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71.
In this paper, we investigate a nonlinear Urysohn integral equation on unboundedinterval. We show that under some assumptions that the equation has monotonic solutions belonging to the space of functions being Lebesgue integrable on unbounded interval. The main tool used in our study is the technique associated with measures of weak noncompactness and measures of noncompactness in strong sense. 相似文献
72.
Matthias M. Müller 《Empirical Software Engineering》2004,9(4):335-351
From the first presentation of extreme programming on, pair programming has attracted a wide range of programmers to work together in front of one display. The proposed advantages of pair programming are a faster development cycle and code with higher quality. However, the nearly doubled personnel cost when compared to single developers seems to outweigh these advantages. Instead of showing the superiority of pair programming, we seek an alternative. Can a single developer be assisted by an already known technique with which he produces the quality of pairs with only a fraction of the cost? The answer with some restrictions is: yes, he can. Reviews are a reasonable candidate with respect to code quality and cost. 相似文献
73.
The authors’ work on lobster fishery in Chile is summarized in this paper. The paper presents the formulation and algorithmic resolution of a two-stage stochastic nonlinear programming model with recourse. The proposed model considers a long-term planning horizon and specifically allows an optimal total allowable catch quota to be obtained for the first planning period. This model takes into account biomass dynamics, the conditions guaranteeing sustained species management and uncertain parameters such as growth rate and species carrying capacity. These parameters are explicitly incorporated via a discrete random variable (scenarios). The proposed model is solved by Lagrangian decomposition using the algebraic modeling software AMPL, in combination with the solver MINOS to solve the nonlinear models resulting from the scenario decomposition. The article also presents the results obtained with this methodology and the conclusions drawn from the work. 相似文献
74.
We study a hybrid MIP/CP solution approach in which CP is used for detecting infeasibilities and generating cuts within a branch-and-cut algorithm for MIP. Our framework applies to MIP problems augmented by monotone constraints that can be handled by CP. We illustrate our approach on a generic multiple machine scheduling problem, and present a number of computational experiments. 相似文献
75.
Christopher Jefferson Angela Miguel Ian Miguel S. Armagan Tarim 《Computers & Operations Research》2006
Peg Solitaire is a well known puzzle, which can prove difficult despite its simple rules. Pegs are arranged on a board such that at least one ‘hole’ remains. By making draughts/checkers-like moves, pegs are gradually removed until no further moves are possible or some goal configuration is achieved. This paper considers the English variant, consisting of a board in a cross shape with 33 holes. Modelling Peg Solitaire via constraint or integer programming techniques presents a considerable challenge and is examined in detail. The merits of the resulting models are discussed and they are compared empirically. The sequential nature of the puzzle naturally conforms to a planning problem, hence we also present an experimental comparison with several leading AI planning systems. Other variants of the puzzle, such as ‘Fool's Solitaire’ and ‘Long-hop’ Solitaire are also considered. 相似文献
76.
77.
胡清淮 《武汉化工学院学报》2004,26(2):73-76
信息技术和生产率的发展以及全球经济一体化的发展趋势,使供应链成为全世界管理科学的热点.本文在阐述供应链基本数学模型的基础上,系统论述了用改进的广义上界(GUB)算法求解大型供应链问题的计算方法. 相似文献
78.
Piero A. Bonatti 《Artificial Intelligence》2004,156(1):75-111
This paper illustrates extensively the theoretical properties, the implementation issues, and the programming style underlying finitary programs. They are a class of normal logic programs whose consequences under the stable model semantics can be effectively computed, despite the fact that finitary programs admit function symbols (hence infinite domains) and recursion. From a theoretical point of view, finitary programs are interesting because they enjoy properties that are extremely unusual for a nonmonotonic formalism, such as compactness. From the application point of view, the theory of finitary programs shows how the existing technology for answer set programming can be extended from problem solving below the second level of the polynomial hierarchy to all semidecidable problems. Moreover, finitary programs allow a more natural encoding of recursive data structures and may increase the performance of credulous reasoners. 相似文献
79.
We bridge the gap between compositional evaluators and abstract machines for the lambda-calculus, using closure conversion, transformation into continuation-passing style, and defunctionalization of continuations. This article is a followup of our article at PPDP 2003, where we consider call by name and call by value. Here, however, we consider call by need.We derive a lazy abstract machine from an ordinary call-by-need evaluator that threads a heap of updatable cells. In this resulting abstract machine, the continuation fragment for updating a heap cell naturally appears as an ‘update marker’, an implementation technique that was invented for the Three Instruction Machine and subsequently used to construct lazy variants of Krivine's abstract machine. Tuning the evaluator leads to other implementation techniques such as unboxed values. The correctness of the resulting abstract machines is a corollary of the correctness of the original evaluators and of the program transformations used in the derivation. 相似文献
80.
Guo-hua Qin Wei-hong Zhang 《The International Journal of Advanced Manufacturing Technology》2007,32(1-2):78-91
After being located on a machine bed, a workpiece will be subject to gravity and cutting forces during the machining operation.
In order to keep the locating precision as well as the production safety, it is necessary to maintain the workpiece stability.
In this paper, a linear programming method is proposed for stability analysis of the workpiece. Based on the linear approximation
of the friction cone, a quantitative criterion is established to verify the workpiece stability in association with the rationality
of the clamping sequence, magnitude of clamping forces and clamping placement. This criterion allows designers to plan reasonably
the clamping sequence, magnitude of clamping forces as well as clamping placement. Compared with existing methods, the main
advantage of this approach lies in that the sophisticated computing of contact forces between fixture elements and the workpiece
is avoided. In this work, both friction and frictionless cases can be easily taken into account in stability analysis. Mathematical
formulations of the method are given and some numerical tests are finally demonstrated to validate the proposed method. 相似文献