时滞混沌神经网络的指数同步

本文研究了带有时滞混沌神经网络的指数同步问题,通过利用非线性回归控制和有效地控制定律,根据所给定的条件构造相应的线性矩阵不等式,得到了时滞神经网络的指数同步。这个方法比之前的线性控制方法更有效,数值结果进一步证明了该方法的有效性。     

基于采样控制的时滞神经网络的指数同步

基于采样控制研究了时滞神经网络的指数同步问题。首先,建立了驱动-响应时滞神经网络的数学模型并设计了采样控制器。其次,在输入延迟法的框架下,通过构造时间依赖的李雅普诺夫泛函,并结合自由权矩阵方法,建立了保证驱动-响应系统取得指数同步的线性矩阵不等式形式(LMIs)的判据。最后,通过两个数值仿真算例验证了结果的可行性。     

具时滞离散型神经网络指数同步问题

给出了具有时变时滞的离散型神经网络全局指数同步的定义,并对一类具有时变时滞的离散型时滞神经网络的全局指数同步问题作了详细的研究,得出了一类离散型神经网络全局指数同步的充分性判据,可通过LMI工具箱检验判据有效性。     

时滞细胞神经网络全局同步的滑模控制方法

利用改进的滑模控制方法,研究了具有多时滞和分布时滞细胞神经网络的全局同步问题.基于Lyapunov稳定性原理,运用线性矩阵不等式方法,设计滑模面,考虑了时滞独立和时滞相关两种情况.设计了合适的滑模控制器,以使得误差系统的轨迹能全局达到滑模面.得到了相对充分的条件,来确保时滞独立与时滞相关两种情况下误差系统的全局稳定性,从而实现时滞细胞神经网络的全局同步.结果表明所设计的滑模控制器由误差反馈控制输出来获得高增益补偿的准则,可用以处理神经网络的全局同步问题,并且此方法可应用于其他复杂神经网络.     

具有脉冲效应和Leakage项时滞的随机扰动模糊细胞神经网络的指数同步

研究了具有脉冲效应和Leakage项时滞的随机扰动模糊细胞神经网络的指数同步,通过李雅普诺夫稳定性理论、随机微分方程理论、随机分析法、It?'s公式及一些不等式方法,基于p-范数下得到了新的指数同步的充分条件.在本文中所考虑的脉冲效应是一般函数,而不是线性函数;还发现随机扰动和Leakage项时滞对系统同步有抑制作用.     

分布时滞区间神经网络的脉冲同步控制

利用脉冲控制方法研究了具有分布时滞的区间神经网络的全局指数同步问题,充分考虑了分布时滞和不确定的区间参数对系统的影响.设计了一个新的脉冲控制器来保证区间神经网络的全局指数同步,整个系统的同步在很大程度上依赖于本文所设计的脉冲控制器.通过构造Lyapunov函数,利用脉冲微分不等式技术及其它数学方法,给出了驱动系统和响应...     

一类离散神经网络的全局指数同步探析

定义了离散型神经网络全局指数同步的概念,研究了一类离散型时滞神经网络的全局指数同步问题,给出了这类神经网络全局指数同步的充分性判据,判据的有效性可通过LMI工具箱得到检验.     

一类随机离散神经网络全局渐近同步

研究离散型时滞随机神经网络的同步问题,考虑了参数不确定性,解决离散型分布时滞对神经网络同步问题的影响.基于主从同步的概念,设计一个有更广泛应用的控制器,应用Lyapunov稳定性理论和线性矩阵不等式工具箱,得到这类神经网络同步的充分性判据.最后给出实际例子,检验了判据的有效性.     

基于反馈控制的分数阶时滞神经网络的同步

研究了分数阶时滞神经网络的同步问题,通过使用Mittag-Leffler函数和线性反馈控制,给出了同步控制器解析式,得到了关于Caputo导数的时滞神经网络同步的充分条件;系统同步的条件容易证明和实现且仅依赖于系统的结构;最后通过数值模拟验证了理论的有效性.     

时标上具有离散时滞的Wilson-Cowan网络同步

在时标上微积分理论的基础上研究了具有离散时滞的Wilson-Cowan网络的全局指数型同步。通过构造Lyapunov函数,运用线性矩阵不等式和Kronecker积运算等方法,得到了时标上具有离散时滞的Wilson-Cowan网络全局指数型同步的充分条件,即当系统满足定理1中的线性矩阵不等式时可达到全局指数型同步。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the