检索结果-内蒙古大学图书馆

SSRN 2022年

作者： Wang, Guilian Lv, Bingrui Liu, Bin Fang, Fengzhou Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin 300384 China School of Mechanical and Materials Engineering University College Dublin Belfield D04 V1W8 Ireland Key Laboratory of Advanced Ceramics and Machining Technology Ministry of Education Tianjin University Tianjin300072 China Tianjin Laboratory of Control Theory and Applications in Complicated System School of Electrical and Electronic Engineering Tianjin University of Technology Tianjin 300384 China Tianjin University Tianjin 300072 China

Riblet surfaces find wide applications owing to their excellent performance such as drag reduction. In this study, sub-aperture tool is investigated to polish the riblet surfaces, two main different curvatures at any point of this kind of tool surface are proposed. A series of simulation studies are conducted to investigate the effect of key parameters on the material removal, such as tool radius, inclination angle, polishing pressure, and tool speed. The results show that a higher difference between the tool radius values in two directions increases the difference between the major and minor axes of the contact area. Based on experimental tests and simulation analysis, it is conluded that the profile and depth of material removal distribution both increase with an increase in polishing pressure, the material removal profile remains constant but the removal detpth increases with an increase in polishing speed, and the parameter K is a time-dependent. © 2022, The Authors. All rights reserved.

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Significant Wave Height Prediction Based on VMD-SA-MLP-BP

Significant Wave Height Prediction Based on VMD-SA-MLP-BP

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Chinese Automation Congress (CAC)

作者： Yining Wu Runfeng Zhang Fang Liu Zhenzhong Liu Jianguo Wu Haonan Dong Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of Technology Yichang Research Institute of Testing Technology Yichang China Tianjin Hanhailanfan Marine Technology Co. Ltd. Tianjin China School of Computer Science and Engineering Tianjin University of Technology Tianjin China

Waves seriously impact port construction, worldwide route planning, military activities, and wave power generation. To improve the accuracy of significant wave height prediction, we proposed a novel prediction method, a multi-layer perceptron combined with a backpropagation adjustment (MLP-BP) prediction model that combines mutation mode decomposition (VMD) and a simulated annealing optimization algorithm (SA). Firstly, we use the variable modulus method to decompose the significant wave height sequence data and transform the wave height sequence into multiple different sub-modes (IMF) to reduce the complexity and non-stationarity of the data. Secondly, the simulated annealing algorithm (SA) is used to optimize the weight and bias of the MLP-BP neural network to find the optimal parameter configuration and improve the performance and generalization ability of the prediction model. Finally, the decomposed sub-modal components of each significant wave height sequence are inserted into the MLP-BP neural network and the predicted values of each element are summed to obtain the final significant wave height prediction. The prediction results of the SSA-MLP-BP, PSO-MLP-BP, SA-MLP-BP, and VMD-SA-MLP-BP were compared and demonstrated that the VMD-SA-MLP-BP model performed best. The MAE, MAPE, MSE, RMSE, and R2 of the prediction evaluation indexes were 0.036 m, 11.7%, 0.004 m 2 , 0.067 m, and 0.983, respectively, which performed well in predicting significant wave height.

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Individual Dynamic Graduation Requirements Achievements of Students 2020

Individual Dynamic Graduation Requirements Achievements of S...

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5th International Conference on Distance Education and Learning, ICDEL 2020

作者： Zhao, Yalu Hao, Shuying Yang, Lu Xia, Guofeng Hu, Wenhua Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of Technology Tianjin China Chongqing Engineering Research Center for Advanced Intelligent Manufacturing Technology Chongqing China

ISBN: (纸本)9781450377546

In the engineering education accreditation system, it is clearly required that the major applying for certification should prove the achievement of graduation requirements with appraisal. The common appraisal methods of graduation requirements achievements (GRAs) focus on the whole situation of graduates, which lacks personalized guidance for students at school. Based on the analytical method of exam scores in the common methods, the paper presents the achievement of individual graduation requirements and designs algorithms to dynamically appraise every student with real examples, which may provide detailed data and immediate guidance for the major and its own students. The dynamic appraisal method can improve the GRAs of the major, and also can strengthen the core concepts of engineering education accreditation. © 2020 ACM.

