机械产品精密配合中的选配方法研究

在对配合精度要求较高的产品(或部件)进行装配时,为了得到它的最优装配组合,运用网络流规划建立了一种特定装配关系的选配模型,通过合理定义模型网络的中间点、弧的容量和方向以及模型的一般约束条件,将最优装配组合的问题转化成网络最大流问题。结合关联图模型和产品层次装配模型的特点,建立了一种便于选配模型求解的装配模型,采用了分层自底向上的选配方法,利用选配模型进行局部选配最终获得最优解。并通过实例对上述方法进行了验证。     

装配生产线的平衡问题研究

讨论了装配过程中的生产平衡问题，介绍了最大候选原则和分级位置权(RPW)法2种装配线平衡的人工方法，结合实例介绍了2种方法在装配线平衡问题上的应用，并对比分析了2种不同方法分配装配作业的装配线效率。     

冷室压铸机最大空压射速度的意义

冷室压铸机最大空压射速度表示压铸机所能提供的压射能量,也表示在较短充型时间内能向型腔内充填大容量的金属熔体,以及与模具特性一起表示工艺灵活性.     

非高斯系统的建模方法研究*

近年来，高阶统计信息理论广泛应用于非高斯系统的建模问题中，由于高阶统计信息方法特殊的信息结构，难以充分利用具体问题中的统计分布信息，从而对该方法的应用效果产生了影响。针对这一问题，本文提出一种综合应用刘阶统计信息理论与非高斯系统的似然函数指标的建模的方法，为在非高斯系统建模系统建模问题中充分利用问题所提供的统计信息提供了新的途径，仿真研究和应用取得了令人满意的效果。     

自适应功率估计算法的计算机仿真

本文提出并建立了一种称之为功率估计算法的ＭＴＩ滤波算法,与现有的自适应算法相比,它具有结构简单,易于工程实现之优点。基于这个算法已构成了一个最优低阶自适应ＭＴＩ系统的模型,计算机仿真结果表明,这个系统的性能十分逼近于理想系统,从而证明了新算法的正确性和可行性。     

Maximum likelihood estimation for generalized semi-markov processes

Parametric statistical inference for generalized semi-Markov processes is addressed. This class of processes encompasses a large number of real-world discrete-event stochastic systems. Because of its properties (e.g., consistency, asymptotic normality, etc.), maximum likelihood estimation is considered here. Under reasonable conditions on the process, we show that a maximum likelihood estimator exists, and that it converges to the true parameter at ratet ^–1/2, wheret is the length of the observation period. A related estimator, which is typically easier to compute, is also introduced. We show that the use of this estimator results in no loss of statistical efficiency. It is also shown that the estimation problem does decouple into separate subproblems when the process' transition probabilities and event distributions depend on different parameters.     

基于多元正态分布的飞秒激光烧蚀光斑质心提取

飞秒激光在加工单晶硅过程中伴随着等离子体衍生发光现象,并以激光光斑形式表现出来,激光烧蚀效果受激光脉冲能量、光学设置、材料特性、环境参数等因素的影响,参数的选择是实现理想加工的关键,由此引入光斑质心的提取,研究光斑的变化规律以提高加工精度的目的。常用的质心提取算法有灰度质心法、高斯曲面拟合法等,但由于受到噪声的影响,光斑的灰度峰值可能发生偏差,提取的质心同真实质心相比误差较大,由此引入多元正态分布,在多个方向拟合高斯曲面,通过极大似然法估计质心,在精度方面得到了很大的改善。     

An elaboration likelihood model of consumer respond action to facebook second-hand marketplace: Impulsiveness as a moderator

The Elaboration Likelihood Model is adopted in this study to examine the interaction of central route factors (information completeness and information accuracy) and peripheral route factors (post esthetics and post popularity) on consumer behavior in the Facebook Second-hand Marketplace. Impulsiveness served as a moderator affecting the relationship between consumer attitudes and behavior. Eight scenarios were designed to test the effects of post characteristics on consumer responses and purchase behavior. Hedonic and utilitarian products were used in the scenarios to compare the differences among different product types. A total of 908 valid questionnaires were collected. The results of the data analysis indicated that consumers who process messages through the central route tend to respond to the post before initiating purchase intention. On the other hand, consumers who process messages through the peripheral route tend to initiate purchase intention directly if they feel favorable toward a post. Regarding the post characteristics, post popularity was found to be the most crucial factor related to enhancing perceived persuasiveness. According to the results and findings, it is suggested that sellers on the Facebook Second-hand Marketplace should provide messages about their product as accurately as completely as possible to strengthen positive impressions of their posts. Otherwise, they need to provide an interesting introduction or esthetic pictures to attract consumer attention.     

基于并行约束规划的最大团识别研究

为提高大数据平台下大规模图例的最大团问题求解效率,提出一种基于并行约束规划的最大团识别算法.通过BMT图划分策略将一个复杂图例分割为若干个可独立计算的子图,并将其分配给Spark集群中的计算节点,每个计算节点采用约束规划方法对分割产生的子问题分别进行建模和求解,实现最大团问题的并行化处理.引入时间预测模型,设计基于任务运行时间预测模型的并行图划分方法,从而有效解决计算节点的负载均衡问题.实验结果表明,与基于BMC图划分策略的最大团并行识别算法相比,该算法具有更高的求解效率,可取得近似线性的加速比.     

基于物理特性的光伏电池建模仿真及验证

提出了一种基于光伏电池物理特性的数学模型,并在Matlab/Simulink环境下建立了仿真模型。仿真结果表明,所提出的数学模型能很好地模拟光伏电池的特性。以此光伏电池模型为基础,建立了光伏电池最大功率点跟随系统的仿真模型,仿真结果验证了此光伏电池模型的正确性,为实际应用中,光伏电池的输出可靠性提供了新的解决思路。