Traditional real-timecomputing concepts and techniques are focused on static, synchronous, relatively small-scale, mostly centralized, device-level subsystems. Many real-time systems, particularly distributed ones, a...
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ISBN:
(纸本)076952124X
Traditional real-timecomputing concepts and techniques are focused on static, synchronous, relatively small-scale, mostly centralized, device-level subsystems. Many real-time systems, particularly distributed ones, are relatively large-scale, above the device level, and at least partially dynamic and asynchronous. We call such systems "mesosynchronous." For example, mesosynchronous systems often are found in military surveillance and force projection platforms, and in network-centric warfare (plus civilian domains). Hence the lives of both friends and foes depend on the timeliness properties of such systems being dependably acceptable according to application- and situation-specific criteria. The real-time research community has historically failed to perceive and appreciate this - admittedly difficult and domain-knowledge intensive - problem, especially for end-to-end timeliness in distributed mesosynchronous real-time systems.
For distributedreal-time systems, adequate profiling tools are exceedingly rare. The sheer variety and low-level nature of these systems impede the adoption of standard, general-purpose tools for performance analysis...
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ISBN:
(纸本)076952561X
For distributedreal-time systems, adequate profiling tools are exceedingly rare. The sheer variety and low-level nature of these systems impede the adoption of standard, general-purpose tools for performance analysis and visualization. Although much research has been devoted to profiling parallel clusters and supercomputers, the literature virtually ignores the real-time domain. Correspondingly, a handful of commercial tools is available for profiling realtime software, but they invariably make a single-node assumption and are unable to cope with distributed environments. We examine the state of performance analysis and discuss why profilers are conspicuously absent in the field of distributedreal-time systems. We then explore how developers of these systems could benefit from graphical profiling tools with automatic instrumentation and data collection. Toward that end, we demonstrate the prototype of a performance visualization tool called "Bacara," the second addition to our suite of tools for Visual Analysis of distributedreal-time systems, or VADR (va'dar).
object-oriented (OO) modeling languages, tools, and methods more and more attract the interest of embedded (real-time) system developers. This is especially true if embedded (real-time) system software has to cooperat...
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object-oriented (OO) modeling languages, tools, and methods more and more attract the interest of embedded (real-time) system developers. This is especially true if embedded (real-time) system software has to cooperate with interactive multimedia software, as it is more and more the case in automotive systems. It is still an open question whether and how the standard OO modeling language UML and its accompanying tools have to be adapted to the regarded application domain. This paper evaluates the development of a rapid prototype for an air condition controller with the popular CASE tool Rational Rose/RT(R). We point out some weaknesses of the presented solution and propose an extension to Rose/RT(R), which overcomes the weaknesses by combining Rose/RT's UML dialect with data flow equations.
Numerous technical and life cycle cost consideration trends have led to a large increase in the use of commercial, off the shelf (COTS) computing and networking infrastructure in military command and control (C2) appl...
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ISBN:
(纸本)076951300X
Numerous technical and life cycle cost consideration trends have led to a large increase in the use of commercial, off the shelf (COTS) computing and networking infrastructure in military command and control (C2) applications. objectoriented (OO) real-time middleware, such as RT CORBA, provides the capabilities required for domain specific services and applications. However, it is unproven whether such commercial technologies can achieve the hard realtime performance required by many C2 system. Our study reveals that DOC middleware is suitable for some real-time applications when appropriately coupled with operating system and network protocol quality of service (QoS) mechanisms areas in which further progress is still needed.
Dependability of complex systems is a critical system-level issue, which is still insufficiently tackled today. We propose here the adoption of an aggressive model-driven development paradigm (AMDD) to adequately capt...
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ISBN:
(纸本)076952124X
Dependability of complex systems is a critical system-level issue, which is still insufficiently tackled today. We propose here the adoption of an aggressive model-driven development paradigm (AMDD) to adequately capture globally-scoped issues like interoperability and compatibility. AMDD moves most of the recurring problems of compatibility and consistency of a system's design, implementation and evolution from the coding and integration level to the modelling level. In particular it enables an economical treatment of cross-system issues. This approach has proven useful already for the design, realization and test of complex distributed applications. In this paper we discuss the potential and benefits of AMDD and present examples where it is already adopted.
An open distributed control system (DCS), which consists of many devices and an open network interconnecting them, is now used in many automation areas. For assuring the control performance under the heavy traffic on ...
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ISBN:
(纸本)0769510892
An open distributed control system (DCS), which consists of many devices and an open network interconnecting them, is now used in many automation areas. For assuring the control performance under the heavy traffic on the network, the simulation of a DCS is strongly needed. For this purpose, we propose an object-oriented design pattern approach as a uniform, efficient and accurate method of modeling and simulating a DCS. Four design patterns are newly proposed. Device-Constructor and Composite-Device-Constructor patterns describe classes and mechanisms for uniformly structuring device models composed of many kinds of sensors and actuators. Statechart pattern defines classes and the state-transition execution mechanism for realizing the behavior of sensors and actuators in a device. While Event-Chain pattern defines classes and the event dispatching mechanism among sensors and actuators intra-device and inter-device. The systematic implementation procedures from these patterns to the executable Java code of the DCS simulation model are also discussed. Finally, the effectiveness of our approach was proved by developing the Java-based DCS modeler and simulator used in building automation area.
The growing complexity of today's embedded real-time systems demands new methods and tools in order to manage the problems of design, analysis, integration and validation of complex systems. This paper describes a...
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ISBN:
(纸本)0769523560
The growing complexity of today's embedded real-time systems demands new methods and tools in order to manage the problems of design, analysis, integration and validation of complex systems. This paper describes an object-oriented platform-based design process for real-time embedded systems. The proposed approach promotes a smooth transition from high-level UML specification to implementation, which is composed by hardware and software components. The transition from higher to lower abstraction levels is facilitated by the use of an OO real-time API, whose underlying facilities can be optimized according to the application needs and selected platform. An integrated toolset is used to support the intermediate steps of the design process. In order to illustrate the proposed approach and related toolset the design of an embedded real-time automation system for an "intelligent" wheelchair is presented.
Code generation from hybrid system models is a promising approach to producing reliable embedded systems. This approach presents new challenges as the precise semantics of the model are hard to capture in the code. A ...
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ISBN:
(纸本)0769523560
Code generation from hybrid system models is a promising approach to producing reliable embedded systems. This approach presents new challenges as the precise semantics of the model are hard to capture in the code. A framework for generating code was introduced for single threaded/processor environments. Here, we extend it by considering code generation for distributed environments. We also define criteria for faithful implementation of the model. To this end, we define faulty and missed transitions. For preventing faulty transitions, we build on the idea of instrumentation we have developed for sound simulation of hybrid systems. Finally, we present sufficient conditions to avoid missed transitions and provide examples.
Static cache analysis for data allocated on the heap is practically impossible for standard data caches. We propose a distinct object cache for heap allocated data. The cache is highly associative to track symbolic ob...
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The paper explores aspects concerning system-level specification, modelling and simulation of realtime embedded system. By means of case studies, we investigate how objectoriented methodologies, and in particular UM...
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