全文获取类型
收费全文 | 64769篇 |
免费 | 1907篇 |
国内免费 | 765篇 |
专业分类
管理学 | 2065篇 |
劳动科学 | 20篇 |
民族学 | 928篇 |
人才学 | 13篇 |
人口学 | 743篇 |
丛书文集 | 8168篇 |
理论方法论 | 2559篇 |
综合类 | 47641篇 |
社会学 | 3392篇 |
统计学 | 1912篇 |
出版年
2024年 | 127篇 |
2023年 | 406篇 |
2022年 | 537篇 |
2021年 | 682篇 |
2020年 | 856篇 |
2019年 | 852篇 |
2018年 | 808篇 |
2017年 | 961篇 |
2016年 | 1049篇 |
2015年 | 1339篇 |
2014年 | 3249篇 |
2013年 | 4059篇 |
2012年 | 4088篇 |
2011年 | 4758篇 |
2010年 | 3813篇 |
2009年 | 3903篇 |
2008年 | 4052篇 |
2007年 | 4842篇 |
2006年 | 4876篇 |
2005年 | 4346篇 |
2004年 | 4083篇 |
2003年 | 4049篇 |
2002年 | 3342篇 |
2001年 | 2823篇 |
2000年 | 1516篇 |
1999年 | 470篇 |
1998年 | 268篇 |
1997年 | 199篇 |
1996年 | 175篇 |
1995年 | 128篇 |
1994年 | 92篇 |
1993年 | 105篇 |
1992年 | 83篇 |
1991年 | 85篇 |
1990年 | 40篇 |
1989年 | 74篇 |
1988年 | 20篇 |
1987年 | 26篇 |
1986年 | 27篇 |
1985年 | 28篇 |
1984年 | 62篇 |
1983年 | 38篇 |
1982年 | 39篇 |
1981年 | 10篇 |
1980年 | 17篇 |
1979年 | 18篇 |
1978年 | 14篇 |
1977年 | 3篇 |
1976年 | 1篇 |
1975年 | 3篇 |
排序方式: 共有10000条查询结果,搜索用时 9 毫秒
981.
《Journal of Statistical Computation and Simulation》2012,82(1-4):175-196
The evaluation of hazards from complex, large scale, technologically advanced systems often requires the construction of computer implemented mathematical models. These models are used to evaluate the safety of the systems and to evaluate the consequences of modifications to the systems. These evaluations, however, are normally surrounded by significant uncertainties related to the uncertainty inherent in natural phenomena such as the weather and those related to uncertainties in the parameters and models used in the evaluation. Another use of these models is to evaluate strategies for improving information used in the modeling process itself. While sensitivity analysis is useful in defining variables in the model that are important, uncertainty analysis provides a tool for assessing the importance of uncertainty about these variables. A third complementary technique, is decision analysis. It provides a methodology for explicitly evaluating and ranking potential improvements to the model. Its use in the development of information gathering strategies for a nuclear waste repository are discussed in this paper. 相似文献
982.
《统计学通讯:模拟与计算》2012,41(6):688-709
We begin by definition of semi-Markov flow and discussion of its properties. Asymptotic behavior of multi-server and single-server queueing systems is studied under assumption of time-compression or service time growth. The results obtained are used for calculation of large systems reliability. Statistical estimates of parameters involved are also provided. 相似文献
983.
《统计学通讯:理论与方法》2012,41(13-14):2305-2320
We consider shrinkage and preliminary test estimation strategies for the matrix of regression parameters in multivariate multiple regression model in the presence of a natural linear constraint. We suggest a shrinkage and preliminary test estimation strategies for the parameter matrix. The goal of this article is to critically examine the relative performances of these estimators in the direction of the subspace and candidate subspace restricted type estimators. Our analytical and numerical results show that the proposed shrinkage and preliminary test estimators perform better than the benchmark estimator under candidate subspace and beyond. The methods are also applied on a real data set for illustrative purposes. 相似文献
984.
《Journal of Statistical Computation and Simulation》2012,82(12):987-1001
In this article, we develop inference tools for an effect size parameter in a paired experiment. A class of estimators is defined that includes natural, shrinkage and shrinkage preliminary test estimators. The shrinkage and preliminary test methods incorporate uncertain prior information on the parameter. This information may be available in the form of a realistic guess on the basis of the experimenter’s knowledge and experience, which can be incorporated into the estimation process to increase the efficiency of the estimator. Asymptotic properties of the proposed estimators are investigated both analytically and computationally. A simulation study is also conducted to assess the performance of the estimators for moderate and large samples. For illustration purposes, the method is applied to a data set. 相似文献
985.
