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长壁孤岛工作面煤岩冲击危险性区域多参量预测 被引量:27
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作者 王宏伟 姜耀东 +1 位作者 杨忠东 刘帅 《煤炭学报》 EI CAS CSCD 北大核心 2012年第11期1790-1795,共6页
以开滦集团唐山矿某孤岛工作面地质条件为背景,通过巷道表面位移、顶板离层、工作面回采过程中的电磁辐射等现场监测结果分析了巷道顶板受工作面动压影响剧烈的范围,确定了孤岛工作面发生冲击失稳的危险区域。监测结果显示:孤岛工作面... 以开滦集团唐山矿某孤岛工作面地质条件为背景,通过巷道表面位移、顶板离层、工作面回采过程中的电磁辐射等现场监测结果分析了巷道顶板受工作面动压影响剧烈的范围,确定了孤岛工作面发生冲击失稳的危险区域。监测结果显示:孤岛工作面顶板在距离工作面前方30 m时开始受采动影响频繁,当到达工作面前方10 m范围内时,顶板活动加剧,直至顶板垮落。顶板大面积来压和剧烈的顶板活动是本文作为孤岛工作面冲击地压发生的前兆,由此可确定在工作面前方7.5~10.0 m是孤岛工作面最容易发生冲击失稳的区域。 展开更多
关键词 孤岛工作面 冲击地压 参量预测 煤岩体 电磁辐射
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光面爆破效果参量预测的投影寻踪回归模型及应用 被引量:8
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作者 李启月 徐敏 +1 位作者 董陇军 钱守一 《中南大学学报(自然科学版)》 EI CAS CSCD 北大核心 2012年第10期3976-3981,共6页
基于投影寻踪回归理论,选取炮眼密集系数、最小抵抗线、装药量、炮眼深度、抗压强度和泊松比6个因素为判别指标,建立光面爆破炮眼利用率、超挖量和半眼率的预测模型。将该方法应用于某矿巷道掘进光面爆破效果预测问题中,对现场实测的24... 基于投影寻踪回归理论,选取炮眼密集系数、最小抵抗线、装药量、炮眼深度、抗压强度和泊松比6个因素为判别指标,建立光面爆破炮眼利用率、超挖量和半眼率的预测模型。将该方法应用于某矿巷道掘进光面爆破效果预测问题中,对现场实测的24组数据进行训练和检验,用另外4组现场数据作为预测样本进行测试。预测结果与实测情况较吻合。比较BP神经网络和投影寻踪回归2种方法对光面爆破炮孔利用率的预测结果,发现后者比前者预测结果更接近实际。以上研究表明:该方法回判估计性能良好,判别精度高,是一种预测光面爆破效果的有效方法,可以在实际工程中推广应用。 展开更多
关键词 光面爆破 爆破效果评价 投影寻踪回归 参量预测
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基于遗传BP神经网络的煤矿爆破振动特征参量预测 被引量:8
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作者 张士科 方宏远 耿勇强 《煤炭科学技术》 CAS 北大核心 2018年第9期133-139,共7页
为了解决矿区爆破振动产生的危害大、影响因素多、特征参量监测结果离散和计算非线性的问题,通过建立基于遗传算法优化BP神经网络预测模型来拟合煤矿爆破振动参数与特征参量之间的非线性关系,并采用该模型对煤矿爆破振动特征参量进行了... 为了解决矿区爆破振动产生的危害大、影响因素多、特征参量监测结果离散和计算非线性的问题,通过建立基于遗传算法优化BP神经网络预测模型来拟合煤矿爆破振动参数与特征参量之间的非线性关系,并采用该模型对煤矿爆破振动特征参量进行了准确的预测。研究结果表明:在实际工程中,GA-BP神经网络模型对确定不容易测量的爆破振动特征参量能有效预测,同时又能节约大量人力和财力;GA-BP神经网络预测模型较经验公式、BP神经网络预测模型有更强的解决复杂非线性问题能力,其预测值与实际值的相对误差在10%以内,不易陷入局部极小值,稳定性更好,平均预测精度较高;从使用的样本数量可知该模型可为小样本、多因素影响参数预测问题提供一种切实有效的方法,且工作量小而灵活,适用性广泛。 展开更多
关键词 遗传算法 BP神经网络 爆破振动 特征参量预测 煤矿爆破参数
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实时参量预测模型及其分析
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作者 陈传波 刘广宇 《湖北工学院学报》 2001年第4期25-28,共4页
从实时系统的随机性和规律性出发,提出了3组共9个实际系统中重要参数的预测模型.对一类实时系统进行了分析,并将其抽象化.对模型的有效性进行了理论分析,从一个实际系统的初步实验中也证明了模型的预测能力和效串.
