铁铝酸盐复合膨胀水泥化学预应力机理及其应用研究

本文阐述铁铝酸盐自应力混凝土的主要物理力学特征.研究了限制膨胀应变与配筋率之间的定量函数关系.通过正交试验和方差分析,确定了复合外加剂对其性能的影响.针对其在自应力管中的应用,提出多层中空圆柱理论计算模型,按弹性理论计算出自应力管初始应力分布规律.对比以前的线性理论计算误差,给出相应的修正系数.本文对类似的自应力混凝土,具有普遍的指导意义.     

鄂北地区气测现场解释评价研究

鄂尔多斯盆地鄂北地区现场气测录井由于受多种因素影响,解释符合率相对较低。针对这一问题,在探讨影响气测录井显示因素、识别气测异常的基础上,分析了消除影响因素的途径和校正公式,建立了随钻全烃与全脱全烃的关系式,论述了地面和地层含气量计算方法。在初步评价气显示性质条件下,经统计分析得出了应用4参数——峰面积、校正全烃值、全烃计算值和地层含气量加权分值的解释评价标准,为鄂北地区气测录井解释评价和产能的初步预测探索了一种新模式,不但解决了鄂北地区气测解释符合率低的问题,而且对于深入开展气测录井参数与油气解释评价研究具有一定的参考意义。     

虚拟红外成像器件的模拟输出电路设计

虚拟红外成像器件是能输出红外图像数据源的器件,在调试图像采集系统的硬件和软件时能替代非制冷红外焦平面阵列。虚拟成像器件的输出具有很好的线性度和精度,可作为图像采集电路的标定器件。文设计了虚拟红外成像器件的模拟输出电路,根据UL03401性能参数,设计了信号调理电路,通过在FPGA上使用ROM中查表方式校正模拟端口输出误差,在实际应用中表现了良好的精确性。     

碗米坡水电站水机一级过速保护优化和改进

本文主要介绍了碗米坡电厂水机一级过速保护的组成部分和设计原则,分析了碗米坡水电厂水机一级过速保护在甩负荷试验中该保护误动作导致事故停机问题,并详细阐述相应的优化和处理方法。     

浅析计算机移动数据库的特点及应用

随着社会经济的快速发展,移动计算技术也随之发展,移动数据库逐步走向应用,在嵌入式操作系统中移动数据库更显示出其优越性。     

概率近似正确的强化学习算法解决连续状态空间控制问题

在线学习时长是强化学习算法的一个重要指标.传统在线强化学习算法如Q学习、状态–动作–奖励–状态–动作(state-action-reward-state-action,SARSA)等算法不能从理论分析角度给出定量的在线学习时长上界.本文引入概率近似正确(probably approximately correct,PAC)原理,为连续时间确定性系统设计基于数据的在线强化学习算法.这类算法有效记录在线数据,同时考虑强化学习算法对状态空间探索的需求,能够在有限在线学习时间内输出近似最优的控制.我们提出算法的两种实现方式,分别使用状态离散化和kd树(k-dimensional树)技术,存储数据和计算在线策略.最后我们将提出的两个算法应用在双连杆机械臂运动控制上,观察算法的效果并进行比较.     

Efficient PAC Learning for Episodic Tasks with Acyclic State Spaces

This paper considers the problem of computing an optimal policy for a Markov decision process, under lack of complete a priori knowledge of (1) the branching probability distributions determining the evolution of the process state upon the execution of the different actions, and (2) the probability distributions characterizing the immediate rewards returned by the environment as a result of the execution of these actions at different states of the process. In addition, it is assumed that the underlying process evolves in a repetitive, episodic manner, with each episode starting from a well-defined initial state and evolving over an acyclic state space. A novel efficient algorithm for this problem is proposed, and its convergence properties and computational complexity are rigorously characterized in the formal framework of computational learning theory. Furthermore, in the process of deriving the aforementioned results, the presented work generalizes Bechhofer’s “indifference-zone” approach for the ranking & selection problem, that arises in statistical inference theory, so that it applies to populations with bounded general distributions.

不同控制策略的小功率Boost-APFC性能研究

为了使用于小功率场合的功率因数校正电路的综合性能最优化,本文研究了采用电流断续模式或临界断续模式和电流连续模式的小功率Boost-APFC的各项性能。通过仿真分析和实验比较相结合的方法,定量给出了各电路在输入电流特性、效率、EMI滤波等性能上的具体差异,并且考虑了使用SiC二极管后对电路性能的影响。     

Move limits definition in structural optimization with sequential linear programming. Part II: Numerical examples

A variety of numerical methods have been proposed in literature in purpose to deal with the complexity and non-linearity of structural optimization problems. In practical design, sequential linear programming (SLP) is very popular because of its inherent simplicity and because linear solvers (e.g. Simplex) are easily available. However, SLP performance is sensitive to the definition of proper move limits for the design variables which task itself often involves considerable heuristics. This research presents a new SLP algorithm (LESLP) that implements an advanced technique for defining the move limits. The linearization error sequential linear programming (LESLP) algorithm is formulated so to overcome the traditional limitations of the SLP method. In a companion paper [Comput. Struct. 81 (2003) 197] the basics of the LESLP formulation along with a guide to programming are provided.The new algorithm is successfully tested in weight minimisation problems of truss structures with up to hundreds of design variables and thousands of constraints: sizing and configuration problems are considered. Optimization problems of non-truss structures are also presented. The numerical efficiency, advantages and drawbacks of LESLP are discussed and compared to those of other SLP algorithms recently published or implemented in commercial software packages.     

基于模糊逻辑控制技术的移动机器人路径跟踪中的偏差纠正

本文在分析移动机器人在路径跟踪中所产生的３种误差之间关系的基础上，提出了基于两个模糊子控制器的移动机器人路径跟踪纠偏的新方法．该方法简化了移动机器人的纠偏控制过程，改善了控制算法的实时性，提高了移动机器人的路径跟踪精度．