulary and grammar rules of E-speranto are based on Esperanto; the syntax of E-speranto, however, is based on XML (eXtensible Markup Language). The latter enables the integration of documents generated in E-speranto into web pages. When a user accesses a web page generated in E-speranto, the interpreter interprets the document into a chosen natural language, which enables the user to read the document in any arbitrary language supported by the interpreter. The basic parts of the E-speranto interpreting system are the interpreters and information resources, which complies with the principle of separating the interpretation process from the data itself. The architecture of the E-speranto interpreter takes advantage of the resemblance between the languages belonging to the same linguistic group, which consequently results in a lower production cost of the interpreters for the same linguistic group. We designed a proof-of-concept implementation for interpreting E-speranto in three Slavic languages: Slovenian, Serbian and Russian. These languages share many common features in addition to having a similar syntax and vocabulary. The content of the information resources (vocabulary, lexicon) was limited to the extent that was needed to interpret the test documents. The testing confirmed the applicability of our concept and also indicated the guidelines for future development of both the interpreters and E-speranto itself. Full Article
b On Compound Purposes and Compound Reasons for Enabling Privacy By www.jucs.org Published On :: 2011-04-24T11:15:18+02:00 This paper puts forward a verification method for compound purposes and compound reasons to be used during purpose limitation. When it is absolutely necessary to collect privacy related information, it is essential that privacy enhancing technologies (PETs) protect access to data - in general accomplished by using the concept of purposes bound to data. Compound purposes and reasons are an enhancement of purposes used during purpose limitation and binding and are more expressive than purposes in their general form. Data users specify their access needs by making use of compound reasons which are defined in terms of (compound) purposes. Purposes are organised in a lattice with purposes near the greatest lower bound (GLB) considered weak (less specific) and purposes near the least upper bound (LUB) considered strong (most specific). Access is granted based on the verification of the statement of intent (from the data user) against the compound purpose bound to the data; however, because purposes are in a lattice, the data user is not limited to a statement of intent that matches the purposes bound to the data exactly - the statement can be a true reflection of their intent with the data. Hence, the verification of compound reasons against compound purposes cannot be accomplished by current published verification algorithms. Before presenting the verification method, compound purposes and reasons, as well as the structures used to represent them, and the operators that are used to define compounds is presented. Finally, some thoughts on implementation are provided. Full Article
b Rule of Law on the Go: New Developments of Mobile Governance By www.jucs.org Published On :: 2011-04-24T11:15:48+02:00 This paper offers an overview of the emerging domain of mobile governance as an offspring of the broader landscape of e-governance. Mobile governance initiatives have been deployed everywhere in parallel to the development of crowdsourced, open source software applications that facilitate the collection, aggregation, and dissemination of both information and data coming from different sources: citizens, organizations, public bodies, etc. Ultimately, mobile governance can be seen as a tool to promote the rule of law from a decentralized, distributed, and bottom-up perspective. Full Article
b IDEA: A Framework for a Knowledge-based Enterprise 2.0 By www.jucs.org Published On :: 2011-07-08T12:31:41+02:00 This paper looks at the convergence of knowledge management and Enterprise 2.0 and describes the possibilities for an over-arching exchange and transfer of knowledge in Enterprise 2.0. This will be underlined by the presentation of the concrete example of T-System Multimedia Solutions (MMS), which describes the establishment of a new enterprise division "IG eHealth". This is typified by the decentralised development of common ideas, collaboration and the assistance available to performing responsibilities as provided by Enterprise 2.0 tools. Taking this archetypal example and the derived abstraction of the problem regarding the collaboration of knowledge workers as the basis, a regulatory framework will be developed for knowledge management to serve as a template for the systemisation and definition of specific Enterprise 2.0 activities. The paper will conclude by stating factors of success and supporting Enterprise 2.0 activities, which will facilitate the establishment of a practical knowledge management system for the optimisation of knowledge transfer. Full Article
