查询词典 reconstruction

In the first part, depending on three or more images, the main research work are listed as follows:(1) using SVD decomposition to realize projective reconstruction;(2) realizing camera self-calibration by solving Kruppa's equation;(3) recovering Euclidean reconstruction from projective reconstruction. Depending on only two images, the main researches are:(1) making out infinite plane homography matrix by using scene structure information, then recovering affine reconstruction from projective reconstruction;(2) making out the absolute conic images by using scene structure information, and then recovering Euclidean reconstruction from projective reconstruction.

在第一部分中，针对三幅及三幅以上的图像，主要研究：①利用矩阵奇异值分解实现射影重构，②通过求解Kruppa方程实现摄像机自标定，③由射影重构恢复欧氏重构；针对只有两幅图像的情况，主要研究：①利用场景结构信息求解无穷远平面的单应矩阵，由射影重构恢复仿射重构，②利用场景结构信息求解绝对二次曲线的像，由仿射重构恢复欧氏重构。

3D reconstruction is one of the most challenging problems in computer vision. This project uses CAD model to increase the accuracy,robustness and speed of 3D reconstruction and five different works are conducted: 1 research on space curve 3D reconstruction method based on high curvature point nad turning point; 2 free-form curve 3D reconstruction based on B-spline and BURBS; 3 Active surface affine reconstruction based on single frame; 4 Matching and reconstruction of 3D sparse points; Data fitting method based on the iteration of nearest point.

三维重建是计算机视觉中公认的难题，本项目使用CAD模型来提高三维重建的精度、稳健性和速度的思路，围绕着空间曲线和曲面的三维重建和匹配开展了以下五个方面的研究：1）基于高曲率点和拐点分割的空间曲线三维重建方法研究；2）基于B样条和NURBS表示的空间自由曲线三维重建方法研究；3）基于单帧图像的有源曲面仿射重建；4）三维离散数据的匹配与重建；5）基于迭代最近点的数据拟合方法。

Nowadays, in the low electron dose condition, the information about 3-4〓 can be recorded on the cryoEM micrograph, and the high-resolution reconstruction using the cryoEM has reached 6. 5-8〓 levels. The reconstruction can reveal the protein α helical and recognise β fold secondary structure. Secondly, it is due to the development in 3D reconstruction method, which can be more efficient to determine the orientation and center parameters. The last but not least, it is also owning to the rapid development in computer science and information technology. Such as, some computational task, which previously must be executed by using super-computer, now can be carried out by personal computer, and at the same time, the network speed and band width of data bus and input/output equipment have increased several times. In addition, the improvement of the high quality graphic displaying is available. All these provide strong support for cryoEM high-resolution reconstruction study.

目前，在低电子剂量的情况下，冷冻电镜照片可以记录到3-4 〓的信息，使用冷冻电子显微镜进行高分辨三维重构工作，已经获得6.5-8〓高分辨率水平的结果，可以分辨出蛋白质的α螺旋、识别出蛋白质的β折叠等蛋白质二级结构；其次是，三维重构算法效能的不断提高，使得对二十面体取向和中心参数计算的可靠性大大提高；再次是，由于计算机和信息技术迅猛发展，例如，以往需要使用大型计算机的计算任务已经可以被一般的个人电脑完成，网络速度、数据总线和硬盘等I／O设备的带宽成倍增长，以及图像显示能力的提高都为冷冻电子显微镜高分辨三维重构技术提供了强有力的支持。

Bezier and NURBS are chosen as the fundamental method to achieve surface reconstruction on the basis of fundamental theory of sculpture surface reconstruction. Then the fitting method of Bezier and NURBS surface reconstruction is given after the reconstruction algorism is discussed.

作者研究了复杂曲面重建的基本理论，选择Bézier和NURBS作为曲面重建的基本方法，同时对曲面重建的算法进行研究，给出Bézier和NURBS曲面拟合的不同方法，并对求交、拼接和光顺等方法进行了深入研究。

As requests for aid continued to come in from around the world, he forecast the Bank would provide up to $100bn in loans over the next three years through its International Bank for Reconstruction and Development arm.

