共查询到20条相似文献，搜索用时 156 毫秒
1.
基于市场结构的划分研究了企业市场竞争行为,着重分析了企业定价行为、广告行为和兼并行为,指出在特定的市场结构下企业竞争行为的选择,以实现利润的最大化。 相似文献
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Jerk电路是三阶自治系统,对系统方程的变换得到三维非线性方程组转化成可控标准型,并分析了其复杂动力学特性。证明该系统含混沌吸引子以及Jerk电路自身的混沌性,同时为了消除Jerk电路的混沌现象,克服其对系统工作状况的不利影响以及反馈控制理论中永远不能精确达到目标轨道的缺点,利用滑模变结构法,将Jerk电路系统从混沌轨道控制到任意周期轨道,MATLAB模拟验证了其有效性。结果证明滑模变结构法能够使系统严格地跟踪参考轨道,实现Jerk电路混沌控制的同时也为相关电力电子系统混沌态的有效控制提供了借鉴。 相似文献
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一类参数激励非线性振子的周期分岔序列和混沌行为 总被引：1，自引：0，他引：1
用数值方法对一类参数激励的非线性DUffing-Van der Pol振子进行了研究.着重考察了系统随周期驱动力角频率ω改变的周期分岔序列及混沌行为.给出了各种振荡态和混沌态随时间的循环模式.发现在一定的ω值区间内,周期运动和混沌运动交替出现,周期运动会失稳直接进入混沌态.对通向混沌的道路问题也作了一些探讨. 相似文献
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强迫Duffing—Van der Pol振子的混沌行为 总被引：1，自引：0，他引：1
用Melnikov-Holmes方法对如下强迫Duffing-Van der Pol振子进行了分析:给出其同宿轨道的Melnikov函数及系统产生混沌的阈值.通过数值计算,运用运动轨线的直接观察,相图分析和FFT功率谱分析方法,考察系统的周期和混沌行为.并着重研究了反馈周期驱动对系统混沌行为的影响.在小参数范围内,数值结果与理论结果符合较好.本文的研究结果将为解决非线性系统的噪声干扰问题以及获得在统计分析和Monte Carlo方法中极为有用的具有给定分布的随机信号等提供途径. 相似文献
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利用脉冲非线性状态反馈控制混沌 总被引：3，自引：0，他引：3
研究了脉冲非线性反馈控制方法控制Lorenz系统的混沌问题，首先从理论上论证了控制方法的正确性．然后设计出了三种控制器并给出了控制器应满足的条件，理论分析和数值模拟结果表明混沌Lorenz系统中的不稳定不动点能被稳定控制，而且Hopf分岔也能产生，给出了相应的数值模拟结果，例如不动点、极限环(IP)轨道，采用脉冲控制方法的优点是控制代价小，工程上易于实现，最后指出，对于其他具有平衡点对称的混沌系统如蔡氏电路系统的混沌控制，此控制策略同样有效。 相似文献
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混沌是企业非线性系统的一种本质行为,对以决定论为指导的传统企业管理哲学重新思考是必要的。基于混沌理论提出了关于企业管理观的几点看法,认为企业系统演化是驱动力与耗散力互相竞争的过程,在管理中应树立非决定论系统观,以混沌的可驾驭性为基础充分发挥人的主观能动性;探讨了企业系统的非线性描述方法、企业预测决策的非决定论方法、企业管理的系统论和分形论等方法论启示。 相似文献
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产品生命周期是指一代新产品进入市场后需求变化的周期。竞争情报的类型在某种程度上取决于对产品生命周期的理解和评价。在最初的市场导入期，竞争情报的作用是识别和监控潜在的竞争者。在产品和市场的衰退期，竞争情报人员需要做出努力来延长收益并通过各种策略来尽可能抑制市场损失。总之，竞争情报人员的作用就是收集，评价和传播情报，帮助企业在产品生命周期的各个阶段保持竞争优势。 相似文献
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搜索广告已经形成了巨大的市场规模,搜索广告市场下的平台竞争是一个重要问题.建立了搜索广告市场下的平台竞争模型,将广告主划分为高质量与低质量两种类型,以排序规则集合作为平台竞争的策略空间,将竞争过程转化为两阶段博弈,给出了不同策略组合下平台收入的解析式.研究表明:当高质量广告主的比例高于临界点时,平台的竞争均衡策略是共同采用加权排序规则,当高质量广告主的比例低于临界点时,平台的竞争均衡策略是分别采用单纯排序规则和加权排序规则.研究结果为平台企业在竞争环境下的策略选择提供了决策依据. 相似文献
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创新战略的选择与市场体制、资源状况、企业组织及经济发展状况等有着密切的关系。从西部企业存在的实际状况看，模仿创新是一种比较现实的选择。因为模仿创新可以减少创新产品的生存风险，节约投资，为弱势企业建立自己的竞争优势，步入良性发展轨道，进而逐步占领市场，提供了一条可行之路。所以，它应当成为西部企业创新战略的首要选择。 相似文献
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在均匀的交流电场作用下,应用布朗动力学模拟方法,研究了两端锚定的柔性和半柔性的单链聚电解质的动力学行为。研究结果表明,链段的位置随交流电场的变化表现出类似于磁滞回线的滞后效应,随着交流电的频率减小,这种滞后效应运渐消失,成为一条单一的曲线。本项目针对两端锚定的聚电解质随交流电场变化的动力学行为的研究,文献中未见报道。 相似文献
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In this paper, we study a discrete prey-predator system with harvesting of both species and Beddington-DeAngelis functional response. By using the center manifold theorem and bifurcation theory, we establish that the system undergoes flip bifurcation and Hopf bifurcation when the harvesting effort of prey population passes some critical values. Numerical simulations exhibit period-6, 10, 12, 14, 20 orbits, cascade of period-doubling bifurcation in period-2, 4, 8, 16 orbits and chaotic sets. At the same time, the numerically computed Lyapunov exponents confirm the complex dynamical behaviors. Moreover, a state delayed feedback control method, which can be implemented only by adjusting the harvesting effort for the prey population, is proposed to drive the discrete prey-predator system to a steady state. 相似文献
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Francis W. Sears 《Journal of The Franklin Institute》1930,209(4):459-472
The Continuous Integraph has been used to trace the orbits of an electron oscillating within the filament-plate space of a three-electrode vacuum tube, such oscillations being presumably the origin of the Barkhausen-Kurz Effect. The effects of space-charge, initial velocity of emission, and amplitude of oscillations are considered. The results check and extend those of Kapzov found by other methods. 相似文献
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The radial and axial motions of electrons in the betatron are described by means of a potential function of forces. Previously reported conditions of equilibrium, stability and damping of oscillations are derived for the region of parabolic variation of the potential. Extension of the analysis to, non-parabolic regions gives an account of the injection in conventional instruments in better agreement with experiment, particularly in regard to higher voltages of injection.Space charge limitations are discussed with the help of the Laplacian of the potential of forces.By means of an additional radial electric field electrons can be introduced as in the magnetron, without any asymmetry inherent in the conventional betatron circumferential injector. The analysis of the conditions of equilibrium and stability, greatly facilitated in this case by the notion of potential, shows that no substantial improvement in space charge limitations can be expected and that the required variations between the flux linking the electron orbits and the magnetic and electric fields at the orbits are difficult to realize on account of their complexity and narrow tolerances. The X-ray output of a small experimental double yoke instrument was measured by a phototube multiplier viewing an irradiated fluorescent screen and gave evidence of multiple group electron capture. 相似文献
