Shift scheduling for tank trucks

In this paper we deal with shift scheduling of tank trucks for a small oil company. Given are a set of tank trucks with different characteristics and a set of drivers with different skills. The objective is to assign a feasible driver to every shift of the tank trucks such that legal and safety restrictions are satisfied, the total working times of the drivers are within desired intervals, requested vacation of the drivers is respected and the trucks are assigned to more favored drivers. We propose a two-phase solution algorithm which is based on a mixed integer linear programming formulation and an improvement procedure. Computational results are reported showing that the algorithm is able to generate feasible schedules in a small amount of time.     

When do older adults become "disabled"? Social and health antecedents of perceived disability in a panel study of the oldest old

Disability carries negative social meaning, and little is known about when (or if), in the process of health decline, persons identify themselves as "disabled." We examine the social and health criteria that older adults use to subjectively rate their own disability status. Using a panel study of older adults (ages 72+), we estimate ordered probit and growth curve models of perceived disability over time. Total prevalent morbidity, functional limitations, and cognitive impairment are predictors of perceived disability. Cessation of driving and receipt of home health care also influence older adults 'perceptions of their own disability. A dense social network slowed the rate of labeling oneself disabled, while health anxiety accelerated the process over time, independent of health status. When considering perceived disability, the oldest old use multidimensional criteria capturing function, recent changes in health status and social networks, and anxiety about their health.     

Using words to network images: indexing and interaction strategies in a digital archive

Visual access to the content in digital archives extends the classical text search and list view of graphical user interfaces. Currently, there are several strategies employed to correlate images in the user interface of digital archives for semantic purposes. Some of the most useful strategies explore innovative techniques used to gain and execute metadata in a suitable manner. These approaches are elaborated on primarily in the context of scientific questions. Amidst these models, this article proposes a very simple strategy of networking images using only words. At present, this concept is realised at Zurich University of the Arts (ZHdK) through utilisation of the ‘Media Archive of the Arts’, an in-house, open source software product. It responds to user heterogeneity, the variety of intellectual genres and the multiplicity of media formats that are distinctive of an art academy such as ZHdK.     

Social capital and women's reduced vulnerability to HIV infection in rural Zimbabwe

Social capital—especially through its “network” dimension (high levels of participation in local community groups)—is thought to be an important determinant of health in many contexts. We investigate its effect on HIV prevention, using prospective data from a general population cohort in eastern Zimbabwe spanning a period of extensive behavior change (1998–2003). Almost half of the initially uninfected women interviewed were members of at least one community group. In an analysis of 88 communities, individuals with higher levels of community group participation had lower incidence of new HIV infections and more of them had adopted safer behaviors, although these effects were largely accounted for by differences in socio-demographic composition. Individual women in community groups had lower HIV incidence and more extensive behavior change, even after controlling for confounding factors. Community group membership was not associated with lower HIV incidence in men, possibly refecting a propensity among men to participate in groups that allow them to develop and demonstrate their masculine identities—often at the expense of their health. Support for women's community groups could be an effective HIV prevention strategy in countries with large-scale HIV epidemics.     

Psychologists’ roles in ending homelessness

Homelessness in the U.S. remains a pernicious social problem despite national coordinated efforts to end it. Psychologists are well positioned to address homelessness through direct service, advocacy, research, and policy work. Results of a survey of psychologist members (n?=?197) and student members (n?=?209) of the American Psychological Association highlighted activities they engaged in related to helping people who experience housing instability and showed psychologists are more compassionate toward those who experience homelessness than is the general public. Respondents suggested a number of factors that would encourage their greater involvement with homelessness issues including receiving more focused training, increased funding for services, and simply being asked by someone to help. Given the continued problem of homelessness, psychologists can play an important role in supporting those who are in this situation. Suggestions for increasing training and engagement of psychologists are discussed.     

A methodological approach to strategic petroleum reserves

Energy constitutes a small fraction of the production inputs in the economy, yet the rigidity imposed by the short and medium term inability to substitute energy with other production factors in case of an energy shortage, requires the establishment of safeguard mechanisms to ensure sufficient energy supply during an emergency. These safeguards usually take the form of strategic energy reserves. A methodological approach is presented here, relating the level of strategic petroleum reserves, the decision variable, with the costs associated with their storage and the economic losses incurred by an energy shortage. This approach is based on the use of a decision tree, to portray emergency scenarios. Each scenario, a branch of the decision tree, can be evaluated in terms of a cost function which includes the inventory procurement and maintenance cost and the shortage cost inflicted by a petroleum shortfall.     

Route first—Cluster second methods for vehicle routing

In this paper we consider route first—cluster second methods for the vehicle routing problem. Extensions to the basic method both to improve its effectiveness and to enable it to cope with practical constraints are described. Computational results are given for the method applied to standard vehicle routing problems drawn from the literature.     

When nature rebels: international migration, climate change, and inequality

We study climate change and international migration in a two-country overlapping generations model with endogenous climate change. Our main findings are that climate change increases migration; small impacts of climate change have significant impacts on the number of migrants; a laxer immigration policy increases long-run migration, aggravates climate change, and increases north–south inequality if climate change impacts are not too small; and a greener technology reduces emissions, long-run migration, and inequality if the migrants’ impact to overall climate change is large. The preference over the policies depends on whether the policy maker targets inequality, wealth, the environment, or the number of migrants.     

Intimate partner violence and Hurricane Katrina: predictors and associated mental health outcomes

This study sought to establish the prevalence and correlates of intimate partner violence (IPV) victimization in the 6 months before and after Hurricane Katrina. Participants were 445 married or cohabiting persons who were living in the 23 southernmost counties of Mississippi at the time of Hurricane Katrina. Data for this study were collected as part of a larger, population-based, representative study. The percentage of women reporting psychological victimization increased from 33.6% prior to Hurricane Katrina to 45.2% following Hurricane Katrina (p < .001). The percentage of men reporting psychological victimization increased from 36.7% to 43.1% (p = .01). Reports of physical victimization increased from 4.2% to 8.3% for women (p = .01) but were unchanged for men. Significant predictors of post-Katrina victimization included pre-Katrina victimization, age, educational attainment, marital status, and hurricane-related stressors. Reports of IPV were associated with greater risk of post-Katrina depression and posttraumatic stress disorder. Data from the first population-based study to document IPV following a large-scale natural disaster suggest that IPV may be an important but often overlooked public health concern following disasters.