基于ICA的时间序列聚类方法及其在股票数据分析中的应用

时间序列聚类分析是时间序列数据挖掘中的重要任务之一，通常由于时间序列数据的特殊结构，导致一般的聚类算法不能直接应用于时间序列数据。本文提出了一种基于独立成分分析与改进^一均值算法相结合的时间序列聚类算法，该算法首先利用独立成分分析对时间序列数据进行特征提取，然后利用改进￡．均值聚类算法完成对时间序列特征数据的聚类分析，从而得到了一种新的基于特征的时间序列聚类方法。为了验证该方法的有效性和可行性，将其应用于实际的股票时间序列数据聚类分析中，取得了较好的数值结果。     

基于AFS拓扑和FCM的模糊聚类分析

聚类分析是数据挖掘的一个重要研究课题，模糊聚类是聚类分析的一个有效手段。本文在分析AFS方法和FCM算法的基础上，设计了一个基于AFS拓扑和FCM的模糊聚类算法，进行iris数据的聚类实验证明它聚类结果优于传统的FCM聚类算法，具有很好的推广性和实际应用价值。     

群落有序样本的一种聚类分析方法

目前，适用于群落聚类分析中有序样本的聚类方法主要是“最优分割法”。本文提出了一种新的适用于群落有序样本的聚类方法，该法较最优分割法计算简便。     

一种扩展聚类分析方法

本文定义了聚类中心以及点到聚类中心的距离，提出了一种平面点集的动态聚类分析方法。     

一种扩展的动态聚类分析方法

本文定义了聚类中心以及点到聚类中心的距离，提出了一种平面点集的动态聚类分析方法。     

基于ICA的时间序列聚类方法及其股票数据分析中的应用

时间序列聚类分析是时间序列数据挖掘中的重要任务之一,通常由于时间序列数据的特殊结构,导致一般的聚类算法不能直接应用于时间序列数据.本文提出了一种基于独立成分分析与改进K-均值算法相结合的时间序列聚类算法,该算法首先利用独立成分分析对时间序列数据进行特征提取,然后利用改进K-均值聚类算法完成对时间序列特征数据的聚类分析,从而得到了一种新的基于特征的时间序列聚类方法.为了验证该方法的有效性和可行性,将其应用于实际的股票时间序列数据聚类分析中,取得了较好的数值结果.     

分支分类问题的随机优化解法

分支分类问题可归纳为聚类分析问题。通常的分支分类方法均属于聚合法，这些方法只能保证得到的局部最优解。本文应用划分方法进行聚类。根据随机优化理论搜索得到最优解，实验结果表明该方法是正确和可行的。     

基于Hausdorff距离的区间数据的系统聚类分析

基于Hausdorff距离用于定义两个紧集之间距离的考虑,将区间数视为一个紧集,定义了区间数之间的距离,并研究了区间向量的距离,从而得到聚类分析中两个样品间的距离。进一步定义了两个类之间的Hausdorff距离。为消除量纲对聚类结果的影响,研究了区间数据的标准化。基于此,给出了区间数据系统聚类算法。采用随机模拟的方法,对文中方法进行有效性评价,结论表明,Hausdorff距离法的聚类有效性在所有设计的实验条件下都要优于传统的欧式距离法。最后,基于符号数据分析的思想构造区间数据,给出了对多种动物群体按其身高、体重等生理特征进行聚类分析的算例。     

上证30指数二届成份股的聚类分析

本文采用聚类分析法技术，研究和分析了上证３０指数。论文在特尔菲技术基础上选择了十项聚类分析指标。主要研究结论为：上证３０指数二届成份股可以分为五类，论文并对这五类成份股的特征进行了分析     

我国各地农民家庭消费结构分析

本文运用聚类分析和主成分分析等统计方法，对我国３０个省、自治区、直辖市的农民家庭的消费结构进行聚类和分析，找出影响我国农民家庭消费结构的因素，为经济研究提供科学依据．     

Anisotropy in the destruction of compact bone material

Conclusions 1. The nature of the destruction of compact bone material upon short-term static compressive and tensile stresses, as well as upon impact bending, is a function of the anistropy of the structure on the osteon level.2. The compact bone material of femoral bones of the age range studied is destroyed by shear for the types of stresses indicated.3. The nature of the destruction of samples of compact bone material for the stresses studied may be generalized for tubular bones.Kurgan Scientific-Research Institute of Experimental and Clinical Orthopedics and Traumatology. Translated from Mekhanika Polimerov, No. 2, pp. 319–324, March–April, 1978.     

