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   2728篇
  免费   160篇
  国内免费   64篇
管理学   917篇
民族学   2篇
人口学   28篇
丛书文集   100篇
理论方法论   170篇
综合类   1025篇
社会学   219篇
统计学   491篇
  2024年   3篇
  2023年   29篇
  2022年   29篇
  2021年   53篇
  2020年   69篇
  2019年   84篇
  2018年   74篇
  2017年   101篇
  2016年   102篇
  2015年   110篇
  2014年   132篇
  2013年   326篇
  2012年   158篇
  2011年   140篇
  2010年   100篇
  2009年   124篇
  2008年   134篇
  2007年   130篇
  2006年   148篇
  2005年   161篇
  2004年   115篇
  2003年   86篇
  2002年   98篇
  2001年   80篇
  2000年   61篇
  1999年   48篇
  1998年   34篇
  1997年   31篇
  1996年   26篇
  1995年   21篇
  1994年   19篇
  1993年   25篇
  1992年   14篇
  1991年   16篇
  1990年   15篇
  1989年   9篇
  1988年   16篇
  1987年   2篇
  1986年   3篇
  1985年   7篇
  1984年   7篇
  1983年   5篇
  1981年   4篇
  1979年   1篇
  1978年   1篇
  1977年   1篇
排序方式: 共有2952条查询结果,搜索用时 78 毫秒
31.
We compare husbands' and wives' views of the wantedness of their most recent pregnancy in the Philippines, a country where relatively high levels of unintended fertility persist. This research is an extension of earlier work that looked separately at individual men's and women's responses. We analyze survey data for 369 couples and find that those most at risk of experiencing a pregnancy that neither spouse wanted tended to be higher parity couples, those who were more fatalistic, those who were practicing Catholics who attended religious services frequently, and those among whom the husband was the sole breadwinner. Higher parity women and older women were also more apt to experience a pregnancy that was wanted by only 1 spouse. Women who had difficulty discussing sexual matters with their husbands were more likely than other women to have a pregnancy that their husbands wanted but they did not.  相似文献   
32.
To explore the projection efficiency of a design, Tsai, et al [2000. Projective three-level main effects designs robust to model uncertainty. Biometrika 87, 467–475] introduced the Q criterion to compare three-level main-effects designs for quantitative factors that allow the consideration of interactions in addition to main effects. In this paper, we extend their method and focus on the case in which experimenters have some prior knowledge, in advance of running the experiment, about the probabilities of effects being non-negligible. A criterion which incorporates experimenters’ prior beliefs about the importance of each effect is introduced to compare orthogonal, or nearly orthogonal, main effects designs with robustness to interactions as a secondary consideration. We show that this criterion, exploiting prior information about model uncertainty, can lead to more appropriate designs reflecting experimenters’ prior beliefs.  相似文献   
33.
The elimination or knockout format is one of the most common designs for pairing competitors in tournaments and leagues. In each round of a knockout tournament, the losers are eliminated while the winners advance to the next round. Typically, the goal of such a design is to identify the overall best player. Using a common probability model for expressing relative player strengths, we develop an adaptive approach to pairing players each round in which the probability that the best player advances to the next round is maximized. We evaluate our method using simulated game outcomes under several data-generating mechanisms, and compare it to random pairings, to the standard knockout format, and to two variants of the standard format.  相似文献   
34.
To ascertain the viability of a project, undertake resource allocation, take part in bidding processes, and other related decisions, modern project management requires forecasting techniques for cost, duration, and performance of a project, not only under normal circumstances, but also under external events that might abruptly change the status quo. We provide a Bayesian framework that provides a global forecast of a project's performance. We aim at predicting the probabilities and impacts of a set of potential scenarios caused by combinations of disruptive events, and using this information to deal with project management issues. To introduce the methodology, we focus on a project's cost, but the ideas equally apply to project duration or performance forecasting. We illustrate our approach with an example based on a real case study involving estimation of the uncertainty in project cost while bidding for a contract.  相似文献   
35.
