基于二层模糊综合决策的图书馆绩效评估模型

对当前图书馆绩效评估的体系和方法进行了研究,给出了基于二层模糊综合决策的图书馆绩效评估模型,结合模型对评估结果进行了分析并提出了有关改进工作的建议.     

带有二次订购和二次销售的报童问题

本文提出二次进货二次销售的报童模型 ,并分析了新模型与经典报童问题和带有反馈生产模型的最优订购量及收益关系 ,分析了模型的灵敏度 ,服务水平等 .     

多标准等级判别模型在信用评级中的应用研究

在对目前我国信用评级方法应用现状分析的基础上,提出改进的多标准等级判别模型.并将该模型应用于商业银行信用风险评估中.通过对银行五级分类贷款样本的实证研究,证实了该判别模型的有效性和先进性.     

卫生系统的评价模型(英文)

构造了一个模糊数学模型和一个灰色系统预测模型来评估卫生系统的好坏并预测其发展趋势.在第一个模型中,我们通过作用于隶属向量上的灵敏度创造出一种计算权重的特殊方法.从本质上讲,作用于隶属向量上的灵敏可以通过作用于隶属函数上的灵敏度求得.基于上述基本思想,我们创造出两种计算作用于隶属向量上的灵敏度的方法.     

基于AHP-Fuzzy方法的企业技术创新能力评估模型的建立及其应用

面向 2 1世纪知识经济的挑战 ,对企业技术创新能力进行科学的评估对我国经济的长远发展具有重要的战略意义 .本文在对企业技术创新能力进行知识描述的基础上 ,首先建立了企业技术创新能力综合评估的指标体系 ,继而提出了基于 AHP-Fuzzy方法上的企业技术创新能力评估模型 ,这为企业科学地进行技术创新能力评估提供了一定的理论指导 .文末 ,通过实证分析说明了该模型在实际中的应用 .     

考虑区间删失数据的I-最优加速寿命试验方案

为了避免经典方法中Fisher信息矩阵的繁琐计算,并考虑两个或更多应力因子对加速寿命试验的影响,提出了基于区间删失数据的I最优加速寿命试验方案并进行了相应的灵敏度分析.将产品的正常使用条件考虑为一个应力水平组合的区域,I最优准则使得在这个区域上产品寿命的平均预测方差最小.假定失效时间分布服从Cox比例风险模型(Proportional Hazard Model),继而对区间删失数据使用广义线性模型(Generalized Linear Model)方法以得到I最优准则下的加速寿命试验方案,最后从模型参数、检测区间数、样本量、试验时间等角度进行了试验方案的灵敏度分析,验证了试验方案的稳健性,并讨论了如何利用这些因素来降低试验敏感性.     

教学质量评估的定量比较评价模型

依据华南农业大学 2 0 0 2学年第一学期课堂教学质量评估卡的调查数据 ,利用层次分析法建立了学生评价教师教学质量的定量评价模型 P =WR,并应用该模型对担任数学类课程的 1 3位教师的课堂教学质量作了定量比较分析 .分析结果表明 ,近几年来的扩招 ,对教师的教学提出了新的要求 ,在教学内容、教学手段、教学方法等方面 ,应做出相应的调整 ,才能收到好的教学效果 .     

市场低迷时期证券投资风险的度量

当股票市场处于疲软状态，即通常所说的熊市时，证券投资风险的评估和规避就显得尤为重要。本从保险中的破产理论出发，运用复合泊松过程的方法，在一个事例的基础上，提出一种当市场比较疲软时在短期内评估投资风险的方法，并以2002年9月2日到2002年12月31日这79个交易日中具有代表性的一支股票——深发展(000001)为例，进行了模型的求解和分析，并在此基础上提出了几套改进模型的方案和本方法的扩展应用。     

