MOS current-mode logic (MCML) is an appealing design style for high-speed circuit applications. The article introduces a method to design MCML circuits optimally using a mathematical programming approach. The techniqu...
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MOS current-mode logic (MCML) is an appealing design style for high-speed circuit applications. The article introduces a method to design MCML circuits optimally using a mathematical programming approach. The technique may be used to achieve a variety of design goals, such as minimum delay, minimum power consumption, and minimum power-delay product (PDP). A by-product of this technique is that it provides an acceptable estimation of various design figures, like delay, power dissipation, voltage swing, and DC bias values. We apply the technique to the design of two different topologies for MCML universal gates tuned for minimum delay and minimum PDP. Simulation results confirm the accuracy of the design with average error of 8.3% in calculated results. Both circuits are implemented in a standard 0.18 /spl mu/m CMOS technology.
Many attempts have been made to implement supervisors derived by synthesis procedures peculiar to the supervisory control theory (SCT), most adopting the event-based supervisory control paradigm. However, when conside...
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Many attempts have been made to implement supervisors derived by synthesis procedures peculiar to the supervisory control theory (SCT), most adopting the event-based supervisory control paradigm. However, when considering code generation schemata for programmable logic controllers (PLCs), hardware resources are limited and event tracking is hard to realize satisfactorily. Moreover, previous work has highlighted differences between the abstract model adopted by SCT and realistic process control situations. Inappropriate solutions to these issues may result in code generation schemata that produce unreliable PLC code. A generative programming approach for PLCs based on a dual paradigm, the state-based supervisory control paradigm, is investigated in this paper. Such an approach exhibits interesting properties. For instance, the maximum depth of the PLC stack as well as PLC cycle timing evaluations become possible. Furthermore, well-known code optimization techniques can be used to obtain more efficient code
It is effective to avoid falling into local optimums at the original stage of the computation that the knowledge of multi-optimum distribution state is introduced into general programming of the particle swarm movemen...
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ISBN:
(纸本)0780388127
It is effective to avoid falling into local optimums at the original stage of the computation that the knowledge of multi-optimum distribution state is introduced into general programming of the particle swarm movement in particle swarm optimization algorithm. But if the proportion factor of multi-optimum programming can not be dynamic adjusted in the optimization process, the performance of the algorithm is limited. In this paper, fuzzy logic was introduced into the process of multi-optimum dynamic programming, and a kind of particle swarm algorithm based on fuzzy logic and multi-optimum programming was put forward and simulated. Simulation results show that, the general convergence character of the algorithm derived in this paper has better performance than traditional PSO, fuzzy adaptive PSO and static multi-optimum programming PSO algorithm proposed by authors previously.
In this paper we apply integer programming (IF) based techniques to the problem of delay balancing in wave-pipelined circuits. The proposed approach considers delays, as well as fan-in and fan-out associated with ever...
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In this paper we apply integer programming (IF) based techniques to the problem of delay balancing in wave-pipelined circuits. The proposed approach considers delays, as well as fan-in and fan-out associated with every node in the circuit. After a weighted graph representation of the circuit is formed a node collapsing procedure is used to preprocess (reduce the size of) the system and to obtain the final formulation of the IF problem, which is solved by using a branch and bound heuristic to acquire a minimum delay in the circuit. We also compare the proposed technique with application - to the same problem - of a linear programming solver.
In this paper we give a short introduction to logic programming approach to knowledge representation and reasoning. The intention is to help the reader to develop a 'feel' for the field's history and some ...
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In this paper we give a short introduction to logic programming approach to knowledge representation and reasoning. The intention is to help the reader to develop a 'feel' for the field's history and some of its recent developments. The discussion is mainly limited to logic programs under the answer set semantics. For understanding of approaches to logic programming built on well-founded semantics, general theories of argumentation, abductive reasoning, etc., the reader is referred to other publications. (C) 2002 Elsevier Science B.V. All rights reserved.
We show how automated support can be provided for identifying refactoring opportunities, e.g., when an application's design should be refactored and which refactoring(s) in particular should be applied. Such suppo...
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We show how automated support can be provided for identifying refactoring opportunities, e.g., when an application's design should be refactored and which refactoring(s) in particular should be applied. Such support is achieved by using the technique of logic meta programming to detect so-called bad smells and by defining a framework that uses this information to propose adequate refactorings. We report on some initial but promising experiments that were applied using the proposed techniques.
As artificial intelligence techniques are maturing and being deployed in large applications, the problem of specifying control and reasoning strategies is regaining attention. Complex AI systems tend to comprise a sui...
