资源类型

期刊论文 80

年份

2023 7

2022 9

2021 8

2020 8

2019 5

2018 4

2017 7

2016 3

2015 4

2013 2

2012 3

2011 2

2010 3

2009 3

2008 2

2007 1

2006 2

2005 1

2003 2

2000 1

展开 ︾

关键词

Bent函数 1

GPS轨迹 1

NaOH分解 1

Spark 1

Walsh谱 1

Walsh谱分解式 1

三角形自分解 1

不确定性评估 1

严格雪崩准则 1

乘客热点预测 1

交互式图像分割；多元自适应回归样条；集成学习；薄板样条回归；半监督学习；支持向量回归 1

光度立体法；三维重构；透视投影；图像分解 1

共振隧穿器件（RTD）；非相交分解算法；通用逻辑门；真值矩阵；函数综合算法 1

分离氚 1

动力学 1

半监督；主动学习；集成学习；混合判别分析；故障分类 1

半限定方法 1

双向门控循环单元（BiGRU） 1

可逆分解电压 1

展开 ︾

检索范围：

排序： 展示方式：

Variation characteristics of atmospheric methane and carbon dioxide in summertime at a coastal site in the South China Sea

《环境科学与工程前沿（英文）》 2022年 第16卷 第11期 doi: 10.1007/s11783-022-1574-z

摘要：

● Diurnal patterns of CH4 and CO2 are clearly extracted using EEMD.

关键词： Methane     Carbon dioxide     Diurnal pattern     Ensemble empirical mode decomposition     South China Sea     Sea breeze    

HTML PDF 收藏

Robust ensemble of metamodels based on the hybrid error measure

《机械工程前沿（英文）》 2021年 第16卷 第3期   页码 623-634 doi: 10.1007/s11465-021-0641-7

摘要： Metamodels have been widely used as an alternative for expensive physical experiments or complex, time-consuming computational simulations to provide a fast but accurate analysis. However, challenge remains in the prior determination of the most suitable metamodel for a particular case because of the lack of information about the actual behavior of a system. In addition, existing studies on metamodels have largely restricted on solving deterministic problems (e.g., data from finite element models), whereas some real-life engineering problems (e.g., data from physical experiment) are stochastic problems with noisy data. In this work, a robust ensemble of metamodels (EMs) is proposed by combining three regression stand-alone metamodels in a weighted sum form. The weight factor is adaptively determined according to the hybrid error metric, which combines global and local error measures to improve the accuracy of the EMs. Furthermore, three typical individual metamodels that can filter noise are selected to construct the EMs to extend their application in practical engineering problems. Three well-known benchmark problems with different levels of noise and three engineering problems are used to verify the effectiveness of the proposed EMs. Results show that the proposed EMs have higher accuracy and robustness than the individual metamodels and other typical EMs in major cases.

关键词： metamodel     ensemble of metamodels     hybrid error measure     stochastic problem    

HTML PDF 收藏

Trend detection and stochastic simulation prediction of streamflow at Yingluoxia hydrological station, Heihe River Basin, China

Chenglong ZHANG,Mo LI,Ping GUO

《农业科学与工程前沿（英文）》 2017年 第4卷 第1期   页码 81-96 doi: 10.15302/J-FASE-2016112

摘要： Investigating long-term variation and prediction of streamflow are critical to regional water resource management and planning. Under the continuous influence of climate change and human activity, the trends of hydrologic time series are nonstationary, and consequently the established methods for hydrological frequency analysis are no longer applicable. Five methods, including the linear regression, nonlinear regression, change point analysis, wavelet analysis and Hilbert-Huang transformation, were first selected to detect and identify the deterministic and stochastic components of streamflow. The results indicated there was a significant long-term increasing trend. To test the applicability of these five methods, a comprehensive weighted index was then used to assess their performance. This index showed that the linear regression was the best method. Secondly, using the normality test for stochastic components separated by the linear regression method, a normal distribution requirement was satisfied. Next, the Monte Carlo stochastic simulation technique was used to simulate these stochastic components with normal distribution, and thus a new ensemble hydrological time series was obtained by combining the corresponding deterministic components. Finally, according to these outcomes, the streamflow at different frequencies in 2020 was predicted.

