排序方式: 共有36条查询结果,搜索用时 15 毫秒
21.
Elena J. Tenenbaum Rajesh J. Shah David M. Sobel Bertram F. Malle James L. Morgan 《Infancy》2013,18(4):534-553
This study examines face‐scanning behaviors of infants at 6, 9, and 12 months as they watched videos of a woman describing an object in front of her. The videos were created to vary information in the mouth (speaking vs. smiling) and the eyes (gazing into the camera vs. cueing the infant with head turn or gaze direction to an object being described). Infants tended to divide their attention between the eyes and the mouth, looking less at the eyes with age and more at the mouth than the eyes at 9 and 12 months. Attention to the mouth was greater on speaking trials than on smiling trials at all three ages, and this difference increased between 6 and 9 months. Despite consistent results within subjects, there was considerable variation between subjects. This raises the question of whether a developmental “norm” of face scanning in infancy ought to be pursued. Rather, these data add to emerging evidence suggesting that individual differences in face scanning might reliably predict aspects of later development. 相似文献
22.
The objective of this paper is to construct an unbiased estimator (up to order 0(1/n)) of the population mean
of the study variatey which is more efficient than the sample mean
of the ‘n’ obsrvedy-values. In particular, the unbiased estimators are discussed for the cases of positive and negative correlations of the study
variatey and the auxiliary variatex. 相似文献
23.
This article proposes Hartley-Ross type unbiased estimators of finite population mean using information on known parameters of auxiliary variate when the study variate and auxiliary variate are positively correlated. The variances of the proposed unbiased estimators are obtained. It has been shown that the proposed estimators are more efficient than the simple mean estimator, usual ratio estimator and estimators proposed by Sisodia and Dwivedi (1981), Kadilar and Cingi (2006), and Kadilar et al. (2007) under certain realistic conditions. Empirical studies are also carried out to demonstrate the merits of the proposed unbiased estimators over other estimators considered in this article. 相似文献
24.
Kali S. Thomas Danielle Cote Rajesh Makineni Orna Intrator Bruce Kinosian Ciaran S. Phibbs 《Journal of aging & social policy》2018,30(2):93-108
The United States Department of Veterans Affairs (VA) is facing pressures to rebalance its long-term care system. Using VA administrative data from 2004–2011, we describe changes in the VA’s nursing homes (called Community Living Centers [CLCs]) following enactment of directives intended to shift CLCs’ focus from providing long-term custodial care to short-term rehabilitative and post-acute care, with safe and timely discharge to the community. However, a concurrent VA hospice and palliative care expansion resulted in an increase in hospice stays, the most notable change in type of stay during this time period. Nevertheless, outcomes for Veterans with non-hospice short and long stays, such as successful discharge to the community, improved. We discuss the implications of our results for simultaneous implementation of two initiatives in VA CLCs. 相似文献
25.
This paper discusses the problem of estimation of population mean in case of post-stratification. Improved ratio- and product-type exponential estimators of finite population mean are suggested with their case of post-stratification. Bias and mean-squared error of the suggested estimators are obtained up to the first degree of approximation. Suggested estimators have been compared with unbiased estimator, ratio estimator, and product estimator in case of post-stratification. An empirical study has been carried out to demonstrate the performance of the suggested estimator. 相似文献
26.
In the present paper, we propose non parametric estimators for the inaccuracy measure for the lifetime distribution based on censored data. This measure plays important roles in reliability and survival analysis in connection with modeling and analysis of life time data. Asymptotic properties of the estimators are established under suitable regularity conditions. Monte Carlo simulation studies are carried out to compare the performance of the estimators using the mean-squared error. The methods are illustrated using a real data set. 相似文献
27.
Recently, Abbasnejad et al. (2010) proposed a measure of uncertainty based on survival function, called the survival entropy of order α. A dynamic form of the survival entropy of order α is also proposed by them. In this paper, we derive the weighted form of these measures. The properties of the new measures are also discussed. 相似文献
28.
Rajesh T.P. Ballullaya U. Prashanth Unni Anjana P. Parvathy Surendran Sinu Palatty Allesh 《Urban Ecosystems》2020,23(6):1335-1348
Urban Ecosystems - Urbanization is a major threat to native biodiversity. Invasion of tramp species is a major consequence of urbanization, which might threaten native species. Ants are established... 相似文献
29.
Wei Zhao Paolo Vicini Steven Novick Judith Anderton Gareth Davies Gina DAngelo Terrance O'Day Binbing Yu Jay Harper Rajesh Narwal Lorin Roskos Harry Yang 《Pharmaceutical statistics》2019,18(6):688-699
Linear models are generally reliable methods for analyzing tumor growth in vivo, with drug effectiveness being represented by the steepness of the regression slope. With immunotherapy, however, not all tumor growth follows a linear pattern, even after log transformation. Tumor kinetics models are mechanistic models that describe tumor proliferation and tumor killing macroscopically, through a set of differential equations. In drug combination studies, although an additional drug‐drug interaction term can be added to such models, however, the drug interactions suggested by tumor kinetics models cannot be translated directly into synergistic effects. We have developed a novel statistical approach that simultaneously models tumor growth in control, monotherapy, and combination therapy groups. This approach makes it possible to test for synergistic effects directly and to compare such effects among different studies. 相似文献
30.
In this paper, efficient class of estimators for population mean using two auxiliary variates is suggested. It has been shown that the suggested estimator is more efficient than usual unbiased estimator in stratified random sampling, usual ratio and product-type estimators, Tailor and Lone (2012, 2014) estimators, and other considered estimators. The bias and mean-squared error of the suggested estimator are obtained up to the first degree of approximation. Conditions under which the suggested estimator is more efficient than other considered estimators are obtained. An empirical study has been carried out to demonstrate the performances of the suggested estimator. 相似文献