关键词 时间序列 实时参量预测模型 样本空间 实时分析 预测能力 企业信息管理 趋势模型
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多参量综合指标冲击地压预测技术研究 被引量:12
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作者 贾宝新 陈浩 +1 位作者 潘一山 陈扬 《防灾减灾工程学报》 CSCD 北大核心 2019年第2期330-337,共8页
提出了"全局-区域-局部"多参量综合指标冲击地压预测技术,多种预测方法相互协调与配合、优势互补,形成空间上层次化全方位的预测体系,可极大提高冲击地压预测准确性。结合老虎台矿冲击地压发生机理与影响因素,提出利用微震法... 提出了"全局-区域-局部"多参量综合指标冲击地压预测技术,多种预测方法相互协调与配合、优势互补,形成空间上层次化全方位的预测体系,可极大提高冲击地压预测准确性。结合老虎台矿冲击地压发生机理与影响因素,提出利用微震法对采区全局范围内微震事件进行实时监测,划分具有冲击危险区域,全局范围预测冲击地压;利用电磁辐射法监测工作面及巷道近场围岩的应力场和煤岩变形破坏变化状况,确定近场围岩高冲击危险区域,局部范围预测冲击地压;采用矿压监测法和钻屑法对确定具有冲击危险的区域进行重点监测,判断冲击危险程度,对采取防治措施后的防冲效果进行检测;采用采空区气体分析法预测电磁辐射法和矿压观测法等无法监测到的采空区的冲击地压。实践证明:全局-区域-局部"多参量综合指标预测技术的各种预测方法在功能上表现出明显的互补特征,在老虎台矿的冲击地压预报中取得良好效果。 展开更多
关键词 冲击地压 参量预测 电磁辐射 微震 钻屑法
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基于集成模型的煤炭价格多步预测研究 被引量:2
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作者 郝伟 边萌春 《煤炭工程》 北大核心 2023年第8期187-192,共6页
煤炭价格的准确预测对化解能源价格风险有着重要意义,针对煤炭价格预测的问题,开展了基于集成模型的煤炭价格多步预测研究。本研究分析了影响煤炭价格的主控因素,并建立了数据集;将粒子群优化算法(Particle swarm optimization,PSO)和... 煤炭价格的准确预测对化解能源价格风险有着重要意义,针对煤炭价格预测的问题,开展了基于集成模型的煤炭价格多步预测研究。本研究分析了影响煤炭价格的主控因素,并建立了数据集;将粒子群优化算法(Particle swarm optimization,PSO)和长短期记忆模型(Long Short-Term Memory,LSTM)有效集成,建立了一种基于PSO-LSTM的多参量多步预测模型。利用多参量多步预测模型调用数据集进行了曹妃甸港煤炭价格预测,结果表明:基于PSO-LSTM的多参量多步预测模型预测效果优于基于BP、LSTM的预测模型;其预测价格与实际价格的MAPE、R2值分别为0.025、0.908,能够为煤炭市场的科学管控提供帮助。 展开更多
关键词 集成模型 煤炭价格预测 参量多步预测模型 LSTM PSO
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120°E磁赤道上空电离层电子浓度总含量的混沌特性分析及非线性预测初探 被引量:6
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作者 柯璇 万卫星 宁百齐 《地球物理学报》 SCIE EI CAS CSCD 北大核心 2006年第5期1243-1249,共7页
本文利用120°E磁赤道上空电离层TEC1996~2004年的观测数据讨论电离层TEC参量的混沌特性,并探讨利用混沌理论对电离层参量进行预报的可能性.实际计算表明,在指定经纬度的TEC时序数据中存在混沌特性,其关联维数为3.6092,李雅... 本文利用120°E磁赤道上空电离层TEC1996~2004年的观测数据讨论电离层TEC参量的混沌特性,并探讨利用混沌理论对电离层参量进行预报的可能性.实际计算表明,在指定经纬度的TEC时序数据中存在混沌特性,其关联维数为3.6092,李雅普诺夫指数为0.3369.采用混沌“加权一阶局域法”进行预测较为成功.对预测误差分析表明,预测点在1~144之间误差相对较小,标准差约为7.6438TECU,相关系数约为0.9172. 展开更多
关键词 电离层TEC 混沌特性 电离层参量预测 加权一阶局域法
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高速公路隧道通风系统的多参量模糊控制研究 被引量:6
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作者 张晓松 金涛 林东 《重庆交通大学学报(自然科学版)》 CAS 北大核心 2016年第4期20-24,共5页
为解决隧道通风系统能耗较高、智能化程度较低的问题,将隧道烟雾浓度、车流量、风速等多种数据作为参量,预测未来多个连续时刻的烟雾浓度,并以预测结果序列的变化程度及趋势为依据,采用模糊控制方法对隧道通风实现智能化提前控制。通过... 为解决隧道通风系统能耗较高、智能化程度较低的问题,将隧道烟雾浓度、车流量、风速等多种数据作为参量,预测未来多个连续时刻的烟雾浓度,并以预测结果序列的变化程度及趋势为依据,采用模糊控制方法对隧道通风实现智能化提前控制。通过仿真实验证明,与分档控制方法相比,该方法能够根据烟雾浓度变化趋势而调整风机开启数量,避免了因个别采样点的影响而频繁启停风机,有利于延长风机寿命。由于根据预测结果对风机进行了提前控制,在更好地改善隧道环境的同时,缩短了风机开启的总时长,节约能源,降低隧道运营成本。 展开更多
关键词 隧道工程 智能交通 隧道通风 模糊控制 风机控制 参量多步预测
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Analysis of Physical Quantities and Radar Parameters about Hail Shooting and Heavy Convective Rainfall
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作者 陈金敏 刁秀广 《Agricultural Science & Technology》 CAS 2012年第11期2434-2437,2441,共5页
