Evaluation of scheduling strategies for a dynamic job shop in a tool-shared,flexible manufacturing environment

A two-phase approach is used to examine the impact of job scheduling rules and tool selection policies for a dynamic job shop system in a tool-shared, flexible manufacturing environment. The first phase develops a generalized simulation model and analyses 'simple' job scheduling rules and tool selection policies under various operating scenarios. The results from this investigation are then used to develop and analyse various bi-criteria rules in the second phase of this study. The results show that the scheduling rules have the most significant impact on system performance, particularly at high shop load levels. Tool selection policies affect some of the performance measures, most notably, proportion of tardy jobs, to a lesser degree. Higher machine utilizations can be obtained at higher tool duplication levels but at the expense of increased tooling costs and lower tool utilization. The results also show that using different processing time distributions may have a significant impact on shop performance.     

环状区域的车辆路径方案生成系统及优化模型

针对顾客满足环状区域分布的车辆路径问题(VRP),以大幅度地缩减问题求解的状态空间为突破口,引入人工智能和运筹学理论,提出求解这类特殊车辆路径问题的两阶段方法.第1阶段考虑行车时间和车载容量,提出带有控制策略的深度优先搜索算法自动生成备选的车辆路径方案集合.第2阶段将此备选方案集合归结为整数规划模型.采用VB6.0编程语言构建了车辆路径方案生成系统,并实现该系统与运筹学求解软件lindo的集成.通过案例验证了上述方法及自动求解系统的有效性.该项研究为解决环状配送区域的车辆路径问题这一难题提供了新方法.     

Bureaucracy Redux: Management Reformism and the Welfare State

Bureaucratic discretion is a fundamental feature of social provision,one that presents enduring difficulties for management. In general,management reform has taken two, divergent paths. One, utilizingthe familiar public bureaucratic model, seeks to control discretionthrough hierarchical command structures and standardization.The other, utilizing decentralization and privatization, regulatesand relocates discretion, using incentive structures associatedwith market or quasi-market institutions. However, it may bethat discretion will prove to be as problematic for the newpublic management (NPM) as it was for the old. This articleoffers a critical political history of management reformism,reviewing efforts to reorganize the public welfare provisionby applying new public management models to old public bureaucracyproblems. It considers the dynamics of bureaucratic discretionand reform not only as a problem of public management but aspart of the contested politics of social policymaking.     

NEGOTIATING CONTINUITY: Family and Religious Socialization for Second-Generation Asian Americans

This article examines second-generation Asian Americans' explanations of the significant influences on their own religious identities. Data include interviews (N = 73) with college-aged Asian Americans from different religious traditions and ethnic backgrounds. Respondents viewed families as the most significant influence on current religiosity. Mothers and fathers were mentioned most often, followed by extended kin, siblings, and relatives, who acted as what we call "reinforcers,""substitutes," or "contrasts" to the roles that parents played in religious socialization. These roles occurred along two religious configurations within families: heterogeneous or homogeneous degrees of religious commitment and religious affiliation. Directions for future research and contributions to the religious transmission literature follow.     

Stancetaking and the joint construction of zine producer identities in a research interview

This article examines the construction of zine producer identities (self and other) during a research interview. Zines are self‐published texts that circulate in mainly underground communities. In this study, I draw on dialogic understandings of the notion of ‘stance’ to show how a zine producer accomplishes a situated identity performance in the interview that also functions as an interdiscursive move in a larger conversation about the role Do‐It‐Yourself (DIY) ethics should play in zine communities. Specifically, I show how this speaker displays stances in relation to recognizable social types within zine communities but also the canonical stances associated with these social types. I unpack the features that work in support of this stancetaking, including discourse markers, constructed dialogue, referring terms, and prosodic cues. The analysis also foregrounds how the interviewer's turns contributed to these emergent stance displays, which furthers our understanding of the dynamic social context of the research interview.     

Spatial Patterns of Fertility Transition in Indian Districts

The article explores the dynamics of Indian fertility at the district level using a child‐woman index developed from the four Indian censuses, 1961 to 1991. It employs statistical and geostatistical techniques to assess fertility change across districts and periods. Fertility decline is evident in every region, but sizable regional differentials exist. A cluster analysis of fertility profiles indicates that a clear spatial pattern of fertility in India has emerged and the pattern intensified because of the process of fertility decline.     

A biclustering algorithm for binary matrices based on penalized Bernoulli likelihood

We propose a new biclustering method for binary data matrices using the maximum penalized Bernoulli likelihood estimation. Our method applies a multi-layer model defined on the logits of the success probabilities, where each layer represents a simple bicluster structure and the combination of multiple layers is able to reveal complicated, multiple biclusters. The method allows for non-pure biclusters, and can simultaneously identify the 1-prevalent blocks and 0-prevalent blocks. A computationally efficient algorithm is developed and guidelines are provided for specifying the tuning parameters, including initial values of model parameters, the number of layers, and the penalty parameters. Missing-data imputation can be handled in the EM framework. The method is tested using synthetic and real datasets and shows good performance.     

The 'demon' problem of Youden: Exponential case

We consider the problem of finding the probability of a sample mean falling above the (n - k)th-order statistic in a random sample of size n. Explicit expressions are obtained for the exponential distribution. Some applications that pertain to testing for outliers and goodness of fit are given.