线性时变系统的区间稳定性与鲁棒稳定性

本文应用向量比较定理研究线性时变系统的区间稳定性和具非线性时变摄动的线性时变系统的鲁棒稳定性，所得的新结果包含文献的一些主要结果作为特例，本文的研究方法说明向量比较方法是分析区间稳定性和鲁棒稳定性的一种自然而有力的工具。     

The rank one mixed μ problem and ‘kharitonov-type’ analysis

The general mixed μ problem has been shown to be NP hard, so that the exact solution of the general problem is computationally intractable, except for small problems. In this paper we consider not the general problem, but a particular special case of this problem, the rank one mixed μ problem. We show that for this case the mixed μ problem is equivalent to its upper bound (which is convex), and it can in fact be computed easily (and exactly). This special case is shown to be equivalent to the so-called ‘affine parameter variation’ problem (for a polynomial with perturbed coefficients) which has been examined in detail in the literature, and for which several celebrated ‘Kharitonov-type’ results have been proven.     

基于泛布尔代数的结构振动控制机理

本文介绍了泛布尔代数的数学模型、公理体系和化简方法 ;针对高层建筑的特点 ,舍弃寻求被控制对象的精确数学模型 ,提出了“基于泛布尔代数的结构振动控制” ,分析了其的逻辑机理 ,建立了基于泛布尔代数的MR阻尼器的半主动控制算法。应用本文提出的控制方针对 12层的高层结构受控地震反应的模拟仿真 ,结果表明其控制简单、灵活、方便 ,能满足这种结构的控制要求。     

Turbo码概率-代数联合解码算法

Turbo码采用修正的BAHL et al.算法实现解码.这是一种基于软值的概率迭代解码算法.本文在保持Turbo码迭代软解码算法优点的基础上,充分利用Turbo码编码器结构这一确知条件,结合代数解码原理,提出了一种Turbo码概率-代数联合解码算法.该算法结合了概率解码和代数解码的优点,又有效避免了误差传播的发生,使Turbo码的纠错性能在原经典算法的基础上得到进一步的提高.该算法不仅为降低Turbo码的比特误码率和误差地板值提供了一种新的研究途径,而且因其更好的纠错性能而具有十分明显的实用价值.仿真实验结果显示,在比特误码率(BER)为10^-3~10^-4时,与经典Turbo码解码算法相比,采用该算法能获得0.1dB左右的编码增益.     

An Interval Fuzzy Multiobjective Watershed Management Model for the Lake Qionghai Watershed, China

Integrated watershed management is required to ensure the reasonable use of resources and reconcile interactions among natural and human systems. In the present study, an interval fuzzy multiobjective programming (IFMOP) method was used to solve an integrated watershed management problem. Based on system analysis, an IFMOP model suitable for a lake watershed system {IFMOPLWS} was developed and applied to the Lake Qionghai watershed in China. Scenario analysis and an interactive approach were used in the solution process. In this manner, various system components were incorporated into one framework for holistic consideration and optimization. Integrality and uncertainty, as well as the multiobjective and dynamic characteristics of the watershed system, were well addressed. Using two scenarios, two planning schemes were generated. Agriculture, tourism, macroeconomics, cropland use, water supply, forest coverage, soil erosion, and water pollution were fully interpreted and compared to identify a preferable planning alternative for local agencies. This study showed that the IFMOPLWS is a powerful tool for integrated watershed management planning and can provide a solid base for sustainable watershed management.     

一种增强型冲突分解算法

冲突分解算法是一种能有效改善无线信道多址接入协议的方式。本文对传统的冲突分解算法——树形冲突分解算法和先到先服务冲突分解算法进行了深入研究和仿真，探讨了这两种算法的优点和不足之处，提出了一种增强型的冲突分解算法（Enhanced Splitting Algorithm，ESA）。该算法继承了树形冲突分解算法和先到先服务算法的优点，不仅考虑了碰撞分组产生的时间，还考虑了分组的产生间隔，从而有效地提高了冲突分解算法的性能。仿真结果显示ESA算法是一种可行的算法。     

利用地震属性钻前预测井壁稳定性

钻前准确预测井壁稳定性是防止钻进过程中井壁失稳的有效手段。声波时差和地层密度是井壁稳定分析的两个关键参数。根据地震记录与地层声波时差及密度之间存在的非线性关系，提出了利用地震属性钻前预测井壁稳定性的方法。从井旁地震记录中提取地震属性，通过RBF神经网络在已钻井段的地震属性与声波时差及密度之间建立起映射模型，以此为基础预测待钻地层的声波时差和密度。运用预测结果结合井壁稳定力学模型，确定岩石力学参数和地应力状态，计算井壁坍塌压力和破裂压力，确定安全钻井液密度窗口，实现钻前井壁稳定预测。该方法在塔里木油田的应用中取得了良好的预测效果。     

压水堆硼稀释事故的计算

一、概述核电厂压水堆的初始过剩反应性是通过控制捧、固体可燃毒物和溶解在主回路冷却剂中的硼酸等三种方式联合控制的。随着反应堆的燃耗和裂变毒物的积累,堆的过剩反应性不断减少,需要通过化容系统,控制硼酸的浓度来进行补偿。如果化容系统发生故障或操作员误操作,就会给回路注入无硼或低于规定浓度的补给水,给反应堆引入正反应性,造成硼稀释事故。按核安全法规的要求,应对换料、冷停堆、热停堆和启动等工况进行计算,并要求在这些     

区间系统在反馈控制情况下的性能鲁棒性

本文讨论含区间对象的反馈控制系统性能鲁棒性问题，给出了检验区间系统性能鲁棒性的充要条件．当补偿器满足某种假设条件时，给出了闭环系统性能鲁棒性的有限检验结果。在有限检验的前提下，给出了补偿器在系数空间中所应满足的制约条件。