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:      
  示例: 沙坡头地区,人工植被区,变化  检索词用空格隔开表示必须包含全部检索词,用“,”隔开表示只需满足任一检索词即可!
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   879篇
  免费   3篇
管理学   202篇
民族学   3篇
人口学   49篇
丛书文集   2篇
理论方法论   73篇
综合类   13篇
社会学   354篇
统计学   186篇
  2024年   20篇
  2023年   7篇
  2022年   4篇
  2021年   13篇
  2020年   29篇
  2019年   45篇
  2018年   54篇
  2017年   41篇
  2016年   43篇
  2015年   25篇
  2014年   39篇
  2013年   110篇
  2012年   52篇
  2011年   42篇
  2010年   29篇
  2009年   29篇
  2008年   47篇
  2007年   31篇
  2006年   24篇
  2005年   29篇
  2004年   29篇
  2003年   21篇
  2002年   22篇
  2001年   15篇
  2000年   12篇
  1999年   12篇
  1998年   3篇
  1997年   7篇
  1996年   5篇
  1995年   5篇
  1994年   2篇
  1993年   5篇
  1992年   1篇
  1991年   1篇
  1990年   3篇
  1988年   3篇
  1987年   2篇
  1986年   2篇
  1985年   3篇
  1984年   5篇
  1983年   3篇
  1980年   1篇
  1979年   1篇
  1974年   3篇
  1972年   2篇
  1969年   1篇
排序方式: 共有882条查询结果,搜索用时 15 毫秒
11.
    
This article reviews the main insights from selected literature on risk perception, particularly in connection with natural hazards. It includes numerous case studies on perception and social behavior dealing with floods, droughts, earthquakes, volcano eruptions, wild fires, and landslides. The review reveals that personal experience of a natural hazard and trust—or lack of trust—in authorities and experts have the most substantial impact on risk perception. Cultural and individual factors such as media coverage, age, gender, education, income, social status, and others do not play such an important role but act as mediators or amplifiers of the main causal connections between experience, trust, perception, and preparedness to take protective actions. When analyzing the factors of experience and trust on risk perception and on the likeliness of individuals to take preparedness action, the review found that a risk perception paradox exists in that it is assumed that high risk perception will lead to personal preparedness and, in the next step, to risk mitigation behavior. However, this is not necessarily true. In fact, the opposite can occur if individuals with high risk perception still choose not to personally prepare themselves in the face of a natural hazard. Therefore, based on the results of the review, this article offers three explanations suggesting why this paradox might occur. These findings have implications for future risk governance and communication as well as for the willingness of individuals to invest in risk preparedness or risk mitigation actions.  相似文献   
12.
    
One of the basic functions of an MRP system is to issue rescheduling messages that urge the planner tospeed up or slow down open orders. It seems in practice that these messages are not used at all by planners. This is mostly due to the inaccuracy of MRP, that more or less ignores safety time, safety stocks and lotsize flexibility in the calculation of reschedule-in messages. Reschedule-out messages are usually ignored because planners do not see the value of the message. Other reasons for not adhering to rescheduling messages are a lack of maintenance of MRP parameters or simply the wrong use of the MRP function. In the future, MRP rescheduling functionality will be used even less than today, due to the changing role of MRP within the planning framework. With the uprise of finite capacity scheduling packages, MRP is being pushed one level upward in the planning hierarchy. This means that rescheduling functionalities for the short term will become completely obsolete in MRP systems.  相似文献   
13.
    
Processes of serially dependent Poisson counts are commonly observed in real-world applications and can often be modeled by the first-order integer-valued autoregressive (INAR) model. For detecting positive shifts in the mean of a Poisson INAR(1) process, we propose the one-sided s exponentially weighted moving average (EWMA) control chart, which is based on a new type of rounding operation. The s-EWMA chart allows computing average run length (ARLs) exactly and efficiently with a Markov chain approach. Using an implementation of this procedure for ARL computation, the s-EWMA chart is easily designed, which is demonstrated with a real-data example. Based on an extensive study of ARLs, the out-of-control performance of the chart is analyzed and compared with that of a c chart and a one-sided cumulative sum (CUSUM) chart. We also investigate the robustness of the chart against departures from the assumed Poisson marginal distribution.  相似文献   
14.
    
Global games of regime change—coordination games of incomplete information in which a status quo is abandoned once a sufficiently large fraction of agents attack it—have been used to study crises phenomena such as currency attacks, bank runs, debt crises, and political change. We extend the static benchmark examined in the literature by allowing agents to take actions in many periods and to learn about the underlying fundamentals over time. We first provide a simple recursive algorithm for the characterization of monotone equilibria. We then show how the interaction of the knowledge that the regime survived past attacks with the arrival of information over time, or with changes in fundamentals, leads to interesting equilibrium properties. First, multiplicity may obtain under the same conditions on exogenous information that guarantee uniqueness in the static benchmark. Second, fundamentals may predict the eventual fate of the regime but not the timing or the number of attacks. Finally, equilibrium dynamics can alternate between phases of tranquility—where no attack is possible—and phases of distress—where a large attack can occur—even without changes in fundamentals.  相似文献   
15.
16.
Although teams benefit from developing plans and processes that boost efficiency and reduce uncertainty, they may become too attached to these plans and escalate commitment when an alternative response is needed. Drawing on theories of team leadership, team processes and escalation of commitment, we propose that a change in leadership can help the team reduce commitment to outdated plans and avoid further escalation over time. Across two studies, we tested and found support for our hypotheses and provide evidence that leadership change can break the cycle of escalation by enhancing leader-driven team reflection and refocusing the team on error correction instead of additional investment. We discuss how the results of these studies extend existing theory and add to our understanding of the important role leaders play in enhancing team adaptation and preventing team escalation.  相似文献   
17.
18.
This paper presents a review of empirical research on the impact of acquisitions on firm performance. The evidence suggests that, in the short run, acquisitions have at best an insignificant impact on shareholder wealth. Long‐run performance analysis reveals overwhelmingly negative returns, while the evidence using accounting performance measures is mixed. The review also examines the impact of bid characteristics on performance. The acquisition of hostile targets, transactions that are paid for with cash and acquisitions of larger targets are associated with superior (or at least less negative) performance, while there is mixed evidence on the benefits of related acquisitions. A number of recent studies find that acquirers with superior pre‐bid performance tend to experience significant underperformance in the post‐bid period.  相似文献   
19.
20.
The GARCH and stochastic volatility (SV) models are two competing, well-known and often used models to explain the volatility of financial series. In this paper, we consider a closed form estimator for a stochastic volatility model and derive its asymptotic properties. We confirm our theoretical results by a simulation study. In addition, we propose a set of simple, strongly consistent decision rules to compare the ability of the GARCH and the SV model to fit the characteristic features observed in high frequency financial data such as high kurtosis and slowly decaying autocorrelation function of the squared observations. These rules are based on a number of moment conditions that is allowed to increase with sample size. We show that our selection procedure leads to choosing the model that fits best, or the simplest model under equivalence, with probability one as the sample size increases. The finite sample size behavior of our procedure is analyzed via simulations. Finally, we provide an application to stocks in the Dow Jones industrial average index.  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