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   1581篇
  免费   40篇
管理学   281篇
民族学   5篇
人口学   173篇
丛书文集   13篇
理论方法论   153篇
综合类   6篇
社会学   782篇
统计学   208篇
  2020年   12篇
  2019年   25篇
  2018年   22篇
  2017年   41篇
  2016年   27篇
  2015年   26篇
  2014年   25篇
  2013年   254篇
  2012年   36篇
  2011年   35篇
  2010年   34篇
  2009年   40篇
  2008年   50篇
  2007年   49篇
  2006年   44篇
  2005年   43篇
  2004年   59篇
  2003年   36篇
  2002年   41篇
  2001年   34篇
  2000年   36篇
  1999年   37篇
  1998年   28篇
  1997年   25篇
  1996年   28篇
  1995年   34篇
  1994年   36篇
  1993年   28篇
  1992年   26篇
  1991年   20篇
  1990年   16篇
  1989年   14篇
  1988年   15篇
  1987年   22篇
  1986年   16篇
  1985年   31篇
  1984年   25篇
  1983年   26篇
  1982年   25篇
  1981年   20篇
  1980年   15篇
  1979年   12篇
  1978年   19篇
  1977年   19篇
  1976年   13篇
  1975年   16篇
  1974年   19篇
  1970年   8篇
  1968年   7篇
  1967年   7篇
排序方式: 共有1621条查询结果,搜索用时 46 毫秒
101.
Donald V Mathusz 《Omega》1977,5(5):593-604
Cost-benefit analysis has a considerable literature in which information systems have been patently ignored. This reflects the considerable difficulties of applying the theory to information systems, and the state-of-the art remains relatively as Koopmans described it some 19 years ago (1957). A bar to further development would appear to be the lack of an applicable value-of-information concept. This paper seeks to clarify the issues and provide a robust theoretical and data analysis framework that will cover most situations. The approach here is to separate explicitly the dimensions of cost from those of information benefit, and examine the implications. The Null Information Benefit condition emerges as a special theoretical case, but potentially a most important one in applications. This case together with the Pareto optimum defines a large class of such problems that can be handled by the decision criteria and data analysis techniques tabulated and discussed here. The selection of input data techniques defines the limits of later project justification and may be crucial to the political viability of the projects throughout its life. Finally, the general management vs information systems management relationships are discussed in terms of this situation.  相似文献   
102.
103.
104.
Using exploratory data analysis, probability plots, scatterplots, and computer animations to rotate and visualize the data, we fit a trivariate Normal distribution to data for the height, the natural logarithm of body weight, and the body fat for 646 men between the ages of 50 and 80 years as reported by the medical staff of the U.S. Veterans Administration's “Normative Aging Study” in Boston, MA. Although these data do not include any children, women, or young men, the measurements represent the best data that we could find through a 4-year search. We believe that these data are well measured and reliable for men in the specified age range and that these data reveal an interesting statistical pattern for use in probabilistic PBPK models.  相似文献   
105.
106.
Many important regulatory decisions are taken by professionals employing limited and conflicting evidence. We conduct an experiment in a merger regulation setting, identifying the role of different standards of proof, volumes of evidence, cost of error and professional or lay decision making. The experiment was conducted on current practitioners from 11 different jurisdictions, in addition to student subjects. Legal standards of proof significantly affect decisions. There are specific differences because of professional judgment, including in how error costs and volume of evidence are taken into account. We narrow the range of explanations for why professional decision making matters.  相似文献   
107.
108.
We develop statistical inferential tools for estimating and comparing conditional tail expectation (CTE) functions, which are of considerable interest in actuarial science. In particular, we construct estimators for the CTE functions, develop the necessary asymptotic theory for the estimators, and then use the theory for constructing confidence intervals and bands for the functions. Both parametric and non-parametric approaches are explored. Simulation studies illustrate the performance of estimators in various situations. Results are obtained under minimal assumptions, and the general Vervaat process plays a crucial role in achieving these goals.  相似文献   
109.
Forty children with prelingual, profound deafness who received the Nucleus multichannel cochlear implant between the ages of 2 and 13 years participated in this study. The children had an average of 63.3 months (SD=24 months) of experience with their cochlear implants. A majority of the children used simultaneous communication and attended public-school programs at the time of testing. Reading achievement was assessed using the Paragraph Comprehension subtest of the Woodcock Reading Mastery Test-Revised, Form G (1987). This study compared the reading-achievement levels of this group of cochlear-implant users with the results of previous studies of children with profound hearing losses who did not have the benefit of cochlear implants. Results indicated that nearly one half of the children in this study were reading at or within 8 months of their grade level. The reading-grade quotient of .74 was calculated based upon the slope of the regression line for the plot of years in school and reading grade-level achieved. This finding indicates that using a cochlear implant has a positive effect on reading achievement level.  相似文献   
110.
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