853 research outputs found

    Testing real-time systems using TINA

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    The paper presents a technique for model-based black-box conformance testing of real-time systems using the Time Petri Net Analyzer TINA. Such test suites are derived from a prioritized time Petri net composed of two concurrent sub-nets specifying respectively the expected behaviour of the system under test and its environment.We describe how the toolbox TINA has been extended to support automatic generation of time-optimal test suites. The result is optimal in the sense that the set of test cases in the test suite have the shortest possible accumulated time to be executed. Input/output conformance serves as the notion of implementation correctness, essentially timed trace inclusion taking environment assumptions into account. Test cases selection is based either on using manually formulated test purposes or automatically from various coverage criteria specifying structural criteria of the model to be fulfilled by the test suite. We discuss how test purposes and coverage criterion are specified in the linear temporal logic SE-LTL, derive test sequences, and assign verdicts

    A Web-Based Collaborative Multimedia Presentation Document System

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    With the distributed and rapidly increasing volume of data and expeditious development of modern web browsers, web browsers have become a possible legitimate vehicle for remote interactive multimedia presentation and collaboration, especially for geographically dispersed teams. To our knowledge, although there are a large number of applications developed for these purposes, there are some drawbacks in prior work including the lack of interactive controls of presentation flows, general-purpose collaboration support on multimedia, and efficient and precise replay of presentations. To fill the research gaps in prior work, in this dissertation, we propose a web-based multimedia collaborative presentation document system, which models a presentation as media resources together with a stream of media events, attached to associated media objects. It represents presentation flows and collaboration actions in events, implements temporal and spatial scheduling on multimedia objects, and supports real-time interactive control of the predefined schedules. As all events are represented by simple messages with an object-prioritized approach, our platform can also support fine-grained precise replay of presentations. Hundreds of kilobytes could be enough to store the events in a collaborative presentation session for accurate replays, compared with hundreds of megabytes in screen recording tools with a pixel-based replay mechanism

    Complex Event Processing Modeling by Prioritized Colored Petri Nets

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    Complex event processing (CEP) is a technology that allows us to process and correlate large volumes of data by using event patterns, aiming at promptly detecting specific situations that could require special treatment. The event types and event patterns for a particular application domain are implemented by using an event processing language (EPL). Although some current model-driven tools allow end users to easily define these patterns, which are then transformed automatically into a particular EPL, the generated code is syntactically but not semantically validated. To deal with this problem, a prioritized colored Petri net (PCPN) model for CEP is proposed and conducted in this paper. This well-known graphical formalism together with CPNTools makes possible the modeling, simulation, analysis, and semantic validation of complex event-based systems. To illustrate this approach, a case study is presented, as well as a discussion on the benefits from using PCPN for modeling CEP-based systems.El procesamiento de eventos complejos (CEP) es una tecnología que nos permite procesar y correlacionar grandes volúmenes de datos utilizando patrones de eventos, con el objetivo de detectar rápidamente situaciones específicas que podrían requerir un tratamiento especial. Los tipos de eventos y patrones de eventos para un dominio de aplicación particular se implementan utilizando un lenguaje de procesamiento de eventos (EPL). Aunque algunas herramientas actuales impulsadas por modelos permiten a los usuarios finales definir fácilmente estos patrones, que luego se transforman automáticamente en un EPL particular, el código generado se valida sintácticamente pero no semánticamente. Para abordar este problema, en este documento se propone y lleva a cabo un modelo de red de Petri coloreada y priorizada (PCPN) para CEP. Este formalismo gráfico bien conocido junto con CPNTools hace posible la modelización, simulación, análisis y validación semántica de sistemas basados en eventos complejos. Para ilustrar este enfoque, se presenta un estudio de caso, así como una discusión sobre los beneficios de usar PCPN para modelar sistemas basados en CEP.This work was supported in part by the Spanish Ministry of Science and Innovation and the European Union FEDER Funds with the Project DArDOS entitled Formal development and analysis of complex systems in distributed contexts: foundations, tools and applications under Grant TIN2015-65845-C3, subprojects 2-R and 3-R, and the Research Network on Services Science and Engineering under Grant TIN2014-53986-REDT, and in part by the University of Cádiz under Project PR2016-032

