Estimation of the extended Weibull parameters and acceleration factors in the step-stress accelerated life tests under an adaptive progressively hybrid censoring data

ABSTRACT

Based on the tampered failure rate model under the adaptive Type-II progressively hybrid censoring data, we discuss the maximum likelihood estimators of the unknown parameters and acceleration factors in the general step-stress accelerated life tests in this paper. We also construct the exact and unique confidence interval for the extended Weibull shape parameter. In the numerical analysis, we describe the simulation procedures to obtain the adaptive Type-II progressively hybrid censoring data in the step-stress accelerated life tests and present an experimental data to illustrate the performance of the estimators.     

以C8051F020为核心的交流伺服控制系统

目前数字伺服驱动广泛采用单片机或数字信号处理器（DSP）来实现数字控制算法,控制算法复杂,而且基本上是单自由度控制器。交流伺服驱动器的控制包括信号的测量、滤波、核心算法的实时完成,驱动信号的产生和系统的监控、保护等功能。据此设计出了基于C8051F020单片机的多自由度伺服驱动控制器,使硬件和控制算法上都大为简化。     

基于混合聚类的层次教学模式分组实践

在高校计算机基础课中,由于学生的计算机学习能力及兴趣取向不同,为了提高教学质量和效果,有必要有针对性地实施分层次教学。本文通过采用K—prototypes混合聚类分析的方法,把学生的兴趣与能力分别用分类属性和数值属性加以标识,对学生进行教学分组,为有效实施分层次教学模式提供保障。     

基于单片机的步进电机控制系统的设计

采用AT89S51单片机,设计了步进电机控制系统,该系统主要由按键电路、单片机最小系统、AT89S51单片机、步进电机状态显示电路、驱动电路以及步进电机等几部分组成,不仅可以实现电机的正反转,还可以实现17级调速,以及LED状态显示功能.系统设计可靠且易于实现,程序设计简单易懂.     

考虑最坏中断损失下的P-中位设施选址问题的模型与算法研究

蓄意突袭以及恐怖袭击会造成设施服务的突然中断成为网络系统的主要危害之一,因此网络设施选址决策应该同时考虑正常和紧急状态下系统的运作成本.本文研究考虑最坏中断损失下的网络设施选址问题,建立了该问题的双层规划模型,上层规划涉及设施选址决策,下层规划研究确定设施位置后,设施中断产生最大损失的问题.本文运用基于拉格朗日松弛的混合遗传算法来求解该双层规划问题.将European150数据集作为研究对象,对比研究了本文研究问题与传统的P-中位选址问题的结果,分析不同选址策略下网络系统的效率被中断影响的程度是不同的.最后通过改变一些关键参数,比如常规运作权重、设施数量、中断设施数量,对相关结果进行了分析.     

允许直达的混合轴辐式快递网络规划模型与算法研究

在快递企业的日常运营中,当两个城市之间的快递业务量达到一定规模之后会允许该城市对之间开展直达递送。但是这一规则通常仅在快递网络规划完成之后由相关子公司提请实施。为弥补这一实际规则的局部最优性缺陷,本论文将直达问题纳入网络规划决策,基于全局优化的视角构建了允许直达的混合轴幅式快递网络规划决策模型,设计了相应的求解流程,并对其中的指派关系决策构建了遗传算法。基于国内标杆企业的数值案例计算证明了该决策模型与求解方法的有效性,研究结果还说明,相对于纯轴辐式结构,允许直达的混合轴幅式网络结构有助于降低网络总成本,同时在直达线路上能够有效的降低迂回、提高服务时效性和服务水平。     

Internationally Adopted Children After Arrival: Temperament,Behavior Problems,and Age at Adoption as Predictors of Early Motor and Communication Competence

The temperament dimensions activity, emotionality, and shyness, together with behavior problems, gender, country of birth, and age at adoption, were explored in relation to early motor and communication competence among internationally adopted children in Norway (N = 106, gender: 55 girls and 51 boys, age at adoption: M = 9.99 months, SD = 4.29 months). Based on reports from adoptive mothers, regression analysis including all the variables showed that 56% of the variance in motor competence and 64% in communication competence were explained. Age at adoption explained most of the variance in both areas, while increased level of activity showed a significant correlation with improved motor competence.     

Images of Jewish identities in Lithuanian literature of the twentieth century: Grigorii Kanovich and Markas Zingeris

This paper deals with the identity concept of two Lithuanian Jewish writers, Grigorii Kanovich and Markas Zingeris. Kanovich, as a member of the Holocaust generation, writing in Russian, depicts his protagonists as spiritual and hardworking people with strong self‐confidence, resting on religion and custom. By means of the narrative technique of memory, Kanovich creates a literary resurrection of the Lithuanian Jews as a people which was almost completely exterminated during the Holocaust. Omnipresent pictures of cemetery and grave transform the Lithuanian space into a metonymy of death and, grotesquely, to the only place of home, being the “shelter” for the killed bodies of the Lithuanian Jewry. Markas Zingeris, growing up in post‐war Soviet Lithuania, represents the concept of open identities, changeable in time and place. Calling himself a Lithuanian writer who has been raised within a Lithuanian, Jewish, and, not least, Soviet milieu, Zingeris depicts his protagonists in in‐between situations. Writing in Lithuanian, speaking several languages fluently and working as translator, Zingeris embodies the cosmopolite. At the same time, though, he is a writer of collective memory. He comments on the apparent loss of the great utopia of an autonomous identity with ironic melancholy, pointing instead to the rich variety of hybrid identities.     

Framing and counter-framing a Peace March in Russia: the use of Twitter during a hybrid war

ABSTRACT

Framing is vital to the capacity of social movements to enlist popular support and sustain contentious collective action. Using the case of a Peace March held in Moscow on 21 September 2014, the article examines how antiwar activists and their opponents framed a protest against Russia’s intervention in Ukraine. The study argues that different interpretations of patriotism underpinned divergent evaluations of the conflict and the construction of opposing identities. An analysis of Twitter posts on the eve of the march shows that peace activists positioned themselves as citizens with high moral standards and a healthy dose of patriotism, criticized the Russian government for military intervention in Ukraine, and called for a peaceful conflict resolution. In turn, opponents of the march considered themselves as real patriots and their adversaries as national traitors, denied Russia’s military presence in Ukraine, and fomented an attack on critics of Russian foreign policy. The study contributes to social movement literature by analyzing the framing of antiwar activism on a social media platform in the midst of a hybrid war, marked by a great deal of ambiguity and deception about causes, dynamics, and consequences of military operations by state and non-state actors.     

基于混合差分进化算法的联合补货-配送优化模型

本文综合考虑联合补货与配送决策,研究了随机需求、允许缺货环境下多企业多产品联合补货与配送集成优化模型,设计了混合差分进化算法(Hybrid Differential Evolution, HDE)对该模型进行求解,同时通过算例与遗传算法、标准的DE算法进行了比较,证实HDE算法高效且稳定;另外,设计了一个先补货再配送的两阶段优化模型,对比优化结果发现采用供应链协同时补货成本较高,配送成本较低,且总成本较低。最后,对相关参数进行了敏感性分析,发现需求率和库存维持成本的变动对总成本的影响远远大过次要订货成本对总成本的影响。