Sequential procedures based on M-estimators with discontinuous score functions

Bounded-width sequential confidence intervals and sequential tests for regression parameter based on M-estimators are extended to the case where the score-functions generating the M-estimators have jump-discontinuities. In the context of the asymptotic normality of the stopping variable, for the confidence interval problem, it is observed that the jump-discontinuities induce a slower rate of convergence. The proofs of the main theorems rest on the weak convergence of some related processes and this is also studied.     

非同类企业竞争与合作策略收益模型及风险分析

在比较同类企业竞争策略模型与合作策略模型的基础上,讨论了价格的信息作用,分析了合作策略收益更大和风险并不随之增加的原因。然后以现代决策理念为出发点,探讨了企业最大利润与企业条件的关系,提出了与企业单位变动成本和生产能力条件相适应的合理最大利润的概念,对“理性企业的假设”赋予了“追求与企业条件相适应的合理最大利润”的新含义。据此设计了非同类企业产量分配函数,建立了适用性更广的非同类企业合作策略最佳收益模型,并给出了随市场价格变化的企业最佳应对策略。最后用1个算例来直观体现合作策略的优势。     

Maximizing Business Returns to Corporate Social Responsibility (CSR): The Role of CSR Communication

By engaging in corporate social responsibility (CSR) activities, companies can not only generate favorable stakeholder attitudes and better support behaviors (e.g. purchase, seeking employment, investing in the company), but also, over the long run, build corporate image, strengthen stakeholder–company relationships, and enhance stakeholders' advocacy behaviors. However, stakeholders' low awareness of and unfavorable attributions towards companies' CSR activities remain critical impediments in companies' attempts to maximize business benefits from their CSR activities, highlighting a need for companies to communicate CSR more effectively to stakeholders. In light of these challenges, a conceptual framework of CSR communication is presented and its different aspects are analyzed, from message content and communication channels to company- and stakeholder-specific factors that influence the effectiveness of CSR communication.     

创建佛山生态城市的几点思考

生态城市是城市发展的新理念和新趋向。创建佛山生态城市设想是:构建具有南亚热带城市风貌、绿地系统完善、人居环境舒适优美的城市生态景观,发展科技含量高、经济效益好、资源消耗低、环境污染少的现代生态农业和新型生态工业,形成富有时代气息、具有岭南特色、融入生态内涵的生态文化。并要以新理念为导向,以新规划为蓝图,以新一轮产业结构调整为契机,以新机制为保障,推进城市的生态转型和生态建设。     

超声振动车削参数对切削力的影响

为了探究超声振动车削（UVT）过程中刀具振动频率、振幅和切削速度3个参数对切削力的影响,课题组通过建立有限元模型,对高强度铝合金超声振动车削和普通车削（CT）过程进行了对比研究。首先,研究了切削区域的Mises应力分布的变化;其次,对切削区域温度和微观切屑形态进行了分析,从微观层面揭示UVT方法降低切削力和切削温度的机理;最后,分别研究了刀具振动频率、振幅和切削速度对UVT平均切削力的影响。研究表明：超声振动车削的有限元仿真结果与“刀具 工件接触比理论”一致;在一定的范围内,增大刀具振动频率或振幅以及降低切削速度的方法可以有效降低切削力。文中的研究显示合理的选择超声振动车削工艺参数可以降低切削力,改善高强度铝合金的制造工艺。     

A Robust Procedure in Nonlinear Models for Repeated Measurements

Nonlinear regression models arise when definite information is available about the form of the relationship between the response and predictor variables. Such information might involve direct knowledge of the actual form of the true model or might be represented by a set of differential equations that the model must satisfy. We develop M-procedures for estimating parameters and testing hypotheses of interest about these parameters in nonlinear regression models for repeated measurement data. Under regularity conditions, the asymptotic properties of the M-procedures are presented, including the uniform linearity, normality and consistency. The computation of the M-estimators of the model parameters is performed with iterative procedures, similar to Newton–Raphson and Fisher's scoring methods. The methodology is illustrated by using a multivariate logistic regression model with real data, along with a simulation study.     

Progressively censored tests for clinical experiments and life testing problems based on weighted empirical distributions

In the context of time-sequential studies, progressively censored tests for a simple regression model based on weighted empirical distributions are considered for ungrouped as well as grouped data situations. Early decision rules based on such tests are formulated. The asymptotic theory of the proposed tests rests on a construction of suitable empirical processes and their convergence (in distribution) to appropriate Gaussian functions. Critical values of the proposed test statistics are obtained by simulation, For a hypothetical example (of practical interest), a comparative study is made for the empirical powers and stopping times for some rival tests.     

Bayes estimators of the average failure rates

In the present paper we have proposed a Bayesian approach for making inferences from accelerated life tests which do not require distributional assumptions     

Inference on Overlap for Two Inverse Gaussian Populations: Equal Means Case

The inverse Gaussian distribution is often suited for modeling positive and/or positively skewed data (see Chhikara and Folks, 1989 Chhikara , R. S. , Folks , J. L. ( 1989 ). The Inverse Gaussian Distribution . New York : Marcel Dekker . [Google Scholar]) and presents an interesting alternative to the Gaussian model in such cases. We note here that overlap coefficients and their variants are widely studied in the literature for Gaussian populations (see Mulekar and Mishra, 1994 Mulekar , M. , Mishra , S. N. ( 1994 ). Overlap coefficients of two normal densities: equal means case . J. Japan. Statist. Soc. 24 : 169 – 180 . [Google Scholar], 2000 Mulekar , M. , Mishra , S. N. ( 2000 ). Confidence interval estimation of overlap: equal means case . Computat. Statist. Data Anal. 34 : 121 – 137 .[Crossref], [Web of Science ®] , [Google Scholar], and references therein for further details). This article studies the properties and addresses point estimation for large samples of commonly used measures of overlap when the populations are described by inverse Gaussian distributions. The bias and mean square error properties of the estimators are studied through a simulation study.     

基于ANSYS的异型挠性管板强度分析及优化

为确保某异型挠性预热器管板强度的安全性,利用ANSYS分析软件对其进行强度分析。由分析结果可知,管板的设计满足各个工况的强度要求,温度载荷对管板的应力强度和应力分布影响显著。由于管板的初始设计过厚,导致设计偏于保守。利用ANSYS提供的APDL语言编程参数化技术,针对此过大安全裕度的问题,对该换热器进行结构优化分析。分析结果表明,在满足强度的要求的前提下,管板厚度得到有效降低,由此节约管板材料将近32%,优化效果十分明显,实现了轻量化和经济性的目标,对工程设计研究具有一定的指导意义。