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   2896篇
  免费   88篇
  国内免费   43篇
管理学   503篇
民族学   4篇
人口学   6篇
丛书文集   113篇
理论方法论   20篇
综合类   1131篇
社会学   35篇
统计学   1215篇
  2024年   7篇
  2023年   21篇
  2022年   48篇
  2021年   32篇
  2020年   51篇
  2019年   77篇
  2018年   82篇
  2017年   138篇
  2016年   94篇
  2015年   84篇
  2014年   98篇
  2013年   361篇
  2012年   196篇
  2011年   148篇
  2010年   137篇
  2009年   116篇
  2008年   143篇
  2007年   165篇
  2006年   148篇
  2005年   138篇
  2004年   126篇
  2003年   100篇
  2002年   85篇
  2001年   72篇
  2000年   83篇
  1999年   53篇
  1998年   39篇
  1997年   37篇
  1996年   30篇
  1995年   22篇
  1994年   19篇
  1993年   12篇
  1992年   21篇
  1991年   9篇
  1990年   7篇
  1989年   13篇
  1988年   6篇
  1987年   3篇
  1985年   2篇
  1984年   1篇
  1981年   2篇
  1975年   1篇
排序方式: 共有3027条查询结果,搜索用时 843 毫秒
91.
Since multi-attribute control charts have received little attention compared with multivariate variable control charts, this research is concerned with developing a new methodology to employ the multivariate exponentially weighted moving average (MEWMA) charts for m-attribute binomial processes; the attributes being the number of nonconforming items. Moreover, since the variable sample size and sampling interval (VSSI) MEWMA charts detect small process mean shifts faster than the traditional MEWMA, an economic design of the VSSI MEWMA chart is proposed to obtain the optimum design parameters of the chart. The sample size, the sampling interval, and the warning/action limit coefficients are obtained using a genetic algorithm such that the expected total cost per hour is minimized. At the end, a sensitivity analysis has been carried out to investigate the effects of the cost and the model parameters on the solution of the economic design of the VSSI MEWMA chart.  相似文献   
92.
为了做好专业技术岗位聘用工作,高校应该认真研究普遍存在的“双肩挑”人员的管理现状和探索新的使用方法。笔者对高校中“双肩挑”管理模式现行管理政策与措施进行了调查和研究,提出了应加强对“双肩挑”岗位设置的管理,同时,应注重管理队伍朝着专职和专业的方向发展,并在高校中逐步提高学术权力的领导地位、建立新时期高校管理体制的新格局和确保高校人事管理科学发展的建议。  相似文献   
93.
This study considers a typical scheduling environment that is influenced by the behavioral phenomenon of multitasking. Under multitasking, the processing of a selected job suffers from interruption by other jobs that are available but unfinished. This situation arises in a wide variety of applications; for example, administration, manufacturing, and process and project management. Several classical solution methods for scheduling problems no longer apply in the presence of multitasking. The solvability of any scheduling problem under multitasking is no easier than that of the corresponding classical problem. We develop optimal algorithms for some fundamental and practical single machine scheduling problems with multitasking. For other problems, we show that they are computationally intractable, even though in some cases the corresponding problem in classical scheduling is efficiently solvable. We also study the cost increase and value gained due to multitasking. This analysis informs companies about how much it would be worthwhile to invest in measures to reduce or encourage multitasking.  相似文献   
94.
Software packages usually report the results of statistical tests using p-values. Users often interpret these values by comparing them with standard thresholds, for example, 0.1, 1, and 5%, which is sometimes reinforced by a star rating (***, **, and *, respectively). We consider an arbitrary statistical test whose p-value p is not available explicitly, but can be approximated by Monte Carlo samples, for example, by bootstrap or permutation tests. The standard implementation of such tests usually draws a fixed number of samples to approximate p. However, the probability that the exact and the approximated p-value lie on different sides of a threshold (the resampling risk) can be high, particularly for p-values close to a threshold. We present a method to overcome this. We consider a finite set of user-specified intervals that cover [0, 1] and that can be overlapping. We call these p-value buckets. We present algorithms that, with arbitrarily high probability, return a p-value bucket containing p. We prove that for both a bounded resampling risk and a finite runtime, overlapping buckets need to be employed, and that our methods both bound the resampling risk and guarantee a finite runtime for such overlapping buckets. To interpret decisions with overlapping buckets, we propose an extension of the star rating system. We demonstrate that our methods are suitable for use in standard software, including for low p-value thresholds occurring in multiple testing settings, and that they can be computationally more efficient than standard implementations.  相似文献   
95.
