Modeling material stress using integrated Gaussian Markov random fields

The equations of a physical constitutive model for material stress within tantalum grains were solved numerically using a tetrahedrally meshed volume. The resulting output included a scalar vonMises stress for each of the more than 94,000 tetrahedra within the finite element discretization. In this paper, we define an intricate statistical model for the spatial field of vonMises stress which uses the given grain geometry in a fundamental way. Our model relates the three-dimensional field to integrals of latent stochastic processes defined on the vertices of the one- and two-dimensional grain boundaries. An intuitive neighborhood structure of the said boundary nodes suggested the use of a latent Gaussian Markov random field (GMRF). However, despite the potential for computational gains afforded by GMRFs, the integral nature of our model and the sheer number of data points pose substantial challenges for a full Bayesian analysis. To overcome these problems and encourage efficient exploration of the posterior distribution, a number of techniques are now combined: parallel computing, sparse matrix methods, and a modification of a block update strategy within the sampling routine. In addition, we use an auxiliary variables approach to accommodate the presence of outliers in the data.     

Prior Placements of Youth Admitted to Therapeutic Foster Care and Residential Treatment Centers: The Odyssey Project Population

Two samples of youth in the child welfare system were compared—youth entering residential treatment centers (RTCs) and youth entering therapeutic foster care (TFC). Three questions were addressed: (1) Where were youth living prior to the current placement? (2) Had youth been treated in other systems of care? (3) How many prior placements did youth have? Time 1 data of the national “Odyssey Project” developed by the Child Welfare League of America were used. The^.measure utilized was the child and family characteristics form (CFC). Results revealed that youth admitted to RTCs were more likely to be entering from other systems of care and stepping down to the RTC while youth entering TFCs were more likely to be entering from within the child welfare system and stepping up to a higher level of care. The results have implications for improving clinical practice and for the development of a cross-system perspective on serving troubled youth.     

The instatement of order: state initiatives and hegemony in the modernization of French forest policy

Theories of France’s political integration, from Tocqueville to the present day, frequently disregard the political achievements of the nineteenth century state and assert that the infrastructures needed for effective governance were created during the absolutist period. Using the case of forest policy, one of the major policy domains for local and national regimes during the absolutist and nineteenth century periods, this study argues against prior accounts. It shows how the nineteenth century state, led by an elite faction of the bourgeoisie, gained infrastructural power by promoting its preferred policies as the only means of avoiding disorder and chaos. These policies advanced private property as the natural (hegemonic) form of land control. It was this project, rather than the earlier absolutist regime, that led to effective state authority over France’s territory and the achievement of the nation’s political integration. This study of forest policy provides an opportunity to evaluate state efforts to regulate economic and political life, as well as the resistance to these efforts that arose.     

Homelessness and the High Performance Cycle: A New Lens for Studying Exit Strategies

ABSTRACT

Although social work scholarship has recognized the presence and utility of goals and goal setting among the homeless, the literature remains underdeveloped. This study evaluates the extent to which the work motivation literature, mostly applied in formal business settings, can improve current understandings of how persons successfully escape homelessness. Specifically, this study focuses on the high performance cycle, a model in organizational behavior research that outlines the specific processes involved in setting and achieving goals and that provides a robust framework for analyzing goal setting among homeless persons. The article compares those who have successfully exited homelessness to those who remain chronically homeless using 40 in-depth, semistructured interviews with homeless center clients in a multicity area in the Intermountain West. Interviews addressed the employment and housing histories of research participants, their views about living unhoused, and their attempts to exit homelessness. The participants' narratives matched themes described in goal-setting research, which suggests the utility of adopting processes outlined by the high performance cycle when assisting clients in exiting homelessness. Social service professionals can benefit by incorporating the goal-setting scholarship in their work with homeless populations. Future research might use quantitative surveys and experiments to determine the generalizability of this exploratory analysis.     

Life Shocks and Homelessness

We exploited an exogenous health shock—namely, the birth of a child with a severe health condition—to investigate the effect of a life shock on homelessness in large cities in the United States as well as the interactive effects of the shock with housing market characteristics. We considered a traditional measure of homelessness, two measures of housing instability thought to be precursors to homelessness, and a combined measure that approximates the broadened conceptualization of homelessness under the 2009 Homeless Emergency Assistance and Rapid Transition to Housing Act (2010). We found that the shock substantially increases the likelihood of family homelessness, particularly in cities with high housing costs. The findings are consistent with the economic theory of homelessness, which posits that homelessness results from a conjunction of adverse circumstances in which housing markets and individual characteristics collide.     

The polarizing effect of economic inequality on class identification: Evidence from 44 countries

Using cumulative logit mixed models fitted to World Values Survey data from 44 countries, we explore the impact of economic conditions – both at the individual-level and the national-level – on social class identification. Consistent with previous research, we find a positive relationship between household income and class identification in all countries that we explore, though this relationship varies substantially. Also corroborating previous research, we find that ‘low’ class identifications are more likely in poor countries than in rich ones. However, in contrast to previous research that has neglected the role of inequality, our results indicate that the effect of economic development diminishes if income inequality is considered in the same model. We further demonstrate that income inequality has an important polarizing effect on class identification. Specifically, the relationship between household income and class identity tends to be strongest in countries with a high level of income inequality.