The data structures for general searching problems are studied. One of the transformations is discussed which is used for converting solutions of simple searching problems to solutions of more complex ones. Conditions...
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The data structures for general searching problems are studied. One of the transformations is discussed which is used for converting solutions of simple searching problems to solutions of more complex ones. Conditions of applicability of this transformation are specified and its correctness is proved by using the Alphard form mechanism.
To satisfy the requirements of real time applications, three techniques can be employed, involving either real time clock, programmable timers, or constrained programming. Designer of microcomputers will have the maxi...
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To satisfy the requirements of real time applications, three techniques can be employed, involving either real time clock, programmable timers, or constrained programming. Designer of microcomputers will have the maximum flexibility and power if a multitask executive system is available. In this paper, a nonpreemptive pseudo-asynchronous scheduler is adopted in a multitask system and implemented on a MCS6502 microcomputer. The programming example considered shows a number of superior characteristics absent in the constrained programming implementation. The storage overhead of the multitask approach can only be justified when the number of concurrent running processes is large.
The nature and value of investment in large Mathematical programmingsystems is assessed and an attempt is made to determine how it may be best used in the solution of current problems. Current MPS technology and deco...
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The nature and value of investment in large Mathematical programmingsystems is assessed and an attempt is made to determine how it may be best used in the solution of current problems. Current MPS technology and decomposition techniques are briefly surveyed and discussed. A detailed consideration is given to generalized upper bounding techniques and to mixed integer models. the DATAFORM data management system is explained. It is concluded that the really important technical areas to be improved now are data management and system control. It is suggested that a new type of organization be set up to continue the development of technology and provide uniform service to any legitimate client. The service organization should be nonprofit and not dependent on its direct revenues for funding.
We consider the problem of proving correctness properties for concurrent systems with features such as higher-order communication and dynamic resource generation. As examples we consider operational models of security...
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ISBN:
(纸本)0818682558
We consider the problem of proving correctness properties for concurrent systems with features such as higher-order communication and dynamic resource generation. As examples we consider operational models of security and authentication protocols based on the higher-order pi-calculus. Key features such as nonces/time stamps, encryption/decryption, and key generation are modelled using channel name generation and second-order process communication. A temporal logic based on the modal mu-calculus is used to express secrecy and authenticity. Extensions include function space constructions to deal with process input and output. Contravariant recursion can be dealt with in two different ways, of which one, an iterative solution, is discussed in the paper. We propose a predicate of trust in a monotonically increasing set of channels as an example, and establish structural decomposition principles for this predicate for concurrent composition and local channel declaration. On this basis a type system for trust inference can be derived quite easily.
Evaluation of a computer system is an art which relies upon an analysis of pertinent data. A methodology is described which allows data relating to the behavior of a system to be collected by software without introduc...
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Evaluation of a computer system is an art which relies upon an analysis of pertinent data. A methodology is described which allows data relating to the behavior of a system to be collected by software without introducing perturbation. Simulation techniques which allow the system to be represented by a real operating system in a simulated environment, permit performance estimates of simulated hardware configurations under the influence of bench mark programs.
A new method for the control of a multiprogrammed virtual memory computer system is proposed. A mathematical model solved by decomposition shows that the method avoids thrashing. Simulation experiments are used to tes...
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A new method for the control of a multiprogrammed virtual memory computer system is proposed. A mathematical model solved by decomposition shows that the method avoids thrashing. Simulation experiments are used to test the robustness of the predictions of the mathematical model when certain simplifying assumptions are relaxed and when a slightly simpler control technique based on the same principle is used. Comparisons are given with the case where an ″optimal″ control is used and with that with no control.
Allocation of paged memory in a multiprogramming environment is considered. Based on uniprogramming studies, such as statistical observations of actual programs as well as primitive program models, a memory space shar...
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Allocation of paged memory in a multiprogramming environment is considered. Based on uniprogramming studies, such as statistical observations of actual programs as well as primitive program models, a memory space sharing algorithm is constructed which selects a program to lose a page when a new page is demanded.
This paper presents new results on an approach for solving satisfiability problems (SAT), i.e. creating a logic circuit that is specialized to solve each problem instance on Field Programmable Gate Array's (FPGAs)...
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ISBN:
(纸本)0818682558
This paper presents new results on an approach for solving satisfiability problems (SAT), i.e. creating a logic circuit that is specialized to solve each problem instance on Field Programmable Gate Array's (FPGAs). This approach becomes feasible due to the recent advances in FPGAs and high-level logic synthesis. In this approach, each SAT problem is automatically analyzed and implemented on FPCAs. We have developed an algorithm,which is suitable for implementing on a logic circuit. This algorithm is equivalent to the Davis-Putnam procedure with a powerful dynamic variable ordering heuristic. The algorithm does not have a large memory structure like a stack, thus sequential accesses to the memory do not become a bottleneck ill algorithm execution. Simulation results show that this method can solve a hard random 3-SAT problem with 400 variables within 20 minutes at a clock rate of 1MHz.
A new solution for the two-processor scheduling problem is proposed which predominantly employs the Hu algorithm. Furthermore, special task dependency structures are introduced which essentially are composed of trees ...
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A new solution for the two-processor scheduling problem is proposed which predominantly employs the Hu algorithm. Furthermore, special task dependency structures are introduced which essentially are composed of trees and anti-trees, and include the structure of nested DO-loops. It is shown that the application of the Hu algorithm yields optimal schedules for an arbitrary number of processors.
This paper discusses actual software reliability data obtained in an online real time environment. The measures used are the reliability function R(t) and the mean time between software errors MTBSE. How to measure th...
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This paper discusses actual software reliability data obtained in an online real time environment. The measures used are the reliability function R(t) and the mean time between software errors MTBSE. How to measure the operational data of R(t) or MTBSE and to analyze the measurement results are described, presenting collected reliability data. Some quantitative models are proposed which can be used to measure, manage and predict the level of perfection of software during the test stage.
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