23 resultados para Computer-Aided Design

em Chinese Academy of Sciences Institutional Repositories Grid Portal


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A complete set of match calculation methods for optimum sizing of PV/wind hybrid system is presented. In this method, the more accurate and practical mathematic models for characterizing PV module, wind generator and battery are adopted; combining with hourly measured meteorologic data and load data, the performance of a PV/wind hybrid system is determined on a hourly basis; by fixing the capacity of wind generators, the whole year's LPSP (loss of power supply probability) values of PV/wind hybrid systems with different capacity of PV array and battery bank are calculated, then the trade-off curve between battery bank and PV array capacity is drawn for the given LPSP value; the optimum configuration which can meet the energy demand with the minimum cost can be found by drawing a tangent to the trade-off curve with the slope representing the relationship between cost of PV module and that of the battery. According to this match calculation method, a set of match calculation programs for optimum sizing of PV/wind hybrid systems have been developed. Applying these match calculation programs to an assumed PV/wind hybrid system to be installed at Waglan island of Hong Kong, the optimum configuration and its hourly, daily, monthly and yearly performances are given. (C) 2003 Elsevier Science Ltd. All rights reserved.

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It is necessary to generate automorphism group of chemical graph in computer-aided structure eluciation. In this paper, an algorithm is developed by all-path topological symmetry algorithm to build automorphism group of chemical graph. A comparison of several topological symmetry algorithm reveals that all-path algorthm can yield correct of class of chemical graph. It lays a foundation for ESESOC system for computer-aided structure elucidation.

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在同步数据流模型(SDF)描述的嵌入式数字信号处理(DSP)系统中,计算体单一出现调度(SAS)算法对于存在反馈环和数据密集处理的应用不可解或内存优化效果很差.文中提出了将SAS和Non-SAS类型调度算法相结合的层次化的存储优化方法,定义了数据密集分量和强连通分量来描述环和数据密集处理结构,并依据数据优先消耗原则设计了启发式的Non-SAS调度算法对分量进行存储优化.该方法适用于任意SDF模型,并有良好的存储优化效果.实验结果证明了其有效性.

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目前针织服装设计领域面临着日益加剧的市场竞争,传统的基于手工设计的研发模式已不能适应当前多品种、小批量、交货期短的市场需求。传统的计算机辅助设计软件(Computer Aided Design, 简称CAD)在服装行业得到广泛应用,但效果与期望值相差较远。传统设计软件多关注于设计结果的表达与重用,对于设计过程中的计算知识重用机制缺乏有效的支持;另外这些设计软件大多基于传统的WIMP范式的菜单或命令行交互方式,不符合人们用纸笔勾画的习惯,不利于计算机操作水平普遍较低的服装行业从业人员的使用。本文拟基于知识重用的设计思想,将笔交互技术引入到传统针织服装工艺设计过程中,设计并实现一个基于知识重用的针织服装工艺快速设计系统,进而提高服装设计的效率。 论文主要研究内容包括: (1)通过分析传统针织服装工艺设计过程特点,提出了基于知识重用的针织服装工艺快速设计过程模型,并分析了该过程模型的特点,建立了系统业务流程和系统框架; (2)针对设计案例形状知识的重用,研究了形状知识的表达和提取方法,针对典型款式的针织服装设计,提出了设计轮廓图的实例化算法实现了尺寸驱动功能,提出了基于草图相似度的设计案例推荐技术,该推荐技术分别采用特征点匹配和形状匹配实现了设计案例的推荐; (3)针对设计案例计算知识的重用,研究了计算知识的表达方法,设计了面向计算知识编辑的基于手势的笔式用户界面,改进了传统Radial布局算法对计算知识进行可视化呈现,以辅助设计者对计算知识的理解和编辑; (4)在上述研究的基础上,设计并实现了一个基于知识重用的针织服装工艺快速设计系统,经过实验评估,该系统相比于传统的CAD软件能显著提高设计效率。

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本文将Smith预估技术与逆 Nyquist 阵列法结合对多时延多变量对象进行离散控制系统设计,采用这种方法设计出的控制器易用计算机实现,系统仿真结果也是令人满意的。

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根据对零件制造精度和效率的关注程度的不同,开发出了多种分层算法。在同等加工时间的情况下,根据加工精度的不同,将这些分层算法分为等层厚分层算法和适应性分层算法两类。通过对STL模型、原始CAD模型和点云数据的分析,讨论了两类分层算法的研究和发展,然后介绍了斜边分层算法和曲面分层算法等先进分层算法的原理和成果,最后讨论了快速成型分层算法的研究方向和趋势。

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测量数据的精确定位是实现复杂曲面加工检测的关键,针对测量点云数据与NURBS表示的CAD自由曲面模型匹配中求最近点计算方面存在的问题,提出了一种简单、有效的寻找最近点的方法。该方法与由测量点集评估给定曲面上的最近点的传统算法相反,采用点集曲面(point set surface,PSS)投影算法,对给定自由曲面模型上有限个点与不附加任何几何和拓扑信息的散乱点集之间进行粗匹配获得初始位置,进而以最近点迭代算法(ICP)完成测量数据定位的精确调整,达到全局及局部最优的目标。实验结果表明,采用PSS投影算法法寻找最近点不仅效率高,而且能得到全局匹配结果,可以为精匹配提供较好的计算初值,减少了ICP算法进行二次匹配时,迭代次数及执行时间并且精度得到了较大提高。