b Enterprise Microblogging for Advanced Knowledge Sharing: The References@BT Case Study By www.jucs.org Published On :: 2011-07-08T12:31:42+02:00 Siemens is well known for ambitious efforts in knowledge management, providing a series of innovative tools and applications within the intranet. References@BT is such a web-based application with currently more than 7,300 registered users from more than 70 countries. Its goal is to support the sharing of knowledge, experiences and best-practices globally within the Building Technologies division. Launched in 2005, References@BT features structured knowledge references, discussion forums, and a basic social networking service. In response to use demand, a new microblogging service, tightly integrated into References@BT, was implemented in March 2009. More than 500 authors have created around 2,600 microblog postings since then. Following a brief introduction into the community platform References@BT, we comprehensively describe the motivation, experiences and advantages for an organization in providing internal microblogging services. We provide detailed microblog usage statistics, analyzing the top ten users regarding postings and followers as well as the top ten topics. In doing so, we aim to shed light on microblogging usage and adoption within a globally distributed organization. Full Article
b Leveraging Web 2.0 in New Product Development: Lessons Learned from a Cross-company Study By www.jucs.org Published On :: 2011-07-08T12:31:43+02:00 The paper explores the application of Web 2.0 technologies to support product development efforts in a global, virtual and cross-functional setting. It analyses the dichotomy between the prevailing hierarchical structure of CAD/PLM/PDM systems and the principles of the Social Web under the light of the emerging product development trends. Further it introduces the concept of Engineering 2.0, intended as a more bottom up and lightweight knowledge sharing approach to support early stage design decisions within virtual and cross-functional product development teams. The lessons learned collected from a cross-company study highlight how to further developblogs, wikis, forums and tags for the benefit of new product development teams, highlighting opportunities, challenges and no-go areas. Full Article
b On the Construction of Efficiently Navigable Tag Clouds Using Knowledge from Structured Web Content By www.jucs.org Published On :: 2011-07-08T12:31:45+02:00 In this paper we present an approach to improving navigability of a hierarchically structured Web content. The approach is based on an integration of a tagging module and adoption of tag clouds as a navigational aid for such content. The main idea of this approach is to apply tagging for the purpose of a better highlighting of cross-references between information items across the hierarchy. Although in principle tag clouds have the potential to support efficient navigation in tagging systems, recent research identified a number of limitations. In particular, applying tag clouds within pragmatic limits of a typical user interface leads to poor navigational performance as tag clouds are vulnerable to a so-called pagination effect. In this paper, a solution to the pagination problem is discussed, implemented as a part of an Austrian online encyclopedia called Austria-Forum, and analyzed. In addition, a simulation-based evaluation of the new algorithm has been conducted. The first evaluation results are quite promising, as the efficient navigational properties are restored. Full Article
b A Clustering Approach for Collaborative Filtering Recommendation Using Social Network Analysis By www.jucs.org Published On :: 2011-07-08T12:31:46+02:00 Collaborative Filtering(CF) is a well-known technique in recommender systems. CF exploits relationships between users and recommends items to the active user according to the ratings of his/her neighbors. CF suffers from the data sparsity problem, where users only rate a small set of items. That makes the computation of similarity between users imprecise and consequently reduces the accuracy of CF algorithms. In this article, we propose a clustering approach based on the social information of users to derive the recommendations. We study the application of this approach in two application scenarios: academic venue recommendation based on collaboration information and trust-based recommendation. Using the data from DBLP digital library and Epinion, the evaluation shows that our clustering technique based CF performs better than traditional CF algorithms. Full Article
b ODR, Ontologies, and Web 2.0 By www.jucs.org Published On :: 2011-07-08T12:31:49+02:00 Online communities and institutions create new spaces for interaction, but also open new avenues for the emergence of grievances, claims, and disputes. Consequently, online dispute resolution (ODR) procedures are core to these new online worlds. But can ODR mechanisms provide sufficient levels of reputation, trust, and enforceability for it to become mainstream? This contribution introduces the new approaches to ODR and provides a description of the design and structure of Ontomedia, a web-based platform to facilitate online mediation in different domains. Full Article
b Web 2.0: Applications and Mechanisms By www.jucs.org Published On :: 2011-07-08T12:31:50+02:00 Full Article
