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基于GIS的水利水电工程三维可视化图形仿真方法与应用 总被引:10,自引:2,他引:10
针对当前基于GIS的工程图形仿真技术的发展及其在水电工程领域应用的特点,研究了基于GIS的水利水电工程三维可视化图形仿真方法与应用。通过对水电工程三维可视化图形仿真系统进行系统分析、数据采集、仿真计算等工作,将所得数据进行加工处理并存于GIS内建的数据库中。在此基础上建立水电工程的三维可视化图形仿真模型。以某工程为研究对象开发了一个能直观表现水利水电工程施工总布置三维可视化图形仿真系统。 相似文献
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本文介绍了一个小型三维造型系统,着重叙述了作者独立完成的物体拼合以及显示输出子模块中的三维线框模型输出,同时介绍了该软件在制图课教学中的应用。 相似文献
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ActiveX控件技术在PDM系统三维图档管理中的应用 总被引:1,自引:0,他引:1
研究了ActiveX控件技术在图档浏览中的应用,在PDM系统中利用三维模型浏览控件SEPartX和二维工程图浏览控件SEDraftX,来实现对三维模型和其相应二维工程图的动态交互式浏览,该技术避免了图档的数据转换,为开发三维PDM系统图档管理模块提供了一种非常实用的方法. 相似文献
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VC&OpenGL技术在三维场测试和虚拟仪器中的应用 总被引:1,自引:0,他引:1
通过VC&OpenGL的编程完成了一个三维系统平台,平台能够快速构建三维场景,用颜色维表示场强,并能够对三维场分布进行点、网格、面、切片等多种形态的良好展示;系统与仪器的接口通过串口进行;同时,系统通过3DS文件导入,解决了虚拟仪器的构建和展示问题,且仪器各部分能够按要求分别进行状态改变和操作。实例展示说明了系统应用的性能。 相似文献
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本文主要研究一类具有非单调生长率的捕食食饵模型的平衡态正解问题.首先通过计算锥上紧算子的不动点指标,得到了正解存在的充分条件;其次,运用线性算子扰动理论以及拓扑度理论,讨论了参数对于正解唯一性与线性稳定性的影响;最后,通过数值模拟分别验证了在一维空间和二维空间下正解的存在性结论,也就是捕食者和食饵在一定条件下可以共存. 相似文献
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研究了一类具有线性不可控模态的非线性系统平稳分岐解的镇定问题.假定系统参数不可测量.基于不变流形理论,从原非线性系统导出了一个一维的简化方程.从简化方程的性质导出了原系统能分岐镇定的一些充分和必要条件.并举例说明了此方法的有效性. 相似文献
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本文主要研究L2(Rd)上的Gabor系成为框架或框架序列的特征。首先在时域上给出了Gabor系成为L2(Rd)上框架或框架序列的两个充分条件,并得到在特殊情形下Gabor系成为框架序列的充要条件。最后在频域上也给出了相应的结果。 相似文献
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超空泡航行体在高速航行过程中大部分表面被空泡包裹,航行体尾部与空泡间相互作用产生剧烈变化的滑行力,该滑行力是导致航行体失稳的主要因素。由于航行体与空泡相互作用机理的复杂性,使得滑行力表达式存在很大的建模差异和参数不确定性,针对这一问题,该文首先通过一系列变换将系统模型表示为线性环节和非线性环节反馈连接的形式,然后基于圆判据定理给出了航行体绝对稳定的充分条件,并依据该条件采用状态反馈极点配置方法设计控制器。仿真结果表明,该控制器针对滑行力建模不确定性和参数不确定性的情况,可以通过合理配置闭环极点实现系统对不同非线性条件的绝对稳定。 相似文献
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In many industries, production capacity diminishes as machine conditions deteriorate. Maintenance operations improve machine conditions, but also occupy potential production time, possibly delaying the customer orders. Therefore, one challenge is to determine the joint maintenance and production schedule to minimize the combined costs of maintenance and lost production over the long term. In this paper, we address the problem of integrated maintenance and production scheduling in a deteriorating multi-machine production system over multiple periods. Assuming that at the beginning of each period the demand becomes known and machine conditions are observable, we formulate a Markov decision process model to determine the maintenance plan and develop sufficient conditions guaranteeing its monotonicity in both machine condition and demand. We then formulate an integer programming model to find the maintenance and the production schedule in each period. Our computational results show that exploiting online condition monitoring information in maintenance and production decisions leads to 21% cost savings on average compared to a greedy heuristic and that the benefit of incorporating long-term information in making short-term decisions is highest in industries with medium failure rates. 相似文献
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ABSTRACTTo improve the efficiency of wafer fabrication, this work addresses the scheduling and control problems of mixed-processing with multiple wafer types in cluster tools. Then, based on a developed Petri net (PN) model, it presents a general model for cluster tools with multiple wafer types and the conventional swap strategy. By analyzing the coordination mechanism between wafers processing and robot tasks, necessary and sufficient conditions are established to check the schedulability of the system that is operated by using the conventional swap strategy. If the system is not schedulable checked by such schedulability conditions, a constraint-guided heuristic algorithm and a conflicts-avoiding algorithm are developed to obtain a reasonable schedule. Finally, illustrative examples are presented to show the applications of the proposed method. 相似文献
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C. A. Holmes 《Dynamical Systems: An International Journal》1992,7(3):163-171
Periodic orbits are sought in a mathematical model of a simple prototype chemical reaction involving essentially only two reacting species. Physically, these periodic orbits correspond to time-periodic oscillations in the concentrations of the two chemicals. Using the results for the existence and uniqueness of periodic orbits for Lienard systems, necessary and sufficient conditions are obtained for the existence of exactly one periodic orbit and of no periodic orbits. The results apply to a closed system where the quadratic autocatalytic reaction and decay step are present but the uncatalysed reaction is not and where there is only one physically relevant equilibrium solution 相似文献
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Abstract In this paper we will give some sufficient conditions that make continuous‐time bilinear systems with control delay and/or uncertainties asymptotically stable. These sufficient conditions depend strongly on the coefficient matrix measure, and on the bounds of coefficient matrices, uncertainties matrices, feedback gain matrices, and the initial state. Therefore, when a controller is designed for a bilinear system these sufficient conditions can be applied as a convenient check on the stability of closed‐loop system. 相似文献