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GNN-Assisted BiG-AMP: Joint Channel Estimation and Data Detection for Massive MIMO Receiver

IEEE Transactions on Wireless Communications 2025年

作者： Liu, Zishen Wu, Nan He, Dongxuan Yuan, Weijie Li, Yonghui Quek, Tony Q. S. School of Information and Electronics Beijing Institute of Technology Beijing100081 China School of System Design and Intelligent Manufacturing Shenzhen Key Laboratory of Robotics and Computer Vision Southern University of Science and Technology Shenzhen518055 China School of Electrical and Information Engineering The University of Sydney SydneyNSW2008 Australia Singapore University of Technology and Design 487372 Singapore Department of Electronic Engineering Kyung Hee University Yongin17104 Korea Republic of

In this paper, we develop a graph neural network (GNN)-assisted bilinear inference approach to enhance the receiver performance of the MIMO system through message passing-based joint channel estimation and data detection (JCD). Specifically, based on the bilinear generalized approximate message passing (BiG-AMP) framework and conditional correlation of signal, we propose a GNN-assisted BiG-AMP (GNN-BiGAMP) approach, which integrates a GNN module into the data-detection-loop to compensate the inaccurate marginal likelihood approximation. By leveraging the coupling between the channel and received symbols, a bilinear GNN-assisted BiG-AMP (BiGNN-BiGAMP) JCD receiver is further proposed. This method incorporates two GNNs with similar graph representation into the bilinear posterior estimation loops, which not only compensates for approximation errors but also alleviates performance loss due to premature variance convergence, thereby enhancing the receiver performance significantly. To fully exploit the supervised information from channel estimation and data detection, we propose a multitask learning based training scheme, which coordinates GNNs with different tasks in two loops. Simulation results show that our proposed GNN-assisted JCD receivers significantly outperform other JCD counterparts in terms of both channel estimation and data detection. © 2025 IEEE. All rights reserved.

关键词： Graph neural networks

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A Peridynamic Approach for the Evaluation of Metal Ablation under High Temperature

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Computer Modeling in Engineering & sciences 2023年第3期134卷 1997-2019页

作者： Hui Li Liping Zhang Yixiong Zhang Xiaolong Fu Xuejiao Shao Juan Du Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of ChinaChengdu610200China

In this paper,the evaluations of metal ablation processes under high temperature,i.e.,the Al plate ablated by a laser and a heat carrier and the reactor pressure vessel ablated by a core melt,are studied by a novel peridynamic *** all,the peridynamic formulation for the heat conduction problem is obtained by Taylor’s expansion ***,a simple and efficient moving boundary model in the peridynamic framework is proposed to handle the variable geometries,in which the ablated states of material points are described by an additional scalar ***,due to the automatic non-interpenetration properties of peridynamic method,a contact algorithm is established to determine the contact relationship between the ablated system and the additional heat *** addition,the corresponding computational procedure is listed in ***,several numerical examples are carried out and the results verify the validity and accuracy of the present method.

关键词： Peridynamics metal ablation moving boundary model contact algorithm reactor pressure vessel

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A numerical method for predicting bursting strength of composite rocket motor case considering filament winding process-induced stress

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Chinese Journal of Aeronautics 2025年第2期 509-522页

作者： Jiqiu LIANG Fei ZHAO Dan WU Anxin DING Hubei Key Laboratory of Advanced Aerospace Propulsion Technology System Design Institute of Hubei Aerospace Technology Academy School of Materials Science and Engineering Wuhan University of Technology State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology

A numerical method to predict the bursting strength of filament wound composite rocket motor case is proposed here. This method can evaluate the longitudinal stress evolution of each composite layer as impregnated filaments with fiber tension are wound layer by layer, and consider the effects of accumulated stress and deformation during filament winding on the bursting strength of composite case. Taking ?520 mm composite cases as a case study, the filament-winding-processinduced stress and deformation as well as progressive damage behavior are numerically predicted,followed by a comparison with experimental results. The numerical results show that the predicted bursting pressures for composite cases manufactured on the mandrels with and without a flexible component are 14.20 MPa and 21.40 MPa, respectively. These values exhibit slight deviation from the measured pressures of 13.50 MPa and 21.57 MPa. Moreover, the predicted damage locations,situated respectively in the dome and cylinder, agree well with the experimental observation. These observations indicate that use of flexible component reduces the load-bearing capacity of the ***, it validates the reliability and accuracy of the proposed numerical method in predicting the bursting strength of composite cases.

