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   1012篇
  免费   9篇
管理学   20篇
人口学   3篇
丛书文集   14篇
理论方法论   9篇
综合类   69篇
社会学   13篇
统计学   893篇
  2023年   1篇
  2021年   1篇
  2020年   7篇
  2019年   20篇
  2018年   25篇
  2017年   44篇
  2016年   22篇
  2015年   22篇
  2014年   21篇
  2013年   413篇
  2012年   108篇
  2011年   23篇
  2010年   18篇
  2009年   18篇
  2008年   25篇
  2007年   26篇
  2006年   16篇
  2005年   17篇
  2004年   20篇
  2003年   21篇
  2002年   17篇
  2001年   25篇
  2000年   13篇
  1999年   8篇
  1998年   11篇
  1997年   11篇
  1996年   6篇
  1995年   7篇
  1994年   9篇
  1993年   3篇
  1992年   3篇
  1991年   1篇
  1990年   5篇
  1989年   4篇
  1988年   2篇
  1987年   1篇
  1986年   1篇
  1985年   2篇
  1984年   5篇
  1983年   7篇
  1982年   4篇
  1980年   2篇
  1979年   2篇
  1978年   1篇
  1977年   2篇
  1975年   1篇
排序方式: 共有1021条查询结果,搜索用时 15 毫秒
51.
Very often in regression analysis, a particular functional form connecting known covariates and unknown parameters is either suggested by previous work or demanded by theoretical considerations so that the deterministic part of the responses has a known form. However, the underlying error structure is often less well understood. In this case, the transform-both-sides (TBS) models are appropriate. In this paper we generalize the usual TBS models and develop tests to assess goodness of fit when fitting TBS or GTBS models. Parameter estimation is discussed, and tests based on the Cramér-von Mises statistic and the Anderson-Darling statistic are presented with a table suitable for finite-sample applications.  相似文献   
52.
介绍了英语成绩进展考试的定义;分析了成绩进展考试的重要性以及在应用中可能会出现的问题.  相似文献   
53.
Summary.  Functional magnetic resonance imaging (FMRI) measures the physiological response of the human brain to experimentally controlled stimulation. In a periodically designed experiment it is of interest to test for a difference in the timing (phase shift) of the response between two anatomically distinct brain regions. We suggest two tests for an interregional difference in phase shift: one based on asymptotic theory and one based on bootstrapping. Whilst the two procedures differ in some of their assumptions, both tests rely on employing the large number of voxels (three-dimensional pixels) in non-activated brain regions to take account of spatial autocorrelation between voxelwise phase shift observations within the activated regions of interest. As an example we apply both tests, and their counterparts assuming spatial independence, to FMRI phase shift data that were acquired from a normal young woman during performance of a periodically designed covert verbal fluency task. We conclude that it is necessary to take account of spatial autocovariance between voxelwise FMRI time series parameter estimates such as the phase shift, and that the most promising way of achieving this is by modelling the spatial autocorrelation structure from a suitably defined base region of the image slice.  相似文献   
54.
This paper considers the problem of an acceptance sampling plan for a truncated life test when the lifetime follows the generalized Rayleigh distribution. For different acceptance numbers, confidence levels, and values of the ratio of the fixed experiment time to the specified mean life, the minimum sample sizes necessary to ensure the specified mean life are found. The operating characteristic values of the sampling plans and producer's risk are discussed. Some tables are presented and the use of the tables is illustrated by a numerical example.  相似文献   
55.
Abstract.  We present a new approach to handle dependencies within the general framework of case–control designs, illustrating our approach by a particular application from the field of genetic epidemiology. The method is derived for parent–offspring trios, which will later be relaxed to more general family structures. For applications in genetic epidemiology we consider tests on equality of allele frequencies among cases and controls utilizing well-known risk measures to test for independence of phenotype and genotype at the observed locus. These test statistics are derived as functions of the entries in the associated contingency table containing the numbers of the alleles under consideration in the case and the control group. We find the joint asymptotic distribution of these entries, which enables us to derive critical values for any test constructed on this basis. A simulation study reveals the finite sample behaviour of our test statistics.  相似文献   
56.
Use of a suitable stopping rule yields exact uniformly most powerful tests and minimum variance unbiased estimators of various parameters of a Markov branching model with or without immigration. The population model discussed includes the pure birth, simple epidemic, immigration-death, M/M/ 1 queue, linear birth-death and a branching diffusion process, among others, as special cases.  相似文献   
57.
For testing the hypothesis that several (s?2) linear regression surfaces Xki=αk+βkcki+Zki (k=1,…,s) are parallel to one another, i.e., β1=?=βs, a class of rank-order tests are considered. The tests are shown to be asymptotically distribution-free, and their asymptotic efficiency relative to the general likelihood ratio test is derived. Asymptotic optimality in the sense of Wald is also discussed.  相似文献   
58.
A class of tests is proposed for testing H0 F?(x) = e?λx, λ > 0, x≥0 vs. H1 F?(x + y) ≤ F?(x)F?(y), x, y≥0, with strict inequality for some x, y ≥ 0 (F = new is better than used). Efficiency comparisons of some tests within the class are made and a new test is proposed on the basis of these comparisons. Consistency and the asymptotic normality of the class of tests is proved under fairly broad conditions on the underlying entities.  相似文献   
59.
本文设计并实现了利用电力载波传输温度数据的温度采集系统。本文以LM1893电力线载波芯片作为基础,以Mega128为控制核心,设计了区域的硬件接口电路,实现了区域的温度采集和显示。在温度数据通过调制电路耦合到电力线中上传到接收端时,数据解调传给上位机,并将数据导入数据库,实现了数据的集中管理。  相似文献   
60.
Nonlinear regression models arise when definite information is available about the form of the relationship between the response and predictor variables. Such information might involve direct knowledge of the actual form of the true model or might be represented by a set of differential equations that the model must satisfy. We develop M-procedures for estimating parameters and testing hypotheses of interest about these parameters in nonlinear regression models for repeated measurement data. Under regularity conditions, the asymptotic properties of the M-procedures are presented, including the uniform linearity, normality and consistency. The computation of the M-estimators of the model parameters is performed with iterative procedures, similar to Newton–Raphson and Fisher's scoring methods. The methodology is illustrated by using a multivariate logistic regression model with real data, along with a simulation study.  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