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901.
用集成电路制成程序控制器,示教板性能稳定,寿命长,效果好,操作方便.其主要部分由电源、时钟、逻辑电路、输出驱动器四部分组成. 相似文献
902.
Manuel de León 《Reports on Mathematical Physics》2004,53(1):55-78
In this paper we study general symmetries for optimal control problems making use of the geometric formulation proposed in [7]. This framework allows us to reduce the number of equations associated with optimal control problems with symmetry and compare the solutions of the original system with the solutions of the reduced one. The reconstruction of the optimal controls starting from the reduced problem is also explored. 相似文献
903.
904.
Multi-Armed bandit problem revisited 总被引:1,自引:0,他引:1
In this paper, we revisit aspects of the multi-armed bandit problem in the earlier work (Ref. 1). An alternative proof of the optimality of the Gittins index rule is derived under the discounted reward criterion. The proof does not involve an explicit use of the interchange argument. The ideas of the proof are extended to derive the asymptotic optimality of the index rule under the average reward criterion. Problems involving superprocesses and arm-acquiring bandits are also reexamined. The properties of an optimal policy for an arm-acquiring bandit are discussed.This research was supported by NSF Grant IRI-91-20074. 相似文献
905.
Jos M. Asua 《Journal of polymer science. Part A, Polymer chemistry》2004,42(5):1025-1041
Emulsion polymers are “products by process” whose main properties are determined during polymerization. In this scenario of margins reduction, increasing competition, and public sensitivity to environmental issues, the challenge is to achieve an efficient production of high‐quality materials in a consistent, safe, and environmentally friendly way. This highlight reviews the investigations carried out at The University of the Basque Country to develop a knowledge‐based strategy to achieve these goals. First, the research in fundamental mechanisms is discussed. This includes studies in radical entry and exit, oil‐soluble initiators, propagation‐rate constants of acrylic monomers, processes involved in the formation of branched and crosslinked polymers, microstructure modification by postreaction operations, the formation of particle morphology, and reactive surfactants. The advanced mathematical models developed in the group are also reviewed. In the second part, the advances in process development (optimization, online monitoring and control, monomer removal, production of high‐solids, low‐viscosity latices, and process intensification) are presented. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 1025–1041, 2004 相似文献
906.
This paper studies an integrated decision making model for a supply chain system where a manufacturer faces a price-sensitive demand and multiple capacitated suppliers, two issues that are often considered separately in the literature. The goal is to maximize total profit by determining an optimal selling price and at the same time acquiring enough supplying capacity. The problem is proved to be NP-hard in the ordinary sense, a heuristic algorithm and an optimal dynamic programming algorithm are developed. Computational experiments are conducted to study the efficiency and effectiveness of the algorithms. Some managerial insights are observed. 相似文献
907.
A statistical process control approach to selecting a warm-up period for a discrete-event simulation
The selection of a warm-up period for a discrete-event simulation continues to be problematic. A variety of selection methods have been devised, and are briefly reviewed. It is apparent that no one method can be recommended above any other. A new approach, based upon the principles of statistical process control, is described (SPC method). Because simulation output data are often highly autocorrelated and potentially non-normal, the batch means method is employed in constructing the control chart. The SPC method is tested on seven data sets and encouraging results are obtained concerning its accuracy. The approach is also discussed with respect to its ease of implementation, simplicity, generality of use and requirements for parameter estimation. 相似文献
908.
本文根据有限区间上Riemann积分的Arzela控制收敛定理[1],给出无穷限积分的控制收敛定理,并做了相应的推广。 相似文献
909.
Stochastic control for systems with an unknown parameter is considered in this paper. The underlying problem is to minimize a functional subject to a system described by a singularly perturbed differential equation with an unknown parameter process driven by fast fluctuating random disturbances. This problem arises in the context of stochastic adaptive control, adaptive signal processing, and failure-prone manufacturing systems. Due to the nature of the wide-bandwidth noise processes, identifying the parameter process for eacht is very hard since the driving noise changes very rapidly. An alternative approach is used, and an auxiliary control problem is introduced to overcome the difficulties. By means of weak convergence methods and comparison control techniques, nearly optimal controls are obtained.This research was supported in part by the National Science Foundation under Grant DMS-9022139 and DMS-9224372. 相似文献
910.
报道了Na2+离子的三个低激发态1Σu、2Σg、2Σu在二个光脉冲作用下的解离动量谱,激光波长为680nm,各脉冲功率为1×1012W/cm2,脉宽50fs,从研究结果可见,其单光子、双光子、三光子激发的对应的解离峰及峰值随相对相位而变,并且这种影响随延时增大而减小. 相似文献