SOLVING A COMBINED PART-SELECTION,MACHINE-LOADING,AND TOOL-CONFIGURATION PROBLEM IN FLEXIBLE MANUFACTURING SYSTEMS*

Loading too many or too few copies of tools may result in waste of tool magazine slots and unnecessary machine shutdowns. This is a consequence of not integrating the tool-configuration problem with other flexible manufacturing system (FMS) planning problems. Solving part-selection, machine-loading and tool-configuration problems independently may cause entire solutions to be infeasible. We propose both an approach to the explicit formulation of tool configuration problems and the simultaneous solution of part-selection, machine-loading and tool-configuration problems. We developed and solved sequentially some associated bicriteria models sequentially. We also discussed the effects of considering some secondary objectives on system performance and described the concepts of critical magazine size and critical machining time using an example problem. Unnecessary allocation and under-use of tool magazine capacity and machining time could be reduced by considering the critical magazine size and machining time. Finally, we suggest using a method based on Lagrangian relaxation for solving large size problems.     

The Design of a Knowledge-Based Decision Support System to Support the Information Analyst in Determining Requirements

Decision support system (DSS) researchers and designers continue to look for unstructured organizational tasks where there is a critical need for intelligent computer-based support. One such decision task is information requirements determination. Requirements determination is recognized as the most crucial phase of the systems development life cycle. Unfortunately, most methodologies and CASE tools focus only on how to specify the requirements once they are determined. There is very little computer support for the process of determining requirements. This paper discusses the conceptual design and development of a knowledge-based DSS to support information analysts in the critical decision task of determining requirements for the design of effective information systems. The expert modeling support system has the expertise to assist the analyst in studying the organization as a whole and in modeling the system under study in the context of the overall organization's goals and needs. The focus of the paper is on the problems associated with building the knowledge base component of the intelligent decision support system. A prototype implementation of the system is described.     

Some Comments on the Validity of EOQ Formula under Inflationary Conditions

In an earlier issue of Decision Sciences, Jesse, Mitra, and Cox [1] examined the impact of inflationary conditions on the economic order quantity (EOQ) formula. Specifically, the authors analyzed the effect of inflation on order quantity decisions by means of a model that takes into account both inflationary trends and time discounting (over an infinite time horizon). In their analysis, the authors utilized two models: Current-dollars model and Constant-dollars model. These models were derived, of course, by setting up a total cost equation in the usual manner then finding the optimum order quantity that minimizes the total cost. Jesse, Mitra, and Cox [1] found that EOQ is approximately the same under both conditions; with or without inflation. However, we disagree with the conclusion drawn by [2] and show that EOQ will be different under inflationary conditions, provided that the inflationary conditions are properly accounted for in the formulation of the total cost model.     

Reactive, anxious and possessive forms of jealousy and their relation to relationship quality among heterosexuals and homosexuals

The present study examined the relationship between relational quality and three different types of jealousy-reactive, anxious and possessive jealousy. The sample consisted of 76 gay men, 79 lesbians, 70 heterosexual women and 70 heterosexual men. Findings show that different types of jealousy affect relationship quality differently and do so differently for homosexuals and heterosexuals. Among heterosexuals and especially gay men--but not among lesbians--anxious jealousy was negatively related to relationship quality. In contrast, among heterosexuals--but not among gay men or lesbians--reactive jealousy was positively related to relationship quality. The present study shows that distinguishing between different types of jealousy is necessary to entangle the diverse effects of jealousy on the quality of homosexual and heterosexual relationships.     

Forced online: push factors of internet sexuality: A preliminary study of online paraphilic empowerment

Online sexual behavior may be more completely explained by integrating a Pull Factor analysis, centering on the characteristics of the Internet that make it an appealing outlet for sexuality (e.g., "Triple A Engine") and a Push Factor analysis, centering on characteristics of the offline world that disallow fulfillment of sexual desires. This new framework is utilized in explaining paraphilic (unconventional) sexualities online. Because paraphilics are members of highly concealable, horizontal and rare sexual minorities, they are pushed online by mainstream society. Online, paraphilics interact with similar others, and through lurking, re-learning and self-disclosing, may become sexually empowered. Clinical ramifications of attainment of positive sexual-social identity via empowerment are discussed, as are possible affects on public policy.     

Resource Flexibility Issues in Multistage Manufacturing

We test the situational impact of two types of resource flexibility, machine flexibility and labor flexibility, in a material requirements planning (MRP)-driven production system. Machine flexibility has not been treated in prior multistage research, only labor flexibility. Machine flexibility is closely related to a plant's positioning strategy. A process-focused plant opts for considerable machine flexibility by choosing general-purpose equipment. Resource flexibility, if effective, can be an attractive alternative to two other types of buffers, inflated inventories and costly capacity cushions. Our simulation results, using factor settings established earlier by a panel of managers, show that resource flexibility is indeed an effective buffer against uncertainties such as end-item demand variability, capacity bottlenecks, equipment failures, and yield losses. Machine flexibility is especially helpful in environments characterized by high uncertainties, tight capacities, and large lot sizes. Worker flexibility has a similar, but less dramatic, impact. Benefits are most striking with customer service, rather than with inventory or labor productivity. Finally, we show that simultaneous introduction of both machine and labor flexibility yields only marginal improvements over either kind of flexibility alone.     

Multi-Item Grouping Algorithm Yielding Near-Optimal Logistics Cost

This article describes an algorithm used to formulate an inbound consolidation strategy when multi-items are replenished in groups and when total logistics cost is to be minimized. The importance of this algorithm is threefold (1) no optimal procedure exists for grouping multi-items when minimizing total logistics cost, (2) a complete enumeration of all possible groups (from which the optimal grouping set can be identified) is impractical due to the combinatorial nature of the grouping problem, and (3) no other heuristics have been developed that adequately reflect shipping cost in the analysis like this one does. We report the experience of using this algorithm to group and reorder 75 selected ensembles containing a total of 517 inventory items of a retail merchandising firm.     

Evaluating social investment in disability policy

Disability policy in European countries is displaying a shift towards social investment: increasing human capital and access to the labour market. The reasoning that underlies this transition is that disabled persons would benefit from mainstream employment, but are impeded in traditional policy by deficiencies in labour supply and demand. However, the shift towards more activating policies in many countries is accompanied by a decline in social protection. It is unclear whether social investment may effectively promote the employment chances of disabled persons within this context. The present research examines this question through a quantitative, cross-sectional, multilevel analysis on microdata from 22 EU countries. Our findings suggest greater activation to predict lower employment chances, while reducing passive support shows mixed effects. Conversely, measures for facilitation in daily life predict greater employment chances, as do measures for sheltered work. These findings raise questions over the value of social investment for disabled persons—and underline the need to overcome broader barriers in the labour market and in society.     

Legal Consciousness in Action: Lay People and Accountability in the Jury Room

Qualitative Sociology - This paper argues that lay people’s legal consciousness, defined as how they experience and interpret the law and legal meanings, can be studied by observing natural...     

Best practices for online Canadian prenatal health promotion: A public health approach

Background

Prenatal health promotion provides information regarding pregnancy risks, protective behaviours and clinical and community resources. Typically, women obtain prenatal health information from health care providers, prenatal classes, peers/family, media and increasingly, Internet sites and mobile apps. Barriers to prenatal health promotion and related services include language, rural/remote location, citizenship and disability. Online public health platforms represent the capacity to reach underserved women and can be customised to address the needs of a heterogeneous population of pregnant women.