共查询到19条相似文献，搜索用时 109 毫秒
1.
扰动对一维Theta-神经元网络中规则单放电行波解的影响 总被引：1，自引：1，他引：0
在一维Theta-神经元网络中规则单放电行波解存在的基础上,进一步从改变细胞之间的耦合网输入形式讨论扰动对规则单放电行波解的影响,得出当扰动系数ε〈1时,既不会使规则单放电行波变得不规则,也不会使单放电行波变为多放电行波,并通过数值模拟对理论加以验证。 相似文献
2.
在一维Theta -神经元网络中规则单放电行波解存在的基础上,通过对细胞之间耦合网输入形式加以扰动和噪音两方面进一步讨论了扰动对规则单放电行波解的影响,并通过数值模拟对理论加以验证. 相似文献
3.
通过对一维Theta-神经元网络中细胞耦合作用时间的讨论,得到较长时间的耦合作用时间会使网络中单放电行波变为多放电行波,并通过数值模拟对理论加以验证. 相似文献
4.
杨高翔 《西南大学学报(自然科学版)》2018,40(11):55-60
主要利用反应扩散方程的空间均匀的Hopf分支条件和其行波方程的分支条件,得到了该单种群模型的时空分布模式,主要包括空间均匀时间上周期振荡的分布模式和空间非均匀的周期行波模式.此外,还借助数值计算的方法,验证了所得的理论结果.数值计算结果发现该空间非均匀的行波解还受到时滞的影响,当时滞量增大时,该空间非均匀的行波解由波前解转化为带振荡尾巴的周期行波解. 相似文献
5.
本文主要讨论神经网络中的1个积分微分方程行波解的存在唯一性问题,本文采用相空间分析法给出了行波解的存在唯一性定理并予以证明. 相似文献
6.
神经元网络模型转化为自治系统,通过向量场分析了六个不动点的行波解的存在唯一性,并绘制出了六个不动点的向量场图,再利用matlab软件对六个不动点的行波解的存在唯一性进行数值模拟,两种方法相互印证存在六个不动点时,行波解不存在。 相似文献
7.
神经元网络中一类积分微分方程的自治系统与不动点 总被引：1，自引：0，他引：1
本文为了讨论神经网络中的1个积分微分方程行波解的存在唯一性问题,采用相空间分析的方法,给出了行波解的存在的各种情形及其满足的边值条件. 相似文献
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本文主要研究神经网络模型行波解的存在唯一性,运用Matlab软件对存在两个不动点的情况进行行波解与存在唯一波速的数值模拟. 相似文献
10.
利用动力系统方法研究一类耦合Klein-Gordon-Zakharov方程组的行波解,得到了其孤立波与周期波解的精确显式表达式,并且给出了上述解存在的明显参数条件。研究表明,动力系统理论是求解各类复杂非线性演化方程行波解的一个非常行之有效的方法。 相似文献
11.
Flätgen G Krischer K Pettinger B Doblhofer K Junkes H Ertl G 《Science (New York, N.Y.)》1995,269(5224):668-671
The potential dependence of resonance conditions for the excitation of surface plasmons was exploited to obtain two-dimensional images of the potential distribution of an electrode with high temporal resolution. This method allows the study of spatiotemporal patterns in electrochemical systems. Potential waves traveling across the electrode with a speed on the order of meters per second were observed in the bistable regime of an oscillatory electrochemical reaction. This velocity is close to that of excitation waves in nerve fibers and is far greater than the velocity of reaction-diffusion waves observed in other chemical systems. 相似文献
12.
We achieved automated optical control over coherent lattice responses that were both time- and position-dependent across macroscopic length scales. In our experiments, spatiotemporal femtosecond pulse shaping was used to generate excitation light fields that were directed toward distinct regions of crystalline samples, producing terahertz-frequency lattice vibrational waves that emanated outward from their multiple origins at lightlike speeds. Interferences among the waves resulted in fully specified far-field responses, including tilted, focusing, or amplified wavefronts. Generation and coherent amplification of terahertz traveling waves and terahertz phased-array generation also were demonstrated. 相似文献
13.
