资源类型

期刊论文 1522

会议视频 28

会议信息 2

年份

2024 1

2023 65

2022 116

2021 107

2020 77

2019 104

2018 86

2017 86

2016 65

2015 86

2014 81

2013 62

2012 78

2011 71

2010 72

2009 49

2008 73

2007 86

2006 36

2005 26

展开 ︾

关键词

风险分析 9

能源 7

分析 4

可持续发展 4

对策 4

影响因素 4

数值模拟 4

隧道 4

ANSYS 3

农业科学 3

抗击疫情 3

数值分析 3

环境 3

营养健康 3

裂缝 3

2035年 2

BNLAS 2

COVID-19 2

DX桩 2

展开 ︾

检索范围:

排序: 展示方式:

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    

Analysis of nonlinear channel friction inverse problem

CHENG Weiping, LIU Guohua

《结构与土木工程前沿(英文)》 2007年 第1卷 第2期   页码 205-210 doi: 10.1007/s11709-007-0024-0

摘要: Based on the Backus-Gilbert inverse theory, the singular value decomposition (SVD) for general inverse matrices and the optimization algorithm are used to solve the channel friction inverse problem. The resolution and covariance friction inverse model in matrix form is developed to examine the reliability of solutions. Theoretical analyses demonstrate that the convergence rate of the general Newton optimization algorithm is in the second-order. The Wiggins method is also incorporated into the algorithm. Using the method, noise can be suppressed effectively, and the results are close to accurate solutions with proper control parameters. Also, the numerical stability can be improved.

关键词: singular     SVD     second-order     covariance     Theoretical    

Inverse uncertainty characteristics of pollution source identification for river chemical spill incidentsby stochastic analysis

Jiping Jiang, Feng Han, Yi Zheng, Nannan Wang, Yixing Yuan

《环境科学与工程前沿(英文)》 2018年 第12卷 第5期 doi: 10.1007/s11783-018-1081-4

摘要:

Uncertainty rules of pollution source inversion are revealed by stochastic analysis

A release load is most easily inversed and source locations own largest uncertainty

Instantaneous spill assumption has much less uncertainty than continuous spill

The estimated release locations and times negatively deviate from real values

The new findings improve monitoring network design and emergency response to spills

关键词: River chemical spills     Emergency response     Pollution source inversion     Inverse uncertainty analysis     Regional Sensitivity Analysis method (RSA)     Monte Carlo analysis toolbox (MCAT)    

Inverse Gaussian process-based corrosion growth modeling and its application in the reliability analysis

Hao QIN, Shenwei ZHANG, Wenxing ZHOU

《结构与土木工程前沿(英文)》 2013年 第7卷 第3期   页码 276-287 doi: 10.1007/s11709-013-0207-9

摘要: This paper describes an inverse Gaussian process-based model to characterize the growth of metal-loss corrosion defects on energy pipelines. The model parameters are evaluated using the Bayesian methodology by combining the inspection data obtained from multiple inspections with the prior distributions. The Markov Chain Monte Carlo (MCMC) simulation techniques are employed to numerically evaluate the posterior marginal distribution of each individual parameter. The measurement errors associated with the ILI tools are considered in the Bayesian inference. The application of the growth model is illustrated using an example involving real inspection data collected from an in-service pipeline in Alberta, Canada. The results indicate that the model in general can predict the growth of corrosion defects reasonably well. Parametric analyses associated with the growth model as well as reliability assessment of the pipeline based on the growth model are also included in the example. The proposed model can be used to facilitate the development and application of reliability-based pipeline corrosion management.

关键词: pipeline     metal-loss corrosion     inverse Gaussian process     measurement error     hierarchical Bayesian     Markov Chain Monte Carlo (MCMC)    

Performance of inverse fluidized bed bioreactor in treating starch wastewater

M. RAJASIMMAN, C. KARTHIKEYAN

《化学科学与工程前沿(英文)》 2009年 第3卷 第3期   页码 235-239 doi: 10.1007/s11705-009-0020-0

摘要: Aerobic digestion of starch industry wastewater was carried out in an inverse fluidized bed bioreactor using low-density (870 kg/m ) polypropylene particles. Experiments were carried out at different initial substrate concentrations of 2250, 4475, 6730, and 8910 mg COD/L and for various hydraulic retention times (HRT) of 40, 32, 24, 16, and 8 h. Degradation of organic matter was studied at different organic loading rates (OLR) by varying the HRT and the initial substrate concentration. From the results it was observed that the maximum COD removal of 95.6% occurred at an OLR of 1.35 kg COD/(m ·d) and the minimum of 51.8% at an OLR of 26.73 kg COD/(m ·d). The properties of biomass accumulation on the surface of particles were also studied. It was observed that constant biomass loading was achieved over the entire period of operation.