最优波动率模型选择及其在黄金市场中的应用

文章先总结了波动率模型过去的研究，并对不同波动率模型的评估提出三种方法，然后讨论了这些方法在黄金市场波动率预测中的应用。通过分析黄金市场1975年到2004年的数据，得出的结论是，如果基于样本外四期预测误差的评估，EWMA模型较优；如果基于样本外四期预测的R平方的评估，T-GARCH模型较优；如果基于VAR损失函数的真实性检验评估，EWMA模型较优。最后对未来关于金融市场波动率的研究提出一些建议。     

市场低迷时期证券投资风险的度量

当股票市场处于疲软状态，即通常所说的熊市时，证券投资风险的评估和规避就显得尤为重要。本从保险中的破产理论出发，运用复合泊松过程的方法，在一个事例的基础上，提出一种当市场比较疲软时在短期内评估投资风险的方法，并以2002年9月2日到2002年12月31日这79个交易日中具有代表性的一支股票——深发展(000001)为例，进行了模型的求解和分析，并在此基础上提出了几套改进模型的方案和本方法的扩展应用。     

HIV low viral load persistence under treatment: Insights from a model of cell-to-cell viral transmission

HIV infection persists despite long-term administration of antiretroviral therapy. The mechanisms underlying HIV persistence are not fully understood. Direct viral transmission from infected to uninfected cells (cell-to-cell transmission) may be one of them. During cell-to-cell transmission, multiple virions are delivered to an uninfected cell, making it possible that at least one virion can escape HIV drugs and establish infection. In this paper, we develop a mathematical model that includes cell-to-cell viral transmission to study HIV persistence. During cell-to-cell transmission, it is assumed that various number of virus particles are transmitted with different probabilities and antiretroviral therapy has different effectiveness in blocking their infection. We analyze the model by deriving the basic reproduction number and investigating the stability of equilibria. Sensitivity analysis and numerical simulation show that the viral load is still sensitive to the change of the treatment effectiveness in blocking cell-free virus infection. To reduce this sensitivity, we modify the model by including density-dependent infected cell death or HIV latent infection. The model results suggest that although cell-to-cell transmission may have reduced susceptibility to HIV drugs, HIV latency represents a major reason for HIV persistence in patients on suppressive treatment.     

一些图的Mycielski图的均匀邻强边染色

如果图G的一个正常边染色满足相邻点的色集不同,且任意两种颜色所染边数目相差不超过1,则称为均匀邻强边染色,其所用最少染色数称为均匀邻强边色数.本文得到了路、圈、星和扇的Mycielski图的均匀邻强边色数.     

Cluster synchronization in colored community network with different order node dynamics

In this paper, a colored community network model with different order nodes dynamics is introduced for the first time. The color of nodes or edges are assumed to be identical if they belong to the same community and nonidentical if they belong to different communities. The color of edges between any pair of communities are assumed to be identical if they connect the same pair of communities and nonidentical if they connect different pair of communities. Further, the order of the node dynamics in different communities can be totally different. Firstly, based on the Lyapunov stability theory, adaptive feedback controllers are designed for achieving cluster synchronization. Secondly, periodically intermittent controllers are designed for achieving cluster synchronization and the synchronization conditions are derived by using mathematical induction method and the analysis technique. Finally, several numerical examples are provided to illustrate the effectiveness of the derived theoretical results.     

一种基于Split-findmin和Set-maxima的最小支撑树灵敏度分析方法

本文首先根据最小支撑树的截性质和圈性质给出了灵敏度分析的基本公式,然后基于现代图论算法中经典的Split—findmian数据结构介绍了树上边的灵敏度分析算法,最后将非树边的灵敏度分析转化为已有成熟的算法的Set—maxima问题进行处理.     

