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1.
考虑了多元t-copula的上尾象限相依指数和上尾极值相依指数,该t-copula是在相依结构下定义的．由于多元连续型随机变量的copula函数关于严格单调递增变换具有不变性质,由此推导了多元t-copula的尾相依指数的精确表达式,得到的结果明显比以往文献给出的结论更加简洁．然后,讨论了这2个相依指数关于相关系数的局部单调性质：上尾极值相依指数关于相关系数是严格单调递增的,但上尾象限相依指数的单调性比较复杂．通过蒙特卡罗模拟数据验证了结果的正确性．同时,发现所有结论可以推广到生成随机变量是正则变化的分布类中． 相似文献
2.
皮尔逊Ⅲ型分布参数估计方法的对比分析 总被引：4，自引：0，他引：4
介绍了在我国水文频率计算中常使用的皮尔逊Ⅲ型（P-Ⅲ型）分布的几种参数估计方法,详细地论述了目前最新的线性矩法。通过对各种方法的统计试验的比较分析,得出线性矩法的无偏性和稳健性较其他方法为优。 相似文献
3.
Drought, along with flood, earthquake and vol- cano, is a recurring natural disaster event in many parts of the world, with severe social, economic and environmental impacts. The onset and the termination of drought are not very clear, making the drought event difficult to distinguish[1]. Some of these situa- tions also lead to the absence of a clear definition of the drought[2,3]. Objectives of the present paper are to investigate the problem of drought identification under adjusted runoff us… 相似文献
4.
Ulrich Schroeders Alexander Robitzsch Stefan Schipolowski 《Journal of Educational Measurement》2014,51(4):400-418
C‐tests are a specific variant of cloze tests that are considered time‐efficient, valid indicators of general language proficiency. They are commonly analyzed with models of item response theory assuming local item independence. In this article we estimated local interdependencies for 12 C‐tests and compared the changes in item difficulties, reliability estimates, and person parameter estimates for different modeling approaches: (a) Rasch, (b) testlet, (c) partial credit, and (d) copula models. The results are complemented with findings of a simulation study in which sample size, number of testlets, and strength of residual correlations between items were systematically manipulated. Results are discussed with regard to the pivotal question whether residual dependencies between items are an artifact or part of the construct. 相似文献
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地方高校体育院系服务区域体育文化建设的研究 总被引：1，自引：0，他引：1
吴长稳 《牡丹江教育学院学报》2010,(3):89-90
服务地方是高等学校的的职能之一,地方高校应利用所拥有的人才优势、资源优势、科研优势、设备优势,并与地方政府的体育文化建设的政策相契合,解决地方体育文化建设过程中存在的问题,为构建和谐社会而努力。 相似文献
7.
魏力 《四川三峡学院学报》2014,(2):37-40
产业的转移和承接既是区域间产业调整的互动过程,又是区域内产业结构调整的手段。欠发达地区通过承接发达地区的成熟产业,开发和利用本地丰富的自然资源和廉价劳动力,来推动当地经济发展。目前,虽然皖江城市带通过充分利用安徽省出台的一系列配套措施,在承接产业转移方面取得了一定的成就,但还面临着一些问题,通过数学建模的方法对皖江城市带与相关地区的资源禀赋的分析,可以找到一些解决问题的方法。 相似文献
8.
In this article we describe a structural equation modeling (SEM) framework that allows nonnormal skewed distributions for the continuous observed and latent variables. This framework is based on the multivariate restricted skew t distribution. We demonstrate the advantages of skewed SEM over standard SEM modeling and challenge the notion that structural equation models should be based only on sample means and covariances. The skewed continuous distributions are also very useful in finite mixture modeling as they prevent the formation of spurious classes formed purely to compensate for deviations in the distributions from the standard bell curve distribution. This framework is implemented in Mplus Version 7.2. 相似文献
9.
A new approach is proposed to improve the general identification algorithm of multidimensional systems using wavelet networks. The general algorithm involves mapping vector input into its norm to avoid problem of dimensionality in construction multidimensional wavelet basis functions. Thus, the basis functions are spherically symmetric without direction selectivity. In order to restore the direction selectivity, the improved approach weights the input variables before mapping it into a scalar form. The weights can be obtained using universal optimization algorithms. Generally, only local optimal weights are obtained. Even so, performance of identification can be improved. 相似文献
10.
