The deterministic EPQ with partial backordering: A new approach

Several authors have developed models for the EOQ when only a percentage of stockouts will be backordered. Most of these models are complicated, with equations unlike those for the EOQ with full backordering. In this paper we extend work by Pentico and Drake [The deterministic EOQ with partial backordering: a new approach. European Journal of Operational Research 2008; in press] that developed equations for the EOQ with partial backordering that are more like those for the EOQ with full backordering to develop a comparable model for the EPQ with partial backordering.     

The moderating effects of home region orientation on R&D investment and international SME performance: Lessons from Korea

Drawing from the resource-based view, we investigate how firm and country combinations affect international SME performance. Using a sample of 2676 international Korean SMEs, we explore the relationships among SME R&D investment, home region orientation and financial performance. Results show that R&D investment has a horizontally inverted S-shaped relationship with performance reflecting cost leadership, stuck in the middle, and differentiation strategies. We also find that a home region orientation moderates the relationship between R&D investment and performance. Home region orientation positively moderates the relationship when R&D investment reflects cost leadership or differentiation but negatively moderates a stuck in the middle strategy.     

An Economic Model of Friendship: Homophily,Minorities, and Segregation

We develop a model of friendship formation that sheds light on segregation patterns observed in social and economic networks. Individuals have types and see type‐dependent benefits from friendships. We examine the properties of a steady‐state equilibrium of a matching process of friendship formation. We use the model to understand three empirical patterns of friendship formation: (i) larger groups tend to form more same‐type ties and fewer other‐type ties than small groups, (ii) larger groups form more ties per capita, and (iii) all groups are biased towards same‐type relative to demographics, with the most extreme bias coming from middle‐sized groups. We show how these empirical observations can be generated by biases in preferences and biases in meetings. We also illustrate some welfare implications of the model.     

老龄工人在组织变革期间的管理:三种模型的应用

基于西方相关文献,本文讨论了组织性结构变革与老龄工人的健康之间的关系.通过对三个健康模型的分析—失去工作模型、付出-回报模型和工作控制模型,探讨了组织性结构变革是否会对老龄工人的健康造成影响,并进一步解释了在不同模型下组织性结构变革通过什么样的方式影响老龄工人的身心健康.文章还分析了三种模型之间的关系和应用,描述了政府和雇主在工作场所发生变化的时候,可以采取的减轻老龄员工健康风险的三个不同方法.最后针对中国现状,提出通过工作岗位支持来帮助老龄员工延缓与年龄相关的工作方面的及来自养老金和劳动力市场方面的压力的建议.     

Spectral estimation for locally stationary time series with missing observations

Time series arising in practice often have an inherently irregular sampling structure or missing values, that can arise for example due to a faulty measuring device or complex time-dependent nature. Spectral decomposition of time series is a traditionally useful tool for data variability analysis. However, existing methods for spectral estimation often assume a regularly-sampled time series, or require modifications to cope with irregular or ‘gappy’ data. Additionally, many techniques also assume that the time series are stationary, which in the majority of cases is demonstrably not appropriate. This article addresses the topic of spectral estimation of a non-stationary time series sampled with missing data. The time series is modelled as a locally stationary wavelet process in the sense introduced by Nason et al. (J. R. Stat. Soc. B 62(2):271–292, 2000) and its realization is assumed to feature missing observations. Our work proposes an estimator (the periodogram) for the process wavelet spectrum, which copes with the missing data whilst relaxing the strong assumption of stationarity. At the centre of our construction are second generation wavelets built by means of the lifting scheme (Sweldens, Wavelet Applications in Signal and Image Processing III, Proc. SPIE, vol. 2569, pp. 68–79, 1995), designed to cope with irregular data. We investigate the theoretical properties of our proposed periodogram, and show that it can be smoothed to produce a bias-corrected spectral estimate by adopting a penalized least squares criterion. We demonstrate our method with real data and simulated examples.     

Moderators of the Relationship Between Physical Activity and Alcohol Consumption in College Students

Abstract

Objective: Among college students, several studies have found a positive relationship between physical activity and alcohol use. The current study tested gender, Greek status, and ethnicity as potential moderators of the physical activity-alcohol use relationship. Participants: Participants were college freshmen (n = 310) endorsing alcohol/drug use. Methods: Students completed questionnaires assessing a number of health behaviors. Results: Results indicated that gender and Greek status were significant moderators of the relationship between physical activity and alcohol consumption. There was a positive relationship between physical activity and alcohol use for men and Greeks, but not for females and non-Greeks. Conclusions: These findings suggest that exercise does not serve as a protective factor for any of the subgroups of college students studied and is positively associated with drinking among college students who are men and/or involved with the Greek system.     

Measuring precautionary wealth using cross-sectional data: the case of farm households

This study models and investigates the presence of precautionary wealth among farm households, something few studies have attempted. Using pooled farm-level data, we find that self-employed farm households accumulate more wealth. Precautionary savings is about 8% of total household wealth. In addition, we find that age, education, occupation, and operation size are important factors influencing wealth accumulation by US farm households.     

Social Work Faculty Development: An Exploratory Study of Non-Tenure-Track Women Faculty

Administrators of schools of social work are paying more attention to the changing roles and types of faculty in their institutions, particularly given the surge of non-tenure-track faculty in academia. This topic is timely as social work grapples with the divergent roles, structure, and demographic characteristics of non-tenure-track faculty compared to their tenured or tenure-track counterparts. This exploratory study presents data from non-tenure-track women faculty (N = 10) on how they experience professional development. In-depth, qualitative data was collected to answer the research question, What do faculty identify as the barriers, supports, and opportunities for professional development and job satisfaction? Results indicate that organizational climate and mentoring are barriers and facilitators of faculty development, and the subjective definition of faculty development varies.     

Family-based approach to the child welfare system: an integration of Bowen family theory concepts

The purpose of this article is to apply Bowen family systems theory to work with families involved in the child welfare system. An overview of family systems theory is provided, and then specific tenets of Bowen family systems theory are presented. The authors highlight incidents within the child welfare setting that can be conceptualized through Bowen family therapy terms and concepts. A case study is used to highlight how this theory could be applied in practice. Furthermore, recommendations for child welfare practice and policy implications are discussed, utilizing the lens of a Bowenian family systems approach.     

The Rhetoric of the State: Dependency and Control in a Malaysian–Indonesian Borderland Key Words:

This article examines dependency on cross-border labor and marriage along the international frontier in the Kelabit Highlands of Sarawak, Malaysia (Borneo) and some local efforts to restrict outsiders. The international border in this remote region of Borneo is highly permeable, and border-crossing activities, including seasonal migrant wage labor and cross-border marriage, are crucial both to the local political economy and to the reproduction of the Kelabit family and farm. This article explores the unique position of the Kelabit as they attempt to appropriate aspects of state power or use the rhetoric of state power in their efforts to maintain a status quo with regard to neighboring, and closely related, migrant workers from across the border.