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As artificial intelligence techniques are maturing and being deployed in large applications, the problem of specifying control and reasoning strategies is regaining attention. Complex AI systems tend to comprise a suite of modules, each of which is capable of solving a different aspect of the overall problem, and each of which may incorporate a different reasoning paradigm. The orchestration of such heterogeneous problem solvers can be divided into two subproblems: (1) When and how are various reasoning modes invoked? and (2) How is information passed between various reasoning modes? In this paper, we explore some solutions to this problem. In particular, we describe a logic programming system that is based on three ideas: equivalence of declarative and operational semantics, declarative specification of control information, and smoothness of interaction with nonlogic-based programs. Meta-level predicates are used to specify control information declaratively, compensating for the absence of procedural constructs that usually facilitate formulation of efficient programs. Knowledge that has been derived in the course of the current inference process can at any time be passed to non-logic-based program modules. Traditional SLD inference engines maintain only the linear path to the current state in the SLD search tree: fonnulae that have been proved on this path are implicitly represented in a stack of recursive calls to the inference engine, and formulae that have been proved on previous, unsuccessful paths are lost altogether. In our system, previously proved formulae are maintained explicitly and therefore can be passed to other reasoning modules. As an application example, we show how this inference system acts as the knowledge representation and reasoning framework of PRET-a program that automates system identification. (C) 2003 Elsevier Inc. All rights reserved.
We prove some new results about the correctness of transformations of nondeterministic programs. The reported work formalises the intuitive idea that two recursive programs ought to be equivalent, also in a nondetermi...
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We prove some new results about the correctness of transformations of nondeterministic programs. The reported work formalises the intuitive idea that two recursive programs ought to be equivalent, also in a nondeterministic setting, if they can be symbolically unfolded, through deterministic reductions, to the same, possibly infinite, term. In order to do this we develop two related semantics, based on computations modeled by reduction sequences, and argue that they are operationally meaningful. We then specialise to the case of Combinatory Reduction Systems, which provides a suitable rewrite setting for higher order functional programs with nondeterministic constructs, e.g., stream or process primitives. In this setting we prove a theorem about equivalence of programs based on possibly infinite, deterministic unfoldings of programs converging to the same term. We then use the theorem to show a correctness criterion for unfold/fold-transformations of nondeterministic recursive programs. This criterion is similar to the well-known Tamaki-Sato correctness criterion for unfold/fold-transformations of logic programs.
Sharing, an abstract domain developed by D. Jacobs and A. Langen for the analysis of logic programs, derives useful aliasing information. It is well-known that a commonly used core of techniques, such as the integrati...
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Sharing, an abstract domain developed by D. Jacobs and A. Langen for the analysis of logic programs, derives useful aliasing information. It is well-known that a commonly used core of techniques, such as the integration of Sharing with freeness and linearity information, can significantly improve the precision of the analysis. However, a number of other proposals for refined domain combinations have been circulating for years. One feature that is common to these proposals is that they do not seem to have undergone a thorough experimental evaluation even with respect to the expected precision gains. In this paper we experimentally evaluate: helping Sharing with the definitely ground variables found using Pos, the domain of positive Boolean formulas;the incorporation of explicit structural information;a full implementation of the reduced product of Sharing and Pos;the issue of reordering the bindings in the computation of the abstract mgu;an original proposal for the addition of a new mode recording the set of variables that are deemed to be ground or free;a refilled way of using linearity to improve the analysis;the recovery of hidden information in the combination of Sharing with freeness information. Finally, we discuss the issue Of whether tracking compoundness allows the computation of more sharing information.
We propose a path-based framework for deriving and simplifying source-tracking information for first-order term unification in the empty theory. Such a framework is useful for diagnosing unification-based systems, inc...
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We propose a path-based framework for deriving and simplifying source-tracking information for first-order term unification in the empty theory. Such a framework is useful for diagnosing unification-based systems, including debugging of type errors in programs and the generation of success and failure proofs in logic programming. The objects of source-tracking are deductions in the logic of term unification. The semantics of deductions are paths over a unification graph whose labels form the suffix language of a semi-Dyck set. Based on this idea of unification paths, two algorithms for generating proofs are presented: the first uses context-free labeled shortest-path algorithms to generate optimal (shortest) proofs in time O(n(3)) for a fixed signature, where n is the number of vertices of the unification graph. The second algorithm integrates easily with standard unification algorithms, entailing an overhead of only a constant factor, but generates non-optimal proofs. These non-optimal proofs may be further simplified by group rewrite rules. (c) 2005 Elsevier Inc. All rights reserved.
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