关键词： Monte Carlo     nonstationary     trend detection     streamflow prediction     decomposition and ensemble     Yingluoxia    

HTML PDF 收藏

一种基于多因素分析和多模型集成的海洋溶解氧浓度时间序列预测混合神经网络模型 Article

刘辉, 杨睿, 段铸, 吴海平

《工程（英文）》 2021年 第7卷 第12期   页码 1751-1765 doi: 10.1016/j.eng.2020.10.023

摘要：

溶解氧是水产养殖的重要指标，准确预测溶解氧浓度可有效提高水产品质量。本文提出了一种新的溶解氧混合预测模型，该模型包括多因素分析、自适应分解和优化集成三个阶段。首先，考虑到影响溶解氧浓度的因素复杂繁多，采用灰色关联度法筛选出与溶解氧关系最密切的环境因素，多因素的考虑使得模型融合更加有效。其次，运用经验小波变换方法自适应地将溶解氧、水温、盐度和氧饱和度等序列分解为子序列。然后，利用5个基准模型对经验小波变换分解出的子序列进行预测，这五个子预测模型的集成权重通过粒子群优化和引力搜索算法计算得出。最后，通过加权分配得到溶解氧多因素集成模型。来自太平洋岛屿海洋观测系统希洛WQB04站收集的时间序列数据验证了该模型的性能。实验的评价指标包括Nash-Sutcliffe效率系数、Kling-Gupta效率系数、平均绝对百分比误差、误差标准差和决定系数。实例分析表明：①所提出的模型能够获得优异的溶解氧预测结果；②该模型优于文中其他对比模型；③预测模型可用于分析溶解氧变化趋势，便于管理者能够做出更好的决策。

关键词： 溶解氧浓度预测     时间序列多步预测     多因素分析     经验小波变化分解     多模型优化集成    

HTML PDF 收藏

Processing parameter optimization of fiber laser beam welding using an ensemble of metamodels and MOABC

《机械工程前沿（英文）》 2022年 第17卷 第4期 doi: 10.1007/s11465-022-0703-5

摘要： In fiber laser beam welding (LBW), the selection of optimal processing parameters is challenging and plays a key role in improving the bead geometry and welding quality. This study proposes a multi-objective optimization framework by combining an ensemble of metamodels (EMs) with the multi-objective artificial bee colony algorithm (MOABC) to identify the optimal welding parameters. An inverse proportional weighting method that considers the leave-one-out prediction error is presented to construct EM, which incorporates the competitive strengths of three metamodels. EM constructs the correlation between processing parameters (laser power, welding speed, and distance defocus) and bead geometries (bead width, depth of penetration, neck width, and neck depth) with average errors of 10.95%, 7.04%, 7.63%, and 8.62%, respectively. On the basis of EM, MOABC is employed to approximate the Pareto front, and verification experiments show that the relative errors are less than 14.67%. Furthermore, the main effect and the interaction effect of processing parameters on bead geometries are studied. Results demonstrate that the proposed EM-MOABC is effective in guiding actual fiber LBW applications.

关键词： laser beam welding     parameter optimization     metamodel     multi-objective    

HTML PDF 收藏

Decomposition analysis applied to energy and emissions: A literature review

《工程管理前沿（英文）》   页码 625-639 doi: 10.1007/s42524-023-0270-4

摘要： Decomposition analysis has been widely used to assess the determinants of energy and CO2 emissions in academic research and policy studies. Both the methodology and application of decomposition analysis have been largely improved in the past decades. After more than 50 years’ developments, decomposition studies have become increasingly sophisticated and diversified, and tend to converge internally and integrate with other analytical approaches externally. A good understanding of the literature and state of the art is critical to identify knowledge gaps and formulate future research agenda. To this end, this study presents a literature survey for decomposition analysis applied to energy and emission issues, with a focus on the period of 2016–2021. A review for three individual decomposition techniques is first conducted, followed by a synthesis of emerging trends and features for the decomposition analysis literature as a whole. The findings are expected to direct future research in decomposition analysis.

