基于多目标协同优化算法的卫星结构优化设计

针对卫星系统中多目标、多约束、耗时的结构优化问题,建立了卫星结构的多目标协同优化模型.将协同优化方法与全局多目标优化算法相结合,并针对协同优化方法的缺陷采取一些改进措施,提出了协同优化方法与全局多目标优化算法(CO-PE)组合优化方法.以某卫星结构多目标优化问题为例,在iSIGHT优化软件中对卫星结构进行多目标协同优化设计,通过CO-PE组合优化方法获取Pareto最优解集.优化结果表明,多目标协同优化模型能够简化优化问题的复杂度,基于近似模型的CO-PE组合优化方法具有较好的准确性和高效性,对实际工程中类似的复杂结构优化问题具有一定的参考价值.     

带宽优化的进化算法

介绍了实值优化问题的进化算法，自然进化是基于群体的优化过程，在计算机上模拟自然进化过程形成统计优化技术．同传统优化方法相比，进化算法具有全局优化的优点，而且适合复杂的实际问题．带宽优化是寻找结点编号的最佳排列，使得刚度矩阵的带宽最小．传统方法一般求得带宽的局部极小值，而带宽优化进化算法可求得带宽的全局最优解     

平面绞链四杆机构的改进微粒群算法优化设计

文章介绍了微粒群优化算法的原理，提出了增加种群多样性和算法随机性的改进微粒群算法及实现过程，并把该算法应用于复杂机械优化问题。实例表明，该方法全局收敛性好，是解决工程设计中复杂线性优化问题的可行方法。     

基于免疫进化的蚁群算法在梯级水库优化调度中的应用研究

针对蚁群算法在求解过程中出现初期信息素匮乏、易陷入局部最优解的问题,结合梯级水库优化调度的特点,提出了基于免疫进化的蚁群算法。该混合算法充分利用了免疫进化算法的全局快速收敛性和蚁群算法的正反馈性,提高了求解效率。实例计算表明该混合算法在求解梯级水库优化调度问题时,与逐次逼近动态规划相比较,结果合理、可靠,计算效率较高,从而为求解高维、复杂的梯级水库优化调度提供了一条新的求解思路。     

粒子群优化算法在机械优化设计教学中的应用

机械优化设计是机械类专业的一门重要的专业课,目前在机械优化教学中介绍的是传统的优化算法,这些方法对于局部极值及目标函数的可微性有严格要求,不能解决高维、多目标及优化设计问题的要求。粒子群优化算法是近几年发展起来的一种基于群体智能的进化计算技术,对优化问题无可微性和连续性要求,具有全局收敛性,本文在机械优化设计教学中引入了粒子群优化算法,为学生解决复杂工程优化设计问题打下基础。     

面向多模函数优化的改进网格优化算法

利用网格优化算法（COA）编码简单、收敛速度快、不宜陷入局部最优等特点,针对多模态函数优化问题,对GOA算法进行了改进,扩大了优化搜索范围,保持了父本种群的多样性,增强了全局搜索能力。对典型多模态函数问题的测试结果表明,改进的网格优化算法在解决多模态函数优化问题方面具有很强的全局搜索能力和很高的搜索效率。     

基于仿射算法的确定性全局优化算法

针对传统区间算法求解全局优化问题耗时长、空间复杂度较高及收敛速度较慢的缺点,引入仿射算法及局部优化算法,给出了一种全局优化求解的仿射算法.由局部优化算法和各求解区间上待优化函数的仿射运算得到全局最优解的一个上界,再依据对各区间仿射运算的下界与全局最优解上界的比较来确定相应区间的去留,通过对不含全局最优解的子区间的删除来确定最优解所在的子区间,并最终找到全局最优解.数值实验表明,该算法相对于传统的区间优化算法有较高的收敛速度,且占用的系统资源较少.     

基于遗传算法和BP算法的混合算法

结合神经网络的优化问题,提出一种新的混合算法.该算法是在遗传操作中嵌入BP算子,有效地结合了遗传算法全局寻优与BP算法快速收敛的特点,同时采用二进制编码和实数编码将神经网络的结构与权值混合编码到串中,实现了结构与权值的同步优化.仿真结果表明,新算法既能够快速地收敛到全局最优解,又能够在简化网络结构复杂度的同时得到网络权值的最佳逼近.     

一种约束工程设计问题的入侵性杂草优化算法

提出了一种新颖的求解约束问题的群智能优化算法.该算法模拟杂草克隆、占地生长与繁殖的自然行为,具有入侵性杂草的鲁棒性、适应性和随机性等特点,算法简单而有效,具有准确的全局搜索能力.结合罚函数方法将提出的算法应用于求解工程设计优化问题,实验结果及比较表明提出的算法获得了更优的结果,同时也显示了它在求解复杂工程设计优化问题时的全局寻优能力.进一步实验与统计分析了关于参数选择对算法性能的影响,得到了有利参数选择的结论.     

一个与信籁域搜索技术相结合的微粒群算法

微粒群优化算法(PSO)是一种有效的随机全局优化技术.文章针对利用微粒群优化算法进行多极值点的函数优化时,存在陷入局部极小点和搜索效率低的问题,把信籁域搜索技术引入到PSO算法中,提出了基于信籁域搜索的微粒群优化算法(TRPSO).该算法保持了PSO算法结构简单的特点,改善了PSO算法的全局寻优能力,提高了算法的收敛速度和计算精度.仿真计算结果表明,该算法的性能优于混沌微粒群优化算法(CPSO)和基本微粒群优化算法(PSO).     

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.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

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