Archimedean copula左尾相依性的判定

对于Archimedean copula,左尾递减序列(LTDS)、多变量左尾递减(MLTD)和左尾递减(LTD)这3个左尾正相依概念是等价的,并给出了这些正相依概念与Archimedean copula的生成元之间的等价刻划.     

联合重要度在部件相依时的兼容性算法

在含有相依部件的系统中提出一个联合重要度的兼容性算法，即在基本部件不独立（相依）条件下，将故障树的系统结构特点和部件自身的可靠性因素兼容考虑进行联合重要度计算，并将此算法同其它算法的计算结果进行比较，从而验证说明这一算法的有效性．     

具无穷时滞中立型泛函微分方程的解的存在性、唯一性及连续相依性

本文研究了无穷时滞中立型泛函微分方程的解的局部理论.为了便于应用,得到了具无穷时滞中立型泛函微分方程的解的存在性、唯一性及关于初值的连续相依性.     

机械零部件失效相依方向可靠性模型

为判定机械结构系统可靠性工程中相关性失效的相依方向,在线性回归背景下,根据线性相关系数的特性,建立了可靠性变量判定模型.应用Copula回归函数,将该模型扩展到对一般非对称型相关结构可靠性的相关性失效方向判定,并应用于判定机车设备转轴的磨损失效和变形失效相关性失效方向,得到其磨损量偏度系数、变形量偏度系数分别为2.362×10-6和9.665×10-33.研究结果表明,磨损失效占有主导地位,与实际转轴的主要失效形式一致,验证了该模型的有效性.      

二元二次孙数逼近的解析性质

对于原点附近展成幂级数的二元函数,研究了对角二元二次函数逼近的存在性以及原点附近的局部性质,证明了对角二元二次函数逼近总能得到在原点的某邻域内解要并且满足一定逼近阶的函数。     

二元二次孙数逼近的解析性质

对于原点附近展成幂级数的二元函数,研究了对角二元二次函数逼近的存在性以及原点附近的局部性质,证明了对角二元二次函数逼近总能得到在原点的某邻域内解要并且满足一定逼近阶的函数。     

二元二次函数逼近的解析性质

对于原点附近展成幂级数的二元函数,研究了对角二元二次函数逼近的存在性以及原点附近的局部性质,证明了对角二元二次函数逼近总能得到在原点的某邻域内解要并且满足一定逼近阶的函数.     

新二元模型结构在电力电子电路仿真中的应用

提出了用数字计算机对电力电子电路进行仿真的一种新的方法,半导体开关被描述成一种二元电感模型,在它导通期间,共电感值很小;而在它截止期间,其电感值为穷大,本文中给出了如何确定此小电感值的方法,采用改进节点法来建立方程,再利用ＢａｃｋｗａｒｄＥｕｌｅｒ积分方法来求解以确保值其收敛性,该方法能有效监控开关的状态,拓扑结构的变化通过量少的计算予以解决。     

二元回归法在车削力试验软件中的应用

介绍了采用VisualC 6.0编程工具，运用二元线性回归法编制在线处理车削力试验数据，建立车削三分力各自的经验公式和打印完整的试验报告的软件设计方法及其应用实例。使用二元线性回归法与传统的图解法和一元线性回归法相比，充分发挥了计算机技术的优势，试验中切削参数的选择方便、灵活，且计算一步到位，得出的结论准确、可信。     

路基压实与沥青路面使用寿命的关系

道路路基的强度直接影响路面的使用寿命,通过二者之间关系的探讨,对于不同压实度条件下的土基回弹模量进行换算。根据现行沥青路面设计规范拟定高速公路、二级公路、三级公路路面结构和交通参数,计算不同路基压实度条件下的遗路承载能力,计算得知道路工程使用寿命与路基强度有着密切关系,计算结果认为每低于规定路基压实度1％路面的使用寿命缩短0．3～0．5年。     

一类非自治二阶系统的周期解

研究了一类非自治二阶系统周期解的存在性。给出了一些新的存在条件,在这些条件下,使用极小作用原理,得到了4个新的存在性定理。     

考虑驾驶员预测特性的带有上匝道的宏观交通流模型

高速公路入口匝道车流对高速公路主路车流存在较大影响，在未来车联网环境下，驾驶员能够获取更为丰富的交通信息，并对下一时段的交通状态做出预判.本文提出考虑有驾驶员预测特性的带有匝道的新格点流体动力学模型.基于线性稳定性分析方法，得到关于新格点模型的中性稳定性条件；在非线性稳定性分析中，采用还原扰动法推导模型在临界点附近的mKdV(modified Korteweg de Vries)方程，求解方程所得的扭结-反扭结孤立波，可以用于描述交通密度波在中性稳定曲线附近的传播机制.最后，基于仿真算例验证匝道交通流率和驾驶员预测时间对交通流稳定性的重要影响.     

