By Topic

Second Workshop on Parallel and Distributed Real-Time Systems

28-29 April 1994

Filter Results

Displaying Results 1 - 25 of 32
  • Second Workshop on Parallel and Distributed Real-Time Systems

    Publication Year: 1994
    Request permission for commercial reuse | PDF file iconPDF (22 KB)
    Freely Available from IEEE
  • A convergence function for clock synchronization protocols

    Publication Year: 1994, Page(s):9 - 16
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (644 KB)

    A distributed fault-tolerant Convergence Function (CF) is proposed to resynchronize clocks with high precision. The CF can be used in conjunction with drift corrections which significantly increases the period between resynchronizations. This is important when clock drifts are large, because clock synchronization overhead then becomes intolerable. Clock differences are disseminated by a reliable m... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The advanced distributed ramp metering system (ARMS)

    Publication Year: 1994, Page(s):17 - 22
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (536 KB)

    Ramp metering is an important technique to effectively utilize the freeway capacity by regulating the traffic flow of freeway entrance ramps. In this extended abstract, we discuss the outline of the free flow control algorithm of the Advanced distributed Ramp Metering System, ARMS, for the real-time control of freeway ramp metering systems. ARMS consists of three levels of control algorithms integ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • TaskPair-scheduling: an approach for dynamic real-time systems

    Publication Year: 1994, Page(s):24 - 31
    Cited by:  Papers (13)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (576 KB)

    In this paper an on-line scheduling approach called TaskPair-Scheduling is presented which merges the concepts of guaranteeing (an activity) and exception handling (due to time-outs) such that the guarantee may enclose the execution of the exception handler. An on-line scheduling algorithm is shown which plans guaranteed try-except constructs as a pair of tasks (MainTask, ExceptTask) by considerin... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Issues in integrating reusable Ada 9X objects into distributed real-time systems

    Publication Year: 1994, Page(s):150 - 153
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (284 KB)

    A rapid prototyping tool for distributed real-time systems relies on a repository of reusable software components (or objects) to support application development. The goal is to quickly generate systems that meet hard real-time constraints. The components in the repository must be retrievable, easily reusable, and possess attributes that facilitate scheduling analysis. Components written in Ada 9X... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Real-time issues in distributed multimedia systems

    Publication Year: 1994, Page(s):88 - 97
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (628 KB)

    The fundamental characteristics of multimedia systems is that they incorporate continuous media, such as voice, video, and animated graphics. This implies the need for multimedia systems to handle data with strict timing requirements and at high rate. This article discusses important real-time issues in distributed multimedia systems including media synchronization, operating system support for co... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Use of concurrency enhancement in off-line schedule construction

    Publication Year: 1994, Page(s):32 - 37
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (552 KB)

    To improve the performance of programs composed of abstract data types (ADTs), a parallel execution model is used to exploit concurrency at the method level. Typically, an ADT instance is used to manage more than one variable, and there may be contention for getting access to the ADT instance if multiple variables need to be accessed concurrently. To resolve the contention, the ADT instance is clo... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Representing system behavior in design and analysis of large complex real-time systems

    Publication Year: 1994, Page(s):154 - 159
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (508 KB)

    This paper summarizes several existing techniques for representing system behavior and describes the key features of an advanced approach for capturing behavior for a large, complex, real-time, computer-based system within a multi-domain system design capture and analysis methodology. Within this advanced approach for capturing system behavior three key aspects of representing complex system behav... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Modification and adjustment of real-time tasks with rate monotonic scheduling algorithm

    Publication Year: 1994, Page(s):98 - 103
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (460 KB)

    Many researches on dynamic scheduling techniques for real-time systems have focused on changes in the number of tasks. We propose a dynamic real-time scheduling technique, called MART, in which it is also possible to change task characteristics. When MART is used in systems where task characteristics need to be and can be modified, it enables the system to be adaptable to changing environments dyn... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Performance analysis of a neural network based scheduling algorithm

    Publication Year: 1994, Page(s):38 - 42
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (408 KB)

    We analyse the use of artificial neural networks (ANNs) to approximate solving scheduling problems. It is well established that the ANNs main advantage is the small amount of time they take to find an approximate solution, but a question arises: what about the optimality of the obtained solution? A considerable variety of work has been carried out on this subject but, unfortunately, the majority o... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Supporting distributed real-time objects

    Publication Year: 1994, Page(s):138 - 143
    Cited by:  Papers (2)  |  Patents (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (488 KB)

    This paper describes a distributed environment for real-time applications. The context of this research is Open Distributed Processing (ODP). It is the stringent timeliness and performance requirements of real-time applications that are the primary source of problems posed by real-time applications. The services provided by existing distributed system environments predate the present concerns of r... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Partitioning complex real-time systems for distribution

    Publication Year: 1994, Page(s):160 - 164
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (492 KB)

    A substantial amount of time and money has been invested in large complex reactive systems. The size of these legacy systems often puts an organization into the position of having too much invested to completely redesign and reimplement the product. Therefore, methods for transitioning these systems to more modern architectures must be synthesized, after the fact, from the existing programming art... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The integration of control and dataflow structures in distributed hard real-time systems

    Publication Year: 1994, Page(s):104 - 107
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (360 KB)

    The control structure of many real-time applications are naturally described by state machines. However the state transitions of these machines are governed not only by the state of the system and the occurrence of events, but also by their time of occurrence. The control structure of a real-time system determines what computation to perform and the set of timing constraints in effect at all times... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Task and resource assignment in distributed real-time systems

