Disparity field and depth map coding for multiview 3D image generation

In the present paper techniques are examined for the coding of the depth map and disparity fields for stereo or multiview image communication applications. It is assumed that both the left and right channels of the multiview image sequence are coded using block- or object-based methods. A dynamic programming algorithm is used to estimate a disparity field between each stereo image pair. Depth is then estimated and occlusions are optionally detected, based on the estimated disparity fields. Spatial interpolation techniques are examined based on the disparity/depth information and the detection of occluded regions using either stereoscopic or trinocular camera configurations. It is seen that the presence of a third camera at the transmitter site improves the estimation of disparities, the detection of occlusions and the accuracy of the resulting spatial interpolation at the receiver. Various disparity field and depth map coding techniques are then proposed and evaluated, with emphasis given to the quality of the resulting intermediate images at the receiver site. Block-based and wireframe modeling techniques are examined for the coding of isolated depth or disparity map information. Further, 2D and 3D motion compensation techniques are evaluated for the coding of sequences of depth or disparity maps. The motion fields needed may be available as a byproduct of block-based or object-based coding of the intensity images. Experimental results are given for the evaluation of the performance of the proposed coding and spatial interpolation methods.     

空间工程辅助设计GIS系统的研究与实践

探讨GIS技术在空间工程辅助设计(例如电力、电信管线工程)方面的应用.在系统分析空间工程设计的 逻辑过程和工程辅助设计系统的发展与需求的基础上,对GIS技术在空间工程辅助设计中应用的优势及工程辅助 设计GIS系统的结构、功能和特点以及系统基本设计思路进行了探讨，指出GIS技术的引入一方面提高了空间工 程辅助设计的效率和水平，同时使空间工程辅助设计成为同时具有规划和设计功能的系统。     

基于空间矩的灰度边缘亚像元度量精度分析

灰度图像中边缘定位受采样密度限制，亚像元精度度量方法在需要高精度的应用中受到重视，要想知识到底需要多高的分辨率才能达到定精度指标，就有必要分析特征定位方法的最坏情况的精度，文中用分析和实验的方法给出了基于空间矩的边缘定位方法，对于边缘点，边缘直线以及直边缘区域的最坏情况定位精度分析。分析和讨论的结果不但可以用来确定已知形状位置估计的最大误差，而且还可用于对准的形状几何参数，以获得较高的精度。     

电子政务建设若干经验与问题探讨

介绍世界电子政务的发展状况,在总结各国电子政务发展经验和特点的基础上,指出我国要建设优质、高效的电子政务的关键,是要树立转变观念、统一规划、分步实施的建设理念.     

空间RSCR四杆机构图解综合法的研究

根据空间RSCR四杆机构出现特殊位置的几何特征,运用旋转变换把空间问题转换为平面问题,对实现两特殊位置运动的空间RSCR曲柄摇杆机构的图解综合法进行了探讨。     

低空间频率银盐明胶全息图的浮雕特性研究及其应用

通过实验研究表明，对低空间频率的振幅型银盐全息图形表面已形成浮雕，经漂白，浮雕深度成倍加深；浮雕深度随空间频率而变化，并且可用不同曝光量进行调制。选择适当条件，可降低零级光强，提高全息图的一级衍射效率。     

A finite element parametric study on the mechanical properties of J-shaped steel hysteresis devices

The present paper discusses the mechanical properties of J-shaped steel hysteresis devices, abbreviated to “J-dampers”, interposed between the upper structure of a spatial structure and its substructure. The mechanical properties of a J-damper, which are characterized by its key geometrical and material parameters, are evaluated through parametric analyses using an in-house Finite Element program. The hysteresis behavior of a J-damper is also modeled by a bi-linear elasto-plastic hysteresis model with the strain-hardening effect. Its elastic stiffness, yield strength and dimensionless hardening ratio, which are expressed as functions of the parameters, are formulated on the basis of mathematical models and the results of parametric studies. Finally, some remarks relevant to the application of the proposed hysteresis model are made for the design of the J-damper.     

A noncontact NDE method using a laser generated focused-Lamb wave with enhanced defect-detection ability and spatial resolution

The laser generation method of a focused Lamb wave is expected to have high defect-detection abilities and spatial resolution, with the added advantage of noncontact testing. In this method, the laser beam is illuminated on the surface of an object through an arrayed arc slit. The energy of the generated Lamb wave is then concentrated at a focus of an arc. This focusing effect improves the NDE (nondestructive evaluation) performance, which is dependent on the geometries of an arrayed arc slit. In this paper, the relationships between the parameters determining the slit geometry and the focusing effect of the generated Lamb wave was investigated using a parametric study, and appropriate values of the parameters were obtained to maximize the focusing ability. In order to validate the performance of this method, an NDE system was constructed and experiments were performed to detect through-hole defects in a plate. The results showed that the proposed system could clearly detect defects as small as 0.3 mm in diameter, while the conventional line array method failed to detect defects smaller than 1 mm in diameter. Moreover, this method showed possible detection of defects much smaller than 0.3 mm, and great improvements in the spatial resolution as compared with the line array method.     

Characterization of temporal response, spectral responsivity and its spatial uniformity in photoconductive diamond detectors

Three photoconductive diamond detectors with highly oriented diamond (HOD) films fabricated by the same process were characterized with respect to temporal response, spectral responsivity and its spatial uniformity over the wavelength range from 190 to 250 nm. Temporal measurements showed a drift in the baseline, suggesting the presence of deep level carrier traps. The responsivity of specimen No. 2 was more than twice those of the other two specimens, but it showed an unpredictable current fluctuation. It was found that the spatial uniformities of all the specimens were too low for radiometric purposes. A prominent peak, thought to be due to photoemission, was found in the responsivity spatial distribution of specimen No. 3 under a negative applied voltage.