General symmetries in optimal control

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.     

随机性参数自适应的混沌同步

对两个不同参数的混沌系统进行随机性参数自适应控制，选取合适的控制律和反馈系数，导致其同步.以Henon映射为例进行数值模拟，结果表明，由于控制周期和反馈系数的随机变化，具有一定的实用意义. 关键词： Henon映射 混沌同步 随机性自适应控制     

Multi-Armed bandit problem revisited

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.     

Emulsion polymerization: From fundamental mechanisms to process developments

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     

Minmax scheduling with job-classes and earliness–tardiness costs

We address scheduling problems with job-dependent due-dates and general (possibly nonlinear and asymmetric) earliness and tardiness costs. The number of distinct due-dates is substantially smaller than the number of jobs, thus jobs are partitioned to classes, where all jobs of a given class share a common due-date. We consider the settings of a single machine and parallel identical machines. Our objective is of a minmax type, i.e., we seek a schedule that minimizes the maximum earliness/tardiness cost among all jobs.     

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.     

无穷限积分的控制收敛理论

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。     

Near optimality of stochastic control in systems with unknown parameter processes

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.     

二个强飞秒延时激光脉冲的相对相位对Na2+光解离的影响

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.     

线性动态系统的神经网络辨识与控制

近年来，不同结构的神经网络已成功地用于一大类动态系统的辩识与控制。本文应用函数型链接网提出一实际可行的辨识器与状态反馈控制器；研究的问题主要是线性动态系统在状态可测情形下在平衡点镇定问题。仿真结果显示了本文提出的方法的有效性。