基于IP-SAN的电视节目非线性制作网络的设计与建设

本文介绍了扬州广播电视总台基于IP-SAN的电视节目非线性制作网络的设计与建设.重点介绍了网络组建方案对比与选型.提出了系统安全性方面的一些设计方案.对以后其他单位采用IP-SAN网络搭建中等规模的非线性制作网有一定的借鉴作用.     

Voxelization and fabrication of freeform models

We present a volume graphics system for the generation of freeform models and synthesis of complex objects. A unique non-uniform rational B-spline (NURBS) volume representation and its voxelization algorithm are proposed. The forward difference technique is employed to speed up the voxelization process while the desired topological connectivity is preserved. For synthesis of our models and other three-dimensional objects, such as computed tomography images, voxel-based cutting tools are developed for the AutoCAD user interface. Volume rendering is applied to visualize the intermediate and final models. An isosurface is then extracted over the synthesized model and exported to a rapid prototyping machine as an STL file for fabrication. The approach taken in this system has been proven robust and efficient in modelling and fabrication of complex freeform models.     

地球物理高性能计算的新选择：GPU计算技术

随着地球物理对高性能计算需求的不断提升，集群系统节点规模不断提高，一方面大大提高了系统建设、运行、维护、管理及应用软件开发的复杂性，另一方面在提高系统总体性能方面也受到越来越大的制约。随着微电子技术的发展，GPU计算技术与可重构计算技术，将有可能替代集群计算技术成为高性能计算的主流技术。充分利用GPU并行处理能力，可以将GPU作为计算加速器为基于CPU的通用计算平台提供高性能的科学计算能力补充，这样可以在现有通用计算平台的基础上实现高性价比的高性能计算解决方案。GPU计算平台上的应用软件开发比可重构计算平台上的应用软件开发要容易得多，这一点使得GPU计算技术可以更早地广泛应用于地球物理领域。GPU计算产品已达到很高的性能，相应的软件开发环境也已推出，对于GPU计算平台应用软件开发技术的研究将使得GPU计算技术在不远的将来广泛地应用于地球物理计算中。     

Curvature-based stroke rendering

This paper describes an algorithm that renders lines that have various thicknesses and have sharp tapered ends. This algorithm does not require any special information on each local point of a line. The thickness is determined by curvature and lengths from both ends. Therefore the algorithm is applicable in a variety of line rendering situations, such as 3D rendering engines for high quality cel-animation-like effects, reuse of geometrical data designed by CAD for advertising purposes, edge enhancement in a photo retouching process with edge detection methods and so on. In addition, using the generated varying thicknesses, we have developed algorithms for shading and embossing effects.     

Color rendering properties of light continuously modulated by an electrochromic switchable device

Every chromogenic switchable window gives rise to considerable change of spectral power distribution of the light crossing trough. The filtered light continuously changes during charging/discharging of the device, seen as its coloration/discoloration. As this process occurs continuously, it causes continuous change of colors on an illuminated multicolored scene. The ability of an electrochromic (EC) switchable unit to modulate daylight and different artificial lights passing through it is studied here. The color rendering properties of such a variable light are evaluated. The range of the effect and its consequences on the color of a scene can be adequately described by the change in chroma and hue angle during the modulation of light. These effects were evaluated by different light sources shining through the same EC unit. © 2009 Wiley Periodicals, Inc. Col Res Appl, 34, 321–329, 2009     

Tunable and high-color-rendering white light emissions in full visible spectral range in Ag-aggregates/Sm3+ co-doped germanate glass fluorophors

To achieve a tunable and high-color-rendering white light emission in full visible spectral range, the Ag-aggregates/Sm³⁺ co-doped germanate glass fluorophors were prepared by a melt-quenching method. Under the excitation of different wavelengths, the intense broadband emissions covering full visible spectral range from blue to red were gained in the germanate glasses only containing Ag-aggregates. From the optical spectral analyses, it was found that with increasing the excitation wavelengths, the emission peak position exhibits red-shift. However, the red component in the emission spectra is still of relative lack for realizing high quality white light, therefore Sm³⁺ was introduced as co-dopant to supply the red spectral component. In this way, a series of chroma-tunable and full-color-emitting white lights with color coordinates from (0.26, 0.25) to (0.30, 0.32) were successfully realized based on adjusting the excitation wavelengths and Sm³⁺ concentration. Particularly, the color rendering index (CRI) up to 97.6 was achieved. Furthermore, the luminescence thermal stability of Ag-aggregates/Sm³⁺ co-doped germanate glass fluorophors was investigated based on the Arrhenius model, and the corresponding ΔE values for Ag aggregates and Sm³⁺ emissions were confirmed to be 0.25 and 0.19 eV, respectively. In addition, a temperature sensing model was established based on the luminescence intensity ratio of Ag-aggregates to Sm³⁺, and the thermochromatic property of Ag-aggregates/Sm³⁺ co-doped germanate glasses was also evaluated. It was found that the luminescence color coordinates of Ag-aggregates/Sm³⁺ co-doped glass fluorophors always lie in the white light region when the sample temperature increases from 301 to 693 K, thus indicating that Ag-aggregates/Sm³⁺ co-doped glass fluorophors have potential application in solid-state lighting sources as a single-component white lighting material.     

Impact of the adapted white point and the cultural background on memory color assessments

With their inherent ability of serving as an internal reference, memory colors provide a very powerful concept in the evaluation of color rendering properties of white light sources with respect to visual appreciation. Recent results for example suggest fairly good correlations between memory-based color quality metrics and the observers' general color preferences. However, due to technical limitations in the design of the underlying psychophysical experiments, they generally lack the explicit inclusion of realistic viewing and adaptation conditions, which is supposed to have a nonnegligible impact on the model prediction performance. In addition, intercultural effects might play a crucial role in the context of memory colors. For these reasons, the current article investigates the impact of both the adapted white point and the observers' cultural background on memory color assessments in order to contribute to a better understanding of these dependencies and their interactions. For this purpose, the color appearance rating results of Chinese and German observers were collected for a selection of 12 different familiar test objects assessed under two different adaptation conditions at 3200 K and 5600 K, respectively. From the statistical analysis of the experimental data, it is shown, in accordance to previous studies, that the impact of the observed intercultural deviations is likely to be of no practical importance even though significance is found. Despite considerably larger effect sizes, the same must be concluded for the two tested adaptation conditions.     

基于GPU的数学形态学运算并行加速研究

数学形态学运算是一种高度并行的运算,其计算量大而又如此广泛地应用于对实时性要求较高的诸多重要领域。为了提高数学形态学运算的速度,提出了一种基于CUDA架构的GPU并行数学形态学运算。文章详细描述了GPU硬件架构和CUDA编程模型,并给出了GPU腐蚀并行运算的详细实现过程以及编程过程中为充分利用GPU资源所需要注意的具体问题。实验结果表明,GPU并行数学形态学运算速度可达到几个数量级的提高。