The Flow Shop Scheduling Polyhedron with Setup Times

This paper addresses the problem of improving the polyhedral representation of a certain class of machine scheduling problems. Despite the poor polyhedral representation of many such problems in general, it is shown that notably tighter linear programming representations can be obtained for many important models. In particular, we study the polyhedral structure of two different mixed-integer programming formulations of the flow shop scheduling problem with sequence-dependent setup times, denoted by SDST flow shop. The first is related to the asymmetric traveling salesman problem (ATSP) polytope. The second is less common and is derived from a model proposed by Srikar and Ghosh based on the linear ordering problem (LOP) polytope. The main contribution of this work is the proof that any facet-defining inequality (facet) of either of these polytopes (ATSP and LOP) induces a facet for the corresponding SDST flow shop polyhedron. The immediate benefit of this result is that all developments to date on facets and valid inequalities for both the ATSP and the LOP can be applied directly to the machine scheduling polytope. In addition, valid mixed-integer inequalities based on variable upper-bound flow inequalities for either model are developed as well. The derived cuts are evaluated within a branch-and-cut framework.     

Appraising Cultural Identity in Career-Development Assessment and Counseling

Career-Development Assessment and Counseling (C-DAC) systematically bridges career theory and practice. Integrating differential, developmental, and phenomenological methods, the C-DAC model uses a comprehensive career assessment battery to help clients explore their roles, developmental stages and tasks, career attitudes and knowledge, values, and interests within their unique life contexts. The authors recommend elaborating the C-DAC model to formally appraise cultural identity in step one of the model and to consider cultural identity concerns throughout the C-DAC process. This should help counselors more clearly understand how cultural factors influence people's career development and vocational behavior.     

Interactions of land-use history and current ecology in a recovering “urban wildland”

Despite the highly disrupted nature of abandoned industrial sites, they have significant human and ecological value. Ecological recovery at such sites is determined by complex interactions between natural factors and anthropogenic influences. Here we describe the land-use history and ecology of a former industrial wasteland. The spatial and temporal distribution of human disturbance at the study site included early farming, clay mining, brick making and landfilling, activities which have had profound and lasting ecological impacts resulting in a diverse but highly disrupted successional mosaic. Understanding the postdisturbance ecological recovery at this site has required a knowledge of natural factors such as slope, soil types and bedrock geology and hydrology, coupled with a detailed knowledge of the land-use history. Compared to recovery trajectories from many types of natural disturbance, ecological change at this site has been slower and more variable. Understanding ecological history has been crucial in projecting future changes as well as in making wise decisions about use and management practices for the site.     

Planning for physical distribution

Traditionally under-managed and poorly represented in the decision taking hierarchy, the physical distribution function of many manufacturing companies has not been strong on long range planning. With its basic input, the plans of production and marketing activities, vulnerable to a host of fluctuating outside factors, and with the present economic situation making any kind of planning extremely difficult, planning for Physical Distribution activity must be cautious yet flexible in the coming decade.     

The Stratification of Emotions: Some Preliminary Generalizations*

Like all valued resources, positive and negative emotions are unequally distributed in a society and constitute an important basis of social stratification. In this article, a general conceptual scheme and a more specific theory of emotions are employed to offer a preliminary explanation of the dynamics of emotional stratification. This theory attempts to explain which specific positive and negative emotions will be aroused and distributed across the social class system as well as among members of differentially evaluated social categories. The theory emphasizes the importance of repression and subsequent attribution processes as central to understanding the nature, intensity, and distribution of negative emotions among individuals in lower social classes and devalued social categories. By viewing emotions as not just reactions to the unequal distribution of other resources but, rather, as a valued or punishing resource in their own right, it becomes possible to better understand how micro‐level dynamics occurring in face‐to‐face encounters are affected by, and have effects on, meso‐level and macro‐level social structures and their respective cultures. In particular, the distribution of emotions can help account for both the processes of legitimatization of macrostructures and, at the same time, de‐legitimization of, and collective action against, macrostructures. This analysis of emotions questions much recent theorizing and commentary, often within postmodern analysis, about the authenticity of people’s emotions in contemporary society. The stratification of emotions is as real as inequality in money and power, and it has significant effects on the dynamics of human societies.     

Documenting the quick and the dead: a study of suicide case files in a coroner's office

In keeping with recent critiques of literature on the body and the life course, the argument of this paper is that social identities can, to a certain extent, be constructed post‐mortem and in the absence of a living body. The authors make this case with reference to a sociological autopsy study of a hundred suicide case files in a coroner's office in a medium‐sized British city. The research draws on ethnographic approaches to the study of documents. There is discussion of some of the diverse artefacts in the coroners' files: medical reports, witness statements and suicide notes. The identity work revealed in these sources is as much about the living as the dead and is especially bound up in the process of avoiding blame.     

Digital Sociology: Emergent Technologies in the Field and the Classroom

In this essay, I use my own research experiences to address a critical intersection between technology and sociology. I suggest that thinking reflexively about technology might enhance both how sociologists do research and how they teach about it.     

Source Attribution of Food-Borne Zoonoses in New Zealand: A Modified Hald Model

A Bayesian approach was developed by Hald et al .^{( 1 )} to estimate the contribution of different food sources to the burden of human salmonellosis in Denmark. This article describes the development of several modifications that can be used to adapt the model to different countries and pathogens. Our modified Hald model has several advantages over the original approach, which include the introduction of uncertainty in the estimates of source prevalence and an improved strategy for identifiability. We have applied our modified model to the two major food-borne zoonoses in New Zealand, namely, campylobacteriosis and salmonellosis. Major challenges were the data quality for salmonellosis and the inclusion of environmental sources of campylobacteriosis. We conclude that by modifying the Hald model we have improved its identifiability, made it more applicable to countries with less intensive surveillance, and feasible for other pathogens, in particular with respect to the inclusion of nonfood sources. The wider application and better understanding of this approach is of particular importance due to the value of the model for decision making and risk management.