Mixed integer (0–1) fractional programming for decision support in paper production industry

This paper presents an effective and efficient method for solving a special class of mixed integer fractional programming (FP) problems. We take a classical reformulation approach for continuous FP as a starting point and extend it for solving a more general class of mixed integer (0–1) fractional programming problems.To stress the practical relevance of the research we focus on a real-life application in paper production industry. The constantly advancing physical knowledge of large scale pulp and paper production did have a substantial impact on an existing DSS in which mixed integer (0–1) fractional programming is introduced. We show that the motivation to solve a real-life fractional programming problem can provide the basis for a new approach in a new context that has an added value of its own, even outside the given application area. We describe the main characteristics of the DSS, the necessity to develop a non-iterative solution procedure and demonstrate both the effectiveness and efficiency of the proposed approach from practical data sets.     

案例教学法在专业课教学中的应用与实践

案例教学法在应用型人才培养中发挥着重要作用,应用日益广泛,但实践应用方面尚有诸多需要研究和解决的问题。文章围绕案例教学中案例教学准备、小组讨论、课堂讨论、案例教学评价、案例教学条件保障5个环节对案例教学实践应用进行初步研究和探讨。     

Staff rostering in call centers providing employee transportation

We address the staff rostering problem in call centers with the goal of balancing operational cost, agent satisfaction and customer service objectives. In metropolitan cities such as Istanbul and Mumbai, call centers provide the transportation of their staff so that shuttle costs constitute a significant part of the operational costs. We develop a mixed integer programming model that incorporates the shuttle requirements at the beginning and end of the shifts into the agent-shift assignment decisions, while considering the skill sets of the agents, and other constraints due to workforce regulations and agent preferences. We analyze model solutions for a banking call center under various management priorities to understand the interactions among the conflicting objectives. We show that considering transportation costs as well as agent preferences in agent-shift assignments provides significant benefits in terms of both cost savings and employee satisfaction.     

A latent variable model for analyzing mixed longitudinal (k,l)-inflated count and ordinal responses

A random effects model for analyzing mixed longitudinal count and ordinal data is presented where the count response is inflated in two points (k and l) and an (k,l)-Inflated Power series distribution is used as its distribution. A full likelihood-based approach is used to obtain maximum likelihood estimates of parameters of the model. For data with non-ignorable missing values models with probit model for missing mechanism are used.The dependence between longitudinal sequences of responses and inflation parameters are investigated using a random effects approach. Also, to investigate the correlation between mixed ordinal and count responses of each individuals at each time, a shared random effect is used. In order to assess the performance of the model, a simulation study is performed for a case that the count response has (k,l)-Inflated Binomial distribution. Performance comparisons of count-ordinal random effect model, Zero-Inflated ordinal random effects model and (k,l)-Inflated ordinal random effects model are also given. The model is applied to a real social data set from the first two waves of the national longitudinal study of adolescent to adult health (Add Health study). In this data set, the joint responses are the number of days in a month that each individual smoked as the count response and the general health condition of each individual as the ordinal response. For the count response there is incidence of excess values of 0 and 30.     

Assessing the performance of variational methods for mixed logistic regression models

We present a variational estimation method for the mixed logistic regression model. The method is based on a lower bound approximation of the logistic function [Jaakkola, J.S. and Jordan, M.I., 2000, Bayesian parameter estimation via variational methods. Statistics & Computing, 10, 25–37.]. Based on the approximation, an EM algorithm can be derived that results in a considerable simplification of the maximization problem in that it does not require the numerical evaluation of integrals over the random effects. We assess the performance of the variational method for the mixed logistic regression model in a simulation study and an empirical data example, and compare it to Laplace's method. The results indicate that the variational method is a viable choice for estimating the fixed effects of the mixed logistic regression model under the condition that the number of outcomes within each cluster is sufficiently high.     

The Subpoena of Ethnographic Data

This essay outlines the author's experience of having his ethnographic data subpoenaed. It outlines the challenges of subpoena's to research, and suggests four solutions: (1) Apply for and utilize the National Institutes of Health certificate of confidentiality by asking health‐related questions over the course of one's research; (2) Establish a task force that articulates clear ethical guidelines for ethnographic research, with attention to the conditions wherein ethnographers can break confidentiality (and might also comply with subpoenas). These ethical guidelines should then be made clear to research subjects as a part of informed consent processes; (3) Demand that institutions (institutional review boards) that require confidentiality as a condition of research be required to defend that confidentiality through the office of the general counsel; (4) Socialize the cost of subpoenas, wherein scholars can be part of an insurance pool that will defend them in the event of a subpoena and thereby defend the general enterprise of ethnographic research.     

Experiences with systematic triangulation at the Global Environment Facility

Systematic triangulation may address common challenges in evaluation, such as the scarcity or unreliability of data, or the complexities of comparing and cross-checking evidence from diverse disciplines. Used to identify key evaluation findings, its application has proven to be effective in addressing the limitations encountered in country-level evaluation analysis conducted by the Independent Evaluation Office of the Global Environment Facility (GEF). These include the scarcity or unreliability of national statistics on environmental indicators and data series, especially in Least Developed Countries; challenges in evaluating the impacts of GEF projects; and inherent difficulties in defining the GEF portfolio of projects prior to the undertaking of the evaluation. In addition to responding to the need for further developing triangulation protocols, procedures and/or methodologies advocated by some authors, the approach offers a contribution to evaluation practice. This applies particularly to those evaluation units tasked with country-level evaluations in international organizations, facing similar constraints.     

Contingent Eclecticism

For more than a century, methodological diversity within the social sciences has been the source of recurrent paradigm wars, and no obvious winner seems to be in sight. The aim of this article is to explore the contingencies underlying this diversity. It is argued that the shared condition of complexity forces us to adopt a pragmatic perspective from which even relevant ontological and epistemological assumptions should be thought of as contextual rather than absolute. In particular, the extent to which social causality is perceived as stable and universal vs. dynamic and contextual and the extent to which research‐related reflexivity is an issue appear to set apart the different approaches. Towards the end of the article examples of methodological fit and misfit are provided to illustrate the relevancy of the “contingent eclecticism” observed in practice.     

解释冲突的公断(Ⅰ)——论利科对当代诠释学的贡献

在当代诠释学领域中,各种诠释学理论相互冲突,方法论与存在论之间的冲突就是其中之一。利科立足西方哲学传统,通过现象学、语义学与反思环节,对诠释学方法论与存在论之间的关系做出了公断,解答了解释的冲突。     

The embodied becoming of autism and childhood: a storytelling methodology

In this article I explore a methodology of storytelling as a means of bringing together research around autism and childhood in a new way, as a site of the embodied becoming of autism and childhood. Through reflection on an ethnographic story of embodiment, the body is explored as a site of knowledge production that contests its dominantly storied subjectivation as a ‘disordered’ child. Storytelling is used to experiment with a line of flight from the autistic-child-research assemblage into new spaces of potential and possibility where the becomings of bodies within the collision of autism and childhood can be celebrated.