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安华 《科学技术与辩证法》2011,(5):103-107
通过对历史上中西技术发展进行比较,可以看出技术进步之于经济增长的关系。文章运用了技术演化的模型研究与历史实证分析,指出由于技术进步改变了生产函数和增长模式,使得中西方出现了截然不同的发展轨迹。在此基础上,文章进一步提出当代中国的技术进步对策。文章认为,依靠技术进步对策可以实现技术产业化,并最终实现集约式经济增长和转型。 相似文献
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This paper tackles in the stabilization of periodic orbits of nonlinear discrete-time dynamical systems with chaotic sets. The problem is approximated locally to the stabilization of linear time-periodic systems and the theory of modern control is applied to the Prediction-Based Control, resulting in a new control law. This control law sets all the Floquet multipliers of the stabilized orbit to zero, resulting in fast convergence of trajectories in its vicinity. Another important characteristic of the control law is that no previous knowledge about the periodic orbit is required for stabilization. Using numerical simulations, this control law was analysed and compared to an optimal Delayed Feedback Control evidencing its advantages in theoretical and practical aspects. 相似文献
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Hankins TL 《Isis; an international review devoted to the history of science and its cultural influences》2006,97(4):606-633
In 1833 John Herschel published a graphical method for determining the orbits of double stars. He argued that his method, which depended on human judgment rather than mathematical analysis, gave better results than computation, given the uncertainty in the data. Herschel found that astronomy and terrestrial physics were especially suitable for graphical treatment, and he expected that graphs would soon become important in all areas of science. He argued with William Whewell and James D. Forbes over the process of induction, over the application of probability, and over the moral content of science. Graphs entered into all these debates; but because they constituted a method, not a metaphysics, they were acceptable to most practicing scientists and became increasingly popular throughout the nineteenth century. 相似文献
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Finite-time distributed localization and multi-orbit circumnavigation with bearing-only measurements
《Journal of The Franklin Institute》2023,360(10):6712-6735
This paper investigates the localization and circumnavigation problem of a stationary target by multiple agents with multi-orbit within finite time. The agents can only obtain their own positions and the bearing information of the target. They are required to travel along their prescribed trajectories in three-dimensional (3-D) space and circumnavigate the target. First, a novel finite-time distributed positional estimator, using bearing-only measurements, is developed for agents to localize the target. Afterward, with the estimate of the target position, a distributed control law is designed to steer the agents to circumnavigate the target on different orbits with any preconcerted angular spacing distribution pattern within finite time. Simultaneously, the corresponding stability and convergence analyses are presented. Finally, simulation results are provided to demonstrate the effectiveness of the theoretical results. 相似文献
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This paper investigates the chaos control problem of a new multi-scroll chaotic system. Two nonlinear control methods are studied, namely high-order and predictive types of control. The proposed methodologies offer the possibility of stabilizing unstable periodic orbits and unstable equilibrium points from the state equations. For this purpose, we apply the high-order control method for stabilizing a desired unstable periodic orbit, while the predictive control method is applied for stabilization problem of unstable equilibrium points. In particular, these approaches are effective and easy to be implemented since we only need to apply small perturbations to the system dynamics. The multi-scroll Chen system is used as representative example to show the working principle of these methods. Numerical simulation results indicate the potential engineering applications of the proposed control methods for various multi-scroll chaos-based practical applications. 相似文献