随着全球范围内的援助要求继续增多，他预计，世行将在未来3年内，通过旗下的国际复兴开发银行(International Bank for Reconstruction and Development)，提供至多1000亿美元贷款。

China received more than $9.9 billion in IDA credits between 1981 and 1999, when it ceased being a client. Since 1999, the country has received market-rate loans through the World Bank's International Bank for Reconstruction and Development.

从1981年至1999年中国一直在接受IDA援助，共计获得了99亿美元的援助资金。1999年起中国不再接受该项目的帮助，而是开始通过世界银行旗下的国际复兴和开发银行(International Bank for Reconstruction and Development)以市场利率获得贷款。

The reconstruction problem is ill-posed, so two optimal criterions, the least module and the smoothness criterion base on Tikhonov regularization technique, are introduced into reconstruction algorithm. Many regularization parameters choice strategies are investigated, and the TPA(Two—Parameter Algorithm) strategy which is based on the Morozov discrepancy principles, is implemented in two regularization reconstruction algorithms.Numerical experiment results show that the nonnegative and smoothness constraint condition can overcome the difficulty of iteration semiconvergent, preconditioned technique can improve convergence rate and reconstruction accuracy, smoothness regularization criterion can meliorate ill-posed problem of reconstruction and enhance iteration stability, and the TPA is an effective strategy of regularization parameters choice.

数值试验表明：在共轭梯度法中引入非负约束和光滑约束改善了迭代的"半收敛"性，非负约束保证了解的非负性，光滑约束抑制了重建解的振荡现象，约束算法的重建精度与无约束算法相比大幅度提高；在约束共轭梯度重建算法中引入预优技术，可以加快算法的收敛速度，提高迭代的稳定性和重建精度；引入光滑准则的正则化技术可以有效改善图像重建问题的不适定性，加快迭代的收敛速度，提高迭代的稳定性和图像重建质量，计算正则参数的TPA算法在闪光照相图像重建中是有效的。

The reconstruction problem is ill-posed, so two optimal criterions, the least module and the smoothness criterion base on Tikhonov regularization technique, are introduced into reconstruction algorithm. Many regularization parameters choice strategies are investigated, and the TPA(Two—Parameter Algorithm) strategy which is based on the Morozov discrepancy principles, is implemented in two regularization reconstruction algorithms.Numerical experiment results show that the nonnegative and smoothness constraint condition can overcome the difficulty of iteration semiconvergent, preconditioned technique can improve convergence rate and reconstruction accuracy, smoothness regularization criterion can meliorate ill-posed problem of reconstruction and enhance iteration stability, and the TPA is an effective strategy of regularization parameters choice.

数值试验表明：在共轭梯度法中引入非负约束和光滑约束改善了迭代的&半收敛&性，非负约束保证了解的非负性，光滑约束抑制了重建解的振荡现象，约束算法的重建精度与无约束算法相比大幅度提高；在约束共轭梯度重建算法中引入预优技术，可以加快算法的收敛速度，提高迭代的稳定性和重建精度；引入光滑准则的正则化技术可以有效改善图像重建问题的不适定性，加快迭代的收敛速度，提高迭代的稳定性和图像重建质量，计算正则参数的TPA算法在闪光照相图像重建中是有效的。

As the beam further propagation, self-reconstruction of the Bessel beam generated. The divergence of the self-reconstruction beam causes the beam intensity decreasing and the bright spot size increasing as the beam propagating.

当光束继续传播，贝塞尔光发生自重建(Self-reconstruction)，但重建的Bessel光将会发散，光强随着传播距离增大而迅速下降，且中心亮斑尺寸也迅速增大。

Objective To investigate the clinical value of helical CT threedimensional reconstruction in diagnosis of thoraciclumbar burst fractures.

摘 要］目的：探讨螺旋CT三维重建(ThreeDimensional Reconstruction ，3D)技术在胸腰椎爆裂骨折中的诊断及临床应用价值。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。