I&#x;k Bier  Ralf W. Seifert 《Production and Operations Management》2017,26(12):2266-2286

We consider a manufacturer without any frozen periods in production schedules so that it can dynamically update the schedules as the demand forecast evolves over time until the realization of actual demand. The manufacturer has a fixed production capacity in each production period, which impacts the time to start production as well as the production schedules. We develop a dynamic optimization model to analyze the optimal production schedules under capacity constraint and demand‐forecast updating. To model the evolution of demand forecasts, we use both additive and multiplicative versions of the martingale model of forecast evolution. We first derive expressions for the optimal base stock levels for a single‐product model. We find that manufacturers located near their market bases can realize most of their potential profits (i.e., profit made when the capacity is unlimited) by building a very limited amount of capacity. For moderate demand uncertainty, we also show that it is almost impossible for manufacturers to compensate for the increase in supply–demand mismatches resulting from long delivery lead times by increasing capacity, making lead‐time reduction a better alternative than capacity expansion. We then extend the model to a multi‐product case and derive expressions for the optimal production quantities for each product given a shared capacity constraint. Using a two‐product model, we show that the manufacturer should utilize its capacity more in earlier periods when the demand for both products is more positively correlated.  相似文献   

    

Fleur G. GOMMANS  Nicole W.H. JANSEN  Dave STYNEN  IJmert KANT  Andries de GRIP 《International labour review / International Labour Office》2017,156(3-4):525-548

Based on a sample of older workers from the Maastricht Cohort Study, the authors investigate the prevalence and dynamics of self‐reported under‐skilling and its effects on workers' need for recovery, their risk of losing employment and their retirement intentions over a two‐year period. They find that being under‐skilled is associated both with higher levels of need for recovery over time and with the risk of losing employment, but not with early retirement intentions. To achieve sustainable employment, they argue, the course of under‐skilling should be monitored throughout workers' careers, enabling timely interventions to avoid its negative consequences.  相似文献   

    

Peter B. BERG  Mary K. HAMMAN  Matthew M. PISZCZEK  Christopher J. RUHM 《International labour review / International Labour Office》2017,156(3-4):495-523

A substantial portion of Germany's workforce will soon retire, making it difficult for businesses to meet their human capital needs; training older workers may help to manage this demographic transition. The authors therefore examine the relationships between employer‐provided training programmes, wages and retirement among older workers. They find that when establishments offer special training programmes targeted at these workers, women – especially low‐paid women – are less likely to retire, possibly because of consequent wage growth. Their results suggest that such targeted training can indeed play an important role in retaining low‐wage older women and advancing their careers.  相似文献   

    

Brett L. M. Levy  Lauren Collet-Gildard  Thomas C. Owenby 《Social Studies》2017,108(2):39-54

Researchers have found that when young people participate in discussions of controversial political issues, they often become more politically engaged and informed (Hess, 2009 Hess, Diana E. (2009). Controversy in the classroom: The democratic power of discussion. New York, NY: Routledge.[Crossref] , [Google Scholar]). Nonetheless, some educators avoid fostering such discussions because they can become heated and distract from academic learning (Hess, 2002 Hess, Diana E. (2002). Discussing controversial public issues in secondary social studies classrooms: Learning from skilled teachers. Theory &; Research in Social Education, 30(1), 10–41.[Taylor &; Francis Online] , [Google Scholar]). Presidential elections, including the highly publicized debates, provide substantial material for discussions of major national and international issues, but no published research has examined how educators can leverage these events to generate productive civic learning experiences. In this article, we analyze data collected in seven high school classrooms during the 2012 presidential election to examine the challenges and opportunities associated with generating substantive, dynamic discussions of presidential debates. Our findings indicate that students enjoyed learning about candidates' different perspectives and that certain strategies were especially helpful for fostering substantive discussions: (a) scaffolding students' preparation for discussion; (b) providing opportunities for students to address open-ended questions; (c) redirecting students' engagement in competitive, interpersonal dynamics to learning about public issues; and (d) countering students' partisan tendencies. We discuss implications for practice and research and present a conceptual framework for generating dynamic, substantive democratic discussions.  相似文献   

    

Sarah M. Mead  Cheryl R. Ellerbrock  Bárbara C. Cruz 《Social Studies》2017,108(2):72-77

Contemporary global issues can be examined through the lens of modern photographic art. In an effort to prepare global-ready graduates, this article explores the pressing problems of environmental degradation, urbanization, and homelessness through the work of three contemporary artists. Illustrative works, suggested approaches, and curriculum resources are provided.  相似文献   

    