[Objective] The paper is to analyze physical quantities and radar parameter of hail shooting and heavy convective rainfall weather. [Method] Using radar data of Jinan station during 2002 and 2008, combined with soundi... [Objective] The paper is to analyze physical quantities and radar parameter of hail shooting and heavy convective rainfall weather. [Method] Using radar data of Jinan station during 2002 and 2008, combined with sounding data, the physical quantities and radar parameter of hail shooting and heavy convective rainfall weather are compared and analyzed. [Result] The smaller Sl is conducive to the generation of hail weather. When K〉 35 ~C, the probability for occurrence of heavy rainfall weather is significantly increased; when K〈20 ^(3, the probability for occurrence of heavy rainfall weather is significantly decreased. When CAPE value is greater than 1 500 J/KG, the probability for occurrence of hail weather is significantly decreased, while the probability for occurrence of heavy rainfall weather is significantly in- creased. The possibility for occurrence of hail monomer is small when the wind shear is less than 5 m/s; and it is large while wind shear is greater than 20 m/s. The radar forecasting indexes of hail monomer is as follows: VIL value reaches 35 kg/m2 (May), 43 kg/m2 (June and July), the monomer height is greater than 9 km, the maximum reflectivity factor is larger than 60 dBz, strong center height reaches 3.3 km (May), 4.3 km (June) and 5.5 km (July); VlL value of heavy rainfall monomer generally is below 25 kg/m2. [Conclusion] The paper provides basis form prediction of hail and heavy rainfall. 展开更多
关键词 HAIL Heavy convective rainfall VIL Weather radar parameter
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Parameter selection in time series prediction based on nu-support vector regression
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作者 胡亮 Che Xilong 《High Technology Letters》 EI CAS 2009年第4期337-342,共6页
The theory of nu-support vector regression (Nu-SVR) is employed in modeling time series variationfor prediction. In order to avoid prediction performance degradation caused by improper parameters, themethod of paralle... The theory of nu-support vector regression (Nu-SVR) is employed in modeling time series variationfor prediction. In order to avoid prediction performance degradation caused by improper parameters, themethod of parallel multidimensional step search (PMSS) is proposed for users to select best parameters intraining support vector machine to get a prediction model. A series of tests are performed to evaluate themodeling mechanism and prediction results indicate that Nu-SVR models can reflect the variation tendencyof time series with low prediction error on both familiar and unfamiliar data. Statistical analysis is alsoemployed to verify the optimization performance of PMSS algorithm and comparative results indicate thattraining error can take the minimum over the interval around planar data point corresponding to selectedparameters. Moreover, the introduction of parallelization can remarkably speed up the optimizing procedure. 展开更多