Study of posterolateral lumbar arthrodesis by means of a finite element model

Posterolateral lumbar arthrodesis consists in the fixation of the lumbar vertebrae pedicles by means of bars and screws. It is indicated in all those cases in which instability exists previous to the surgery, or in those other cases in which the instability has been caused by the need of bone resections that put the articulations structures in danger.The pedicle fixation of the lumbar arthrodesis is a great advance in the lumbar surgery. It contributes to achieve a stable and biologic fusion. The aim of the present research is the analysis of the contact problem that exists between the screw and the bone as one of the key points to control in order to achieve a good future stability of the arthrodesed spine.In order to achieve such aim, a Finite Elements Model (FEM) of the spine was performed. Such a model was obtained using a computer vision technique that creates 3D bodies using computed tomographies of the sacrum and vertebrae L4 and L5. Not only the bone bodies have been modeled, but also the intervertebral discs that act as the joints of the bones. In order to obtain a complete simulation of the lumbar region the titanium screws and bars have been modeled too.The study of the influence of the contact between bone and screw in the biomechanical behavior of the lumbar column has been studied applying several load conditions simulating different kinds of typical movements of the column. Finally, the stresses on the different elements of the lumbar structure and the relative movements between bone and screw as well as the conclusions of this research are also expounded.     

A spatial decay in the linear theory of microstretch piezoelectricity

The electromagnetic theory of microstretch elasticity is an adequate tool to describe the behavior of porous bodies, animal bones and solids with deformable microstructures. In this paper we study the linear theory of microstretch piezoelectricity. First, we establish a spatial decay estimate. Then, we obtain an upper bound for the amplitude term.     

Studies on Bone Remodeling Theory Based on Microcracks Using Finite Element Computations

The investigation of the microcrack theory supports the research work of understanding the microstructural behaviour of physiological loaded bones. Microcracks in cortical bone are assumed to have a stimulatory effect on osteocytes – the sensor cells for the bone remodeling process. In this contribution an approch to simulate microcrack initiation and propagation inside a 3D anisotropic and inhomogenious FEA model of cortical bone tissue will be shown. The numerical formulations are based on computational continuum damage mechanics. (© 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

神经元的形态分类和识别——2010年全国研究生数学建模竞赛C题论文

根据神经元的空间几何特征参数,研究神经元的空间形态分类方法,将神经元根据几何形态分类识别.首次提出利用模糊C均值算法(FCM)建立了模糊聚类分析模型,对所给的神经元样本进行了分类,这一模型用来对神经元进行分类比较合理,且计算结果准确.同时,还利用相关分析原理分析了不同动物神经系统中同一类神经元的形态特征有着很高的相似度.     

Optimum selection of the dental implant diameter and length in the posterior mandible with poor bone quality – A 3D finite element analysis

This study aimed to evaluate continuous and simultaneous variations of dental implant diameter and length, and to identify their relatively optimal ranges in the posterior mandible under biomechanical consideration. A 3D finite element model of a posterior mandibular segment with dental implant was created. Implant diameter ranged from 3.0 to 5.0 mm, and implant length ranged from 6.0 to 16.0 mm. The results showed that under axial load, the maximum Von Mises stresses in cortical and cancellous bones decreased by 76.53% and 72.93% respectively, with the increasing of implant diameter and length; and under buccolingual load, by 83.97% and 84.93%, respectively. Under both loads, the maximum displacements of implant-abutment complex decreased by 58.09% and 75.53%, respectively. The results indicate that in the posterior mandible, implant diameter plays more significant roles than length in reducing cortical bone stress and enhancing implant stability under both loads. Meanwhile, implant length is more effective than diameter in reducing cancellous bone stress under both loads. Moreover, biomechanically, implant diameter exceeding 4.0 mm and implant length exceeding 12.0 mm is a relatively optimal combination for a screwed implant in the posterior mandible with poor bone quality.     

A Porous Media Model for the Description of Adaptive Bone Remodelling

Bones are strong and lightweight structures, which mainly consist of extracellular bone matrix. The bone remodelling is a process of resorption followed by replacement of the bone matrix with small changes in shape, which allow the bones to adapt according to the local loading situation. In the context of the Theory of Porous Media (TPM), a consistent model of bone tissue is introduced, which is able to describe the local accretion and reduction of the extracellular bone matrix. To this end, the bone is treated as an aggregate of two immiscible constituents. In this biphasic macroscopic model, the aggregate consists of the extracellular bone matrix and cells summarised to a solid phase and an interstitial fluid phase comprising nutrients, metabolites and bone precursors. The addition and removal of bone matrix is described by a mass exchange between the constituents, which depends upon the local strain of the material. Additionally, the growth energy is introduced as a non-mechanical quantity, which measures the average amount of chemical energy available for cell metabolism [1, 2], and thus, controls the growth process. The presented numerical example illustrates the fundamental effects of bone remodelling under varying boundary conditions. (© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Age-induced changes in the deformation capacity of the compact bone tissue of the human tibia when subjected to torsion

Changes taking place in the initial shear moduli, maximum shear strains, and maximum specific energies of shear deformation of the compact bone tissue of the human tibia with increasing age are considered. The orthotropic character of the deformation characteristics of this tissue when subjected to torsion are examined in relation to age; also examined is the inhomogeneity of their distribution with respect to the cross-sectional zones of the diaphysis. The results emphasize the importance of preserving mechanical compatibility when transplanting bones.