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1.
针对支持向量机(SVM)参数难以选择和确定的问题,采用一种新式元启发式优化算法——多元宇宙优化算法(MVO).并在传统多元宇宙优化算法(MVO)的基础上针对TDR值下降速度慢而导致旅行距离增加的问题,提出改进多元宇宙优化算法(IMVO),将改进多元宇宙优化算法用于支持向量机的参数优化和选择问题上.使用UCI标准数据库中的数据进行数值仿真实验.研究结果表明:采用改进多元宇宙优化算法优化的支持向量机有较强的寻优性能,稳定性较好.  相似文献   

2.
提出应用一种新的智能优化算法——免疫算法(IA)来求解无功优化问题.该算法模拟了免疫系统的基本原理,具有抗原模式识别及记忆功能,抗体多样性,抗体自适应调节等优点.在分析无功优化的数学模型和免疫算法的特点的基础上,详细研究了用免疫算法求解无功优化问题的实现方法.对IEEE30节点系统进行了仿真计算,并将优化结果与遗传算法(GA)作了比较,结果表明免疫算法(IA)能有效的应用于电力系统无功优化,并有着更好的全局寻优能力及更快的收敛速度.  相似文献   

3.
提出了一种改进的粒子群优化(IPSO)算法以解决可靠性问题.IPSO算法使用3种策略来改进粒子群优化算法(PSO)的速度更新步骤,这有利于提高算法对解空间的开发能力.另外,一种动态调整的惯性权重被引入到速度更新中以平衡IPSO算法的全局搜索和局部搜索.实验结果表明,在解决可靠性问题上,IPSO算法比其他两种粒子群优化算法具有更强的收敛性和稳定性.IPSO算法是解决可靠性问题的一个有效的选择.  相似文献   

4.
提出了最大化系统的频谱效率(SE)和能量效率(EE)两种功率分配方案.EE优化问题用迭代算法求解,首先运用分式规划的方法把优化问题转变成易求解的非分式优化问题,然后运用Dinkelbach算法求得用户节点的最佳功率,再运用一维搜索求得最佳中继放大系数,最后利用迭代算法求得EE最大值.SE优化问题同样用迭代算法求解.仿真结果显示,针对不同目标函数的两种功率分配方案分别提高了系统的EE和SE,同时迭代算法能够快速收敛获得最优解.  相似文献   

5.
模拟植物生长算法(PGSA)是以植物向光性机理(形态素浓度理论)为启发准则的智能优化新算法,具有高效的搜索能力.本研究对PGSA的基本原理进行分析,指出了不同初始生长点的选取会影响该优化算法能否收敛于全局最优解.由此,为提高模拟植物生长算法的全局搜索能力,引入粒子群算法(PSO),提出了新的混合策略(PGSA-PSO混合智能优化算法):先基于粒子群算法的高鲁棒性初选优秀的初始生长点,再基于模拟植物生长算法的高效搜索能力得到最终的全局最优解.算例表明,该混合策略可有效提高模拟植物生长算法的全局搜索能力.最后,利用该混合策略对典型的弦支穹顶结构预应力优化问题进行分析.结果表明,此混合智能优化算法的优化效果显著,在结构优化问题中具有较好的可行性和有效性.  相似文献   

6.
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).  相似文献   

7.
求解全局优化问题的算法通常是在求解区域是有界的假设下进行 ,这仅仅出于实际计算上的考虑[1] ,而在无界区域上求解全局优化问题的算法很少见到[2 ] .非线性方程 (组 )问题已得到大量的研究[3] ,但非线性方程 (组 )问题往往只有局部或半局部收敛算法 ,而具有全局收敛性质的算法则尚未见到 .本文从可计算性角度给出负面的结果 ,阐明无界区域上的整数规划问题 ,非线性方程 (组 )问题 ,连续全局优化问题不是算法可解的 ,即不存在求解这三类问题的算法 .  命题 1 多项式整数规划问题不是算法可解的证明 注意到判定 ( 1 )式是否有整数解等价…  相似文献   

8.
混沌PSO梯级优化调度算法及实现   总被引:2,自引:1,他引:1  
利用切比雪夫(Chebyshev)映射在[-1,1]区间上的遍历性和随机性,提出了一种基于切比雪夫映射的新型混沌粒子群优化(CPSO)算法.该算法在粒子群算法求出的最优解附近进行混沌搜索.提高了混沌粒子群算法的全局优化能力,能有效避免算法容易陷入局部最优以及解决逻辑斯谛(logistic)映射不能在负值区间进行搜索的问题.针对模型中复杂的约束条件,采用分段线性插值函数实现了对目标函数的求解,并通过对采用丰枯电价时三峡梯级水电系统长期优化调度问题的计算及与其他算法的对比,验证了该算法可解决具有复杂约束条件的工程优化问题.  相似文献   

9.
蚁群算法在寻优过程中很容易出现早熟现象而陷入局部最优,同时蚁群算法在构造问题的可行解时,计算复杂度较大.为解决以上问题,将免疫算法和蚁群算法相结合,构成了一种结合免疫机制的蚁群优化算法,并将其用于解决WTA(武器目标分配)问题.通过仿真及与其它多种优化算法对比发现:基于免疫的蚁群优化算法在搜索效率上要高于其它优化算法.  相似文献   

10.
在分析具有同时送货和取货需求的车辆路径问题(VRPSDP)的基础上,建立VRPSDP数学模型,提出一种新的求解VRPSDP问题的蚁群禁忌混合优化算法(ACO-TS),并通过实验验证该算法的有效性和可行性.新算法首先采用蚁群算法产生阶段最优解,然后利用禁忌搜索算法对阶段最优解进一步优化.实验表明,新算法能够高效解决VRPSDP问题,并且具有较好的优化效果.  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.
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.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
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.  相似文献   

14.
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   

15.
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.  相似文献   

16.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

17.
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   

18.
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   

19.
Quality traits in wheat (Triticum aestirum L.) were studied by quantitative trait locus (QTL) analysis in a recombinant inbred line (RIL) population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross (ChSh). Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.  相似文献   

20.
赵英华 《科技信息》2008,(12):219-220
0.Preface China has long been boasting of its colorful and immense culture which comprises of Taoism,Confucianism and Buddhism.The interwoven influence among the religions on Chinese way of thinking,on the nation's behavior in their social life throughout the long history is beyond list.  相似文献   

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