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Euromicro Conference, 2004. Proceedings. 30th

Date 31 Aug.-3 Sept. 2004

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Displaying Results 1 - 25 of 93
  • Querying reflexive component-based architectures

    Page(s): 127 - 134
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (295 KB) |  | HTML iconHTML  

    In the context of large-scale distributed component-based systems, This work motivates the need for and defines a general open query service. This query service allows for retrieving and selecting components from both repositories and deployed running systems. The problem of retrieving components from repositories has already been tackled by many research works whose purpose is to construct systems by assembling reusable components, typically in the context of COTS components. However, the proposed query services allows for an uniform efficient associative access to both repositories and running systems, while being based on distributed database techniques, which is the main contribution in This work. View full abstract»

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  • Runtime management of quality specification for QoS-aware components

    Page(s): 84 - 91
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (7208 KB) |  | HTML iconHTML  

    Currently, the interface description languages in component infrastructures provides support for the description of functional properties, and structures such as deployment descriptors provide support to configure some specific extra-functional aspects (e.g. persistence, security, transactions). But the infrastructures do not provide support for the description and management of general QoS (e.g. latencies, reliability, and availability). Currently there are available some approaches to solve this problem. We propose some solutions to integrate the QoS specification of model driven approaches and infrastructures for components. The component reuses this information for QoS management purposes. In our approach, QoS-aware models and infrastructures use compatible QoS specification languages. In component infrastructures, basic structures such as containers are good candidates to integrate the QoS management tasks (e.g. negotiation, adaptation and monitoring). Management tasks access to QoS repository to get information, evaluate expressions, and test monitored values. The QoS specification repository handles the QoS information and provides some basic operations (e.g. evaluation of constraints and introspection for adaptation). View full abstract»

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  • Reconfiguration-based QoS management in multimedia streaming applications

    Page(s): 248 - 255
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (497 KB) |  | HTML iconHTML  

    Multimedia applications are currently being deployed over dynamic and heterogeneous environments. They operate on devices with diverse computation capabilities in terms of processing, storage and display capabilities. In such environments, resource availability is subject to unexpected fluctuations (such as network bandwidth, battery life-time, CPU, etc.). This obliges applications to reconfigure their behavior accordingly in order to maintain an acceptable quality of service (QoS). This work addresses this aspect and describes a framework for a reconfiguration-based QoS management in multimedia streaming applications. Our objective is to relieve developers from dealing with the complexity of multimedia applications and their reconfiguration requirements. The framework provides a high-level specification language enabling an easy description of applications and their reconfiguration policies. A powerful component-based implementation is used for mapping specifications into run-time applications. Several experiments in different scenarios are reported to argue our design choices, and to show the impact of reconfigurations on the perceived QoS. View full abstract»

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  • Enhanced SIP communication services by context sharing

    Page(s): 272 - 279
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (299 KB) |  | HTML iconHTML  

    Communication plays a central in our society. It affects our private lives as well as business activities. Humans usually observe the environment and the communication partner with all their senses. The perceived information is evaluated to deduce the context of the targeted communication partner. However, distant interpersonal communication does not provide a priori knowledge of the called party's current situation, condition or mood - the callee's context. Current communication systems do not offer satisfying technical means to support context sharing between communication partners. The proposed solution in This work is based on an enhancement of the session initiation protocol (SIP) for IP telephony systems. Different mechanism of sharing context among communication peers have been investigated, implemented and evaluated. View full abstract»

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  • A framework for protecting Web services with IPsec

    Page(s): 290 - 297
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (297 KB) |  | HTML iconHTML  

    This work proposes a WSDL security extension for describing IPsec policies in Web services negotiations. The proposed extension is based on the policy model proposed by IETF for describing IPsec policies. Besides the model, the paper presents a framework for embedding IPsec negotiations in Web services applications. The paper also presents the results of the overhead evaluation introduced by the use IPsec to protect Web services applications under different configurations. View full abstract»

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  • Security concerns of legally sensitive Web portals

    Page(s): 544 - 550
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (281 KB) |  | HTML iconHTML  

    In contemporary information society the use of fundamental rights is increasingly focused on the use of Web information systems (IS). Therefore, legal aspects regulating users' rights and commitments should be given more attention in the development of IS. Mainly the section data protection and securing the integrity of IS systems should mainly be considered. The purpose of This work is to present research in progress and to add some security related observations. As a result This work gives some different viewpoints for the design and implementation of legally sensitive Web portals and builds up a concept to improve such systems. View full abstract»

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  • Model-based generation of business component architectures

