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1.
On Optimality of Bayesian Wavelet Estimators   总被引:2,自引:0,他引:2  
Abstract.  We investigate the asymptotic optimality of several Bayesian wavelet estimators, namely, posterior mean, posterior median and Bayes Factor, where the prior imposed on wavelet coefficients is a mixture of a mass function at zero and a Gaussian density. We show that in terms of the mean squared error, for the properly chosen hyperparameters of the prior, all the three resulting Bayesian wavelet estimators achieve optimal minimax rates within any prescribed Besov space     for p  ≥ 2. For 1 ≤  p  < 2, the Bayes Factor is still optimal for (2 s +2)/(2 s +1) ≤  p  < 2 and always outperforms the posterior mean and the posterior median that can achieve only the best possible rates for linear estimators in this case.  相似文献   
2.
Although empathy has been found to distinguish effective counsellors from less effective counsellors, human services professionals who continually experience negative emotional reactions to the feelings that clients express in counselling may be at risk of developing burnout. This study examined the hypothesis that emotional empathy rather than cognitive empathy is associated with burnout. The sample of human services professionals consisted of 71 Salvation Army Officers. Multiple regression was used to investigate whether the dimensions of empathy could predict three aspects of burnout: personal accomplishment, emotional exhaustion and depersonalization. The first regression analysis indicated that personal distress and empathic concern were significant predictor of personal accomplishment. The second analysis indicated that personal distress was a significant predictor of emotional exhaustion. The third indicated that empathic concern was a significant predictor of depersonalization. Although these results support the hypothesis, personal distress was negatively associated with personal accomplishment, whereas empathic concern was positively associated with personal accomplishment. The small size of the sample may have influenced the reliability of the findings. A multidimensional approach to the role of empathy in counselling may help human services professionals to manage their emotional reactions when they engage in counselling with distressed clients.  相似文献   
3.
We consider additive mixed models for longitudinal data with a nonlinear time trend. As random effects distribution an approximate Dirichlet process mixture is proposed that is based on the truncated version of the stick breaking presentation of the Dirichlet process and provides a Gaussian mixture with a data driven choice of the number of mixture components. The main advantage of the specification is its ability to identify clusters of subjects with a similar random effects structure. For the estimation of the trend curve the mixed model representation of penalized splines is used. An Expectation-Maximization algorithm is given that solves the estimation problem and that exhibits advantages over Markov chain Monte Carlo approaches, which are typically used when modeling with Dirichlet processes. The method is evaluated in a simulation study and applied to theophylline data and to body mass index profiles of children.  相似文献   
4.
Two fundamental axioms in social choice theory are consistency with respect to a variable electorate and consistency with respect to components of similar alternatives. In the context of traditional non‐probabilistic social choice, these axioms are incompatible with each other. We show that in the context of probabilistic social choice, these axioms uniquely characterize a function proposed by Fishburn (1984). Fishburn's function returns so‐called maximal lotteries, that is, lotteries that correspond to optimal mixed strategies in the symmetric zero‐sum game induced by the pairwise majority margins. Maximal lotteries are guaranteed to exist due to von Neumann's Minimax Theorem, are almost always unique, and can be efficiently computed using linear programming.  相似文献   
5.
Urban Ecosystems - Urban agriculture (UA) is regarded as an emerging tool and strategy for sustainable urban development as it addresses a wide array of environmental, economic and social...  相似文献   
6.
Adult Protective Services (APS) professionals are often called on to assess decision-making capacity when investigating financial exploitation. Previous research found that in consecutive APS cases, a decision-making screening scale (LFDSS) also detected financial exploitation. The purpose of this study was to apply the clinical cutoff scores derived from the previous study to a new sample of APS cases. Using a sample of 105 participants, from APS workers across 5 counties this study investigated the clinical utility of the LFDSS to detect financial exploitation based on ratings by APS professionals using the scale. Results demonstrate that the LFDSS has excellent internal consistency and clinical utility properties. This paper provides support for use of the LFDSS as a reliable and valid instrument. Instructions for use of the LFDSS are included in the article, along with information about online support tools.  相似文献   
7.
In explicit persuasion, the communicator states explicitly a desire to persuade the consumer. By referring to an attributional approach, social engagement was simultaneously explored as a beneficial communicator attribute, while cause-related marketing (CRM) was addressed as a boundary condition. In an experiment, we varied the persuasion strategy (explicit vs. implicit), the communicator’s prior experience with social engagement (yes vs. no), and the specific marketing strategy (CRM vs. non-charity marketing). As expected, in the non-charity marketing condition, explicit (vs. implicit) persuasion was more effective when the communicator had prior experience in social engagement. In the CRM condition, explicit (vs. implicit) persuasion was less effective when the communicator had prior experience in social engagement; when no prior experience was reported, persuasiveness increased.  相似文献   
8.
We study prevalence of son preference in families of East and South Asian origin living in the USA by investigating parental time investments in children using American Time Use Surveys. Estimates show that East and South Asian mothers spend an additional hour of quality time per day with their young (aged 0–2 years) sons than with young daughters; son preference in mothers’ time allocation declines as children get older. East and South Asian fathers’ time with young children is gender neutral. We find gender specialization in time with children aged 6–17 with fathers spending more time with sons and mothers spending more time with daughters.  相似文献   
9.
A large body of literature has demonstrated a positive relationship between education and age at first birth. However, this relationship may be partly spurious because of family background factors that cannot be controlled for in most research designs. We investigate the extent to which education is causally related to later age at first birth in a large sample of female twins from the United Kingdom (N = 2,752). We present novel estimates using within–identical twin and biometric models. Our findings show that one year of additional schooling is associated with about one-half year later age at first birth in ordinary least squares (OLS) models. This estimate reduced to only a 1.5-month later age at first birth for the within–identical twin model controlling for all shared family background factors (genetic and family environmental). Biometric analyses reveal that it is mainly influences of the family environment—not genetic factors—that cause spurious associations between education and age at first birth. Last, using data from the Office for National Statistics, we demonstrate that only 1.9 months of the 2.74 years of fertility postponement for birth cohorts 1944–1967 could be attributed to educational expansion based on these estimates. We conclude that the rise in educational attainment alone cannot explain differences in fertility timing between cohorts.  相似文献   
10.
Augmented Reality focuses on the enrichment of the user's natural field of view by consistent integration of text, symbols and interactive three-dimensional objects in real time. Placing virtual objects directly into the user's view in a natural context empowers highly dynamic applications. On the other hand, this necessitates deliberate choice of information design and density, in particular for deployment in hazardous environments like military combat scenarios. As the amount of information needed is not foreseeable and strongly depends on the individual mission, an appropriate system must offer adequate adaptation capabilities. The paper presents a prototypical, vehicle-mountable Augmented Reality vision system, designed for enhancing situation awareness in stressful urban warfare scenarios. Tracking, as one of the most crucial challenges for outdoor Augmented Reality, is accomplished by means of a Differential-GPS approach while the type of display to attach can be modified, ranging from ocular displays to standard LCD mini-screens. The overall concept also includes envisioning of own troops (blue forces), for which a multi-sensor tracking approach has been chosen. As a main feature, the system allows switching between different information categories, focusing on friendly, hostile, unidentified or neutral data. Results of an empirical study on the superiority of an in-view navigation cue approach conclude the paper.  相似文献   
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