关键词： index decomposition analysis     structural decomposition analysis     production decomposition analysis     energy     CO2 emissions    

HTML PDF 收藏

Efficient Identification of water conveyance tunnels siltation based on ensemble deep learning

Xinbin WU; Junjie LI; Linlin WANG

《结构与土木工程前沿（英文）》 2022年 第16卷 第5期   页码 564-575 doi: 10.1007/s11709-022-0829-x

摘要： The inspection of water conveyance tunnels plays an important role in water diversion projects. Siltation is an essential factor threatening the safety of water conveyance tunnels. Accurate and efficient identification of such siltation can reduce risks and enhance safety and reliability of these projects. The remotely operated vehicle (ROV) can detect such siltation. However, it needs to improve its intelligent recognition of image data it obtains. This paper introduces the idea of ensemble deep learning. Based on the VGG16 network, a compact convolutional neural network (CNN) is designed as a primary learner, called Silt-net, which is used to identify the siltation images. At the same time, the fully-connected network is applied as the meta-learner, and stacking ensemble learning is combined with the outputs of the primary classifiers to obtain satisfactory classification results. Finally, several evaluation metrics are used to measure the performance of the proposed method. The experimental results on the siltation dataset show that the classification accuracy of the proposed method reaches 97.2%, which is far better than the accuracy of other classifiers. Furthermore, the proposed method can weigh the accuracy and model complexity on a platform with limited computing resources.

关键词： water conveyance tunnels     siltation images     remotely operated vehicles     deep learning     ensemble learning     computer vision    

HTML PDF 收藏

Catalytic decomposition of low level ozone with gold nanoparticles supported on activated carbon

Pengyi ZHANG , Bo ZHANG , Rui SHI ,

《环境科学与工程前沿（英文）》 2009年 第3卷 第3期   页码 281-288 doi: 10.1007/s11783-009-0032-5

摘要： Highly dispersed gold nanoparticles were supported on coal-based activated carbon (AC) by a sol immobilization method and were used to investigate their catalytic activity for low-level ozone decomposition at ambient temperature. Nitrogen adsorption-desorption, scanning electron microscope (SEM), and X-ray photoelectron spectroscopy (XPS) were used to characterize the catalysts before and after ozone decomposition. The results showed that the supported gold nanoparticles prepared with microwave heating were much smaller and more uniformly dispersed on the activated carbon than those prepared with traditional conduction heating, exhibiting higher catalytic activity for ozone decomposition. The pH values of gold precursor solution significantly influenced the catalytic activity of supported gold for ozone decomposition, and the best pH value was 8. In the case of space velocity of 120000h, inlet ozone concentration of 50mg/m, and relative humidity of 45%, the Au/AC catalyst maintained the ozone removal ratio at 90.7% after 2500min. After being used for ozone decomposition, the surface carbon of the catalyst was partly oxidized and the oxygen content increased accordingly, while its specific surface area and pore volume only decreased a little. Ozone was mainly catalytically decomposed by the gold nanoparticles supported on the activated carbon.