    Page(s): 176 - 183
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (913 KB) |  | HTML iconHTML  

    The definition of business component architecture represents a challenging goal in component-based software engineering. Despite the several approaches to this subject, difficulties still arise when designing and assembling components to provide an integrated solution. The problem we focus on this work is the absence of rules that make use of analysis models to guide the architect throughout the specification of a component-based architecture. This lack of support results in a series of laborious and nonautomated activities. In order to increase the abstraction level of the business component architecture specification task and reduce design efforts, this work presents a practical proposal aimed at generating business components from analysis models. To achieve this goal, some rules and procedures have been researched and evolved, guiding the software architect during the development process. View full abstract»

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  • Multi-homing tunnel broker

    Page(s): 282 - 289
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (313 KB) |  | HTML iconHTML  

    A proper support for communications has to provide fault tolerance capabilities such as the preservation of established connections in case of failures. Multihoming addresses this issue, but the currently available solution based in massive BGP route injection presents serious scalability limitations, since it contributes to the exponential growth of the BGP table size. An alternative solution based on the configuration of tunnels between the multihomed site exit routers and the ISP border routers has been proposed for IPv6 in RFC 3178. However, the amount of manual configuration imposed by this solution on the ISP side prevents its wide adoption. In particular, this solution requires at the ISP the manual configuration of a tunnel endpoint per each multihomed client that it serves. We present a multihoming tunnel broker (MHTB) that provides automatic creation of the tunnel endpoint at the ISP side. View full abstract»

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  • GridSphere: an advanced portal framework

    Page(s): 412 - 419
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (550 KB) |  | HTML iconHTML  

    In traditional Web application development, very few libraries exist to make portal development easy. In general, many homegrown and vertical solutions exist and very little code is shared or reused. Finally with the emergence of some critical new Web technologies, Web application development is focusing more on reusable solutions and software. The GridSphere portal framework provides a standards based portal for the easy development of modular Web components, called portlets. Portlets are defined by a standard API and provide a model for developing new portal components that can be shared and exchanged by various portlet containers. GridSphere provides both a portlet container, a collection of core portlets and an advanced user interface library that makes developing new portlets easier for application developers. This work discusses briefly the GridSphere portal architecture including the layout engine, support for two portlet API implementations and the portlet services model. View full abstract»

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  • Analysis and prediction of performance for evolving architectures

    Page(s): 22 - 31
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (331 KB) |  | HTML iconHTML  

    This work describes a method for the "analysis and prediction of performance for evolving architectures " (APPEAR). The method aims at performance estimation of adapted parts of software product families during the architecting phase. It combines both structural and statistical techniques in a flexible way, that is, it allows choosing which part of the component is structurally described, modeled and simulated, and which part is statistically evaluated. The method was exemplified by case studies in the consumer electronics and the medical imaging system domains. The results of the initial validation of the method are encouraging. View full abstract»

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  • A framework for interactive visualization of component-based software

    Page(s): 567 - 574
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (429 KB) |  | HTML iconHTML  

    We advocate the use of visual tooling for the development and maintenance of component-based software systems. Our contribution is twofold. First, we demonstrate how an interactive visualization tool effectively supports understanding large component based software. Secondly, we show how to design such a tool in order to make it applicable for a wide range of component systems and investigation goals. We demonstrate our approach by several visualization scenarios for real-world systems. View full abstract»

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  • Introducing agile methods: three years of experience

    Page(s): 334 - 341
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (291 KB) |  | HTML iconHTML  

    The work summarizes three years of experience of introducing agile practices in academic environments. The perceptions of students from four different academic programs (Diploma, Applied Bachelor's, Bachelor's and Master's) from two institutions are analyzed. Specifically, pair programming, test-driven development and project planning using the planning game were studied in detail. Overwhelmingly, students' experiences are positive and their opinions indicate the preference to continue to use agile practices if allowed. No major problems with agile techniques appeared in the evaluation contexts and benefits in these contexts have been seen. View full abstract»

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  • Improving software process in agile software development projects: results from two XP case studies

    Page(s): 310 - 317
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (294 KB) |  | HTML iconHTML  

    One of the agile principles is that software development teams should regularly reflect on how to improve their practices to become more effective. Some systematic approaches have been proposed on how to conduct such a self-reflection process, but little empirical evidence yet exits. The empirical results are reported from two XP (extreme programming) projects where the project teams conducted "post-iteration workshops" after all process iterations in order to improve and optimize working methods. Both qualitative and quantitative data from the total of eight post-iteration workshops is presented in order to evaluate and compare the findings of the two projects. The results show the decline of both positive and negative findings, as well as the narrower variation of negative findings and process improvement actions towards the end of both projects. In both projects, the data from post-iteration workshops indicate increased satisfaction and learning of project teams. View full abstract»

