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   653篇
  免费   37篇
管理学   73篇
民族学   6篇
人口学   70篇
理论方法论   47篇
综合类   4篇
社会学   289篇
统计学   201篇
  2024年   1篇
  2023年   16篇
  2022年   9篇
  2021年   2篇
  2020年   14篇
  2019年   24篇
  2018年   49篇
  2017年   68篇
  2016年   49篇
  2015年   27篇
  2014年   25篇
  2013年   124篇
  2012年   64篇
  2011年   23篇
  2010年   20篇
  2009年   26篇
  2008年   24篇
  2007年   6篇
  2006年   19篇
  2005年   32篇
  2004年   20篇
  2003年   9篇
  2002年   8篇
  2001年   2篇
  2000年   5篇
  1999年   4篇
  1998年   1篇
  1996年   2篇
  1994年   2篇
  1993年   3篇
  1992年   1篇
  1991年   2篇
  1990年   2篇
  1989年   2篇
  1986年   1篇
  1985年   1篇
  1984年   1篇
  1983年   1篇
  1969年   1篇
排序方式: 共有690条查询结果,搜索用时 15 毫秒
101.
ABSTRACT

Panel datasets have been increasingly used in economics to analyze complex economic phenomena. Panel data is a two-dimensional array that combines cross-sectional and time series data. Through constructing a panel data matrix, the clustering method is applied to panel data analysis. This method solves the heterogeneity question of the dependent variable, which belongs to panel data, before the analysis. Clustering is a widely used statistical tool in determining subsets in a given dataset. In this article, we present that the mixed panel dataset is clustered by agglomerative hierarchical algorithms based on Gower's distance and by k-prototypes. The performance of these algorithms has been studied on panel data with mixed numerical and categorical features. The effectiveness of these algorithms is compared by using cluster accuracy. An experimental analysis is illustrated on a real dataset using Stata and R package software.  相似文献   
102.
In this paper a test statistic which is a modification of the W statistic for testing the goodness of fit for the two paremeter extreme value (smallest element) distribution is proposed. The test statistic Is obtained as the ratio of two linear estimates of the scale parameter. It Is shown that the suggested statistic is computationally simple and has good power properties. Percentage points of the statistic are obtained by performing Monte Carlo experiments. An example is given to illustrate the test procedure.  相似文献   
103.
Statistical procedures for the detection of a change in the dependence structure of a series of multivariate observations are studied in this work. The test statistics that are proposed are $L_1$ , $L_2$ , and $L_{\infty }$ distances computed from vectors of differences of Kendall's tau; two multivariate extensions of Kendall's measure of association are used. Since the distributions of these statistics under the null hypothesis of no change depend on the unknown underlying copula of the vectors, a procedure based on the multiplier central limit theorem is used for the computation of p‐values; the method is shown to be valid both asymptotically and for moderate sample sizes. Alternative versions of the tests that take into account possible breakpoints in the marginal distributions are also investigated. Monte Carlo simulations show that the tests are powerful under many scenarios of change‐point. In addition, two estimators of the time of change are proposed and their efficiency is carefully studied. The methodologies are illustrated on simulated series from the Canadian Regional Climate Model. The Canadian Journal of Statistics 41: 65–82; 2013 © 2012 Statistical Society of Canada  相似文献   
104.
The present study aims to develop an index composed of different spatial variables to measure the urban sprawl levels of a municipality located in Southern Spain. According to the findings, urban sprawl can be measured not only on the metropolitan level but also on a more detailed and precise level, such as sub-municipal. A group of experts chosen for their suitability in measuring urban sprawl select six spatial variables (population density, net residential density, coverage ratio, land use types, percentage of residential land use, and average year of construction). These variables are aggregated using Choquet integral, a technique that combines interactions between those variables providing greater coherence to the complexity that is inherent in the creation of composite sprawl indexes. This methodology has been demonstrated to be valid and appropriate in evaluating urban expansion at sub-municipal level, but can also be applied to other scales once it is clearly a phenomenon in which interaction between criteria exists. The resulting composite index allows the assignment of different levels of sprawl to the urban areas consistent with their morphology and landscape.  相似文献   
105.
106.
In this article, we join the discussion about the potential consequences of welfare service privatization by examining the relationship between the privatization of welfare service delivery and public opinion about service quality in Sweden. Due to the politically polarized debate about welfare service privatization in Sweden, we also examine the extent to which individualsapos; ideological orientations influence this relationship in both local politicians and ordinary citizens. For local politicians, the results show that a higher municipal degree of privatization is generally associated with slightly lower levels of satisfaction overall with welfare services, although no such relationship exists for the public. Most importantly, however, the results indicate that political ideology constitutes an important moderator in the relationship between privatization and opinions about service quality. Local politicians and, to some extent, ordinary citizens who place themselves to the left on the ideological left–right scale tend to be less satisfied with services as the municipal degree of welfare service privatization increases. For local politicians who position themselves far to the right on the scale, the relationship between welfare service privatization and satisfaction is positive. These findings suggest that there is no clear-cut relationship between privatization and individualsapos; opinions about services; rather, this relationship depends on the ideological predispositions of local politicians and ordinary citizens.  相似文献   
107.
Starting from the idea that relational sociology has been founded on various and incompatible social ontologies, I argue that it is at risk of losing its raison d'être if we do not answer two fundamental practical and ontological questions: (1) Why do we need relational sociology? and (2) What do we study in relational sociology? In this respect, I propose a deep, transactional sociology partly and freely inspired by the work of J. Dewey which clearly detaches relational sociology from social determinism and co-determinism.  相似文献   
108.

