首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   194篇
  免费   7篇
管理学   22篇
民族学   6篇
人口学   25篇
丛书文集   1篇
理论方法论   13篇
社会学   41篇
统计学   93篇
  2023年   6篇
  2022年   2篇
  2021年   3篇
  2020年   6篇
  2019年   18篇
  2018年   15篇
  2017年   6篇
  2016年   15篇
  2015年   9篇
  2014年   8篇
  2013年   48篇
  2012年   9篇
  2011年   3篇
  2010年   4篇
  2009年   7篇
  2008年   2篇
  2007年   6篇
  2006年   7篇
  2005年   1篇
  2004年   3篇
  2003年   1篇
  2002年   2篇
  2001年   3篇
  1997年   1篇
  1995年   1篇
  1994年   2篇
  1993年   2篇
  1991年   2篇
  1989年   2篇
  1983年   2篇
  1980年   2篇
  1979年   1篇
  1977年   1篇
  1970年   1篇
排序方式: 共有201条查询结果,搜索用时 15 毫秒
71.
We examine the impact of geographic location on the level and structure of executive compensation of small and medium enterprises (SMEs) in Canada, using a panel data sample between 2008 and 2011. Our results show that SMEs pay a higher price for talent by paying a large proportion (71%) of compensation as guaranteed cash pay to their executives. We also report a strong influence of location on compensation structure. Specifically, rural firms pay 13% more incentive based equity pay to their executives compared to their size matched urban counterparts. However, there is no difference between the total compensation for managers of rural and urban firms after controlling for the cost of living index. In cross-sectional tests, we observe that total compensation is positively related to CEO/Chair duality and family ownership but is not related to management quality. In addition, we find that rural firms display a higher pay-performance sensitivity.  相似文献   
72.
The existence of a discontinuity in a regression function can be inferred by comparing regression estimates based on the data lying on different sides of a point of interest. This idea has been used in earlier research by Hall and Titterington (1992), Müller (1992) and later authors. The use of nonparametric regression allows this to be done without assuming linear or other parametric forms for the continuous part of the underlying regression function. The focus of the present paper is on assessing the evidence for the presence of a discontinuity within a regression function through examination of the standardised differences of ‘left’ and ‘right’ estimators at a variety of covariate values. The calculations for the test are carried out through distributional results on quadratic forms. A graphical method in the form of a reference band to highlight the sources of the evidence for discontinuities is proposed. The methods are also developed for the two covariate case where there are additional issues associated with the presence of a jump location curve. Methods for estimating this curve are also developed. All the techniques, for the one and two covariate situations, are illustrated through applications.  相似文献   
73.
Utilizing studies which validate voter turnout, previous researchershave been able to identify a strong tendency for individualsto report voting when they in fact did not. In this article,we assess the effectiveness of a new turnout question on reducingvoter over-reporting in the National Election Study. Providingrespondents with socially acceptable excuses for not voting,we found that this alternate question significantly reducesthe over-reporting of turnout in the 2002 National ElectionStudy by about 8 percentage points. Moreover, our analysis revealsthat with the new question wording, estimates of the turnoutrate for those usually thought to be the least likely to voteare considerably lower than estimates using the traditionalquestion. Thus, not only did the experiment work to significantlyreduce over-reporting, the new question provides deeper insightsinto the voting behavior of the American electorate that hasimplications for both scholars and reformers.  相似文献   
74.
Urban biodiversity management in most African countries is at a peripheral stage. At the same time, African urban areas substantially remain poorly planned and intensively growing. This study explores the socio-ecological system as an alternative approach to explore African indigenous urban biodiversity management. For this purpose, we mixed conventional scientific investigation methods to explain the biodiversity conservation in the ancient gardens of the Kano palace in northern Nigeria. This multidisciplinary approach has successfully unveiled a harmonious relationship of humans and ecosystems in the context of African cultural values and heritage systems. The paper reveals that the palace gardens offer an avenue for intersection of a wide range of ecological and cultural activities. These include biodiversity conservation, recreation, security and surveillance, climate hazards proofing, and sacred dimensions. The findings of this study show that it is possible to address challenges confronting Africa’s urban biodiversity through the combination of scientific and indigenous systems.  相似文献   
75.
