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271.
One of the standard variable selection procedures in multiple linear regression is to use a penalisation technique in least‐squares (LS) analysis. In this setting, many different types of penalties have been introduced to achieve variable selection. It is well known that LS analysis is sensitive to outliers, and consequently outliers can present serious problems for the classical variable selection procedures. Since rank‐based procedures have desirable robustness properties compared to LS procedures, we propose a rank‐based adaptive lasso‐type penalised regression estimator and a corresponding variable selection procedure for linear regression models. The proposed estimator and variable selection procedure are robust against outliers in both response and predictor space. Furthermore, since rank regression can yield unstable estimators in the presence of multicollinearity, in order to provide inference that is robust against multicollinearity, we adjust the penalty term in the adaptive lasso function by incorporating the standard errors of the rank estimator. The theoretical properties of the proposed procedures are established and their performances are investigated by means of simulations. Finally, the estimator and variable selection procedure are applied to the Plasma Beta‐Carotene Level data set. 相似文献
272.
Janet Boddy June Statham Inge Danielsen Esther Geurts Hélène Join‐Lambert Sévèrine Euillet 《Children & Society》2014,28(2):152-161
In England, placement within the looked after system is not viewed as a desirable long‐term solution for most children, and policy has prioritised continued contact with parents, and swift return home, wherever possible. This review examines policy approaches to work with families of looked after children in England and in three other European countries: Denmark, France and the Netherlands, aiming to identify areas for shared learning in relation to this challenging area of policy and practice. The research highlights relationships between care populations and policy understandings of the purpose of work with families, including understandings of children's and/or parents’ rights. 相似文献
273.
Starting in the 2000s, Denmark and Norway have undergone extensive restructuring of their health-related social benefit programmes, including how they are governed. Several reforms have sought to enhance inter-sectoral collaboration. Aiming at ensuring patients’ faster return to work, policy-makers have instituted economic incentives to both individuals and the health and welfare organisations who handle them. Through an institutional logics approach, this paper explores how hospital social workers in these countries are experiencing these changes. The ‘social’ part of post-treatment care and rehabilitation receives more attention in the Norwegian institutional set-up than in the Danish, and whilst challenges are experienced in both countries, in group interviews Danish social workers in particular express concerns about the implications of the accelerated return-to-work focus. In both countries, they report increasing difficulties in ‘making their way through’ the state-municipal bureaucracy. However, by drawing on the formal health knowledge derived from medical settings and the symbolic capital it bestows on them, they often manage to negotiate the work-and-welfare services, thereby transforming the social context for the patients. 相似文献
274.
Sondra S. Teske Mark H. Weir Timothy A. Bartrand Yin Huang Sushil B. Tamrakar Charles N. Haas 《Risk analysis》2014,34(5):911-928
The effect of bioaerosol size was incorporated into predictive dose‐response models for the effects of inhaled aerosols of Francisella tularensis (the causative agent of tularemia) on rhesus monkeys and guinea pigs with bioaerosol diameters ranging between 1.0 and 24 μm. Aerosol‐size‐dependent models were formulated as modification of the exponential and β‐Poisson dose‐response models and model parameters were estimated using maximum likelihood methods and multiple data sets of quantal dose‐response data for which aerosol sizes of inhaled doses were known. Analysis of F. tularensis dose‐response data was best fit by an exponential dose‐response model with a power function including the particle diameter size substituting for the rate parameter k scaling the applied dose. There were differences in the pathogen's aerosol‐size‐dependence equation and models that better represent the observed dose‐response results than the estimate derived from applying the model developed by the International Commission on Radiological Protection (ICRP, 1994) that relies on differential regional lung deposition for human particle exposure. 相似文献
275.
