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排序方式: 共有341条查询结果,搜索用时 15 毫秒
1.
矢量图形智能判断技术的研究与应用 总被引:1,自引:0,他引:1
研究矢量图形识别是建立工程制图自动阅卷与计算机辅助教学系统的基础。由于组成二维矢量图形图元类型的多样化及图形整体位置状态的不确定性,增加了矢量图形的识别与判断难度。结合开发的《三视图智能解答》系统,研究其智能识别与判断技术。系统中引入三视图导航技术,解决了图形整体定位与识别问题。实现了对矢量图形图元素信息的分类和提取,能够对所提取的的信息与标准答案进行智能判断与评定。该方法已在AutoCAD2000环境下使用AutoLISP语言编程实现。 相似文献
2.
建立了混合驱动五杆机构系统的机电耦合动力学模型.采用滑模变结构控制方法实现了对混合输入型五杆机构运动轨迹的精确控制,并给出了仿真结果.该控制方法具有控制算法简单、易于工程实现的优点. 相似文献
3.
《材料科学技术学报》2019,35(11):2693-2704
Three-dimensional finite element (FE) models of carbon/epoxy composite laminates with copper mesh and aluminum mesh protection were established subjected to lightning strike, in which different mesh spacing was selected. Effectiveness of numerical method was verified and impulse current waveforms with different current peaks were applied according to aircraft lightning zones. Thermal-electrical material parameters varying with temperature were added into numerical models. Element deletion method was used to deal with lightning ablation elements of composite structures. The results show that ablation area and depth of composite laminates with metal mesh protection are significantly smaller, which proves good protection effectiveness of metal meshes on anti-lightning strike. The denser the mesh spacing, the better the anti-lightning strike will be. Protection of composite laminates with copper mesh has better effects than that of aluminum mesh. Considering the effect of mesh spacing variation on composite structural weight and anti-lightning strike, the ideal mesh spacing was obtained. 相似文献
4.
采用威尔金森(Wilkinson)功分器和宽带移相器级联的馈电网络具有良好的功分移相特性,可用于多模导航天线的设计.首先对馈电网络的宽带移相器进行了理论分析,然后采用HFSS软件对其短路及开路支节的参数进行了仿真,分析了其参数变化对馈电网络功分及移相特性的影响.仿真结果表明,优化参数的尺度可使馈电网络获得更宽的功分移相特性. 相似文献
5.
The corrosion process of phenolic epoxy coated tinplate in energy drink was investigated by in-situ electrochemical impedance spectroscopy(EIS) and electrochemical noise(EN) techniques. The experimental results indicate that the degradation process of novolac epoxy coated tinplate in energy drink can be divided into three main stages: organic coating wetted by the beverage; corrosion initiation beneath the organic coating; and corrosion extension process. It was proposed that the tin coating and carbon steel were mainly corroded by organic acids in energy drink through the pores of the organic coating. After the tin coating was corroded, the carbon steel started to corrode due to its higher electrochemical activity and became to be the dominated corrosion reaction. 相似文献
6.
k-median问题的近似算法研究一直是计算机科学工作者关注的焦点。基于均衡限制条件,利用反向贪心策略,给出求解该问题的随机近似算法。证明该算法以较大的概率满足其近似性能比的期望值为(3+O(ln(ln(k)/α))。该算法的时间复杂度为O([kαln(k)]2(n+m)),其中n和m分别代表设施集合以及客户点集的大小。最后,通过计算机实验验证了k-median问题的反向贪心算法的实际计算效果。 相似文献
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介绍了以温度传感器TMP04为检测器件的风速传感器的测量方法。系统以单片机AT89C51为核心,由风速传感器采集数据,单片机接收并处理数据,LED数码管显示测量风速值。采用分段插值法进行非线性数据处理;描述了电路设计和软件实现。由于采用了数字温度传感器做检测器件,省去了放大电路和A/D转换器,测量电路与单片机接口简单,编程处理简单。 相似文献
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10.
The absolute free energy difference of binding (ΔG) between neuraminidase and its inhibitor was evaluated using fast pulling of ligand (FPL) method over steered molecular dynamics (SMD) simulations. The metric was computed through linear interaction approximation. Binding nature was described by free energy differences of electrostatic and van der Waals (vdW) interactions. The finding indicates that vdW metric is dominant over electrostatics in binding process. The computed values are in good agreement with experimental data with a correlation coefficient of R = 0.82 and error of σΔGexp = 2.2 kcal/mol. The results were observed using Amber99SB-ILDN force field in comparison with CHARMM27 and GROMOS96 43a1 force fields. Obtained results may stimulate the search for an Influenza therapy. 相似文献