794 research outputs found

    An adaptive multilevel indexing method for disaster service discovery

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    With the globe facing various scales of natural disasters then and there, disaster recovery is one among the hottest research areas and the rescue and recovery services can be highly benefitted with the advancements of information and communications technology (ICT). Enhanced rescue effect can be achieved through the dynamic networking of people, systems and procedures. A seamless integration of these elements along with the service-oriented systems can satisfy the mission objectives with the maximum effect. In disaster management systems, services from multiple sources are usually integrated and composed into a usable format in order to effectively drive the decision-making process. Therefore, a novel service indexing method is required to effectively discover desirable services from the large-scale disaster service repositories, comprising a huge number of services. With this in mind, this paper presents a novel multilevel indexing algorithm based on the equivalence theory in order to achieve effective service discovery in large-scale disaster service repositories. The performance and efficiency of the proposed model have been evaluated by both theoretical analysis and practical experiments. The experimental results proved that the proposed algorithm is more efficient for service discovery and composition than existing inverted index methods

    Interim research assessment 2003-2005 - Computer Science

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    This report primarily serves as a source of information for the 2007 Interim Research Assessment Committee for Computer Science at the three technical universities in the Netherlands. The report also provides information for others interested in our research activities

    A Rewriting Logic Approach to Stochastic and Spatial Constraint System Specification and Verification

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    This paper addresses the issue of specifying, simulating, and verifying reactive systems in rewriting logic. It presents an executable semantics for probabilistic, timed, and spatial concurrent constraint programming ---here called stochastic and spatial concurrent constraint systems (SSCC)--- in the rewriting logic semantic framework. The approach is based on an enhanced and generalized model of concurrent constraint programming (CCP) where computational hierarchical spaces can be assigned to belong to agents. The executable semantics faithfully represents and operationally captures the highly concurrent nature, uncertain behavior, and spatial and epistemic characteristics of reactive systems with flow of information. In SSCC, timing attributes ---represented by stochastic duration--- can be associated to processes, and exclusive and independent probabilistic choice is also supported. SMT solving technology, available from the Maude system, is used to realize the underlying constraint system of SSCC with quantifier-free formulas over integers and reals. This results in a fully executable real-time symbolic specification that can be used for quantitative analysis in the form of statistical model checking. The main features and capabilities of SSCC are illustrated with examples throughout the paper. This contribution is part of a larger research effort aimed at making available formal analysis techniques and tools, mathematically founded on the CCP approach, to the research community.Comment: arXiv admin note: text overlap with arXiv:1805.0743

    A Pattern Language for Designing Application-Level Communication Protocols and the Improvement of Computer Science Education through Cloud Computing

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    Networking protocols have been developed throughout time following layered architectures such as the Open Systems Interconnection model and the Internet model. These protocols are grouped in the Internet protocol suite. Most developers do not deal with low-level protocols, instead they design application-level protocols on top of the low-level protocol. Although each application-level protocol is different, there is commonality among them and developers can apply lessons learned from one protocol to the design of new ones. Design patterns can help by gathering and sharing proven and reusable solution to common, reoccurring design problems. The Application-level Communication Protocols Design Patterns language captures this knowledge about application-level protocol design, so developers can create better, more fitting protocols base on these common and well proven solutions. Another aspect of contemporary development technics is the need of distribution of software artifacts. Most of the development companies have started using Cloud Computing services to overcome this need; either public or private clouds are widely used. Future developers need to manage this technology infrastructure, software, and platform as services. These two aspects, communication protocols design and cloud computing represent an opportunity to contribute to the software development community and to the software engineering education curriculum. The Application-level Communication Protocols Design Patterns language aims to help solve communication software design. The use of cloud computing in programming assignments targets on a positive influence on improving the Analysis to Reuse skills of students of computer science careers

    An information security model based on trustworthiness for enhancing security in on-line collaborative learning

