Inverse Combinatorial Optimization: A Survey on Problems, Methods, and Results

Given a (combinatorial) optimization problem and a feasible solution to it, the corresponding inverse optimization problem is to find a minimal adjustment of the cost function such that the given solution becomes optimum.Several such problems have been studied in the last twelve years. After formalizing the notion of an inverse problem and its variants, we present various methods for solving them. Then we discuss the problems considered in the literature and the results that have been obtained. Finally, we formulate some open problems.     

Seventh-Grade Social Studies versus Social Meliorism

The Wake County Public School System (WCPSS), in the state of North Carolina, has gone through considerable recent effort to revise, support, and assess their seventh-grade social studies curriculum in an effort to serve three goals: comply with the Common Core State Standards (Common Core), comply with the North Carolina Essential Standards (Essential Standards), and create a curriculum that best serves students. Meanwhile, the curriculum theory of social meliorism was conceived of over a century ago. Since its inception it has influenced curriculum development and provided a foundation for many other curriculum theories that all start from an assumption that social meliorism holds to an accepted truth that the purpose of education is to improve society and address its injustices. Given contemporary discussions about how to achieve social justice, this is a philosophy that seems particularly meaningful when thinking about the ways that schools can help to accomplish the goals of social justice. I intend to investigate the seventh-grade social studies curriculum of WCPSS in 2014 and juxtapose it with the goals and ideals of social meliorism, determine how well the curriculum addresses the goals of that curriculum theory, and make suggestions for how a social meliorist might suggest modifying the curriculum to better serve the needs of society.     

Die Rettung von Juden im Zweiten Weltkrieg

The rescue of Jews in WWII was in many respects extraordinary. For theories of action in the social sciences, these acts pose the challenge to explain pro-social behavior in the face of great risks. Whereas the overwhelming bulk of the literature points towards a specific altruistic personality or identity, rational choice explanations emphasize the significance of incentives and opportunities to help. Based on the Model of Frame Selection, the article develops an integrative explanation that allows resolution of this debate and that identifies constellations of causal factors conducive to helping. To empirically test this explanation, the empirical analyses use data that were collected retrospectively in the 1980s by the Altruistic Personality and Prosocial Behavior Institute (Oliner and Oliner 1988, The altruistic personality: Rescuers of Jews in Nazi Europe, 1988). Statistically, I employ Boolean probit models, a statistical method hardly known in sociology which allows reconstruction of complex patterns of causal interaction. The analyses corroborate the developed explanation. Acts of help could result either spontaneously, in reaction to being asked for help and based on strong pro-social orientations, or deliberatingly, depending on the constellation of incentives and opportunities.     

The FARSEEING real-world fall repository: a large-scale collaborative database to collect and share sensor signals from real-world falls

Background

Real-world fall events objectively measured by body-worn sensors can improve the understanding of fall events in older people. However, these events are rare and hence challenging to capture. Therefore, the FARSEEING (FAll Repository for the design of Smart and sElf-adaptive Environments prolonging Independent livinG) consortium and associated partners started to build up a meta-database of real-world falls.

Results

Between January 2012 and December 2015 more than 300 real-world fall events have been recorded. This is currently the largest collection of real-world fall data recorded with inertial sensors. A signal processing and fall verification procedure has been developed and applied to the data. Since the end of 2015, 208 verified real-world fall events are available for analyses. The fall events have been recorded within several studies, with different methods, and in different populations. All sensor signals include at least accelerometer measurements and 58 % additionally include gyroscope and magnetometer measurements. The collection of data is ongoing and open to further partners contributing with fall signals. The FARSEEING consortium also aims to share the collected real-world falls data with other researchers on request.

Conclusions

The FARSEEING meta-database will help to improve the understanding of falls and enable new approaches in fall risk assessment, fall prevention, and fall detection in both aging and disease.

     

The translocal villagers. Mining,mobility and stratification in post-apartheid South Africa

Internal labour migration from rural areas to urban centres has been and remains one of the dominant patterns of migration in South Africa. Based on data from ethnographic field research, this paper explores the mobility patterns and translocal relations of miners in the Northern Cape province of South Africa. By considering the tension between mobility and locality in a historical and political perspective, the concept of translocality helps to explain why miners try to expand their action space and, at the same time, why they are embedded in certain places. Thus, a translocal perspective enhances the interpretation of the spatio-temporal transformations in South Africa’s mining communities and beyond, as it sheds light on the agency of mine workers, superseding merely structuralist explanations.     

Assessing physical activity in inpatient rehabilitation—sensor-based validation of the PAIR

Increased physical activity is positively associated with better health in community-dwelling older persons. It is unclear whether physical activity also influences success of inpatient rehabilitation. For the assessment of physical activity in inpatient rehabilitation the Physical Activity in Inpatient Rehabilitation Assessment (PAIR), a short questionnaire based on five questions, was developed and preliminary validated. In this study, the PAIR was validated against a sensor-based physical activity measurement. Seventy functionally impaired and cognitively mostly intact patients of a German geriatric inpatient rehabilitation clinic who had undergone hip surgery (n?=?62 women, median age?=?83 years) participated. Physical activity was measured using the PAIR and a sensor-based activity monitor (Physilog ®; BioAGM, CH). Assessments were conducted at admission (T1) and 2 weeks later (T2) during the rehabilitation process. To assess concurrent and predictive validity, Spearman correlations and linear regression models were calculated using sensor-based walking activity and uptime activity (walking and standing time) as dependent variables. Criterion-related concurrent validity using physical activity sensors was weak to moderate. Correlations were slightly higher at T2 (r?=?0.45-0.53) than at T1 (r?=?0.44-0.46). The objectively measured variance of physical activity, explained by the PAIR, ranged from 25 to 43 %. PAIR activity scores and sensor-based walking or total activity increased in a dose-dependent manner, confirming the scoring system of the PAIR. The application time was usually less than 2 min. The validity of the PAIR is weak to moderate when compared to a sensor-based activity monitor and comparable to existing physical activity assessments for community-dwelling older adults.     

Impacts of the Triple Global Crisis on Growth and Poverty: The Case of Yemen

Yemen is an oil‐exporting and food‐importing country with the highest levels of poverty in the Middle East and North Africa. The impacts of the triple crisis are likely to further complicate pre‐existing conditions of conflict, oil depletion and governance failure. Using a dynamic CGE model, this article finds that oil‐driven growth in 2008 dominated the negative growth impacts of the food crisis, but that growth was not pro‐poor. The financial crisis of 2009 slowed growth sharply and raised the poverty rate to 42.8%, up from 34.8% in 2005/6. Poverty continues to be higher in rural areas, where almost half the population live in poverty.