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从德鲁德理论出发,对多元共蒸法镀制的非均匀膜的折射率分布与沉积速率的关系进行了探讨;然后利用计算机辅助模拟,对德鲁德分布非均匀光学薄膜,从单周期和多周期、正变和负变、完整周期和存在半周期几个方面对其光学特性进行了系统分析.研究发现:其透射率的极小值和周期数的关系遵从周期数的三次多项式衰减规律,不同规律的德鲁德分布非均匀膜可用来设计不同功能的滤光片.

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本文简要介绍了发明问题解决理论TRIZ和机算机辅助创新软件Pro/Innovator的主要内容,建立了基于创新理论TRIZ和CAI软件的创新问题解决流程模型,作为特例建立了Pro/Innovator1.0的简化流程图,最后用软件完成了一个工程实例问题的创新设计。

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本文针对我国计算机绘制机械图领域内的现状,提出了一种易于掌握的机械图描述语言,以及一个相应的功能较强的绘图系统。该系统便于图形输入,并具有图形的平移、旋转、映射等功能,和较强的剖面域的处理能力。系统带有一个标注专用的笔写式字符库(包括汉字和专用符号)。该系统用 FORTRAN 语言写成,便于向大、中型计算机和存储容量较大的微型机移植。

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P-glycoprotein (P-gp), an ATP-binding cassette (ABC) transporter, functions as a biological barrier by extruding cytotoxic agents out of cells, resulting in an obstacle in chemotherapeutic treatment of cancer. In order to aid in the development of potential P-gp inhibitors, we constructed a quantitative structure-activity relationship (QSAR) model of flavonoids as P-gp inhibitors based on Bayesian-regularized neural network (BRNN). A dataset of 57 flavonoids collected from a literature binding to the C-terminal nucleotide-binding domain of mouse P-gp was compiled. The predictive ability of the model was assessed using a test set that was independent of the training set, which showed a standard error of prediction of 0.146 +/- 0.006 (data scaled from 0 to 1). Meanwhile, two other mathematical tools, back-propagation neural network (BPNN) and partial least squares (PLS) were also attempted to build QSAR models. The BRNN provided slightly better results for the test set compared to BPNN, but the difference was not significant according to F-statistic at p = 0.05. The PLS failed to build a reliable model in the present study. Our study indicates that the BRNN-based in silico model has good potential in facilitating the prediction of P-gp flavonoid inhibitors and might be applied in further drug design.

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针对“神光-Ⅱ”装置第九路系统主激光瞄准精度小于等于30μm和大焦斑辐照均匀性优于10%的要求,提出了靶场终端光学组件的设计结构。应用有限元法对组件关键机械元件和ICF靶室整体进行动静态分析,优化了设计参数。同时与聚焦透镜配合进行数值分析列阵透镜,确定了单元数、曲率和厚度以及单元长和宽等参数。经过实验测试,主激光瞄准精度达到28.9μm,大焦斑辐照的形状为1000μm×500μm,均匀性为12.0%。

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在分析计算机审计的特点及需求的基础上,借鉴数据仓库、OLAP、数据挖掘等技术的优势,提出了一种新型的计算机审计模型。该模型克服了传统审计软件的不足,有效地解决了面对海量数据的审计等问题,提高了审计的效率及质量。最后还对智能审计的发展作了一定的探讨。

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We investigated the effects of Ginsenoside R-e on human sperm motility in fertile and asthenozoospermic infertile individuals in vitro and the mechanism by which the Ginsenosides play their roles. The semen samples were obtained from 10 fertile volunteers and 10 asthenozoospermic infertile patients. Spermatozoa were separated by Percoll and incubated with 0, 1, 10 or 100 mu M of Ginsenoside R-e. Total sperm motility and progressive motility were measured by computer-aided sperm analyzer (CASA). Nitric oxide synthase (NOS) activity was determined by the H-3-arginine to H-3-citrulline conversion assay, and the NOS protein was examined by the Western blot analysis. The production of sperm nitric oxide (NO) was detected using the Griess reaction. The results showed that Ginsenoside R-e significantly enhanced both fertile and infertile sperm motility, NOS activity and NO production in a concentration-dependent manner. Sodium nitroprusside (SNP, 100 nM), a NO donor, mimicked the effects of Ginsenoside R-e. And pretreatment with a NOS inhibitor N-omega-Nitro-L-arginine methyl ester (L-NAME, 100 mu M) or a NO scavenger N-Acetyl-L-cysteine (LNAC, 1 mM) completely blocked the effects of Ginsenoside R-e. Data suggested that Ginsenoside R-e is beneficial to sperm motility, and that induction of NOS to increase NO production may be involved in this benefit.