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1.
针对基坑变形预测中数据的灰色性和非线性的特点,提出用灰色神经网络组合模型预测基坑变形的新方法.该文将灰色模型与神经网络模型并联构成组合预测模型,融合二者的优点,并结合实例,将灰色模型、神经网络模型和灰色神经网络组合模型的预测结果进行对比分析.结果表明:灰色神经网络组合模型的预测结果更精确,对变形监测的生产实践具有一定的参考意义.  相似文献   

2.
为了预测基坑周围地表道路的沉降,该文结合常州恒生科技园二期建设工程实例,提出了灰色GM(1,1)与神经网络模型组合构成灰色神经网格模型。基于层次分析法,选取建筑物沉降、围护结构顶部水平位移、竖向位移、地下水位作为影响地表道路沉降的主要因素,并将其作为模型的输入因素。研究结果表明,灰色神经网络模型结合三次样条插值建立的组合预测模型,具有较高的预测精度,有利于基坑的预测、预警,有效地保障了基坑施工的安全。  相似文献   

3.
为提高基坑开挖过程中变形监测实时预测的准确性与可靠性,文章结合灰色系统理论,考虑关于监测数据与基坑开挖深度之间的关系,建立离散灰色系统模型,利用该模型对原始沉降数据进行分析预测,并通过实验数据对比分析得出,利用离散灰色系统模型预测的结果与实测数据相吻合,预测精度可靠,且具有一定的参考价值。  相似文献   

4.
准确的深基坑变形预测和控制是当前地下工程监控测量研究领域的热点问题,尤其是深基坑变形的中长期预测,对保障现场人员和财产安全具有重要的预警作用。以某地铁盾构始发竖井深基坑为工程背景,采用滑动平均法(MA)对基坑变形现场实测的地表沉降原始数据进行去噪处理,增加监测数据的权重,然后引入灰色Verhulst模型对去噪后的数据进行中长期拟合预测,最后对比分析灰色GM(1,1)模型、灰色Verhulst模型、滑动平均-灰色Verhulst模型的预测精度。结果表明:滑动平均-灰色Verhulst模型的预测精度较高,适用于基坑中长期变形预测。该结果可为提高类似变形问题的预测精度提供启示作用。  相似文献   

5.
在分析BP神经网络和灰色模型群的变形预测基本原理的基础上,以某基坑为例,分别构建了基于BP神经网络的预测模型、基于灰色模型群的预测模型以及基于BP神经网络模型和灰色模型群的综合预测模型,预测了该基坑开挖过程中产生的变形值。研究表明:综合预测模型的预测精度优于其余两类模型,对于提高基坑的变形预计精度有一定的参考价值。  相似文献   

6.
基坑变形灰色预测预警系统   总被引:15,自引:0,他引:15  
文章从分析基坑位移影响因素和位移特征入手 ,提出了根据现场位移观测值建立灰色预测预警模型的思路 ,并讨论了建模过程。实践证明基坑变形灰色预测系统有较好的精度 ,对指导基坑开挖和支护有积极意义  相似文献   

7.
为了对矿井深部瓦斯涌出量进行预测,介绍了灰色线性回归组合模型的建模方法,以某煤矿相对瓦斯涌出量统计数据为实例,利用灰色线性回归组合模型对其瓦斯涌出量进行预测,通过检验得出模型的精度等级为一级。结果表明:灰色线性回归组合模型可以使传统的灰色GM(1,1)模型不含线性因素的情形得到改善,在预测矿井深部瓦斯涌出量中取得了良好的预测效果,具有一定的实用价值。  相似文献   

8.
地铁基坑水平位移预测分析   总被引:1,自引:0,他引:1  
以某地铁基坑的实测资料为基础,采用灰色系统理论对其水平位移进行了灰色预测.分析结果表明:模型预测值偏大,但其预测结果同样具有较好的精度,并有一定的安全余地.因模型前期预测时序数列是不断更新的,故该模型不能作中长期位移预测.  相似文献   

9.
为了提高在变形监测中数据预测的精度以及它的可靠性,该文提出了基于动态灰色时序模型与神经网络组合的预测方法。根据已有的地铁沉降数据,对地铁隧道结构变形进行数据分析与预测,并与动态灰色模型、动态灰色时序模型进行精度对比。实例证明,该组合模型在地铁隧道结构变形预测中的精度较高。  相似文献   

