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关键词

不确定性评估 2

参数估计 2

工艺参数 2

海底隧道 2

设计参数 2

2R-1C模型;嵌入式系统;参数估计;非迭代方法;二次型 1

Arrhenius模型 1

CP);符号间干扰(inter symbol interference, ISI);载波间干扰(inter carrier interference 1

HY-2 卫星 1

ICI);最大似然估计(maximum likelihood estimation 1

LS算法 1

MLE) 1

OFDM 1

OFDM);快速傅立叶变换(Fast Fourier transform, FFT);循环前缀(cyclic prefix 1

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SWAT模型 1

S型钢丝研制 1

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Estimation of relations among hysteretic response measures and design parameters for RC rectangular shear

A. ARAB, Ma. R. BANAN, Mo. R. BANAN, S. FARHADI

《结构与土木工程前沿(英文)》 2018年 第12卷 第1期   页码 3-15 doi: 10.1007/s11709-017-0418-6

摘要: Seismic design of RC structures requires estimation of structural member behavioral measures as functions of design parameters. In this study, the relations among cyclic behavioral measures and design parameters have been investigated for rectangular RC shear walls using numerical simulations calibrated based on the published laboratory tests. The OpenSEES numerical simulations modeling of plastic hinge hysteretic behavior of RC shear walls and estimation of empirical relations among wall hysteretic indices and design parameters are presented. The principal design parameters considered were wall dimensions, axial force, reinforcement ratios, and end-element design parameters. The estimated hysteretic response measures are wall effective stiffness, yield and ultimate curvatures, plastic moment capacity, yield and ultimate displacements, flexural shear capacity, and dissipated energy. Using results of numerous analyses, the empirical relations among wall cyclic behavioral measures and design parameters are developed and their accuracy is investigated.

关键词: RC wall hysteretic measures     RC wall design parameters     empirical relations     numerical simulations     RC rectangular wall plastic hinge    

Dynamic characteristics and improved MPPT control of PV generator

Houda BRAHMI, Rachid DHIFAOUI

《能源前沿(英文)》 2013年 第7卷 第3期   页码 342-350 doi: 10.1007/s11708-013-0242-1

摘要: This paper presents a mathematical model of photovoltaic (PV) module and gives a strategy to calculate online the maximum power point (MPP). The variation of series and shunt resistor are taken into account in the model and are dynamically identified using the Newton-Raphson algorithm. The effectiveness of the proposed model is verified by laboratory experiments obtained by implementing the model on the dSPACE DS1104 board.

关键词: modeling of photovoltaic (PV) generator     maximum power point tracking (MPPT)     estimation parameters     real time controller    

基于机器学习算法的模型参数区域化方法在无测站流域径流模拟中的应用 Article

吴厚发, 张建云, 鲍振鑫, 王国庆, 王文圣, 杨艳青, 王婕

《工程(英文)》 2023年 第28卷 第9期   页码 93-104 doi: 10.1016/j.eng.2021.12.014

摘要:

模型参数估计是无测站流域径流模拟中需要解决的关键问题。参数区域化是应用最广泛的方法,但模型参数与流域特征间的非线性关系是参数区域化的主要障碍。本文以黄淮海流域内38个小流域为研究对象,进行了径流模拟研究,纳什效率系数(NSE)、决定系数(R2)和百分比偏差(PBIAS)的统计结果表明SWAT模型在各流域径流模拟中具有良好的性能。利用与气候、土壤、植被和地形相关的9个指标来表示与水文过程相关的流域特征。采用6种回归模型分析SWAT模型参数与流域特征之间的定量关系,包括:线性回归方程(LR)、支持向量回归(SVR)、随机森林(RF)、K近邻(kNN)、决策树(DT)和径向基函数(RBF)。首先,将38个流域依次假定为无测站流域。然后,利用其余37个供体流域构建拟合参数的回归模型,估算目标流域的模型参数,进行径流模拟。此外,本文也将基于相似性的区域化方法与基于回归分析的方法进行了对比。结果表明:基于支持向量回归(SVR)的区域化方法估计模型参数时径流模拟精度高。与传统的线性回归方法相比,机器学习算法处理非线性关系的能力突出,因而提高了无测站流域径流模拟的精度。不同区域化方法在湿润地区的表现比较接近,而机器学习算法的优势在干旱区更为明显。当研究区内含有嵌套流域时,由于流域密度高、空间距离短,此时采用基于相似性的区域化方法最好。研究结论可为无测站流域的洪水预报和水资源规划提高参考。

