一种基于图像轮廓信息的新视点图像生成算法

对于摄像机任意运动采集的序列图像，提出了一种基于轮廓对应的新视点目标图像生成算法．在此算法中，首先检测并提取图像中的轮廓边缘，将边缘分解为直线段，根据直线段间的相对位置关系实现不同图像间直线段的匹配，从而实现整幅图像问匹配．采集的参考图像首先转化到与视点连线平行的平面（称做校正图像）．然后，通过对校正图像匹配点线性插值生成对应于新视点的校正图像；最后将该生成的校正图像变换至最终位置，从而实现新视点图像生成．实验证明，该算法可应用于任何种类的图像合成，所生成图像可以获得清晰的边缘，图像质量较高．     

鹰眼系统运动目标特征参数精确提取算法

鹰眼系统在赛场上可对球类运动轨迹进行跟踪和记录并在辅助裁判对边界球的判罚中起着重要作用,然而由于网球提取过程存在目标小、飞行速度快、光照变化、广告字符以及其他的运动物体影响的问题,网球特征参数提取精准度有待进一步提升。针对这些问题,提出了一种鹰眼系统运动目标特征参数精确提取算法,该算法利用网球色彩一致性较好的特点,根据彩色训练获取网球色调的范围,在HSV色彩空间中对网球图像进行颜色分割,减少背景图像的干扰,采用帧间差分与混合高斯模型融合算法对网球图像进一步分割获取运动目标,对分割后的二值图像使用Sobel算子提取边缘信息减少后续目标圆检测的运算量提高效率,采用Hough圆变换检测轮廓边缘信息完成网球圆心和半径参数的精确提取。实验结果表明,该特征参数提取算法拟合准确率高、相对偏差小,具有一定的实际应用价值。     

基于纹理特征的主动轮廓模型图像分割

现有的图像分割方法在轮廓提取过程中大多利用基于图像灰度信息的能量函数,没有考虑目标图像纹理特征信息,不能准确描述待分割纹理图像的边缘轮廓。针对该问题,给出了一种利用主动轮廓模型的方法,将图像纹理信息加入到主动轮廓的能量函数中,构造一种新的外部能量函数,求取函数的最优解,由此获得目标图像轮廓。实验表明,该方法能有效解决复杂纹理图像边缘描述不准确的问题,获得较完整准确的目标轮廓。     

基于时空特性的运动目标检测算法研究

采用时序分割虽然能够检测到运动目标区域,却不能准确地提取出目标轮廓．本文提出了基于时空特性的运动目标检测算法．由背景减法检测到运动目标的位置、形状、大小信息,然后采用以彩色梯度为外部能量的活动轮廓（snake）算法获得准确的运动对象轮廓．实验证明,本算法能够很好地提取出运动目标．     

基于改进式主动轮廓模型的序列超声心动图左室短轴轮廓跟踪

提出了一种序列超声心动图左室短轴轮廓跟踪方法.运用改进式主动轮廓模型算法并结合帧间图像配准原则逐帧进行轮廓提取,从而实现序列超声心动图左室短轴轮廓跟踪.该方法的突出特点是在复杂的心脏运动条件下解决左室短轴运动的序列图像轮廓跟踪问题.从实验结果可以看出,该方法能够比较准确地跟踪序列超声心动图左室短轴轮廓.     

基于小波变换及GVF模型的SAR图像轮廓提取算法

给出一种基于小波变换及GVF模型的SAR图像轮廓提取算法.首先,对SAR图像进行预处理,分割出可能的目标片;其次,利用小波多尺度分析滤波和基于梯度矢量流的主动轮廓模型进行边缘点的连接,得到真实轮廓.实验结果表明该方法能较好地提取SAR图像的轮廓.     

