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   1248篇
  免费   31篇
  国内免费   17篇
管理学   186篇
劳动科学   1篇
人口学   19篇
丛书文集   38篇
理论方法论   190篇
综合类   301篇
社会学   29篇
统计学   532篇
  2023年   4篇
  2022年   6篇
  2021年   11篇
  2020年   15篇
  2019年   30篇
  2018年   36篇
  2017年   39篇
  2016年   21篇
  2015年   29篇
  2014年   55篇
  2013年   230篇
  2012年   73篇
  2011年   48篇
  2010年   41篇
  2009年   43篇
  2008年   63篇
  2007年   71篇
  2006年   65篇
  2005年   59篇
  2004年   37篇
  2003年   38篇
  2002年   37篇
  2001年   43篇
  2000年   24篇
  1999年   29篇
  1998年   13篇
  1997年   12篇
  1996年   11篇
  1995年   12篇
  1994年   8篇
  1993年   15篇
  1992年   9篇
  1991年   8篇
  1990年   9篇
  1989年   13篇
  1988年   12篇
  1987年   3篇
  1986年   1篇
  1985年   2篇
  1984年   3篇
  1983年   3篇
  1982年   3篇
  1981年   1篇
  1980年   1篇
  1979年   3篇
  1978年   5篇
  1977年   1篇
  1975年   1篇
排序方式: 共有1296条查询结果,搜索用时 140 毫秒
21.
考虑质量失误的供应链博弈模型研究   总被引:4,自引:0,他引:4  
在理性的制造商和供应商组成的二级供应链中,考虑存在产品质量失误的情况下,通过最优化方法选择中间品的质量水平和制造商的检测水平,以实现供应链的利润最大化.并结合实际情况,根据质量内部、外部失误的不同承担方式,讨论了三种质量损失承担方式,得到在整体损失由两者共同承担的情况下,通过制定合理的内、外部损失分配系数,可以使两者选择水平的纳什均衡解与供应链的全局最优解相符,从而实现供应链全局最优和局部最优的一致.所得结论对指导供应链的有效运作有着较好的实际意义和参考价值.  相似文献   
22.
基于质量信息不对称度的消费者效用与企业利润研究   总被引:1,自引:0,他引:1  
本文回顾并分析了国内外学者关于质量信息不对称以及质量信息不对称度的相关研究成果,通过比较产品质量真实信息与消费者预期质量信息对质量信息不对称度进行了定义.创造性地将质量信息不对称度引入消费者效用和企业利润的研究之中,基于质量信息不对称度、产品质量与产品价格构建了消费者效用模型与企业利润模型,讨论了质量信息不对称度变化对消费者效用与企业利润的影响,分析了质量信息不对称度和消费者偏好变化的经济意义,实例研究验证了本文定义及推理的合理性和有效性.获得了有意义的结论:企业可以通过调整发布的信息量来改变质量信息不对称度追求较大的利润,将产品质量信息不对称度控制在合适的水平才能获得较高的企业利润和消费者效用.  相似文献   
23.
从现在到2020年是打赢脱贫攻坚战的关键时期,从农民自身角度研究搬迁意愿,对加快实施易地扶贫移民搬迁具有重要意义。研究依据西方微观人口迁移理论:地方效用理论、计划行为理论和效价[CD*2]期望理论,整合构建了中国国情下由政府引导的易地扶贫搬迁意愿的理论分析框架。以陕南移民搬迁为例,在验证性因子分析的基础上,运用有序Logit模型和最优尺度模型对理论假设进行检验。结果显示:①心理因素、政策和预期因素、环境因素对搬迁意愿具有显著影响 ②控制变量中家庭人口数、非农劳动力比例、家庭成员求学婚姻等控制变量与搬迁意愿显著相关;③没有搬迁的主要的顾虑是搬迁后找不到工作、城镇生活成本高、搬迁成本高、搬迁后的适应等问题。研究建议政府部门在搬迁补助、就业安置、搬迁后适应等方面加大支持力度,增强搬迁的信心。  相似文献   
24.
The components of a reliability system subjected to a common random environment usually have dependent lifetimes. This paper studies the stochastic properties of such a system with lifetimes of the components following multivariate frailty models and multivariate mixed proportional reversed hazard rate (PRHR) models, respectively. Through doing stochastic comparison, we devote to throwing a new light on how the random environment affects the number of working components of a reliability system and on assessing the performance of a k-out-of-n system.  相似文献   
25.
In many industrial quality control experiments and destructive stress testing, the only available data are successive minima (or maxima)i.e., record-breaking data. There are two sampling schemes used to collect record-breaking data: random sampling and inverse sampling. For random sampling, the total sample size is predetermined and the number of records is a random variable while in inverse-sampling the number of records to be observed is predetermined; thus the sample size is a random variable. The purpose of this papper is to determinevia simulations, which of the two schemes, if any, is more efficient. Since the two schemes are equivalent asymptotically, the simulations were carried out for small to moderate sized record-breaking samples. Simulated biases and mean square errors of the maximum likelihood estimators of the parameters using the two sampling schemes were compared. In general, it was found that if the estimators were well behaved, then there was no significant difference between the mean square errors of the estimates for the two schemes. However, for certain distributions described by both a shape and a scale parameter, random sampling led to estimators that were inconsistent. On the other hand, the estimated obtained from inverse sampling were always consistent. Moreover, for moderated sized record-breaking samples, the total sample size that needs to be observed is smaller for inverse sampling than for random sampling.  相似文献   
26.

