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   452篇
  免费   11篇
  国内免费   4篇
管理学   78篇
人口学   9篇
丛书文集   36篇
理论方法论   10篇
综合类   198篇
社会学   18篇
统计学   118篇
  2023年   2篇
  2022年   3篇
  2021年   1篇
  2020年   4篇
  2019年   5篇
  2018年   6篇
  2017年   9篇
  2016年   5篇
  2015年   12篇
  2014年   11篇
  2013年   60篇
  2012年   25篇
  2011年   24篇
  2010年   20篇
  2009年   18篇
  2008年   35篇
  2007年   30篇
  2006年   30篇
  2005年   28篇
  2004年   22篇
  2003年   26篇
  2002年   22篇
  2001年   20篇
  2000年   10篇
  1999年   1篇
  1998年   6篇
  1997年   6篇
  1996年   3篇
  1995年   2篇
  1994年   2篇
  1993年   2篇
  1992年   3篇
  1991年   3篇
  1990年   1篇
  1989年   2篇
  1988年   2篇
  1987年   1篇
  1986年   1篇
  1984年   1篇
  1983年   2篇
  1975年   1篇
排序方式: 共有467条查询结果,搜索用时 62 毫秒
101.
目前我国有几种大型英语测试,如大学英语四、六级考试,英语专业四、八级考试,公共英语等级考试等,这些考试不可避免地存在一些共同的问题,即:考试制度不合理、信度和效度低、考试题型单一、阅卷评分有误差等。就上述问题提出了几点改革的设想。  相似文献   
102.
This paper considers the problem of identifying which treatments are strictly worse than the best treatment or treatments in a one-way layout, which has many important applications in screening trials for new product development. A procedure is proposed that selects a subset of the treatments containing only treatments that are known to be strictly worse than the best treatment or treatments. In addition, simultaneous confidence intervals are obtained which provide upper bounds on how inferior the treatments are compared with these best treatments. In this way, the new procedure shares the characteristics of both subset selection procedures and multiple comparison procedures. Some tables of critical points are provided for implementing the new procedure, and some examples of its use are given.  相似文献   
103.
关联规则挖掘算法是通信网告警相关性分析中的重要方法。在处理数量庞大的告警数据库时,算法的效率显得至关重要,而经典的FP-growth算法会产生大量的条件模式树,加权算法MINWAL(O)则需要多次扫描数据库,使得在通信网环境下挖掘关联规则的难度非常大。该文提出了一种高效的基于加权频繁模式树的通信网告警关联规则挖掘算法,算法性能测试表明,该算法与已有的加权关联规则挖掘算法相比较,节约了大量的存储空间,提高了算法的挖掘速度,对通信网的故障诊断和故障定位有着积极的意义。  相似文献   
104.
The most popular multivariate control chart for monitoring the mean of a distribution is probably the Hotelling T2 rule. Unfortunately, this rule relies on the assumption that the distribution under control is Gaussian, which is rarely true in practice. The objective of this paper is to propose a new approach for the non-normal multivariate case. It consists in the construction of a tolerance region obtained from a density level set estimation. The method follows a “plug-in” approach in which the density of the observations is previously estimated. This estimation is conducted using copulas modeling, an increasingly popular tool in multivariate modeling.  相似文献   
105.
In this article, a variable selection procedure, called surrogate selection, is proposed which can be applied when a support vector machine or kernel Fisher discriminant analysis is used in a binary classification problem. Surrogate selection applies the lasso after substituting the kernel discriminant scores for the binary group labels, as well as values for the input variable observations. Empirical results are reported, showing that surrogate selection performs well.  相似文献   
106.
In this paper, we give a lower bound for the number of treatments required

for a plan to be a main effect plus one plan for 2m (m = 6) factorial experiments, The lower bound problem is important in the event of generating new designs with similar properties or when one wants to study the criteria of optimality for such designs.  相似文献   
107.
Data envelopment analysis (DEA) is a non-parametric approach for measuring the relative efficiencies of peer decision making units (DMUs). Many studies have examined DEA efficiencies of two-stage systems, where all the outputs from the first stage are the only inputs to the second stage. Although single-stage DEA models with undesirable input-outputs have been extensively studied, there still lacks of more systematical investigation on two-stage DEA with undesirable variables. For instance, depending on its operating model, even whether an intermediate variable is desirable or undesirable can be questionable for a particular two-stage system. Furthermore, most of the existing studies on two-stage systems focus on the case where only the final outputs are undesirable. In this work, we try to systematically examine two-stage DEA models with undesirable input-intermediate-outputs. Particularly, we utilize the free-disposal axioms to construct the production possibility sets (PPS) and the corresponding DEA models with undesirable variables. The proposed models are then used to illustrate some theoretical perspectives by using the data of China׳s listed banks.  相似文献   
108.
Ji Hwan Cha 《Statistics》2015,49(5):1141-1156
Traditionally, acceptance reliability sampling plans have been developed for non-repairable items. However, the functions required for items become more and more complex and, accordingly, the items are composed of several components and tend to be repairable. In this paper, we consider variables acceptance reliability sampling plan for repairable items. We develop a variables acceptance sampling plan based on the failure and repair data observed during the testing period. It is shown that the developed sampling plan improves the reliability characteristic of the population and that the lifetimes of items before and after the reliability sampling test are stochastically ordered.  相似文献   
109.
Poverty can be seen as a multidimensional phenomenon described by a set of indicators, the poverty components. A one-dimensional measure of poverty serving as a ranking index can be obtained by combining the component indicators via aggregation techniques. Ranking indices are thought of as supporting political decisions. This paper proposes an alternative to aggregation based on simple concepts of partial order theory and illustrates the pros and cons of this approach taking as case study a multidimensional measure of poverty comprising three components – absolute poverty, relative poverty and income – computed for the European Union regions. The analysis enables one to highlight conflicts across the components with some regions detected as controversial, with, for example, low levels of relative poverty and high levels of monetary poverty. The partial order approach enables one to point to the regions with the most severe data conflicts and to the component indicators that cause these conflicts.  相似文献   
110.
跨文化视野下的学科会聚   总被引:2,自引:0,他引:2  
学科的交叉和会聚需要理论的支撑.它包括三个方面的内容:(1)中心项(Central Item),学科会聚与交叉必有一个主要的领域、学科或学说,这是确定首席专家的依据;(2)关联域(Context),即构成该学科会聚的以中心项为主的相关领域,这是确定准入人员、准入项目的依据;(3)学科间性(Inter-disciplinity),这是学科交叉会聚所产生的新的质素,即新的前沿性领域、新的关节点,也是学科会聚所要探索的新知识.一个新的科研群体是否有前景、有地位,主要取决于对"学科间性"这一新的知识宝库的把握程度.学科会聚背后是人才的会聚,而人才会聚时所释放出的凝聚力或离心力都远远大于一般素质的人员,因而除了科研群体的共同信念外,上述三个理论可以说也是处理科研群体人事关系的依据.此外,还必须有共同的跨文化的视野.因为学科的分化是在希腊及近代的西方文化语境下发生的,而学科的交叉与会聚已超出单一的语境.凝聚于一个群体的学者有不同的文化背景;作为研究对象的客体,有的涉及不同文化的价值认同(例如生命科学、环境问题).特别是人文社会科学或者人文社会科学与自然科学的交叉学科,有无跨文化的视野可以说是研究成败的关键因素之一.  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