关键词: 参数估计     无测站流域     区域化方法     机器学习算法     SWAT模型    

Intelligent algorithm for optimal meter placement and bus voltage estimation in ring main distribution

L. RAMESH, N. CHAKRABORTY, S. P. CHOWDHURY

《能源前沿(英文)》 2012年 第6卷 第1期   页码 47-56 doi: 10.1007/s11708-011-0159-5

摘要: The advancement in power distribution system poses a great challenge to power engineering researchers on how to best monitor and estimate the state of the distribution network. This paper is executed in two stage processes. The first stage is to identify the optimal location for installation of monitoring instrument with minimal investment cost. The second stage is to estimate the bus voltage magnitude, where real time measurement is conducted and measured through identified meter location which is more essential for decision making in distribution supervisory control and data acquisition system (DSCADA). The hybrid intelligent technique is applied to execute the above two algorithms. The algorithms are tested with institute of electrical and electronics engineers (IEEE) and Tamil Nadu electricity board (TNEB) benchmark systems. The simulated results proves that the swarm tuned artificial neural network (ANN) estimator is best suited for accurate estimation of voltage with different noise levels.

关键词: artificial intelligence     power distribution control     state estimation    

Inverse identification of the mechanical parameters of a pipeline hoop and analysis of the effect of

Ye GAO, Wei SUN

《机械工程前沿(英文)》 2019年 第14卷 第3期   页码 358-368 doi: 10.1007/s11465-019-0539-9

摘要: To create a dynamic model of a pipeline system effectively and analyze its vibration characteristics, the mechanical characteristic parameters of the pipeline hoop, such as support stiffness and damping under dynamic load, must be obtained. In this study, an inverse method was developed by utilizing measured vibration data to identify the support stiffness and damping of a hoop. The procedure of identifying such parameters was described based on the measured natural frequencies and amplitudes of the frequency response functions (FRFs) of a pipeline system supported by two hoops. A dynamic model of the pipe-hoop system was built with the finite element method, and the formulas for solving the FRF of the pipeline system were provided. On the premise of selecting initial values reasonably, an inverse identification algorithm based on sensitivity analysis was proposed. A case study was performed, and the mechanical parameters of the hoop were identified using the proposed method. After introducing the identified values into the analysis model, the reliability of the identification results was validated by comparing the predicted and measured FRFs of the pipeline. Then, the developed method was used to identify the support stiffness and damping of the pipeline hoop under different preloads of the bolts. The influence of preload was also discussed. Results indicated that the support stiffness and damping of the hoop exhibited frequency-dependent characteristics. When the preloads of the bolts increased, the support stiffness increased, whereas the support damping decreased.

关键词: inverse identification     pipeline hoop     frequency response function     mechanical parameters     preload    

An operating state estimation model for integrated energy systems based on distributed solution

Dengji ZHOU, Shixi MA, Dawen HUANG, Huisheng ZHANG, Shilie WENG

《能源前沿(英文)》 2020年 第14卷 第4期   页码 801-816 doi: 10.1007/s11708-020-0687-y

摘要: In view of the disadvantages of the traditional energy supply systems, such as separate planning, separate design, independent operating mode, and the increasingly prominent nonlinear coupling between various sub-systems, the production, transmission, storage and consumption of multiple energy sources are coordinated and optimized by the integrated energy system, which improves energy and infrastructure utilization, promotes renewable energy consumption, and ensures reliability of energy supply. In this paper, the mathematical model of the electricity-gas interconnected integrated energy system and its state estimation method are studied. First, considering the nonlinearity between measurement equations and state variables, a performance simulation model is proposed. Then, the state consistency equations and constraints of the coupling nodes for multiple energy sub-systems are established, and constraints are relaxed into the objective function to decouple the integrated energy system. Finally, a distributed state estimation framework is formed by combining the synchronous alternating direction multiplier method to achieve an efficient estimation of the state of the integrated energy system. A simulation model of an electricity-gas interconnected integrated energy system verifies the efficiency and accuracy of the state estimation method proposed in this paper. The results show that the average relative errors of voltage amplitude and node pressure estimated by the proposed distributed state estimation method are only 0.0132% and 0.0864%, much lower than the estimation error by using the Lagrangian relaxation method. Besides, compared with the centralized estimation method, the proposed distributed method saves 5.42 s of computation time. The proposed method is more accurate and efficient in energy allocation and utilization.

