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1.
针对分析露天边坡稳定性的参数的不确定性和不完备性,精确分析方法在表达边坡系统各组成部分之间的非线性关系上有其局限性问题,依据神经网络建立的数学模型,采用神经网络的学习方法,对露天边坡进行稳定性评价。计算结果表明:边坡实际状态和预测结果十分相近,因此运用神经网络模型评价黄土地区边坡的稳定性有较好的适用性,该方法对露天边坡稳定性预测预报具有重要的理论意义和实用价值.  相似文献   

2.
本文将BP神经网络和遗传算法技术应用于边坡的稳定性评价,通过对标准BP算法进行改进,提出了用遗传算法优化神经网络的GA-BP算法,这样既发挥了神经网络的广泛映射能力和遗传算法的全局搜索能力,实现了两者的优势互补,也加快了网络的学习速度,综合提高了整个学习过程中的逼近能力和泛化能力。  相似文献   

3.
黄土边坡稳定性分析的神经网络方法   总被引:4,自引:0,他引:4  
针对黄土边坡稳定分析计算方法繁琐、复杂、精度低等缺陷,应用神经网络理论,提出了黄土边坡稳定性分析的新方法.以14个边坡工程的稳定状况作为学习样本和预测样本,讨论了基于神经网络技术的黄土边坡稳定性分析方法及其有效性.研究表明,神经网络方法具有精度高,收敛速度快,容错能力高等特点,且操作简洁方便,能有效地应用于黄土边坡稳定性分析.  相似文献   

4.
基于遗传算法神经网络集成股票市场预测研究   总被引:3,自引:0,他引:3  
神经网络集成技术能有效地提高神经网络的学习能力和泛化能力,已经成为机器学习和神经计算领域的一个研究热点.本文利用不同的神经网络算法产生神经网络集成个体,以误差平方和最小为准则,用遗传算法动态求解集成个体的非负权重系数,进行最优组合集成建模研究,并以此建立股市预测模型.通过上证指数开盘价、收盘价进行实例分析,计算结果表明该方法相对传统的简单平均集成模型,具有预测精度高、稳定性好,易于操作的特点.  相似文献   

5.
ELM-RBF神经网络的智能优化策略   总被引:3,自引:0,他引:3  
提出了ELM-RBF(extreme learning machine-radial basis function)神经网络的智能优化方法,采用差分进化算法和粒子群优化算法来确定ELM-RBF神经网络中隐层神经元的中心和宽度。仿真结果表明,在具有相同的网络结构前提下,基于智能优化策略的ELM-RBF神经网络学习算法具有更好的泛化能力和较好的鲁棒性。  相似文献   

6.
为了评价边坡的稳定性,利用神经网络对样本进行训练。由于传统的BP神经网络存在不足,利用了自适应步长的BP神经网络和Levenberg-Marquardt法,并与传统的BP神经网络进行比较。结果表明,这两种方法在提高计算速度和泛化能力具有优势,其中自适应步长的优点更加明显。在考察训练样本预测的准确性方面,3种BP网络的结果相近。  相似文献   

7.
边坡稳定性预报的MEP分类预测算法   总被引:1,自引:0,他引:1  
鉴于传统方法和数值分析方法的局限性,引入了密切影响边坡稳定性的若干参数,运用多表达式程序设计方法建立边坡稳定性评价模型.基于已有的边坡事例,对该模型进行训练和自我学习,然后用样本训练后的优化模型对新的土质边坡数据集进行预测评价.数值实验表明:多表达式程序设计算法在建立边坡稳定性评价模型中具有较高的可信度.  相似文献   

8.
随着智慧城市建设的步伐不断加快以及人工智能技术的高速发展,如何利用大数据技术对电气火灾事件实现精准预测已经成为当前火灾预防研究者特别关注的问题.本文设计并实现了基于TensorFlow智能学习系统的LSTM神经网络电气火灾预测算法,对某地区输电线路上的数据进行了分析,通过多次数据迭代和参数调优对模型进行了训练,实验结果表明,基于TensorFlow的LSTM神经网络算法对于电气火灾的预测不仅具有较高的准确度,而且泛化能力强,预测效果明显好于其他学习算法.  相似文献   

9.
综合同伦方法与Levenberg-Marquardt(LM)优化方法,提出了一种新型非线性同伦LM神经网络学习算法以改善现有神经网络学习算法的学习效率,分析了不同类型的过渡函数对神经网络泛化性能的影响.该算法具有稳定性强、收敛性能好的特点.结合工业过程实际要求,将提出的改进算法用于丙烯腈收率神经网络软测量建模并与几种常见建模方法比较,结果表明:基于改进算法的软测量模型具有更高的测量精度和更好的泛化性能,满足现场测量要求.  相似文献   

10.
为了进一步提高教学质量评价准确率,提出一种基于主成分分析(PCA)和学习矢量量化神经网络(LVQ)相结合的教学质量评价模型.使用层次分析法(AHP)建立教学质量评价体系,再用主成分分析提取初始评价指标体系的特征信息,将经过降维处理后的特征信息输入到LVQ神经网络,并对网络模型进行训练和泛化能力测试.实验结果表明,与单一的LVQ和BP神经网络相比,PCA-LVQ网络模型的结构更为简化,学习能力更强,收敛速度更快,评价准确率更高且泛化能力强.  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.
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   

19.
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   

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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