全文获取类型
收费全文 | 944篇 |
免费 | 35篇 |
专业分类
管理学 | 31篇 |
人口学 | 2篇 |
丛书文集 | 14篇 |
理论方法论 | 2篇 |
综合类 | 142篇 |
统计学 | 788篇 |
出版年
2023年 | 8篇 |
2022年 | 9篇 |
2021年 | 11篇 |
2020年 | 18篇 |
2019年 | 34篇 |
2018年 | 30篇 |
2017年 | 58篇 |
2016年 | 30篇 |
2015年 | 39篇 |
2014年 | 32篇 |
2013年 | 243篇 |
2012年 | 75篇 |
2011年 | 26篇 |
2010年 | 36篇 |
2009年 | 24篇 |
2008年 | 31篇 |
2007年 | 21篇 |
2006年 | 20篇 |
2005年 | 22篇 |
2004年 | 26篇 |
2003年 | 13篇 |
2002年 | 17篇 |
2001年 | 19篇 |
2000年 | 15篇 |
1999年 | 21篇 |
1998年 | 18篇 |
1997年 | 7篇 |
1996年 | 9篇 |
1995年 | 8篇 |
1994年 | 7篇 |
1993年 | 10篇 |
1992年 | 5篇 |
1991年 | 2篇 |
1990年 | 5篇 |
1989年 | 8篇 |
1988年 | 4篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 3篇 |
1983年 | 5篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1975年 | 1篇 |
排序方式: 共有979条查询结果,搜索用时 492 毫秒
11.
In this paper, the task of determining expected values of sample moments, where the sample members have been selected based on noisy information, is considered. This task is a recurring problem in the theory of evolution strategies. Exact expressions for expected values of sums of products of concomitants of selected order statistics are derived. Then, using Edgeworth and Cornish-Fisher approximations, explicit results that depend on coefficients that can be determined numerically are obtained. While the results are exact only for normal populations, it is shown experimentally that including skewness and kurtosis in the calculations can yield greatly improved results for other distributions. 相似文献
12.
给出了初等r-循环矩阵可逆的充要条件及逆矩阵的表达式;对奇异的初等r-循环矩阵给出了A的一个g-逆G(满足AGA=A,GAG=G)及Moore-penrose广义逆矩阵的表达式. 相似文献
13.
The maximum likelihood estimation for the critical points of the failure rate and the mean residual life function are presented
in the case of mixture inverse Gaussian model. Several important data sets are analyzed from this point of view. For each
of the data sets, Bootstrapping is used to construct confidence intervals of the critical points. 相似文献
14.
Clemens Heuberger 《Journal of Combinatorial Optimization》2004,8(3):329-361
Given a (combinatorial) optimization problem and a feasible solution to it, the corresponding inverse optimization problem is to find a minimal adjustment of the cost function such that the given solution becomes optimum.Several such problems have been studied in the last twelve years. After formalizing the notion of an inverse problem and its variants, we present various methods for solving them. Then we discuss the problems considered in the literature and the results that have been obtained. Finally, we formulate some open problems. 相似文献
15.
叶剑虹 《中南林业科技大学学报(社会科学版)》2012,6(6):155-156,186
在当前我国产品设计相对薄弱,企业资金投入不足的情形下,较难自主创新,模仿创新成为产品设计跨越式发展的必经之路。模仿创新相较率先创新具有后发优势,反而能设计出占据市场主导地位和最具经济效益的产品。但模仿创新不是恶劣的伪造,重点在于借鉴改造,从而形成自身风格。 相似文献
16.
17.
The asymptotic variance of the maximum likelihood estimate is proved to decrease when the maximization is restricted to a subspace that contains the true parameter value. Maximum likelihood estimation allows a systematic fitting of covariance models to the sample, which is important in data assimilation. The hierarchical maximum likelihood approach is applied to the spectral diagonal covariance model with different parameterizations of eigenvalue decay, and to the sparse inverse covariance model with specified parameter values on different sets of nonzero entries. It is shown computationally that using smaller sets of parameters can decrease the sampling noise in high dimension substantially. 相似文献
18.
NICOLAI BISSANTZ HOLGER DETTE KATHARINA PROKSCH 《Scandinavian Journal of Statistics》2012,39(2):305-322
Abstract. We consider the problem of testing parametric assumptions in an inverse regression model with a convolution‐type operator. An L 2 ‐type goodness‐of‐fit test is proposed which compares the distance between a parametric and a non‐parametric estimate of the regression function. Asymptotic normality of the corresponding test statistic is shown under the null hypothesis and under a general non‐parametric alternative with different rates of convergence in both cases. The feasibility of the proposed test is demonstrated by means of a small simulation study. In particular, the power of the test against certain types of alternative is investigated. Finally, an empirical example is provided, in which the proposed methods are applied to the determination of the shape of the luminosity profile of the elliptical galaxy NGC 5017. 相似文献
19.
《Journal of Statistical Computation and Simulation》2012,82(11):1317-1329
This contribution deals with the Monte Carlo simulation of generalized Gaussian random variables. Such a parametric family of distributions has been proposed in many applications in science to describe physical phenomena and in engineering, and it seems to be also useful in modelling economic and financial data. For values of the shape parameter α within a certain range, the distribution presents heavy tails. In particular, the cases α=1/3 and α=1/2 are considered. For such values of the shape parameter, different simulation methods are assessed. 相似文献
20.
《Journal of Statistical Computation and Simulation》2012,82(3):287-299
The conventional Shewhart-type control chart is developed essentially on the central limit theorem. Thus, the Shewhart-type control chart performs particularly well when the observed process data come from a near-normal distribution. On the other hand, when the underlying distribution is unknown or non-normal, the sampling distribution of a parameter estimator may not be available theoretically. In this case, the Shewhart-type charts are not available. Thus, in this paper, we propose a parametric bootstrap control chart for monitoring percentiles when process measurements have an inverse Gaussian distribution. Through extensive Monte Carlo simulations, we investigate the behaviour and performance of the proposed bootstrap percentile charts. The average run lengths of the proposed percentage charts are investigated. 相似文献