In this article, the validity of procedures for testing the significance of the slope in quantitative linear models with one explanatory variable and first-order autoregressive [AR(1)] errors is analyzed in a Monte Carlo study conducted in the time domain. Two cases are considered for the regressor: fixed and trended versus random and AR(1). In addition to the classical t -test using the Ordinary Least Squares (OLS) estimator of the slope and its standard error, we consider seven t -tests with n-2\,\hbox{df} built on the Generalized Least Squares (GLS) estimator or an estimated GLS estimator, three variants of the classical t -test with different variances of the OLS estimator, two asymptotic tests built on the Maximum Likelihood (ML) estimator, the F -test for fixed effects based on the Restricted Maximum Likelihood (REML) estimator in the mixed-model approach, two t -tests with n - 2 df based on first differences (FD) and first-difference ratios (FDR), and four modified t -tests using various corrections of the number of degrees of freedom. The FDR t -test, the REML F -test and the modified t -test using Dutilleul's effective sample size are the most valid among the testing procedures that do not assume the complete knowledge of the covariance matrix of the errors. However, modified t -tests are not applicable and the FDR t -test suffers from a lack of power when the regressor is fixed and trended ( i.e. , FDR is the same as FD in this case when observations are equally spaced), whereas the REML algorithm fails to converge at small sample sizes. The classical t -test is valid when the regressor is fixed and trended and autocorrelation among errors is predominantly negative, and when the regressor is random and AR(1), like the errors, and autocorrelation is moderately negative or positive. We discuss the results graphically, in terms of the circularity condition defined in repeated measures ANOVA and of the effective sample size used in correlation analysis with autocorrelated sample data. An example with environmental data is presented.  相似文献   
27.
Louis Anthony Cox  Jr. 《Risk analysis》2012,32(11):1919-1934
Extreme and catastrophic events pose challenges for normative models of risk management decision making. They invite development of new methods and principles to complement existing normative decision and risk analysis. Because such events are rare, it is difficult to learn about them from experience. They can prompt both too little concern before the fact, and too much after. Emotionally charged and vivid outcomes promote probability neglect and distort risk perceptions. Aversion to acting on uncertain probabilities saps precautionary action; moral hazard distorts incentives to take care; imperfect learning and social adaptation (e.g., herd‐following, group‐think) complicate forecasting and coordination of individual behaviors and undermine prediction, preparation, and insurance of catastrophic events. Such difficulties raise substantial challenges for normative decision theories prescribing how catastrophe risks should be managed. This article summarizes challenges for catastrophic hazards with uncertain or unpredictable frequencies and severities, hard‐to‐envision and incompletely described decision alternatives and consequences, and individual responses that influence each other. Conceptual models and examples clarify where and why new methods are needed to complement traditional normative decision theories for individuals and groups. For example, prospective and retrospective preferences for risk management alternatives may conflict; procedures for combining individual beliefs or preferences can produce collective decisions that no one favors; and individual choices or behaviors in preparing for possible disasters may have no equilibrium. Recent ideas for building “disaster‐resilient” communities can complement traditional normative decision theories, helping to meet the practical need for better ways to manage risks of extreme and catastrophic events.  相似文献   
28.
随着网络视频运营商收费节目试看的兴起,而节目试看对网络视频运营商诸如市场规模,利润等市场策略的影响所知甚少。本文在考虑网络用户情绪效用情况下,通过构建高质量视频运营商首播节目与后来跟进的低质量视频运营商播出该节目的博弈模型,研究高质量视频运营商首播节目之前提供节目试看对两个运营商收费模式下的节目最优收费价格和免费模式下的最优嵌入广告量以及视频节目提供模式选择的影响。研究表明,高质量视频运营商在节目首播之前提供节目充分试看能够实现节目最优收费价格最高,利润最大,因此节目充分试看是其最优策略;并且低质量运营商在其单位广告收益与用户单位广告"成本"满足一定条件下,高质量运营商提供的节目的充分试看能够减少低质量运营商总利润,因此避免低质量视频运营商搭乘节目试看的顺风车;高质量视频运营商提供节目充分试看情况下,高质量视频运营商只采取收费模式为其最优市场策略,低质量视频运营商采取免费模式为其最优市场策略。本文的研究成果对网络视频运营商日常运营有一定的管理学启示与应用价值。  相似文献   
29.
生鲜供应链整体生鲜度的提升对减少浪费、提高供应链整体盈利水平及社会福利有重要意义。本文基于消费者效用理论研究了两供应商和单一零售商组成的供应链系统,构建了单周期下生鲜农产品生鲜度激励模型,模型以供应商为领导者,采用Stackelberg博弈方法求解得到了均衡状态下供应商、零售商的最优定价策略及供应商新鲜度努力选择。研究结果表明,供应商和零售商利润与消费者价格敏感系数呈反向变化,与新鲜度敏感系数呈同向变化。在价格竞争市场,供应商保鲜努力程度和利润与价格替代率呈反向变化;在生鲜度竞争市场,供应商保鲜努力程度和利润与新鲜度替代率呈同向变化。基于研究结论,厂商及政府应当联手引导消费者的消费观念,尽可能减少由于信息不对称引致的道德风险,在市场价格替代率不变甚至降低的情形下,提高生鲜度替代率,使得消费者的意愿支付价格上升,提高自身讨价还价能力,获取更多利润。  相似文献   
30.
This article examines how young Filipino men looking to work in international seafaring deploy servitude as a means of attaining education-to-work transition. It focuses on those applying to work for free as ‘utility men’ (gofer or flunkey) in Manila’s manning and crewing agencies that supply seafarers to ship operators around the world in exchange for the promise of boarding a ship. Based on participant observation and life history interviews, the article accounts for how they transform their servitude into diskarte – strategy by which they navigate the limited employment opportunities in the Philippines – by constructing their ‘utility manning’ as an informal and negotiated pathway to employment. The young Filipino men’s seeking and enduring servitude, geared towards gleaning better social possibilities, becomes a profoundly rational act of investing in and securing their future.  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