Developmental Trajectories and Predictors of Social Exclusion Among Older Koreans: Exploring the Multidimensional Nature of Social Exclusion

The purpose of this paper was to investigate the developmental patterns of social exclusion among older Koreans over time. In addition, we identified the significant determinants that may increase the risk of social exclusion among older Koreans. The analyses were based on the panel data from the Korean Longitudinal Study of Ageing and included older adults from 2008 to 2012 (N?=?24,074) for the final analysis. Social exclusion was categorized into four different sub-dimensions: financial, social relational, social cultural, and emotional. The analysis was based on a semi-parametric group-based approach followed by multinomial logistic regression. The results showed considerable variations and different developmental trajectories by the social exclusion sub-dimensions among older Koreans; in particular, the results showed that being older, male, and less educated were significant indicators of social exclusion. This study adds to the limited body of literature on longitudinal studies of social exclusion among older Koreans, and the results will help develop interventions for older Koreans who are socially isolated.

     

A Probabilistic Transmission Model to Assess Infection Risk from Mycobacterium Tuberculosis in Commercial Passenger Trains

The objective of this article is to characterize the risk of infection from airborne Mycobacterium tuberculosis bacilli exposure in commercial passenger trains based on a risk‐based probabilistic transmission modeling. We investigated the tuberculosis (TB) infection risks among commercial passengers by inhaled aerosol M. tuberculosis bacilli and quantify the patterns of TB transmission in Taiwan High Speed Rail (THSR). A deterministic Wells‐Riley mathematical model was used to account for the probability of infection risk from M. tuberculosis bacilli by linking the cough‐generated aerosol M. tuberculosis bacilli concentration and particle size distribution. We found that (i) the quantum generation rate of TB was estimated with a lognormal distribution of geometric mean (GM) of 54.29 and geometric standard deviation (GSD) of 3.05 quantum/h at particle size ≤ 5 μm and (ii) the basic reproduction numbers (R₀) were estimated to be 0.69 (0.06–6.79), 2.82 (0.32–20.97), and 2.31 (0.25–17.69) for business, standard, and nonreserved cabins, respectively. The results indicate that commercial passengers taking standard and nonreserved cabins had higher transmission risk than those in business cabins based on conservatism. Our results also reveal that even a brief exposure, as in the bronchoscopy cases, can also result in a transmission when the quantum generation rate is high. This study could contribute to a better understanding of the dynamics of TB transmission in commercial passenger trains by assessing the relationship between TB infectiousness, passenger mobility, and key model parameters such as seat occupancy, ventilation rate, and exposure duration.     

Children with challenging behaviour: past and present in the United Kingdom

The aim of this paper is to give a brief overview of the historical and current understanding of and care for children with learning difficulties who displayed challenging behaviour in the United Kingdom. It is clear that challenging behaviour is not a new phenomenon but has existed throughout the history of learning difficulty.     

Socioeconomic Status,Psychosocial Factors and Health in Urban Guyana

Abstract

This study seeks to understand the relationship between socioeconomic status (SES) and self-reported indicators of physical and mental health in an urban Third World context. The data come from a probability sample of 654 adult residents of Georgetown, Guyana. There is a significant inverse association between formal education and morbidity for four of the six measures of health status. In this research the extent to which self-concept, health behaviors, stress and social ties are linked to health status and SES, and can explain SES differences in health status is explored. Psychosocial factors, especially the self-concept measures (self-esteem and mastery) play a moderate role in accounting for educational differences in health status.     

Single‐Period Two‐Product Assemble‐to‐Order Systems with a Common Component and Uncertain Demand Patterns

We consider a single‐period assemble‐to‐order system that produces two types of end products to satisfy two independent and stochastic customer orders. Each type of product is used to fulfill a particular customer order and these two products share a common component. Furthermore, one customer may confirm her order before the other one, and the manufacturer needs to make a commitment immediately upon the receipt of each customer order on how many products to be delivered. We propose a model for optimizing the inventory and production decisions under the above ATO environment. We also extend our model to the situation where the manufacturer can fulfill the unsatisfied low‐priority demand using the left‐over inventories after fulfilling the high‐priority demand, in case the low‐priority customer arrives first. Numerical experiments are conducted, which provide some interesting insights on the impact of uncertain demand pattern.     

Optimal Bootstrap Sample Size in Construction of Percentile Confidence Bounds

In traditional bootstrap applications the size of a bootstrap sample equals the parent sample size, n say. Recent studies have shown that using a bootstrap sample size different from n may sometimes provide a more satisfactory solution. In this paper we apply the latter approach to correct for coverage error in construction of bootstrap confidence bounds. We show that the coverage error of a bootstrap percentile method confidence bound, which is of order O ( n ^−2/2) typically, can be reduced to O ( n ⁻¹) by use of an optimal bootstrap sample size. A simulation study is conducted to illustrate our findings, which also suggest that the new method yields intervals of shorter length and greater stability compared to competitors of similar coverage accuracy.     

Approximation Algorithms in Batch Processing

A polynomial approximation scheme for minimizing makespan in a batch processing system under dynamic job arrivals is presented. A lower bound of on the competitive ratio of any on-line algorithm is proved. This is matched by an on-line algorithm for the special case of unbounded machine capacity.     

Inventory placement problems in dynamic supply chains

Summary  In this paper a basic model for analyzing the inventory placement problem in a supply chain is developed. The problem will be studied for a capacitated, multi-stage supply chain facing a continuous, stochastic demand for a single period for a single product — a specialty item with a very short selling season. The objective is to maximize the probability of achieving a set profit level. We prove that finding an optimal stock investment at the stages entails solving a mixed binary integer linear program. We characterize properties of the stock investment, examine two interesting cases where the stock investments have a simple structure, and develop a branch and bound approach for solving the more general case.

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Zusammenfassung  In diesem Beitrag wird ein Grundmodell entwickelt, um das Problem der Lagerplatzierung in einer Lieferkette analysieren zu k?nnen. Das Problem wird für eine kapazitierte mehrstufige Lieferkette untersucht, wobei unterstellt wird, dass es um die Nachfrage nach einem einzigen Produkt für eine einzige Periode (einen Sonderartikel mit sehr kurzer Verkaufszeit) geht und diese Nachfrage stetig und stochastisch ist. Unter diesen Bedingungen soll die Wahrscheinlichkeit maximiert werden, ein vorgegebenes Gewinnniveau zu erreichen. Die Suche nach der optimalen Vorratsinvestition auf den Stufen der Lieferkette führt zur Formulierung eines gemischten ganzzahligen linearen Programmierungsproblems mit Bin?rvariablen. Die Eigenschaften der Bevorratungsinvestition werden charakterisiert, zwei interessante F?lle mit einer einfachen Struktur der Bevorratungsinvestition untersucht und ein Branch-and-Bound-Ansatz zur L?sung eines allgemeineren Problemfalls entwickelt.

     

Work Discrimination and Coping Strategies: Conceptual Frameworks for Counseling Lesbian,Gay, and Bisexual Clients

Two conceptual models are proposed in this article—one for work discrimination and the other for discrimination coping strategies pertaining to lesbian, gay, and bisexual workers. The work discrimination model includes 3 dimensions (formal vs. informal, potential vs. encountered, and perceived vs. real). The coping strategies model outlines methods that deal with potential and encountered discriminations. It includes vocational choice and work adjustment strategies; the latter are further categorized under identity management or discrimination management strategies.