b Modeling Quality Attributes with Aspect-Oriented Architectural Templates By www.jucs.org Published On :: 2011-05-06T16:03:16+02:00 The quality attributes of a software system are, to a large extent, determined by the decisions taken early in the development process. Best practices in software engineering recommend the identification of important quality attributes during the requirements elicitation process, and the specification of software architectures to satisfy these requirements. Over the years the software engineering community has studied the relationship between quality attributes and the use of particular architectural styles and patterns. In this paper we study the relationship between quality attributes and Aspect-Oriented Software Architectures - which apply the principles of Aspect-Oriented Software Development (AOSD) at the architectural level. AOSD focuses on identifying, modeling and composing crosscutting concerns - i.e. concerns that are tangled and/or scattered with other concerns of the application. In this paper we propose to use AO-ADL, an aspect-oriented architectural description language, to specify quality attributes by means of parameterizable, and thus reusable, architectural patterns. We particularly focus on quality attributes that: (1) have major implications on software functionality, requiring the incorporation of explicit functionality at the architectural level; (2) are complex enough as to be modeled by a set of related concerns and the compositions among them, and (3) crosscut domain specific functionality and are related to more than one component in the architecture. We illustrate our approach for usability, a critical quality attribute that satisfies the previous constraints and that requires special attention at the requirements and the architecture design stages. Full Article
b Bio-Inspired Mechanisms for Coordinating Multiple Instances of a Service Feature in Dynamic Software Product Lines By www.jucs.org Published On :: 2011-05-06T16:03:21+02:00 One of the challenges in Dynamic Software Product Line (DSPL) is how to support the coordination of multiple instances of a service feature. In particular, there is a need for a decentralized decision-making capability that will be able to seamlessly integrate new instances of a service feature without an omniscient central controller. Because of the need for decentralization, we are investigating principles from self-organization in biological organisms. As an initial proof of concept, we have applied three bio-inspired techniques to a simple smart home scenario: quorum sensing based service activation, a firefly algorithm for synchronization, and a gossiping (epidemic) protocol for information dissemination. In this paper, we first explain why we selected those techniques using a set of motivating scenarios of a smart home and then describe our experiences in adopting them. Full Article
b QoS-based Approach for Dynamic Web Service Composition By www.jucs.org Published On :: 2011-05-06T16:03:31+02:00 Web Services have become a standard for integration of systems in distributed environments. By using a set of open interoperability standards, they allow computer-computer interaction, regardless the programming languages and operating systems used. The Semantic Web Services, by its turn, make use of ontologies to describe their functionality in a more structural manner, allowing computers to reason about the information required and provided by them. Such a description also allows dynamic composition of several Web Services, when only one is not able to provide the desired functionality. There are scenarios, however, in which only the functional correctness is not enough to fulfill the user requirements, and a minimum level of quality should be guaranteed by their providers. In this context, this work presents an approach for dynamic Web Service composition that takes into account the composition overall quality. The proposed approach relies on a heuristics to efficiently perform the composition. In order to show the feasibility of the proposed approach, a Web Service composition application prototype was developed and experimented with public test sets, along with another approach that does not consider quality in the composition process. The results have shown that the proposed approach in general finds compositions with more quality, within a reasonable processing time. Full Article
b An Aspect-Oriented Framework for Weaving Domain-Specific Concerns into Component-Based Systems By www.jucs.org Published On :: 2011-05-06T16:03:36+02:00 Software components are used in various application domains, and many component models and frameworks have been proposed to fulfill domain-specific requirements. The general trend followed by these approaches is to provide ad-hoc models and tools for capturing these requirements and for implementing their support within dedicated runtime platforms, limited to features of the targeted domain. The challenge is then to propose more flexible solutions, where components reuse is domain agnostic. In this article, we present a framework supporting compositional construction and development of applications that must meet various extra-functional/domain-specific requirements. The key points of our contribution are: i) We target development of component-oriented applications where extra-functional requirements are expressed as annotations on the units of composition in the application architecture. ii) These annotations are implemented as open and extensible component-based containers, achieving full separation of functional and extra-functional concerns. iii) Finally, the full machinery is implemented using the Aspect-Oriented Programming paradigm. We validate our approach with two case studies: the first is related to real-time and embedded applications, while the Full Article