Abstract

In this article, we propose a penalized local log-likelihood method to locally select the number of components in non parametric finite mixture of regression models via proportion shrinkage method. Mean functions and variance functions are estimated simultaneously. We show that the number of components can be estimated consistently, and further establish asymptotic normality of functional estimates. We use a modified EM algorithm to estimate the unknown functions. Simulations are conducted to demonstrate the performance of the proposed method. We illustrate our method via an empirical analysis of the housing price index data of United States.  相似文献   
96.
股利分配政策是上市公司对盈利进行分配或留存的决策问题.在大数据时代运用微软商业智能中的决策树算法,可以对农业上市公司的相关财务数据进行深入挖掘.通过决策树规则进行分析,找出农业上市公司股利分配采购影响因素,为农业上市公司制定现金股利分配股利分配政策提供决策依据,也为商业智能工具在企业决策中的运用提供借鉴.  相似文献   
97.
针对分水岭算法存在的过分割问题以及泡罩包装药品图像的特点,提出一种改进的分水岭分割算法对泡罩包装的药品进行分割。该方法将形态学重建运算与使用控制标记符的方法相结合,首先对原图像进行开闭重建,根据邻域像素连通性提取重建后图像的局部极大值作为标记,从而抑制其他的局部极小值,然后依据标记对原始的梯度图像进行修正,最后对修改后的梯度图像进行分水岭分割。试验表明,该方法在缺陷药品检测中,可以有效的抑制传统分水岭的过分割,分割效果良好。  相似文献   
98.
针对传统基于继电器控制的稳压电源在带负载工作时,档位切换常常伴随火弧现象的问题,设计了一种可广泛 应用于此类稳压电源上的自适应去火弧技术:使用光耦和多级运放完成对零点和电压电流的采样;基于单片机的10量, 实现对继电器的驱动和控制;基于RCC自激震荡原理为系统提供稳定电源;设计了稳压器的完整软件系统程序,并在软 件中应用自适应去火弧算法。实验结果表明:自适应去火弧技术,能够有效地规避火弧现象的产生,并能够根据条件作 出调整。采用自适应去火弧技术的稳压系统达到了设计目标,延长了系统工作寿命。  相似文献   
99.
Subgroup detection has received increasing attention recently in different fields such as clinical trials, public management and market segmentation analysis. In these fields, people often face time‐to‐event data, which are commonly subject to right censoring. This paper proposes a semiparametric Logistic‐Cox mixture model for subgroup analysis when the interested outcome is event time with right censoring. The proposed method mainly consists of a likelihood ratio‐based testing procedure for testing the existence of subgroups. The expectation–maximization iteration is applied to improve the testing power, and a model‐based bootstrap approach is developed to implement the testing procedure. When there exist subgroups, one can also use the proposed model to estimate the subgroup effect and construct predictive scores for the subgroup membership. The large sample properties of the proposed method are studied. The finite sample performance of the proposed method is assessed by simulation studies. A real data example is also provided for illustration.  相似文献   
100.
This article reviews symmetrical global sensitivity analysis based on the analysis of variance of high-dimensional model representation. To overcome the computational difficulties and explore the use of symmetrical design of experiment (SDOE), two methods are presented. If the form of the objective function f is known, we use SDOE to estimate the symmetrical global sensitivity indices instead of Monte Carlo or quasi-Monte Carlo simulation. Otherwise, we use the observed values of the experiment to do symmetrical global sensitivity analysis. These methods are easy to implement and can reduce the computational cost. An example is given by symmetrical design of experiment.  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