Christopher C. Martell  Kaylene M. Stevens 《Social Studies》2017,108(6):249-260

In this interpretive case study the researchers examined the beliefs of 13 self-identifying race-conscious secondary social studies teachers from diverse racial or ethnic, gender, and school-context backgrounds. The researchers found that the teachers' beliefs and views of practice were generally aligned with the main assertions of critical race theory. The teachers described their personal and professional experiences as a major influence on their race-conscious beliefs and views of practice. Moreover, teachers in diverse contexts described having to learn how to navigate the different racial experiences of the students in their classrooms, while teachers in racially segregated contexts (predominately White, Black, or Latino) emphasized the importance of teaching their students about others. Finally, despite the teachers' regular integration of race-related issues into their required and elective courses, they expressed a desire to have more opportunities to teach about race.  相似文献   

    

Stephanie A. Wiebe  Susan M. Johnson  Melissa Burgess Moser  Tracy L. Dalgleish  Giorgio A. Tasca 《Journal of marital and family therapy》2017,43(2):213-226

Emotionally Focused Couple Therapy (EFT), an evidence‐based couple therapy (Johnson, Hunsley, Greenberg, & Schindler, 1999), strives to foster lasting change through the creation of secure attachment bonds in distressed couples. Although studies have demonstrated lasting change in follow‐up (Wiebe et al., in press), research is needed to investigate predictors of long‐term outcomes. Our goal was to investigate predictors of long‐term outcomes in relationship satisfaction. Relationship satisfaction was assessed across 24 months in a sample of 32 couples who received an average of 21 EFT sessions. Decreases in attachment avoidance were most predictive of higher relationship satisfaction across follow‐up. These findings support the theoretical assumption that EFT helps couples foster lasting change in relationship satisfaction through the facilitation of secure attachment bonds.  相似文献   

    

Younghee Lim  Elaine M. Maccio  Trey Bickham  William F. Dabney 《Social Work Education》2017,36(7):809-822

Previous research has found service-learning in undergraduate social policy courses to increase students’ knowledge, skills, values, and competence. The present study utilized a sample of 60 graduate-level social work students who participated in a research-based service-learning (RBSL) project that involved collecting and analyzing data about the extent of payday loan use among bankruptcy filers and reporting results to community partners. Quantitative findings revealed significant increases in students’ personal social responsibility. Qualitative findings shed light on growth in personal social responsibility, civic awareness, policy advocacy, and personal values. Suggestions for future studies using RBSL pedagogy to teach social policy are discussed.  相似文献   

    

Scott W. Semenyna  Doug P. VanderLaan  Lanna J. Petterson  Paul L. Vasey 《Journal of sex research》2017,54(8):1077-1084

Previous research established that male androphilia (i.e., sexual arousal and attraction to adult males) clusters in families. Some studies find that male androphilia clusters in both the paternal and maternal lines, while others find that it clusters only in the latter. Most of the research investigating the familial nature of male androphilia has taken place in Western cultural contexts that are problematic for such research because they are characterized by low fertility. To address this, our previous work has examined familial patterning of male androphilia in Samoa, a high-fertility population in which androphilic males are readily identified due to their public status as fa’afafine (a third gender category). Building on this work, the present study replicated the familial nature of male androphilia in Samoa using a sample size that was ~122% larger than the one we previously employed (N = 382, M ±SD age: 29.72 years ±10.16). Samoan fa’afafine had significantly more fa’afafine relatives in their maternal and paternal lines compared to Samoan gynephilic males (p < .001). The prevalence of male androphilia was equivalent across both the paternal and maternal lines (all p > .15). The revised prevalence estimate of male androphilia in Samoa falls between 0.61% and 3.51%.  相似文献   

    

Amanda M. Pollitt  Stephen T. Russell 《Journal of marriage and the family》2017,79(5):1278-1294

Bisexual youth are at elevated risk for depression when compared with lesbians and gay men. Research on bisexual stigma suggests that these youth are uniquely vulnerable to stress related to sexual identity disclosure. Depression associated with this stress may be buffered by social support from parents and friends. We examined the differential influence of social support from parents and friends (Child and Adolescent Social Support Scale) on the relation between disclosure stress (LGBTQ Coming Out Stress Scale) and depressive symptoms (Beck Depression Inventory) and differences by gender in a sample of cisgender bisexual youth (N = 383) using structural equation modeling. Parental support buffered the association between stressful disclosure to family and depressive symptoms, especially for bisexual men; bisexual women seemed not to benefit from such support when disclosure stress was high. This nuanced examination elucidates the ways family members and clinicians can best support bisexual youth sexual identity disclosure.  相似文献