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Lubomir Dechevsky 《Statistics》2013,47(5):423-442
The spatially inhomogeneous smoothness of the non-parametric density or regression-function to be estimated by non-parametric methods is often modelled by Besov- and Triebel-type smoothness constraints. For such problems, Donoho and Johnstone [D.L. Donoho and I.M. Johnstone, Minimax estimation via wavelet shrinkage. Ann. Stat. 26 (1998), pp. 879–921.], Delyon and Juditsky [B. Delyon and A. Juditsky, On minimax wavelet estimators, Appl. Comput. Harmon. Anal. 3 (1996), pp. 215–228.] studied minimax rates of convergence for wavelet estimators with thresholding, while Lepski et al. [O.V. Lepski, E. Mammen, and V.G. Spokoiny, Optimal spatial adaptation to inhomogeneous smoothness: an approach based on kernel estimators with variable bandwidth selectors, Ann. Stat. 25 (1997), pp. 929–947.] proposed a variable bandwidth selection for kernel estimators that achieved optimal rates over Besov classes. However, a second challenge in many real applications of non-parametric curve estimation is that the function must be positive. Here, we show how to construct estimators under positivity constraints that satisfy these constraints and also achieve minimax rates over the appropriate smoothness class. 相似文献
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Nicolas Guéguen Lubomir Lamy 《Journal Of Human Behavior In The Social Environment》2013,23(3):383-387
Previous research found that survey response rates were influenced by physical characteristics of the interviewer. However, the effect of hair color on compliance to a survey request has never been studied. Female confederates wearing blond, brown, black, or red wigs solicited 1,200 male and female pedestrians for a survey. It was found those male passersby, but not the female, agreed more frequently to the confederates wearing blond wigs whereas they agreed less to the same confederates wearing red wigs. Greater youth and healthiness associated with blond hair in women is used to explain these results. The practical interest in face-to-face surveys is addressed. 相似文献
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Nicolas Guéguen Lubomir Lamy Jacques Fischer-Lokou 《Journal Of Human Behavior In The Social Environment》2018,28(2):193-203
It has been reported that familiarity or incidental similarities with a stranger influenced an individual’s behavior. However, the effect of the sense of geographical proximity believing that someone comes from the same area that somebody has never been examined. Three field experiments examined this effect on donations to humanitarian organizations. In the first study, participants were asked by a confederate to donate food products to a humanitarian organization. In Study 2, participants were asked by confederates to donate money for children. In Study 3, donation boxes were displayed in bakeries with a message that invited customers to donate money for children. In all the studies, participants were led to believe that they would be helping people in need or people who live in their national or local geographic area. Results showed that donations were higher in the geographical proximity condition. This “neighborhood effect” was discussed. 相似文献
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Lubomir Lamy Nicolas Guéguen Jacques Fischer-Lokou Jérôme Guegan 《Social Influence》2016,11(2):130-139
Three experiments were conducted in field settings. It was hypothesized that luxury stores may act as environmental reminders of materialism and that helpfulness would vary according to the presence or absence of such cues. Study 1 (N = 80) indicated that consumers coming out of famous brand stores displayed less helpfulness, as compared to mere passersby. Study 2 (N = 112) showed passersby were less helpful near a luxury brand store than in an ordinary street with no shops. In Study 3 (N = 360), passersby were less helpful when walking down a street lined with highly exclusive stores, as compared to streets with ordinary stores or no stores. Results, limitations, and directions for future research are discussed. 相似文献
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Petr Macek Constance Flanagan Leslie Gallay Lubomir Kostron Luba Botcheva & Beno Csapo 《The Journal of social issues》1998,54(3):547-561
This article examines adolescents' perceptions of the economic changes and the justice of the new social contract in Eastern/Central Europe. Focusing on three countries, Hungary, Bulgaria, and the Czech Republic, it explores the social, political, and economic environments in which adolescents came of age in 1990. Surveys conducted among high school students in each country during 1995 tapped their perceptions of the economy, the local community, and their personal beliefs about the efficacy of individual initiative and hard work. Responses differed significantly based on age, gender, social class, value orientation, and country. Older adolescents and girls were more likely to observe that economic disparities were growing in their country and to be cynical about the value of hard work. Those with socialist values also discounted the value of recent changes. Adolescents in the Czech Republic were the least cynical about economic changes, whereas those in Bulgaria were the most cynical, with Hungarian youth the least optimistic about the future. 相似文献
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