面向跑道积冰预警的自主降温装置及性能调控

针对跑道积冰问题,设计以热电制冷器为核心的自主降温装置实现积冰主动预警。数值分析表明装置冷端受跑道小范围气象环境影响,具备非线性特性。为实现装置温度快速响应和精准跟随,提出双回路自抗扰控制(ADRC)方法,设计了面向跑道积冰预警需求的自主降温控制器。仿真结果表明ADRC温控跟随及抗扰性能均优于非线性PID,均方根误差分别为0.654 1和1.152 6。低温实验箱温控性能测试显示,装置在不同的温控指令下ADRC的稳态误差均小于非线性PID,最高为0.04℃;跑道环境下的冰点探测实验表明,装置能够实现跑道冰点探寻功能。该自主降温装置温控性能调控策略满足跑道积冰主动预警之需求。     

基于最小二乘法及信息熵的短期水文预报组合模型的比较

为探讨组合预报中平均加权法的实用性,以三峡流域宜昌站为例,建立了基于最小二乘法和信息熵理论的两种径流组合预报模型,并将组合预报结果与原单一模型的预报结果做了对比,选取具有代表性的预报精度评定指标检验预报精度。结果表明,两种组合预报模型均显著改善了预报精度评定指标,提高了短期水文预报精度,突破了传统单一水文预报模型的局限性,实际应用时可根据预报精度评定的侧重点选择合适的组合预报模型。     

基于经验模态分解与多步预测的最小二乘支持向量机的风速预测

由于风速信号是非线性、非稳定性的动态信号,用传统预测方法难以达到满意效果。为提高预测精度,提出了基于经验模态分解与多步预测的最小二乘支持向量机相结合的方法,对风速时间序列进行建模预测,即首先对风速动态信号进行经验模式分解,将原信号分解为若干个不同特征尺度(频率)的本征模态函数,然后对不同频带的平稳IMF分量分别建立多步预测的最小二乘支持向量机模型,将各分量的预测值等权求和得到最终预测值。实例分析结果表明,与单一的最小二乘支持向量机预测方法相比,经验模态分解与多步预测的最小二乘支持向量机相结合的风速预测方法误差小,可应用于风速预测中。     

基于风速误差校正和ALO-LSSVM的风电功率预测

风资源的随机波动性引起的相位滞后性问题,导致风电功率预测精度不高,尤其是风速变化较快时,滞后性引起的预测误差较大。考虑到风速波动与风功率变化密切相关,提出一种非参数核密度估计和数值天气预报(NWP)相结合的方法,并对预测风速误差进行校正,改善了预测风速的相位滞后性;然后将校正后的风速和风功率作为输入数据进行风电功率预测;采用蚁狮算法(ALO)优化最小二乘支持向量机(LSSVM)参数,从而建立基于风速误差校正和ALO-LSSVM组合的风电功率预测模型。算例结果表明,所提方法风功率预测精度更高。     

激光扫描式焊接坡口信息传感方法

设计了激光扫描式焊接坡口信息传感器。采用高精度激光测距传感器在工件的坡口上方垂直于焊接方向扫描,获取传感器水平位移和距工件距离的数据二维曲线并进行数据预处理。处理后的数据经微分后得到一阶导数和二阶导数曲线,根据导数曲线的特点找出表征工件表面和坡口面的最优点集,应用最小二乘法对最优点集进行直线拟合,求直线的交点得到相应的坡口信息的特征点,从而获得坡口的信息。     

基于二维高密度电阻率数据的二、三维反演对比(英文)

目前高密度电阻率法所采用的数据处理方法主要是将地质结构体视为二度体进行二维处理,因而二维数据资料处理结果只是一种近似解释,其计算精度与反演效果达不到精确反演的要求。设计两种典型的电阻率异常地质体模型,利用有限单元法进行正演计算。为更真实地模拟实测数据并分析二维、三维反演算法对噪声的敏感度,在正演剖面中加入1%的高斯随机误差,然后再分别利用最小二乘法进行高密度电阻率法二维、三维反演。对比二维和三维高密度电阻率法的反演水平切片及垂直切片图可知,三维反演受高斯随机误差的影响更小,反演结果在模型异常位置、形态和电阻率特性反映上都比二维反演的效果更好,与实际地质模型更接近。     

Second-order data obtained from differential pulse voltammetry: Determination of tryptophan at a gold nanoparticles decorated multiwalled carbon nanotube modified glassy carbon electrode

Three-way data obtained from different pulse heights of differential pulse voltammetry (DPV) was analyzed using multivariate curve resolution by alternating least squares (MCR-ALS) algorithm. Differential pulse voltammograms of tryptophan were recorded at a gold nanoparticles decorated multiwalled carbon nanotube modified glassy carbon electrode (GCE/MWCNTs-nanoAu). The determination of tryptophan was performed even in the presence of unexpected electroactive interference(s). Both the simulated and experimental data were non-bilinear. Therefore a potential shift algorithm was used to correct the observed shift in the data. After correction, the data was augmented and MCR-ALS was applied to the augmented data. A relative error of prediction of less than 8% for the determination of the simulated analyte of interest and tryptophan in synthetic samples indicated that the methodology employing voltammetry and second-order calibration could be applied to complex analytical systems.     

Recursion Least Square Method to Study the Fault Diagnosis and Its Model of Hydraulic Equipment

1IntroductionTherearemanykindsofmethodssuchasexpertsystem,neuralnetwork,artificialintelligence,fuzzycontl'OI,greytheoryandsoon,todiagnosethefaultsofhydraulicequipmI3nt.ThediagnosticmethodsarebetweentheblackandwhiteboxtoPrognosticatethefaults.Thereisnocompletemathematicalmodeltoprognosticateanddiagnosethefaultsofthehydraulicequipment.ThepaperlikestheidentificationtheorytobestUdiedfromtheblackboxestothewhiteboxtoestablishthefaultmodelofthehydraulicequipment.Thismodeldocsnotonlyusehydraulicequ…     

30MVA 锰硅合金炉生产指标数理分析

根据30MVA锰硅合金电炉实际生产数据,利用多元线性回归方程与高斯最小二乘法,分析了二次电压、二次电流、三元碱度、硅渣配加量、出铁次数对生产综合指标的影响情况,通过分析,分清了影响因素的主次,并据此提出了电炉的合理操作建议.     

INFLUENCE OF THE DRYING MEDIUM PARAMETERS ON DRYING INDUCED STRESSES

ABSTRACT

A thermomechanical model of drying of capillary-porous materials whose material constants depend on moisture content and temperature is presented in the paper. The finite element method is used for the solution of two-dimensional problem of convective drying of a prismatic bar. The moisture distributions, temperature distributions, drying induced strains and stresses for various drying medium parameters are determined. The effect of these parameters on moisture distribution and in particular on drying induced stresses is discussed.