DVB条件接收系统中独立加扰器的设计与实现

本文介绍DVB条件接收系统的基本结构，详细分析了条件接收系统的工作原理，并给出条件接收系统中独立加扰器SAS(Stand Alone Scrambler)的具体实现方案。     

国内3G网络共享问题之研究

随着国内3G时代的来临，3G网络共享问题越来越受到人们的关注。本文结合国内移动通信的现状，着重分析了3G网络共享的模式及经济效益，论述了3G网络共享的相应策略。     

Ethical issues concerning expert systems' applications in education

This article traces the connection between expert systems used as consultants in medicine and their design for instructional purposes in education. It is suggested that there are important differences between these applications. Recognizing these differences leads to the view that the development of intelligent computer-assisted instructions (ICAI) should be guided by empirical research into social/psychological consequences and by ethical inquiries into the acceptability of those consequences. Three proposals are put forward: (1) that the pedagogical role of intelligent CAI be clarified, (2) that forms of intelligent CAI be developed that aim primarily at refining rather than replacing human judgements, and (3) that ICAI research and development projects contain components which address ethical and social/psychological components and which are equitably-funded, integral parts of the overall development effort.This work was supported in part by funds from the Foundation of the University of North Carolina at Charlotte and from the State of North Carolina. An earlier version of this paper was read at the Human Dimension in Artificial Intelligence Symposium held at the University of Kentucky (April 1988).     

机电一体化设备控制系统的抗干扰措施

针对用单片机控制机电一体化设备必须解决的抗干扰问题,提出了一些对策,旨在提高控制系统的自适应能力,从而做到可靠运行。     

Controllability of One Spin and Two Interacting Spins

Mathematics of Control, Signals, and Systems - ?We consider the problem of steering control for the systems of one spin ½ particle and two interacting spin ½ particles in an...     

Generation and selection of likely interpretations during plan recognition in task-oriented consultation systems

This paper presents a mechanism which infers a user's plans from his/her utterances by directing the inference process towards the more likely interpretations of a speaker's statements among many possible interpretations. Our mechanism uses Bayesian theory of probability to assess the likelihood of an interpretation, and it complements this assessment by taking into consideration two aspects of an interpretation: its coherence and its information content. The coherence of an interpretation is determined by the relationships between the different statements in the discourse. The information content of an interpretation is a measure of how well defined the interpretation is in terms of the actions to be performed on the basis of this interpretation. This measure is used to guide the inference process towards interpretations with higher information content. The information content of an interpretation depends on the specificity and the certainty of the inferences in it, where the certainty of an inference depends on the knowledge on which the inference is based. Our mechanism has been developed for use in task-oriented consultation systems. The particular domain that we have chosen for exploration is that of travel booking.     

Stochastic nonlinear stabilization — II: Inverse optimality

After considering the stabilization of a specific class of stochastic nonlinear systems in a companion paper, in this second part, we address the classical question of when is a stabilizing (in probability) controller optimal and show that for every system with a stochastic control Lyapunov function it is possible to construct a controller which is optimal with respect to a meaningful cost functional. Then we return to the problem from Part I and design an optimal backstepping controller whose cost functional includes penalty on control effort and which has an infinite gain margin.     

数字式液压流量阀在工程机械中的应用

数字式流量阀是一种新研制开发的数字控制式流量阀，其调速控制响应快、精度高、稳定性好，应用于工程机械液压系统，可使工程机械的操纵控制系统面临新的变革。     

中原油田深井大井眼段钻井液工艺

濮深8井是中原油田在西部洼陷南部寻找接替储量的一口重点深探井,也是中原油田第一口井深达6000m的超深井。分析了濮深8井钻井液的配备及维护和处理技术,得出深井大井眼段钻井液工艺技术存在以下问题:井眼大,钻井液量及钻屑量多,处理时间长,处理剂用量多,处理频繁;返速低使钻井液清洗井眼的能力减弱;井下温度高使处理剂的作用明显降低,二氧化碳的侵入使钻井液性能变差。钻井液维护处理的较好方法是定时、定量补充处理剂胶液。固相控制是深井大井眼段钻井液工艺中的关键问题,必须配套并且有效地使用固控设备,以维护好钻井液性能。     

基于神经PID网络的串级调节系统研究

本文提出了一种神经PID网络控制器，并利用它构成串级调节系统。在给出网络结构和计算公式的基础上，进行了计算机仿真。仿真结果表明，神经PID网络控制器构成的串级调节系统具有良好的动态和静态性能及很强的抗扰能力。