    Executable Architectures and their Application to a Geographically Distributed Air Operations Center

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    Integrated Architectures and Network Centric Warfare represent two central concepts in the Department of Defense\u27s (DoD) on-going transformation. The true power of integrated architectures is brought to bear when they are combined with simulation to move beyond a static representation and create an executable architecture. This architecture can then be used to experiment with system configurations and parameter values to guide employment decisions. The process of developing and utilizing an executable architecture will be employed to assess an Air Operations Center (AOC). This thesis applies and expands upon the methodology of Dr. Alexander Levis, former Chief Scientist of the Air Force, to the static architecture representing the Aerospace Operations Center (AOC). Using Colored Petri Nets and other simulation tools, an executable architecture for the AOC\u27s Air Tasking Order (ATO) production thread was developed. These models were then used to compare the performance of a current, forward-deployed AOC configuration to three other potential configurations that utilize a network centric environment to deploy a portion of the AOC and provide reach-back capabilities to the non-deployed units. Performance was measured by the amount of time required to execute the ATO cycle under each configuration. Communication requirements were analyzed for each configuration and stochastic delays were modeled for all transactions in which requirements could not be met due to the physical configuration of the AOC elements. All four configurations were found to exhibit statistically different behavior with regard to ATO cycle time

    Facilitating the Quantitative Analysis ofComplexEvents through a Computational Intelligence Model-Driven Tool

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    Complex event processing (CEP) is a computational intelligence technology capable of analyzing big data streams for event pattern recognition in real time. In particular, this technology is vastly useful for analyzing multicriteria conditions in a pattern, which will trigger alerts (complex events) upon their fulfillment. However, one of the main challenges to be faced by CEP is how to define the quantitative analysis to be performed in response to the produced complex events. In this paper, we propose the use of the MEdit4CEP-CPN model-driven tool as a solution for conducting such quantitative analysis of events of interest for an application domain, without requiring knowledge of any scientific programming language for implementing the pattern conditions. Precisely, MEdit4CEP-CPN facilitates domain experts to graphically model event patterns, transform them into a Prioritized Colored Petri Net (PCPN) model, modify its initial marking depending on the application scenario, and make the quantitative analysis through the simulation and monitor capabilities provided by CPN tools

    Modeling And Analysis Of Cascading Effects Of Weapons Of Mass Destruction (Wmd) Events On Critical Infrastructure Systems

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    This research studies how the global network behaves after a Weapon of Mass Destruction (WMD) attack. The goal is to find a reliable model that will help capture the behavior of the network in the event of a WMD attack and then proceed to a systematic analysis of that model. We discuss a hierarchical model that visualizes how a WMD attack will impact different infrastructure systems

    Practical Application Of Uml Activity Diagrams For The Generation Of Test Cases

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    Software testing and debugging represents around one third of total effort in development projects. Different factors which have influence on poor practices of testing have been identified through specific surveys. Amongst several, one of the most important is the lack of efficient methods to exploit development models for generating test cases. This paper presents a new method for automatically generating a complete set of functional test cases from UML activity diagrams complementing specification of use cases. Test cases are prioritized according to software risk information. Results from experiences with more than 70 software professionals/experts validate benefits of the method. Participants also confirm its interest and effectiveness for testing needs of industry

    Simulation Modelling Practice and Theory

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    The influx of data in the world today needs analysis that no one method can handle. Some reports estimated the influx of data would reach 163 zitabytes by 2025, hence the need for simulation and modeling theory and practice. Simulation and modeling tools and techniques are most important in this day and age. While simulation carries the needed work, tools for visualizing the results help in the decision-making process. Simulation ranges from a simple queue to molecular dynamics, including seismic reliability analysis, structural integrity assessment, games, reliability engineering, and system safety. This book will introduce practitioners, researchers, and novice users to simulation and modeling, and to the world of imagination
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