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    L'objectiu principal d'aquesta tesi és incorporar propietats i serveis de la seguretat en sistemes d'informació en l'aprenentatge col·laboratiu en línia, seguint un model funcional basat en la valoració i predicció de la confiança. Aquesta tesi estableix com a punt de partença el disseny d'una solució de seguretat innovadora, basada en una metodologia pròpia per a oferir als dissenyadors i gestors de l'e-learning les línies mestres per a incorporar mesures de seguretat en l'aprenentatge col·laboratiu en línia. Aquestes guies cobreixen tots els aspectes sobre el disseny i la gestió que s'han de considerar en els processos relatius a l'e-learning, entre altres l'anàlisi de seguretat, el disseny d'activitats d'aprenentatge, la detecció d'accions anòmales o el processament de dades sobre confiança. La temàtica d'aquesta tesi té una naturalesa multidisciplinària i, al seu torn, les diferents disciplines que la formen estan íntimament relacionades. Les principals disciplines de què es tracta en aquesta tesi són l'aprenentatge col·laboratiu en línia, la seguretat en sistemes d'informació, els entorns virtuals d'aprenentatge (EVA) i la valoració i predicció de la confiança. Tenint en compte aquest àmbit d'aplicació, el problema de garantir la seguretat en els processos d'aprenentatge col·laboratiu en línia es resol amb un model híbrid construït sobre la base de solucions funcionals i tecnològiques, concretament modelatge de la confiança i solucions tecnològiques per a la seguretat en sistemes d'informació.El principal objetivo de esta tesis es incorporar propiedades y servicios de la seguridad en sistemas de información en el aprendizaje colaborativo en línea, siguiendo un modelo funcional basado en la valoración y predicción de la confianza. Esta tesis establece como punto de partida el diseño de una solución de seguridad innovadora, basada en una metodología propia para ofrecer a los diseñadores y gestores del e-learning las líneas maestras para incorporar medidas de seguridad en el aprendizaje colaborativo en línea. Estas guías cubren todos los aspectos sobre el diseño y la gestión que hay que considerar en los procesos relativos al e-learning, entre otros el análisis de la seguridad, el diseño de actividades de aprendizaje, la detección de acciones anómalas o el procesamiento de datos sobre confianza. La temática de esta tesis tiene una naturaleza multidisciplinar y, a su vez, las diferentes disciplinas que la forman están íntimamente relacionadas. Las principales disciplinas tratadas en esta tesis son el aprendizaje colaborativo en línea, la seguridad en sistemas de información, los entornos virtuales de aprendizaje (EVA) y la valoración y predicción de la confianza. Teniendo en cuenta este ámbito de aplicación, el problema de garantizar la seguridad en los procesos de aprendizaje colaborativo en línea se resuelve con un modelo híbrido construido en base a soluciones funcionales y tecnológicas, concretamente modelado de la confianza y soluciones tecnológicas para la seguridad en sistemas de información.This thesis' main goal is to incorporate information security properties and services into online collaborative learning using a functional approach based on trustworthiness assessment and prediction. As a result, this thesis aims to design an innovative security solution, based on methodological approaches, to provide e-learning designers and managers with guidelines for incorporating security into online collaborative learning. These guidelines include all processes involved in e-learning design and management, such as security analysis, learning activity design, detection of anomalous actions, trustworthiness data processing, and so on. The subject of this research is multidisciplinary in nature, with the different disciplines comprising it being closely related. The most significant ones are online collaborative learning, information security, learning management systems (LMS), and trustworthiness assessment and prediction models. Against this backdrop, the problem of securing collaborative online learning activities is tackled by a hybrid model based on functional and technological solutions, namely, trustworthiness modelling and information security technologies

    Fast, Interactive Worst-Case Execution Time Analysis With Back-Annotation

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    Abstract—For hard real-time systems, static code analysis is needed to derive a safe bound on the worst-case execution time (WCET). Virtually all prior work has focused on the accuracy of WCET analysis without regard to the speed of analysis. The resulting algorithms are often too slow to be integrated into the development cycle, requiring WCET analysis to be postponed until a final verification phase. In this paper we propose interactive WCET analysis as a new method to provide near-instantaneous WCET feedback to the developer during software programming. We show that interactive WCET analysis is feasible using tree-based WCET calculation. The feedback is realized with a plugin for the Java editor jEdit, where the WCET values are back-annotated to the Java source at the statement level. Comparison of this treebased approach with the implicit path enumeration technique (IPET) shows that tree-based analysis scales better with respect to program size and gives similar WCET values. Index Terms—Real time systems, performance analysis, software performance, software reliability, software algorithms, safety I
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