Graph‐Theory Approach to Eigenvalue Problem of Large Space Structures

The dynamic analysis and control system design of large space structures involve the solution of the large‐dimensional generalized matrix eigenvalue problem. The computational effort involved is proportional to the third power of the dimension of the matrices involved. To minimize the computational time a graph‐theory approach to reduce a matrix to lower‐ordered submatrices is proposed. The matrix‐reduction algorithm uses the Boolean matrices corresponding to the original numerical matrices and, thus, the computational effort to reduce the original matrix is nominal. The computational savings directly depend upon the number of submatrices into which the original matrix is reduced. A free‐free square plate is considered as an example to illustrate the technique. In this example a matrix of 16th order is reduced to three scalars corresponding to three rigid‐body modes, and three matrices of order three and one matrix of order four.     

基于图形化编程语言LabVIEW的虚拟仪器开发

本文介绍了虚拟仪器的概念，组成特征和图形化编程语言LabVIEW，并用LabVIEW开发了位移测试和系统静态精度测试系统。     

图形处理器片段处理单元的设计与实现

针对图形处理器三维引擎中对图形的后期处理需求,实现片段写入帧缓冲区前的测试、混合、逻辑操作、累积、清除和屏蔽等关键功能。分析并提取了OpenGL核心库中的片段处理相关函数,确定了片段处理单元要实现的功能;合理安排多个片段处理功能的执行顺序,设计了基于流水线的片段处理单元结构;采用Verilog HDL对电路进行描述,采用 Cadence NC-Verilog 仿真工具进行虚拟验证,采用 Xilinx 的 ISE 工具进行综合,并在 Xilinx Virtex6 XC6VLX760 FPGA上进行原型验证,电路工作频率可以达到180 MHz,测试功能正确。在SMIC 65 nm CMOS工艺下,采用Synopsys Design-Compiler对设计进行综合,电路工作频率达到300 MHz,满足设计需求。     

Adaptive block size for dense QR factorization in hybrid CPU–GPU systems via statistical modeling

QR factorization is a computational kernel of scientific computing. How can the latest computer be used to accelerate this task? We investigate this topic by proposing a dense QR factorization algorithm with adaptive block sizes on a hybrid system that contains a central processing unit (CPU) and a graphic processing unit (GPU). To maximize the use of CPU and GPU, we develop an adaptive scheme that chooses block size at each iteration. The decision is based on statistical surrogate models of performance and an online monitor, which avoids unexpected occasional performance drops. We modify the highly optimized CPU–GPU based QR factorization in MAGMA to implement the proposed schemes. Numerical results suggest that our approaches are efficient and can lead to near-optimal block sizes. The proposed algorithm can be extended to other one-sided factorizations, such as LU and Cholesky factorizations.     

Advancements in the design and validation of an air pollution integrated assessment model for Spain

This paper describes the design and application of the Atmospheric Evaluation and Research Integrated model for Spain (AERIS). Currently, AERIS can provide concentration profiles of NO₂, O₃, SO₂, NH₃, PM, as a response to emission variations of relevant sectors in Spain. Results are calculated using transfer matrices based on an air quality modelling system (AQMS) composed by the WRF (meteorology), SMOKE (emissions) and CMAQ (atmospheric-chemical processes) models. The AERIS outputs were statistically tested against the conventional AQMS and observations, revealing a good agreement in both cases. At the moment, integrated assessment in AERIS focuses only on the link between emissions and concentrations. The quantification of deposition, impacts (health, ecosystems) and costs will be introduced in the future. In conclusion, the main asset of AERIS is its accuracy in predicting air quality outcomes for different scenarios through a simple yet robust modelling framework, avoiding complex programming and long computing times.     

基于CUDA的并行粒子群优化算法研究及实现

应用图形处理器(GPU)来加速粒子群优化(PSO)算法并行计算时,为突出其加速性能,经常有文献以恶化CPU端PSO算法性能为代价。为了科学比较GPU-PSO算法和CPU-PSO算法的性能,提出用"有效加速比"作为算法的性能指标。文中给出的评价方法不需要CPU和GPU端粒子数相同,将GPU并行算法与最优CPU串行算法的性能作比较,以加速收敛到目标精度为准则,在统一计算设备架构(CUDA)下对多个基准测试函数进行了数值仿真实验。结果表明,在GPU上大幅增加粒子数能够加速PSO算法收敛到目标精度,与CPU-PSO相比,获得了10倍以上的"有效加速比"。     

“里特罗”风格与平面设计

“里特罗”风格的设计流派的特点是强调历史风格的复古和重构,是对欧洲20世纪上半叶的平面设计风格的复兴。“里特罗”风格既是对这个时期的风格特点的偏爱和认可,又是对当时的现代主义和国际主义中的沉闷、刻板、乏味以及过分理性的反对。由于这个风格是对20世纪20年代至30年代流行的某些平面风格的复兴及演绎,对于今天的平面设计依然有着重要的影响。     

剪纸艺术的魅力

传统剪纸艺术是民俗文化的形象载体之一,维系藿整个民间艺术基本源头的文化根基,也是现代平面设计取之不尽、用之不竭的灵感宝藏。而当代艺术设计中的体积感、空间感对立体剪纸又有着引领式的启发作用,二者相互借鉴,便剪纸艺术更加多元化。如果单纯的将民俗剪纸艺术与二维平面进行对比和研究,可以更好更有创意的弘扬传统剪纸艺术,也可以将平面设计创作的更具视觉传达性、民族性、世界性。当代的立体剪纸即传承了传统剪纸的精髓又借鉴三维设计中立体构成的各个元素和形式,开拓了剪纸艺术的新天地。     

关于AUTO CAD在图形图像教学领域的多元结合应用

AUTO CAD是一款交互式计算机辅助设计以及绘图的软件,在传统的教学中很多学生都认为这款软件的学习十分困难,所以很难提起学习兴趣,还有一些学生学习了后面的知识就会忘记前面的知识,这就使得教学质量与效率很难提升。为此,教师应积极主动探索有效的教学方式,激发学生的ATUO CAD软件的学习兴趣,提升教学和学习的质量。本文就探讨ATUO CAD在图形图像教学领域的多元结合应用。