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Proceedings of 5th International Workshop on Parallel and Distributed Real-Time Systems and 3rd Workshop on Object-Oriented Real-Time Systems

3-3 April 1997

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  • Proceedings of 5th International Workshop on Parallel and Distributed Real-Time Systems and 3rd Workshop on Object-Oriented Real-Time Systems

    Publication Year: 1997
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    Freely Available from IEEE
  • Author index

    Publication Year: 1997, Page(s): 327
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    Freely Available from IEEE
  • Distributed real-time problem statement: the air defense system

    Publication Year: 1997, Page(s):119 - 129
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (708 KB)

    After thoroughly reading the problem statement on the air defense system I asked myself whether the problem statement was clear and unambiguous. In order to test the internal quality and consistency of the problem statement, I elaborated on the written text using the KISS method for object orientation. The goal of the KISS method is to attain an object-oriented information architecture that is bas... View full abstract»

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  • Comparing two-phase locking and optimistic concurrency control protocols in multiprocessor real-time databases

    Publication Year: 1997, Page(s):141 - 148
    Cited by:  Papers (5)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (720 KB)

    Previous studies (Haritsa et al., 1990) have shown that optimistic concurrency control (OCC) generally performs better than lock-based protocols in disk-based real-time database systems (RTDBS). We compare the two concurrency control protocols in both disk-based and memory-resident multiprocessor RTDBS. Based on their performance characteristics, a new lock-based protocol, called two phase locking... View full abstract»

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  • Real-time scheduling in video systems

    Publication Year: 1997, Page(s):309 - 318
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (900 KB)

    We consider the problem of mapping video algorithms onto systems of high-performance video signal processors with hard real-time constraints. The mapping problem under consideration is computationally hard due to the many constraints that need to be satisfied. We present a compact mathematical formulation which identifies the decision variables and the constraints that are involved. We demonstrate... View full abstract»

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  • Distributing time sensitive data in a COTS shared media environment

    Publication Year: 1997, Page(s):53 - 62
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (860 KB)

    Traditionally, the Navy has developed systems which distribute time-sensitive data using specialized components such as dedicated point-to-point communications links. Today, however the Navy is moving away from specialized solutions and toward Commercial-Off-the-Shelf (COTS) components to both keep up with the rapid pace of technology changes and to reduce system costs. COTS components are designe... View full abstract»

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  • DREAD: distributed real-time air defense system

    Publication Year: 1997, Page(s):108 - 118
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (744 KB)

    We present a solution to the problem of distributed air defense. The system consists of a set of 10 mobile nodes communicating with each other through a 500 KB/sec low bandwidth medium and via a surveillance satellite. These nodes are deployed on the battle-space and coordinate with each other in order to satisfy the system requirements. The system should be able to handle up to 10,000 tracks, ide... View full abstract»

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  • Automatic derivation of path and loop annotations in object-oriented real-time programs

    Publication Year: 1997, Page(s):257 - 262
    Cited by:  Papers (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (408 KB)

    This paper presents a new method, based on the notion of abstract interpretation, that can be used to derive path and loop annotations automatically for object-oriented real-time programs. Normally these annotations, necessary for the correct calculation of the worst case execution time (WCET), must be given manually by the programmer. The method is illustrated by the analysis of an example in Sma... View full abstract»

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  • Report on the case-study session [air defense system]

    Publication Year: 1997, Page(s):105 - 107
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (316 KB)

    As part of the call for papers for the workshop, a problem definition was given for which outline solutions were requested. The problem was designed to address a great many issues, for which the solutions given in the general literature would make conflicting assumptions, and thus would not be admissible. Problem areas addressed included algorithm design, temporal behaviour including hard deadline... View full abstract»

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  • TARTOS-tool box for active real-time object-oriented database system models

    Publication Year: 1997, Page(s):131 - 140
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (816 KB)

    When real-time databases are to be used in application environments, new requirements should be met by the underlying data model. While the relational data model is very good at modeling simple real-world entities with temporal and logical consistency, its limits are obvious when more modeling power is needed. An object-oriented approach can answer the modeling needs, but on the other hand it can ... View full abstract»

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  • Specification of hybrid systems in cTLA+

    Publication Year: 1997, Page(s):212 - 216
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (412 KB)

    cTLA+ is a compositional specification and verification technique which is based on Leslie Lamport's (1994) Temporal Logic of Actions TLA. cTLA+ supports modular process type definitions and the composition of processes to systems. Processes can model components of an implementation. Moreover they can represent modular logical constraints. Constraint-oriented structures of system specifications ar... View full abstract»

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  • Toward a scalable design for command and control systems

    Publication Year: 1997, Page(s):43 - 52
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1052 KB)

    Command and control systems exist in a world of constantly shifting demands and expectations; therefore, producing scalable, evolvable systems has always been a priority of system designers. However the need to meet performance requirements has often been a restraint on scalability goals. Advances in the speed and capacity of computational and communications equipment have substantially increased ... View full abstract»

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  • A transaction-based temporal data model for real-time databases

    Publication Year: 1997, Page(s):149 - 158
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (772 KB)

    We propose a real-time database model that deals with the temporal nature of data. Previous models assigned validity intervals with data items. A value of a data item is then only valid within the corresponding interval. In the new model, it is recognized that validity depends on the usage of the data item, therefore temporal validity is a characteristic of transactions, rather than of data items.... View full abstract»

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  • On the design of a dynamic distributed real-time environment

    Publication Year: 1997, Page(s):251 - 256
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (624 KB)

