全文获取类型
收费全文 | 410篇 |
免费 | 19篇 |
专业分类
管理学 | 73篇 |
民族学 | 2篇 |
人口学 | 34篇 |
理论方法论 | 40篇 |
综合类 | 3篇 |
社会学 | 166篇 |
统计学 | 111篇 |
出版年
2024年 | 1篇 |
2023年 | 4篇 |
2022年 | 4篇 |
2021年 | 4篇 |
2020年 | 20篇 |
2019年 | 20篇 |
2018年 | 29篇 |
2017年 | 23篇 |
2016年 | 23篇 |
2015年 | 18篇 |
2014年 | 25篇 |
2013年 | 62篇 |
2012年 | 38篇 |
2011年 | 17篇 |
2010年 | 14篇 |
2009年 | 16篇 |
2008年 | 12篇 |
2007年 | 10篇 |
2006年 | 19篇 |
2005年 | 6篇 |
2004年 | 7篇 |
2003年 | 4篇 |
2002年 | 9篇 |
2001年 | 7篇 |
2000年 | 5篇 |
1999年 | 2篇 |
1998年 | 4篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 5篇 |
1991年 | 3篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1979年 | 2篇 |
排序方式: 共有429条查询结果,搜索用时 15 毫秒
381.
Vela-Bueno A Fernandez-Mendoza J Olavarrieta-Bernardino S Vgontzas AN Bixler EO de la Cruz-Troca JJ Rodriguez-Muñoz A Oliván-Palacios J 《Journal of American college health : J of ACH》2008,57(2):150-158
Objective: Between November 2002 and March 2003, the authors assessed the prevalence and correlates of napping among Spanish university students. Participants: The sample comprised 1,276 first-year university students; the mean age was 18.74 +/- 1.24 years, and 35.45% were men. Methods: The study was cross-sectional, and the students completed self-report, anonymous questionnaires provided during an in-class survey. Results: Almost half (44%) of the sample reported napping (90% did so after lunch for longer than 1 hour). Multiple logistic regression analysis showed that experiencing an irregular sleep-wakefulness pattern, having a morning school schedule, and being male were significant predictor variables of napping. Further significant outcome variables related to napping were having excessive daytime sleepiness, missing classes because of tiredness, better ability to concentrate later in the afternoon, and a perception of deeper nighttime sleep. Conclusions: Habitual napping is common among Spanish university students and associated with an irregular sleep-wakefulness pattern. Taking long postlunch naps seems to be used by students to cope with insufficient sleep and daytime sleepiness. 相似文献
382.
In this article, we study the behavior of the coefficient of variation (CV) of a random variable that follows a symmetric distribution in the real line. Specifically, we estimate this coefficient using the maximum-likelihood (ML) method. In addition, we provide asymptotic inference for this parameter, which allows us to contrast hypothesis and construct confidence intervals. Furthermore, we produce influence diagnostics to evaluate the sensitivity of the ML estimate of this coefficient when atypical data are present. Moreover, we illustrate the obtained results by using financial real data. Finally, we carry out a simulation study to detect the potential influence of atypical observations on the ML estimator of the CV of a symmetric distribution. The illustration and simulation demonstrate the robustness of the ML estimation of this coefficient. 相似文献
383.
We introduce a dominance intensity measuring method to derive a ranking of alternatives to deal with incomplete information in multi-criteria decision-making problems on the basis of multi-attribute utility theory (MAUT) and fuzzy sets theory. We consider the situation where there is imprecision concerning decision-makers' preferences, and imprecise weights are represented by trapezoidal fuzzy weights. The proposed method is based on the dominance values between pairs of alternatives. These values can be computed by linear programming, as an additive multi-attribute utility model is used to rate the alternatives. Dominance values are then transformed into dominance intensity measures, used to rank the alternatives under consideration. Distances between fuzzy numbers based on the generalization of the left and right fuzzy numbers are utilized to account for fuzzy weights. 相似文献
384.
We introduce the class of bivariate copulas with piecewise linear horizontal sections whose graph is composed, at most, of two segments. It is a wide class of copulas which contains some known copulas. We study several properties of the copulas in the new class concerning absolute continuity, singular components, measures of association, concordance ordering, dependence concepts and symmetry. Finally, we provide several examples. 相似文献
385.
Pat Antonio Goldsmith 《Sociological focus》2013,46(4):439-456
Abstract Durkheim's theory of the causes of specialization in society proposes that the best performers should come from places with the most competitive interaction. This paper tests this proposition in an arena where interaction is highly competitive and where performance can be objectively measured, organized athletics in the United States. Four state-level indicators of competitive interaction (population, population density, average school size, and racial diversity) are used to predict the number of Olympic athletes developing in each state for the Olympic years 1956, 1968, 1980, and 1992. Net of controls for opportunities in athletics, results show that the number of Olympians developing in states increases exponentially with population, average high school size, and racial homogeneity, as Durkheimian theory suggests. These findings are robust even with controls for unmeasured state differences. I conclude that holding constant opportunity, states with more interaction among athletes produce more of the “best.” 相似文献
386.
A new class of nonparametric tests, based on random projections, is proposed. They can be used for several null hypotheses
of practical interest, including uniformity for spherical (directional) and compositional data, sphericity of the underlying
distribution and homogeneity in two-sample problems on the sphere or the simplex.
The proposed procedures have a number of advantages, mostly associated with their flexibility (for example, they also work
to test “partial uniformity” in a subset of the sphere), computational simplicity and ease of application even in high-dimensional
cases. 相似文献
387.
Antonio F. B. Costa 《Journal of applied statistics》2011,38(4):661-673
Measurement error and autocorrelation often exist in quality control applications. Both have an adverse effect on the X¯ chart's performance. To counteract the undesired effect of autocorrelation, we build-up the samples with non-neighbouring items, according to the time they were produced. To counteract the undesired effect of measurement error, we measure the quality characteristic of each item of the sample several times. The chart's performance is assessed when multiple measurements are applied and the samples are built by taking one item from the production line and skipping one, two or more before selecting the next. 相似文献
388.
Stochastic sequential bargaining models (Merlo and Wilson (1995, 1998)) have found wide applications in different fields including political economy and macroeconomics due to their flexibility in explaining delays in reaching an agreement. This paper presents new results in nonparametric identification and estimation of such models under different data scenarios. 相似文献
389.
The Comprehensive Caregiver Choices Program provided support for employee caregivers of elderly people for employees at a hospital in Fort Worth, Texas. Key informant interviews and focus groups provided direction for program development and implementation. A full-time MSW and professionals with expertise in gerontology/geriatrics provided education and care coordination services to caregivers. Approximately 4% of the hospital's workforce participated in the program. Attendees evaluated educational sessions and follow-up interviews were conducted with program participants. Caregiver support programs must continue to seek innovative and creative marketing and service delivery methods to reach out and assist working caregivers in need of support. 相似文献
390.
The problem of approximating an ‘image’ S?? d from a random sample of points is considered. If S is included in a grid of square bins, a plausible estimator of S is defined as the union of the ‘marked’ bins (those containing a sample point). We obtain convergence rates for this estimator and study its performance in the approximation of the border of S. The practical aspects of implementation are discussed, including some technical improvements on the estimator, whose performance is checked through a real data example. 相似文献