In this paper, we describe a toolset for performance-based design and analysis of distributed realtime systems. The toolset is based on our design methodology, denoted Distributed Pipeline Scheduling [6, 7], that prov...
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ISBN:
(纸本)0818680164
In this paper, we describe a toolset for performance-based design and analysis of distributed realtime systems. The toolset is based on our design methodology, denoted Distributed Pipeline Scheduling [6, 7], that provides a set of rules that an engineer can follow to design near-optimal, distributed real-time systems with fully predictable, end-to-end performance properties. The methodology provides (I) models for capturing the application, resource, and system design specifications;(2) an analysis algorithm and figures of merit for evaluating a system design;and (3) allocation and scheduling algorithms for navigating the design space to find a near-optimal solution that meets application timing requirements and optimizes a set of system objectives (e.g., minimize total monetary cost of system and the number of resources used). The toolset, denoted the System engineering Workbench (SEW), aids system engineers to design, maintain, and upgrade distributed real-time systems by encapsulating the complexities of the methodology, while exporting a graphical user interface that is intuitive and easy to learn. The toolset has been applied to the design of several sonar;medical, and multimedia systems that have end-to-end timing requirements.
A growing awareness of the need to take into account social and contextual factors requirements engineering (RE) has led to expanded use of naturalistic inquiry (NI) methods, such as ethnography, for capturing relevan...
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A growing awareness of the need to take into account social and contextual factors requirements engineering (RE) has led to expanded use of naturalistic inquiry (NI) methods, such as ethnography, for capturing relevant data. There is little debate about the potential value of NI to the development of systems;however, most previous discussions have emphasized practical techniques and benefits. Less attention has been given to the ontological and epistemological commitments that a naturalistic research paradigm assume and the extent to which these assumptions conflict with those that pervade RE practice. In this paper we present the axioms that NI. In each case we address both the points of agreement and tension that arise when these axioms are compared with the implicit assumptions upon which RE practice and research methods are based. We illustrate the discussion with specific examples from published sources and our experience.
In May 39;96 a group of major hardware and software manufacturers jointly announced a set of guidelines forming an industry standard for a new class of devices called network computer (NC). The new industry standard...
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In May '96 a group of major hardware and software manufacturers jointly announced a set of guidelines forming an industry standard for a new class of devices called network computer (NC). The new industry standard-called the Network Computer Reference Profile 1 - is designed to accelerate the development of low-cost computing. The group of firms consisting of Apple, IBM, Oracle, Sun Microsystems and Netscape Communications unveiled plans to provide network computer operating software and a variety of NC hardware models by end of '96. The NC Reference Profile 1 considerably builds upon existing Internet and World Wide Web technology. This paper gives a brief overview of the goals pursued by the introduction of NC Reference Profile 1. It surveys the technologies employed for NCs and discusses their application and market potential in different environments.
We propose a model for quality-of-service (QoS) negotiation in building real-time services to meet both predictability and graceful degradation requirements. QoS negotiation is shown to (i) outperform conventional 3...
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ISBN:
(纸本)0818680164
We propose a model for quality-of-service (QoS) negotiation in building real-time services to meet both predictability and graceful degradation requirements. QoS negotiation is shown to (i) outperform conventional ''binary'' admission control schemes (either guaranteeing the required QoS or rejecting the service request), and (ii) achieve higher application-perceived system utility. We incorporated the proposed QoS-negotiation model into an example realtime middleware service, called RTPOOL, which manages a distributed pool of shared computing resources (processors) to guarantee timeliness QoS for real-time applications. The efficacy and power of QoS negotiation are demonstrated for an automated flight control system implemented on a network of PCs running RTPOOL. This system is used to fly an F-16 fighter aircraft modeled using the Aerial Combat (ACM) F-16 Flight Simulator. Experimental results indicate that QoS negotiation, while maintaining real-time guarantees, enables graceful QoS degradation under conditions in which traditional schedulability analysis and admission control schemes fail.
We present results from modeling and evaluating the JEWEL instrumentation system (IS), which is being used for runtime data collection from a distributed, real-time application. Our modeling and evaluation effort addr...
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Under the recent severe economic situation, computer system of companies have to produce new products or to supply new services flexibly to meet changing customers39; demands. To realize flexible computer system, th...
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Under the recent severe economic situation, computer system of companies have to produce new products or to supply new services flexibly to meet changing customers' demands. To realize flexible computer system, the system should be able to expand and modify its software as well as hardware rapidly. Moreover the companies have been tackling Business Process Re-engineering (BPR) to share various kinds of information among different departments, for quick response to the consumers' needs and cost reduction. Open ADS architecture that is a new control & information system architecture, is proposed to fulfill the flexibility of system. This paper introduces practical manufacturing system realized on the platform. These system are developed based on Hi-Cell concept that is defined as an assembly of autonomies called Homogeneous Max Intelligent Cells (HIC). In the system, techniques for resumption have been applied, and the effectiveness of it has been evidenced.
Reusing similar requirements fragments is among the promising ways to reduce elaboration time and increase requirements quality. This paper investigates the application of analogical reasoning techniques to complete p...
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Reusing similar requirements fragments is among the promising ways to reduce elaboration time and increase requirements quality. This paper investigates the application of analogical reasoning techniques to complete partial requirements specifications. A case base is assumed to be available;it contains requirements frameworks involving goals, constraints, objects, actions, and agents from systems already specified. We show how a rich requirements meta-model coupled with an expressive formal assertion language may increase the effectiveness of analogical reuse. An acquisition problem is first specified by the requirements engineer as a query formulated in the vocabulary of the specification fragments built so far. Source cases and partial mappings are found by query generalization followed by search through the case base. Once analogies have been confirmed, mappings are completed by use of relevance rules that distinguish in the formal assertions what is relevant to the analogy from what is irrelevant. Best analogies are then selected and extended in such a way that logical properties of the answers to the query may be verified, thus increasing confidence in the analogy. The approach is illustrated by analogical acquisition of specifications of a meeting scheduler in the KAOS goal-oriented specification language.
This paper describes a novel application of the MIST methodology to target detection in SAR images. specifically, a polarimetric whitening filter and a constant false alarm rate detector are used to preprocess a SAR i...
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In this paper, we describe a toolset for performance-based design and analysis of distributed real-time systems. The toolset is based on our design methodology, denoted Distributed Pipeline Scheduling [6,7], that prov...
详细信息
In this paper, we describe a toolset for performance-based design and analysis of distributed real-time systems. The toolset is based on our design methodology, denoted Distributed Pipeline Scheduling [6,7], that provides a set of rules that an engineer can follow to design near-optimal, distributed real-time systems with fully predictable, end-to-end performance properties. The methodology provides (1) models for capturing the application, resource, and system design specifications;(2) an analysis algorithm and figures of merit for evaluating a system design;and (3) allocation and scheduling algorithms for navigating the design space to find a near-optimal solution that meets application timing requirements and optimizes a set of system objectives (e.g., minimize total monetary cost of system and the number of resources used). The toolset, denoted the System engineering Workbench (SEW), aids system engineers to design, maintain, and upgrade distributed real-time systems by encapsulating the complexities of the methodology, while exporting a graphical user interface that is intuitive and easy to learn. The toolset has been applied to the design of several sonar, medical, and multimedia systems that have end-to-end timing requirements.
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