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   993篇
  免费   66篇
  国内免费   3篇
管理学   212篇
民族学   2篇
人才学   2篇
人口学   28篇
丛书文集   34篇
理论方法论   20篇
综合类   250篇
社会学   75篇
统计学   439篇
  2024年   1篇
  2023年   4篇
  2022年   7篇
  2021年   23篇
  2020年   34篇
  2019年   37篇
  2018年   36篇
  2017年   45篇
  2016年   39篇
  2015年   43篇
  2014年   57篇
  2013年   166篇
  2012年   64篇
  2011年   59篇
  2010年   37篇
  2009年   48篇
  2008年   62篇
  2007年   33篇
  2006年   48篇
  2005年   36篇
  2004年   31篇
  2003年   21篇
  2002年   31篇
  2001年   21篇
  2000年   16篇
  1999年   11篇
  1998年   8篇
  1997年   9篇
  1996年   6篇
  1995年   8篇
  1994年   3篇
  1993年   1篇
  1992年   4篇
  1991年   3篇
  1990年   4篇
  1989年   2篇
  1988年   2篇
  1987年   1篇
  1982年   1篇
排序方式: 共有1062条查询结果,搜索用时 15 毫秒
11.
制造业项目结构分解过程模型研究   总被引:2,自引:0,他引:2  
针对项目分解中工作分解结构方法的不足,以制造业项目为例,考虑项目产品本身的构造及特点的基础上,综合项目产品的工艺装配过程、产品数据管理技术以及项目组织结构,构建了项目结构分解的过程模型,并对该模型进行了详细分析,应用该模型能够更加科学、合理地进行项目分解,确定项目范围。  相似文献   
12.
本文首先讨论P3、P3e/c项目管理软件与企业管理信息系统集成的必要性和重要性,然后详细地介绍了采用RA引擎(OLE对象)技术来实现P3软件与企业管理信息系统的数据交换,以及与P3e/c交互的原理。分析P3、P3e/c在数据组织上的差异,提出解决方案。最后以实例讨论和分析了这种方法在实际系统中的应用。  相似文献   
13.
Since the seminal work of Pawlak (International Journal of Information and Computer Science, 11 (1982) 341–356) rough set theory (RST) has evolved into a rule-based decision-making technique. To date, however, relatively little empirical research has been conducted on the efficacy of the rough set approach in the context of business and finance applications. This paper extends previous research by employing a development of RST, namely the variable precision rough sets (VPRS) model, in an experiment to predict between failed and non-failed UK companies. It also utilizes the FUSINTER discretisation method which neglates the influence of an ‘expert’ opinion. The results of the VPRS analysis are compared to those generated by the classical logit and multivariate discriminant analysis, together with more closely related non-parametric decision tree methods. It is concluded that VPRS is a promising addition to existing methods in that it is a practical tool, which generates explicit probabilistic rules from a given information system, with the rules offering the decision maker informative insights into classification problems.  相似文献   
14.
Networks of ambient monitoring stations are used to monitor environmental pollution fields such as those for acid rain and air pollution. Such stations provide regular measurements of pollutant concentrations. The networks are established for a variety of purposes at various times so often several stations measuring different subsets of pollutant concentrations can be found in compact geographical regions. The problem of statistically combining these disparate information sources into a single 'network' then arises. Capitalizing on the efficiencies so achieved can then lead to the secondary problem of extending this network. The subject of this paper is a set of 31 air pollution monitoring stations in southern Ontario. Each of these regularly measures a particular subset of ionic sulphate, sulphite, nitrite and ozone. However, this subset varies from station to station. For example only two stations measure all four. Some measure just one. We describe a Bayesian framework for integrating the measurements of these stations to yield a spatial predictive distribution for unmonitored sites and unmeasured concentrations at existing stations. Furthermore we show how this network can be extended by using an entropy maximization criterion. The methods assume that the multivariate response field being measured has a joint Gaussian distribution conditional on its mean and covariance function. A conjugate prior is used for these parameters, some of its hyperparameters being fitted empirically.  相似文献   
15.