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  • Implications of traffic characteristics on quality of service in broadband multi service networks

    Page(s): 196 - 204
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (387 KB) |  | HTML iconHTML  

    Quality of service (QoS) aspects in telecommunication networks interrelate requirements of users and applications with network architectures supporting relevant transmission properties. New challenges arise in multiservice platforms with increasing variety of service demands, which comes together with a higher variability in traffic profiles. We try to give a general and comprehensive picture of the effect of traffic characteristics and control mechanisms on quality of service (QoS). Broadband access platforms are considered from source traffic profiles to QoS aware dimensioning for aggregated traffic in the IP backbone. Networks based on multiprotocol label switching (MPLS) are included, which combine capabilities for network monitoring, planning and traffic engineering with full support of differentiated and integrated services as main QoS concepts introduced by the Internet engineering task force (IETF). View full abstract»

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  • Attitudes and perceptions related to information security - case: Rotuaari

    Page(s): 538 - 543
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (263 KB) |  | HTML iconHTML  

    The purpose of this research was to evaluate security awareness related to information technology in order to be able to develop information security communication procedures further. The research was conducted as a case study in the context of a mobile multimedia service research project. The research data was gathered with qualitative, semistructured theme interviews and focus group interviews. The interviewees were divided in four groups, vendors, content providers, technical researchers and nontechnical researchers. The results indicate that at the moment there are knowledge and information channel deficits especially among people who do not have technical education or experience. These deficits cause uncertainty related to own possibilities to use new technology. The concept of information security, factors affecting in it and risks related to it are not clearly understood, which may cause difficulties to the development of the information society. View full abstract»

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  • Implementing SIP and H.323 signalling as Web services

    Page(s): 265 - 271
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (339 KB) |  | HTML iconHTML  

    Nowadays, existing voice-over-IP (VoIP) clients are signalling protocol dependant. This means that they can only support one signalling protocol. One disadvantage of these VoIP clients is that they are rich clients, and the other is that the problem of interoperability between two clients supporting different signalling protocols must be solved by a signalling protocol translator. We propose a VoIP Web services architecture, taking advantage of the Web services technology to solve the above problems. This work explores the design and implementation of a VoIP Web services system architecture. We first propose a VoIP Web service architecture, and then we focus mainly on designing the signalling protocol Web services, and illustrate the call procedures between the simple client and the normal H.323/SIP client under this architecture. We also present the experience in implementing the prototype for the H.323/SIP Web services, and finally give some considerations about the implementation. View full abstract»

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  • Improving requirements management in extreme programming with tool support - an improvement attempt that failed

    Page(s): 342 - 351
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (379 KB) |  | HTML iconHTML  

    While extreme programming (XP) relies on certain principles, it requires an extensive set of tools to enable an effective execution of its practices. In many companies, putting stories on the board may not be sufficient for managing rapidly changing requirements. The objective of This work is to report the results from a study where a requirement management tool - the Storymanager - was developed to meet the needs of a XP project team. The tool was used in a case project where a mobile application for real markets was produced. The tool was dropped by the team only after two releases. The reasons of the process improvement failure are addressed in This work. The principal results show that the tool was found to be too difficult to use and that it failed to provide as powerful a visual view as the paper-pen board method. The implications of these findings are addressed for both the practitioners and researchers in the field. View full abstract»

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  • CoBFIT: A component-based framework for intrusion tolerance

    Page(s): 591 - 600
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (307 KB) |  | HTML iconHTML  

    We present the architecture of CoBFIT, a component-based framework for building intrusion-tolerant distributed systems. The CoBFIT framework, by virtue of its design and implementation principles, can serve as a convenient base for building components that implement intrusion-tolerant protocols and for combining these components in an efficient manner to provide a number of services for dependability. For example, We describe the CoBFIT implementation of a prototype intrusion-tolerant group communication system that includes services such as reliable multicast, group membership management, and total ordering of multicast messages. View full abstract»

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  • Melisa - a distributed multimedia system for multiplatform interactive sports content broadcasting

    Page(s): 222 - 229
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (361 KB) |  | HTML iconHTML  