关键词 parameter selection time series prediction nu-support vector regression (Nu-SVR) parallel multidimensional step search (PMSS)
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Prediction of the Maximum Flow by the Model SASIS: Sensibility to the Empirical Parameters of the Shape of the Furrow
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作者 Roberto Vieira Pordeus Carlos Alberto Vieira Azevedo +3 位作者 Val6ria Ingrith Almeida Lima Silvanete SeverinoSilva Gleidson Vieira Marques Jose Dantas Neto 《Journal of Environmental Science and Engineering(B)》 2012年第3期433-440,共8页
The model developed in this research presents effective mechanisms in simulations of a discharge strip understood between the minimum and the maximum allowable values, aiming to determine the relationship between disc... The model developed in this research presents effective mechanisms in simulations of a discharge strip understood between the minimum and the maximum allowable values, aiming to determine the relationship between discharge and water application efficiency, deep percolation and runoff rates, and consequently to optimize the performance of the furrow irrigation systems with continuous flow. The flow applied in each furrow must be adapted to the length, to the field slope and to the nature of the ground. The authors studied the maximum non erosive flow (Q,,,~), in function of parameters obtained from the dimensions of the furrow, being Pl and/92, respectively, the linear and exponential parameters of the potential functions that described the relationship between the area of the cross section of flow (or wetted perimeter) and height of flow; in this way, the multiplicative effect of,01 on the area of the cross section of flow is linear, while ,02 is exponential. It verified a conjugated effect of,or and p20n the value of Q,,~. The results of this research point out for the importance of having an estimate of the parameters of the geometry of the cross section of flow (,01 and ,02) the most precise as possible, being known that the dimensions of this section can result in impracticable values of Qmax, outside of the acceptable strip in the literature, that is from 1.2 to 4.0 L.sl. This sensibility analysis was also of great benefit to create an interface in the software SASIS, capable to guide the user of this tool in the input of appropriate values for ,01 and P2 to the process of simulation of the irrigation for furrow with continuous flow and of the optimization of its performance. 展开更多
关键词 Furrow irrigation SIMULATION optimization.