Spatially explicit data pose a series of opportunities and challenges for all the actors involved in providing data for long-term preservation and secondary analysis—the data producer, the data archive, and the data user. We report on opportunities and challenges for each of the three players, and then turn to a summary of current thinking about how best to prepare, archive, disseminate, and make use of social science data that have spatially explicit identification. The core issue that runs through the paper is the risk of the disclosure of the identity of respondents. If we know where they live, where they work, or where they own property, it is possible to find out who they are. Those involved in collecting, archiving, and using data need to be aware of the risks of disclosure and become familiar with best practices to avoid disclosures that will be harmful to respondents.
Myron P. GutmannEmail:
  相似文献   
16.
由于金融业电子化趋势的加快,网络金融犯罪呈上升趋势,深入研究网络金融犯罪已经势在必行。网络技术的发展,使得网络金融犯罪的隐蔽性更强,社会危害性更大。在进行这类案件侦查时,应注重计算机技术与侦查技术相结合,全面收集各种证据,同时要加强地区间的侦查协作,针对网络金融犯罪的特点,灵活使用各种侦查策略。  相似文献   
17.
证券投资意识调查分析 —基于数据挖掘的视角   总被引:1,自引:1,他引:0       下载免费PDF全文
 证券公司对于客户的挖掘和分类有利于挖掘潜在客户和做出适当的营销决策。本文将决策树、逻辑斯蒂回归和贝氏机率分类算法用于判断被访者是否购买股票,以此挖掘潜在客户,用K-means聚类法将股票购买者划分不同的类型,并建议采取不同的服务和营销方式,提高客户的忠诚度。  相似文献   
18.
本文对《中国期刊全文数据库》和《报刊资料索引》中收录的1980—2005年国内美籍华裔文学研究论文从年代分布、期刊分布、作者分布和主题分布等方面进行了统计分析。文章从论文的数量、质量、形式、主题、研究队伍等方面讨论美籍华裔文学研究的发展态势,指出,美籍华裔文学研究从80年代起经历了一个较为缓慢的过程,到本世纪走向成熟。研究者队伍、论文的内容、层次呈多样化,但目前还存在诸多空白需要填补。  相似文献   
19.
Measuring and improving the efficiency of the Chinese commercial banking system has recently attracted increasing interest. Few studies, however, have adopted the two-stage network DEA to explore this issue in the Chinese context. Because the entire operational process of the banking system could be divided into two sub-processes (deposit producing and profit earning), the evaluation of the sub-process efficiencies could be used to assist in identifying the sources of the inefficiency of the entire banking system. In this study, we utilize the network DEA approach to disaggregate, evaluate and test the efficiencies of 16 major Chinese commercial banks during the third round of the Chinese banking reform period (2003–2011) with the variable returns to scale setting and the consideration of undesirable/bad output. The main findings of this study are as follows: (i) the two-stage DEA model is more effective than the conventional black box DEA model in identifying the inefficiency of banking system, and the inefficiency of the Chinese banking system primarily results from the inefficiency of its deposit producing sub-process; (ii) the overall efficiency of the Chinese banking system improves over the study period because of the reform; (iii) the state-owned commercial banks (SOBs) appear to be more overall efficient than the joint-stock commercial banks (JSBs) only in the pre-reform period, and the efficiency difference between the SOBs and the JSBs is reduced over the post-reform period; (iv) the disposal of non-performing loans (NPLs) from the Chinese banking system in general explains its efficiency improvement, and the joint-equity reform of the SOBs specifically increases their efficiencies.  相似文献   
20.
本文首次将Elastic Net这种用于高度相关变量的惩罚方法用于面板数据的贝叶斯分位数回归,并基于非对称Laplace先验分布推导所有参数的后验分布,进而构建Gibbs抽样。为了验证模型的有效性,本文将面板数据的贝叶斯Elastic Net分位数回归方法(BQR. EN)与面板数据的贝叶斯分位数回归方法(BQR)、面板数据的贝叶斯Lasso分位数回归方法(BLQR)、面板数据的贝叶斯自适应Lasso分位数回归方法(BALQR)进行了多种情形下的全方位比较,结果表明BQR. EN方法适用于具有高度相关性、数据维度很高和尖峰厚尾分布特征的数据。进一步地,本文就BQR. EN方法在不同扰动项假设、不同样本量的情形展开模拟比较,验证了新方法的稳健性和小样本特性。最后,本文选取互联网金融类上市公司经济增加值(EVA)作为实证研究对象,检验新方法在实际问题中的参数估计与变量选择能力,实证结果符合预期。  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