关键词: integrated energy system     state estimation     electricity-gas coupling energy system     nonlinear coupling     distributed solution    

Impact of anthropogenic heat emissions on meteorological parameters and air quality in Beijing using

《环境科学与工程前沿(英文)》 2022年 第16卷 第4期 doi: 10.1007/s11783-021-1478-3

摘要:

The Large scale Urban Consumption of energ Y model was updated and coupled with WRF.

关键词: Anthropogenic heat emissions     LUCY     High-resolution     Meteorological parameters     Air quality    

Bayes estimation of residual life by fusing multisource information

Qian ZHAO, Xiang JIA, Zhi-jun CHENG, Bo GUO

《工程管理前沿(英文)》 2018年 第5卷 第4期   页码 524-532 doi: 10.15302/J-FEM-2018034

摘要:

Residual life estimation is essential for reliability engineering. Traditional methods may experience difficulties in estimating the residual life of products with high reliability, long life, and small sample. The Bayes model provides a feasible solution and can be a useful tool for fusing multisource information. In this study, a Bayes model is proposed to estimate the residual life of products by fusing expert knowledge, degradation data, and lifetime data. The linear Wiener process is used to model degradation data, whereas lifetime data are described via the inverse Gaussian distribution. Therefore, the joint maximum likelihood (ML) function can be obtained by combining lifetime and degradation data. Expert knowledge is used according to the maximum entropy method to determine the prior distributions of parameters, thereby making this work different from existing studies that use non-informative prior. The discussion and analysis of different types of expert knowledge also distinguish our research from others. Expert knowledge can be classified into three categories according to practical engineering. Methods for determining prior distribution by using the aforementioned three types of data are presented. The Markov chain Monte Carlo is applied to obtain samples of the parameters and to estimate the residual life of products due to the complexity of the joint ML function and the posterior distribution of parameters. Finally, a numerical example is presented. The effectiveness and practicability of the proposed method are validated by comparing it with residual life estimation that uses non-informative prior. Then, its accuracy and correctness are proven via simulation experiments.

关键词: residual life estimation     Bayes model     linear Wiener process    

Thermal degradation kinetics and lifetime estimation for polycarbonate/polymethylphenylsilsesquioxane

Jiangbo WANG, Zhong XIN

《化学科学与工程前沿(英文)》 2009年 第3卷 第2期   页码 167-171 doi: 10.1007/s11705-009-0006-y

摘要: The thermal degradation behaviors of polycarbonate/polymethylphenylsilsesquioxane (FRPC) composites were investigated by thermogravimetric analysis (TGA) under isothermal conditions in nitrogen atmosphere. The isothermal kinetics equation was used to describe the thermal degradation process. The results showed that activation energy ( ), in the case of isothermal degradation, was a quick increasing function of conversion (α) for polycarbonate (PC) but was a strong and decreasing function of conversion for FRPC. Under the isothermal condition, the addition of polymethylphenylsilsesquioxane (PMPSQ) retardanted the thermal degradation and enhanced the thermal stability of PC during the early and middle stages of thermal degradation. It also indicated a possible existence of a difference in nucleation, nuclei growth, and gas diffusion mechanism in the thermal degradation process between PC and FRPC. Meanwhile, the addition of PMPSQ influenced the lifetime of PC, but the composite still met the demand in manufacturing and application.

关键词: polycarbonate     polymethylphenylsilsesquioxane     thermal degradation kinetics     activation energy     lifetime    

Effect of thermodynamic parameters on the performance of refrigerator-ejector

Lihong CAO, Yicai LIU, Chao WAN, Tianlong XIN, Qian HUANG, Mingyan ZHANG

《能源前沿(英文)》 2010年 第4卷 第4期   页码 517-521 doi: 10.1007/s11708-010-0004-2

摘要: A 3D calculation model of a refrigerator-ejector was built and simulated in a compression/injection hybrid refrigeration cycle system by using the FLUENT software of CFD. The effect of thermodynamic parameters (the pressure of primary fluid and secondary fluid) on the performance of the refrigerator-ejector was studied. The boundary conditions were set according to the actual operating condition and the parameters of refrigerator experimental sample. The numerical calculation results show that there is one optimal pressure of primary fluid, i.e., = 0.06612 MPa, corresponding to the maximum entrainment ratio, i.e., = 0.568; and there is one optimal pressure of secondary fluid, i.e., = 0.04837 MPa, corresponding to the maximum entrainment ratio, i.e., = 0.564.