《Journal of Statistical Computation and Simulation》2012,82(12):1407-1423
In this paper, we consider the superimposed exponential signals in zero-mean multiplicative and additive noise when all the noise are independently and identically distributed. We use a three-step iterative procedure to estimate the frequencies of the considered model. It is observed that the estimators are consistent and work quite well in terms of biases and mean square errors. Moreover, the convergence rate of the estimators attains O p (N ?3/2), which is the best convergence rate in the case of only additive noise and constant amplitude. 相似文献
986.
《Journal of Statistical Computation and Simulation》2012,82(2):233-258
It is well known that in a traditional outlier-free situation, the generalized quasi-likelihood (GQL) approach [B.C. Sutradhar, On exact quasilikelihood inference in generalized linear mixed models, Sankhya: Indian J. Statist. 66 (2004), pp. 261–289] performs very well to obtain the consistent as well as the efficient estimates for the parameters involved in the generalized linear mixed models (GLMMs). In this paper, we first examine the effect of the presence of one or more outliers on the GQL estimation for the parameters in such GLMMs, especially in two important models such as count and binary mixed models. The outliers appear to cause serious biases and hence inconsistency in the estimation. As a remedy, we then propose a robust GQL (RGQL) approach in order to obtain the consistent estimates for the parameters in the GLMMs in the presence of one or more outliers. An extensive simulation study is conducted to examine the consistency performance of the proposed RGQL approach. 相似文献
987.
988.
Thaung Lwin 《Journal of applied statistics》2012,39(8):1623-1641
The problem of comparing, contrasting and combining information from different sets of data is an enduring one in many practical applications of statistics. A specific problem of combining information from different sources arose in integrating information from three different sets of data generated by three different sampling campaigns at the input stage as well as at the output stage of a grey-water treatment process. For each stage, a common process trend function needs to be estimated to describe the input and output material process behaviours. Once the common input and output process models are established, it is required to estimate the efficiency of the grey-water treatment method. A synthesized tool for modelling different sets of process data is created by assembling and organizing a number of existing techniques: (i) a mixed model of fixed and random effects, extended to allow for a nonlinear fixed effect, (ii) variogram modelling, a geostatistical technique, (iii) a weighted least squares regression embedded in an iterative maximum-likelihood technique to handle linear/nonlinear fixed and random effects and (iv) a formulation of a transfer-function model for the input and output processes together with a corresponding nonlinear maximum-likelihood method for estimation of a transfer function. The synthesized tool is demonstrated, in a new case study, to contrast and combine information from connected process models and to determine the change in one quality characteristic, namely pH, of the input and output materials of a grey-water filtering process. 相似文献
989.
Double sampling scheme is used when cheap auxiliary variables may be measured to improve the estimation of a finite population parameter. Several estimators for population mean, ratio of means and variance are available, when two dependent samples are drawn. However, there are few proposals for the case of independent samples. In this paper both cases of dependent and independent samples are dealt with. A general approach for estimating a finite population parameter is given, showing that all the proposed estimators are particular cases of the same general class. The minimum variance bound for any estimator in this class is provided (at the first order of approximation). Furthermore, an optimal estimator which reaches this minimum is found. 相似文献
990.
Joachim Merz 《Allgemeines Statistisches Archiv》2004,88(4):451-472
Zusammenfassung: In dieser Studie wird ein Konzept zur Kumulation von laufenden
Haushaltsbudgetbefragungen im Rahmen des Projektes Amtliche Statistik und sozioökonomische
Fragestellungen entwickelt und zur Diskussion gestellt. Dafür werden die theoretischen
Grundlagen und Bausteine gelegt und die zentrale Aufgabe einer strukturellen
demographischen Gewichtung mit einem Hochrechnungs–/Kalibrierungsansatz auf informationstheoretischer
Basis gelöst.Vor dem Hintergrund der Wirtschaftsrechnungen des Statistischen Bundesamtes (Lfd.
Wirtschaftsrechnungen und EVS) wird darauf aufbauend ein konkretes Konzept für die
Kumulation von jährlichen Haushaltsbudgetbefragungen vorgeschlagen. Damit kann das
Ziel einer Kumulation von Querschnitten mit einer umfassenderen Kumulationsstichprobe
für tief gegliederte Analysen erreicht werden. Folgen sollen die Simulationsrechnungen
zur Evaluation des Konzepts.
Summary: In this study a concept for cumulating periodic household surveys within the frame of the project Official Statistics and Socio–Economic Questions is developed and asks for discussion. We develop the theoretical background and solve the central task of a structural demographic weighting/calibration based on an information theoretical approach.Based on the household budget surveys of the Federal Statistical Office (Periodic Household Budget Surveys and Income and Consumption Sample (EVS)) a practical concept is proposed to cumulate yearly household surveys. This allows a cumulation of cross–sections by a comprehensive cumulated sample for deeply structured analyses. In a following study this concept shall be evaluated.相似文献