The EPQ with partial backordering and phase-dependent backordering rate

In previous work we established a closed-form optimal stocking strategy for an EPQ model with partial backordering at a constant rate β. Here we extend this work to allow for the possibility that the percentage of demand backordered will increase when production starts again. We show how our previous model can be adapted to find the optimal decision variable values for this new assumption and develop the condition that the initial value of β must meet for partial backordering to be optimal.     

Communicating risk to parents and those living in areas with a disaster history

This study explored how publics respond to risk communication in high probability but time-indeterminate natural disaster situations when parts of the area have been involved in a similar disaster before. An impending rockslide is expected to produce a tsunami in the fjord around Åknes in Norway. Waves may run up above sea level as high as 82 m or 269 ft. All residents (18 and older) of the four most threatened communities received a questionnaire to determine what they perceived to be useful risk information. Three hundred and eighty-two (43.6% of 875) responded. Results indicated that parents of children living within the tsunami risk zones perceived the risk information to be the most useful. Those who lived in communities that experienced a similar disaster in 1934 reported public meetings less useful than written or mediated information. Publics who lived in communities with such disaster history and those who were not parents posed special challenges in risk communication because they perceived information from the government agencies as lacking in usefulness. Therefore, committing the resources necessary to foster dialogues with a diversity of publics exposed to risk would be well served to fully understand the nature of risk communication responses, and to be able to save human lives.     

Building a statistical model to predict reactor temperatures

This paper describes the various stages in building a statistical model to predict temperatures in the core of a reactor, and compares the benefits of this model with those of a physical model. We give a brief background to this study and the applications of the model to rapid online monitoring and safe operation of the reactor. We describe the methods, of correlation and two dimensional spectral analysis, which we use to identify the effects that are incorporated in a spatial regression model for the measured temperatures. These effects are related to the age of the reactor fuel and the spatial geometry of the reactor. A remaining component of the temperature variation is a slowly varying temperature surface modelled by smooth functions with constrained coefficients. We assess the accuracy of the model for interpolating temperatures throughout the reactor, when measurements are available only at a reduced set of spatial locations, as is the case in most reactors. Further possible improvements to the model are discussed.     

WHITE ENROLLMENT IN NONPUBLIC SCHOOLS, PUBLIC SCHOOL RACIAL COMPOSITION, AND STUDENT PERFORMANCE

This research note presents preliminary research into the relationship between the racial composition of public schools in school districts and the percentages of white students in nonpublic schools in those districts. Specifically, we ask two questions: Is the enrollment of whites in non‐public schools associated with minority predominance in public schools? Is there an association between the enrollment of whites outside of the public school system and the academic performance of students in the public school system? Using two‐ and three‐level hierarchical linear models, we find that school districts that have more whites in nonpublic schools tend to contain public schools with larger percentages of minority students. Further, at both the school and individual levels, achievement test scores tend to be lower in districts in which white students tend to be enrolled outside of the public school system. In addition, the achievement gap between white and minority students tends to be greater in districts with relatively more students in nonpublic schools. These findings are consistent with the argument that the withdrawal of white students from the public school system is negatively related to academic achievement because it tends to concentrate minority students in public schools.     

Moving Beyond Housing: Service Implications for Veterans Entering Permanent Supportive Housing

As a result of efforts to end homelessness among U.S. veterans, more former service members are entering permanent supportive housing (PSH). While PSH has been successfully used to house homeless veterans, more research is needed about services beyond housing placement and retention. This study uses the Gelberg–Andersen behavioral model for vulnerable populations to determine associations between predisposing, enabling, and need characteristics and recent service use (i.e., services to satisfy basic needs, occupational development, financial, healthcare, mental health) among unaccompanied homeless veterans (N?=?126) entering PSH in Los Angeles. Among the significant findings, as indicated using univariable logistic regression models, were veterans who had incarceration histories were more likely to utilize basic needs services, compared to those without incarceration histories. Veterans who received an honorable discharge were more likely to utilize occupational development services, compared to veterans with other discharge statuses. Veterans who had a case manager were more likely to utilize mental health services than those without a case manager, while those who received social security were less likely to utilize mental health services compared to veterans who did not receive social security. Veterans who met criteria for a psychological disability and veterans who met criteria for probable PTSD were more likely to use basic needs services and mental health services than veterans who fell below these thresholds. Clinical implications for social workers including “equal access to services,” “enhancing economic stability,” “providing safe and affordable housing with trauma-informed services,” and “training service social workers to deliver well-informed linkages and services” are discussed.     

The Nature of Social Pasts and Their Use as Foundations for Situated Action

In this paper social pasts are considered to be foundations of everyday interpersonal life, including everyday situated action. We distinguish social pasts from culture by noting that the former involves recognition of specific joint acts and social placements while the latter involves recognition of ties to acts and placements in general. We further distinguish shared pasts–which refer to specific and previous joint acts or social placements that interactors constructed together–from common pasts–which refer to specific and previous joint acts or social placements that interactors constructed with others. We assess the importance of using either common or shared pasts in the course of completing and simplifying complex and everyday transactions so as to create an appearance of routine-ness in relation to constructing these acts.     

The right to be different: Multiculturalism and the racialization of scandinavian welfare politics; The case of Denmark

‘Multiculturalism’ as an influential ideology for structuring ethnic relations has become exposed to increasing critique also in the Scandinavian context. The paper discusses a racialized political debate, legislation, and institutional practices, taking Denmark as the prime example. An increasingly ‘dual welfare’ is becoming legitimized through a hegemonic culturalized language, consistently interpreting ‘the right to be different’ as ‘being different’, and ‘being different’ as being ‘non‐integrated’. In a society where public debate on ethnic and racial discrimination is less than rudimentary, tolerant claims of multiculturalist relativism are effectively turned upside down in the service of neo‐racism, the preachings of which are imperceptibly becoming adopted as the conventional wisdom. This calls for a discussion on ‘politics of recognition’ which brings the debate on the universalism and particularity out of the abstract, while focusing on the vicissitudes of contemporary democracy in a changing welfare state.