Concurrency and communication are two of the key features of distributed systems. These features can make systematic testing of distributed systems a complex task. A major problem is the explosion of the test space be...
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Concurrency and communication are two of the key features of distributed systems. These features can make systematic testing of distributed systems a complex task. A major problem is the explosion of the test space because of the potential for arbitrary interference of concurrent threads. This paper describes an approach for systematic testing of such systems in an object-oriented context. We use statecharts for system specification, and model the system behaviour as event-sequences. A test case, therefore, is primarily an event-sequence with concurrent threads represented as interleaving events. Communication-states with associated events represent communication between objects. The test-space explosion is controlled by an extension to Chow's (1978) algorithm for generating test sequences for finite state machines. The number of test sequences we require is O(n/sup 2/), where n is the sum of all events in all concurrent statecharts.
In this paper we address the decomposition problem of electromyographic signals (EMG) and we present a new idea for the decomposition approach introducing the time-scale phase representation. Considering the nature of...
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In this paper we address the decomposition problem of electromyographic signals (EMG) and we present a new idea for the decomposition approach introducing the time-scale phase representation. Considering the nature of EMG signals, a special set of nonorthogonal conjugated basis functions is used to perform the time-scale analysis. Mapping the modified signal phase into the time-scale phase plane is applied. Its minimization leads towards a very good time localization of individual superimposed signal components.
Object-orientation has rapidly become accepted as the preferred paradigm for large scale system design. There is considerable literature describing approaches to object-oriented design and implementation. However disc...
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Object-orientation has rapidly become accepted as the preferred paradigm for large scale system design. There is considerable literature describing approaches to object-oriented design and implementation. However discussion of testing in an object-oriented environment has been conspicuous by its absence. At first sight it appears that decomposition of a system into a potentially large number of information-hiding classes greatly increases the cost of testing. However in this paper we show that by taking an object-oriented approach to testing, and the inclusion of appropriate tools in the development environment, testing time can be greatly reduced and special purpose test code can be virtually eliminated.
This paper deals with methods of automated memory synthesis for Custom Computing Machines (CCMs). We focus the presentation on the synthesis of interleaved memory systems, which provide the quickest access to data at ...
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This paper deals with methods of automated memory synthesis for Custom Computing Machines (CCMs). We focus the presentation on the synthesis of interleaved memory systems, which provide the quickest access to data at the cost of more parallel hardware. The synthesis of an interleaved memory system starts with the analysis of data access patterns in the algorithm, from which a number of possible storage schemes is derived. The storage scheme defines how the array elements can be distributed among different memory banks. The best storage scheme is then chosen according to a complex metric of cost and performance of the required memory system. This metric involves the schedule length of operations, the type and number of required memory chips, the cost and delay of address generation and the interconnection network. Results of our experiments demonstrate that the developed methods are capable to automatically synthesise storage schemes and interleaved memory systems, which are the same or better than those previously conceived by an experienced hardware designer.
In order to realize multimedia applications such as VOD (Video-on-Demand) over highspeed networks, suitable QoS (Quality of Service) of the continuous media such as audio and video have to be guaranteed in accordance ...
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In order to realize multimedia applications such as VOD (Video-on-Demand) over highspeed networks, suitable QoS (Quality of Service) of the continuous media such as audio and video have to be guaranteed in accordance with users' requirements, available computing and network resources during the service session. In this paper, we introduce the Media Coordinate System which provides end-to-end QoS guarantee and negotiation functions consistently from the application through network layers. Within these QoS control functions we introduce a packet rate control method to reduce the packet loss, and a frame rate control method to maintain the frame rate at a constant under the dynamic load conditions. We implemented the media coordinate system as a prototyped Video-on-Demand system and evaluated the performance of these control functions. Through these performance evaluations, we could justify the usefulness of our suggested media coordinate system.
作者：
J. XuD.L. ParnasYork University
Department of Computer Science Toronto Ontario M3J 1P3 Canada McMaster University
Department of Computing and Software Faculty of Engineering Hamilton Ontario L8S 4K1 Canada
Builders of real-time systems often use priority scheduling in their systems without considering alternatives. This paper examines one alternative, pre-run-time scheduling, and show that when it can be applied it has ...
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Builders of real-time systems often use priority scheduling in their systems without considering alternatives. This paper examines one alternative, pre-run-time scheduling, and show that when it can be applied it has significant advantages when compared to priority scheduling schemes.
作者：
Frank HoudekKurt SchneiderEva WieserDaimler-Benz AG
Research and Technology P.O. Box 23 60 89013 Ulm Germany and University of Ulm Faculty of Computer Science Dept. Software Engineering 89069 Ulm Germany Daimler-Benz AG
Research and Technology P.O. Box 23 60 89013 Ulm Germany
In an attempt to propose a robust method for understanding natural language (NL) interface commands, a scheme is proposed that infers intentions from an indirect speech-act that does not express users' real intent...
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In an attempt to propose a robust method for understanding natural language (NL) interface commands, a scheme is proposed that infers intentions from an indirect speech-act that does not express users' real intentions explicitly. This method classifies the real intentions of the indirect speech-act into: 1) refusal;2) reversal;3) restriction;4) benefit;and 5) disability. Further, concepts are abstracted for operations, e.g., displaying, moving, and deleting information systems;and constructing the operation knowledge base. This knowledge based comprises operational concepts and the relationships between them. These relationships are assigned the foregoing classifications for intentions. In addition, we construct the knowledge base of objects for the target of operations, e.g., files, figures, strings. This knowledge base contains the relationships: a) antonym;b) exclusive;c) part-of, between the objects;and uses these relations to infer the transitions between the objects. An algorithm is the proposed to infer concepts for operations and concepts for target objects of operations that may represent the user's actual intentions. This proposal scheme was tested with requests on UNIX and a commercially available Japanese Word Processor. The system successfully inferred the intentions for approximately 80 percent of the user's indirect speech-act.
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