    Development of distributed real-time applications requires tools and methods ranging from the design process down to the run-time system. This paper describes an approach towards an integrated object-oriented real-time environment, providing a new conceptual structuring method, distributed dynamic scheduling, and a real-time executive, based on a standard real-time operating system. TaskPairs are ... View full abstract»

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  • Implementation of the Hartstone Distributed Benchmark for hard real-time distributed systems: results and conclusions

    Publication Year: 1997, Page(s):98 - 103
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (396 KB)

    This paper presents a first time approach for the implementation of the Hartstone Distributed Benchmark (HDB) for hard real-time distributed systems. From the series of experiments, as defined in the original HDB paper, six experiments have been implemented. The main idea behind the HDB is the definition of a number of (host processor) tasks on each node which exchange messages with corresponding ... View full abstract»

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  • Modeling and analysis of hybrid systems: a new approach integrating Petri nets and differential equations

    Publication Year: 1997, Page(s):234 - 238
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (312 KB)

    Hybrid technical systems combine discrete-state event-driven and continuous-state time-driven behaviour. In this contribution, a general modeling formalism for such systems is proposed. The discrete subsystem is represented by an interpreted Petri net. In addition to external continuous inputs, discrete variables dependent on the net marking affect the continuous subsystem which is a time-driven s... View full abstract»

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  • Multiple node-disjoint path protocol for virtual paths in ATM networks

    Publication Year: 1997, Page(s):91 - 97
    Cited by:  Papers (2)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (400 KB)

    This paper presents a routing protocol for finding multiple node-disjoint paths between two nodes in a computer network. Finding the maximal number of node-disjoint paths is one of the most important themes in ATM networks to increase the level of network reliability. In ATM networks, the virtual path (VP) concept is appropriate to network control for failure restoration (path restoration). In the... View full abstract»

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  • Automatic effective verification method for distributed and concurrent systems using timed language inclusion

    Publication Year: 1997, Page(s):193 - 200
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (624 KB)

    We propose a specification and verification method for distributed systems. We can easily specify fairness and timing constraints, and can effectively verify distributed systems by our proposed method. In order to specify fairness, an enable condition and a performed condition are attached to a finite set of states in our proposed specification method. In order to effectively verify distributed sy... View full abstract»

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  • Window theory of local image processing (IP): a framework for mapping local IP algorithms onto local IP systems under real time constraints

    Publication Year: 1997, Page(s):302 - 308
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (828 KB)

    This paper introduces a window theory of local image processing (IP). An associated framework for mapping local IP algorithms onto local IP systems is presented. The window theory relies on two fundamental concepts: image windows and window operators. The starting point of the mapping methodology is thereby the local IP algorithm specifications in the form of instruction sequences referring to win... View full abstract»

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  • Multi-paradigm programming in large control systems

    Publication Year: 1997, Page(s):27 - 32
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (568 KB)

    Due to the complex functionality of large control systems, many different application domains are involved in their implementation. Despite this diversity, modern control systems are implemented according to the (conventional) imperative programming model. Multi-paradigm programming is an approach toward system development that is based on more than one programming model. By choosing a domain-spec... View full abstract»

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  • Integrated scheduling of tasks and messages in distributed real-time systems

    Publication Year: 1997, Page(s):64 - 71
    Cited by:  Papers (1)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (696 KB)

    The scheduling of tasks in distributed real-time systems has attracted many researchers in the recent past. The distributed real-time system considered here consists of uniprocessor or multiprocessor nodes connected through a multihop network. Scheduling in such a system involves scheduling of dynamically arriving tasks within a node (local scheduling) and migration of tasks across the network (gl... View full abstract»

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  • A real-time Java server for Real-Time Mach

    Publication Year: 1997, Page(s):319 - 325
    Cited by:  Papers (2)  |  Patents (10)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (480 KB)

    The authors have developed a real-time Java server on the Real-Time Mach microkernel which is suitable for embedded systems and distributed real-time systems. By implementing it as a user-level server on Real-Time Mach, applications such as WWW browsers and embedded applications can both execute Java byte codes. They describe the real-time issues in Java and the architecture of the Java server. Th... View full abstract»

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  • A pre-run-time scheduling algorithm for object-based distributed real-time systems

    Publication Year: 1997, Page(s):160 - 167
    Cited by:  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (792 KB)

    The most important goal in hard real-time systems is to guarantee that all timing constraints are satisfied. Even though object-based techniques (which contain reusable software components) are used to manage the complexity in the software development process of such systems, execution efficiency may have to be sacrificed, due to the large number of procedure calls and contention for accessing sof... View full abstract»

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  • An evolutionary approach to the construction of new-generation software-intensive satellite control systems

    Publication Year: 1997, Page(s):263 - 268
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (520 KB)

    In the development of on-board embedded real-time systems an important proportion of the critical requirements arise as second-order requirements. The feasibility of the logical model, initially established to meet a relatively stable set of user requirements, needs to be reconfirmed in the face of the more elusive implementation constraints and the limitations imposed by the execution environment... View full abstract»

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  • VERDICT-a tool for model-based verification of real-time logic process controllers

    Publication Year: 1997, Page(s):217 - 221
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (368 KB)

    This paper provides an overview of a project in which a practically applicable tool for the algorithmic formal verification of logic controllers (including timers) for processes with at least piecewise continuous dynamics is developed. In contrast to existing verification techniques from computer science, the presented approach is based on a model of the uncontrolled plant. Condition/event systems... View full abstract»

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