共查询到19条相似文献,搜索用时 203 毫秒
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混沌理论是非线性科学的重要分支,具有丰富的内涵和广博的外延空间,在很多领域都得到广泛的应用。总结混沌的重要本质特性,即非线性和内随机性、敏感性、遍历性、分维性和广谱等,分类讨论利用这些混沌特性解决有关工程实际问题的应用情况;并以电力系统这一典型的大规非线性系统为背景,分析混沌理论在电力系统稳定分析及其控制、电力系统经济调度与优化、电力统短期负荷预测以及电气设备状态监测等方面的应用研究进展。 相似文献
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非线性振动 分叉和混沌理论及其应用 总被引:12,自引:1,他引:11
本文主要是从非线性振动的角度出发综述了近年来国内外在非线性振动、分叉和混沌理论及其应用方面的主要成果和发展前景。首先,本文回顾了非线性振动理论的历史,阐述了应用分叉和混沌理论研究非线性振动系统的必要性,进而给出了近期非线性振动八个重点方面的研究方向。其次,我们详细地综述了非线性振动系统的解析方法、非线性振动系统的局部分叉理论及分析方法、非线性振动系统的全局分叉及混沌、非线性随机系统的振动与分叉理论四个方面近期国内外研究工作的主要成果和进展。最后,本文说明了今后分叉和混沌及其应用于非线性振动的主要研究内容。 相似文献
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线谱混沌化是提高潜艇声隐身性能的主要手段,但难以实现小振幅下的持续混沌化;同时,非线性隔振系统由于多个吸引子共存,混沌化品质依赖于初始条件和系统参数。为此,利用开环加非线性闭环方法研究两自由度非线性隔振系统的吸引子迁移和线谱混沌化。建立两自由度非线性隔振系统的动力学方程并分析其全局性态,得到系统的全局分岔特性及吸引子共存规律;通过开环加非线性闭环方法实现不同吸引子之间的迁移控制,使系统在不同初始条件下始终运行于基础振动最小的混沌吸引子上;利用开环加非线性闭环耦合方法实现驱动系统和响应系统之间的广义混沌同步,使系统在不同参数下始终处于小振幅持续混沌运动。仿真结果表明该方法具有可行性和稳定性,能实现隐匿线谱信息和保持隔振性能的双重功能。 相似文献
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水下辐射噪声中的低频线谱是影响潜艇声隐身性能的主要因素,线谱混沌化控制技术通过处于混沌状态的非线性隔振系统将低频线谱转换为宽频混沌谱,可以实现频谱重构并降低线谱强度。前期研究表明,利用广义混沌同步方法可以实现变工况下隔振系统的持续混沌化,在某些情况下还能显著减小振幅,为线谱混沌化控制理论提供了新思路。然而,目前要利用广义混沌同步产生小振幅的持续混沌运动,只能通过"试错"来选择合适的混沌同步控制策略,还没有形成系统的方法。为此,提出了一种混沌同步控制策略构造方法。结合耦合Duffing隔振系统对该构造方法进行验证和说明,并将该方法应用于两自由度非线性隔振系统。 相似文献
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M. Mahendran 《工程教育杂志》1995,84(1):75-79
Problem solving is an essential element of civil engineering education. It has been observed that students are best able to understand civil engineering theory when there is a practical application of it. Teaching theory alone has led to lower levels of comprehension and motivation and a correspondingly higher rate of failure and “drop-out”. This paper analyses the effectiveness of introducing practical design projects at an early stage within a civil engineering undergraduate program at Queensland University of Technology. In two of the essential basic subjects, Engineering Mechanics and Steel Structures, model projects which simulate realistic engineering exercises were introduced. Students were required to work in small groups to analyse, design and build the lightest / most efficient model bridges made of specific materials such as spaghetti, drinking straw, paddle pop sticks and balsa wood and steel columns for a given design loading/target capacity. The paper traces the success of the teaching strategy at each stage from its introduction through to the final student and staff evaluation. 相似文献
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In this paper, we have discussed the application of new nonlinear recursive controllers on Josephson junction (JJ) chaotic systems. Controlling bifurcation as well as chaos has been rapidly advancing in the last decade. Thus, emphasis has been placed on control design techniques which result in prescribed nonlinear performance dynamics for practical controlled processes. This study has shown that a nonlinear recursive controller is effective in controlling an undesirable JJ chaotic behavior. In addition to that, the synchronization of two JJ chaotic nonlinear dynamical systems can be used to advantage in communication systems. In fact, communication security is promising through chaos. Using nonlinear control method, we have demonstrated that it is possible to achieve synchronization in electronic circuits such as JJ. The study showed the effectiveness of the designed controller in communication signal synchronization. For the purpose of verification and comparison, we designed a control signal based on master and slave concept. 相似文献
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Engineering Design in Industry: Teaching Students and Faculty to Apply Engineering Science in Design
In a typical engineering curriculum students and faculty rarely have the opportunity to take a real problem, extract its essence, apply an analysis, and then make design decisions based on this analysis. This extractive link between fundamentals and design is particularly critical to a smooth transition from engineering study at the university to engineering practice in industry. Historically, universities have taken the responsibility for rigorous theoretical and technical training in subjects that include the basic sciences and fundamentals of engineering, while industry has been responsible for making engineering graduates contributors to specific tasks important to the company and its core competency. In this division of training, however, no one teaches students how to apply fundamental engineering principles to practical problems. To make matters worse, faculty often ignore engineering relevance of basic theory and the students then reject these fundamentals; in both cases engineering performance suffers. One solution to this missing bridge is being developed in the Mechanical and Aerospace Engineering Department at the University of California, Irvine (UCI) in the form of the “Engineering Design in Industry” program. 相似文献
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混沌及高聚物的混沌运动 总被引:4,自引:0,他引:4
戈明亮 《高分子材料科学与工程》2004,20(3):17-20,24
本文首先介绍了混沌理论的发展及混沌运动的特征,随后在此基础上研究了高聚物分子链结构、构象、结晶过程及粘流行为的混沌性质,并列举出混沌理论在高分子领域的应用。 相似文献
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将混沌理论应用于弱信号检测,设计了一种由三维混沌和余弦函数合成的全新的混沌弱信号检测系统——SH-COS系统,并对其进行了动力学特性的理论分析,用Matlab及Muhisim进行了电路仿真分析.与目前广泛探讨的Duffing混沌弱信号检测系统以及锁相放大器的性能相比,新设计的混沌弱信号检测系统抗噪性能强、检测精度高,而且具有信号检测的广域多样性,弥补了检测系统混沌与大周期状态难以区分、大周期状态不稳定等不足.新系统输出的大周期态具有收敛性,仿真对比结果验证了设计方法的正确性,进一步改善了混沌系统的弱信号检测性能,使定量检测成为可能,因而更适合应用于实际工程领域. 相似文献
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Gajendra V. Patil M. A. Dharap R. I. K. Moorthy 《International Journal for Computational Methods in Engineering Science and Mechanics》2016,17(5-6):350-361
Engineering structures often have nonlinear characteristics. Many of these nonlinear systems could be modelled as piecewise linear. The dynamic analysis of such systems can be carried out by the direct integration of the mathematical model of the system. In this article, solution schemes are identified and qualified studying a single degree-of-freedom system and evaluated studying real-life engineering structures. As an alternative, a modified Newmark method with iteration for nonlinear forces and half-step error monitoring is presented. The modified scheme has been found to be efficient and accurate. 相似文献