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851.
We propose an adaptive functional autoregressive (AFAR) forecast model to predict electricity price curves. With time-varying operators, the AFAR model can be safely used in both stationary and nonstationary situations. A closed-form maximum likelihood (ML) estimator is derived under stationarity. The result is further extended for nonstationarity, where the time-dependent operators are adaptively estimated under local homogeneity. We provide theoretical results of the ML estimator and the adaptive estimator. Simulation study illustrates nice finite sample performance of the AFAR modeling. The AFAR model also exhibits a superior accuracy in the forecast exercise of the California electricity daily price curves compared to several alternatives. 相似文献
852.
Estimates of subgroup treatment effects in overall nonsignificant trials: To what extent should we believe in them?
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Julien Tanniou Ingeborg van der Tweel Steven Teerenstra Kit C.B. Roes 《Pharmaceutical statistics》2017,16(4):280-295
In drug development, it sometimes occurs that a new drug does not demonstrate effectiveness for the full study population but appears to be beneficial in a relevant subgroup. In case the subgroup of interest was not part of a confirmatory testing strategy, the inflation of the overall type I error is substantial and therefore such a subgroup analysis finding can only be seen as exploratory at best. To support such exploratory findings, an appropriate replication of the subgroup finding should be undertaken in a new trial. We should, however, be reasonably confident in the observed treatment effect size to be able to use this estimate in a replication trial in the subpopulation of interest. We were therefore interested in evaluating the bias of the estimate of the subgroup treatment effect, after selection based on significance for the subgroup in an overall “failed” trial. Different scenarios, involving continuous as well as dichotomous outcomes, were investigated via simulation studies. It is shown that the bias associated with subgroup findings in overall nonsignificant clinical trials is on average large and varies substantially across plausible scenarios. This renders the subgroup treatment estimate from the original trial of limited value to design the replication trial. An empirical Bayesian shrinkage method is suggested to minimize this overestimation. The proposed estimator appears to offer either a good or a conservative correction to the observed subgroup treatment effect hence provides a more reliable subgroup treatment effect estimate for adequate planning of future studies. 相似文献
853.
The paper investigates various nonparametric models including regression, conditional distribution, conditional density and conditional hazard function, when the covariates are infinite dimensional. The main contribution is to prove uniform in bandwidth asymptotic results for kernel estimators of these functional operators. Then, the application issues, involving data-driven bandwidth selection, are discussed. 相似文献
854.
C. J. Brien 《Australian & New Zealand Journal of Statistics》2017,59(4):327-352
Multiphase experiments are introduced and an overview of their design and analysis as it is currently practised is given via an account of their development since 1955 and a literature survey. Methods that are available for designing and analysing them are outlined, with an emphasis on making explicit the role of the model in their design. The availability of software and its use is described in detail. Overall, while multiphase designs have been applied in areas such as plant breeding, plant pathology, greenhouse experimentation, product storage, gene expression studies, and sensory evaluation, their deployment has been limited. 相似文献
855.
The importance of good governance is praised by many academics and practitioners. The prominence of the subject suggests that measurement is important. However, setting out to measure the quality of governance empirically is controversial. Doubts regarding the feasibility and meaningfulness of this undertaking are widespread in the literature. Recognizing the potential caveats, the current article discusses a set of guidelines for structuring a theoretically sound local governance assessment tool based on the Decision Analysis and Operational Research literatures. The authors argue that using a multi-criteria model which employs several objective (quantitative and qualitative) indicators and relies on a participatory method to aggregate them is a suitable way of developing sensible Local Governance Indicators. The purpose here is to provide a detailed roadmap for any country (or region, or locality) willing to engage in the assessment of the quality of local governance. The real-world implementation of a model developed according to these guidelines could help raise awareness, promote good practices and increase the ‘governance literacy’ of citizens. By operationalizing good governance, analysts may also be able to further investigate the relationships between local governance practices and several socio-economic factors. 相似文献
856.