关键词： Students

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Nonstoichiometric Protic Ionic Liquids for Efficient Carbon Dioxide Capture

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SSRN 2023年

作者： Wang, Litian Chen, Jie Li, Dan Li, Cuiping Qian, Lirong Xiong, Yang Xie, Zhiyong Wang, Shuai Zhou, Tongyao Gai, Baojia Wang, Yinuo Tianjin Key Laboratory of Film Electronic and Communication Devices School of Integrated Circuit Science and Engineering Tianjin University of Technology Tianjin300384 China School of Integrated Circuit Science and Engineering Tianjin University of Technology Tianjin300384 China Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin300384 China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of Technology China Tianjin Bohua Yongli Chemical Industry CO. Ltd Tianjin30045 China

Protic ionic liquids (PILs) have emerged as promising solvents for CO2 capture, offering great potential for the development of efficient CO2 absorbents. Understanding the relationship between the PILs’ structures and CO2absorption mechanisms is instructive for advancing their applicability. Herein, an innovative strategy for CO2 capture using nonstoichiometric PILs was demonstrated for the first time. These nonstoichiometric PILs composed of imidazole (Im) as a Brønsted acid and 1,8-diazabicyclo [5.4.0] undec-7-ene (DBU) as a Brønsted base with various ratios. They exhibited both low viscosities and remarkable CO2 loading capacities, reaching up to 0.194 g CO2 /g IL and 1.42 mol CO2 /mol IL at 0.1 atm and 40 °C. The distribution of neutral and ionic species in these nonstoichiometric PILs was determined using density functional theory (DFT) calculations and nuclear magnetic (NMR) spectroscopy analysis. Correlations between the mole ratio of Brønsted acid and base and the viscosities, conductivities, and CO2 absorption properties were observed. The mechanism of CO2 absorption was proposed from the spectral results and DFT calculations. The superior CO2 loading ability of these PILs can be attributed to the formation of the zwitterionic carbamic complexes through interactions between CO2 and the N atom in DBU. Additionally, the presentence of Im significantly avoided the dramatic increase in the viscosity of the absorbents during CO2 absorption. It is believed that the new insights into the CO2 mechanism will facilitate the rational design of PILs for CO2 capture in the future. © 2023, The Authors. All rights reserved.

关键词： Carbon dioxide

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design of an Active Battery Equalization Circuit with DC-DC Converter

Design of an Active Battery Equalization Circuit with DC-DC ...

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IEEE Asia Power and Energy Engineering Conference (APEEC)

作者： Kun Li Xiao Zong Qing Liu Yanfang Sun Fengjun Xue Tianjin Key Laboratory of Film Electronic and Communication Device Tianjin University of Technology Tianjin PR China Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control Tianjin University of Technology Tianjin PR China Wuhan Running Education Research Institute Wuhan PR China

ISBN: (纸本)9781665425513;9781665430791

An active balanced topology circuit based on DC-DC converter is proposed in this paper. It uses the energy of the whole battery pack to charge the lowest voltage cell. In the control strategy, starting and stopping the equalization is well controlled by setting the appropriate thresholds of voltage difference between each cell. Experiment board which can sample and equalize 16 batteries is manufactured, and the experimental results verify the effectiveness of the proposed equalization system.

关键词： Electrical engineering Energy exchange Asia DC-DC power converters Threshold voltage Batteries Topology

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In-Situ Biaxial Cyclic Loading Behavior of Articular Cartilage and its Microstructure Analysis

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SSRN 2022年

作者： Gao, Lilan Feng, Luming Tan, Yansong Liu, Gang Li, Ruixin Gao, Hong Zhang, Chunqiu Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin300384 China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of Technology Tianjin300384 China Tianjin Stomatological Hospital Tianjin300041 China School of Chemical Engineering and Technology Tianjin University Tianjin300350 China

Altered cyclic loading may change the mechanical properties, further inducing damage to articular cartilage. In this study, we studied the biaxial cyclic loading behavior of knee articular cartilage and analyzed the changes of microstructure at fibril level. Firstly, the in-plane biaxial cyclic behaviors of cartilage were investigated with an emphasis on the effects of loading paths to account for complicated loading states in daily activities. The results show that the strain evolution in X-direction is obviously affected by the constraints in Y-direction (orthogonal direction). The loading path has a great influence on the biaxial mean strain, while due to no constraint and the largest stress constraint in Y direction, proportional loading path and uniaxial loading path show the highest and lowest mean strain in X-direction, respectively. Subsequently, the effects of stress amplitude and stress peak holding time on mean strain were probed under square path. It was found that the mean strain of cartilage increases with the increase of stress amplitude or peak stress holding time. In addition, to reveal the inherent deformation mechanism, the collagen fibrils networks before and after biaxial cyclic loading were analyzed. The rearrangement of collagen fibrils networks is related to the stress state of cartilage. Larger stress leads to severer fiber damage in cartilage. © 2022, The Authors. All rights reserved.

关键词： Cartilage

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Weld image dust removal algorithm based on fusion of bright channel and weighted guide dark channel

UPB Scientific Bulletin, Series C: Electrical Engineering an...

