Probabilistic integration of a continuous dynamical system is a way of systematically introducing discretisation error, at scales no larger than errors introduced by standard numerical discretisation, in order to enable thorough exploration of possible responses of the system to inputs. It is thus a potentially useful approach in a number of applications such as forward uncertainty quantification, inverse problems, and data assimilation. We extend the convergence analysis of probabilistic integrators for deterministic ordinary differential equations, as proposed by Conrad et al. (Stat Comput 27(4):1065–1082, 2017. https://doi.org/10.1007/s11222-016-9671-0), to establish mean-square convergence in the uniform norm on discrete- or continuous-time solutions under relaxed regularity assumptions on the driving vector fields and their induced flows. Specifically, we show that randomised high-order integrators for globally Lipschitz flows and randomised Euler integrators for dissipative vector fields with polynomially bounded local Lipschitz constants all have the same mean-square convergence rate as their deterministic counterparts, provided that the variance of the integration noise is not of higher order than the corresponding deterministic integrator. These and similar results are proven for probabilistic integrators where the random perturbations may be state-dependent, non-Gaussian, or non-centred random variables.
The tragic killing of George Floyd at the hands of the police resulted in hundreds of thousands of protestors marching in the streets demanding change. The call for change criticized the killing of Blacks by law enforcement and challenged White supremacy as an institution of social control and racial violence. A key component of the marches and protests was a message to the residents of the United States: “Black Lives Matter.” As society grapples with a reckoning, researchers studying police violence for the past 6 decades have been empirically and theoretically debating the reasons why use of force by law enforcement continues to have a higher proportion of Black and Brown victims compared to Whites. Although the research on fatal police killings was studied by only a small number of individuals prior to 2014, after the killing of Michael Brown in Ferguson, Missouri the research in different areas of the country increased rapidly as did the forms of analysis and research disciplines making their own contributions. The Washington Post and Guardian news agencies established that deaths at the hands of the police were occurring for at least 900 to 1100 individual deaths per year for which firearms resulted in the greatest cause of death. As US government agencies failed to produce a national data source on police involved killings, the media took a leading role in providing greater national understanding. The authors examine what role academic researchers contribute to the discussion for solutions, particularly those from marginalized backgrounds. As protestors march, lawyers sue and defend, and politicians create new forms of legislation, researchers need to play a more important role initiating critical studies, making sense of the data, and providing a theoretical framework for which police violence can be understood. This article will provide an overview of the literature on racialized police violence, point out key patterns involving racial and ethnic disparities, and emphasize how researchers can play a more important role in advocating for change. 相似文献
In this paper, I examine the time men spent on childcare during the recession of 2007–2009. The recession provides a sudden change in the employment opportunities of men relative to women in the United States. Using the American Time Use Survey and the linked Current Population Survey, I show that this lopsided shock to employment opportunities was accompanied by an increase in the average amount of time men spent on childcare. In particular, men’s average time on physical care for children increased during the recession; this is an element of childcare that men perform less than women. I decompose the total change in average time on childcare into behavioral, compositional, and between group change. A behavioral change among employed men accounted for the majority of the total increase in the average time spent on childcare; among men who are out of the labor force, the increase is entirely due to compositional changes. 相似文献
Novel approaches to natural resource management, particularly those which promote stakeholder participation, have been put forward as fundamental ingredients for establishing resilient, polycentric forms of environmental governance. This is nowhere more pertinent than in the case of the complex adaptive systems associated with urban areas. Decentralisation of urban green space management has been posited as an element thereof which, according to resilience thinking, should contribute to the adaptive capacity of cities and the ecosystem services upon which they rely. Implicit in this move towards increased adaptive capacity is the ability to manage through innovation. Although the importance of innovation towards system adaptability has been acknowledged, little work has thus far been carried out which demonstrates that innovative use of urban green space represents a form of adaptive response to environmental conditions. The current paper reports on research which maps examples of organised social-ecological innovation (OSEI) in an urban study area and evaluates them as adaptive responses to local environmental conditions which may contribute to system resilience. The results present OSEI as a coherent body of responses to local social and environmental deprivation, exhibiting diversity and adaptability according to individual contexts. The study therefore provides evidence for the importance of local stakeholder-led innovation as in the building of adaptive capacity in urban social-ecological systems. 相似文献