关键词: inverse fluidization     low-density particles     polypropylene     starch     biofilm    

Efficient conversion of lignin to alkylphenols over highly stable inverse spinel MnFeO catalysts

《化学科学与工程前沿(英文)》 2023年 第17卷 第8期   页码 1085-1095 doi: 10.1007/s11705-022-2236-1

摘要: The aromatic properties of lignin make it a promising source of valuable chemicals and fuels. Developing efficient and stable catalysts to effectively convert lignin into high-value chemicals is challenging. In this work, MnFe2O4 spinel catalysts with oxygen-rich vacancies and porous distribution were synthesized by a simple solvothermal process and used to catalyze the depolymerization of lignin in an isopropanol solvent system. The specific surface area was 110.5 m2∙g–1, which substantially increased the active sites for lignin depolymerization compared to Fe3O4. The conversion of lignin reached 94%, and the selectivity of alkylphenols exceeded 90% after 5 h at 250 °C. Underpinned by characterizations, products, and density functional theory analysis, the results showed that the catalytic performance of MnFe2O4 was attributed to the composition of Mn and Fe with strong Mn–O–Fe synergy. In addition, the cycling experiments and characterization showed that the depolymerized lignin on MnFe2O4 has excellent cycling stability. Thus, our work provides valuable insights into the mechanism of lignin catalytic depolymerization and paves the way for the industrial-scale application of this process.

关键词: lignin depolymerization     spinel     catalysts     hydrogenation    

Research on Anthropomorphic Obstacle Avoidance Trajectory Planning for Adaptive Driving Scenarios Based on Inverse

Jian Wu,Yang Yan,Yulong Liu,Yahui Liu,

《工程(英文)》 doi: 10.1016/j.eng.2023.07.018

摘要: The forward design of trajectory planning strategies requires preset trajectory optimization functions, resulting in poor adaptability of the strategy and an inability to accurately generate obstacle avoidance trajectories that conform to real driver behavior habits. In addition, owing to the strong time-varying dynamic characteristics of obstacle avoidance scenarios, it is necessary to design numerous trajectory optimization functions and adjust the corresponding parameters. Therefore, an anthropomorphic obstacle-avoidance trajectory planning strategy for adaptive driving scenarios is proposed. First, numerous expert-demonstrated trajectories are extracted from the HighD natural driving dataset. Subsequently, a trajectory expectation feature-matching algorithm is proposed that uses maximum entropy inverse reinforcement learning theory to learn the extracted expert-demonstrated trajectories and achieve automatic acquisition of the optimization function of the expert-demonstrated trajectory. Furthermore, a mapping model is constructed by combining the key driving scenario information that affects vehicle obstacle avoidance with the weight of the optimization function, and an anthropomorphic obstacle avoidance trajectory planning strategy for adaptive driving scenarios is proposed. Finally, the proposed strategy is verified based on real driving scenarios. The results show that the strategy can adjust the weight distribution of the trajectory optimization function in real time according to the “emergency degree” of obstacle avoidance and the state of the vehicle. Moreover, this strategy can generate anthropomorphic trajectories that are similar to expert-demonstrated trajectories, effectively improving the adaptability and acceptability of trajectories in driving scenarios.

关键词: Obstacle avoidance trajectory planning     Inverse reinforcement theory     Anthropomorphic     Adaptive driving scenarios    

Inverse kinematics analysis and numerical control experiment for PRS-XY style hybrid machining tool

JIA Dongyong, ZHANG Jianmin, SUN Hongchang, NIU Zhigang

《机械工程前沿(英文)》 2007年 第2卷 第2期   页码 235-238 doi: 10.1007/s11465-007-0041-7

摘要: This paper analyzed the inverse kinematics for the new Parallel rotate slider- axes (PRS-) style hybrid machining tool and educed the five axes linkage inverse kinematics transform formula on the basis of the coordinates of the and virtual axes. The program for the PRS-XY style hybrid machining tool in accordance with the program manner for the common numerical control (NC) machine tool was made. The results of the experiments prove that the inverse kinematics transform formula is correct.

关键词: numerical     accordance     transform formula     virtual     slider-    

Inverse Kinematics Analysis of General 6R Serial Robot Mechanism Based on Groebner Base

WANG Yan, HANG Lu-bin, YANG Ting-li

《机械工程前沿(英文)》 2006年 第1卷 第1期   页码 115-124 doi: 10.1007/s11465-005-0022-7

摘要:

This study presents a solution for the inverse kinematics problem in serial 6R manipulator. Using only seven equations composed of Duffy s four kinematical equations containing three angles and three corresponding angles identical equations instead of the traditional 14 equations, the authors reduced the inverse kinematics problem in the general 6R manipulator to a univariate polynomial with a minimum degree based on the Groebner Base method. From that, they concluded that the maximum number of the solutions is 16, generally. Also, the mathematics mechanization method can be extended to solve other mechanism problems involving nonlinear equations symbolically.