关键词: refrigerator-ejector     FLUENT     thermodynamic parameters     entrainment ratio performance    

Hierarchical parameter estimation of DFIG and drive train system in a wind turbine generator

Xueping PAN, Ping JU, Feng WU, Yuqing JIN

《机械工程前沿(英文)》 2017年 第12卷 第3期   页码 367-376 doi: 10.1007/s11465-017-0429-y

摘要:

A new hierarchical parameter estimation method for doubly fed induction generator (DFIG) and drive train system in a wind turbine generator (WTG) is proposed in this paper. Firstly, the parameters of the DFIG and the drive train are estimated locally under different types of disturbances. Secondly, a coordination estimation method is further applied to identify the parameters of the DFIG and the drive train simultaneously with the purpose of attaining the global optimal estimation results. The main benefit of the proposed scheme is the improved estimation accuracy. Estimation results confirm the applicability of the proposed estimation technique.

关键词: wind turbine generator     DFIG     drive train system     hierarchical parameter estimation method     trajectory sensitivity technique    

Effects of critical geometric parameters on the optical performance of a conical cavity receiver

Hu XIAO, Yanping ZHANG, Cong YOU, Chongzhe ZOU, Quentin FALCOZ

《能源前沿(英文)》 2019年 第13卷 第4期   页码 673-683 doi: 10.1007/s11708-019-0630-2

摘要: The optical performance of a receiver has a great influence on the efficiency and stability of a solar thermal power system. Most of the literature focuses on the optical performance of receivers with different geometric shapes, but less research is conducted on the effects of critical geometric parameters. In this paper, the commercial software TracePro was used to investigate the effects of some factors on a conical cavity receiver, such as the conical angle, the number of loops of the helical tube, and the distance between the focal point of the collector and the aperture. These factors affect the optical efficiency, the maximum heat flux density, and the light distribution in the conical cavity. The optical performance of the conical receiver was studied and analyzed using the Monte Carlo ray tracing method. To make a reliable simulation, the helical tube was attached to the inner wall of the cavity in the proposed model. The results showed that the amount of light rays reaching the helical tube increases with the increasing of the conical angle, while the optical efficiency decreases and the maximum heat flux density increases. The increase in the number of loops contributed to an increase in the optical efficiency and a uniform light distribution. The conical cavity receiver had an optimal optical performance when the focal point of the collector was near the aperture.

关键词: parabolic collector     conical cavity receiver     critical geometric parameters     optical performance    

Effect of preparation parameters on catalytic properties of Pt/graphite

LIU Zhengqian, MA Jun, ZHAO Lei

《环境科学与工程前沿(英文)》 2007年 第1卷 第4期   页码 482-487 doi: 10.1007/s11783-007-0077-2

摘要: Catalytic ozonation of aqueous solutions of oxalic acid was examined in the presence of graphite-supported platinum catalysts. The catalytic activity of graphite was significantly enhanced by loading platinum. The removal efficiency of oxalic acid was 3.0%, 47.6% and 99.3% for ozonation alone, graphite catalytic ozonation and Pt/graphite catalytic ozonation in 30 min under the experimental condition, respectively. The influence of support pretreatment, solvent, impregnation time, platinum loading amount and reduction temperature on the activity of Pt/graphite catalyst was investigated. The pretreatment of graphite support had no effect on activity improvement of Pt/graphite catalyst. Solvent and impregnation time also had no great effect on the activity. Platinum loading amount and reduction temperature influenced the catalyst activity significantly. The optimal catalytic performance of Pt/graphite was obtained when 1.0% platinum loading and 623 K of reduction temperature was adopted. The Pt/graphite catalyst was used for five times with no significant decrease in its activity and more than 90% oxalic acid removal was obtained.

