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Classification of inelastic deformation and material-intrinsic indices about mechanical performance of general solid matter

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Science China(Physics,Mechanics & Astronomy) 2023年第11期66卷 155-178页

作者： Yichao Zhu shaoshuai Li Biao Wang Department of Engineering Mechanics Dalian University of TechnologyDalian116024China State Key Laboratory of Structural Analysis Optimization and CAE Software for Industrial EquipmentDalian University of TechnologyDalian116024China School of Physics and Sino-French Institute of Nuclear Engineering and Technology Sun Yat-sen UniversityGuangzhou510275China Research Institute of Interdisciplinary Science Dongguan University of TechnologyDongguan523808China

The present article is aimed to detect material-intrinsic indices that can be used to supervise the mechanical performance of general solid *** novelty carried in this article can be summarised as ***,an inelastic deformation state of almost any solid matter can be treated as the combination of two fundamental modes due to different microscopic causation:Mode I inelastic distortion due to the movement of sliding types of defects and Mode II inelastic dilation due to the evolution of voids/***,each inelastic deformation mode is characterised by a single principal inelastic deformation descriptor(PIDD):Mode I by a newly introduced quantity of maximum distortional angle changeαand Mode II by the logarithm of dilating magnificationω.In particular,the concept of maximum distortional angle change gives rise to a geometrically intuitive yield criterion ofα>α_(c),which in situations of small deformation,is shown to asymptote von Mise's,and to become Tresca's in cases of plane ***,the deformation process of a solid matter under monotonic and ambient loads is formulated by means of trajectories of thermodynamic equilibria with respect to the PIDD *** a pair of physical quantities which measure the stresses needed to change the local PIDD state are singled *** termed as inelastic deformation resistances(IDRs),these two quantities are shown to depend only on the onsite atomic *** is also shown that key descriptive properties about the mechanical behaviours of materials,such as ductility,are encoded in IDRs as functions of *** the IDR pair may serve as material performance indices that may be more intrinsic than conventional stress-strain relationships.

关键词： inelastic deformation modes mechanical performance index thermodynamic principal inelastic deformation descriptor inelastic deformation resistance

Federated Reinforcement Learning with Adaptive Training Times for Edge Caching

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China Communications 2022年第8期19卷 57-72页

作者： shaoshuai Fan Liyun Hu Hui Tian State Key Laboratory of Networking and Switching Technology Beijing University of Posts and TelecommunicationsBeijing 100876China

To relieve the backhaul link stress and reduce the content acquisition delay,mobile edge caching has become one of the promising *** this paper,a novel federated reinforcement learning(FRL)method with adaptive training times is proposed for edge *** a new federated learning process with the asynchronous model training process and synchronous global aggregation process,the proposed FRL-based edge caching algorithm mitigates the performance degradation brought by the non-identically and independently distributed(noni.i.d.)characteristics of content popularity among edge *** theoretical bound of the loss function difference is analyzed in the paper,based on which the training times adaption mechanism is proposed to deal with the tradeoff between local training and global aggregation for each edge node in the *** simulations have verified that the proposed FRL-based edge caching method outperforms other baseline methods in terms of the caching benefit,the cache hit ratio and the convergence speed.

关键词： edge caching federated reinforcement learning(FRL) non-identically and independently distributed(non-i.i.d.)

Towards Practical Distributed Video Coding for Energy-Constrained Networks

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Chinese Journal of Electronics 2016年第1期25卷 121-130页

作者： CAO Yue GAO shaoshuai ZHANG Can QIU Gengfeng School of Electronic Electrical and Communication Engineering University of Chinese Academy of Sciences

Most of current distributed video codecs are developed based on the structure of Stanford scheme that employs channel coding like LDPC and Turbo ***, they need many times of iteration and feedback,which bring high decoding complexity and latency that make them less practical in energy-constrained *** this paper, a new distributed video codec based on modulo operation in the pixel domain is proposed, which only needs one feedback request and has a much lower decoding complexity. Mathematical proof of the equivalence between modulo operation and coset partition in the M-ary field is given, which means that the modulo operation in the M-ary field is a good substitute for channel codes in the distributed video coding systems. A system is built based on the proposed scheme. Simulation results show that the proposed scheme outperforms the state-of-the-art distributed video codecs with the decoding complexity as low as 1% to 10% of them.