b Context-Aware Composition and Adaptation based on Model Transformation By www.jucs.org Published On :: 2011-05-06T16:03:43+02:00 Using pre-existing software components (COTS) to develop software systems requires the composition and adaptation of the component interfaces to solve mismatch problems. These mismatches may appear at different interoperability levels (signature, behavioural, quality of service and semantic). In this article, we define an approach which supports composition and adaptation of software components based on model transformation by taking into account the four levels. Signature and behavioural levels are addressed by means of transition systems. Context-awareness and semanticbased techniques are used to tackle quality of service and semantic, respectively, but also both consider the signature level. We have implemented and validated our proposal for the design and application of realistic and complex systems. Here, we illustrate the need to support the variability of the adaptation process in a context-aware pervasive system through a real-world case study, where software components are implemented using Windows Workflow Foundation (WF). We apply our model transformation process to extract transition systems (CA-STS specifications) from WF components. These CA-STSs are used to tackle the composition and adaptation. Then, we generate a CASTS adaptor specification, which is transformed into its corresponding WF adaptor component with the purpose of interacting with all the WF components of the system, thereby avoiding mismatch problems. Full Article
b A Framework to Evaluate Interface Suitability for a Given Scenario of Textual Information Retrieval By www.jucs.org Published On :: 2011-07-04T16:04:41+02:00 Visualization of search results is an essential step in the textual Information Retrieval (IR) process. Indeed, Information Retrieval Interfaces (IRIs) are used as a link between users and IR systems, a simple example being the ranked list proposed by common search engines. Due to the importance that takes visualization of search results, many interfaces have been proposed in the last decade (which can be textual, 2D or 3D IRIs). Two kinds of evaluation methods have been developed: (1) various evaluation methods of these interfaces were proposed aiming at validating ergonomic and cognitive aspects; (2) various evaluation methods were applied on information retrieval systems (IRS) aiming at measuring their effectiveness. However, as far as we know, these two kinds of evaluation methods are disjoint. Indeed, considering a given IRI associated to a given IRS, what happens if we associate this IRI to another IRS not having the same effectiveness. In this context, we propose an IRI evaluation framework aimed at evaluating the suitability of any IRI to different IR scenarios. First of all, we define the notion of IR scenario as a combination of features related to users, IR tasks and IR systems. We have implemented the framework through a specific evaluation platform that enables performing IRI evaluations and that helps end-users (e.g. IRS developers or IRI designers) in choosing the most suitable IRI for a specific IR scenario. Full Article
b Descriptional Complexity of Ambiguity in Symmetric Difference NFAs By www.jucs.org Published On :: 2011-07-04T16:04:44+02:00 We investigate ambiguity for symmetric difference nondeterministic finite automata. We show the existence of unambiguous, finitely ambiguous, polynomially ambiguous and exponentially ambiguous symmetric difference nondeterministic finite automata. We show that, for each of these classes, there is a family of n-state nondeterministic finite automata such that the smallest equivalent deterministic finite automata have O(2n) states. Full Article
b Improving Security Levels of IEEE802.16e Authentication by Involving Diffie-Hellman PKDS By www.jucs.org Published On :: 2011-07-04T16:04:45+02:00 Recently, IEEE 802.16 Worldwide Interoperability for Microwave Access (WiMAX for short) has provided us with low-cost, high efficiency and high bandwidth network services. However, as with the WiFi, the radio wave transmission also makes the WiMAX face the wireless transmission security problem. To solve this problem, the IEEE802.16Std during its development stage defines the Privacy Key Management (PKM for short) authentication process which offers a one-way authentication. However, using a one-way authentication, an SS may connect to a fake BS. Mutual authentication, like that developed for PKMv2, can avoid this problem. Therefore, in this paper, we propose an authentication key management approach, called Diffie-Hellman-PKDS-based authentication method (DiHam for short), which employs a secret door asymmetric one-way function, Public Key Distribution System (PKDS for short), to improve current security level of facility authentication between WiMAX's BS and SS. We further integrate the PKMv1 and the DiHam into a system, called PKM-DiHam (P-DiHam for short), in which the PKMv1 acts as the authentication process, and the DiHam is responsible for key management and delivery. By transmitting securely protected and well-defined parameters for SS and BS, the two stations can mutually authenticate each other. Messages including those conveying user data and authentication parameters can be then more securely delivered. Full Article