阐释了国有控股公司治理出现的新变化以及给企业党组织带来的新情况,重点分析了国有控股公司党组织参与决策不仅是必要的而且是可行的,同时指出公司党组织参与决策的不适应之处还需要进一步探索研究。  相似文献   
36.
借助潜在需求这一概念提出决策分析框架,帮助决策者在决策制定的最初分析阶段排除那些与本企业环境和供应链条件不相容的电子商务模式;旨在为电子商务从业者和研究人员提供一个实施电子商务模式决策分析时的支持模型.  相似文献   
37.
To inform local and regional decisions about protecting short-term and long-term quality of life, the Consortium for Atlantic Regional Assessment (CARA) provides data and tools (for the northeastern United States) that can help decision makers understand how outcomes of their decisions could be affected by potential changes in both climate and land use. On an interactive, user-friendly website, CARA has amassed data on climate (historical records and future projections for seven global climate models), land cover, and socioeconomic and environmental variables, along with tools to help decision makers tailor the data for their own decision types and locations. CARA Advisory Council stakeholders help identify what information and tools stakeholders would find most useful and how to present these; they also provide in-depth feedback for subregion case studies. General lessons include: (1) decision makers want detailed local projections for periods short enough to account for extreme events, in contrast to the broader spatial and temporal observations and projections that are available or consistent at a regional level; (2) stakeholders will not use such a website unless it is visually appealing and easy to find the information they want; (3) some stakeholders need background while others want to go immediately to data, and some want maps while others want text or tables. This article also compares what has been learned across case studies of Cape May County, New Jersey, Cape Cod, Massachusetts, and Hampton Roads, Virginia, relating specifically to sea-level rise. Lessons include: (1) groups can be affected differently by physical dangers compared with economic dangers; (2) decisions will differ according to decision makers' preferences about waiting and risk tolerance; (3) future scenarios and maps can help assess the impacts of dangers to emergency evacuation routes, homes, and infrastructure, and the natural environment; (4) residents' and decision makers' perceptions are affected by information about potential local impacts from global climate change.  相似文献   
38.
最佳套期保值比率(OHR)的估计方法一直是金融工程理论研究的核心问题,从最开始的幼稚法到JSE法 以及随后的很多其他改进方法,保值效率都有不同程度的提高。使用包含误差修正结构的GARCH模型估计外汇 (澳大利亚元)期货的套期保值比率。通过效率比较,证实该模型所得到的套期保值比率比起传统方法都具有更好 的降低风险能力。  相似文献   
39.
Summary This paper solves some D-optimal design problems for certain Generalized Linear Models where the mean depends on two parameters and two explanatory variables. In all of the cases considered the support point of the optimal designs are found to be independent of the unknown parameters. While in some cases the optimal design measures are given by two points with equal weights, in others the support is given by three point with weights depending on the unknown parameters, hence the designs are locally optimal in general. Empirical results on the efficiency of the locally optimal designs are also given. Some of the designs found can also be used for planning D-optimal experiments for the normal linear model, where the mean must be positive. This research was carried out in part at University College, London as an M.Sc. project. Thanks are due to Prof. I. Ford (University of Glasgow) and Prof. A. Giovagnoli (University of Perugia) for their valuable suggestions and critical observations.  相似文献   
40.
With the increasing pressure on social and health care resources,professionals have to be more explicit in their decision makingregarding the long-term care of older people. This groundedtheory study used 19 focus groups and nine semi-structured interviews(99 staff in total) to explore professional perspectives onthis decision making. Focus group participants and intervieweescomprised care managers, social workers, consultant geriatricians,general medical practitioners, community nurses, home care managers,occupational therapists and hospital discharge support staff.The emerging themes spanned context, clients, families and services.Decisions were often prompted by a crisis, hindering professionalsseeking to make a measured assessment. Fear of burglary andassault, and the willingness and availability of family to helpwere major factors in decisions about living at home. Serviceavailability in terms of public funding for community care,the availability of home care workers and workload pressureson primary care services influenced decision ‘thresholds’regarding admission to institutional care. Assessment toolsdesigned to assist decision making about the long-term careof older people need to take into account the critical aspectsof individual fears and motivation, family support and the availabilityof publicly funded services as well as functional and medicalneeds.  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