心脏核磁共振图像左心室底层组织分割方法

提出了一种基于局部灰度聚类(LIC)模型和分水岭算法的心脏核磁共振成像(MRI)图像左心室底层组织分割方法.首先,使用LIC模型对图像进行初步分割,提取出图像中的组织和器官;然后,使用分水岭算法弥补粘连的不同组织或器官之间缺失的边界,将其分开,人工选取种子点进行区域生长初步提取左心室;最后,利用左心室形状特征的先验知识判断提取的左心室中是否包含主动脉,若包含则去除主动脉,得到精确的左心室分割结果.实验结果表明,该方法能有效去除心脏MRI图像上左心室底层存在的弱边界和边缘泄露的影响,得到准确的左心室底层组织分割结果.     

基于K-means算法分割遥感图像的阈值确定方法研究

当前遥感图像分割中阈值确定方法忽略了前景和背景内在的联系,导致过分割和轮廓模糊,造成整体性能低下。为此,提出一种新型基于K-means算法分割遥感图像的阈值确定方法,通过K-means算法对遥感图像进行分割,利用最大类间方差方法得到分割遥感图像的初始阈值,依据该阈值将遥感图像划分成两类,求出两类的均值,将其作为K-means聚类算法的两个初始聚类中心,通过K-means聚类方法逐次迭代,不断更新聚类中心,直至得到聚类准则函数,从而求出遥感图像的最佳分割阈值。实验结果表明,采用所提方法确定遥感图像分割中的阈值,不仅效率高,而且整体性能优越;将得到的阈值应用于遥感图像分割中,能够使目标和背景被有效分离,且分离后目标部分轮廓比较清晰。     

基于FCM和标记分水岭的粘连岩石颗粒图像分割

模糊C均值算法可利用图像的多种特征值进行准确的图像分割,但不能分割粘连物体;传统的分水岭分割算法能够获得准确的物体边缘轮廓,但容易造成过分割.为了解决这个问题,提出基于FCM和标记分水岭的粘连图像分割.该方法首先对原始彩色图像中值滤波后进行基于LUV颜色空间的FCM聚类;对聚类后的图像用形态学方法去杂质、空洞填充后进行距离变换;然后根据距离变换图像找出局部最大值,得到种子图像;最后对距离变换图像进行基于标记的分水岭分割,得到最终的分割图像.该方法对粘连岩石颗粒图像进行分割,取得了较好的实验效果.     

基于扫描线种子填充的二值图像聚类算法

提出了一种基于扫描线种子填充的二值图像快速聚类算法 .该算法步骤为 :对二值图像进行扫描 ,如果检测到了目标点 ,则将该点作为新的聚类的种子 ,将该种子扩展到整个目标区域 ,形成一个包含目标区域的聚类 .该算法的特点为 :只需一次扫描即可动态生成所有聚类 ,聚类总数动态生成 ,每一时刻只有一个聚类被处理 ,可提前进行一些后续处理 ,算法描述简单 ,易于编程实现 .     

基于云理论的图像分割新方法

针对区域生长算法的种子点初始化和生长准则问题,提出了一种基于云模型和区域生长的图像分割方法.该方法首先利用云变换对图像进行变换生成云模型,然后利用云模型的Ex作为区域生长的种子点,以云的极大判定法则作为区域生长准则进行区域生长,获得最终的分割结果.这种分割方法不但克服了区域生长法种子点和生长准则选取不当而产生过分割和欠分割的不足,而且很大地提高了云模型分割图片的速度,实验结果证明,该方法可以准确地分割出目标,是一种有效的图像分割方法.     

基于形态学运算的种子轮廓自动获取方法

为解决传统手工初始化种子轮廓影响肝脏分割算法稳定性的问题,提出了一种基于形态学运算的自动种子轮廓获取方法.根据序列CT图像中肝脏的灰度特性和结构特性,利用线性灰度变换、阈值滤波、中值滤波及对比度增强对肝脏CT图像进行预处理操作,进而通过形态学腐蚀运算快速准确获取肝脏自动分割需要的种子轮廓.实验结果表明,该自动种子轮廓获取方法可以快速、准确地定位出肝内种子轮廓,保证种子轮廓不会因操作人员不同而发生位置变化.     

基于动态加权模糊核聚类算法的医学图像分割新方法

采用动态加权的模糊核聚类算法对CT医学图像进行分割.该算法对模糊核聚类算法中的特征向量进行动态加权,以自动削弱噪声特征向量在聚类中的作用,这样可以减小噪声对图像分割的干扰.实验结果表明,采用该种新算法对CT图像分割后,可以获得更清晰的分割图像.     

结合图像显著与灰度不一致性的目标自动提取

该文将图像过分割技术与图像显著性相结合,提出了一种基于图像显著性与灰度不一致性的目标自动提取方法。该方法可在没有任何人工干预的情况下准确地提取出图像的感兴趣目标。首先,通过像素不一致性因子和邻域不一致性因子确定出图像的不一致性种子点和一致性种子点;然后,使用等价类划分的方法对两类种子点分别进行生长,得到不同的等价类,合并残余类之后得到图像的初分割块;最后由初分割结果结合显著性检测算法提取出完整的感兴趣目标。考虑到像素的局部邻域信息,首次将图像的底层特征——像素的灰度不一致性应用于图像分割,并以此为基础进行目标提取。实验表明,该方法能够有效地实现显著目标的自动提取。     

基于轮廓波变换的模糊聚类图像分割

提出基于轮廓波变换的模糊聚类图像分割算法,从变换域的角度提高传统聚类算法的抗噪声能力.首先用轮廓波变换对含噪声图像消嗓,然后再进行聚类图像分割.实验结果表明:新算法能够获得较好的图像分割效果和质量.     

基于帧差和Otsu的红外行人分割算法

针对红外图像中行人与环境对比度较低,直接进行分割易产生误分割问题,提出一种基于帧差和Otsu的红外行人分割算法.首先选取红外视频序列中时间间隔较短的2帧图像求其帧差图像,对帧差图像采用Otsu分割得到运动目标的部分区域;然后对基准帧也采用Otsu方法分割,并将帧差图像分割结果与基准帧分割结果相乘,得到目标区域的种子像素;最后在基准帧分割图像上,通过连通性判断得到最终的行人分割区域.实验结果表明,该算法很好地克服了环境带来的干扰,鲁棒性强,能有效实现红外行人目标的分割.     

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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