基于自适应评价函数的独立成分分析算法

简要介绍独立成分分析（ICA）及其模型，然后在极大似然估计的框架下，基于两类参数模型--Gaussian混合密度模型和Pearson系统模型，研究了具有对称分布（包括超高斯分布与亚高斯分布）和非对称分布源混合信号的盲分离问题，给出了一种有效的基于灵活评价函数的ICA新算法，该算法在一定意义上实现了对源信号概率分布的真正全“盲”。与原有的ICA算法相比，该算法具有更广泛应用范围。模拟实验验证了算法的有效性。     

Schwarzschild黑洞Dirac场的统计熵

利用改进的brick-wall模型,给出了Schwarzschild黑洞Dirac场的熵.结果表明,当调整截断参数,使4r2M＝1/90π时,则熵为SF＝7AH/8,或可表示为SF＝7πM.     

从几个次序统计量出发的二参数Weibull分布的参数估计

从两个或三个次序统计量出发，讨论了二参数Weibull分布的参数估计问题，在实际数据的缺失、删失、截尾等情况下，为可靠性试验的数据处理提供了一种有效的估计方法．     

Intermediate view synthesis from stereoscopic images

1.INTRODUCTION Stereoscopicimagesandvideohavebeensuccessfully exploitedinmedicine,remoteguidance,computer aideddesignandentertainmentforaboutadecade[1].Inrecentyears,withthedevelopmentof3Dtech niques,somenewfunctionsaredemandedforsuch systems.Oneofthedesirablefunctionsisthe“con tinuouslook around”-visualizationof3Ddataonthe screenfromdifferentviewingangles.Theviewer shouldbeabletoacquirecorrespondingviewswhen hemoveshishead.Thisisequivalenttopositioninga stereocamerainthe3Dsceneinaccor…     

Radiation embryology

Summary Prenatal development, characterized by intensive cell proliferation, cell differentiation and cell migration, shows a high radiosensitivity. Therefore, radiation exposure of embryos and fetuses is of great concern for radiological protection and human health. Irradiation during gestation can cause death, growth disorders, malformations, functional impairment and malignant diseases in childhood. These effects are strongly dependent on the developmental stage at exposure and on the radiation dose. The first trimester of pregnancy is regarded as the period with the highest risk for malformation and cancer induction. The developing nervous system shows a special susceptibility to ionizing radiation over a long period and is therefore of great significance for risk estimation. Knowledge about radiation effects on prenatal development has been derived from animal experimentation and from the exposure of human embryos. There is evidence that doses between 1 and 10 cGy may lead to developmental anomalies and that the radiation response can be modified by additional factors.     

Harmonic Retrieval Embedded in Hybrid Colored Noise: a Novel Pisarenko Method Based on Cross-high-order Cumulant

Spectral estimation method is an effective method in the case of parameter estimation of sinusoid signal in noises.It always applies cross-spectral estimation theory and high-order self-spectral estimation methods up to now.Yule-Walker equation based on cross-fourth-order cumulant is developed and Pisarenko method is provided in this paper.Simulation results show that the method is effective to retrieve sinusoid signal frequencies from hybrid colored noises and has good performance.     

载流导体径向电场的数值估算

应用经典电磁理论,推出了载有恒定电流导体内部存在径向电场的表达式,并对导体内部的径向电场及表面电势进行了估算.结果表明,导体内径向电场是微小的.计算出电流强度为200A,导线截面为1cm2的铜导线,其内部径向电场强度约为1.13×10-6V/m.     

基于小波变换的LMSV模型波动长记忆性估计与检验

将小波引入到LMSV模型波动长记忆性的估计与检验中，提出了基于小波变换的LMSV模型波动长记忆性的伪极大似然估计法和波动长记忆性的检验方法，用不同参数值和样本容量的数据进行了模拟实验．又用该方法对上海和深圳证券交易所综合指数收益序列的LMSV模型的波动长记忆性进行了检验和估计，结果表明该方法是有效且可行的．     

冷轧TA7合金板材织构的完整ODF分析

依取向空间的等体积划分原理,将传统的六方晶系材料特征非对称子空间(等角法)予以改造。并按等面积投影法对 ODF 图进行重建。按此法对实测的冷轧 TA7 合金板材完整ODF 施行织构分析。结果表明,织构分析与原等角法的完全等效;此方法能清晰地建立起反极图与 ODF 图之间的关系。等面积投影法的采用使织构定量简便、易行。     

NEUMANN SERIES SOLUTION TO A NEUTRON TRANSPORT EQUATION OF SLAB GEOMETRY

This paper deals with the solution to an energy, dependent stationary neutrontransport equation of slab geometry. In L~p space, the equation is converted into an equiva-lent integral equation. By the study of the corresponding integral operator and its spectralradius, results of Neumann series solution are obtained, and an easy-verified condition thatthe transport equation has a nonnegative solution is given.