改进的遗传算法及其仿真

从分析标准遗传算法存在的缺陷入手,提出了一种自适应选择交叉概率、变异概率以及交叉位置非等概率选取的改进的遗传算法并予以仿真,在仿真的基础上对标准遗传算法与改进遗传算法进行性能比较．     

基于遗传算法的ERP中生产批量问题的研究

在ERP中生产批量的主要目标是通过确定最优的生产批量，使得生产费用、调整准备费用和库存费用综合指标最小。本文改进遗传算法并用于单级单项无能力约束批量计划问题（SSULP）、单级多项目无能力约束批量计划问题（SMULP）。通过仿真揭示了SSULP、SMULP采用改进遗传算法在最优解性能方面都要优于基本遗传算法。     

一种基于改进遗传算法的文本特征选择方法

文本特征选择对提高文本分类的速度和准确率,改善网络信息过滤效果至关重要．把特征选择看作优化组合问题,提出用遗传算法进行文本特征选择．传统遗传算法适应性较差,本文对传统遗传算法交叉概率、变异概率、更新策略等重要参数和关键环节作了改进,实验验证了该算法的有效性．     

一种基于模糊规则遗传算法在车间布置中的应用

提出了一种将模糊控制规则引入遗传算法的方法．根据每一代种群中所有个体适应度值的变化，对交叉概率、变异概率和染色体交叉长度进行模糊调整，很好地抑制了遗传算法的早熟现象，提高了搜索的效率．归纳出模糊调整规则，并叙述了应用模糊规则对交叉概率、变异概率和染色体交叉长度进行调整的策略；给出了模糊控制器的设计．用该模糊遗传算法对制造系统中的车间布置问题进行了仿真．结果表明，该算法是一种效率很高的寻优方法．     

一种改进的最优保存人机交互遗传算法

提出一种改进的最优保存的遗传算法IGABP，通过对个体进行局部改进，并且通过提高交叉、变异操作生成最优解的概率．极大的改进了算法的效率．理论分析和实际应用都证明了算法的有效性．     

面向排课系统的遗传算法改进研究

为了解决实施学分制对排课所造成的困难,改进了排课系统中使用的遗传算法。基于遗传算法的原理以及在排课系统中的应用,指出了交叉和变异概率选择的盲目性,并提出了遗传算法中染色体编码设计和含动态调整参数的交叉变异概率选择的改进措施。采用仿真实验的方式验证了改进后的遗传算法,结果表明,改进算法减少了无效的染色体和交叉变异操作,提高了收敛速度和全局搜索能力,克服了遗传算法的早熟和局部收敛的问题。     

基于生物入侵思想的自适应遗传算法优化

为了改进遗传算法的性能,针对标准遗传算法存在的早收敛及稳定性差的缺点,分析这一问题的原因及应对措施。选择使用基于生物入侵思想的自适应遗传算法进行优化,根据种群的实际情况对交叉概率、变异概率及入侵概率进行动态调整,使算法具有更好的鲁棒性。通过对标准遗传算法、自适应遗传算法、改进的自适应遗传算法和基于生物入侵思想的自适应遗传算法进行仿真验证得知,优化后的算法具有更好的适应度曲线,表明其能够有效的克服不成熟收敛,具有更快的收敛速度及更好的的稳定性。     

自适应遗传算法

自适应遗传算法采用自适应的适应度函数、交叉概率及变异概率代替固定的适应度函数、交叉概率及变异概率,与基本遗传算法相比,结果证明改进的遗传算法显著提高了收敛性能,并且具有很强的自适应能力.     

基于改进遗传算法多体模型的汽车悬架参数优化

针对遗传算法普遍存在的概率参数主观选取问题、早熟问题以及汽车悬架优化模型采用集中质量模型问题,提出了改进遗传算法,采用交叉算子和变异算子分别独立作用于父代个体,使父代所有个体都进行交叉和变异来避免概率参数的选取问题;然后按父子混合杰出者选择策略产生子代个体;使用局部多次搜索算子和替换策略来加快遗传算法的收敛速度;建立遗传算法和ADAMS软件的接口,使用专业软件ADAMS来处理复杂目标函数和适应度的求解问题,实现复杂多体模型的遗传算法优化。通过对33自由度的汽车悬架多体模型进行优化分析并和传统优化方法、标准遗传算法和小生境遗传算法进行对比,结果表明该方法明显优于其它方法。     

一种改进的两代竞争遗传算法

两代竞争遗传算法改变了简单遗传算法的选择机制，提高了搜索效率．但是两代竞争遗传算法易出现早熟现象，局部寻优能力并未改善．针对这些问题作者提出了一种改进算法，通过变异概率和交叉、变异范围的自适应调整，改善两代竞争遗传算法的搜索性能．实验表明，改进算法克服早熟现象，且能提高算法的局部寻优能力．     

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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