基于分形理论的焊缝信息提取

在基于机器视觉信息的焊缝跟踪系统中，受焊接条件的影响，所拍图像经常存在许多干扰信号，严重地影响了准确焊缝边缘位置信息的获得．针对这一问题，文中利用基于分形理论的边缘提取算法对有干扰图像中的焊缝边缘位置进行了提取．该算法利用各向同性的分数布朗随机场模型对焊缝图像进行分析，通过适当选取无标度区域求出了像素点及其邻域的分数维，并据此来区分焊缝边缘区域．文中还用该算法对自然光及弧光(混合气体保护焊)干扰条件下的焊缝图像进行了处理，结果表明，在较强的干扰条件下，此算法也能够将焊缝边缘位置信息准确提取出来，使焊缝中心位置误差不超过0．3mm．     

一种改进的变分水平集车辆检测技术

针对传统运动目标检测算法存在适应性差、对噪声较敏感等缺点,提出一种基于变分水平集快速提取边缘模糊运动目标的方法。该算法利用主动轮廓模型进行边缘检测约束,并结合变分水平集方法进行二次演化获得准确的图像分割。实验证明,该方法能够快速准确的分割运动目标,对于复杂环境有较好的适应性和鲁棒性。     

一种改进的变分水平集车辆检测技术

针对传统运动目标检测算法存在适应性差、对噪声较敏感等缺点,提出一种基于变分水平集快速提取边缘模糊运动目标的方法。该算法利用主动轮廓模型进行边缘检测约束,并结合变分水平集方法进行二次演化获得准确的图像分割。实验证明,该方法能够快速准确的分割运动目标,对于复杂环境有较好的适应性和鲁棒性。     

基于Prewitt算子的计算机数字图像边缘检测改进算法

为了使提取的图像边缘的结构定位精确，并产生连续的精细边缘，同时能滤除边缘信息中的噪声干扰，提出了一种以Prewitt算子为基础，应用区域分割和骨架提取的改进算法，实现了图像边缘信息的提取，能消除图像中的噪声，产生精细的边缘。实验证日月，该算法能有效地消除噪声，准确地检测图像中的目标边缘，且能较好地保持目标边缘的连通性。     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

Perspherical Approaches for Electrons in Atoms and Charged Excitons in Quantum Wells

Instead of following Fock’s expansion,we solve the Schrodinger equation for some quantum mechanical manybody systems such as electrons in atoms and charged excitons in quantum wells in a similar way in hyperspherical coordinates by expanding the wave functions into orthonormal complete basis sets of the hyperspherical hannonics(HHs)of hyperangles and generalized Laguerre polynomials(GLPs)of the hyperradius.This leads the equation to     

Advances in broadband wireless communications under high-mobility scenarios

Future mobile communication systems aim at providing very high data transmission rates, even in high-mobility scenarios such as high-speed wheel-track trains, maglev trains, highway vehicles, airplanes, guided missiles or spacecraft. A particularly important commercial application is the strong and increasing worldwide demand for high- speed broadband wireless communications （up to 574.8 km/ h test speeds or 380 km/h commercial speeds） in railways, providing data, voice and video services for applications such as onboard entertainment services to passengers, train control, train dispatch, train sensor status handling and sur- veillance. In such high-mobility scenarios, there are a number of communication challenges, including fast hand- over, location updating, high-speed channel modeling, estimation and equalization, anti-Doppler spreading tech- niques, fast power control, and dedicated network architec- ture. Because signal transmission in very high-speed scenarios will inevitably experience serious deterioration, it is imperative to develop key broadband mobile communi- cation techniques for such high-speed vehicles.     

Wuhan University Journal of Natural Sciences TOTAL CONTENTS

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海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Scale-based spatial data model for GIS

Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer-based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer-based model. Furthermore, in Web-Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale-based model. In this model we represent maps in three levels: scale-view, block, and spatial object, and organize the maps in a set of map layers, named Scale-View, which associates some given scales.Lastly, a prototype Web-Based GIS using the proposed spatial data representation is described briefly.     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to