应用粒子群序列二次规划算法的结构可靠性优化

针对粒子群算法在寻优过程中局部搜索能力较差、后期收敛慢的缺点,提出使用序列二次规划法来改进粒子群算法的局部搜索性能。该混合算法既保持了粒子群算法全局收敛的特点,又补充了序列二次规划法精确求解的能力,因此该算法可以快速获取全局最优解。应用于经典测试函数,可得到较高精度的最优解,验证了算法的有效性。对实际齿轮减速器进行结构可靠性优化设计,建立了结构可靠度约束下最小体积的优化模型,并用该混合算法方法进行优化计算,仿真计算结果表明:该方法解决结构可靠性优化问题是合理有效的。     

混合约束多峰优化问题的一个协同共轭进退粒子群算法

为解决混合（等式和不等式）约束的多峰优化问题（MOPs），本文在粒子群算法框架下提出了粒子优度比较准则和局部协同与共轭进退寻优两种迭代进化策略．优度比较准则在适应度和约束违反度的双重限制下指导粒子高效地执行进化策略，局部协同策略可使粒子能通过局部抱团收敛到多个全局最优解，而共轭进退寻优策略则提升了寻优的速度和精度．基于优度比较准则与两种进化策略的有效结合，本文设计了一个协同共轭进退粒子群（CCARPSO）算法，以充分融合粒子群算法的全局搜索能力和共轭进退法的局部快速寻优能力．数值仿真表明，该算法能有效解决复杂约束MOPs和非线性方程组的多根问题，在广义Logistic分布的参数估计中有全局优化能力和较高的计算精度．     

基于Tent映射的混沌粒子群优化算法

针对粒子群算法在迭代后期易陷入局部最优的不足,采用Tent映射所产生的混沌序列在粒子个体最优点和全局最优点附近进行混沌搜索,利用混沌搜索的全局遍历性和随机性提高了粒子群优化算法的全局搜索能力和抗早熟收敛性能。几个典型测试函数的仿真结果证明了该算法的可行性。     

共享历史最优信息搜索的粒子群算法

传统粒子群算法运行机理是通过粒子群全局最优和自身经验最优来搜索最优位置,不断迭代进化,以此趋近最优解,但该算法共享信息的局限性使其容易陷入局部最优.针对传统粒子群算法的不足,提出了共享历史最优搜索信息的粒子群算法.该粒子群体在搜索过程中,共享算法本次运行的种群个体历史最优信息、当前全局最优信息,及前几次运行过程中的种群个体历史最佳信息.通过5个经典函数的仿真实验测试,验证了该算法具有较强的全局搜索能力和收敛性.     

一种拟随机初始化模拟退火粒子群算法

针对粒子群优化算法在求解高维问题时易出现的早熟收敛、停滞现象,提出一种拟随机初始化模拟退火粒子群算法.采用Hammersley方法对算法进行初始化,可以提高算法在高维搜索空间的搜索能力,进一步将模拟退火思想引入到粒子群优化算法中,结合粒子群优化算法的快速寻优能力和模拟退火算法的概率突跳特性,使算法具有跳出局部最优从而实现全局最优的能力.分别在5个经典测试函数上测试算法的性能,仿真实验结果表明,提出的算法有效克服了传统粒子群优化算法在求解高维空间优化问题时易出现的停滞现象,在进化后期仍保持较强的搜索能力,提高了传统粒子群优化算法在高维空间的全局寻优能力.     

全局粒子群优化算法

针对粒子群优化算法在解决大维数的无约束优化问题时具有较差的收敛性和稳定性,提出了一种全局粒子群优化(GPSO)算法.GPSO算法引入了一种新的惯性权重,它被定义为一个指数型函数与一个随机数的乘积,这有利于维持算法的全局搜索和局部搜索.同时,GPSO算法对全局最优解进行了小的扰动,这可以有效地避免算法早熟.使用三种粒子群优化算法来解决6个无约束优化问题.仿真结果说明,与其他两种粒子群优化算法相比,GPSO算法具有更快的收敛速度和更强的逃离局部最优的能力.     

一种求解复杂优化问题的改进粒子群优化算法

为了提高粒子群优化算法中粒子搜索最优解的效率,该文在标准粒子群优化算法的基础上,提出一种改进的粒子群优化算法。该方法通过对粒子飞行轨迹的分析,对种群中每个粒子构建了评价粒子性能差异的等级标准,并对认识系数和社会系数设计了对应的动态变化系数模型。通过引入迁徙策略,使迁徙行为随机生成的新粒子更有可能接近全局最优解,更加有利于群体搜索跳出局部最优解和寻找全局最优解。实验结果表明,与其他比较算法相比,该文提出的改进粒子群优化算法具有寻优能力强和搜索精度高等优点,测试准测上的实验数据验证了改进算法的有效性和可行性。     

融合榜样学习和反向学习的粒子群优化算法

为了提高粒子群优化算法(Particle swarm optimization,PSO)的优化效率,降低其陷入局部最优的概率,提出了一种融合榜样学习和反向学习的PSO算法(PSO based on combing Example learning and Opposition learning,EOPSO).首先,对粒子群中的非最优粒子采用新颖的榜样学习机制更新,以便提高全局搜索能力,避免算法陷入局部最优;其次,对粒子群中最优粒子采用反向学习混合机制更新,提升该粒子的搜索能力,进一步避免算法陷入局部最优;最后,对粒子群中的最优粒子还采用了自身变异机制更新,有利于搜索前期的全局搜索和后期的快速收敛.在15个不同维度的基准函数上进行了仿真实验,实验结果表明,与最先进的PSO改进算法ELPSO、SRPSO、LFPSO、HCLPSO相比,EOPSO优化性能更好.     

基于变邻域搜索改进的冲突解脱粒子群算法

飞行冲突解脱是航空器安全运行的关键,粒子群优化(particle swarm optimization,PSO)算法和变邻域搜索(variable neighborhood search,VNS)算法都可以用于解决飞行冲突,但PSO算法接近最优解时收敛速度降低,VNS算法的全局搜索能力较差。为融合PSO算法全局搜索的快速收敛特性和VNS算法的局部搜索能力,提出了变邻域搜索改进的粒子群优化算法。仿真结果证明该算法能够快速搜索到全局最优解,继承了二者的优势,同时提高了最终解脱航迹的适应值,并减少了收敛时间。     

一种新的求解优化问题的混合粒子群算法

将粒子群优化算法与一种自适应局部搜索算法相结合,提出了一种新的混合粒子群优化算法,使粒子群算法寻优过程中的全局搜索能力和局部搜索能力良好平衡;采用了典型函数和模糊神经网络优化问题对算法性能进行测试,并与其它方法进行比较.实验结果表明,这种混合粒子群优化算法能获得质量更好的解,具有较高的收敛性,特别是在高维复杂函数优化上具有很强的竞争力,其性能大大优于单一的优化方法.     

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

正~~