关键词： ozone decomposition     activated carbon     gold nanoparticles     catalysis     sodium citrate     microwave    

HTML PDF 收藏

A novel ensemble model for predicting the performance of a novel vertical slot fishway

Aydin SHISHEGARAN, Mohammad SHOKROLLAHI, Ali MIRNOROLLAHI, Arshia SHISHEGARAN, Mohammadreza MOHAMMAD KHANI

《结构与土木工程前沿（英文）》 2020年 第14卷 第6期   页码 1418-1444 doi: 10.1007/s11709-020-0664-x

摘要： We investigate the performance of a novel vertical slot fishway by employing finite volume and surrogate models. Multiple linear regression, multiple log equation regression, gene expression programming, and combinations of these models are employed to predict the maximum turbulence, maximum velocity, resting area, and water depth of the middle pool in the fishway. The statistical parameters and error terms, including the coefficient of determination, root mean square error, normalized square error, maximum positive and negative errors, and mean absolute percentage error were employed to evaluate and compare the accuracy of the models. We also conducted a parametric study. The independent variables include the opening between baffles ( ), the ratio of the length of the large and small baffles, the volume flow rate, and the angle of the large baffle. The results show that the key parameters of the maximum turbulence and velocity are the volume flow rate and .

关键词： novel vertical slot fishway     parametric study     finite volume method     ensemble model     gene expression programming    

HTML PDF 收藏

Product decomposition strategy for optimization of supply chain planning

Braulio BRUNAUD, Maria Paz OCHOA, Ignacio E. GROSSMANN

《工程管理前沿（英文）》 2018年 第5卷 第4期   页码 466-478 doi: 10.15302/J-FEM-2018059

摘要：

Optimization of large-scale supply chain planning models requires the application of decomposition strategies to reduce the computational expense. Two major options are to use either spatial or temporal Lagrangean decomposition. In this paper, to further reduce the computational expense a novel decomposition scheme by products is presented. The decomposition is based on a reformulation of knapsack constraints in the problem. The new approach allows for simultaneous decomposition by products and by time periods, enabling the generation of a large number of subproblems, that can be solved by using parallel computing. The case study shows that the proposed product decomposition exhibits similar performance as the temporal decomposition, and that selecting different orders of products and aggregating the linking constraints can improve the efficiency of the algorithm.

关键词： supply chain planning     Lagrangean decomposition     mixed-integer programming    

HTML PDF 收藏

Variational mode decomposition based modal parameter identification in civil engineering

Mingjie ZHANG, Fuyou XU

《结构与土木工程前沿（英文）》 2019年 第13卷 第5期   页码 1082-1094 doi: 10.1007/s11709-019-0537-3

摘要： An out-put only modal parameter identification method based on variational mode decomposition (VMD) is developed for civil structure identifications. The recently developed VMD technique is utilized to decompose the free decay response (FDR) of a structure into to modal responses. A novel procedure is developed to calculate the instantaneous modal frequencies and instantaneous modal damping ratios. The proposed identification method can straightforwardly extract the mode shape vectors using the modal responses extracted from the FDRs at all available sensors on the structure. A series of numerical and experimental case studies are conducted to demonstrate the efficiency and highlight the superiority of the proposed method in modal parameter identification using both free vibration and ambient vibration data. The results of the present method are compared with those of the empirical mode decomposition-based method, and the superiorities of the present method are verified. The proposed method is proved to be efficient and accurate in modal parameter identification for both linear and nonlinear civil structures, including structures with closely spaced modes, sudden modal parameter variation, and amplitude-dependent modal parameters, etc.

关键词： modal parameter identification     variational mode decomposition     civil structure     nonlinear system     closely spaced modes    

HTML PDF 收藏

Mechanism of methanol decomposition on the Pd/WC(0001) surface unveiled by first-principles calculations

