钢铁企业综合技术经济指标的神经网络评价模型研究

利用BP神经网络理论建立技术经济指标评估的数学模型,采用3层神经网络,进行多因素输入建模.通过对模型的训练,使网络的实际输出值与期望输出值的误差均方值最小.经仿真计算证明,该数学模型具有较好的辨识精度.     

基于Elman神经网络的炉卷轧机的轧制力预报

为了改善国内某钢铁厂炉卷轧机的轧制力模型的预报精度,提出将结合热模拟实验建立的传统轧制力模型计算值作为Elman神经网络的一个输入项,将传统数学模型预报的轧制力与实测轧制力的相对误差作为此神经网络输出项的方式构建网络模型,通过大量的在线数据分析,这种将神经网络与传统数学模型相结合的方法明显地改善了轧制力的预报精度。该神经网络模型可为以轧制力为主要控制目标的炉卷轧机的过程自动化系统提供可靠的模型参数。     

铜闪速熔炼过程操作参数预测模型及应用

基于某厂实际铜闪速熔炼工艺和控制过程,对神经网络模型在铜闪速熔炼过程在线控制进行了研究。在分析影响溶剂率、熔炼氧单耗、反应塔总风量操作参数因素的基础上,提出一种基于BP神经网络的操作参数的预测方法,分别建立了输入向量只包含主要元素和考虑杂质元素的BP神经网络模型。网络的训练和测试结果表明,两种神经网络的输出值与实际值的最大相对误差均小于1.0%,输出值与实际样本值吻合得较好,模型输入参数中包括杂质元素时具有更高的计算精度。     

基于人工神经网络的Ce/TiO2纳米复合体抗菌性能的预测模型

在正交设计的基础上,采用浸渍法制备了Ce/TiO2纳米复合体.根据BP人工神经网络算法原理,建立了Ce/TiO2纳米复合体制备工艺参数与抗菌性能之间关系的BP神经网络预测模型,并将预测值与实验数据进行了比较,其训练样本的输出值最大误差为3.18%,平均误差为0.4%.对经过训练后的模型进行了验证,其测试样本的输出值最大误差为6.31%,平均误差为4.06%,与实验值吻合良好.结果表明,所建立的BP神经网络模型具有较高的预测精度,用于Ce/TiO2纳米复合体的抗菌性能预测是可行的.     

遗传神经网络在平整轧制力预报中的应用

研究了平整轧制力设定的人工智能实现方法,采用改进的混合GA－BP遗传神经网络算法建立了平整轧制力预报模型。传统数学模型与遗传神经网络方法获得的统计数据表明,该遗传神经网络方法所得预报值优于传统方法。     

专家系统+神经网络预估补偿智能控制在电弧炉电极控制中的应用

介绍一种基于专家系统+神经网络预估补偿的电弧炉电极自适应控制.在电弧炉调节系统中采用专家系统将各种影响电弧炉运行的各种因素总结成判据和控制规律并对其进行控制,通过神经网络预估控制对象的状态,进而对控制输出补偿并控制实际对象,利用改进的DBD算法动态修改神经网络权值作为自适应方法,使电弧炉电极调节系统较好地适应负荷和外扰的变化,以获得满意的控制效果.     

上市医药公司财务绩效评价——基于DEA-BP模型的分析

本文首先选取18家上市医药公司的相关财务指标,利用数据包络分析法测度效率,然后将计算出的效率值作为输出变量,利用BP神经网络进行学习,建立预测模型,取得了较高的精度.     

上市医药公司财务绩效评价——基于DEA-BP模型的分析

本文首先选取18家上市医药公司的相关财务指标,利用数据包络分析法测度效率,然后将计算出的效率值作为输出变量,利用BP神经网络进行学习,建立预测模型,取得了较高的精度.     

基于遗传算法优化BP神经网络的小球藻生长模型的建立与应用

[目的]探讨用遗传算法优化BP 神经网络对小球藻生长模型的建立与应用.[方法]使用遗传算法对BP 神经网络的权值和阈值进行优化,并使用该网络模型,以小球藻培养时间和残余葡萄糖为输入,菌体光密度值(OD<,680>)为输出,对小球藻在500 L多功能生物反应器中的生长情况进行了建模,还探讨了该模型的应用情况.[结果]经过遗传算法优化的BP 神经网络,其泛化值的误差平方和比BP神经网络的小,因而预测值更加接近实际值.t 检验表明,所建立的模型是可信的.验证表明,该模型具有良好的拟合度,能够很好地描述在500 L 多功能生物反应器中培齐的小球藻的生物量(OD<,680>)与残余葡萄糖和培养时间之间的关系.[结论]所建立的模型可用于试验结果的预测,对小球藻的培养控制具有指导意义.     