Discriminant Analysis in Schizophrenia based on Neural Network

In this paper, we use neural network to classify schizophrenia patients and healthy control subjects. Based on 4005 high dimensions feature space consist of functional connectivity about 63 schizophrenic patients and 57 healthy control as the original data, attempting to try different dimensionality reduction methods, different neural network model to find the optimal classification model. The results show that using the Mann-Whitney U test to select the more discrimination features as input and using Elman neural network model for classification to get the best results, can reach a highest accuracy of 94.17%, with the sensitivity being 92.06% and the specificity being 96.49%. For the best classification neural network model, we identified 34 consensus functional connectivities that exhibit high discriminative power in classification, which includes 26 brain regions, particularly in the thalamus regions corresponding to the maximum number of functional connectivity edges, followed by the cingulate gyrus and frontal region.     

Link Prediction for Partially Observed Networks

Link prediction is one of the fundamental problems in network analysis. In many applications, notably in genetics, a partially observed network may not contain any negative examples, that is, edges known for certain to be absent, which creates a difficulty for existing supervised learning approaches. We develop a new method that treats the observed network as a sample of the true network with different sampling rates for positive (true edges) and negative (absent edges) examples. We obtain a relative ranking of potential links by their probabilities, using information on network topology as well as node covariates if available. The method relies on the intuitive assumption that if two pairs of nodes are similar, the probabilities of these pairs forming an edge are also similar. Empirically, the method performs well under many settings, including when the observed network is sparse. We apply the method to a protein–protein interaction network and a school friendship network.     

Transitions in geometric minimum spanning trees

We study some combinatorial and algorithmic problems associated with an arbitrary motion of input points in space. The motivation for such an investigation comes from two different sources:computer modeling andsensitivity analysis. In modeling, the dynamics enters the picture since geometric objects often model physical entities whose positions can change over time. In sensitivity analysis, the motion of the input points might represent uncertainties in the precise location of objects. The main results of the paper deal with state transitions in the minimum spanning tree when one or more of the input points move arbitrarily in space. In particular, questions of the following form are addressed: (i) How many different minimum spanning trees can arise if one point moves while the others remain fixed? (ii) When does the minimum spanning tree change its topology if all points are allowed to move arbitrarily?     

The product representation of a locally dependent random graph

Directed graphs with random black and white colourings of edges such that the colours of edges from different vertices are mutually independent are called locally dependent random graphs. Two random graphs are equivalent if they cannot be distinguished from percolation processes on them if only the vertices are seen. A necessary and sufficient condition is given for when a locally dependent random graph is equivalent to a product random graph; that is one in which the edges can be grouped in such a way that within each group the colours of the edges are equivalent and between groups they are independent. As an application the random graph corresponding to a spatial general epidemic model is considered.     

Une justification du modèle de coques de Naghdi

We consider a thin linearly elastic loaded shell allowing non-zero inextensional displacements. Under some assumptions on the loads, we prove that the tangential and normal parts of the stress tensor are small compared with the transverse pan, when the thickness of the shell goes to zero. Besides, the displacement vector and the transverse pan of the stress tensor are of the same order of magnitude with respect to the thickness when the material constituting the shell is Isotropic and homogeneous. The limit model, which is a flexural model, can also be obtained from Naghdi's model but not from Koiter's model. In some cases of anisotropic materials, the displacement vector is of a larger order of magnitude than the stress tensor, when the thickness goes to zero.     

Nuclear norm minimization for the planted clique and biclique problems

We consider the problems of finding a maximum clique in a graph and finding a maximum-edge biclique in a bipartite graph. Both problems are NP-hard. We write both problems as matrix-rank minimization and then relax them using the nuclear norm. This technique, which may be regarded as a generalization of compressive sensing, has recently been shown to be an effective way to solve rank optimization problems. In the special case that the input graph has a planted clique or biclique (i.e., a single large clique or biclique plus diversionary edges), our algorithm successfully provides an exact solution to the original instance. For each problem, we provide two analyses of when our algorithm succeeds. In the first analysis, the diversionary edges are placed by an adversary. In the second, they are placed at random. In the case of random edges for the planted clique problem, we obtain the same bound as Alon, Krivelevich and Sudakov as well as Feige and Krauthgamer, but we use different techniques.