提高基因表达式编程发现知识效率的回溯策略

传统基因表达式编程(GEP)编码简单,适应性强,但可能陷入局部最优的"早熟"陷阱.因此,作者借鉴生物界的"返祖现象",提出了基于回溯的基因表达式编程方法.主要工作包括:(1)在传统GEP算法中引入回溯机制,提出基于回溯策略的GEP算法GEPBS(GEP with Backtracking Strategy);(2)提出回溯检查点概念,设计等比递增检查点序列和加速递增检查点序列,约束回溯过程;(3)扩充基于回溯的GEP算法,设计了退化因子(RF),提出了按比例回溯策略GEPPBS(GEP with Proportional Backtracking Strategy);(4)通过两个实验验证了新算法的有效性,在相同条件下较传统算法的适应度最大提高了49.2%,成功率最高提高了4倍.     

求解复杂约束问题的基因表达式编程文法模型

基因表达式编程GEP是进化计算算法家族的新成员.GEP富有特色的个体编码能很方便地表达和解决一批NP问题. 但基本GEP难以表达和求解复杂约束. 主要工作包括:(1) 提出了GEP的上下文无关文法模型gepGram; (2) 从理论上证明了gepGram的表达能力和含单个非终结符的上下文无关文法相同; (3) 给出了gepGram文法可描述约束问题的GEP求解算法, 算法与基因长度具有线性伸缩性; (4) 实验证明了本文提出算法具有较高的效率,当基因长度为106时,解码仅需0.4 s.     

中国期刊全文数据库

传统基因表达式编程(GEP)编码简单,适应性强,但可能陷入局部最优的“早熟”陷阱.因此,作者借鉴生物界的“返祖现象”,提出了基于回溯的基因表达式编程方法.主要工作包括:(1)在传统GEP算法中引入回溯机制,提出基于回溯策略的GEP算法GEPBS(GEP withBacktracking Strategy);(2)提出回溯检查点概念,设计等比递增检查点序列和加速递增检查点序列,约束回溯过程;(3)扩充基于回溯的GEP算法,设计了退化因子(RF),提出了按比例回溯策略GEPPBS(GEP with Propo     

基因表达式编程中的精英个体产生策略

为提高基因表达式编程(GEP)算法的进化效率,提出了一种用于产生GEP初始种群的精英个体产生策略.该策略通过逐步扩大染色体到目标值的距离,采用随机方式在较短时间内产生具有较高个体适应度的染色体,从而在初始种群中快速产生精英个体,使种群可以从一个较高的基础上开始进化,缩短了GEP算法的进化距离,从而提高了种群的进化效率.实验结果表明,在GEP算法挖掘函数的过程中,采用文中提出的策略,可以使GEP算法的进化效率提高17%.     

多细胞基因表达式编程函数优化的并行算法研究

并行算法是当前研究解决算法效率问题的成熟技术之一。为提高GEP算法解决复杂函数优化问题的效率,将并行算法引入多细胞基因表达式编程函数优化问题,解决传统计算形式不能充分发挥多核处理器性能的问题。通过分析多细胞基因表达式编程并行算法的机理和MPI和Open MP混合并行模型,设计与实现多细胞基因表达式编程函数优化的并行算法(Parallel Multicellular Gene Expression Programming algorithm for Function Optimization)PGMFO。实验结果表明针对复杂的函数优化问题,在不影响精度和收敛性的情况下,PGMFO算法比原有的算法效率高出10%~20%。     

基于多目标基因表达式编程的电路演化算法

为提高电路演化的效率和成功率,对电路设计中涉及的多个目标进行了定义与量化,并针对多目标优化问题,在基因表达式编程(GEP:Gene Expression Programming)的基础上,提出了基于多目标基因表达式编程的电路演化算法(MGEP:Multi-Objective Gene Expression Progra...     

基于基因表达式编程的多数据流分类并行算法

针对传统决策树分类算法在多数据流分类的正确率和处理速度存在的不足,提出了一种基于基因表达式编程(GEP)的多数据流分类并行算法,以提高多数据流分类的正确率和处理速度.根据GEP在数据分类上的优势,运用GEP原理和数据流段中分类目标相似属性合并构造多数据流分类算法,并对多数据流分类算法进行并行设计与分析,在多核PC上进行对比实验.实验结果表明:该串行与并行分类算法均优于传统算法,且在多样本上具有较好的加速比.     

自适应基因表达式程序设计研究及应用

针对基因表达式程序设计(GEP)是基于基因型和表现型的新型遗传算法,它综合了遗传算法(GA)和遗传程序设计(GP)的优点,但在解决具体问题时有收敛速度较慢、易陷入局部最优和拟合度不高等缺陷,提出一种自适应基因表达式程序设计算法(AGEP),它将差分突变搜索、混沌重组和变异操作、灾变算子运用于GEP中;最后将其应用于实例中,并将其所得结果与传统的基因表达式程序设计结果进行比较。研究结果表明:该算法不仅提高了算法的精度和收敛速度,而且有效地克服了不成熟收敛,理论证明该算法全局收敛;改进的基因表达式程序设计性能良好。     

采用基因表达式编程的自适应层次聚类方法

针对层次聚类算法高维度数据计算复杂度较高、抗干扰性较差、误差较大等不足,在结合基因表达式编程(GEP)非线性演化优越性能的基础上,提出一种基于GEP计算模型的层次聚类算法(GEPHCA),寻找经过基因遗传进化适应度最高的聚类中心.通过试验对比验证可知:基于基因表达式编程的自适应层次聚类方法在实际应用中是有效的,不仅能够实现自动聚类,而且和一般的聚类方法进行比较,具有自适应迭代、速度较快、稳定高效等优点.     

一种用GEP进化神经网络结构和权值的方法

提出一种用基因表达式编程(gene expression programming,GEP)自动设计神经网络结构和权值的算法.论述算法的基本思想和基本操作,针对算法的早熟现象和变异率低问题进行了相应的改进,给出这种算法的应用实例.实验结果表明,GEP可以自动设计神经网络的结构,并能给出优化的网络权值,与其他优化算法相比,收敛速度更快.     

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