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Experimental research on the startup and shutdown heat transfer behavior of the coupling system of multi-stage heat pipes and radiators

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Annals of Nuclear Energy 2025年 222卷

作者： Liu, Limin Du, Zhengyu Guo, Ziang Liu, Ziyin He, Xiaoqiang Gu, Hanyang School of Nuclear Science and Engineering Shanghai Jiao Tong University China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China China

The heat pipe cooled reactor (HPR) offers high safety and compactness for space applications. This study experimentally investigates the coupled transient thermal behavior of the primary sodium heat pipe, thermoelectric generator (TEG), and secondary potassium heat pipe radiators during startup and shutdown. The primary heat pipe reached ∼700 °C at the evaporator within 3 h, while the secondary radiators exhibited delayed activation, with most condensing sections exceeding 299 °C after 21 h. A sonic limit effect caused local thermal and pressure drops at 800 mm. 75–80 % of input power was dissipated radiatively, exhibiting a thermal lag due to system inertia. During shutdown, the primary heat pipe responded rapidly to power reduction, while secondary heat pipe radiators showed accelerated cooling after passing their transition temperature. Stepwise power reductions led to faster temperature drops in the primary pipe than constant-rate reduction conditions. These results offer insights into HPR thermal dynamics for space system design. © 2025 Elsevier Ltd

关键词： Space applications

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Positioning Control for Voice Coil Motor Using Unbalanced Multilevel Inverter Topology

Positioning Control for Voice Coil Motor Using Unbalanced Mu...

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International Conference on Mechatronics (ICM)

作者： Gaku Takei Hidemine Obara Ryo Haneda Takahiro Nozaki Graduate School of Science and Technology Keio University Yokohama Japan Department of Physics Electrical and Computer Engineering Yokohama National University Yokohama Japan Department of System Design Engineering Keio University Yokohama Japan

ISBN: (数字)9798331533892

ISBN: (纸本)9798331533908

This article proposes a new multi-level inverter (MLI) based on flying capacitor inverter (FCI), with focused on high-precision positioning control for a voice coil motor (VCM). Multi-level inverters (MLIs) have the characteristic that increasing the number of output voltage levels reduces the output voltage error. However, as the number of levels increases, the number of circuit elements increases, and the circuit becomes more complex. In addition, the output voltage amplitude for each level is constant in conventional inverters. As a result, such as high-precision positioning control of VCM, designing an appropriate inverter for a reference wave that contains a large amount of low-voltage components increases the number of circuit elements. Therefore, this paper proposes a MLI with two unbalanced dc-input voltages, referred to as unbalanced MLIs (UMLIs) hereinafter. This topology uses two different dc-input voltages, and it is possible to reduce the output voltage level in extremely low-voltage range compared to other voltage levels. Simulation results when the high-precision positioning control of the VCM confirm that the proposed UMLIs improves the control performance compared to the conventional FCIs with equal number of output voltage levels and uniform level widths.

关键词： Coils Low voltage Simulation Switches Multilevel inverters Motors Topology Sensors Voltage control Motion control

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Study on hydrogen stratification and erosion process in Chinese SMR containment under severe accident scenario

引用

International Journal of Advanced Nuclear reactor design and technology 2020年 2卷 43-51页

作者： Fan, Yang Songwei, Li Wei, Zeng Zhifang, Qiu Jian, Deng Science and Technology on Reactor System Design Technology Laboratory NPIC China Design and Research Sub-institute NPIC China

During postulated severe accident, large amount of hydrogen-vapor mixture will be released into the containment and inflammable gas mixture may form. Once the gas will be ignited, the generated pressure loads can jeopardize the integrity of the internal structures. As the local accumulation of high content hydrogen related much to the stratification and erosion mechanism, it is therefore of interest whether a stratification of gas layers will form within small containment. In this study, a stratification/erosion experiment is performed and the criteria under which the steady stratification will be destroyed by steam jet discussed. Then the simulation method is validated by the experimental data. At last, several severe accident scenarios for Chinese SMR performed and one of them is adopted for containment hydrogen CFD analysis. It is shown that high content of hydrogen will form in the upper part of the containment, and clear gas stratification will form, such stratification will be enhanced due to the condensation effect of steel containment wall. © 2020

关键词： Hydrogen

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Experimental study on aerosol behavior in water pool scrubbing under severe accident conditions

引用

International Journal of Advanced Nuclear reactor design and technology 2020年 2卷 111-116页

作者： Xu, Youyou Deng, Jian Zou, Zhiqiang Jiang, Guangming Wu, Xiaoli Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu China

In severe accident of nuclear power plant, large quantities of steam and radioactive aerosol may release to the containment. Meanwhile, hydrogen may be generated by zirconium-steam reaction and released to the containment and mixed with steam and air to form a flammable mixture (H2, H2O, Air) which might combust even explode to generate mechanical and thermal load on containment. In this situation, timely containment venting strategies (CVS) is an important and effective measure to release the containment atmosphere to decrease the pressure. In order to remove the radioactive aerosol particles and cool the high temperature mixture, the containment atmosphere are vented to the water pool. This paper mainly investigated the behavior of aerosol scrubbing in water pool. The effects of submergence depth, aerosol particle diameter and aerosol concentration were preliminary studied by conducting a series of experiments. The results illustrate that the scrubbing efficiency of gas jet injection into water pool almost larger than 90%. And the aerosol particle diameter and submergence depth have significant influence on decontamination factor (DF). This paper provide data basis and reference to the subsequent work. © 2020

