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International Conference on Mechatronics and Machine Vision in Practice (M2VIP)

作者： Teng Zhang Hao Sun Lin Zhou Shengqiang Zhao Fangyu Peng Rong Yan National NC System Engineering Research Center School of Mechanical Science and Engineering Huazhong University of Science and Technology Wuhan China Wuhan Digital Design and Manufacturing Innovation Center Co. Ltd China Wuhan China State Key Laboratory of Digital Manufacturing Equipment and Technology School of Mechanical Science and Engineering Huazhong University of Science and Technology Wuhan China

ISBN: (纸本)9781665431545

Machining error is one of the most important indicators to evaluate the processing quality of thin-walled parts. With the development of Data science, the data-driven methods have become popular. But the condition that the model can work accurately on a new task is that the feature space and distribution of the data are the same. A sample-based transfer learning method driven by geometric position is utilized to quickly predict the machining errors of thin-walled parts under different working conditions. This method can fully learn the knowledge related to machining errors contained in the data through model training, and can apply this knowledge to accurately and quickly forecast machining errors under new working conditions. In the experimental scenario, this method has outstanding predictive performance. The average determination coefficient of the four groups of target domain experiments reached 0.96, and the average root mean square error is less than the machining error acquisition time to 22% of the original, reducing the dependence on time-consuming and expensive measurements greatly.

关键词： Employee welfare Training Mechatronics Transfer learning Machining Predictive models Data models

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Research on Optimization of Key Parts of Nuclear reactor Based on Finite Element Simulation

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IOP Conference Series: Earth and Environmental science 2021年第3期632卷

作者： Bo Yang Tianda Yu Qiang Deng Cong Chen Fengshou Zhang Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institution of China Sichuan ChengDu 610041 China

In view of the higher technical requirements of the third generation PWR for the control rod drive mechanism (CRDM), China's third generation nuclear reactor CRDM hook parts are designed to multi-tooth hook with wear-resistant surfacing. The surfacing welding process is simulated and optimized based on finite element simulation, and reasonable welding process and parameters are determined by simulation results in this *** to the optimized welding process, the parts are trial-produced, and the parts of the hook are subjected to metallographic inspection, hardness test and thermal life test. The results show that the optimized hook parts have high hardness and wear resistance, and meet the requirements of the third generation PWR nuclear power plant.

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A hybrid mechanism-based and data-driven approach for the calibration of physical properties of Ni-based superalloy GH3128*

A hybrid mechanism-based and data-driven approach for the ca...

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International Conference on Mechatronics and Machine Vision in Practice (M2VIP)

作者： Hao Sun Lin Zhou Shengqiang Zhao Teng Zhang Fangyu Peng Rong Yan National NC System Engineering Research Center School of Mechanical Science and Engineering Huazhong University of Science and Technology Wuhan China Wuhan Digital Design and Manufacturing Innovation Center Co. Ltd China Wuhan China State Key Laboratory of Digital Manufacturing Equipment and Technology School of Mechanical Science and Engineering Huazhong University of Science and Technology Wuhan China

ISBN: (纸本)9781665431545

Within the finite element simulation model of metal manufacturing processes, the setting of physical properties of the materials will significantly affect the final simulation results. In this paper, a hybrid approach to integrate mechanical models and experimental data is proposed to identify the constitutive parameters and tool-chip friction coefficient of superalloy GH3128. Firstly, mechanical model is established and the relation between the constitutive parameters and the measured shear flow stress is determined. Combined with Bayesian inference, the fast inverse identification of the above parameters is realized. Then, a finite element surrogate model and Bayesian framework are fused for calibrating tool-chip friction coefficient. Finally, the effectiveness of the proposed approach is verified through milling experiments. The prediction accuracy of the prediction model are significantly improved by considering the uncertainties of physical properties. The relative error of the model in direction and direction are 11.4681% and 4.2989%, respectively.

