共查询到20条相似文献，搜索用时 578 毫秒
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基本遗传算法适应度及遗传算子设计简单,求解复杂优化问题易于早熟,收敛速度慢等缺点.基于遗传算法基本框架,设计新的适应度函数,减少遗传算法中的交叉算子,改进其变异方式,提出一种改进的遗传进化算法. 相似文献
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遗传算法作为一种基于生物进化机制的自适应算法,适用于各类复杂系统的优化计算。然而标准遗传算法所具有的易早熟、易陷入局部最优等问题,在一定程度上限制了遗传算法的推广和使用。在对遗传算子做出改进的基础上,提出了一种基于小种群策略的并行遗传算法,从而有效地提高了遗传算法的执行效率和性能。 相似文献
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针对遗传算法在求解复杂优化问题时收敛速度慢,易陷入局部最优的不足,对标准遗传算法进行改进,将交叉概率和变异概率进行自适应调节,再结合移民策略,提出可自适应调节参数的改进遗传算法,应用该算法对装箱问题进行相应研究。 相似文献
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针对遗传算法在求解复杂优化问题时收敛速度慢，易陷入局部最优的不足，对标准遗传算法进行改进，将交叉概率和变异概率进行自适应调节，再结合移民策略，提出可自适应调节参数的改进遗传算法，应用该算法对装箱问题进行相应研究。 相似文献
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张清富 《广东广播电视大学学报》2009,18(5):101-105
为克服经典遗传算法求解智能组卷时存在的盲目搜索、收敛速度慢和个体易“早熟“等缺点,文章提出了基于动态自适应技术遗传算法。利用求解问题的特征改进经典遗传算法的多个关键部分,采用动态自适应技术,提高算法的寻优速度。实验结果表明,采用改进式的自适应遗传算法实现的组卷策略具有收敛速度快、搜索精度高、鲁棒性强等特点,具有很好的性能与实用性。 相似文献
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由于BP网络存在学习效率低、收敛速度慢、易陷入局部极小状态、适应能力较差等缺点,而粒子群优化（PSO）算法的收敛速度快（尤其是在进化初始阶段）,运算简单、易于实现,又没有遗传算法的编解码和杂交、变异等复杂运算,因此是一种很好的优化算法。但是,PSO算法也存在不足,该算法进化后期存在速度变慢以及早熟的现象。提出一种改进的粒子群BP神经网络对高炉炉温进行预测。通过调整粒子群算法中学习因子的自适应能力,提高算法的收敛速度和搜索全局最优的能力。通过仿真结果说明改进的粒子群算法要优于BP算法和标准的粒子群算法。 相似文献
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基于对数据挖掘,特别是关联规则挖掘的研究,提出了一种改进型遗传算法的关联规则提取算法,并从编码方法、适应度函数的构造和遗传算子的设计方面进行讨论分析。通过对早熟问题的分析并改进自适应算子,提高了算法的效率,使算法在相对稳定的动态种群规模中寻找优质解。 相似文献
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一种基于实数编码的自适应遗传算法 总被引：1，自引：0，他引：1
分析了进化遗传算法的弊端。提出了一种基于实数编码和自适应变异率的改进遗传算法,将变异率定义为自上次进化以来未进化次数的函数,同时采取最优保存策略,有效地避免了采用二进制编码时计算精度与计算量之间的矛盾,克服了基本遗传算法因变异率选择不当引起的“早熟”现象及后期收敛速度慢的问题。计算结果表明,新方法成功地解决了进化遗传算法存在的问题,且计算效率较高。 相似文献
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为解决传统遗传算法在一维多峰函数优化中容易陷入局部极值、收敛概率低、稳定性不理想等问题,提出了一种新型的自适应遗传算法。结合自适应差分进化算法流程,提出了一种基于种群适应度变化程度而变化的非线性交叉算子和变异算子,使算法跳出局部极值,寻找到全局最优解,提升最优值迭代效率。函数测试实验表明,在一维多峰函数优化中,该算法在函数收敛概率、最优值迭代效率以及稳定性上比已有算法均有提高。 相似文献
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邱崇丙 《唐山师范学院学报》2014,(1):21-23
汉字的六书,《说文》对“转注”一类,语焉不详。后世学者提及转注,也仅限于许慎所举出的例字。《汉字例说》一文,作者从转注的角度综合考虑,对部分现代常用字作了分析,跟传统的解释有所不同。希望能抛砖引玉,互相切磋,以推进学术研究。 相似文献
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Rachel Zupek 《海外英语》2007,(11):40-41
我们绝大部分人都同意一件事情——我们喜欢金钱。但是你对金钱的喜欢之情足够到让你创立一份事业么?.财富通常被人忽视,主要在于人们不能真正了 相似文献
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《海外英语》2007,(4):36
There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love. 相似文献
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YANGShiguo 《重庆大学学报(英文版)》2004,3(1):86-88
The problem on the geometrc inequalities involving an n-dimensional simplex and its inscribed simplex is studied. Aninequality is established, which reveals that the difference between the squared circumradius of the n-dimensional simplex andthe squared distance between its circumcenter and barycenter times the squared circumradius of its inscribed simplex is not lessthan the 2(n-1)th power of n times its squared inradius, and is equal to when the simplex is regular and its inscribed siplex is atangent point one. Deduction from this inequality reaches a generalization of n-dimensional Euler inequality indicating that thecircumradius of the simplex is not less than the n-fold inradius. Another inequality is derived to present the relationship betweenthe circumradius of the n-dimensional simplex and the circumradius and inradius of its pedal simplex. 相似文献
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Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject. 相似文献
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GUO Bao-feng Xiao Da-wei 《重庆大学学报(英文版)》2005,4(3):129-133
Using virtual reality for interactive design gives a designer an intuitive vision of a design and allows the designer to achieve a viable, optimal solution in a timely manner. The article discusses the process of making the Virtual Reality System of the Humble Administrator＇s Garden. Translating building data to the Virtual Reality Modeling Language （VRML） is by far unsatisfactory. This creates a challenge for computer designers to do optimization to meet requirements. Five different approaches to optimize models have been presented in this paper. The other methods are to optimize VRML and to reduce the file size. This is done by keeping polygon counts to a minimum and by applying such techniques as object culling and level-ofdetail switching. 相似文献
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The awareness of individualism can be traced back to the period of American Revolution when the Declaration of Independence was produced.It expressed basic beliefs concerning freedom,equality,democracy,privacy and the relationship between people and government,which were exactly what the philosophy of individualism mostly dealt with at that time.This paper is to exploit the essence of individualism by analyzing the Declaration .The analysis enables us to reconsider its significance to the issue of America human rights and foreign policies. 相似文献
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Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities. 相似文献