The well‐known deterministic resource‐constrained project scheduling problem involves the determination of a predictive schedule (baseline schedule or pre‐schedule) of the project activities that satisfies the finish–start precedence relations and the renewable resource constraints under the objective of minimizing the project duration. This baseline schedule serves as a baseline for the execution of the project. During execution, however, the project can be subject to several types of disruptions that may disturb the baseline schedule. Management must then rely on a reactive scheduling procedure for revising or reoptimizing the baseline schedule. The objective of our research is to develop procedures for allocating resources to the activities of a given baseline schedule in order to maximize its stability in the presence of activity duration variability. We propose three integer programming–based heuristics and one constructive procedure for resource allocation. We derive lower bounds for schedule stability and report on computational results obtained on a set of benchmark problems. 相似文献
In this overview of governance mechanisms developed within open source software (OSS) circles, three types of governance are
studied: ‘spontaneous’ governance, internal governance, and governance towards outside parties. Moreover, two main ways in
which lessons from OSS can be applied elsewhere are explored: peer production of products other than software, and embedding
‘peer-produced’ products and peer processes into existing institutions (‘coupling’).
Shaped by inconsistent policy decisions, the COVID-19 pandemic in Brazil has made structural gender and racial inequalities more acute. Black and low-income women are overburdened with unpaid domestic work, increased domestic violence, and more vulnerable due to informal and exploitative working regimes. These structural aspects are intensifying, since the pandemic has broadened inequalities at the intersection of gender, race, labor market, and social class. We examine pre- and during pandemic inequalities on three dimensions: (a) unpaid domestic and care work, (b) women's labor market participation, and (c) domestic violence. We link the care diamond model and racial stratification forwarding a feminist perspective by examining how the interlocking of race and gender in Brazil renders different socioeconomic dynamics to the detriment of Black and low-income women. Based on this evidence, we stress that a more equal future requires a better social protection and policies targeting the articulation of gender, race, and class. 相似文献
According to Hobfoll’s conservation of resources theory (1989), psychological resources such as resilience and self-efficacy could mediate the effects of unemployment on well-being. The objective of this study is to analyse the mediating role of self-efficacy and resilience on the relationship between the amount of time unemployed and psychological distress. A sample of unemployed persons from the Region of Murcia was used (N = 280). With a transversal design and using the macro PROCESS for SPSS (2013), a multiple mediation model is proposed which analyses the mediating role of psychological resources in relation to the amount of time unemployed and self-perceived health. The explained variance of this model is 23.79%. The results show that only self-efficacy partially mediates in the relationship between the two variables (β = .18, SD = 0.06, p < .01). The main contribution of this article is showing that personal psychological resources are an effective tool to cope with life stressors, such as, in this case, unemployment. 相似文献
Among 70 community couples who reported childhood sexual abuse (CSA) and disclosure to their partner, this study examined associations between survivors’ perception of partner responses to their disclosure, and both partners’ sexual and relationship satisfaction. Participants completed self‐report questionnaires online. Results of path analyses within an actor–partner interdependence model indicated that survivors’ perceived partner responses of emotional support to disclosure were associated with their own and their partners’ higher sexual satisfaction. Survivors’ perceived responses of being stigmatized/treated differently by the partner were associated with their own and their partners’ poorer relationship satisfaction. Findings suggest that survivor‐perceived partner responses to the disclosure of CSA can have a positive and a negative impact on the sexual and relationship satisfaction of both partners. 相似文献
Government–nonprofit relations in China have transformed over the past three decades. Building on policy instrument theory, this article explores which policy instruments have been used to steer nonprofits at the central level and how the use of policy instruments has changed over time. This article is based on a content analysis of 300 central-level policy documents for nonprofits using NVivo. The results show that 22 kinds of policy instruments have been used to steer nonprofits. A steep upward trend is evident in the use of four categories of policy instruments for nonprofits: authority, incentive, information, and organization. Policy instruments for nonprofits have advanced in diversity, emphasizing indirect control. The central government continues to show a significant predisposition toward regulatory instruments, which have evolved from ex ante regulation to process and ex post regulation. This article contributes to the public management literature by identifying which policy instruments governments use to shape government–nonprofit relations.
We offer an account of reading comprehension that we believe will help clarify some common conceptual confusions in the relevant literature, as well as contribute to existing functional accounts. We argue that defining texts qua texts as stimulus classes, on the one hand, and equating “comprehension” with behavior (covert or otherwise), on the other, are not useful conceptual moves, especially when behavioral settings go beyond basic literacy skills acquisition. We then analyze the structure of the contingencies that usually evoke talk of “comprehension” using techniques from analytic philosophy. We show how keeping the results of this analysis in mind can help avoid the conceptual bafflement that often arises, even among behavior analysts, when defining or assessing behavioral phenomena related to reading comprehension. Using two contrasting cases (legal texts and stories), we argue that what counts as comprehension depends, not peripherally but crucially, on the shared social practices of which texts are a part. Finally, we propose a new framework for classifying reader–text contingencies by combining two dimensions: openness of setting and embeddedness of reinforcement. 相似文献
Gambling disorder (GD) is a prevalent condition for which no pharmacological treatment has yet been approved, although there is evidence that topiramate can reduce impulsivity in GD and craving in various addictive behaviors. The goal of this study was to investigate the effectiveness of topiramate combined with cognitive restructuring for GD in a two-center, randomized, double-blind clinical trial. Participants were individuals seeking outpatient treatment for GD (n = 30), treated with either topiramate or placebo combined with a brief cognitive intervention, over a 12-week period, the dose of topiramate being tapered up during the first 8 weeks. The main outcome measures were gambling craving, behavior, and cognitive distortions; impulsivity; depression and social adjustment. Topiramate proved superior to placebo in reducing gambling craving (P = 0.017); time and money spent gambling (P = 0.007 and P = 0.047, respectively); cognitive distortions related to gambling (P = 0.003); and social adjustment (P = 0.040). We found no significant effects on impulsivity or depression. These findings are in contrast with data from a previous clinical trial with topiramate for GD. In the current study, we found that topiramate affects features specifically related to gambling addiction and had no significant effect on associated phenomena such as impulsiveness and depression. We believe that this response could be due to synergistic interaction between topiramate and the cognitive intervention. 相似文献
This article contains the text and discussion of a debate held at the IUAES World Congress in Anthropology at Manchester University in 2013. The motion was proposed by Bela Feldman-Bianco (State University of Campinas), seconded by Noel Salazar (University of Leuven) and was opposed by Shahram Khosravi (Stockholm University), seconded by Nicholas de Genova (then at Goldsmiths’ College). The debate was chaired by Simone Abram (Durham University). 相似文献
Urbanization threatens biodiversity worldwide and is expected to increase in the future. This involves intensification of fragmentation and increase of urban forest remnants. Thus, it is important to understand the functioning of these patches for the preservation of local biodiversity. Mutualistic interactions such as seed dispersal have a key role in the dynamics of plant populations and could help to mitigate the negative effects of fragmentation on wild plant populations. In this context, we have used the mastic Pistacia lentiscus, a common Mediterranean shrub, as a model to study the interaction between seed dispersal by birds and the local genetic diversity of individuals in a highly fragmented semiarid forestry area of the Iberian Southeast (Murcia, Spain). Results reveal a high genetic diversity and a lack of differentiation between shrub patches of P. lentiscus in the area, probably as a result of a strong, but rather recent fragmentation, and an apparently poor contribution of birds to the dispersal of Pistacia seeds. However, the existence of latent impacts cannot be discarded, since at least one of the patches shows some signs of inbreeding. 相似文献