关键词： Uncertainty Friction Simulation Metals Milling Predictive models Finite element analysis

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Tool wear parameters identification in precision milling using a hybrid model combining cutting forces analytical model and Gaussian process regression method*

Tool wear parameters identification in precision milling usi...

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International Conference on Mechatronics and Machine Vision in Practice (M2VIP)

作者： Shengqiang Zhao Lin Zhou Hao Sun Fangyu Peng Rong Yan Teng Zhang National NC System Engineering Research Center School of Mechanical Science and Engineering Huazhong University of Science and Technology Wuhan China Wuhan Digital Design and Manufacturing Innovation Center Co. Ltd China Wuhan China State Key Laboratory of Digital Manufacturing Equipment and Technology School of Mechanical Science and Engineering Huazhong University of Science and Technology Wuhan China

ISBN: (纸本)9781665431545

In precision milling, tool wear has a significant impact on tool life prediction, machining accuracy and surface quality evaluation of workpiece. Tool wear pattern generally includes the increase of the tool flank wear width, as well as the expansion of the edge radius in precision process. Therefore, two tool wear parameters in precision milling have been generalized in this paper. The milling cutting force analytical model considering tool wear is set up to generate the data related to cutting force and tool wear parameters, which can be used as the dataset to construct and train the Gaussian process regression model. Finally, the trained regression model can output the prediction of tool flank wear width and edge radius as measured cutting forces treated as input values, which is helpful to realize the online monitoring of tool wear in the processing site environment. Consequently, the average relative prediction errors of tool flank wear width and edge radius are controlled within 2%, with the prediction time within 100ms.

关键词： Training Analytical models Parameter estimation Machine learning algorithms Force Milling Gaussian processes

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Time-varying Characteristics of mmWave Channel based on the Clustered Sparsity Model

Time-varying Characteristics of mmWave Channel based on the ...

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IEEE Conference on Vehicular technology (VTC)

作者： Lijun Yang Haitao Lu Xinchao Ge Zhixin Sun Pan Cao School of Internet of Things Nanjing University of Posts and Telecommunications Nanjing China RAN System Design Dept. ZTE Corporation Shenzhen China Shenzhen Key Laboratory of 5G RAN Security Technology Research and Application Shenzhen China School of Modern Posts Nanjing University of Posts and Telecommunications Nanjing China School of Physics Engineering and Computer Science University of Hertfordshire Hatfield UK

A better understanding of the mmWave channel coherence time will play a significant role in both communication and sensing. Traditional literatures consider that the channel coherence time in mmWave communication will be very short due to high frequency, which makes the channel estimation more difficult. However, we believe that the propagation characteristics of the mmWave channel will affect its coherence time, i.e., channel sparsity may limit its time variability. In this paper, we investigate the time-varying nature of mmWave channel by analyzing its Doppler spread based on the clustered sparsity model. After the derivation of Doppler spectrum DPS and the simulation analysis based on the two-cluster channel, we found that the maximum angle between clusters and the power distribution between clusters are two main factors limiting the Doppler spread. Finally, the realistic mmWave NYUSIM model is used for Doppler spread comparative analysis with Clarke’s model and find that Doppler spread of NYUSIM channel is far less than that estimated based on Clarke’s model. Thus, it is demonstrated that even if the mmWave frequency is high, the clustered sparsity characteristics makes its channel coherence time not as short as thought intuitively, which is meaningful for mmWave vehicular sensing and communication.

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Investigations on the Two-Phase Flow and Heat Transfer Behaviors in a Central Uniform Dispersion-Type Heat Exchanger

SSRN

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SSRN 2022年

作者： Guo, Qi Liu, Huan-Ling Xie, Gongnan Guo, Chao Shao, Xiao-Dong Shaanxi Key Laboratory of Space Solar Power Station System School of Electromechanical Engineering Xidian University Xi'An710071 China Key Laboratory of Electronic Equipment Structure Design Ministry of Education School of Electromechanical Engineering Xidian University Xi'An710071 China School of Marine Science and Technology Northwestern Polytechnical University Xi’an710072 China