Classification of Stably Dissipative 3D Lotka-Volterra Systems and Their Necessary and Sufficient Condition for Being Stably Dissipative

By introducing the concepts of stably dissipative matrix and graph, some criteria conditions for stably dissipative matrix were given. On this basis, the method of graph theory was used to classify all stably dissipative 3D Lotka-Volterra systems and five classes of maximal stably dissipative graphs were obtained for these systems. Finally, the necessary and sufficient condition of being stably dissipative for every class was studied, under which the matrix associated with the graph is stably dissipative.     

New unified failure model on evenly distributed reinforced concrete members with box section

It is urgently needed to describe the structural collapse process under extreme conditions to survive people.For reinforced concrete structures it is still a difficulty to describe the failure of reinforced concrete members under complex internal force combination,such as under axial forces,bending moment,shear forces, and torsion working together.In this paper,based on the traditional Nielsen model,a new unified failure model on reinforcement evenly distributed concrete members with box section under combined forces is introduced.The advantages of the proposed new model are to consider the dowel actions of reinforcements and reasonably to consider of the shear carrying capacity of concrete,especially when compression stress of concrete is in a high value.Finally,the theoretical results of the new model are compared with a series of experimental results of box section members.The comparison has verified that the new model is more accurate and feasible for the design and calculation of box section members.     

矩阵损失下带约束生长曲线模型中齐次线性估计的可容许性特征

证明了约束条件下生长曲线模型中线性估计的可容许性与约束条件下一元线性模型中,线性估计的可容许性在齐次线性估计类中具有等价性,得到了带约束生长曲线模型中线性函数KBL的估计DYF在齐次线性估计类中是可容许估计的充要条件．     

一类大规模运输网络多阶段随机规划配流模型

利用随机规划理论，分析大规模运输网络的基本特性及优化，是近几年交通运输领域发展起来的一种新的研究方向，已广泛地应用于交通运输管理的各个部门。本文在分析了一类大规模运输网络在市场经济模式下的基本特性的基础上，提出了一类适用范围更广、更复杂的多阶段和广义多阶段随机规划配流模型。     

A NOVEL CONTROL STRATEGY FOR SINUSIODAL WAVE INVERTER WITH PI REGULATORS AND CAPACITOR CURRENT FEEDBACK

Inmodernuninterruptablepowersupplies ,in verterswith pulsewidthmodulation (PWM )con trolareusedtogeneratethesinusoidaloutputvolt age .Therequirementstoinvertersincludeahighstability ,highreliability ,fastdynamicresponseoveralltypesofloads,aswellasminimumtotalharmonicdistortion .Inthepast,openloopcontrolwithfeed for wardwereusedininverterstoproducethesinusoi dalwaveoutput ,whilearelativelyslowoutputvoltagermsfeedbackloopwereusedtoregulatethermsoftheoutputvoltage .Althoughthistypeofcontrolcould…     

Approach for Reliability Evaluation of Cross-Linked Polyethylene Under Combined Thermal and Vibration Stresses

Based on Wiener process model, a new approach for reliability evaluation of cross-linked polyethylene(XLPE) is proposed to improve the lifetime evaluation reliability of XLPE under multi-stressing conditions and study the failure probability distribution. In this paper, two accelerated aging tests are carried out under combined thermal and vibration conditions. The volume resistance degradation data of XLPE samples are tested with a24 h interval under the accelerated stressing conditions at(130℃, 12 m/s~2) and(150℃, 8.5 m/s~2), respectively.Nonlinear degradation data obtained from the experiment are transformed to linear intermediate-variable values using time scaling function, and then linearized degradation data are calculated and evaluated on the basis of linear Wiener process model. Considering traditional Arrhenius equation and inverse power criterion, parameters of the linear Wiener model are estimated according to the maximum likelihood function. The relationship curves on probability density and reliability are given, and the lifetime distribution of XLPE under different stressing conditions is also obtained for evaluating the reliability of XLPE insulation. Finally, the life expectancy of XLPE is 17.9 a under an allowance temperature of 90℃ and an actual vibration acceleration of 0.5 m/s~2. The approach and results in this paper may be used for reliability assessment of high-voltage multiple samples or apparatuses.     

Robust stability of neutral systems: A discretized Lyapunov functional method

This paper focuses on the robust stability for time-delay systems of neutral type. A new complete Lyapunov-Krasovskii function (LKF) is developed. Based on this function and discretization, stability conditions in terms of linear matrix inequalities are obtained. A class of time-varying uncertainty of system matrices can be studied by the method. Foundation item: the National High Technology Research and Development Program (863) of China (No. 2006AA05Z148)