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Real Time, 1989. Proceedings., Euromicro Workshop on

Date 14-16 Jun 1989

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Displaying Results 1 - 25 of 27
  • Analysis and implementation of hierarchical real-time architectures

    Publication Year: 1989, Page(s):66 - 73
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (532 KB)

    Multiprocessor architectures for real-time applications in signal processing and control are described. An investigation of these architectures to determine their performance under a variety of applications and task mixes is presented. The goal is to develop tools for configuring applications on multiple processor systems so that real-time constraints are met. The approach used is to solve queuein... View full abstract»

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  • Multiple processor architectures for real time parameter estimation

    Publication Year: 1989, Page(s):93 - 100
    Cited by:  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (412 KB)

    Several multiple processor architectures which allow parallel implementations of the recursive least-squares estimation algorithm are presented and evaluated. The multiple processor architectures are based on the transputer which supports the process model of computation and allows the distribution of concurrent processes on different processors. The computational complexity of the estimation algo... View full abstract»

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  • Testing and debugging in real time systems-design decisions to use a distributed computer architecture in a real time application

    Publication Year: 1989, Page(s):101 - 106
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (432 KB)

    A description is given of the design decisions that lead to a distributed computer architecture along with the computer's test and debugging facilities. This architecture was developed for an autonomous mobile robot and supports the special data processing structure of such real-time applications. Time behavior considerations led to the use of a distributed computer architecture with static task d... View full abstract»

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  • Time-closed layer: a design principle for time-critical applications

    Publication Year: 1989, Page(s):138 - 145
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (352 KB)

    A design principle, called time-closed layer, is developed for specifying and designing time-critical computing systems. The principle is based on the pseudoserialization to the systems activities. Each sub-activity is represented by a layer that satisfies both communication and time closedness properties. Operations such as SEQ, WHILE, ELSE, and ALT may be performed on layers. These operations al... View full abstract»

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  • Scheduling problems while compiling the real-time language Lustre on the digital signal processor ST18930

    Publication Year: 1989, Page(s):178 - 186
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (524 KB)

    An experiment in optimizing the computations of loops on a digital signal processor is reported. Working with a simple pipelined monoprocessor, the DSP ST18930, the goal was to optimize the code generated by a dedicated version of the Lustre compiler. If there is a computation loop whose end may be overlapped with the beginning of the next loop, the problem is to minimize the delay between two suc... View full abstract»

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  • Pattern-directed real-time execution of SA/RT specifications

    Publication Year: 1989, Page(s):3 - 9
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (440 KB)

    Initial results with an experimental run-time system are reported. The run-time system makes possible real-time execution of software specifications created according to the structured analysis for real-time systems (SA/RT) techniques. A prototype of the run-time system is implemented in C language and runs in an Apple MacIntosh II/MPW C environment. Average execution speeds of approximately 2000 ... View full abstract»

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  • Designing time critical systems with TACT

    Publication Year: 1989, Page(s):74 - 82
    Cited by:  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (560 KB)

    The authors propose a small set of extensions with language and run-time support, based on reliable communication and atomic actions, to the concurrent programming language OCCAM2. A description of the syntax and a formal definition of the semantics of the constructs, which are based on labeled transition systems, are given. Provisions for backward error recovery are described that allow well-esta... View full abstract»

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  • Architectural support for debugging and monitoring real-time software

    Publication Year: 1989, Page(s):200 - 210
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (792 KB)

    A two-phase approach for nonintrusive debugging of real-time programs is outlined. The first phase involves monitoring the program and the second phase is concerned with replaying the program to get identical behavior. The first phase is concentrated on in this paper, and some of the difficulties in nonintrusive monitoring are highlighted. Architectural modifications that must be made to the targe... View full abstract»

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  • The rationale of an environment for real-time software

    Publication Year: 1989, Page(s):37 - 42
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (572 KB)

    Some core ideas that lead to the definition of an environment for real-time systems are discussed. It is explained how integration, flexibility, and validation support can be achieved by using a suitable formalism as a hidden underlying kernel for the environment. The kernel formal notation proposed (called environment relationship nets, or ER nets) is an extension of Petri nets where tokens are n... View full abstract»

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  • Queueing analysis in dynamic distributed real-time systems

    Publication Year: 1989, Page(s):162 - 166
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (288 KB)

    The effect of queueing on a dynamic distributed real-time system, in which jobs have hard deadline requirements, is studied. A job can be guaranteed to be completed before its deadline expires; it is rejected otherwise. An analytic model is presented to calculate the probability that an arbitrary arriving job will be guaranteed. An embedded Markov chain is first established, followed by a probabil... View full abstract»

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  • TPP-SO/P: a real-time operating system for distributed applications

    Publication Year: 1989, Page(s):44 - 50
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (280 KB)

    The authors present a real-time, multitasking, multiuser operating system for a processor board based on the Intel microprocessor iAPX 286. Protection mechanisms and task management features of the processor are noted. An extended CHILL concurrency environment is implemented to provide facilities for real-time software development. Memory management, system interface, debugging, fault treatment, i... View full abstract»

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  • Adaptive real-time file handling in local area networks

    Publication Year: 1989, Page(s):153 - 161
    Cited by:  Papers (2)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (672 KB)

    Current and future needs in building adaptive real-time systems are analyzed and a series of design requirements for their hardware/interconnection, operating system, and application levels are formulated. The major features of the corresponding integrated system design model are described. On the operating system level, services are rendered by the DRAGON SLAYER distributed operating system to bo... View full abstract»

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  • The design of Tri-D real-time computer systems

    Publication Year: 1989, Page(s):84 - 92
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (620 KB)

