The main objective of this work is to evaluate the performance of confidence intervals, built using the deviance statistic, for the hyperparameters of state space models. The first procedure is a marginal approximation to confidence regions, based on the likelihood test, and the second one is based on the signed root deviance profile. Those methods are computationally efficient and are not affected by problems such as intervals with limits outside the parameter space, which can be the case when the focus is on the variances of the errors. The procedures are compared to the usual approaches existing in the literature, which includes the method based on the asymptotic distribution of the maximum likelihood estimator, as well as bootstrap confidence intervals. The comparison is performed via a Monte Carlo study, in order to establish empirically the advantages and disadvantages of each method. The results show that the methods based on the deviance statistic possess a better coverage rate than the asymptotic and bootstrap procedures. 相似文献
In this article, we consider the prediction of future failure times based on Type-I hybrid censored samples. Point predictors and prediction intervals using different procedures are discussed for a general model. The exponential and Rayleigh distributions are used as illustrative examples to show the most simplified forms of the so obtained predictors as well as prediction intervals. Intensive simulation study and a real life dataset are presented to illustrate our findings and results. 相似文献
This article explores collective efforts by undocumented youth activists to use storytelling to reframe the debates around immigration reform and discursively position themselves as the rightful leaders of a movement that had been dominated by adult citizen‐advocates. Drawing on 19 months of fieldwork, 37 in‐depth interviews, and hundreds of pages of movement documents, I show how youth activists in the United States worked together to develop stories that: (1) drew into question the legitimacy of adult citizen‐advocates to speak on issues of immigration and (2) cast undocumented immigrant youth as the proper authorities on these matters. I argue that through collective storytelling and character work, the activists were able to subvert adult citizen authority and construct themselves as powerful, new collective actors in the contemporary immigrant rights movement. I conclude by discussing some of the practical implications and limitations of using narrative reframing strategies to advance the social change agendas of marginalized movement factions. 相似文献
Focus group methods were used to explore heterosexual women’s receptive anal sex attitudes and motivations. Behaviors under investigation included penile–anal intercourse (PAI), manual–anal stimulation, oral–anal contact, and the use of sex toys. A total of 33 self-identified heterosexual women ages 18 to 30 recruited from two metropolitan areas in the Midwestern United States participated in one of six focus groups. The findings suggest that women viewed heterosexual anal sex as an emerging norm. Attitudes and motivations were complex and varied by behavior. Dominant themes included curiosity, pain, pleasure, and stigma. Relational factors, including acquiescence, coercion, and consent, were also salient among participants. Factors that influence anal sexual behaviors may not be entirely distinct from those that influence other sexual behaviors; however, factors that influence anal intercourse may be distinct from those that influence nonintercourse anal sex. Improved understanding will allow scientists to better understand the integration of anal sex behaviors into the broader sexual repertoire. 相似文献
Studies have generally supported telehealth as a feasible, effective, and safe alternative to in‐office visits. Telehealth may also be of particular benefit to couples/families interested in relational treatments, as it addresses some of the barriers that may be more prominent for families, such as childcare and scheduling difficulties. Therapists interested in expanding their practice to include telehealth should understand ethical and practical considerations of this modality. This article discusses areas unique to the delivery of telehealth to couples and families. Each broad domain is then elaborated upon with case examples from actual clinical practice and specific recommendations for addressing potential difficulties. Authors recommend further empirical research examining differences in modality outcome, as well as feasibility of the suggestions proposed here. 相似文献
Objective: The objective of this study was to understand substance use patterns of alcohol, marijuana, and simultaneous alcohol and marijuana (SAM) use among 2- and 4-year college students. Participants: Participants were 526 young adults aged 18–23 (n?=?355 4-year students; n?=?171 2-year students) recruited from February 2015 to January 2016 who were participating in a larger longitudinal study. Methods: Latent class analysis (LCA) was used to identify past-month classes of alcohol, marijuana, and SAM use. Results: Among both 2- and 4-year students, a four-class solution yielded the best-fitting model, with 2-year classes tending to include greater marijuana use and less alcohol use and 4-year classes tending to include heavy alcohol use. Demographic characteristics were largely similar across classes. Conclusions: Classes of alcohol, marijuana, and SAM use differed by education status. Screening and prevention efforts for 4-year students may need to be tailored for the needs of 2-year students. 相似文献
Although we know that high‐quality employee–organization relationships are beneficial, these relationships are complex and not fully understood, especially among employees of nonprofit organizations. In particular, we know little about how these employees perceive trust, which may overlook an important contributor to effective management. We begin to address this issue by testing a new theoretical model that conceptualizes perceived insider status, psychological ownership, and organizational identification as foundations for the perception of justice and subsequent trust. Our results indicate that psychological ownership and perceived insider status relate to trust through procedural and interpersonal justice. These results contrast those typically found in for‐profit contexts in that organizational identification did not predict justice and that distributive and informational justice did not predict trust. 相似文献
Urban Ecosystems - Urban streams provide important ecosystem services to cities’ population, from the maintenance of urban biodiversity, temperature, humidity and air quality to improving... 相似文献
High population growth in the tropics is driving urbanisation, removing diverse natural ecosystems. This is causing native species to suffer while introduced synanthropes flourish. City planners are developing urban greenspace networks, in part trying to address this issue. Architects contribute to these greenspace networks by designing elevated and ground level green spaces on large-scale buildings. However, little evidence is available on whether building green spaces support native fauna. This is true for birds in tropical Singapore that support important ecosystem services and have existence value. Therefore, in this study, we conducted bird surveys and statistical analyses to determine, if and how vegetation on three building green space types (ground gardens, roof gardens and green walls) have a positive impact on native or introduced bird species. We found that elevated greenery (roof gardens and green walls) on large-scale buildings supported a higher richness of birds and abundance of urban native birds than control roofs and walls without vegetation. Ground gardens supported similar levels of native species as roof gardens but also a larger proportion of generalist synanthropes. However, we found no tropical forest habitat specialists across any space type. Therefore, we recommend roof gardens and ground gardens as a potential space for urban natives outside of a less competitive ground-level urban environment. Our study also found certain building design elements (height of elevated space, presence of specific plants) supported different species groups. Therefore, we suggest that these ecological requirements for different species groups are considered when designing a building’s green space.