An iterative method for suboptimal control of linear time-delayed systems

This article presents a new approach for solving the Optimal Control Problem (OCP) of linear time-delay systems with a quadratic cost functional. The proposed method can also be used for designing optimal control time-delay systems with disturbance. In this study, the Variational Iteration Method (VIM) is employed to convert the original Time-Delay Optimal Control Problem (TDOCP) into a sequence of nonhomogeneous linear two-point boundary value problems (TPBVPs). The optimal control law obtained consists of an accurate linear feedback term and a nonlinear compensation term which is the limit of an adjoint vector sequence. The feedback term is determined by solving Riccati matrix differential equation. By using the finite-step iteration of a nonlinear compensation sequence, we can obtain a suboptimal control law. Finally, Illustrative examples are included to demonstrate the validity and applicability of the technique.     

The day of the week when you were born in 700 ms: Calendar computation in an autistic savant.

Some individuals are able to determine the weekday of a given date in a few seconds (finding for instance that June 12, 1900, was a Tuesday). This ability has fascinated scientists for many years because it is predominantly observed in people with limited intelligence and may appear very early in life. Exceptional visual memory, exceptional concentration abilities, or privileged access to lower levels of information not normally available through introspection have been advanced to explain such phenomena. In the present article, the authors show that a simple cognitive model can explain all aspects of the performance of Donny, a young autistic savant who is possibly the fastest and most accurate calendar prodigy ever described. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

最大塑性功原理在烧结体上限分析中的应用

最大塑性功原理又称第二塑性变分原理，在致密体塑性变形分析叶l是运用能量法进行变形力能计算的基础。本文从分析Drucker公设的亢要条件出发，证明了烧结体塑性变形最大塑性功原理的存在，片在该原理的荩础卜，推导出塑性变形的上限功率表达式，并以平面挤压条件下的上限法应用作为实例加以说明。     

纳米MOS器件的设计模型

几十年来，MOS器件一直遵循摩尔定律不断发展，对于缩小到纳米尺度的MOS器件，量子效应更加突出。研究纳米尺度MOS器件的物理问题，以及适用于纳米MOS器件的设计已成为当前微电子领域重要研究内容。本文简要介绍和评述了纳米MOS器件的设计模型．并对基于非平衡态格林函数以及薛定谔方程和泊松方程自洽解的器件模型应用进行了举例说明。     

钱塘江景观与文化关系初析

我国进入经济高速发展期后,人们在防洪抗旱得到安全保障、开发资源和治理江道等对河流的基本需求得到满足后,逐渐重视河流的景观和生态功能.从分析研究钱塘江下游河流景观特征、地理水文及人类活动对形成丰富多彩的景观的作用,以及一些以钱塘江为吟颂对象的诗词出发,初步探讨钱塘江景观多样性对人的性格、文学家风格的影响,最后从景观角度探讨河流治理的一些原则.     

A note on the value function for constrained control problems

We consider the Mayer optimal control problem with dynamics given by a nonconvex differential inclusion, whose trajectories are constrained to a given set and we obtain a relation between the costate function that appears in the maximum principle and the value function. This relation extends the known conditions existing in the literature for unconstrained problems to those for problems under state constraints.     

流域生态环境需水计算

介绍了我国流域生态需水研究现状,在对流域生态环境需水计算的前提条件进行阐述的基础上,根据生态需水的水文学原理以及生态系统学原理,从8个方面提出了流域生态环境需水的计算方法,以确定整个流域的生态环境需水量,从而合理量化生态需水总量,达到水资源优化配置的目的.     

微腔与腔量子电动力学研究进展

光学微腔中原子之自发辐射与自由空间中原子的自发辐射有着重要的不同。微腔能够控制腔内原子的自发辐射，使自发辐射得到抑制或增强，并有可能使自发辐射成为一个可逆过程。由此发展起来的腔量子电动力学能够阐述腔场与原子的相互作用。本文简要介绍了这一研究领域的背景和进展，同时介绍了微腔的重要应用一无阈值激光器。     

32位环境下微机原理与接口实践教学改革探讨

“微机原理与接口”类课程是目前在内容和方法上突出困扰高等学校电子信息与电气学科技术基础课程教学的课程之一。本文分析了目前32位环境下微机原理与接口实践教学面临的困难和任务，结合32位微机原理与接口理论教学的推广，提出了由16位微机到32位微机原理与接口实验的分层次过渡解决方案和基本实验内容，论述了正在探索研究中的新的实践教学体系。