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131.
For nearly four decades, child welfare policy and practice have focused on the achievement of legal permanence for children in foster care. Although federal child welfare policy has resulted in the movement of children from state custody to legally permanent adoptive or guardianship families, little is known about the quality and enduring nature of these placements. A significant challenge of the twenty-first century child welfare system is how to ensure the well-being of children currently living with adoptive parents or guardians. This paper discusses child welfare policy and trends related to post-permanency well-being, including the decrease in Title IV-E foster care caseloads nationwide and the simultaneous increase in Title IV-E adoptive and guardianship caseloads. We highlight the needs of a twenty-first century child welfare system, including increased federal efforts to ensure child permanence and well-being after legal adoption or guardianship has been achieved, as well as more rigorous longitudinal and interdisciplinary research focused on the post-permanency adjustment of children and their families.  相似文献   
132.
The right to the city is a concept that helps rethink spatial–social dynamics, which has recently reinvigorated the field of organization studies. Following Lefebvre and considering the failure of both the market and the state, other scholars pinpoint the need to rethink social–spatial and geographical–historical relations. They do so by theorizing the city as a host for urban commons. Collective and non-commodified, these spatial–social experiences need to be constantly reproduced and preserved through commoning practices in the struggle against spatial injustice. A case study shows that a civil society organization (CSO) uses participatory art to (re)produce urban commons at the level of a local community and to redress partially spatial injustice. We theorize participatory art-making as a social practice of commoning, i.e., a process of organizing for the commons—collective art-based activities to serve a community—and of the common—to (re)produce a community while performing them. Such commoning practices are not only about sharing urban resources but also about using and experiencing differently urban spaces. By making participatory artworks in public spaces and co-designing street furniture with residents of poor areas, TDA helps to better cope with the tensions between residents and local authorities and between amateurs and professional artists. By negotiating the long-term implementation of these creative artworks in the public space with public authorities, TDA has fostered the empowerment of inhabitants as they have experienced citizens’ reappropriation of some public spaces in Marseille.  相似文献   
133.
Gender equality (GE) is something ‘we cannot not want’. Indeed, the pursuit of equal rights, responsibilities and opportunities for all women and men throughout a society freed from gendered oppression is widely visible in recent organizational GE initiatives. In practice, however, GE initiatives often fail in challenging gendered norms and at effecting deep‐seated change. In fact, GE measures tend to encounter resistance, with a gap between saying and doing. Using a GE project at a Swedish university, we examined the changing nature of reactions to GE objectives seeking to understand why gender inequality persists in academia. We used ‘resistance’ to identify multiple, complex reactions to the project, focusing on the discursive practices of GE. Focusing our contextual analysis on change and changes in reactions enabled a process‐oriented analysis that revealed gaps where change is possible. Thus, we argue that studying change makes it possible to identify points in time where gendered discriminatory norms are more likely to occur. However, analysing discursive practices does not itself lead to change nor to action. Rather, demands for change must start with answering, in a collaborative way, what problem we are trying to solve when we start a new GE project, in order to be relevant to the specific context. Otherwise, GE risks being the captive of consensus politics and gender inequality will persist.  相似文献   
134.
We introduce and study optimization problems which are related to the well-known Subset Sum problem. In each new problem, a node-weighted digraph is given and one has to select a subset of vertices whose total weight does not exceed a given budget. Some additional constraints called digraph constraints and maximality need to be satisfied. The digraph constraint imposes that a node must belong to the solution if at least one of its predecessors is in the solution. An alternative of this constraint says that a node must belong to the solution if all its predecessors are in the solution. The maximality constraint ensures that no superset of a feasible solution is also feasible. The combination of these constraints provides four problems. We study their complexity and present some approximation results according to the type of input digraph, such as directed acyclic graphs and oriented trees.  相似文献   
135.