罗曼懿 《赣南师范学院学报》2010,31(6)
在Copula函数广泛应用于金融领域的背景下,给出了Copula函数的定义及相关定理的理论基础,运用Sklar′s定理具体构造二元Pareto分布的Copula函数.我们注重利用Copula函数相依性测度,通过不同的分布模型求一致性与相关性系数作为实例.在此基础上,引入图像工具作为进行相依性研究的方法. 相似文献
11.
基本公共服务均等化是公平正义在公共服务领域的体现。由于自然资源、社会历史条件以及制度等因素的影响,西部民族地区在基础教育、基本医疗、社会保障及道路基础设施等基本公共服务方面与东部地区差距巨大。要缩小基本公共服务的地区差距,首先要促进西部民族地区经济发展;其次要完善转移支付制度;最后,要转变西部民族地区地方政府职能,完善公共服务的多元供给制度。 相似文献
12.
郭培俊 《浙江工贸职业技术学院学报》2016,(1):7-10
为理解通识教育概念,采用思辨法,产生新感悟：通识为隐性知识;通识似水;通为道,道常无为,而无不为。以开发《科学与生活》为例,得出高职通识教育微课程教材内容具有八大特性和编写风格的八大特征。 相似文献
13.
陆健 《南通职业大学学报》2014,(3):81-85
研究在跨越城郊的区域铺设输油管线的优化设计。提出目标测算的概念用以把握大方向,针对非特定的一般性参数条件,运用数学建模的方法,构造目标函数及其可行域奠定分析基础,通过恰当的多变量置换推导出最优解的解析结果,并且从严格意义上证明其最优性。对于参数出现异常的情形,采用＂越界回归＂的方法,给出了应对策略以及计算公式,同时阐明了该方法的合理性和有效性。 相似文献
14.
介绍了南津关专用水文站设站目的、水文泥沙测验及水文泥沙科研成果在葛洲坝工程建设中的运用。 相似文献
15.
对西洞庭湖水系的安乡、自治局（二）、石龟山、官垸4个水文站62个泥沙颗分细沙部分（粒径小于0．062mm）水样样本,用传统的吸管法和BT-1500型离心沉降式粒度分布仪法进行同粒径级比测分析,介绍率定仪器参数和确定误差标准的基本方法以及在应用过程中注意的事项,供泥沙颗粒分析工作者在实际分析工作应用中借鉴。 相似文献
16.
利用扩展乘数法讨论了多元线性正算子改造为逼近多元无界连续函数的渐近估计 ,给出了具有一般性的渐近公式 作为实例 ,研究了多元非乘积型的Landau多项式算子逼近多元无界连续函数的渐近估计式 ,推广了前人的若干结论 相似文献
17.
Based on variable structure control (VSC) and fuzzy local controller network (FLCN), a new design method of robust gain-scheduling
control is proposed in this paper. The proper sliding-modes and the tendency-rates for general operation-points are introduced
such that the system gets into the sliding-modes’ motion as soon as possible and has the desired performance. Its good performance
is due to the robustness of VSC. However, any local controller works well only in the local region of a specified operation-point.
In this paper functions similar to the fuzzy-attributed function in fuzzy-systems are introduced to form FLCN. The simulation
results showed that the presented method is feasible and acceptable.
Project supported by the Natural Science Foundation of China (NSFC: 69934030) and the Zhejiang Provincial Natural Science
Foundation of China (ZJPNSFC: ZD9905). 相似文献
18.
根据I-型垂直密度表示及II-型垂直密度表示,分析垂直密度表示（Vertical Density Representation,简记为VDR）的提出与Lebesgue积分创立的异曲同工之处.阐述VDR在随机数生成、概率分布构造、多元分布拟合优度检验等方面的应用.垂直密度表示是一种特殊类型的变量变换,可用以探究概率分布的内在特性. 相似文献
19.
A parallel system with two active components and a cold standby unit is studied in this paper. The two simultaneously working components are dependent and the copula function is used to model their dependence. An explicit expression is obtained for the mean time to failure of the system in terms of the copula function and marginal lifetime distributions in two different cases As an application, numerical calculations are presented corresponding to two different copula functions and marginal lifetime distributions. 相似文献
20.
王运锋 《重庆职业技术学院学报》2012,(5):80-82
按照《国家中长期教育改革与发展规划纲要（2010-2020年）》对高等教育发展提出的要求,通过对欠发达地区高校师资队伍一般性特点和韩山师范学院师资队伍的建设现状进行比较分析,提出欠发达地区地方师范院校教师队伍建设的可持续性发展策略。 相似文献