关键词： Distributed video coding Modulo operation Coset codes Side information

Pseudo-Channel Matrix Truncation Based Spatial Correlation Mitigation in Massive MIMO

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China Communications 2021年第9期18卷 130-147页

作者： Yitian Chen shaoshuai Gao Guofang Tu Hao Qiu School of Electronic Electrical and Communication Engineeringthe University of Chinese Academy of SciencesBeijing 101408China

Massive multiple-input multiple-output(MIMO),a technique that can greatly increase spectral efficiency(SE)of cellular networks,has attracted significant interests in recent *** of the major limitations of massive MIMO systems is pilot contamination,which will deteriorate the *** superimposed pilot-based scheme has been proved to be a viable method for pilot contamination ***,it cannot break through another limitation of massive MIMO,i.e.,spatial *** addition,it will also lead to interference between the pilot and user data since they are imposed *** this paper,we try to tackle these two issues,which will be described as ***,a column-wise asymptotically orthogonal matrix,named as pseudo-channel matrix,is developed by orthogonalization of received *** recover the information about the large-scale fading(LSF)coefficients,the pseudo-channel matrix is truncated according to the cardinality of adjacent users set(CAUS).By this means,spatial correlation can be mitigated ***,robust independent component analysis(RobustICA)is used to reduce the interference caused by user data,and as a result the system performance can be further *** simulation results demonstrate the effectiveness of the proposed method.

关键词： massive MIMO pilot contamination pseudo-channel matrix spatial correlation superim-posed pilots.

Beidou receiver based on anti-jamming antenna arrays with self-calibration for precise relative positioning

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Journal of Systems Engineering and Electronics 2024年第5期35卷 1132-1147页

作者： AN Yi KANG Ronglei BAN Yalong YANG shaoshuai The 10th Research Institute China Electronics Technology Group CorporationChengdu 610036China

Unmanned aerial vehicles(UAVs)may be subjected to unintentional radio frequency interference(RFI)or hostile jamming attack which will lead to fail to track global navigation satellite system(GNSS)***,the simultaneous realization of anti-jamming and high-precision carrier phase difference positioning becomes a dilemmatic *** this paper,a distortionless phase digital beamforming(DBF)algorithm with self-calibration antenna arrays is proposed,which enables to obtain distortionless carrier phase while suppressing ***,architecture of high precision Beidou receiver based on anti-jamming antenna arrays is ***,the performance of the algorithm is evaluated,including antenna calibration accuracy,carrier phase distortionless accuracy,and carrier phase measurement accuracy without ***,the maximal jamming to signal ratio(JSR)and real time kinematic(RTK)positioning accuracy under wideband jamming are also *** experimental results based on the real-life Beidou signals show that the proposed method has an excellent performance for precise relative positioning under jamming when compared with other anti-jamming methods.

关键词： Beidou receiver antenna array anti-jamming high precision distortionless carrier phase

Temperature Fluctuation of a Closed-Cycle Helium Joule-Thomson Cryocooler with Two-Stage Precooling

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Journal of Thermal Science 2023年第4期32卷 1501-1511页

作者： CHEN Zhichao CUI Xiaoyu LIU shaoshuai WU Yinong JIANG Zhenhua DING Lei School of Energy and power Engineering University of Shanghai for Science and TechnologyShanghai20093China Shanghai Institution of Technology and Physics Chinese Academy of SciencesShanghai200083China

For quantum communications,single-photon detection,millimeter wave detection and other space projects,all of them need to work at liquid helium temperatures to achieve excellent *** closed-cycle helium Joule-Thomson cryocooler(JTC)is currently one of the mainstream solutions to realize the liquid helium *** realizing the liquid helium temperature,the detector has strict requirements on the temperature fluctuation of the JTC,because the thermal noise caused by the JTC temperature fluctuation will have a critical impact on the detection *** typical closed-cycle helium JTC is precooling by a two-stage *** the operating parameters of the JTC compressor remain unchanged,the change of the precooler is the main factor that affects the temperature fluctuation of the *** explore the influence mechanism of JTC temperature fluctuations,experimental and theoretical studies are carried *** on the real gas equation of state,the influence of various parameters on the evaporator temperature fluctuations is *** results show that the increase in temperature of each stage will cause the temperature of the JTC to ***,the change of the secondary precooling temperature(T_(pre2))has the most obvious influence on JTC ***,the influence of the JT compressor’s buffer tank volume Vb on temperature fluctuation is *** increasing the Vb,the JTC temperature fluctuation caused by the temperature change of the precooler can be effectively reduced.

