着舰指挥官指令操作关联引导系统建模

为保证航母舰载机着舰过程中着舰指挥官(Landing Signal Officer,LSO)对于驾驶员操作引导的安全性,建立了一种"LSO-驾驶员-舰载机"指令操作关联引导系统,通过深入剖析LSO引导任务,明确控制难点,定义指令操作基元概念,阐述引导着舰纠偏过程中的指令操作基元的集合性,设计建立LSO指令操作关联引导模型,LSO依据舰载机实时飞行状态下达"飞行状态关联指令",驾驶员依据LSO指令执行"指令关联操作",可以实现完整的指令操作基元响应纠偏.针对不同飞行偏差状态下指令操作关联引导过程进行仿真,结果表明本文设计的引导控制模型对于着舰偏差修正准确,纠偏策略符合实际着舰情况,为舰载机着舰安全性的提高提供了帮助.     

引导混沌轨道的最优反馈控制

为改善最优引导控制的抗噪声能力,提出一种可用来引导混沌轨道的最优反馈控制模型,该模型考虑了引导控制速度、精度等综合指标.从非线性系统全局反馈控制的角度来看,这种方法提供了一种用最优控制方法来选择反馈控制有关参数的新思路.文中使用十进制编码的遗传算法进行最优控制问题的求解.大量以Hénon映射为引导对象的数值实验表明,最优反馈引导控制在抗噪声能力、问题求解难度方面都比传统开环模型具有更好的性能     

基于实际行为策略的飞行员着舰模型

从飞行员人工下滑进场着舰过程中操纵舰载机的行为机理出发,建立了基于实际行为策略的飞行员着舰模型.最终动作采用离散动作序列的方式,基于一系列可分割的动作集合对飞行员操纵过程进行描述.在不同着舰环境下,飞行员模型在纵向、横向和油门操纵回路上动态切换操作策略和注意力.采用变分辨率离散化、专注模式协调策略以及误差叠加模型等方法对相应子模块进行建模.此外,模型含有设置不同能力指标和着舰指挥官的接口,用于模拟不同飞行员的行为动作.通过仿真平台对不同等级的飞行员模拟可知,建立的飞行员模型符合实际飞行员的动作机理和特性,能区别不同飞行员在表现水平上的综合差异.     

具有未知阶数和系数的线性随机系统的自适应控制

该文考虑具有未知阶数和系数的离散时间线性随机控制系统(ARMAX模型),提出一种便于在线实施的自适应控制新算法。在一定的条件下,该算法能保证所建立的闭环系统全局稳定和输出跟踪渐进最优,而且阶数和系数的估计都具有强一致性,同时还给出系数估计的收敛速度。仿真结果表明所提出的自适应控制的新算法是有效的和可行的,且控制量在容许控制的范围之内。     

汽车自动巡航系统智能控制策略

为了在汽车巡航控制中实现车距控制,在汽车模型及其工作原理的基础上,建立了基于模糊控制理论的基本控制策略和利用神经元修正的车距智能控制的方案,并设计了模糊控制和单神经元的控制策略,以基本的模糊控制和神经元修正模块组成车距控制控制器,根据汽车行驶的目标距离和实际距离之间的偏差和速度大小来调接控制参数,采用神经元控制对模糊决策得出的输出控制量进行加权修正。仿真结果表明了所设计的智能控制策略的可行性和有效性。     

基于神经网络逆模型的污水pH值内模控制策略

针对污水处理中和反应过程pH值控制具有强干扰和模型参数易变等特点，利用内模控制方法的设定值响应和干扰响应之间相互独立的优点，提出一种基于内模控制和神经网络逆模型相结合的pH值优化控制策略。通过在系统中插入低通滤波器，并采用RBF神经网络在线辨识被控对象的逆模型，提高污水处理pH值控制的鲁棒性和抗干扰能力，有效解决中和反应pH值控制过程中模型参数易变的问题。MATLAB仿真结果表明：与常规PID控制和不带滤波器的神经内模控制策略相比，提出的优化控制策略超调量最多降低17.4%，调节时间最多减少113.6 s，有效提高了系统鲁棒性和抗干扰能力。工程应用表明：使用所提策略后，pH值控制偏差在±0.2以内，系统的控制精度和稳定性显著提高。     

基于Hammerstein模型和GA的非线性广义预测控制

针对Hammerstein型的非线性系统,给出了一种基于GPC的预测控制方法.分析了使用近似法求解控制量的缺点,据此提出了基于遗传算法的控制量优化求解策略.以一个热交换器作为仿真实例,分别使用遗传算法和两种近似法求取控制量,并比较了3种情况下的控制效果.仿真结果表明基于遗传算法的预测控制器具有良好的性能.     

非线性模型的线性近似条件研究

测量数据处理中不同的非线性模型具有不同的非线性强度,从而使得一些非线性模型可以线性近似,而另一些选择适当的参数变换后可以线性近似,还有少数不能线性近似．介绍了度量非线性模型和附加限制条件的非线性模型的非线性强度的方法,提出了判断非线性模型和附加限制条件的非线性模型线性近似的数值标准———容许曲率和容许偏差．此外,还给出了实例,说明以上方法的可行性     

一类带停时的奇异型随机控制模型的推广

以随机分析的知识和最优控制理论为基础,讨论了一类带停时的奇异型随机控制的折扣费用模型.在原模型状态过程的基础上添加了漂移因子,并将扩散因子由1推广为一个正常数σ,分退化和非退化两种情况讨论了该问题相应的变分方程的解.给出了此随机控制问题的最优策略,即最优控制和最优停时.通过算例,验证了变分方程的解即为最优费用函数.     

基于顾客选择行为的存量控制稳健模型

针对销售系统不能完全记录顾客到达情况,难以准确收集和分析顾客选择偏好,存在较大需求预测误差,使得基于选择行为的存量控制模型在应用中往往达不到理论预期效果的问题,为了系统地减少最优控制策略对需求预测误差的敏感性,应用马尔可夫决策过程理论和稳健最优化方法建立存量控制的稳健模型,并同时考虑超订问题;在证明最优值函数单调的基础上,构建了一种稳健竞标价格策略.数值模拟算例表明,在需求预测误差较大情况下,最优稳健策略比一般最优策略更能够提高总收益.     

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.     

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     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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