Redundant configuration of automated flow lines based on “Industry 4.0”-technologies

Over the past decades, robots have been heavily used for flow lines to increase productivity and product quality and to relieve workers of repetitive and dangerous tasks. However, despite continuous improvement of robots, the occurrence of failures remains a significant challenge in the operation of automated flow lines. Due to the connection of the stations in a flow line via a material handling system, failures at one station can quickly lead to throughput losses due to blocking and starving of upstream and downstream stations, respectively. To some extent, these throughput losses can be reduced by installing buffers between the stations. However, the installation of buffers requires considerable investments and scarce factory space. Therefore, the minimization of the total number of buffers is one of the primary objectives in flow line planning. Due to the advances of manufacturing technologies that form the foundation of “Industry 4.0”, new solutions to reduce throughput losses caused by equipment failures open up. One solution is a redundant configuration, in which downstream stations automatically take over the operations of failed stations in the event of failure. The throughput loss in these situations mainly depends on the level of redundancy designed into the system. Based on existing methods for the design of automated flow lines, we present two line balancing formulations for the configuration of automated flow lines under consideration of redundancies. The first formulation aims at maximizing the lines’ level of redundancy. The second formulation aims at a balanced allocation of redundancies along the line. To evaluate the presented formulations, we compare the performance with an existing line balancing approach for automated lines. With respect to this approach, improvements of the throughput rate between 3 % and 7 % are achieved.     

The education of children in care and children in need: Who falls behind and when?

We seek to explain the development of the educational gap between children in “out‐of‐home care” (CLA), children deemed in social need (CIN), and other pupils. A cohort of 642,805 pupils aged 16 in 2013 was used to chart the educational progress of the full cohort, the CLA (n = 6,236), the CIN in 2012 or 2013 but not CLA (n = 20,384), and a sample individually matched with the CLA (n = 11,084). At age 7, attainment of the CLA and CIN was approximately 1 standard deviation lower than the cohort average and predicted attainment at 16. At this point, the persistent “CIN” (those with earlier and persistent needs) had the lowest attainment relative to others, and this declined further during secondary school. Those entering care before or during primary school had very low attainment at age 7, but their relative attainment did not decline. Attainment of CLA and CIN at age 16 likely reflects early environment, special educational needs, and poor relationships with secondary school. Policy, research, and intervention should focus on CIN as well as CLA, do so before entry to care, and take account of the onset of, and probable reasons for, educational difficulties.     

Instrumental variable estimation in ordinal probit models with mismeasured predictors

Researchers in the medical, health, and social sciences routinely encounter ordinal variables such as self‐reports of health or happiness. When modelling ordinal outcome variables, it is common to have covariates, for example, attitudes, family income, retrospective variables, measured with error. As is well known, ignoring even random error in covariates can bias coefficients and hence prejudice the estimates of effects. We propose an instrumental variable approach to the estimation of a probit model with an ordinal response and mismeasured predictor variables. We obtain likelihood‐based and method of moments estimators that are consistent and asymptotically normally distributed under general conditions. These estimators are easy to compute, perform well and are robust against the normality assumption for the measurement errors in our simulation studies. The proposed method is applied to both simulated and real data. The Canadian Journal of Statistics 47: 653–667; 2019 © 2019 Statistical Society of Canada     

Comparing the transpirational and shading effects of two contrasting urban tree species

Urban Ecosystems - Urban trees are getting increasing attention as a tool to mitigate urban heat island effects. A more functional and quantitative view of transpirational and shading effect,...     

Factors limiting SGM youths’ involvement in nonmetropolitan SGM community organizations

Sexual and gender minority (SGM) youths face risks due to growing up with stigmatized identities. SGM organizations minimize these risks by reducing isolation, promoting positive identity development, and providing access to supportive resources. However, nonmetropolitan SGM youths may have high risks with low access to SGM organizations. Little research has been conducted on nonmetropolitan SGM organizations. This study utilized in-depth interviews and open-ended survey items to explore the factors limiting SGM youths’ involvement in nonmetropolitan SGM organizations. Findings revealed three factors limiting involvement: accessibility, utility, and stigma. Implications for future research and practice with SGM youths are discussed.     

The role of identity in the 2015 Romanian shepherd protests

Shepherds have a particular place in the history and culture of Romania. For centuries they have had rights to graze their sheep in public pastures and manage their flocks using traditional methods. Changes at the national and European level have threatened this way of life and provoked protest, most recently in December 2015 over plans to limit sheepdog numbers and restrict winter grazing rights. This article draws on interviews with participating and non-participating shepherds to examine the motivations behind the protest action and its relation to their position in contemporary society. The findings suggest how marginalised groups in society are able to draw on folk histories and cultural identities in the formulation of contentious politics in defence of their interests. The post-communist setting of the protests also highlights the persistence of traditional practices during a period of social and political upheaval.     

Impact of client suicide on social workers and counselors

Recent studies on the impact of client suicide on mental health professionals focus on psychiatrists and psychologists, while,in the current mental health system in our country, most clients receive services from other clinicians. This research focuses on the impact of client suicide on social workers and counselors as well as organizational responses to client suicide/attempt. Data were collected via interviews and survey of 121 clinicians. Client suicide impacts clinicians adversely in many ways. Many participants felt their agency/practice could have done more to support them during post-suicide management. Data presented in this report have the potential to aid in the creation of needed workforce development initiatives.     

Client Experiences of Trauma-Informed Care in Social Service Agencies

This paper describes a qualitative study of individual client interviews (n?=?26) from four social service agencies to understand how clients experience trauma-informed care services and implementation challenges. We used the Fallot and Harris framework to explore client experiences of the five core concepts of trauma-informed care (safety, trustworthiness, choice, collaboration, and empowerment) using semi-structured interview questions with each client. The four agencies consisted of: refugees (n?=?4), substance abuse (n?=?8), older adults (n?=?12), and maternal/child health (n?=?2), and the agencies varied in size, service goals, and clientele. The results of the study suggest that clients’ experience of these concepts was shaped by the actions of other clients, and these experiences were either mitigated or hindered by actions of the agency employees. Agency policies either supported or enhanced their experiences as well. The results also suggest that it was challenging for agencies to provide for all of the trauma-informed care (TIC) concepts at the same time. We discuss the implications of these findings for social service delivery in a range of agency types. Future research should examine the effects of trauma-informed policies on client experiences of each TIC domain.     

Patchwork of promises: A critical analysis of immigration policies for unaccompanied undocumented children in the United States

In 2014, the United States saw a greater than 50% increase in the number of unaccompanied children from Mexico and Central America arriving at the U.S./Mexico border, and unaccompanied children continue to migrate to the United States in consistent numbers. The dramatic increase of 2014 exposed gaps in policies aimed at supporting unaccompanied children as they await legal adjudication. This paper begins with a historic review of immigration policies in the United States aimed at supporting unaccompanied migrant children. An analytic review is provided of existing immigration policies in the Department of Homeland Security and the Office of Refugee Resettlement, highlighting the competing paradigms created by missions of security‐focused policy versus child‐centred policy. A close examination of the values that influenced policy development in this area is included, along with a discussion of how social work practice can infuse elements of social justice into immigration policy reform. Areas for future research to reform immigration policy focused on supporting unaccompanied undocumented minors are highlighted.