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Partial functional linear quantile regression 被引量:4
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作者 TANG QingGuo CHENG LongSheng 《Science China Mathematics》 SCIE 2014年第12期2589-2608,共20页
This paper studies estimation in partial functional linear quantile regression in which the dependent variable is related to both a vector of finite length and a function-valued random variable as predictor variables.... This paper studies estimation in partial functional linear quantile regression in which the dependent variable is related to both a vector of finite length and a function-valued random variable as predictor variables. The slope function is estimated by the functional principal component basis. The asymptotic distribution of the estimator of the vector of slope parameters is derived and the global convergence rate of the quantile estimator of unknown slope function is established under suitable norm. It is showed that this rate is optirnal in a minimax sense under some smoothness assumptions on the covariance kernel of the covariate and the slope function. The convergence rate of the mean squared prediction error for the proposed estimators is also established. Finite sample properties of our procedures are studied through Monte Carlo simulations. A real data example about Berkeley growth data is used to illustrate our proposed methodology. 展开更多
关键词 partial functional linear quantile regression quantile estimator functional principal coraponent analysis convergence rate
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Effect of triple-phase contact line on contact angle hysteresis 被引量:4
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作者 YU Yang WU Qun +1 位作者 ZHANG Kai JI BaoHua 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2012年第6期1045-1050,共6页
Recent studies have shown that the triple-phase contact line has critical effect on the contact angle hysteresis of surfaces.In this study,patterned surfaces with various surface structures of different area fractions... Recent studies have shown that the triple-phase contact line has critical effect on the contact angle hysteresis of surfaces.In this study,patterned surfaces with various surface structures of different area fractions were prepared by electron etching on a silicon wafer.The advancing angle,receding angle and hysteresis angle of these surfaces were measured.Our experimental results showed that while the geometry of microstructure and contact line have a minor effect on the advancing angle,they have a significant effect on the receding angle and thus the hysteresis angle.We have shown that the effect of microstructure and the contact line can be described by a quantitative parameter termed the triple-phase line ratio.The theoretical predictions were in good agreement with our experimental results. 展开更多
关键词 contact angle hysteresis receding angle surface microstructure area fraction contact line ratio WETTING
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Preoperative determination of tibial nail length: An anthropometric study 被引量:1
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作者 Renjit Thomas Issac Hitesh Gopalan +3 位作者 Mathew Abraham Cherian John Sujith Mathew Issac Diju Jacob 《Chinese Journal of Traumatology》 CAS CSCD 2016年第3期151-155,共5页
Objective: To assess the correlation between five anthropometric parameters and the distance from tibial tuberosity to medial malleolus in 100 volunteers. Methods: Six anthropometric parameters were measured in 50 m... Objective: To assess the correlation between five anthropometric parameters and the distance from tibial tuberosity to medial malleolus in 100 volunteers. Methods: Six anthropometric parameters were measured in 50 male and 50 female medical students using a metallic scale: medial knee joint line to ankle joint line (K-A), medial knee joint line to medial malleolus (K-MM), tibial tuberosity to ankle joint (TT-A), tibial tuberosity to medial malleolus (TT- MM), olecranon to 5th metacarpal head (O-MH) and body height (BH). Nail size predicted based upon Tr-MM measurement was chosen as ideal nail size. A constant was derived for each of the six anthropometric parameters which was either added or subtracted to each measurement to derive nail size. A regression equation was applied to BH measurements. Nail sizes calculated were compared with that obtained from TI'-MM measurement and accuracy was evaluated. Accuracy of O-MH and BH regression equations recommended by other authors were calculated in our data. Results: Adding 11 mm to Tr-A distance had highest accuracy (81%) and correlation (0.966) in predicting nails correctly. Subtracting 33 mm from K-MM measurement and 25 mm from K-A distance derived accurate sizes in 69% and 76% respectively. Adding 6 mm to O-MH distance had a poor accuracy of 51%. Nail size prediction based upon body height regression equation derived correct nail sizes in only 34% of the cases. Regression equation analysis by other authors based on O-MH and BH distances yielded correct sizes in 11% and 5% of the cases respectively. Conclusion: TT-A, K-A and K-MM measurements can be used simultaneously to increase accuracy of nail size prediction. This method would be helpful in determining nail size preoperatively especially when one anatomic landmark is difficult to palpate. 展开更多
关键词 Preoperative periodTibial fracturesBone nailsHuman engineering
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