Jinhua Zhang, Yuanbin She

《化学科学与工程前沿（英文）》 2020年 第14卷 第6期   页码 1052-1064 doi: 10.1007/s11705-019-1908-y

摘要： In this study, the decomposition of methanol into the CO and H species on the Pd/tungsten carbide (WC)(0001) surface is systematically investigated using periodic density functional theory (DFT) calculations. The possible reaction pathways and intermediates are determined. The results reveal that saturated molecules, i.e., methanol and formaldehyde, adsorb weakly on the Pd/WC(0001) surface. Both CO and H prefer three-fold sites, with adsorption energies of ‒1.51 and ‒2.67 eV, respectively. On the other hand, CH O stably binds at three-fold and bridge sites, with an adsorption energy of ‒2.58 eV. However, most of the other intermediates tend to adsorb to the surface with the carbon and oxygen atoms in their sp and hydroxyl-like configurations, respectively. Hence, the C atom of CH OH preferentially attaches to the top sites, CHOH and CH O adsorb at the bridge sites, while COH and CHO occupy the three-fold sites. The DFT calculations indicate that the rupture of the initial C–H bond promotes the decomposition of CH OH and CH OH, whereas in the case of CHOH, O–H bond scission is favored over the C–H bond rupture. Thus, the most probable methanol decomposition pathway on the Pd/WC(0001) surface is CH OH → CH OH → -CHOH → CHO → CO. The present study demonstrates that the synergistic effect of WC (as carrier) and Pd (as catalyst) alters the CH OH decomposition pathway and reduces the noble metal utilization.

关键词： density functional theory     methanol     direct methanol fuel cells     WC(0001)-supported Pd monolayer     decomposition mechanism    

HTML PDF 收藏

Ensemble unit and AI techniques for prediction of rock strain

Pradeep T; Pijush SAMUI; Navid KARDANI; Panagiotis G ASTERIS

《结构与土木工程前沿（英文）》 2022年 第16卷 第7期   页码 858-870 doi: 10.1007/s11709-022-0831-3

摘要： The behavior of rock masses is influenced by a variety of forces, with measurement of stress and strain playing the most critical roles in assessing deformation. The laboratory test for determining strain at each location within rock samples is expensive and difficult but rock strain data are important for predicting failure of rock material. Many researchers employ AI technology in order to solve these difficulties. AI algorithms such as gradient boosting machine (GBM), support vector regression (SVR), random forest (RF), and group method of data handling (GMDH) are used to efficiently estimate the strain at every point within a rock sample. Additionally, the ensemble unit (EnU) may be utilized to evaluate rock strain. In this study, 3000 experimental data are used for the purpose of prediction. The obtained strain values are then evaluated using various statistical parameters and compared to each other using EnU. Ranking analysis, stress-strain curve, Young’s modulus, Poisson’s ratio, actual vs. predicted curve, error matrix and the Akaike’s information criterion (AIC) values are used for comparing models. The GBM model achieved 98.16% and 99.98% prediction accuracy (in terms of values of R2) in the longitudinal and lateral dimensions, respectively, during the testing phase. The GBM model, based on the experimental data, has the potential to be a new option for engineers to use when assessing rock strain.

关键词： prediction     strain     ensemble unit     rank analysis     error matrix    

HTML PDF 收藏

Dielectric barrier micro-plasma reactor with segmented outer electrode for decomposition of pure CO

Baowei Wang, Xiaoxi Wang, Bo Zhang

《化学科学与工程前沿（英文）》 2021年 第15卷 第3期   页码 687-697 doi: 10.1007/s11705-020-1974-1

摘要： Four coaxial cylinder dielectric barrier discharge micro-plasma reactors were designed for the non-catalytic decomposition of pure CO into CO and O at low temperature and ambient pressure. The influence of segmented outer electrodes on the electrical characteristics and the reaction performance was investigated. Experimental results indicated that the introduction of segmented outer electrodes can significantly promote the decomposition of CO . Encouragingly, the highest conversion of 13.1% was obtained at an applied voltage of 18 kV, which was a substantial increase of 39.4% compared to the traditional device. Compared with other types of dielectric barrier discharge plasma reactors, the proposed segmented outer electrode micro-plasma reactor can give a higher CO conversion and acceptable energy efficiency. The increase in conversion can be attributed mainly to the enhanced corona discharge caused by the fringe effect at electrode edges, the increase in energy density and the increase in the number of micro-discharges. In addition, detailed electrical characterization was performed to reveal some trends in the electrical behavior of proposed reactors.