    Publication Year: 1994, Page(s):43 - 51
    Cited by:  Papers (7)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (676 KB)

    In this paper, we propose an efficient algorithm to statically assign tasks and logical resources to the processors, taking into account the blocking times due to resource contention. We formulate the assignment problem using an assignment graph where the weights on the edges of the graph represent the desirability of assigning the tasks (connected by the edges) to the processors. These weights ar... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A special-purpose parallel system for predictable real-time systems

    Publication Year: 1994, Page(s):176 - 181
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (464 KB)

    Parallel systems usually increase the complexity of evaluating the program execution time, so as to verify timing constraints into real-time environments. For this reason, the approach described in this paper is based on a massively parallel architecture using VLSI to implement in a fine-grain mode the data-flow paradigm. The system employs the static data-flow execution model that does not need t... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Compound service scheduling with run-time adaptation in real-time multiprocessor distributed systems

    Publication Year: 1994, Page(s):119 - 124
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (568 KB)

    A compound service comprising one or more task, occurring unpredictably and constrained by a single deadline may not be successfully scheduled. A goal for managing such services as to maximize the success ratio SR, i.e. the percentage of successfully scheduled services. This paper describes an adaptive run-time scheduling method for improving the SR of a real-time distributed system. Simulation is... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Empirical evaluation of weighted and prioritized static scheduling heuristics for real-time multiprocessing

    Publication Year: 1994, Page(s):58 - 63
    Cited by:  Papers (1)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (568 KB)

    Suboptimal solutions to the NP-complete problem of task scheduling in a multiprocessing system are achievable with the aid of heuristic methods. Static scheduling heuristics for real-time multiprocessing systems are typically based on existing algorithms developed for non-real-time systems. Unfortunately this approach results in the real-rime heuristics inheriting the deficiencies of the non-real-... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Hardware support for controlled interaction of guaranteed and best-effort communication

    Publication Year: 1994, Page(s):188 - 193
    Cited by:  Papers (8)  |  Patents (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (412 KB)

    Real-time communication typically consists of guaranteed packets that must satisfy their delivery deadlines and best-effort packets that can tolerate occasional deadline misses for improved average latency. This paper presents hardware techniques for supporting the coexistence of these two traffic classes in real-time point-to-point networks. A careful selection of routing and switching techniques... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Adjustable flow control filters and reflective memories as support for distributed real-time systems

    Publication Year: 1994, Page(s):2 - 8
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (548 KB)

    Distributed real-time systems are difficult to construct such that the system behaves predictably. In addition, many of these systems must operate in complex and uncertain environments. We discuss two main ideas for moving distributed real-time systems towards predictability: adjustable flow control filters and reflective memories. Both of these are hardware based solutions that should be exploite... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • An object-oriented methodology for the design of control software for flexible manufacturing systems

    Publication Year: 1994, Page(s):144 - 149
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (484 KB)

    We describe here a systematic method for the design and modeling of flexible manufacturing systems, using object-oriented concepts and Petri nets. We first define the system components in terms of an object model consisting of hierarchical sets of classes and associations. Then, we model the dynamic aspects of the system using statecharts, including exceptions and abnormal behavior. As a third ste... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Simulation of distributed real-time transactions

    Publication Year: 1994, Page(s):82 - 87
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (444 KB)

    Distributed nested objects are considered as the building blocks for distributed real-time systems. Objects are stored in memory. Objects can be related in two ways: (1) syntactically: they have a common object from which they are invoked and (2) time-wise: the actions on the objects always occur at the same moments. The consistency of a set of related objects is assured with concurrency control a... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Synchronous/anytime programming for distributed reactive systems

    Publication Year: 1994, Page(s):131 - 136
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (372 KB)

    In this paper, we first propose a mixed synchronous/asynchronous programming model for distributed reactive systems. This model is built around a set of synchronous reactive kernels, written in Esterel synchronous language, each of them controlling a set of asynchronous and time-consuming tasks, through a set of tasks control directives. In this paper, we focus on protocols allowing the implementa... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Implementation of a priority forwarding router chip for real-time interconnection networks

    Publication Year: 1994, Page(s):166 - 175
    Cited by:  Papers (3)  |  Patents (8)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (704 KB)

    A single-chip VLSI implementation of a 4 by 4 prioritized router for multistage real-time interconnection networks is presented. The chip employs packet switching and facilitates 32-bit priority arbitration by means of a priority forwarding scheme that prevents priority inversion and which provides accurate priority control in a network. The packets are of fixed size, having three 38-bit segments:... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Modeling priority schemes with timed Petri nets

    Publication Year: 1994, Page(s):110 - 118
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (628 KB)

    The applicability of well known medium access control (MAC) protocols for real time systems is of great interest for the development of suitable communication schemes in this field. This paper introduces models for the priority schemes of well known token protocols, since they provide deterministic behaviour and therefore guarantee time constraints. Deterministic and Stochastic Petri Nets (DSPN) a... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Real-time optimization of distributed load balancing

    Publication Year: 1994, Page(s):52 - 57
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (468 KB)

    The problem of optimizing the balancing of processing load originating at the various sites of a bus-interconnected set of heterogeneous processors is examined. The distributed load is assumed to be arbitrarily divisible with no particular affinity to any of the processing sites. Minimization of processing completion time is the objective of load redistribution via the limited communication capaci... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.