Hof B van Doorne CW Westerweel J Nieuwstadt FT Faisst H Eckhardt B Wedin H Kerswell RR Waleffe F 《Science (New York, N.Y.)》2004,305(5690):1594-1598
Transition to turbulence in pipe flow is one of the most fundamental and longest-standing problems in fluid dynamics. Stability theory suggests that the flow remains laminar for all flow rates, but in practice pipe flow becomes turbulent even at moderate speeds. This transition drastically affects the transport efficiency of mass, momentum, and heat. On the basis of the recent discovery of unstable traveling waves in computational studies of the Navier-Stokes equations and ideas from dynamical systems theory, a model for the transition process has been suggested. We report experimental observation of these traveling waves in pipe flow, confirming the proposed transition scenario and suggesting that the dynamics associated with these unstable states may indeed capture the nature of fluid turbulence. 相似文献
14.
VON BEKESY G 《Science (New York, N.Y.)》1956,123(3201):779-783
In summing up the current status of the hearing theories, it may be said that each of the vibration patterns of the basilar membrane postulated by the four major theories of hearing can be obtained by varying two elastic properties of the membrane-namely, the coupling between adjacent parts and the absolute value of the elasticity. If these two variables are adjusted to their numerical values in the cochlea of a living animal or a fresh preparation of the human ear, traveling waves are observed along the membrane. These traveling waves have a flat maximum that shifts its location along the membrane with a change of frequency-the place of the maximum determining the pitch. An enlarged dimensional model of the cochlea in which the nerve supply of the sensory organs on the basilar membrane was replaced by the skin of the arm indicates that the inhibitory action in the nervous system can produce quite sharp local sensations, which shift their place with changes in the frequency of the vibrations. 相似文献
15.
The collision of circular chemical waves in an excitable medium, the Belousov-Zhabotinskii reaction, leads to characteristic cusplike structures. The high curvatures of these structures are especially suitable for experimentally verifying the predicted proportionality between the velocity and the shape of traveling waves. A computerized spectrophotometric video technique with microscopic resolution was used to determine the proportionality factor (2 x 10(-5) square centimeter per second), which in this case is the diffusion coefficient of the autocatalytic species of the reaction system. A numerical calculation of the spatiotemporal evolution of the cusp structure is in good agreement with the experimental observations. 相似文献
16.
Excitable media are spatially distributed systems characterized by their ability to propagate signals undamped over long distances. Wave propagation in excitable media has been modeled extensively both by continuous partial differential equations and by discrete cellular automata. Cellular automata are desirable because of their intuitive appeal and efficient digital implementation, but until now they have not served as reliable models because they have lacked two essential properties of excitable media. First, traveling waves show dispersion, that is, the speed of wave propagation into a recovering region depends on the time elapsed since the preceding wave passed through that region. Second, wave speed depends on wave front curvature: curved waves travel with normal velocities noticeably different from the plane-wave velocity. These deficiencies of cellular automation models are remedied by revising the classical rules of the excitation and recovery processes. The revised model shows curvature and dispersion effects comparable to those of continuous models, it predicts rotating spiral wave solutions in quantitative accord with the theory of continuous excitable media, and it is parameterized so that the spatial step size of the automation can be adjusted for finer resolution of traveling waves. 相似文献
17.
The reversal and splitting of traveling concentration waves was observed in a one-dimensional Belousov-Zhabotinski reaction medium under the influence of low-intensity electric field gradients ( approximately 10 V per centimeter). The wave reversal and splitting were strongly correlated with a characteristic transformation of the shape of both the wave front and the refractory tail of a wave in the local field gradient. The secondary role of generated hydrodynamic flow on wave transformation was also investigated. 相似文献
18.
对临床健康家兔进行的心电图描记与分析的结果表明，所有导联都出现Ｐ波、ＱＲＳ综合波和Ｔ波．胸导联波形明显而有规律，测得的心电图电压比较高，因此胸导联描记的心电图更便于临床分析． 相似文献
19.
田翠华;许卫平;陈玉明 《张家口农专学报》2013,(3):19-24
在Eclipse平台下采用Java语言实现迷宫游戏的设计与开发。采用随机布点算法生成不规则迷宫地图,采用图的深度优先遍历算法随机生成规则地图。地图格的大小、不同在相同的窗口生成较低、中等、较高三种不同难度的规则或不规则地图。把走迷宫的对象设置成角色方块,使用键盘方向键控制当前移动点进行游戏。遍历规则地图的起点不同,把游戏分为简单、中等、高难3种难易程度。运用回溯法从入口一步步进行探索,最后找到迷宫出口,并在界面上显示出该路径。编写画布类函数Canvas(),实现游戏设置。游戏的成功开发表明,算法研究至关重要,应用这些算法开发游戏是有效的。 相似文献