In this paper, a centralized deadlock detection algorithm with multiple outstanding requests (CDDMOR) is proposed for use in distributed database systems and transaction-processing systems. This algorithm allows a pro...
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In this paper, a centralized deadlock detection algorithm with multiple outstanding requests (CDDMOR) is proposed for use in distributed database systems and transaction-processing systems. This algorithm allows a pro...
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In this paper, a centralized deadlock detection algorithm with multiple outstanding requests (CDDMOR) is proposed for use in distributed database systems and transaction-processing systems. This algorithm allows a process to request many resources simultaneously. While a centralized scheme is superior to a completely distributed scheme in terms of performance, a major problem of such a scheme is congestion. Therefore, an important extension to the basic CDDMOR, a partially distributed scheme, is proposed to alleviate the problem of congestion, as well as to take advantage of the result presented by several researchers that global (multisite) deadlocks are infrequent. It takes care of the local (single site) deadlocks without involving other sites and uses centralized deadlock detection only when there is a possibility of global deadlock.
A backtracking algorithm for AND-Parallelism and its implementation at the Abstract Machine level are presented: first, a class of AND-Parallelism models based on goal independence is defined, and a generalized versio...
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Air cushion vehicles (ACVs) have operated successfully on commercial routes for about twenty years. The routes are normally quite short; the craft are equipped with radar and radio navigation aids and maintain continu...
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Air cushion vehicles (ACVs) have operated successfully on commercial routes for about twenty years. The routes are normally quite short; the craft are equipped with radar and radio navigation aids and maintain continuous contact with their terminals. Navigation of these craft, therefore, does not present any unusual difficulty. The introduction of air cushion vehicles into military service, however, can present a very different picture, especially when external navigation aids are not available and the craft must navigate by dead reckoning. This paper considers the problems involved when navigating a high-speed air cushion vehicle by dead reckoning in conditions of poor visibility. A method is presented to assess the ACV's navigational capability under these circumstances. A figure of merit is used to determine the sensitivity of factors which affect navigation such as the range of visibility, point-to-point distance, speed, turning radius and accuracy of onboard equipment. The method provides simplistic but adequate answers and can be used effectively to compare the-capability and cost of alternative navigation concepts.
A ship design methodology is presented for developing hull forms that attain improved performance in both seakeeping and resistance. Contrary to traditional practice, the methodology starts with developing a seakeepin...
A ship design methodology is presented for developing hull forms that attain improved performance in both seakeeping and resistance. Contrary to traditional practice, the methodology starts with developing a seakeeping-optimized hull form without making concessions to other performance considerations, such as resistance. The seakeeping-optimized hull is then modified to improve other performance characteristics without degrading the seakeeping. Presented is a point-design example produced by this methodology. Merits of the methodology and the point design are assessed on the basis of theoretical calculations and model experiments. This methodology is an integral part of the Hull Form Design System (HFDS) being developed for computer-supported naval ship design. The modularized character of HFDS and its application to hull form development are discussed.
Causal source codes are defined. These include quantizers, delta modulators, differential pulse code modulators, and adaptive versions of these. Several types of causal codes are identified. For memoryless sources it ...
Causal source codes are defined. These include quantizers, delta modulators, differential pulse code modulators, and adaptive versions of these. Several types of causal codes are identified. For memoryless sources it is shown that the optimum performance attainable by causal codes can be achieved by memoryless codes or by time-sharing memoryless codes. This optimal performance can be evaluated straightforwardly.
This paper describes an evolving Arithmetic Design System (ADS) to support the quantitative evaluation of alternate number systems with respect to a given application and realization technology. A finite number system...
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We present a case study of the application of recently evolved structured VLSI design methodologies to the design and implementation of a simple VLSI quasi-serial inner product machine.
We present a case study of the application of recently evolved structured VLSI design methodologies to the design and implementation of a simple VLSI quasi-serial inner product machine.
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