In this paper we consider the multidimensional binary vector assignment problem. An input of this problem is defined by m disjoint multisets \(V^1, V^2, \ldots , V^m\), each composed of n binary vectors of size p. An output is a set of n disjoint m-tuples of vectors, where each m-tuple is obtained by picking one vector from each multiset \(V^i\). To each m-tuple we associate a p dimensional vector by applying the bit-wise AND operation on the m vectors of the tuple. The objective is to minimize the total number of zeros in these n vectors. We denote this problem by Open image in new window , and the restriction of this problem where every vector has at most c zeros by Open image in new window . Open image in new window was only known to be Open image in new window -hard, even for Open image in new window . We show that, assuming the unique games conjecture, it is Open image in new window -hard to Open image in new window -approximate Open image in new window for any fixed Open image in new window and Open image in new window . This result is tight as any solution is a Open image in new window -approximation. We also prove without assuming UGC that Open image in new window is Open image in new window -hard even for Open image in new window . Finally, we show that Open image in new window is polynomial-time solvable for fixed Open image in new window (which cannot be extended to Open image in new window ).  相似文献   
136.
In this work, we propose an optimization approach for constructing various classes of circulant combinatorial designs that can be defined in terms of autocorrelation. The problem is formulated as a so-called feasibility problem having three sets, to which the Douglas–Rachford projection algorithm is applied. The approach is illustrated on three different classes of circulant combinatorial designs: circulant weighing matrices, D-optimal matrices of circulant type, and Hadamard matrices with two circulant cores. Furthermore, we explicitly construct two new circulant weighing matrices, a CW(126, 64) and a CW(198, 100), whose existence was previously marked as unresolved in the most recent version of Strassler’s table.  相似文献   
137.
Codes of good practices provide a soft alternative to the hard legislation approach to corporate governance. These codes include a set of recommendations that companies are expected to follow in order to enhance governance structures and practices. Some of these recommendations specifically aim to improve the effectiveness of the audit committee. We investigate the relationship between the level of compliance with recommendations on the audit committee of the Spanish Unified Code and financial reporting quality, as measured by discretionary accruals and by the opinion of the audit report. We use a sample of companies listed in the Spanish stock market for the years between 2007 and 2013. Results show a strong and positive relationship between the level of compliance with recommendations and the quality of financial reporting. We also report significant results for some specific recommendations. These results are robust to various checks. Therefore, the level of compliance with recommendations on the audit committee might provide a feasible and reliable indicator of the quality of financial reports released by the company.  相似文献   
138.
In this paper we study the m-clique free interval subgraphs. We investigate the facial structure of the polytope defined as the convex hull of the incidence vectors associated with these subgraphs. We also present some facet-defining inequalities to strengthen the associated linear relaxation. As an application, the generalized open-shop problem with disjunctive constraints (GOSDC) is considered. Indeed, by a projection on a set of variables, the m-clique free interval subgraphs represent the solution of an integer linear program solving the GOSDC presented in this paper. Moreover, we propose exact and heuristic separation algorithms, which are exploited into a Branch-and-cut algorithm for solving the GOSDC. Finally, we present and discuss some computational results.  相似文献   
139.
The aim of this paper is to obtain new sharp inequalities for a large family of topological indices, including the second variable Zagreb index \(M_2^{\alpha }\), and to characterize the set of extremal graphs with respect to them. Our main results provide lower bounds on this family of topological indices involving just the minimum and the maximum degree of the graph. These inequalities are new even for the Randi?, the second Zagreb and the modified Zagreb indices.  相似文献   
140.
This research contributes to an understanding of the relationship between climate change, economic impacts and migration. We model the long-term relationship (up to 45 years of projection) between demographic dynamics—particularly migration—driven by changes in the performance of the economy due to climate changes in the Northeast region of Brazil. The region is of particular relevance to the study of climate change impacts given its large human population (28% of Brazil’s population) and high levels of impoverishment, having an extensive semi-dry area which will be severely impacted by growing temperatures. Ultimately, the integrated model generates state- and municipal-level migration scenarios based on climate change impacts on the primary economic sectors and their articulations with other sectors. Results suggest that the predicted climate changes will impact severely the agriculture sector in the region, acting as a potential migration push factor to other regions in the country. Finally, we discuss how the increased vulnerability of some groups, particularly migrants, can be factored into Brazilian public policy and planning.  相似文献   
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