基于均值场理论和马尔可夫场的运动目标分割算法

研究了基于均值场理论和马尔可夫场的运动目标分割方法.该算法先对帧差图像进行简单的前背景划分,再采用均值场理论(MFT),建立马尔可夫随机场(MRF)模型,构造系统相应的能量函数.然后通过求取最大后验估计(MRF-MAP),即求最小能量函数,得出标记场,提取运动目标.实验结果证明:该算法能够很好地消除噪声,对运动目标分割具有较好的分割效果.     

利用组合马尔可夫模型的非监督图像分割方法

提出了一种基于边缘辅助的组合马尔可夫随机场模型(E-CMRF),并应用于非监督图像分割.在传统的马尔可夫标号场(MRF)基础上引入边缘二值随机场,二者相互作用构成组合随机场.该模型使用期望最大(EM)算法对待分割图像完成参数估计,并运用动态能量权值提高收敛速度.最后根据贝叶斯定理将图像分割问题转化为最大后验概率的求取,运用改进的Metropolis采样算法求得最大后验概率解.实验结果证明,该分割方法不需要人工给出先验信息,在具备抗噪性等特点的同时提高了分割精度.     

用于图像分割的局部区域能量最小化算法

针对点对马尔可夫随机场(Pairwise MRF)模型中像素成对交互的结构不能充分描述图像丰富的局部统计特征问题,在研究Pairwise MRF模型基础上,提出了一种基于局部区域能量最小化的图像分割算法.该算法先利用图像局部区域信息构造局部区域能量模型,建立了一种局部交互的区域马尔可夫随机场分割模型,然后采用无环置信传播(LBP)算法对MRF全局能量进行优化.优化过程中,对局部区域能量进行收敛并按照MAP准则估计局部区域标号,通过LBP算法把局部区域信息传递到邻域区域中去.实验结果表明,所提出的新算法较标准LBP算法具有更好的分割结果,并有效地抑制了图像噪声信号和纹理信号对分割结果的干扰和影响.     

基于MRF分层高斯混合模型的脑MR图分割

脑部磁共振(MR)图像由于偏移场和噪声存在灰度不均的特点.针对传统高斯混合模型应用于MR图像分割中存在噪声和异常值敏感等问题,提出一种基于马尔可夫随机场(MRF)的分层高斯混合模型分割算法.将传统的高斯混合模型进行分层处理,使用高斯混合模型替代其中的高斯分布;针对图像像素点构建MRF,更新分层高斯混合模型的先验概率;根...     

基于HMRF的半监督中智聚类算法

针对中智C-均值聚类算法抗噪能力弱的问题,提出基于隐马尔科夫随机场的半监督中智聚类分割算法.利用隐马尔科夫随机场模型的先验信息描述图像像素邻域关系,将其与隶属度相结合作为监督因子,嵌入现有中智聚类并构造半监督中智聚类目标函数;将欧式空间样本通过非线性变换用核函数映射至高维特征空间,增强图像的抗干扰能力;最后采用最优化方法获得隐马尔科夫随机场的半监督核空间中智聚类分割的迭代表达式.对灰度图像添加高斯和椒盐噪声进行分割测试,以验证算法性能.测试结果表明:所建立的分割算法相比基于隐马尔科夫随机场的模糊C-均值聚类等分割算法的抗噪性能有了显著提高.     

一种融合分层信息熵的MRF视频运动前景分割算法

针对视频图像中相邻像素的相关性对前景分割的影响问题,提出了一种以熵图像为纽带的分层马尔可夫随机场(MRF)视频运动前景分割算法.通过图像像素层和信息层构建自适应像素模型和动态光滑模型,增强了视频图像中邻域像素的空间一致性和时间连续性.然后在马尔可夫模型的框架下,采用多环置信度传播算法求解最大后验概率估计,提高视频运动前景分割的质量.实验结果表明该方法能够在不同的视频图像序列条件下完成对运动前景的有效分割.     

一种多层次语义视频对象分割算法

提出一种基于高斯马尔可夫随机场及规则化图划分的多层次语义视频对象分割算法,其主要特点是将视频序列帧中对象的分割看成是“内容树”结构中复合结点的形成过程.首先使用高斯-马尔可夫模型来进行视频帧内的最优标记场标定,然后引入规则化图划分准则进行过分割区域的合并,得到具有语义意义的视频对象.实验表明,本分割算法具有较高的准确性,误差的均值为11.375%,标准方差为0.94%.     

一种基于去除干扰基团Markov随机场的SAR图像分割算法

研究了马尔科夫随机场模型与图像的关系.利用条件迭代模型算法逐点更新图像标记,并结合区域生长思想,提出了一种基于去除干扰基团Markov随机场的SAR图像分割方法.数值试验通过与传统Markov分割算法从分割时间、迭代次数和收敛能量进行对比分析,结果表明,该方法具有更高的分割正确率,分割目标边界更清晰平滑,分割效果也更好.     

基于时空联合的水下运动目标检测方法

提出了一种基于时空联合的运动目标检测算法,考虑到四阶累计量对于噪声具有较好的抑制作用,利用帧差的四阶累计量来提取运动区域(运动模板),与传统基于背景噪声方差的阈值确定方法不同,采用单帧图像上的有效带宽作为阈值,从而消除诸如水草、海洋生物等引起的背景纹理缓慢变化.为了得到准确的分割对象,引入马尔可夫随机场,结合区域的时空属性,把对象分割问题转化为求取区域最小能量问题,对水下噪声起到了较好的抑制作用.实验结果表明该算法能够有效地检测出具有精确边缘的水下运动目标.     

基于马尔可夫随机场的遥感图像分割和描述

讨论了基于马尔可夫随机场的遥感图像分割．根据卫星遥感图像的特点,建立了相应的基于马尔可夫随机场的图像分割模型．由此将图像分割问题转化成图像标记问题, 并进一步转化成求图像的最大后验概率估计的问题． 本文引进了一种基于博弈理论的决定性退火算法, 可以用该算法对图像进行标记, 该算法收敛于局部最大, 在实验中取得了很好的效果．     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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