全文获取类型
收费全文 | 156篇 |
免费 | 1篇 |
专业分类
管理学 | 41篇 |
民族学 | 2篇 |
人口学 | 5篇 |
丛书文集 | 8篇 |
综合类 | 19篇 |
社会学 | 5篇 |
统计学 | 77篇 |
出版年
2020年 | 2篇 |
2019年 | 3篇 |
2018年 | 5篇 |
2016年 | 4篇 |
2015年 | 5篇 |
2014年 | 2篇 |
2013年 | 39篇 |
2012年 | 9篇 |
2011年 | 9篇 |
2010年 | 5篇 |
2009年 | 8篇 |
2008年 | 7篇 |
2007年 | 9篇 |
2006年 | 3篇 |
2005年 | 4篇 |
2004年 | 3篇 |
2003年 | 1篇 |
2002年 | 2篇 |
2001年 | 1篇 |
2000年 | 3篇 |
1999年 | 1篇 |
1998年 | 3篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 4篇 |
1981年 | 3篇 |
1980年 | 3篇 |
排序方式: 共有157条查询结果,搜索用时 21 毫秒
11.
中国最早的网络移民自始至终伴随了中国互联网的发展,他们的网络使用行为形成了一段不长但至少可以追溯的历史。早期的网络社交将个体从现实物理空间局限中解放出来,具有高蹈于日常生活之上的虚拟色彩;随着网络空间中现实好友的增多和移动位置社交的兴起,网络空间的虚拟色彩渐渐褪去;如今,日常生活中的人际交往不再是在某一单一空间中进行,人们不断地在物理空间与网络空间切换,亦或同时在场。 相似文献
12.
The maximum expected covering location problem (MEXCLP) is reformulated using a separable programming approach. The resulting formulation—nonlinear maximum expected covering location problem (NMEXCLP)—guarantees optimality and also solves more quickly than previous heuristic approaches. NMEXCLP allows two important extensions. First, minor formulation changes allow the specification of the minimum number of times each node is to be covered in order to satisfy expected coverage criteria. Second, coverage matrices can be constructed that consider two different types of coverage simultaneously. Both extensions are useful for ambulance location problems and are demonstrated in that setting. 相似文献
13.
学界所谓三国能在群雄混战中割据一方,各有立国之本:魏占天时,吴占地利,蜀占人和。其实,得天下的战略表面看来有天地人各种因素,说穿了只有一条:人才,尤其是谋士。谋士集团在三国鼎立中有着举足轻重的作用。 相似文献
14.
The Web proxy location problem in general networks is an NP-hard problem. In this paper, we study the problem in networks showing a general tree of rings topology. We improve the results of the tree case in literature and get an exact algorithm with time complexity O(nhk), where n is the number of nodes in the tree, h is the height of the tree (the server is in the root of the tree), and k is the number of web proxies to be placed in the net. For the case of networks with a general tree of rings topology we present an exact algorithm with O(kn
2) time complexity.This research has been supported by NSF of China (No. 10371028) and the Educational Department grant of Zhejiang Province (No. 20030622). 相似文献
15.
《Journal of Statistical Computation and Simulation》2012,82(5):391-401
The three parameters involved are scale a , shape 𝜌 , and location s . Maximum likelihood estimators are (hata, hatrho, hats) . Using recent work on the second order variances, skewness, and kurtosis we establish the facts, that if the location parameter s is to be estimated, then the asymptotic variances only exist if 𝜌 >2, asymptotic skewness only exists if 𝜌 >3, and 2nd order variances and third order fourth central moments only exist if 𝜌 >4. The result of these limitations is that in general very large sample sizes may be needed to avoid inference problems. We also include new continued fractions for the asymptotic covariances of the maximum likelihood estimators considered. 相似文献
16.
文章对<众数之误>一文不准确之处进行了分析,指出众数就是位置平均数,现行统计教材中关于众数的内容基本正确,并希望与该文作者及读者进行交流. 相似文献
17.
Koenker Roger 《Econometric Reviews》1982,1(2):213-255
This survey of recent developments in robust estimation and inference is directed primarily toward econometricians. It is argued that many of the techniques in common use in econometrics are highly sensitive to unverified hypotheses. Recent progress in designing alternative robust procedures is described and some prospects for future developments are discussed. 相似文献
18.
Bounded-width sequential confidence intervals and sequential tests for regression parameter based on M-estimators are extended to the case where the score-functions generating the M-estimators have jump-discontinuities. In the context of the asymptotic normality of the stopping variable, for the confidence interval problem, it is observed that the jump-discontinuities induce a slower rate of convergence. The proofs of the main theorems rest on the weak convergence of some related processes and this is also studied. 相似文献
19.
For each positive integer k, a set of k-principal points of a distribution is the set of k points that optimally represent the distribution in terms of mean squared distance. However, explicit form of k-principal points is often difficult to obtain. Hence a theorem established by Tarpey et al. (1995) has been influential in the literature, which states that when the distribution is elliptically symmetric, any set of k-principal points is in the linear subspace spanned by some principal eigenvectors of the covariance matrix. This theorem is called a “principal subspace theorem”. Recently, Yamamoto and Shinozaki (2000b) derived a principal subspace theorem for 2-principal points of a location mixture of spherically symmetric distributions. In their article, the ratio of mixture was set to be equal. This article derives a further result by considering a location mixture with unequal mixture ratio. 相似文献
20.
The generalized secant hyperbolic distribution (GSHD) was recently introduced as a modeling tool in data analysis. The GSHD is a unimodal distribution that is completely specified by location, scale, and shape parameters. It has also been shown elsewhere that the rank procedures of location are regular, robust, and asymptotically fully efficient. In this article, we study certain tail weight measures for the GSHD and introduce a tail-adaptive rank procedure of location based on those tail weight measures. We investigate the properties of the new adaptive rank procedure and compare it to some conventional estimators. 相似文献