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 共查询到12条相似文献,搜索用时 62 毫秒
1.
Technical illustration based on 3D CSG models   总被引:2,自引:0,他引:2  
Non-photorealistic rendering (NPR) is effective at conveying information, more expressive or more beautiful than its photorealistic counterparts (Lans-down and Schofield, 1995). Technical illustration is a special subset of NPR since both of them share human perception as common driving force. NPR aims at rendering 3D objects to convey engineering informa-tion, and is very popular in engineering drawing. Many researchers had investigated its application for technical illustration. Gooch e…  相似文献   

2.
Electrical conductivity in biomolecules and other large polymeric systems has become an important topic of current research. Schlag et al.(2000a; 2000b) demonstrated that charge migration in proteins is highly efficient although the mechanistic origin is still debated and largely unknown even though various models have been proposed by Weinkauf et al.(1995; 1996; 1997). According to them, the charge transfer between amino acids takes place by hole hopping between local sites of lowest ionizati…  相似文献   

3.
Traditional MEMS (microelectromechanical system) design methodology is not a structured method and has become an obstacle for MEMS creative design. In this paper, a novel method of mask synthesis and verification for surface micro-machined MEMS is proposed, which is based on the geometric model of a MEMS device. The emphasis is focused on synthesizing the masks at the basis of the layer model generated from the geometric model of the MEMS device. The method is comprised of several steps: the correction of the layer model, the generation of initial masks and final masks including multi-layer etch masks, and mask simulation. Finally some test results are given.  相似文献   

4.
基于MEMS和GSM模块远程监护的实验和研究   总被引:1,自引:0,他引:1  
提出了基于MEMS和GSM短信沟通平台的检测人体跌倒、自动发送手机短信报警以及紧急呼救的智能监护系统,以实现对居家老人的远程监护和突发意外的及时警报。系统由三大模块组成,其中采集模块、通讯模块和控制模块分别为SIEMENS TC35模块和MMA7260QT加速度传感器以及低功耗单片机STC12LE5204AD,采用AT指令程序实现单片机控制GSM模块自动发送跌倒求救短信。该系统较一般检测算法不同:对人体进行动静态姿势分类,自动检测是否进入省电模式并启用随时唤醒机制;预设的紧急报警按钮使用户能够及时自主求救。实验证明,基于MEMS和GSM的老人监护系统能够及时有效地对居家老人进行可靠监护,对保障老人生命安全具有重要应用意义。  相似文献   

5.
Depth maps are used for synthesis virtual view in free-viewpoint television (FTV) systems.When depth maps are derived using existing depth estimation methods,the depth distortions will cause undesirable artifacts in the synthesized views.To solve this problem,a 3D video quality model base depth maps (D-3DV) for virtual view synthesis and depth map coding in the FTV applications is proposed.First,the relationships between distortions in coded depth map and rendered view are derived.Then,a precisely 3DV quali...  相似文献   

6.
针对模具型腔粗加工的特点,提出了二维当量载荷的概念,构建了模具型腔层切加工的切削力曲面模型,并对建立的切削力曲面模型进行进给速度优化。实验证明,该进给速度优化策略对提高模具型腔加工效率十分有效。  相似文献   

7.
为了达到减少比特数同时保持画面质量的目的,提出了一种基于最小可视失真(JND)和自回归(AR)模型的感知视频编码方法.首先,设计了基于JND的纹理分割算法,建立了空时JND模型,以MB为基本单元,通过计算其JND能量并与阈值做比较,用以分割出视频序列中的纹理区域.然后,开发了AR模型来合成纹理区,在使用最小二乘法计算出AR模型的参数后,用相邻的前后参考帧对应像素的线性插值来生成重构像素.最后,为了检验所提方法的效果,将其与H.264/AVC视频编码系统做比较,用不同的视频序列实验来验证所提方法的有效性.实验结果显示,对于具有不同纹理特点的实验序列,所提方法可以在保持感知质量的同时将比特率减少15%~58%.  相似文献   

8.
A mathematical model of symmetry based on mathematical definition   总被引:1,自引:0,他引:1  
Tolerance is imperative for seamless integration of CAD/CAM (Computer Aided Disign/Computer Aided Manufacture) which is just a text attribute and has no semantics in present CAD systems. There are many tolerance types, the relations between which are very complicated. In addition, the different principles of tolerance make study of tolerance difficult; and there may be various meanings or interpretation for the same type of tolerance because of the literal definition. In this work, latest unambiguous mathematical definition was applied to study, explain and clarfy: (1) the formation and representation of tolerance zone, and (2) the formation and representation of variational elements; after which, the mathematical models of symmetry of different tolerance principles and different interpretations were derived. An example is given to illustrate the application of these models in tolerance analysis. Project supported by the National Natural Science Foundation of China for Innovation Research Groups(No.60021201) and NSFC(Nos.59705022 & 69973045).  相似文献   

9.
以 3缩水甘油环氧丙基三甲氧基硅烷对玻璃基片表面进行硅烷化后 ,用下列 4种方法组装手臂分子 :①盐酸直接处理 ;②先用聚六乙二醇 ,然后用盐酸处理 ;③用乙二胺、戊二醛、乙醇胺和硼氢化钠分别处理 ;④用聚六乙二醇、乙二胺、戊二醛、乙醇胺和硼氢化钠分别处理 .用XPS(X-ray photoelectron spectroscopy)和测定接触角的方法对上述组装进行了表征 ,并用直接偶联荧光单体及合成 2 0mer寡核苷酸与带荧光的互补探针杂交的方法对上述手臂分子的合成效率及杂交效率进行了考察 .实验表明方法③组装的手臂分子得到的结果优于其他 3种方法 ,证明了手臂分子的空间效应、亲水性等性质对寡核苷酸合成和杂交存在影响 .  相似文献   

10.
基于Matlab的DLA模型的计算机模拟   总被引:1,自引:0,他引:1  
熊裕文 《鄂州大学学报》2006,13(6):12-13,19
该文概述了分形理论的产生和DLA有限凝聚模型,分析了DLA模型的计算机模拟方法,并对模型进行了演变讨论,同时给出了模拟效果图。  相似文献   

11.
在经济增长中制造业增长是重要组成部分,影响制造业经济增长的因素很多,在分析时常用多元回归分析方法,但有时建立的回归模型拟合效果不好或不合理。为此文中利用多元统计分析方法中的主坐标分析方法,给出无多重共线性的一组互不相关的主坐标,然后建立趋势面回归预测模型。文中建立了苏州制造业经济增长预测模型,实例表明效果很好。  相似文献   

12.
针对被跟踪头部目标特征状态随时间变化而与参考模板不匹配的问题,提出一种基于融合参考模板的均值移动算法,即将被跟踪目标在不同状态下所呈现出的不同特征使用采样的方法进行融合,如将头部跟踪过程中正面的肤色信息和后面的发色信息进行融合,从而形成一个包含不同特征的参考模板.在跟踪过程中,使用该融合模板可以有效地克服由被跟踪目标特征变化导致跟踪失败而不能实现头部连续跟踪的问题.通过头部跟踪实验可以看出,该算法实现了复杂环境下的具有360°旋转的头部跟踪,并且在一定程度上提高了跟踪精度.  相似文献   

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