In order to improve the temperature uniformity of multiple chips, a central uniform distributed heat exchanger (CUD) is designed. Firstly, using ethanol solution as coolant, the cooling ability of the heat exchanger is numerically investigated by using VOF gas-liquid two-phase flow model, and the two-phase flow experimental system is established to verify the correctness of the numerical results. The results verifies the accuracy of the numerical simulation method. Secondly, the two-phase flow boiling heat transfer behavior are compared with that of single-phase flow with water as coolant. The results show that with the increase of inlet flow, the thermal resistance and average temperature of two-phase flow change less than that of single-phase flow. This indicating that two-phase flow has better advantages in improving the temperature uniformity of multiple heat sources. Thirdly, the heat transfer characteristics of radiators with different Wi are studied. Finally, the prediction functions of the boiling heat transfer coefficient and pressure drop is established, and the multi-objective genetic algorithm is used to obtain the best parameters of this heat exchanger.. Furthermore, the heat dissipation of the optimized heat exchanger design is studied numerically. The simulated results are in good agreement with the optimization results. © 2022, The Authors. All rights reserved.

关键词： Two phase flow

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Effect of variable stroke on combustion characteristics and stability of a free-piston engine generator

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Applied Thermal Engineering 2025年 277卷

作者： Liu, Chang Jia, Boru Liu, Zhen Zhang, Zhiyuan Hu, Xiaoxu Wei, Shuojian Ma, Yuguo School of Mechanical Engineering Beijing Institute of Technology Beijing 100081 China Hubei Key Laboratory of Power System Design and Test for Electrical Vehicle Hubei University of Arts and Science Xiangyang 441053 China

The free-piston engine generator (FPEG) features a variable stroke structure, offering significant advantages in multi-fuel adaptability and high-efficiency combustion technologies. Stroke control and design directly affect combustion regulation and system performance, and thus represent a key challenge in FPEG development. Existing studies on stroke variation mostly rely on numerical simulations, often neglecting fuel short-circuit losses and lacking experimental validation of actual combustion performance and stability. In this study, an experimental approach was employed to investigate the effects of stroke length variation (47–55 mm) on the combustion characteristics, system performance, and operational stability of an FPEG. The results show that shortening the stroke reduced the indicated work by 4.3 % from 55 mm to 47 mm, but increased the operating frequency by 14.7 %, resulting in a 10 % improvement in indicated power. Moreover, shorter stroke lengths enhanced both indicated thermal efficiency and fuel economy, with the indicated thermal efficiency increasing by 19.6 % and the minimum ISFC reaching 336 g/(kW·h). In terms of stability, the short-stroke configuration markedly reduced cycle-to-cycle variations in both combustion and system operation: COVPmax and COVIMEP decreased by 34.5 % and 50.6 %, respectively, while COVf dropped to 0.59 %.This study is the first to experimentally reveal the influence of stroke variation on FPEG performance, providing valuable data support for structural optimization and performance control of FPEG systems.

关键词： Combustion characteristics Engine performance Free-piston engine generator Stability Variable stroke

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Beyond biochemical patterning: How mechanical bistability governs robust organoid morphogenesis

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Mechanobiology in medicine 2025年第2期3卷 100134页

作者： Qigan Gao Yuehua Yang Haoxiang Yang Hongyuan Jiang CAS Key Laboratory of Mechanical Behavior and Design of Materials CAS Center for Excellence in Complex System Mechanics Department of Modern Mechanics University of Science and Technology of China Hefei Anhui 230026 China.

Understanding the regulatory mechanisms of intestinal organoid morphogenesis remains a fundamental challenge in organoid biology. Emerging evidence highlights mechanical bistability as a critical regulator, mediated by dynamic lumen-actomyosin feedback. The recently developed 3D vertex model demonstrates that crypt curvature modulates actomyosin localization via mechanosensitive pathways, creating two stable morphological states-bulged or budded-depending on mechanical history. This model advances beyond static vertex models by incorporating epithelial thickness variations and lumen pressure effects, explaining previously unresolved phenomena like irreversible crypt budding and snap-through transitions. The findings establish a new framework for understanding mechanical decision-making in epithelial tissues, with implications for organoid engineering and developmental biology.