关键词： Aerosols

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Investigation into the flow and heat transfer characteristics in liquid metal cooled narrow rectangular channel with rough surfaces

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Case Studies in Thermal Engineering 2025年 72卷

作者： Xue Zhang Wenpei Feng Xiaolong Yang Hongxing Yu Jian Deng Sijia Du Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu 610213 China College of Nuclear Technology and Automation Engineering Chengdu University of Technology Chengdu 610059 China

This study investigates the impact of roughness elements on fluid flow and heat transfer characteristics in narrow rectangular channels. The results show that when the fluid flows over roughness elements, it induces vortices near the wall, disturbing the flow and heat transfer boundary layers. This enhances heat transfer while simultaneously increasing flow resistance. Among different roughness types, cylindrical roughness elements demonstrate a more substantial improvement in both heat transfer efficiency and friction factor compared to cubic elements. The Nusselt number is found to be non-monotonic related to the height of the roughness elements, while the friction factor increases with height. Additionally, larger roughness element diameters lead to higher Nusselt numbers and friction factors. Further analysis reveals that under conditions where the spacing and height remain unchanged, an increase in the roughness elements quantity results in a diminished enhancement of heat transfer. The base edge length of the roughness elements has a more significant impact on heat transfer capacity than the additional heated area, while the additional area primarily affects the flow resistance, causing the friction factor to increase with the number of roughness elements.

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Deformation Analysis and Prediction of Drop-Stitch Reinforced Inflatable Robot Link for 1DOF and 2DOF Motion

Deformation Analysis and Prediction of Drop-Stitch Reinforce...

引用

IEEE/SICE International Symposium on system Integration

作者： Gangadhara Naga Sai Gubbala Masato Nagashima Hiroki Mori Young Ah Seong Hiroki Sato Ryuma Niiyama Yuki Suga Tetsuya Ogata Dept. of Intermedia Art and Science School of Fundamental Science and Eng. Waseda University Tokyo Japan Institute for AI and Robotics Future Robotics Organization Waseda University Tokyo Japan Dept. of System Design Faculty of Eng. and Design Hosei University Tokyo Japan School of Project Design Miyagi University Miyagi Japan School of Science and Technology Meiji University Tokyo Japan Waseda Research Institute for Science and Engineer- ing (WISE) Waseda University Tokyo Japan National Institute of Advanced Industrial Science and Technology (AIST) Tokyo Japan

ISBN: (数字)9798331531614

ISBN: (纸本)9798331531621

In this study, we observe the dynamic behavior of an inflatable robot arm with an internally reinforced drop-stitch structure. We examine the deformation during motion of 1 and 2 degrees of freedom (DOF) for an inflatable body. The inflatable robot arm has a soft inflatable body as links and rigid servo actuators as joints. We implemented a sinusoidal motion for inflatable links for various payload conditions and analyzed them using a Motion Capture system. To estimate the dynamic deformation of the balloon in motion, we have defined a Deformation Index (DI) metric. Angle, current of the actuator (servo), and DI are used as input to polynomial regression to predict the end effector position. With this analysis, we can understand the complexity of modeling the nonlinear behavior of inflatable links for multi-DOF motion. We observed DI helps improve the prediction of the end effector position by including deformation information. However, the results demonstrate the limitations of polynomial regression analysis of an internally reinforced inflatable robot arm link.

关键词： Actuators Deformation Dynamics system integration Arms Polynomials End effectors Regression analysis Servomotors Payloads

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Advancements in the research of high-temperature gas-cooled reactor fuel via additive manufacturing techniques

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International Journal of Advanced Nuclear reactor design and technology 2024年第1期6卷 14-20页

作者： Liao, Haoyu Zhang, Ting Li, Chenxi Tang, Changbin Li, Yuanming Chen, Ping Nuclear Power Institute of China Science and Technology on Reactor System Design Technology Laboratory Chengdu610200 China

Recent advances in high-temperature gas-cooled reactor fuel research have captured the global spotlight, as modern operating contexts demand innovative responses to unprecedented challenges. This article offers an overview of contemporary directions in high-temperature gas-cooled reactor fuel design worldwide, pinpointing the shared operational demands and development patterns characteristic of these advanced fuels. It presents an innovative advanced fuel design, which incorporates multi-layer coated particles to boost safety and employs high-temperature-resistant silicon carbide (SiC) ceramics, seamlessly integrated with cutting-edge additive manufacturing (AM) techniques. This design heralds a shift toward modular fuel element solutions that are easily scalable, supporting the diverse array of advanced reactors and marking a significant step forward in the quest for high-temperature gas-cooled reactor fuel technologies. © 2024 Xi'an Jiaotong University

关键词： Silicon carbide

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