This study seeks to evaluate whether interorganizational trust and interpersonal trust influence the nature of state control in Brazilian public/non-profit partnerships (PNPs) by considering the social organization model with a non-profit partner that did not evolve organically from civil society as an equal and interdependent partner but instead was engineered by the state. We conducted qualitative research on two PNPs and analysed their historical trajectories through participant observation, documentary analysis and semi-structured interviews with the state and non-profit partners as well as other actors involved indirectly in the PNPs. Our findings call into question the assumption of current studies that trust tends to be built over time and reveal that PNPs embedded in state-dominant and low-social-capital contexts are more vulnerable to the effects of interpersonal trust. This vulnerability influences the volatile patterns of the PNPs’ trajectories and leads to strong informal state-partner control as reflected by PNP disruptions and lower levels of interorganizational trust.

  相似文献   
109.
We investigate divisions within the citation network in economics using citation data between 1990 and 2010. We consider all partitions of top institutions into two equal‐sized clusters and pick the one that minimizes cross‐cluster citations. The strongest division is much stronger than could be expected to be found under idiosyncratic citation patterns and is consistent with the reputed freshwater/saltwater division in macroeconomics. The division is stable over time but varies across the fields of economics. (JEL A11, D85, I23)  相似文献   
110.
Background: The prevalence rates for both sarcopenia and erectile dysfunction (ED) gradually increase in middle-aged and elderly diabetic male population and they impair physical functioning, sexual functioning, and quality of life. The aim of the present study was to evaluate the sarcopenia in patients with diabetic ED.

Methods: The study included 98 male patients with type II diabetes mellitus (DM) aged 18–80?years. Blood chemistry and hormone levels were obtained. The International Index of Erectile Function (IIEF-5) questionnaire was administered to the patients. The patients were divided into three groups according to the IIEF-5 score; a score of 5–10 points indicated severe ED, a score of 11–20 indicated moderate ED, and a score of 21–25 points indicated no ED. The muscle mass, handgrip strength, timed up and go test, upper mid-arm circumference, calf circumference, and body mass index were obtained. The statistical analysis was performed using MedCalc Statistical Software version 12.7.7. All parameters were compared between the three groups.

Results: Of 98 patients included in the study, 84 patients had severe sarcopenia, 13 had moderate sarcopenia, while only one patient had normal muscle mass. The mean age was 56.59?±?11.46?years. When patients were divided into three groups according to IIEF-5 score, 38 had severe ED, 39 had moderate ED, and 21 had no ED. There was a significant difference between the three groups in terms of handgrip strength, timed up and go test scores, upper mid-arm circumference, and calf circumference (p?Conclusions: Although muscle mass remains unchanged, muscle strength and physical performance decrease in diabetic ED patients. Diabetic patients with severe and moderate ED have lower muscle strength and physical performance.  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