This article considers the shrinkage estimation procedure in the Cox's proportional hazards regression model when it is suspected that some of the parameters may be restricted to a subspace. We have developed the statistical properties of the shrinkage estimators including asymptotic distributional biases and risks. The shrinkage estimators have much higher relative efficiency than the classical estimator, furthermore, we consider two penalty estimators—the LASSO and adaptive LASSO—and compare their relative performance with that of the shrinkage estimators numerically. A Monte Carlo simulation experiment is conducted for different combinations of irrelevant predictors and the performance of each estimator is evaluated in terms of simulated mean squared error. Simulation study shows that the shrinkage estimators are comparable to the penalty estimators when the number of irrelevant predictors in the model is relatively large. The shrinkage and penalty methods are applied to two real data sets to illustrate the usefulness of the procedures in practice.  相似文献   
76.
Newton's binomial series expansion is used to develop a (class of) distribution function(s) Fr:∝ which may be interpreted as the distribution of the rthorder statistic with nonintegral sample size∝. It is shown that Fr:∝ has properties similar to Fr:n. Multivariate extension is considered and an elementary proof of the integral representation for the joint distribution of a subset of order statistics is given. An application is included.  相似文献   
77.
This article considers estimation of the slope parameter of the linear regression model with Student-t errors in the presence of uncertain prior information on the value of the unknown slope. Incorporating uncertain non sample prior information with the sample data the unrestricted, restricted, preliminary test, and shrinkage estimators are defined. The performances of the estimators are compared based on the criteria of unbiasedness and mean squared errors. Both analytical and graphical methods are explored. Although none of the estimators is uniformly superior to the others, if the non sample information is close to its true value, the shrinkage estimator over performs the rest of the estimators.  相似文献   
78.
Dealing with stationarity remains an unsolved problem. Some of the time series data, especially crude palm oil (CPO) prices persist towards nonstationarity in the long-run data. This dilemma forces the researchers to conduct first-order difference. The basic idea is that to obtain the stationary data that is considered as a good strategy to overcome the nonstationary counterparts. An opportune remark as it is, this proxy may lead to overdifference. The CPO prices trend elements have not been attenuated but nearly annihilated. Therefore, this paper presents the usefulness of autoregressive fractionally integrated moving average (ARFIMA) model as the solution towards the nonstationary persistency of CPO prices in the long-run data. In this study, we employed daily historical Free-on-Board CPO prices in Malaysia. A comparison was made between the ARFIMA over the existing autoregressive-integrated moving average (ARIMA) model. Here, we employed three statistical evaluation criteria in order to measure the performance of the applied models. The general conclusion that can be derived from this paper is that the usefulness of the ARFIMA model outperformed the existing ARIMA model.  相似文献   
79.
A data-driven technique is proposed to estimate the trend and relative growth rate of time series data. The method is based on the local linear regression smoother and the only assumption about the form of the trend and growth rate function is that they are smooth functions of time. We also extended the method for handling sudden shifts or changes in the trend or growth rate functions by adding dummy variables for the jumps. Simulation studies are carried out to see the performance of the proposed procedure. The method is applied to study the trend and growth rate of wheat production in India from 1951–2005.  相似文献   
80.
We propose a novel approach to estimation, where a set of estimators of a parameter is combined into a weighted average to produce the final estimator. The weights are chosen to be proportional to the likelihood evaluated at the estimators. We investigate the method for a set of estimators obtained by using the maximum likelihood principle applied to each individual observation. The method can be viewed as a Bayesian approach with a data-driven prior distribution. We provide several examples illustrating the new method and argue for its consistency, asymptotic normality, and efficiency. We also conduct simulation studies to assess the performance of the estimators. This straightforward methodology produces consistent estimators comparable with those obtained by the maximum likelihood method. The method also approximates the distribution of the estimator through the “posterior” distribution.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号