基于多分辨率数据源镶嵌的大规模地形实时绘制算法

针对不同分辨率的测量地形数据源,提出了镶嵌四叉树模型,用以实现对多分辨率数据源的镶嵌,以及与细节层次(LOD)算法的融合.设计了基于此模型的批LOD算法,给出了相关公式,并设计了一种从CPU到GPU的渐进LOD数据传输方法.分析了镶嵌四叉树的场景浏览模式,设计了基于此模型的双向两级外存数据调度算法,通过水平、高度两个方向的预测和两级数据预取实现数据页的动态更新,实现了三维地形场景的快速构建和实时浏览.实验表明,该算法能够快速处理大规模多分辨率数据源并且能够充分发挥CPU、GPU与I/O的效率,从而在有限环境下进行快速实时绘制.     

基于GPU的快速Sobel边缘检测算法

传统的Soble边缘检测算法的优化和实现都是针对常用处理器(CPU、DSP和FPGA等)提出的,难以应用在图像处理器(GPU)上.本文提出了一种基于NVIDIA公司CUDA架构图形处理器(GPU)的快速Sobel边缘检测算法.快速算法根据GPU的并行结构和硬件特点,采用了纹理存储技术、多点访问技术和对称计算技术三种加速技术,优化了数据存储结构,提高了数据访问效率,降低了算法复杂度.实验结果表明,快速算法充分利用了GPU的并行处理能力,在处理4 096x4 096分辨力的8位灰度图像时速度可达190 fps,是基于CPU实现的122倍.     

微震监测区域的实时仿真建模方法

针对因建模的三维数据量巨大导致传统Open GL固定管线对三维地形渲染难以满足实时性需求这一问题,提出利用GPU可编程图形管线来进行渲染,实现区域的可视化实时显示。建模过程中首先使用基于分形理论的随机中点位移法产生地形高程数据,然后利用三角面元连接地形高程散点生成三维曲面,最后通过GLSL着色语言对GPU进行编程实现对地形的渲染。该方法建模过程与Open GL固定管线渲染效率进行对比,结果表明:利用GPU可编程图形管线对400万的三维地形网格数据进行渲染仅用时82.92 ms,效率远高于Open GL固定管线的渲染,能够满足实时渲染的需要。     

基于CUDA的点匹配合成算法

纹理合成在计算机动画制作中具有重要地位。为克服传统串行点匹配纹理合成算法效率低下的缺陷，提出一种基于计算统一设备架构（CUDA）的并行合成算法。通过合理安排CPU和GPU之间的数据传输，用GPU进行繁琐耗时的计算，明显地提高了算法效率。     

A high-speed wideband spectrometer system based on CUDA-GPU

针对射电信号观测的需求,设计并实现了一种基于统一计算设备架构(CUDA)和图形显示卡(GPU)的宽带高速频谱分析系统.该系统通过运用库利-图基(Cooley-Tukey)快速傅立叶变换算法与谱分析算法实现实时宽带高速频谱分析.系统的关键部分在于通过CUDA来完成运用线程合并算法对数据在CPU与GPU之间传递时的转换,并使用并行流水算法在总线中共享多核GPU来降低实时运算时间.该系统主要为500m口径射电望远镜工程的高分辨率微波巡视项目而设计,实测中满足目标需求,并可应用在射电信号观测或类似的高速密集数据运算中.     

基于柔性控制点的三维数据拼接方法

针对大型零件全局测量中的数据拼接问题,提出一种基于柔性控制点的三维数据拼接方法。本文详细介绍了基于机器视觉的阶梯式三维数据拼接原理及实验测量过程,通过投影柔性控制点的方式避免了粘贴标志点的繁琐过程,提高了测量效率。同时采用标准尺和壁板对本文提出的方法进行了验证,实验结果表明该方法有效能够满足大型零件的现场测量要求。     

基于GPU和CPU协同处理实现的Canopy算法探索

提出一种基于GPU(图形处理器)和CPU协同处理实现来提高聚类算法Canopy的计算效率的优化方案。利用GPU高效的并行性和灵活的可编程性等特点,将Canopy聚类算法中比较耗时的距离计算及与阈值T1,T2的比较步骤交由GPU处理,算法其余步骤仍由CPU处理,理论上提高算法速度。     

基于并行处理技术的谷物粒型快速测量算法

谷物粒型是决定谷粒品质和产量的重要参数之一。传统人工测量粒型的方法耗时、工作量大、主观性强。本文首先介绍一种基于线阵列采集技术和工业输送技术的谷物粒型自动测量系统。为提高系统测量效率,文章中应用了图形处理器(GPU)并行处理技术,在统一计算设备架构(CUDA)下对测量算法进行优化。实验结果表明,基于GPU的并行加速算法,能有效提高测量效率,当图像中谷粒数近2000颗时,优化后的算法速度为中央处理器(CPU)下算法运行速度的400多倍,且随着采集图像中谷粒数的增多,优化测量算法的加速效果更显著。     

面向GPU的循环合并

针对现有的将C或Fortran程序映射到通用图形处理单元(GPU)的自动转换工具主要关注将单个循环生成一个独立的GPU内核,从而阻碍了对循环间数据重用的利用的问题,提出一种新的面向GPU的循环合并的代码变换方法,该方法通过循环分块(strip mining)和冗余计算等手段达到消除迭代间数据依赖的目的,并可充分利用GPU片上的共享内存进行线程间数据交换,从而将此类程序高效地映射到GPU上.通过典型程序在GPU上的实验表明,该新方法由于能够减少对全局内存的访问,带来了最多高达1.96倍的加速比.     

基于GPU流计算模式的非凸体碰撞检测算法的研究

针对虚拟坐标测量系统中非凸物体间的碰撞检测问题,将非凸体分解为三角形面片,利用可编程图形处理单元(GPU)的流计算优势,将分离轴检测算法映射到图形硬件的片断着色器中,以计算三角形间的相交情况.结果表明,该算法在处理流数据时具有良好的实时性和稳定性.     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

We associate a variety of innovations with the term ＂Industry 4.0＂. The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Roman iron and steel: A review

ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Brainstorming for ISO Strategy 2016-2020

正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from