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UPB Scientific Bulletin, Series C: Electrical Engineering and Computer Science 2020年第4期82卷 69-80页

作者： Zheng, Qingchun Lu, Kaijie Ma, Wenpeng Zhang, Zhidong Zhu, Peihao Liu, Jingna Hu, Yahui Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin300384 China Tianjin300384 China

The dust removal technology of weld image is helpful to promote the development of weld target detection and tracking control. Aiming at the problem that the image restoration algorithm has halo phenomenon in depth discontinuity and easy to cause color distortion, this paper proposes a single image restoration algorithm based on fusion of bright channel and weighted guided dark channel for dedusting of weld image. Firstly, the bright channel hypothesis is derived according to dark channel priori (DCP), and the bright channel obtained by the adaptive method will fuse with the dark channel image to construct the fusion channel. Then, the weighted guided filter is used to optimize the rough transmittance. Finally, the restored image of the weld is recovered according to the atmospheric scattering model and the restored atmospheric light. Simulation experiments and image quality analysis show that the proposed algorithm can recover the details of the weld image and suppress the halo phenomenon. The image segmentation networks are used to further verify that our algorithm can improve the accuracy and integrity of weld segmentation. © 2020, Politechnica University of Bucharest. All rights reserved.

关键词： Image segmentation

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Finite Element Analysis of Series Elastic Actuator for Exoskeleton Robot Joint 17

Finite Element Analysis of Series Elastic Actuator for Exosk...

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17th IEEE International Conference on mechatronics and Automation, ICMA 2020

作者： Xi, Pengyu Ge, Weimin Zhang, Sen Zhang, Zhili Zielinska, Teresa Tianjin University of Technology Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin300384 China Tianjin Sino-German University of Applied Science Intelligent Manufacturing College Tianjin300384 China Institute of Aeronautics and Applied Mechanics Warsaw University of Technology Warsaw00665 Poland

ISBN: (纸本)9781728164151

The finite element simulation for the joints of an exoskeleton robot is conducted in this paper. Using software OpenSim to simulate the normal walking gait of the human body, the motion angle and moment of the human hip, knee and ankle joints are obtained. Using the obtained data as the input parameters in the finite element simulation of the simulation software Ls-dyna, the strain diagrams and contact force curves of the circular roller and cam disk were obtained. In this study, three commonly used materials are selected: alloy steel, ductile iron and hard aluminum alloy. Finally, the effects of different materials on the key components of the series elastic actuator are studied. © 2020 IEEE.

关键词： Finite element method

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Performance Analysis and Comparison of Different Corrugated Structures and a Novel Alternative Elliptical Twisted Tube in Supercritical Co2 Tower Solar Receivers

SSRN

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SSRN 2022年

作者： Liu, Yun Dong, Yue Li, Tao Zhang, Chuan-Zhi Hebei Key Laboratory of Low Carbon and High Efficiency Power Generation Technology School of Energy Power and Mechanical Engineering North China Electric Power University Baoding071003 China Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering School of Mechanical Engineering Tianjin University of Technology Tianjin300384 China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of Technology Tianjin300384 China

The concentrated solar power generation system with supercritical CO 2 as working medium has high cycle efficiency, which can effectively reduce the volume of heat exchange equipment and reduce the investment cost. However, there is no systematic comparative study on the effect of tube structure on the performance of supercritical CO 2 , but the structure of tubes has a significant effect on the heat transfer performance of supercritical CO 2 , so it is necessary to study it. In this contribution, we firstly analyze the effects of different structures of tubes on the performance of supercritical CO 2 . Then, we design a novel alternative elliptical twisted tube. Finally, we further analyze the effects of the novel tube on the heat transfer performance of supercritical CO 2 by using the field synergy principle. The results show that the novel alternative elliptical twisted tube is the best structure. When the mass flow is 0.08 kg·s - © 2022, The Authors. All rights reserved.

关键词： Solar energy

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design of deep-water omnidirectional spirit level

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Journal of Measurement Science and Instrumentation 2021年第4期12卷 472-478页

作者： ZHAO Lianyu LI Shuo ZHAO Xiaolei LI Maolin CHEN Jinyu WANG Chenglin Tianjin Key Laboratory of Advanced Mechatronic System Design and Intelligent Control National Demonstration Center of Experimental Mechanical and Electrical Engineering EducationSchool of Mechanical EngineeringTianjin University of TechnologyTianjin 300384China Offshore Oil Engineering Co. Ltd.Tianjin 300461China

Attitude adjustment is a key link in the installation process of underwater facilities in deep *** solve this problem,an omnidirectional spirit level for deep water was *** sealing principle of the spirit level and the principle of deep-water pressure resistance are analyzed,and the threaded connection strength is *** mechanical simulation verifies that the spirit level can withstand the pressure of 2000 m water depth,and the water pressure test is carried out for 30 min in a 20 MPa hyperbaric *** the experiment is completed,the appearance of the spirit level is intact and there is no *** experiment results show that the deep-water omnidirectional spirit level can be used in the deep sea within 2000 m.

关键词： deep water omnidirectional spirit level attitude adjustment pressure test underwater pressure

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