An energy consumption prediction approach of die casting machines driven by product parameters

《机械工程前沿(英文)》 2021年 第16卷 第4期   页码 868-886 doi: 10.1007/s11465-021-0656-0

摘要: Die casting machines, which are the core equipment of the machinery manufacturing industry, consume great amounts of energy. The energy consumption prediction of die casting machines can support energy consumption quota, process parameter energy-saving optimization, energy-saving design, and energy efficiency evaluation; thus, it is of great significance for Industry 4.0 and green manufacturing. Nevertheless, due to the uncertainty and complexity of the energy consumption in die casting machines, there is still a lack of an approach for energy consumption prediction that can provide support for process parameter optimization and product design taking energy efficiency into consideration. To fill this gap, this paper proposes an energy consumption prediction approach for die casting machines driven by product parameters. Firstly, the system boundary of energy consumption prediction is defined, and subsequently, based on the energy consumption characteristics analysis, a theoretical energy consumption model is established. Consequently, a systematic energy consumption prediction approach for die casting machines, involving product, die, equipment, and process parameters, is proposed. Finally, the feasibility and reliability of the proposed energy consumption prediction approach are verified with the help of three die casting machines and six types of products. The results show that the prediction accuracy of production time and energy consumption reached 91.64% and 85.55%, respectively. Overall, the proposed approach can be used for the energy consumption prediction of different die casting machines with different products.

关键词: die casting machine     energy consumption prediction     product parameters    

The influence of manufacturing parameters and adding support layer on the properties of Zirfon

Li XU,Yue YU,Wei LI,Yan YOU,Wei XU,Shaoxing ZHANG

《化学科学与工程前沿(英文)》 2014年 第8卷 第3期   页码 295-305 doi: 10.1007/s11705-014-1433-y

摘要: The composite separator comprising of polysulfone and zirconia was prepared by phase inversion precipitation technique. The influence of manufacturing parameters on its properties was investigated, and the results show that the manufacturing parameters affect the ionic resistance and maximum pore size significantly. A modified composite separator with a support layer was prepared to enhance the tensile strength of separator. By adding support layer, the tensile strength of the separator increases from 1.85 MPa to 13.66 MPa. In order to evaluate the practical applicability of the composite separator, a small-scale industrial electrolytic experiment was conducted to investigate the changes of cell voltage, gas purity and separator stability. The results show that the modified composite separator has a smaller cell voltage and a higher H purity than the asbestos separator, and are promising material for industrial hydrogen production.

关键词: separator     alkaline water electrolysis     manufacturing parameters     support layer    

标题 作者 时间 类型 操作

Estimation of relations among hysteretic response measures and design parameters for RC rectangular shear

A. ARAB, Ma. R. BANAN, Mo. R. BANAN, S. FARHADI

期刊论文

Dynamic characteristics and improved MPPT control of PV generator

Houda BRAHMI, Rachid DHIFAOUI

期刊论文

基于机器学习算法的模型参数区域化方法在无测站流域径流模拟中的应用

吴厚发, 张建云, 鲍振鑫, 王国庆, 王文圣, 杨艳青, 王婕

期刊论文

Intelligent algorithm for optimal meter placement and bus voltage estimation in ring main distribution

L. RAMESH, N. CHAKRABORTY, S. P. CHOWDHURY

期刊论文

Inverse identification of the mechanical parameters of a pipeline hoop and analysis of the effect of

Ye GAO, Wei SUN

期刊论文

An operating state estimation model for integrated energy systems based on distributed solution

Dengji ZHOU, Shixi MA, Dawen HUANG, Huisheng ZHANG, Shilie WENG

期刊论文

Impact of anthropogenic heat emissions on meteorological parameters and air quality in Beijing using

期刊论文

Bayes estimation of residual life by fusing multisource information

Qian ZHAO, Xiang JIA, Zhi-jun CHENG, Bo GUO

期刊论文

Thermal degradation kinetics and lifetime estimation for polycarbonate/polymethylphenylsilsesquioxane

Jiangbo WANG, Zhong XIN

期刊论文

Effect of thermodynamic parameters on the performance of refrigerator-ejector

Lihong CAO, Yicai LIU, Chao WAN, Tianlong XIN, Qian HUANG, Mingyan ZHANG

期刊论文

Hierarchical parameter estimation of DFIG and drive train system in a wind turbine generator

Xueping PAN, Ping JU, Feng WU, Yuqing JIN

期刊论文

Effects of critical geometric parameters on the optical performance of a conical cavity receiver

Hu XIAO, Yanping ZHANG, Cong YOU, Chongzhe ZOU, Quentin FALCOZ

期刊论文

Effect of preparation parameters on catalytic properties of Pt/graphite

LIU Zhengqian, MA Jun, ZHAO Lei

期刊论文

An energy consumption prediction approach of die casting machines driven by product parameters

期刊论文

The influence of manufacturing parameters and adding support layer on the properties of Zirfon

Li XU,Yue YU,Wei LI,Yan YOU,Wei XU,Shaoxing ZHANG

期刊论文