A new two‐phase structure‐preserving doubling algorithm for critically singular M‐matrix algebraic Riccati equations

Among numerous iterative methods for solving the minimal nonnegative solution of an M‐matrix algebraic Riccati equation, the structure‐preserving doubling algorithm (SDA) stands out owing to its overall efficiency as well as accuracy. SDA is globally convergent and its convergence is quadratic, except for the critical case for which it converges linearly with the linear rate 1/2. In this paper, we first undertake a delineatory convergence analysis that reveals that the approximations by SDA can be decomposed into two components: the stable component that converges quadratically and the rank‐one component that converges linearly with the linear rate 1/2. Our analysis also shows that as soon as the stable component is fully converged, the rank‐one component can be accurately recovered. We then propose an efficient hybrid method, called the two‐phase SDA, for which the SDA iteration is stopped as soon as it is determined that the stable component is fully converged. Therefore, this two‐phase SDA saves those SDA iterative steps that previously have to have for the rank‐one component to be computed accurately, and thus essentially, it can be regarded as a quadratically convergent method. Numerical results confirm our analysis and demonstrate the efficiency of the new two‐phase SDA. Copyright © 2015 John Wiley & Sons, Ltd.     

Web应用测试模型研究

本文基于模型驱动测试的思想，提出一种Web应用测试模型WANM（Web Application Navigation Model），用于支持测试用例的设计与自动执行．基于WANM设计的测试用例的描述参照U2TP（UML2．0 Testing Profile）标准，使得测试建模、测试用例生成以及测试执行既紧密联系又相互独立，有助于提高测试的充分性与效室．     

“实验化学”翻转课堂教学案例设计

针对实验化学课程的特点,探讨了实验化学“课前知识传递,课堂知识内化,课后反思提高”的翻转课堂教学设计。以“硫酸亚铁铵的制备”为实验案例,通过翻转课堂在学习目标、活动主体与教学流程上的教学设计,详细阐述了以学生为中心的教学实施,并全面评价了教学实践。     

Global Approximation of Solutions of Time-Dependent Variational Inequalities

We consider a class of parametric variational inequalities where both the operator and the convex set depend on time. This kind of variational inequalities are useful to model many time dependent equilibrium problems. We study the Lipschitz continuity of the solutions with respect to the time parameter and construct approximations for them which minimize the average worst case error. Some improved estimates of the Lipschitz constant for this class of problems are given. In order to illustrate our procedure, we study a classical network equilibrium problem.     

麻省理工学院物理教育状况研究

通过对麻省理工学院物理教育理念、专业设置、课程体系、教材选用情况和教学方式的分析与研究,进一步了解MIT物理教育的特点以及培养拔尖创新人才的模式,可对我国大学的物理教育改革提供一些科学的参考和启示.     

塑壳断路器延时特性自动检测系统

针对塑壳断路器出厂前延时特性可靠性检测,开发一套塑壳断路器延时特性自动检测系统。该系统以PLC为核心,通过触摸屏设置参数,恒流源输自动调节所需试验电流,并根据测试结果进行分类,提高了生产效率和生产的规范性。     

教育实证研究中样本选择的原则及品质要求

我国教育研究领域大力倡导实证研究,却面临操作指南缺乏和品质标准不够明晰的问题,导致高质量的实证研究案例不多。研究样本的数量及其代表性或立意是保证实证研究品质的重要因素,讨论了定量研究和质性研究中选择研究样本的原则,明确了实证研究论文写作中研究样本部分的品质指标及内容要求,利用构建的品质指标及内容要求分析了4个教育实证研究论文案例。研究发现,提升我国教育实证研究质量的任务还是比较艰巨的。     

Stability in critical cases of a holonomic mechanical system with two degrees of freedom subject to impacts

Stability conditions for a holonomic impulsive mechanical system with two degrees of freedom in the critical case of one pair of complex-conjugate multipliers are established. An analog of the first Lyapunov exponent is calculated __________ Translated from Prikladnaya Mekhanika, Vol. 44, No. 6, pp. 105–117, June 2008.     

基于IP核开发模式的高校集成电路设计发展策略研究

针对当前集成电路领域企业缺少原始技术积累、高校成果转化困难的问题，提出一种以IP核合作方式促进高校集成电路设计加快发展、实现高校企业双赢的创新机制。高校作为我国IC产业链中不可缺少的一部分，以西安交通大学SoC设计中心近十年来的发展历程为案例进行分析，提出基于IP核开发的高校集成电路设计发展的具体策略。     

Theory of optimal consumption and portfolio selection under a Capital-at-Risk (CaR) and a Value-at-Risk (VaR) constraint

The solution to the optimal portfolio selection and consumptionrule subject to Capital-at-Risk and Value-at-Risk constraintsis derived via the use of stochastic dynamic programming.