    A family of designs are presented for high-performance real-time computers based on novel real-time computer design principles. These design principles are founded upon a three-dimensional measure that defines system performance in three critical dimensions of real-time computing: raw computational speed, high-speed interrupt handling, and high input/output throughput. High three-dimensional perfo... View full abstract»

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  • Routing messages with release time and deadline constraints

    Publication Year: 1989, Page(s):168 - 177
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (768 KB)

    The problem of deciding if a set of real-time messages can be transmitted in a unidirectional ring network with m>1 nodes is considered. Complexity results are given for various restrictions on the four parameters associated with each message: origin node, destination node, release time and deadline. For nonpreemptive transmission, it is shown that the problem is solvable in polynomial... View full abstract»

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  • A priori execution time analysis for parallel processes

    Publication Year: 1989, Page(s):62 - 65
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (312 KB)

    A method of knowing a priori the time required by parallel processes to complete their execution is described, which allows for the automatic estimation of an upper bound for a task's execution time. The method is discussed within the framework of the high-level real-time programming language Pearl. Several language extensions are defined to enable the execution-time estimations for all language c... View full abstract»

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  • New approaches for distributed industrial process control systems aimed to cope with strict time constraints

    Publication Year: 1989, Page(s):130 - 136
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (660 KB)

    Four approaches aimed to cope with strict timing constraints as encountered in industrial process control applications are presented. For each node in a distributed system, an asymmetrical two-processor architecture is used that is capable of guaranteeing response times. One processor in each node is dedicated to the kernel of a real-time operating system. Its three reaction levels are constructiv... View full abstract»

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  • Computational reflection in RT systems

    Publication Year: 1989, Page(s):31 - 36
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (480 KB)

    Computational reflection is the activity performed by a computational system when doing computation about its own computation. This concept is highly relevant in real-time (RT) nonstopping systems where the distinction between host and target vanishes. The authors present a model where the system is represented as a network of objects and relations. Objects have multiple representations partitione... View full abstract»

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  • TRIO, a logic formalism for the specification of real-time systems

    Publication Year: 1989, Page(s):26 - 30
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (408 KB)

    Results are presented of a research project aimed at the definition of an executable logic formalism for the specification of real-time systems. The logic language TRIO allows the specifier to express formally and quantitatively the temporal properties of the specified systems. A formal definition of execution of specifications in terms of generation of interpretations for the corresponding formul... View full abstract»

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  • Combining different granularity of concurrency for real time applications

    Publication Year: 1989, Page(s):11 - 17
    Cited by:  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (560 KB)

    The authors investigate how adequate tools for concurrent programming may improve the development of real-time applications. First, any such application can be decomposed as a set of cooperating processes. Secondly, if adequate architectural support is available, further parallelism of execution can be achieved on critical parts of the program. The model of concurrency, and the granularity of deco... View full abstract»

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  • Different approaches to real-time application allocation to a multiprocessor system

    Publication Year: 1989, Page(s):18 - 23
    Cited by:  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (380 KB)

    Existing approaches to the design of real-time application assignment algorithms are classified and evaluated. The different approaches considered are: one described by T.L. Casavant and J.G. Kuhl (IEEE Trans. Soft. Eng., vol.14, no.2, 1988), load balancing, interprocessor communication minimization, fixed allocation first, those that use precedence consideration methods, and constraint allocation... View full abstract»

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  • Real-time reconfiguration of two-dimensional VLSI arrays

    Publication Year: 1989, Page(s):217 - 225
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (532 KB)

    The extension of index mapping to the reconfiguration of two-dimensional VLSI arrays in real time is presented. Index mapping is implemented by a two-operator technique which assigns to a faulty cell a unique fault free space. This process is accomplished by a decentralized parallel approach which finds the appropriate of deformation for the recomputation of the indices and their mapping. It is pr... View full abstract»

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  • Integration of a sensor in robot motion control with fast reactions parallel processed in real time

    Publication Year: 1989, Page(s):124 - 129
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (360 KB)

    A method is described for the implementation of a sensor control in parallel to a simple robot motion control. This method offers great modularity by decentralization, fast reactions in real-time by parallel computing of the sensor data, implementability of various, application-specific control algorithms for sensor data, a relatively slow communication with a robot motion control on the Cartesian... View full abstract»

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  • On using the Spring kernel to support real-time AI applications

    Publication Year: 1989, Page(s):51 - 60
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (816 KB)

    The authors discuss where current operating-system paradigms for real-time systems are inadequate and then present a novel operating-system paradigm. Some of the details of how the Spring kernel supports this novel paradigm are discussed. Immediate research goals for real-time artificial intelligence (RTAI) applications and the additional requirements and capabilities needed to support such demand... View full abstract»

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  • The ART testbed: towards a predictable and reliable distributed real-time system

    Publication Year: 1989, Page(s):211 - 216
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (492 KB)

    An overview of the software components of the Advanced Real-time Technology (ART) system is given. In particular, the integrated time-driven scheduling model which provides predictability, flexibility, and ease of modification for both hard and soft real-time activities, the ARTS kernel including real-time object and thread support, and its basic performance are described. Also included is a summa... View full abstract»

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  • Real time properties of LANs according to the Manufacturing Automation Protocol (MAP)

    Publication Year: 1989, Page(s):146 - 150
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (260 KB)

    The author reports on an evaluation of real-time properties of Manufacturing Automation Protocol (MAP) networks through analytical considerations which are then compared to measurement data. Measurements were made on a MAP 2.1 network that consists of 5 nodes based on the Motorola VME-bus MAP-controller MVME 372. This implementation has a complete logical link control layer (LLC-layer) and MAP-lay... View full abstract»

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