关键词： Epithelial mechanics Intestinal organoids Mechanical bistability Morphogenesis Vertex model

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Boron concentration field measurement and mixing analysis in the annular downcomer of reactor pressure vessel 27

Boron concentration field measurement and mixing analysis in...

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27th International Conference on Nuclear Engineering: Nuclear Power Saves the World!, ICONE 2019

作者： Zhang, Qi Tan, Sichao Zhao, Hangbin Wang, Peng Gu, Hanyang Yang, Yunjia School of Nuclear Science and Engineering Shanghai Jiao Tong University Shanghai China Fundamental Science on Nuclear Safety and Simulation Technology Laboratory Harbin Engineer University Harbin Heilongjiang China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu China

ISBN: (纸本)9784888983051

In nuclear power plant, the reactor annular downcomer acts as the upstream of the reactor core, and boric distribution inside the downcomer is focused in the ECC situation. The relevant study indicates that the inlet coolant does not flow along annular channel directly, and the current multi primary loops layout makes the fluid mixing of the downcomer far more complex. In this paper, boron transport and mixing phenomenon inside the reactor annular downcomer were analyzed by Laser Induced Fluorescence (LIF) method, a reduziertreduced RPV model was built with transparent material, the boric acid was equivalently simulated by rhodamine B. The single loop and double loops flow mixing tests were respectively performed, the qualitative and quantitative data at cross sections were acquired. For the single loop test, the injected tracer transported along the circumferential position and was constantly diluted by the ambient pure water;meanwhile, a portion of the injection entered the lower space and filled up the annular channel in the same manner. From the time evolution of concentration gradient distribution, the increasement of inlet velocity is favorable to the uniform mixing. For the double loops fluid mixing tests, the tracer solution and pure water were injected into the model simultaneously through two independent entrances. The location of the intersection boundary of the two fluids was affected by the entrance momentum ratio, and the tracer distribution fluctuated remarkably in the lower space of the downcomer. Copyright © 2018-2019 by JSME

关键词： Boric acid

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Towards Secure Semantic Transmission In the Era of GenAI: A Diffusion-based Framework

arXiv

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arXiv 2025年

作者： He, Boxiang Chen, Zihan Luo, Junshan Liu, Chuanhong Wang, Shilian Wang, Fanggang Quek, Tony Q.S. College of Electronic Science and Technology National University of Defense Technology Changsha410073 China Information Systems Technology and Design Singapore University of Technology and Design Singapore Beijing Key Laboratory of Network System Architecture and Convergence School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing100876 China School of Electronic and Information Engineering Beijing Jiaotong University Beijing100044 China

Semantic communication, due to its focus on the transmitting meaning rather than the raw bit data, poses unique security challenges compared to the traditional communication systems. In particular, semantic communication systems are vulnerable to the malicious attacks that focus on the semantic layer, with the intention of understanding or distorting the intended meaning of the transmitted privacy data. Diffusion models, a class of generative artificial intelligence (GenAI), are well-suited for ensuring data security to attack. Through iteratively adding and then removing noise, diffusion models can generate meaningful information despite the presence of the unknown noise. This article proposes a diffusion-based framework to enhance the security of semantic transmission for the attacks including eavesdropping and jamming. Specifically, the proposed framework incorporates both the artificial noise and natural channel noise into the forward process of the diffusion models during the semantic transmission, with the reverse process used to remove noise at the legitimate receiver. In the eavesdropping scenarios, the artificial noise is the friendly noise designed to prevent semantic eavesdropping. In the jamming scenarios, the artificial noise is the malicious jamming generated by the jammer, which disrupts the semantic transmission. The case studies show that the proposed diffusion-based framework is promising in securing the semantic transmission. We also consolidate several broad research directions associated with the proposed framework. Copyright © 2025, The Authors. All rights reserved.

关键词： Electroosmosis

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