Voici les éléments 1 - 10 sur 593
  • Publication
    Métadonnées seulement
    Network Performance of the JBoss Application Server
    (: IEEE, 2013-10-22)
    Benothman, Nabil
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    Clere, Jean-Frederic
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    ; ;
    Maucherat, Remy
    JBoss Application Server (AS) uses java.io and the Apache Portable Runtime (APR) project to provide its HTTP connectors. Due to new features of upcoming specifications of the Java Enterprise Edition (Java EE), the existing connectors shall be replaced by modern non blocking Input/Outputs (I/Os). In this study, we review some modern I/O frameworks such as NIO.2 introduced by Java SE 7 and XNIO3 developed by JBoss. We compare their network performance by running a series of stress tests on client-server applications of limited functionality. As a result, we select NIO.2 as the most appropriate framework to specify and implement a new JBoss connector. Finally, we compare our newly implemented Java connector against the existing APR-based one by means of network performance measures.
  • Publication
    Métadonnées seulement
  • Publication
    Restriction temporaire
    Automatic Detection and Masking of Nonatomic Exception Handling
    (2004)
    Fetzer, Christof
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    ;
    Högstedt, Karin
  • Publication
    Métadonnées seulement
    Freemote Emulator: A lightweight and visual Java emulator for WSN
    (: Springer-Verlag Berlin, 2008)
    Maret, Timothée
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    Kummer, Raphaël
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    ;
    Wagen, Jean-Frédéric
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    Harju, Jarmo
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    Heijenk, Geert
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    Langendorfer, Peter
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    Siris, Vasilios A
    Research on Wireless Sensor Networks (WSNs) has developed highly optimized software environments fitting the limited hardware resource constraints of Motes. Unfortunately, these environments suffer from relatively complex programming models. Nowadays well known languages such as Java and optimized JVMs become available and simplify the application development for the Motes. Thus, we developed the Freemote Emulator which is a Java based emulator providing a lightweight emulation tool for emerging Java based Motes. It runs experiments in real time mixing real and emulated nodes. Its layered architecture and a set of predefined code templates allow developers to quickly produce runnable code for real and emulated nodes as well as predefined scenarios to help the newcomers to introduce into the system and WSNs. Our emulator provides as well a useful visualization tool based on a parametrizable slow down feature that helps to understand complex WSN behaviours and to debug tricky implementation problems. Finally, a single emulation can run on several computers, thus allowing programmers to conduct experiments with a pretty large number of emulated and real nodes.
  • Publication
    Métadonnées seulement
  • Publication
    Accès libre
    A Method to Optimize Ship Maneuvers for the Coordination of Hardkill and Softkill Weapons within a Frigate
    (2002)
    Blodgett, Dale E.
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    Chaib-draaa, Brahim
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    Plamondon, Pierrick
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    ;
    Bossé, Eloï
    The coordination of anti-air warfare hardkill and softkill weapon systems is an important aspect of command and control for a Frigate. Since the effectiveness of a particular weapon varies depending on the orientation of the Frigate with respect to the threats faced, a key element of the coordination process is to maneuver the Frigate to most effectively use all the weapons available. This paper shows that the environment surrounding the Frigate can be divided into six fundamental sectors for weapon engagement. The method to determine the general effectiveness of each sector for the threats faced is shown. A naïve Bayes method that determines the optimal positioning of the Frigate to most effectively use the hardkill and softkill weapons is presented. Also discussed are the different types of planners that were investigated for planning engagements for the hardkill and softkill weapon systems. Preliminary results comparing and rating these planners are shown, both with and without the recommended maneuvers.
  • Publication
    Accès libre
    Authorship attribution based on a probabilistic topic model
    This paper describes, evaluates and compares the use of Latent Dirichlet allocation (LDA) as an approach to authorship attribution. Based on this generative probabilistic topic model, we can model each document as a mixture of topic distributions with each topic specifying a distribution over words. Based on author profiles (aggregation of all texts written by the same writer) we suggest computing the distance with a disputed text to determine its possible writer. This distance is based on the difference between the two topic distributions. To evaluate different attribution schemes, we carried out an experiment based on 5408 newspaper articles (Glasgow Herald) written by 20 distinct authors. To complement this experiment, we used 4326 articles extracted from the Italian newspaper La Stampa and written by 20 journalists. This research demonstrates that the LDA-based classification scheme tends to outperform the Delta rule, and the Χ2 distance, two classical approaches in authorship attribution based on a restricted number of terms. Compared to the Kullback–Leibler divergence, the LDA-based scheme can provide better effectiveness when considering a larger number of terms.
  • Publication
    Restriction temporaire
  • Publication
    Accès libre
    Application layer traffic analysis of a Peer-to-Peer system
    (2008)
    Tutsch, Dietmar
    ;
    Babin, Gilbert
    ;
    Self-similar or multifractal behavior has been observed for LAN and Internet WAN (backbone) traffic. Investigations about this kind of behavior for application level protocols are rarely found because sessions or even applications are usually too short to be characterized in this direction. Only Telnet and FTP were examined so far. This paper analyzes the traffic shape of Peer-to-Peer (P2P) networks using the Gnutella protocol. Data was collected using a modified LimeWire servent. Self-similarity was estimated using a variance-time plot. The results show that Gnutella messages exhibit a self-similar shape, regardless of the message type.
  • Publication
    Restriction temporaire
    Automatic data partitioning in software transactional memories
    (2008)
    Riegel, Torvald
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    Fetzer, Christof
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