关键词： CO2 decomposition     dielectric barrier discharge     segmented outer electrodes     electrical analysis     reactor design    

HTML PDF 收藏

Thermal decomposition mechanism of ammonium sulfate catalyzed by ferric oxide

Xingfu SONG, Jingcai ZHAO, Yunzhao LI, Ze SUN, Jianguo YU

《化学科学与工程前沿（英文）》 2013年 第7卷 第2期   页码 210-217 doi: 10.1007/s11705-013-1320-y

摘要： The decomposition mechanism of ammonium sulfate catalyzed by ferric oxide was investigated in this paper. The decomposition kinetics parameters were determined via a global optimization of the Kissinger iterative method using the non-isothermal thermogravimetric analysis data. The products and intermediates were synchronously characterized by X-ray diffraction and mass spectrometry. The obtained results indicate that the decomposition process of ammonium sulfate catalyzed by ferric oxide can be divided into four stages of which the activation energies are 123.64, 126.58, 178.77 and 216.99 kJ·mol respectively. The decomposition mechanisms at the first and the fourth stage both belong to Mample power theorem, the second stage belongs to Avrami-Erofeev equation and the third belongs to contracting sphere (volume) equation. The corresponding pre-exponential factors ( ) are calculated simultaneously.

关键词： ammonium sulfate     decomposition kinetics     ferric oxide     thermogravimetric analysis    

HTML PDF 收藏

标题 作者 时间 类型 操作

Variation characteristics of atmospheric methane and carbon dioxide in summertime at a coastal site in the South China Sea

期刊论文

Robust ensemble of metamodels based on the hybrid error measure

期刊论文

Trend detection and stochastic simulation prediction of streamflow at Yingluoxia hydrological station, Heihe River Basin, China

Chenglong ZHANG,Mo LI,Ping GUO

期刊论文

一种基于多因素分析和多模型集成的海洋溶解氧浓度时间序列预测混合神经网络模型

刘辉, 杨睿, 段铸, 吴海平

期刊论文

Processing parameter optimization of fiber laser beam welding using an ensemble of metamodels and MOABC

期刊论文

Decomposition analysis applied to energy and emissions: A literature review

期刊论文

Efficient Identification of water conveyance tunnels siltation based on ensemble deep learning

Xinbin WU; Junjie LI; Linlin WANG

期刊论文

Catalytic decomposition of low level ozone with gold nanoparticles supported on activated carbon

Pengyi ZHANG , Bo ZHANG , Rui SHI ,

期刊论文

A novel ensemble model for predicting the performance of a novel vertical slot fishway

Aydin SHISHEGARAN, Mohammad SHOKROLLAHI, Ali MIRNOROLLAHI, Arshia SHISHEGARAN, Mohammadreza MOHAMMAD KHANI

期刊论文

Product decomposition strategy for optimization of supply chain planning

Braulio BRUNAUD, Maria Paz OCHOA, Ignacio E. GROSSMANN

期刊论文

Variational mode decomposition based modal parameter identification in civil engineering

Mingjie ZHANG, Fuyou XU

期刊论文

Mechanism of methanol decomposition on the Pd/WC(0001) surface unveiled by first-principles calculations

Jinhua Zhang, Yuanbin She

期刊论文

Ensemble unit and AI techniques for prediction of rock strain

Pradeep T; Pijush SAMUI; Navid KARDANI; Panagiotis G ASTERIS

期刊论文

Dielectric barrier micro-plasma reactor with segmented outer electrode for decomposition of pure CO

Baowei Wang, Xiaoxi Wang, Bo Zhang

期刊论文

Thermal decomposition mechanism of ammonium sulfate catalyzed by ferric oxide

Xingfu SONG, Jingcai ZHAO, Yunzhao LI, Ze SUN, Jianguo YU

期刊论文