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1.
二元对立现象广泛存在于文学作品之中,二元对立原则也成为一种重要的文学分析方法。运用此原则研究体现二元对立内涵的文学作品,有助于更全面,深入地发掘作品的内涵和艺术精髓。  相似文献   
2.
Longitudinal data often contain missing observations, and it is in general difficult to justify particular missing data mechanisms, whether random or not, that may be hard to distinguish. The authors describe a likelihood‐based approach to estimating both the mean response and association parameters for longitudinal binary data with drop‐outs. They specify marginal and dependence structures as regression models which link the responses to the covariates. They illustrate their approach using a data set from the Waterloo Smoking Prevention Project They also report the results of simulation studies carried out to assess the performance of their technique under various circumstances.  相似文献   
3.
The authors consider the optimal design of sampling schedules for binary sequence data. They propose an approach which allows a variety of goals to be reflected in the utility function by including deterministic sampling cost, a term related to prediction, and if relevant, a term related to learning about a treatment effect To this end, they use a nonparametric probability model relying on a minimal number of assumptions. They show how their assumption of partial exchangeability for the binary sequence of data allows the sampling distribution to be written as a mixture of homogeneous Markov chains of order k. The implementation follows the approach of Quintana & Müller (2004), which uses a Dirichlet process prior for the mixture.  相似文献   
4.
石海军 《东方论坛》2008,(2):1-5,15
全球范围内殖民主义体系的崩溃,使现代性具有了多义性和混乱性。这证明了西方现代性本身存在着矛盾性和含混性,也说明了西方现代性的对立面——反殖民主义和现代性的效颦者——更加深了现代性本身的矛盾性和含混性,表现出对资本主义工业(或后工业)社会所设想的现代文明的质疑与抗议。  相似文献   
5.
The benchmark dose (BMD) is an exposure level that would induce a small risk increase (BMR level) above the background. The BMD approach to deriving a reference dose for risk assessment of noncancer effects is advantageous in that the estimate of BMD is not restricted to experimental doses and utilizes most available dose-response information. To quantify statistical uncertainty of a BMD estimate, we often calculate and report its lower confidence limit (i.e., BMDL), and may even consider it as a more conservative alternative to BMD itself. Computation of BMDL may involve normal confidence limits to BMD in conjunction with the delta method. Therefore, factors, such as small sample size and nonlinearity in model parameters, can affect the performance of the delta method BMDL, and alternative methods are useful. In this article, we propose a bootstrap method to estimate BMDL utilizing a scheme that consists of a resampling of residuals after model fitting and a one-step formula for parameter estimation. We illustrate the method with clustered binary data from developmental toxicity experiments. Our analysis shows that with moderately elevated dose-response data, the distribution of BMD estimator tends to be left-skewed and bootstrap BMDL s are smaller than the delta method BMDL s on average, hence quantifying risk more conservatively. Statistically, the bootstrap BMDL quantifies the uncertainty of the true BMD more honestly than the delta method BMDL as its coverage probability is closer to the nominal level than that of delta method BMDL. We find that BMD and BMDL estimates are generally insensitive to model choices provided that the models fit the data comparably well near the region of BMD. Our analysis also suggests that, in the presence of a significant and moderately strong dose-response relationship, the developmental toxicity experiments under the standard protocol support dose-response assessment at 5% BMR for BMD and 95% confidence level for BMDL.  相似文献   
6.
基于二相编码雷达对大压缩比信号的要求,提出了一种比直接算法平均提高效率0.5P(P 为序列长度)的快速数字优化方法。作为这种快速算法的实际应用,还对 P=255的二相编码脉冲压缩信号进行了优化。  相似文献   
7.
从收支项目看秦汉二元财政的源流   总被引:1,自引:0,他引:1  
史卫 《南都学坛》2005,25(2):9-14
汉代财政分为国家财政和帝室财政,由大司农和少府分掌,为大家所熟知。但对二元财政的来源却少有辨析,一般承袭郑玄关于大司农是太府继承的说法。实际上少府和太府在收支项目上都比较接近,有着明显的继承关系,而大司农则是由负责主持策命诸侯及保管爵禄文书的内史演变而来。在国家职能转轨过程中,内史发展成为管理国家财政及畿内地区事务的机构,最后进一步分离出专门管理国家财政的治粟内史。二元财政体制的设计来源于收支对应的原始财政平衡思想。  相似文献   
8.
A fast splitting procedure for classification trees   总被引:1,自引:0,他引:1  
This paper provides a faster method to find the best split at each node when using the CART methodology. The predictability index is proposed as a splitting rule for growing the same classification tree as CART does when using the Gini index of heterogeneity as an impurity measure. A theorem is introduced to show a new property of the index : the for a given predictor has a value not lower than the for any split generated by the predictor. This property is used to make a substantial saving in the time required to generate a classification tree. Three simulation studies are presented in order to show the computational gain in terms of both the number of splits analysed at each node and the CPU time. The proposed splitting algorithm can prove computational efficiency in real data sets as shown in an example.  相似文献   
9.
基于二元关系的产业关联分析方法研究   总被引:2,自引:0,他引:2  
本文运用二元关系理论和Warshall算法计算产业系统中各产业之间的连通关联关系,为认识产业结构和产业关联状况提供了简便的量化分析方法。结合安徽产业系统的实例,分析了安徽产业结构的特点及产业关联状况。  相似文献   
10.
With the rapid development of modern sensor technology, high-dimensional data streams appear frequently nowadays, bringing urgent needs for effective statistical process control (SPC) tools. In such a context, the online monitoring problem of high-dimensional and correlated binary data streams is becoming very important. Conventional SPC methods for monitoring multivariate binary processes may fail when facing high-dimensional applications due to high computational complexity and the lack of efficiency. In this paper, motivated by an application in extreme weather surveillance, we propose a novel pairwise approach that considers the most informative pairwise correlation between any two data streams. The information is then integrated into an exponential weighted moving average (EWMA) charting scheme to monitor abnormal mean changes in high-dimensional binary data streams. Extensive simulation study together with a real-data analysis demonstrates the efficiency and applicability of the proposed control chart.  相似文献   
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