10.
《煤炭技术》2017,(12):119-120
利用径向基神经网络纠正无偏灰色预测残差,构建了一种径向基无偏灰色组合模型,并利用该组合模型对某矿山瓦斯相对涌出量进行实验仿真。结果表明,该组合模型预测与无偏灰色模型相比,平均绝对误差比RBF神经网络增高,且不受数据波动性影响,能够更好地反映矿山瓦斯相对涌出量的规律,预测准确、可靠。  相似文献   

11.
<正>Market status and future trend of NiMH battery1.Global market of small NiMH battery Global market size of small NiMH batteries declined year on year since 2011.The trend will continue to 2018,at the rate of 5%to 10%annually.Demand for small NiMH batteries will be stable gradually.Many electrical apparatuses are powered by the built-in lithium battery today,which is the main reason for the shrunk market of small NiMH batteries.But,for some products,small NiMH  相似文献   

12.
正September 1-10,2014 Affected by the National Day holiday,rare earth transaction was stagnant and the market showed a weak steady state.As there was no good news for downstream market,some products with flat demand would likely rally slightly for some time to  相似文献   

13.
<正>Developing ecological lighting source The world is facing the big problem of energy shortage today and the contradiction between economy development and environmental protection is worsened.Therefore,people are more likely to choose an ecological light source that is more energy efficient and environmental friendly.The choice provides great opportunity for the development of rare earth optical material industry in China.The concept of green lighting positions rare earth luminescent material as a leading player in illumination market.The light source of both rare earth luminescent lamp and LED lamp is ecological and energy saving.This is why  相似文献   

14.
正Galaxy Magnet announced its financial results for the first half of 2014 on August 14.For the first six months ended on 30 June 2014,Galaxy Magnet achieved operation income of RMB 182.3 million,up8.40% over the same period of 2013,and the net profit attributable to the shareholders of the listed company of 34.02 million yuan,increasing 35.49% over the same period of last year.Stable performance increase was led by development of new customers and application market of magnets.  相似文献   

15.
<正>China has rich rare earth resources.Output of rare earth and steel in China ranks the top first in the world.However,there is still certain distance between the steel produced in China and developed countries from the point of varieties and quality.China still has to import some types of steel.Improving the quality should be emphasiZed in future development of steel industry in China.Rare earth can be used to upgrade traditional steel  相似文献   

16.
正November 21~30,2014Due to weak demand from downstream industries,transactions of rare earth in Chinese domestic market were inactive.It was difficult to sell any rare earth products except for dysprosium oxide and terbium oxide.Suppliers lost confidence in recent market.Demand for rare earth products was soft.Consumers continued to take a wait-and-see attitude.Rare earth export market remained slow.  相似文献   

17.
分析了近年来国内外稀散金属产业的生产、应用、资源与市场状况.铟锡氧化物靶材、砷化镓晶片、锗红外材料、铼高温合金和硒在电解锰及玻璃的应用等已成为稀散金属的主要应用领域.稀散金属的产量快速增长达到历史高位而导致了市场的失衡.以GaInP_2/GaAs/Ge,CIGS和CdTe为代表的非硅系太阳能电池是稀散金属的新兴应用领域,将给稀散金属带来日益增长的需求.  相似文献   

18.
<正>Rare earth luminescent material is one of the most important application sectors of rare earths.China enjoys the exceptional advantage to develop rare earth luminescent material for its abundant rare earth resources.After several decades'endeavor,China's rare earth luminescent material industry,headed by rare earth phosphor for lamp and LED and high efficient rare earth energy-saving light source,has been gradually developed into a scale industry.China has become a major production base of rare earth phosphor for lamps and rare earth  相似文献   

19.
正June 1~10,2014Rare earth market remained weak.Quoted price of rare earth products was similar to that in May.There was no sign of recovery in downstream market.The market of NdFeB magnetic materials and phosphor was depressed.Catalyst,polishing powder and ceramic industries remained inactive.Demand from downstream industry was soft.Consumers purchased on their needs.Suppliers had strong intention to sell.Prices of rare earth products  相似文献   

20.
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