关键词: identical     manipulator     univariate polynomial     mechanism     traditional    

Precise semi-analytical inverse kinematic solution for 7-DOF offset manipulator with arm angle optimization

《机械工程前沿(英文)》 2021年 第16卷 第3期   页码 435-450 doi: 10.1007/s11465-021-0630-x

摘要: Seven-degree-of-freedom redundant manipulators with link offset have many advantages, including obvious geometric significance and suitability for configu-ration control. Their configuration is similar to that of the experimental module manipulator (EMM) in the Chinese Space Station Remote Manipulator System. However, finding the analytical solution of an EMM on the basis of arm angle parameterization is difficult. This study proposes a high-precision, semi-analytical inverse method for EMMs. Firstly, the analytical inverse kinematic solution is established based on joint angle parameterization. Secondly, the analytical inverse kinematic solution for a non-offset spherical–roll–spherical (SRS) redundant manipulator is derived based on arm angle parameterization. The approximate solution of the EMM is calculated in accordance with the relationship between the joint angles of the EMM and the SRS manipulator. Thirdly, the error is corrected using a numerical method through the analytical inverse solution based on joint angle parameterization. After selecting the stride and termination condition, the precise inverse solution is computed for the EMM based on arm angle parameterization. Lastly, case solutions confirm that this method has high precision, and the arm angle parameterization method is superior to the joint angle parameterization method in terms of parameter selection.

关键词: 7-DOF redundant manipulator     inverse kinematics     semi-analytical     arm angle     link offset    

General closed-form inverse kinematics for arbitrary three-joint subproblems based on the product of

《机械工程前沿(英文)》 2022年 第17卷 第2期 doi: 10.1007/s11465-022-0681-7

摘要: The inverse kinematics problems of robots are usually decomposed into several Paden–Kahan subproblems based on the product of exponential model. However, the simple combination of subproblems cannot solve all the inverse kinematics problems, and there is no common approach to solve arbitrary three-joint subproblems in an arbitrary postural relationship. The novel algebraic geometric (NAG) methods that obtain the general closed-form inverse kinematics for all types of three-joint subproblems are presented in this paper. The geometric and algebraic constraints are used as the conditions precedent to solve the inverse kinematics of three-joint subproblems. The NAG methods can be applied in the inverse kinematics of three-joint subproblems in an arbitrary postural relationship. The inverse kinematics simulations of all three-joint subproblems are implemented, and simulation results indicating that the inverse solutions are consistent with the given joint angles validate the general closed-form inverse kinematics. Huaque III minimally invasive surgical robot is used as the experimental platform for the simulation, and a master–slave tracking experiment is conducted to verify the NAG methods. The simulation result shows the inverse solutions and six sets given joint angles are consistent. Additionally, the mean and maximum of the master–slave tracking experiment for the closed-form solution are 0.1486 and 0.4777 mm, respectively, while the mean and maximum of the master–slave tracking experiment for the compensation method are 0.3188 and 0.6394 mm, respectively. The experiments results demonstrate that the closed-form solution is superior to the compensation method. The results verify the proposed general closed-form inverse kinematics based on the NAG methods.

关键词: inverse kinematics     Paden–Kahan subproblems     three-joint subproblems     product of exponential     closed-form solution    

基于Inverse Butterlfy网络的高效可重构循环移位单元 Article

Chao MA, Zi-bin DAI, Wei LI, Hai-juan ZANG

《信息与电子工程前沿(英文)》 2017年 第18卷 第11期   页码 1784-1794 doi: 10.1631/FITEE.1601265

摘要: 本文提出了一种利用inverse butterfly网络的自路由特性完成循环移位、短字循环移位等操作的可重构控制信息生成算法。

关键词: 循环移位操作;自路由;控制信息生成算法;Inverse butterfly网络    

矿井提升机绳系合理激励加速度反演分析与设计

彭佑多,刘德顺,朱萍玉,张永忠,郭迎福

《中国工程科学》 2002年 第4卷 第4期   页码 64-68

摘要:

提升绳系的激励加速度决定着提升容器的乘坐舒适性和提升钢绳中动张力的大小,过大的动张力将导致滑绳(摩擦提升)或断绳(缠绕式提升)。基于提升钢绳为连续弹性杆的条件,建立了绳系的偏微分方程,采用特性线数值分析方法,以满足提升容器的乘坐舒适性和提升钢丝绳产生较小动张力为目标,对矿井提升机绳系要求的合理激励加速度曲线进行了反演分析与设计。

