基于多尺度的掌纹辨识算法

为了解决局部二值模式(Local Binary Pattern,LBP)不能有效的提取掌纹不同尺度的特征,提出一种对曲线有很好描述、多尺度的第二代曲波变换(Curvelet)与LBP选择性结合的多尺度掌纹辨识算法。首先将原始掌纹图像进行Curvelet变换,获得不同尺度的掌纹图像;其次对得到的掌纹图像选择性使用LBP提取特征;最后采用卡方距离对不同的掌纹进行分类。通过对PolyU掌纹图像库中具有不同光照、平移、旋转的图像进行验证,证明了此算法对光照、旋转、平移都有很好的效果,且识别率高于LBP算法与其他传统算法,达到99.20%,证明了此算法的有效性,同时,特征提取与匹配时间为139.4×10-3s,满足实时性要求。     

功能磁共振时间序列图像快速配准方法研究

提出了一种非迭代分别检测时间序列图像间旋转、平移运动的方法．该方法基于傅立叶频谱的相位相关特性，解决了迭代配准算法中的旋转与平移耦合问题．通过精心选择参考图像，采用基于递归数字滤波的三次B样条插值方法，实现了功能磁共振序列图像的快速配准，配准精度达到了亚像素级。     

基于二维Gabor的掌纹图像预处理研究

掌纹识别属于相对较新的一种生物特征识别技术,是利用人手掌上丰富的纹理特征来进行身份识别。掌纹图像的质量是影响掌纹识别性能的关键,因此,由掌纹的特点入手,对掌纹图像采用基于形态学方法进行感兴趣区域(ROI)的分割,为了防止由于采集时手放置位置的旋转或偏移导致的掌纹图像的差异,通过中值滤波、二值化、膨胀腐蚀等操作确定了特殊角点,再利用角点连线确定旋转角度,来旋转掌纹图像。然后对掌纹图像感兴趣的区域采取小波阈值法来去除噪声。最后结合Gabor滤波器的方向性,采用基于二维Gabor滤波器对掌纹纹线的特征进行提取。为了验证所提出的掌纹图像预处理方法的有效性,在PolyU掌纹图像库上进行实验并取得了较好的实验效果。     

基于标记点的图像配准

针对图像在采集过程中会受到物体表面反射及噪声等影响所造成的图像特征提取效果不佳及用整幅图像的像素点进行计算导致的运算量大、精度低等问题,提出了一种基于标记点的配准方法.该方法利用链码的概念,首先对图像进行预处理,提取出标记点质心坐标并根据提取出的质心坐标形成链码;其次,将质心链码做一阶差分形成差分链码,通过差分链码的旋转和平移的不变性得到配准点对对链码进行配准;最后,通过点对坐标计算旋转角度和平移参数.实验结果表明提出的方法对于图像平移和旋转情况下配准精度高,有较强的抗噪声性能并能达到很好的精度.     

基于边缘扩展相位相关的图像拼接算法

针对图像拼接算法中计算量大的问题,提出了一种基于边缘扩展相位相关的图像拼接算法。该算法采用迭代阈值分割法对图像进行边缘检测,并对检测出的边缘进行扩展相位相关计算,得出图像间的平移、旋转和尺度变化。利用这些参数拼接图像,用渐进渐出的方法实现拼接图像的融合。实验证明,该算法能够简化计算,并有效地实现图像的拼接。     

用于墙地砖缺陷检测的自动精确图像配准方法

将规则图案墙地砖的精确配准方法用于墙地砖表面缺陷检测，通过对图像进行预处理及边缘检测，找出墙地砖的四条边及左上角，首先对参考砖和待测砖之间的位移和旋转角度进行初步估计，对待测墙地砖进行平移，使其左上角与参考墙地砖的左上角对准并旋转完成初步配准，然后，用互相关法寻找更精确的平移参数进行精确配准，这样可以在像素与像素之间进行直接比较以进行缺陷检测，实验结果证明该方法能有效检测出像孔穴、裂纹等一般缺陷。     

低定位精度条件下掌纹图像识别

提出了一种多层次相位相关掌纹识别(HPCPR)算法.先采用改进的结合相关值位置和大小的方法在整体上匹配和对齐掌纹图像,再用分块的加权相位相关法(WPC)精确匹配对齐后的掌纹图像,实现了低定位精度条件下掌纹图像的有效识别.算法综合使用掌纹图像的整体和局部特征,且能更快地对齐待匹配图像.与传统基于相位相关的识别方法相比,该算法既提高了识别的精度,又在识别的效率上获得明显改进.在PolyU掌纹库上的测试结果验证了算法的良好效果.     

抗旋转的数字图像水印算法

 提出1种在载体图像发生旋转后仍可以正确检测的数字水印算法.该方法将水印序列排列成圆环状,嵌入在图像频谱的中频区域,利用Fourier变换的旋转性质,将图像的旋转转化为水印序列的平移,并利用随机序列的互协方差函数的峰值位置检测出平移尺度,从而正确提取水印.     

基于MEMS陀螺仪的电子稳像算法

针对电子稳像运动估计过程中,特征匹配方法存在匹配误差以及3D运动估计方法计算复杂等问题,提出一种基于MEMS(Micro-electro-mechanical system)陀螺仪的电子稳像算法。首先,利用MEMS陀螺仪估计相机旋转抖动量,利用尺度不变特征变换方法SIFT(Scale-invariant feature transform)估计相机平移抖动量;其次,利用滤波技术对平移及旋转运动矢量平滑滤波处理;然后,对视频序列的高频率旋转及平移抖动量进行运动补偿;最后,利用图像拼接技术去除运动补偿后的图像边缘"黑边"。实验结果表明,该算法对于相邻图像帧的抖动补偿准确性较高,处理效果较好,减少了系统的计算复杂度。     

结合学习特征的图像矩视觉伺服方法

针对平面图像特征选择,提出一种结合学习特征的改进图像矩视觉伺服方法,以解决不变图像矩特征存在的交互矩阵奇异问题并获得更优的运动特性.该方法首先基于不变矩特征具有的TRS(2D平移、2D旋转及尺度变化)不变特性,利用非线性支持向量机回归算法,对不变矩特征与摄像机X轴、Y轴转角的关系进行分别学习建模;然后利用两个模型的估计值(即学习特征)作为针对X轴旋转及Y轴旋转运动的图像特征,其交互矩阵具有完全解耦及线性特性,且对于任意平面目标不存在奇异问题;进而结合目标图像重心点坐标和面积的归一化特征及图像方向角特征,实现摄像机在任务空间的平移及旋转六自由度控制;最后通过仿真验证了文中方法的有效性.     

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…     

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。     

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     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.     

An improved R-tree based on childnode''s probability

R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).     

Integrating GIS Web services based on mediating architecture

The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.     

Tracking data management using topology of moving object database system for moving object constrained trajectory in LBS application

Advances in wireless technologies and positioning technologies and spread of wireless devices, an interest in LBS (Location Based Service) is arising. To provide location based service, tracking data should have been stored in moving object database management system (called MODBMS) with proper policies and managed efficiently. So the methods which acquire the location information at regular time intervals then, store and manage have been studied. In this paper, we suggest tracking data management techniques using topology that is corresponding to the moving path of moving object. In our techniques, we update the MODBMS when moving object arrived at a street intersection or a curved road which is represented as the node in topology and predict the location at past and future with attribute of topology and linear function. In this technique, location data that are corresponding to the node in topology are stored, thus reduce the number of update and amount of data. Also in case predicting the location,because topology are used as well as existing location information, accuracy for prediction is increased than applying linear function or spline function.