The multiple non symmetric correspondence analysis (MNSCA) is a useful technique for analyzing a two-way contingency table. In more complex cases, the predictor variables are more than one. In this paper, the MNSCA, along with the decomposition of the Gray–Williams Tau index, in main effects and interaction term, is used to analyze a contingency table with two predictor categorical variables and an ordinal response variable. The Multiple-Tau index is a measure of association that contains both main effects and interaction term. The main effects represent the change in the response variables due to the change in the level/categories of the predictor variables, considering the effects of their addition, while the interaction effect represents the combined effect of predictor categorical variables on the ordinal response variable. Moreover, for ordinal scale variables, we propose a further decomposition in order to check the existence of power components by using Emerson's orthogonal polynomials. 相似文献
857.
Ernest Gonzales Lisa A. Marchiondo Jing Tan Yi Wang Huajuan Chen 《Journal of gerontological social work》2017,60(3):245-254
ABSTRACTThe Aging Semantic Differential (ASD) is the most widely used instrument to measure young people’s attitudes towards older adults. This study translated the ASD to Mandarin and examined its psychometric properties. The Mandarin-ASD contains three latent factors (Personality and Mental Health, Societal Participation, and Physical) that have high internal reliability and reasonable discriminate validity. Social work researchers, practitioners and allied professionals may utilize the ASD-Mandarin instrument to measure young people’s attitudes towards older adults in China. We issue a call for a universal-ASD that can be applied across different cultural contexts. 相似文献
858.
‘I want to be better than you:’ lived experiences of intergenerational child maltreatment prevention among teenage mothers in and beyond foster care
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Elizabeth M. Aparicio 《Child & Family Social Work》2017,22(2):607-616
The growing body of research on teenage motherhood in foster care has largely focused on the risks involved for both mother and child, yet these mothers depict a much more complex picture of their own experience of becoming and being mothers. The current study employed interpretative phenomenological analysis to explore 18 in‐depth, qualitative interviews from six participants on the meaning and experience of motherhood among teenage mothers in foster care and in the years immediately after ageing out. This study focused on a particular dimension of motherhood: participants' efforts to break the cycle of child abuse and neglect with their own children. Two themes emerged as characteristic of these experiences: (i) treating children well/parenting differently and avoiding the system; and (ii) reducing isolation and enhancing support. Given the increased likelihood of the children of teen mothers – particularly those who have been maltreated – becoming involved with the child welfare system, study findings suggest possible strategies for disrupting cycles of intergenerational child welfare involvement generated by young mothers themselves. Practice implications for addressing possible substance abuse, mental health and relational and parenting needs are discussed. 相似文献
859.
Bo Hyun Lee Jiajia Zhu David Diaz Jeffrey Fischer Lisa Y. Flores Ching‐Lan Lin Jennah Beilgard Sarah May Melissa Munoz Mohamad Shahin Ruben Atilano 《The Career development quarterly》2017,65(4):288-301
This study extends Flores et al.'s ( 2006 ) 36‐year analysis of racial/ethnic minority (REM) career research to identify recent trends in choice of topics and leading individual and institutional contributors. The authors identified 166 articles on REM career research published from 2005 to 2015 in the Journal of Vocational Behavior, The Career Development Quarterly, the Journal of Career Assessment, and the Journal of Career Development. Of these studies, 92% were empirical, with more than three quarters of these using quantitative rather than qualitative methodology. Most frequently, the empirical studies (n = 153) were based on samples of high school (30.7%) or undergraduate (34.6%) students. The authors discuss the implications of their findings and suggest ways to expand REM career research in the future. 相似文献
860.
The present study focused on cultural constructions of disability in virtual settings, examining specifically how cultural constructions of disability were mediated through the use of online technology. This was accomplished by identifying and analyzing Greek Cypriot online news media articles and online readers’ posts in response to these articles. Findings indicated that disability in these online settings mainly reproduced traditional models of disability, with the charity model being more prevalent. However, there were instances in which dominant discourses of disability were ruptured through the introduction of counter-narratives in users’ posts which echoed the human rights model of disability. Implications for the fields of media, education and disability studies are discussed in relation to the possibility of using digital media to contribute to the challenge of critical media literacy to address issues of diversity and disability. 相似文献