Multigrid optimization methods for linear and bilinear elliptic optimal control problems

Summary Multigrid optimization schemes that solve elliptic linear and bilinear optimal control problems are discussed. For the solution of these problems, the multigrid for optimization (MGOPT) method and the collective smoothing multigrid (CSMG) method are developed and compared. It is shown that though these two methods are formally similar, they provide different approaches to computational optimization with partial differential equations.      

Fuzzy radicals and prime fuzzy ideals of ordered semigroups

Let S be an ordered semigroup. A fuzzy subset of S is, by definition, an arbitrary mapping f: S → [0, 1], where [0, 1] is the usual interval of real numbers. Motivated by studying prime fuzzy ideals in rings, semigroups and ordered semigroups, and as a continuation of Kehayopulu and Tsingelis’s works in ordered semigroups in terms of fuzzy subsets, in this paper we introduce the notion of ordered fuzzy points of an ordered semigroup S, and give a characterization of prime fuzzy ideals of an ordered semigroup S. We also introduce the concepts of weakly prime fuzzy ideals, completely prime fuzzy ideals, completely semiprime fuzzy ideals and weakly completely prime fuzzy ideals of an ordered semigroup S, and establish the relationship between the five classes of ideals. Furthermore, we characterize weakly prime fuzzy ideals, completely semiprime fuzzy ideals and weakly completely prime fuzzy ideals of S by their level ideals. Finally, we introduce and investigate the fuzzy radicals of ordered semigroups by means of ordered fuzzy points, and prove that the fuzzy radical of every completely semiprime fuzzy ideal of an ordered semigroup S can be expressed as the intersection of all weakly completely prime fuzzy ideals containing it. As an application of the results of this paper, the corresponding results of semigroups (without order) are also obtained.     

Fractional Adams–Moulton methods

In the simulation of dynamical systems exhibiting an ultraslow decay, differential equations of fractional order have been successfully proposed. In this paper we consider the problem of numerically solving fractional differential equations by means of a generalization of k  -step Adams–Moulton multistep methods. Our investigation is focused on stability properties and we determine intervals for the fractional order for which methods are at least A(π/2)$A(\pi /2)$-stable. Moreover we prove the A-stable character of k  -step methods for k=0$k=0$ and k=1$k=1$.     

A note on attraction and stability of neutral stochastic delay differential equations with Markovian switching

This paper is concerned with neutral stochastic delay differential equations with Markovian switching (NSDDEs-MS). A kind of ψ ??function is introduced and some criteria on the attractor for the product of the ψ ??function are obtained. By the new criteria, the almost sure stability with the general decay rate of NSDDEs-MS could be examined, including the exponential stability and the polynomial stability. Finally, an example is provided to illustrate the applications of our results clearly.     

微机控制广电专用稳压器应用解析

对微机控制广电专用稳压器在我台实际应用过程中出现的设备安装、控制软件调试、典型故障及使用维护经验进行了解析,并且提出了一些维护技巧和方法供工程技术人员参考。     

青藏铁路冻土监测无线传感器网络节点设计

着眼于对青藏铁路沿线多年冻土区典型段地温进行自动监测,并将所检测的数据传入监控中心,与其它有关信息综合分析、处理,设计了基于无线传感器网络WSN(wireless sensor networks)的青藏铁路冻土温度自动监测系统。该节点以CC2430为核心,通过温度传感器DS18B20对青藏铁路冻土温度进行监测。由其构成的WSN可为千里青藏铁路冻土区的安全运营和养护维修提供及时、有效、准确的监测数据,并对铁路长期运营、维修和养护提供科学依据。     

基于PROTEUS的DS18820数字温度计的仿真实现

Proteus是英国Labcenter公司开发的一种交互式、可视化的电路分析与实物仿真软件。本文介绍了应用Proteus的ISIS软件进行DS18820数字温度计的实现方法。该方法仿真效果真实、准确,可以提高开发效率、降低开发成本,具有推广价值。