基于人工神经网络的热连轧参数预测模型

将BP神经网络的思想用于预测热连轧参数，研究并建立了基于BP神经网络的预测控制数学模型。以热连轧精轧自然宽展值为例，现场实测数据仿真验证表明，该模型明显优于传统的数学预测模型，具有很高的预测精度。     

Kinematics of the pelvic girdle and the thoracic and lumbar segments in the course of the lateral inclinations and rotations of the spine

Physiological displacements of the trunk are the addition of these of the pelvic girdle and thoracic and lumbar spine segments. For a long time (3), this conjunction had been noticed but without numbered precisions. The purpose of this communication is to appreciate quantitatively, from a series of 16 subjects, the respective share of each components during lateral bending movements in the frontal plan and movements of rotation in the transverse plan. It results from this work that the pelvic girdle presents as reduced amplitude (4 degrees) in lateral bending on the other hand, displacement predominate to the level of thoracic spine (50 degrees). In rotation pelvic displacements are very important (30 degrees), while the spine so thoracic that lumbar has a weak participation (inferior to 5 degrees). Moderated abduction of hips increases by significant manner the motility of the pelvic girdle.     

Characteristics of the sympathetic innervation of the nictitating membrane and of the vasculature of the nose and tongue of the cat

Vasomotor responses from the nasal mucosa and tongue, and contractions of the nictitating membrane, were recorded on stimulation of the cervical sympathetic or internal carotid nerves. Preganglionic sympathetic nerve fibres which elicited a membrane response possessed a lower threshold than those which evoked nasal vasoconstriction, while the latter displayed a lower threshold than fibres which evoked tongue vasoconstriction. The sympathetic vasodilator fibres to the tongue whose activity was revealed after alpha-receptor blockade, had a similar threshold to the vasoconstrictor fibres. Membrane contraction, nasal vasoconstriction and occasionally tongue vasoconstriction could be evoked by stimulating the internal carotid nerve. The postganglionic fibres innervating the nasal mucosa had a similar threshold to those of the nictitating membrane, which may indicate that there are small myelinated fibres innervating the mucosa. The preganglionic compound nerve action potential had four major components, S1-S4. S1, S2 and usually S3 fibres were associated with membrane contraction; S2, S3 and sometimes S1 fibres were associated with nasal vasoconstriction; and S3, usually S2 and occasionally S1 fibres were associated with vasoconstriction in the tongue. It is concluded that each of these three groups of nerve fibres, but not S4 fibres, may include fibres associated functionally with the three effectors. There was a considerable difference between the relative amplitude of the responses of the three effectors elicited by stimulation of the cervical sympathetic nerve at frequencies between 0.2 and 2 Hz. Vasoconstrictor responses were relatively larger than membrane contractions suggesting differences in the mechanisms of neurotransmission at the neuroeffector junctions.     

Design and analysis of the tunnel connecting the beamcorridor and the spectrum hall of the CSNS

There is a tunnel connecting the beamcorridor and the target station in the spectrum hall in the CSNS project. The length of the tunnel is about 20 m. The shielding design of the tunnel is very significant for the persons working in the spectrum hall beca     

江西省降水集中期及其期间降水量的变化特征及趋势分析

根据江西省地方标准中有关降水集中期的定义,统计1971～2008年4～9月的降水集中期,并用季节性Kendall检验方法做趋势分析.结果表明,1971～2008年4～9月期间,6～8月是降水集中期及其期间雨量较多的月份,4、5、9月是降水集中期及其期间雨量较少的月份.随时间变化,全省6～8月降水集中期及其雨量呈可能增多趋势,4、5、9月呈可能下降趋势.     

优化焊缝金相组织 充分发挥石油用 ERW管的技术经济优势

P2ERW管代替无缝管,用于石油开采所用油管和套管的关键,是确保焊缝的高质量。它不仅需要具备先进的技术装备和完善的检测手段,更需要发挥金相检验对优化各项工艺参数的指导作用,才能从根本上掌握生产优质ERW石油用管的规律。