Stephanie G. Schartel Dunn Gwendelyn S. Nisbett 《Atlantic journal of communication》2017,25(3):197-206
Fandom and psychological reactance theory, a framework for understanding reactions to messages perceived to limit an individual’s freedom to choose freely, are used to examine the influence of sports celebrities. An experiment was conducted (n = 283) to examine the impact of source similarity and controlling language use on reactance levels and message evaluations. Findings suggest that sources perceived to be similar generated less reactance than dissimilar sources. Similar source messages were also linked to greater potential for information-seeking behavior. High- versus low-controlling language use was examined in conjunction with similarity; low-controlling language was found to generate the least reactance regardless of source similarity. Implications for the use of celebrity advocacy in marketing and public relations are discussed. 相似文献
276.
277.
Statistical process monitoring (SPM) is a very efficient tool to maintain and to improve the quality of a product. In many industrial processes, end product has two or more attribute-type quality characteristics. Some of them are independent, but the observations are Markovian dependent. It is essential to develop a control chart for such situations. In this article, we develop an Independent Attributes Control Chart for Markov Dependent Processes based on error probabilities criterion under the assumption of one-step Markov dependency. Implementation of the chart is similar to that of Shewhart-type chart. Performance of the chart has been studied using probability of detecting shift criterion. A procedure to identify the attribute(s) responsible for out-of-control status of the process is given. 相似文献
278.
Sharon S. Oselin 《Sociological Forum》2016,31(1):203-222
Violence among inner‐city men is a pressing social concern, and the central focus of much academic research. Many frame it as a phenomenon that certain men perpetuate—those who inhabit disadvantaged, impoverished communities—and argue it is linked to performances of “street” masculinity. In this article, I examine male street‐based sex workers’ willingness to become embroiled in violent exchanges. In a departure from theoretical predictions, my findings reveal these men expend considerable effort to remain nonviolent with others immersed in the sex trade, a decision based upon their desire for the acquisition of capital as well as their calculation of risks. In doing so, they construct and perform a nuanced version of masculinity, which I call pacifist masculinity. Few studies analyze peaceful and conciliatory interactions among men in these contexts, an absence that only serves to reify assumptions about rampant hostility and aggression. I draw on interviews with 19 men involved in street prostitution in Chicago in 2012. This article contributes to a clearer understanding of male–male violence in high‐risk environments, examines the prominent factors that inform decisions to assault others, and explores how such actions challenge hegemonic masculinity. 相似文献
279.
Outlier detection algorithms are intimately connected with robust statistics that down‐weight some observations to zero. We define a number of outlier detection algorithms related to the Huber‐skip and least trimmed squares estimators, including the one‐step Huber‐skip estimator and the forward search. Next, we review a recently developed asymptotic theory of these. Finally, we analyse the gauge, the fraction of wrongly detected outliers, for a number of outlier detection algorithms and establish an asymptotic normal and a Poisson theory for the gauge. 相似文献
280.
Application of a QMRA Framework to Inform Selection of Drinking Water Interventions in the Developing Context
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S. R. Petterson 《Risk analysis》2016,36(2):203-214
The aim of this study was to develop a modified quantitative microbial risk assessment (QMRA) framework that could be applied as a decision support tool to choose between alternative drinking water interventions in the developing context. The impact of different household water treatment (HWT) interventions on the overall incidence of diarrheal disease and disability adjusted life years (DALYs) was estimated, without relying on source water pathogen concentration as the starting point for the analysis. A framework was developed and a software tool constructed and then implemented for an illustrative case study for Nepal based on published scientific data. Coagulation combined with free chlorine disinfection provided the greatest estimated health gains in the short term; however, when long‐term compliance was incorporated into the calculations, the preferred intervention was porous ceramic filtration. The model demonstrates how the QMRA framework can be used to integrate evidence from different studies to inform management decisions, and in particular to prioritize the next best intervention with respect to estimated reduction in diarrheal incidence. This study only considered HWT interventions; it is recognized that a systematic consideration of sanitation, recreation, and drinking water pathways is important for effective management of waterborne transmission of pathogens, and the approach could be expanded to consider the broader water‐related context. 相似文献