关键词: 提升钢丝绳系     激励加速度     乘坐舒适性     动张力     反演设计    

Method for solving the nonlinear inverse problem in gas face seal diagnosis based on surrogate models

《机械工程前沿(英文)》 2022年 第17卷 第3期 doi: 10.1007/s11465-022-0689-z

摘要: Physical models carry quantitative and explainable expert knowledge. However, they have not been introduced into gas face seal diagnosis tasks because of the unacceptable computational cost of inferring the input fault parameters for the observed output or solving the inverse problem of the physical model. The presented work develops a surrogate-model-assisted method for solving the nonlinear inverse problem in limited physical model evaluations. The method prepares a small initial database on sites generated with a Latin hypercube design and then performs an iterative routine that benefits from the rapidity of the surrogate models and the reliability of the physical model. The method is validated on simulated and experimental cases. Results demonstrate that the method can effectively identify the parameters that induce the abnormal signal output with limited physical model evaluations. The presented work provides a quantitative, explainable, and feasible approach for identifying the cause of gas face seal contact. It is also applicable to mechanical devices that face similar difficulties.

关键词: surrogate model     gas face seal     fault diagnosis     nonlinear dynamics     tribology    

Design and mechanism insight on SiC quantum dots sensitized inverse opal TiO with superior photocatalytic

《化学科学与工程前沿(英文)》 2023年 第17卷 第12期   页码 1913-1924 doi: 10.1007/s11705-023-2350-8

摘要: The combination of SiC quantum dots sensitized inverse opal TiO2 photocatalyst is designed in this work and then applied in wastewater purification under simulated sunlight. From various spectroscopic techniques, it is found that electrons transfer directionally from SiC quantum dots to inverse opal TiO2, and the energy difference between their conduction/valence bands can reduce the recombination rate of photogenerated carriers and provide a pathway with low interfacial resistance for charge transfer inside the composite. As a result, a typical type-II mechanism is proved to dominate the photoinduced charge transfer process. Meanwhile, the composite achieves excellent photocatalytic performances (the highest apparent kinetic constant of 0.037 min–1), which is 6.2 times (0.006 min–1) and 2.1 times (0.018 min–1) of the bare inverse opal TiO2 and commercial P25 photocatalysts. Therefore, the stability and non-toxicity of SiC quantum dots sensitized inverse opal TiO2 composite enables it with great potential in practical photocatalytic applications.

关键词: inverse opal TiO2     silicon carbide quantum dots     quantum dot sensitized photocatalyst     type-II charge transfer route    

标题 作者 时间 类型 操作

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

Ye GAO, Wei SUN

期刊论文

Analysis of nonlinear channel friction inverse problem

CHENG Weiping, LIU Guohua

期刊论文

Inverse uncertainty characteristics of pollution source identification for river chemical spill incidentsby stochastic analysis

Jiping Jiang, Feng Han, Yi Zheng, Nannan Wang, Yixing Yuan

期刊论文

Inverse Gaussian process-based corrosion growth modeling and its application in the reliability analysis

Hao QIN, Shenwei ZHANG, Wenxing ZHOU

期刊论文

Performance of inverse fluidized bed bioreactor in treating starch wastewater

M. RAJASIMMAN, C. KARTHIKEYAN

期刊论文

Efficient conversion of lignin to alkylphenols over highly stable inverse spinel MnFeO catalysts

期刊论文

Research on Anthropomorphic Obstacle Avoidance Trajectory Planning for Adaptive Driving Scenarios Based on Inverse

Jian Wu,Yang Yan,Yulong Liu,Yahui Liu,

期刊论文

Inverse kinematics analysis and numerical control experiment for PRS-XY style hybrid machining tool

JIA Dongyong, ZHANG Jianmin, SUN Hongchang, NIU Zhigang

期刊论文

Inverse Kinematics Analysis of General 6R Serial Robot Mechanism Based on Groebner Base

WANG Yan, HANG Lu-bin, YANG Ting-li

期刊论文

Precise semi-analytical inverse kinematic solution for 7-DOF offset manipulator with arm angle optimization

期刊论文

General closed-form inverse kinematics for arbitrary three-joint subproblems based on the product of

期刊论文

基于Inverse Butterlfy网络的高效可重构循环移位单元

Chao MA, Zi-bin DAI, Wei LI, Hai-juan ZANG

期刊论文

矿井提升机绳系合理激励加速度反演分析与设计

彭佑多,刘德顺,朱萍玉,张永忠,郭迎福

期刊论文

Method for solving the nonlinear inverse problem in gas face seal diagnosis based on surrogate models

期刊论文

Design and mechanism insight on SiC quantum dots sensitized inverse opal TiO with superior photocatalytic

期刊论文