测量工件三维曲面的工业视觉测量系统

基于近场摄影测量技术提出一种测量工件三维面形的工业视觉系统．介绍了系统测量原理、系统构成和定标、工件三维面形测量实验及实验结果,详细讨论了影响测量精度的各种因素．这种方法尤其适合于大尺寸工件复杂面形的检测     

测量工件三维曲面的工业视觉测量系统

基于近场摄影测量技术提出一种测量工件三维面形的工业视觉系统。介绍了系统测量原理,系统构成和定标,工件三维面形测量实验及实验结果,详细讨论了影响测量精度的各种因素,这种方法尤其合适于大尺寸工件复杂面形的检测。     

回转式激光线扫描测量仪

提出一种基于线结构光的回转式视觉测量系统,首先介绍系统的组成和工作原理,建立了线结构光测头的数学模型,并用该系统对测头进行标定;然后确定转台的回转中心,实现了将测头二维测量值向被测物体三维坐标的转换;最后,给出了实际测量结果,此系统能一次性完整测量任意工件的外表面,测量精度优于0．07mm。     

基于双目视觉的相位测量偏折术

现代制造业对镜面、类镜面进行面形测量需求强烈,详细介绍了相位测量偏折术的原理,提出了基于双目视觉的相位测量偏折术系统数据获取方法和计算流程,采用插值积分技术进行面形重建.通过计算机模拟方法,针对口径为420 mm的凹面镜进行了双探测器数据获取,梯度计算和面形重建.计算结果表明,采用双目视觉的相位测量偏折术系统和插值积分技术进行面形重建,在一定噪声情况下具有较高的重建精度,可用于自由曲面的反射表面测量.     

新型液晶编码光栅立体视觉传感器

物体形面视觉测量中，为了获取更多且准确的图像对应信息，特别是立体像对的匹配信息，需要通过视觉传感器对测量图像进行调制．该文介绍了研究设计的新型液晶编码光栅形面测量视觉传感器，采用东福EDMl288液晶模块和光学投影照明系统，并且通过计算机通讯控制液晶编码，无机械运动，测量速度快，可得到大量三维测量点信息．实验验证，这种传感器可靠性高，可操作性强，且具有较高测量精度，三维测量点拟合平面的平均误差为0．103mm，可以实现物体的形面测量．     

多路法激光跟踪干涉测量系统的研究

叙述了测量系统的工作原理，给出了测量一个运动物体三维坐标的计算方法，指出测量系统要进行自标定和测量，运动物体的“不同动点数”应大于9，简要分析了测量系统的组成，各自的工作原理，测量系统的误差来源与误差传递，最后通过实验验证了测量的可行性，得出测量速度为0．5m/s，测量不确定度为0.062mm。对于提高系统精度和可靠性提供了可靠的方向和有益的建议。     

TM65 m射电望远镜面形微波全息测量

微波全息法是一种用于大型天线面形测量和调整的有效手段,本文先简单介绍了微波全息法的技术发展情况,接着针对天马65 m射电望远镜,仿真了面形误差和副面偏移算法.然后给出了在最佳俯仰角53°上,65 m面板实测和调整情况,通过多次调整,65 m面形精度达到了0.28 mm,重复测量误差0.13 mm.最后在俯仰角45°–60°上采用Ka波段对天线效率进行了测量,比较分析了主动面面形调整前后的性能改善情况,在Ka波段上效率由原来的37%改善到约56%,与理论预测相符.     

视觉测量中基于距离相对约束的优化算法

提出了一种新的基于距离相对约束的优化算法,该算法通过附加视场边缘距离约束条件较好地实现了对透镜畸变的纠正,提高了空间面形测量的精度.利用视场边缘相对控制点间空间距离固定以及像点坐标值残余误差平方和最小构建新的目标函数,并计算相应的法方程,经过数次迭代后可获得测量系统的方位参数和测量点的空间坐标,完成空间物体3D面形测量.对距离控制场的测量实验证明,该算法特别适用于大尺寸面形的测量,在3 m×4 m×1 m的测量视场内,根据该算法建立的视觉测量系统其最大测量偏差小于0.5mm,可满足大尺寸面形的测量要求.     

非接触光学测头在金属强反射表面测量中的应用

强反射表面的高精度金属件和光学件的表面轮廓测量，是形貌检测领域的一个难点．文中提出了一种用于逆向工程领域的自由曲面非接触测量系统，其由三坐标测量机和主动式双目视觉形貌测头组成．通过摄像机标定了视觉测头，利用光学偏振技术消除了金属表面强反射光对测量的干扰．对扫描路径进行了规划，并根据金属表面加工纹理方向，选择采样策略．通过对量块表面的测量，验证了使用非接触方法测量金属强反射表面的可行性．研制测头的精度达到了0．05mm．     

基于结构光图像法的三维曲面重构技术

提出了一种基于编码结构光的新型三维重构技术的原理和系统的标定方法．这种技术以条纹变形作为物体三维信息的加载和传递工具，以CCD摄像机作为图像获取器件，通过计算机软件处理，对颜色信息进行分析、解码，通过已标定的系统计算来获取物体的三维面形数据．对该系统进行了理论分析，并以石膏像模型为对象进行了具体实验，得到了较满意的结果．     

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).     

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.     

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.