Objectives: Attachment insecurity may be more pronounced among young gay and bisexual men (YGBM). Further, attachment insecurity is associated with dysregulated patterns of emotion regulation, which can lead to depression. However, pathways linking attachment insecurity to depression are underexplored among YGBM. Methods: This study used pilot data from N?=?67 YGBM to examine if emotion dysregulation mediated the association between attachment insecurity and depression. Results: Results supported the study hypotheses. Attachment insecurity was associated with emotion dysregulation, which was associated with depression. Conclusion: Findings provide preliminary evidence that emotion regulation training may be a useful approach for addressing depression among YGBM. 相似文献
PCORnet, the National Patient-Centered Clinical Research Network, seeks to establish a robust national health data network for patient-centered comparative effectiveness research. This article reports the results of a PCORnet survey designed to identify the ethics and regulatory challenges anticipated in network implementation. A 12-item online survey was developed by leadership of the PCORnet Ethics and Regulatory Task Force; responses were collected from the 29 PCORnet networks. The most pressing ethics issues identified related to informed consent, patient engagement, privacy and confidentiality, and data sharing. High priority regulatory issues included IRB coordination, privacy and confidentiality, informed consent, and data sharing. Over 150 IRBs and five different approaches to managing multisite IRB review were identified within PCORnet. Further empirical and scholarly work, as well as practical and policy guidance, is essential if important initiatives that rely on comparative effectiveness research are to move forward. 相似文献
The routing and wavelength assignment problem (RWA) has shown to be NP-hard if the wavelength continuity constraint and the objective of minimizing the number of wavelengths are considered. This paper introduces a multi-neighborhood based iterated tabu search algorithm (MN-ITS), which consists of three neighborhoods with a unified incremental evaluation method, to solve the min-RWA problem. The proposed MN-ITS algorithm is tested on a set of widely studied real world instances as well as a set of challenging random ones in the literature. Comparison with other reference algorithms shows that the MN-ITS algorithm is able to improve five best upper bounds obtained by other competitive reference algorithms in the literature. This paper also presents an analysis to show the significance of the unified incremental evaluation technique and the combination of multiple neighborhoods. 相似文献
This paper studies how rising male incarceration and its impact on marriage markets has affected female incentives to gain weight. Exogenous variation in marriage market conditions is obtained from differential trends in male incarceration rates across markets defined by race, location and age. We provide evidence that marriage market conditions do in fact affect the incidence of obesity. In particular, we find that increases in male imprisonment that reduced the male–female sex-ratio explain about 18 % of the increase in the female obesity rate for African-Americans in the United States over the 1990s. Results are particularly large for those in the younger age group (ages 18–23). 相似文献
Sweden is a welfare state with a family policy that strongly emphasizes equality without distinction by place of birth or gender. In this study, we investigate the differences in uptake of parental leave between native and immigrant mothers, and the connection to labour-market attachment. Sweden represents a unique case study, not only because of the strong effort to combine work and family for all women and men, the high level of fertility and the large presence of immigrants in the country; it also enables a detailed and sophisticated analysis based on the high-quality data derived from its population registers. We find that immigrant mothers use more parental leave benefit the first year after their child’s birth, but then fewer in the second year compared with native mothers. The differences diminish when labour-market activity is controlled for. Additionally, after a time in Sweden, immigrant mothers use leave more similarly to how native mothers do. 相似文献
Research on subjective wellbeing includes studies of both domain-related and global distress. The mental health literature,
though, focuses almost exclusively on global distress. This seems to be partly due to a common belief that psychological distress,
and the moods that comprise distress, necessarily lack referential content. However, if that were the case it would make little
sense for any study to ever focus on domain-related distress. The research presented in this report clarifies the relation
between global and domain-related distress. We compare confirmatory factor analytic models of the joint relationship among
symptoms of global distress with affective symptoms of distress about work, home, and physical appearance. Data are from a
general population telephone survey. In the best-fitting models domain-related distress and global psychological distress
are related but distinct latent variables. We discuss the theoretical and methodological implications of the models, and model
choice. 相似文献