关键词： temperature fluctuation liquid helium temperature Joule-Thomson cryocooler precooling temperature

Mitigation of blackout problem for reentry vehicle in traveling magnetic field with induced current

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Plasma Science and Technology 2020年第12期22卷 37-47页

作者： shaoshuai GUO Kai XIE Bin SUN Shaowei LIU School of Aerospace Science and Technology Xidian UniversityXi'an 710071People's Republic of China

In this paper, a novel solution mitigating the radio blackout problem is proposed, which improves existing traveling magnetic field(TMF)-based methods. The most significant advance lies in replacing the external injection with self-induced current, which does not require electrodes. The improved analytical model is derived to evaluate the electron density reduction taking into consideration the self-induced current for various TMF velocities. The plasma reduction performance is analyzed for several conditions including the total absence of injected current. The results show that the velocity may be used to trade off the injected current and, when sufficiently large, eliminates the need for an injected current while mitigating radio blackout. The effectiveness of this solution to the blackout problem is demonstrated in commonly used aerospace communication bands. With a field strength of less than 0.15 T, increasing the velocity from40 m s^-1 to 3100 m s^-1 is all that is required to obviate the need for an injected current. Moreover,typical reduction ratios for electronic density tolerance(2, 1.9, 1.75 and 3 times for the L-, S-, Cand X-bands, respectively, at an altitude of 40 km) remain unchanged. Increasing the velocity of the TMF is much easier than injecting current via a metal electrode into a high-temperature flow field. The TMF method appears practical in regard to possible future applications.

关键词： blackout traveling magnetic field self-induced current traveling magnetic field velocity

A strong robustness open-circuit fault diagnosis strategy for novel fault-tolerant electric drive system based on d-q-axis current signal

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Chinese Journal of Aeronautics 2021年第10期34卷 115-127页

作者： Xuefeng JIANG shaoshuai WANG Jie LI Daoyu WU Wenxin HUANG Zhenmao HAN School of Automation Nanjing University of Science and TechnologyNanjing 210094China College of Automation Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China Aviation Key Laboratory of Science and Technology on Aero Electromechanical System Integration Nanjing 211106China

To diagnose the Open-Circuit(OC)fault in the novel fault-tolerant electric drive system,based on d-q-axis current signal,a strong robustness diagnosis strategy is proposed and *** independent power supplies and converters are required in the novel fault-tolerant electric drive system based on Dual-Winding Permanent Magnet Motor(DWPMM),and the system’s reliability,usage ratio and power density have been improved compared to the conventional fault-tolerant motor drive ***,the novel fault-tolerant electric drive system has the OC fault diagnostic false alarms issue when load changes suddenly or under light-load *** it lacks the research on the diagnostic method when the system encounters intermittent OC fault in power *** theory derivation,simulation and experimental verification,it can be concluded that the proposed strong robustness OC fault diagnosis strategy based on d-q-axis current signal can overcome the OC fault diagnostic false alarms issue when load changes suddenly or under light-load *** it can detect and locate the OC fault of single-phase winding in real time,and diagnose the intermittent OC fault of power switches.

关键词： Dual-winding motor Electric drive system Fault-tolerant system Open-circuit fault diagnosis Permanent magnet motor Strong robustness

Hybrid model for BOF oxygen blowing time prediction based on oxygen balance mechanism and deep neural network

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International Journal of Minerals,Metallurgy and Materials 2024年第1期31卷 106-117页

作者： Xin Shao Qing Liu Zicheng Xin Jiangshan Zhang Tao Zhou shaoshuai Li State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China Engineering Research Center of MES Technology for Iron&Steel Production Ministry of EducationBeijing 100083China Laiwu Iron and Steel Group Yinshan Section Steel Co. Ltd.Jinan 271104China

The amount of oxygen blown into the converter is one of the key parameters for the control of the converter blowing process,which directly affects the tap-to-tap time of converter. In this study, a hybrid model based on oxygen balance mechanism (OBM) and deep neural network (DNN) was established for predicting oxygen blowing time in converter. A three-step method was utilized in the hybrid model. First, the oxygen consumption volume was predicted by the OBM model and DNN model, respectively. Second, a more accurate oxygen consumption volume was obtained by integrating the OBM model and DNN model. Finally, the converter oxygen blowing time was calculated according to the oxygen consumption volume and the oxygen supply intensity of each heat. The proposed hybrid model was verified using the actual data collected from an integrated steel plant in China, and compared with multiple linear regression model, OBM model, and neural network model including extreme learning machine, back propagation neural network, and DNN. The test results indicate that the hybrid model with a network structure of 3 hidden layer layers, 32-16-8 neurons per hidden layer, and 0.1 learning rate has the best prediction accuracy and stronger generalization ability compared with other models. The predicted hit ratio of oxygen consumption volume within the error±300 m^(3)is 96.67%;determination coefficient (R^(2)) and root mean square error (RMSE) are0.6984 and 150.03 m^(3), respectively. The oxygen blow time prediction hit ratio within the error±0.6 min is 89.50%;R2and RMSE are0.9486 and 0.3592 min, respectively. As a result, the proposed model can effectively predict the oxygen consumption volume and oxygen blowing time in the converter.

关键词： basic oxygen furnace oxygen consumption oxygen blowing time oxygen balance mechanism deep neural network hybrid model