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1.
针对航空发动机多管路布局问题,运用协同进化的思想,结合混沌人工鱼群算法,提出了基于混沌人工鱼群协同进化算法的航空发动机多管路智能布局方法.该方法将每个管路对应一个种群,一方面采用混沌人工鱼群算法使各物种在自己的种群中进行独立进化,另一方面采用合作型协同进化方法对由选取的代表构成的系统模型进行进化以使多管路布局达到全局最优.该算法不仅避免了在管路增多情况下的组合爆炸现象,而且不用考虑布局顺序从整体上优化管路布局.  相似文献   

2.
针对机构综合的非线性方程组求解问题提出了一种改进的微分进化算法.该算法是将方程组转换成一个优化问题,在进化过程中,该算法根据进化情况采用动态参数调整机制提高算法的搜索效率,并且对种群重叠状况进行实时监视,对重叠个体利用混沌搜索策略来进一步提高算法的全局寻优能力.机构综合实例结果分析表明,文中提出的改进微分进化算法高效、且全局寻优能力强.  相似文献   

3.
基于混沌迁移策略的多种群差分进化算法   总被引:1,自引:0,他引:1  
针对差分进化算法全局寻优效率偏低的弱点,提出了一种基于多种群的混沌迁移策略,用以改进常规差分进化算法。该策略通过在多种群并行进化过程中引入混沌迁移序列,引导个体进行种群间的迁移。利用混沌的遍历性和随机性,保证子种群之间能够进行充分高效的信息交换。仿真实验和PID控制参数优化应用表明:该算法具有很强的全局搜索能力,寻优效率高,有效地克服了基本差分算法的早熟收敛问题。  相似文献   

4.
讨论了一个新三维混沌系统的控制与同步问题,首先通过对该混沌系统增加一个具有分段二次函数x|x|形式的非线性反馈控制器,利用它将这个新混沌系统控制到低周期轨道.设计了一种新的非线性反馈控制器,实现该新混沌系统的自同步.数值仿真证明了该方法的有效性.  相似文献   

5.
差分进化算法求解复杂优化问题时,由于进化后期种群多样性降低,算法极易陷入局部最优值无法跳出.论文针对该问题,将差分进化算法和混沌优化方法耦合,构建了混沌差分进化算法.算法利用混沌序列的遍历性和内部迭代的随机性,弥补差分进化算法容易陷入局部最优的缺陷,从而提高算法的搜索性能.对几种典型函数的测试结果表明:混沌差分进化算法的全局搜索性能有了显著提高,能有效避免算法陷入局部最优.因此,与标准差分进化算法和混沌优化算法相比,该算法在求解复杂优化问题时更加可行、有效.  相似文献   

6.
提出一种基于混沌免疫进化算法的1/4汽车主动悬架控制方法.在免疫进化算法的基础上,利用混沌运动的特点,对初始种群混沌初始化,且根据个体评价值对群体进行不同幅度的混沌载波,既可保护优秀个体,又可进行遍历搜索,跳出局部极小值,达到快速寻优的效果.仿真结果表明:与免疫进化控制比较,采用混沌免疫进化控制,汽车的平顺性和安全性得到了更好的改善.  相似文献   

7.
针对基本鲸鱼优化算法在处理复杂全局优化问题时存在解精度低和收敛速度慢等缺点,提出一种收敛因子随进化迭代次数非线性变化的改进鲸鱼优化算法.该算法利用混沌方法替代随机方法初始化种群,使群体具有较好的多样性.受粒子群算法惯性权重启发,设计出一种随进化迭代次数增加而非线性变化的收敛因子更新公式,以平衡算法的全局搜索和局部搜索能力.对当前最优鲸鱼个体执行混沌扰动策略以扩大其搜索范围.选取6个高维标准测试函数进行数值实验,结果表明该算法具有较高的收敛精度和较快的收敛速度.  相似文献   

8.
当前大部分多目标进化算法采用Pareto排序为种群个体指定适应度值;然而随着优化目标个数增加,种群中非支配个体的比例越来越大,造成上述算法的搜索能力迅速下降。针对高维(4个以上)目标优化问题,提出了一种全排序方法;该排序方法与Pareto排序具有一致性,并且能够对非支配解进行比较;因此基于全排序的多目标进化算法不受目标个数增加的影响。为了提高算法的优化效果,设计了一个混沌映射算子,用来周期性地初始化种群,以保证种群的多样性与均匀分布。最后,采用标准测试问题对所提算法与著名的非支配快速排序遗传算法(NSGA2)进行了实验比较。结果表明在高维目标优化问题中,所提算法无论在收敛精度,还是算法运行效率上都高于NSGA2算法。  相似文献   

9.
针对传统WOA算法在迭代寻优前期因种群存在适应度相对较差个体并通过代间信息继承途径而影响新种群优良性与算法寻优性能的问题,提出一种将WOA算法与混沌搜索策略相融合的改进鲸群优化算法(MWOA).该算法在每代寻优过程中以个体适应度值的优劣作为判定准则以识别当前种群的最差个体,通过混沌映射对该最差个体进行位置更新以改善种群的优良性并提高算法的优化性能与寻优效率.实验结果表明,改进算法在基准测试函数实验表现出较强的探索寻优性能、在最小二乘支持向量机的参数优化实验中验证了其较高的寻优效率等.  相似文献   

10.
基于混沌遗传算法的PHEV能量管理策略优化   总被引:1,自引:0,他引:1  
提出了一种新的混沌遗传算法,改进了混沌映射和遗传算法的结合方式,使种群在进化的过程中能够混沌搜索解空间,从而增强遗传算法的遍历性.该算法有效地克服了遗传算法局部收敛的缺陷.在软件ADVISOR2002中,以一辆采用模糊能量管理策略的插电式混合动力电动汽车(Plug-in Hybrid Electrical Vehicle,PHEV)为研究对象,应用该混沌遗传算法对其隶属函数和控制规则进行了优化.仿真结果表明,该算法可以实现对模糊控制器的全局优化.与原模糊控制策略相比,优化后的燃油经济性提高了5.15%,CO排放减少了6.39%.  相似文献   

11.
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.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
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.  相似文献   

13.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

14.
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。  相似文献   

15.
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.  相似文献   

16.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

17.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

18.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

19.
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-  相似文献   

20.
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-  相似文献   

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