    The new generation of television (TV) viewers is currently being confronted and becoming acquainted with a series of technological developments in the realm of consumer electronics and gaming that raise their expectations for similar advances in TV broadcasts. The Melisa platform aims at the cross-media broadcasting of sports eevents featurin interactive advertising and sports-related games over digital television and next generation mobile network infrastructures. The platform provides services for optimal presentation of complex interactive real time video content, for advertisement and an advanced real-time gaming (betting) engine. The Melisa server receives information from geographically separated betting, advertisement and video capturing servers that enforces the notion of a distributed system design for information exchange. The resulted business model offers great flexibility in system configuration both in scalability and physical layout configuration. View full abstract»

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  • DesCOTS: a software system for selecting COTS components

    Page(s): 118 - 126
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (738 KB) |  | HTML iconHTML  

    Selection of commercial-off-the-shelf software components (COTS components) has a growing importance in software engineering. Unfortunately, selection projects have a high risk of ending up into abandonment or yielding an incorrect selection. The use of some software engineering practices such as the definition of quality models can reduce this risk. We defined a process for COTS components selection based on the use of quality models and we started to apply it in academic and industrial cases. The need of having a tool to support this process arose and, although some tools already exist to partially support the involved activities, none of them was suitable enough. Because of this we developed DesCOTS, a software system that embraces several tools that interact to support the different activities of our process. The system has been designed taking into account not only functional concerns but also nonfunctional aspects such as reusability, interoperability and portability. We present in this paper the different subsystems of DesCOTS and discuss about their applicability. View full abstract»

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  • Impact of statechart implementation techniques on the effectiveness of fault detection mechanisms

    Page(s): 136 - 143
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (288 KB) |  | HTML iconHTML  

    This work presents the analysis of an experiment series aiming at the discovery of the impact of two inherently different statechart implementation methods on the behavior of the resulting executables in the presence of faults. The discussion identifies the key features of implementation techniques influencing the effectiveness of standard fault detection mechanisms (memory protection, assertions etc.) and an advanced statechart-level watchdog scheme used for detecting the deviations from the abstract implementation-independent behavioral specification. View full abstract»

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  • A survey on software components search and retrieval

    Page(s): 152 - 159
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (586 KB) |  | HTML iconHTML  

    In the literature, several works that explore component search may be found, since the decade of 90 until today. Current research on component-based software engineering (CBSE) point to the creation of component markets, which allow reuse to occur at large scale. Although search mechanisms play a very important role in such markets, the literature is quite poor in putting these two concerns together. This work presents a survey about the main research on component search, and discusses how should be a mechanism to efficiently search components, in order to offer support for future component markets. View full abstract»

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  • Distribution patterns of effort estimations

    Page(s): 422 - 429
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (287 KB) |  | HTML iconHTML  

    Effort estimations within software development projects and the ability to work within these estimations are perhaps the single most important, and at the same time inadequately mastered, discipline for overall project success. This study examines some characteristics of accuracies in software development efforts and identifies patterns that can be used to increase the understanding of the effort estimation discipline as well as to improve the accuracy of effort estimations. The study complements current research by taking a more simplistic approach than usually found within mainstream research concerning effort estimations. It shows that there are useful patterns to be found as well as interesting causalities, usable to increase the understanding and effort estimation capability. View full abstract»

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  • Predicting real-time properties of component assemblies: a scenario-simulation approach

    Page(s): 40 - 47
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (363 KB) |  | HTML iconHTML  

    This work addresses the problem of predicting timing properties of multitasking component assemblies during the design phase. For real-time applications, it is of vital importance to guarantee that the timing requirements of an assembly are met. We propose a simulation-based approach for predicting the real-time behaviour of an assembly based on models of its constituent components. Our approach extends the scenario-based method in [J. Muskens et al. (2004)] by offering a system model that is tailored to the domain of real-time applications. Contributions of This work include the possibility to handle the following features: mutual exclusion, combinations of aperiodic and periodic tasks and synchronization constraints. The analytical approach we used in previous work cannot handle these features. Therefore, we introduce the simulation-based approach. Our simulator provides data about dynamic resource consumption and real-time properties like response time, blocking time and number of missed deadlines per task. We have validated our approach using a video-decoder application. View full abstract»

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  • Investigations in applying metrics to multi-view architecture models

    Page(s): 372 - 379
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (674 KB) |  | HTML iconHTML  

    The goal of our research is to develop industry-proof software architecture and design metrics. We identify a number of problems that arise in computing software architecture and design metrics in industrial settings that were not encountered in computing source-code metrics. These problems include the absence of a single, unifying representation for architectures and they arise from the fact that architecture diagrams are used in an informal manner. We describe our approach towards defining metrics for architectures and designs which are represented in the 4+1 views paradigm using UML. We report our experiences with architectural metrics in industrial settings. View full abstract»

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