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Strong shock propagation for the finite-source circular blast in a confined domain

Applied Mathematics and Mechanics(English Edition) 2024年第6期45卷 1071-1084页

作者： Qihang MA Kaileong CHONG Bofu WANG Quan ZHOU Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai Institute of Applied Mathematics and MechanicsSchool of Mechanics and Engineering ScienceShanghai UniversityShanghai 200072China Shanghai Institute of Aircraft Mechanics and Control Shanghai 200092China

The circular explosion wave produced by the abrupt discharge of gas from a high-temperature heat source serves as a crucial model for addressing explosion phenomena in compressible *** reflection of the primary shock and its propagation within a confined domain are studied both theoretically and numerically in this *** the assumption of strong shock,the scaling law governing propagation of the main shock is *** dimensionless frequency of reflected shock propagation is associated with the confined *** numerical simulation for the circular explosion problem in a confined domain is performed for *** the influence of confinement,the principal shock wave systematically undergoes reflection within the domain until it weakens,leading to the non-monotonic attenuation of kinetic energy in the explosion fireball and periodic oscillations of the fireball volume with a certain *** simulation results indicate that the frequency of kinetic energy attenuation and the volume oscillation of the explosive fireball align consistently with the scaling law.

关键词： explosion confinement main shock frequency

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Energy Efficient Dual User Association for Large Scale IRS-Aided mmWave Communication Networks

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China Communications 2025年第1期22卷 182-195页

作者： Chen Guolin Deng Yiqin Huang Xiaoxia Fang Yuguang School of Electronics and Communication Engineering Sun Yat-sen UniversityShenzhen 518107China School of Control Science and Engineering Shandong UniversityJinan 250100China Department of Computer Science City University of Hong KongHong Kong 999077China

The deployment of multiple intelligent reflecting surfaces(IRSs)in blockage-prone millimeter wave(mmWave)communication networks have garnered considerable attention *** the remarkably low circuit power consumption per IRS element,the aggregate energy consumption becomes substantial if all elements of an IRS are turned on given a considerable number of IRSs,resulting in lower overall energy efficiency(EE).To tackle this challenge,we propose a flexible and efficient approach that individually controls the status of each IRS ***,the network EE is maximized by jointly optimizing the associations of base stations(BSs)and user equipments(UEs),transmit beamforming,phase shifts of IRS elements,and the associations of individual IRS elements and *** problem is efficiently addressed in two ***,the Gale-Shapley algorithm is applied for BS-UE association,followed by a block coordinate descent-based algorithm that iteratively solves the subproblems related to active beamforming,phase shifts,and element-UE *** reduce the tremendous dimensionality of optimization variables introduced by element-UE associations in large-scale IRS networks,we introduce an efficient algorithm to solve the associations between IRS elements and *** results show that the proposed elementwise control scheme improves EE by 34.24% compared to the network with IRS-all-on scheme.

关键词： energy efficiency intelligent reflecting surface,millimeter-wave communication

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Lightning trip prediction of overhead transmission lines based on CNN-GRU network 9

Lightning trip prediction of overhead transmission lines bas...

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9th International Symposium on Sensors, Mechatronics, and Automation System, ISSMAS 2023

作者： Wang, Sifan Wu, Weili School of Electrical and Control Engineering Xi'an University of Science and Technology Xi'an710054 China

ISBN: (纸本)9781510672802

Aiming at the high randomness and uncertainty of lightning trips in overhead transmission lines, the prediction accuracy and efficiency of lightning trips are low, and a prediction method of the lightning trip for overhead transmission lines based on CNN-GRU is proposed. Firstly, the feature set of lightning trip prediction influencing factors of overhead transmission lines is constructed based on the main characteristics influencing factors of overhead transmission lines and operating environment characteristics influencing factors. Secondly, the association rules are used to quantify the correlation between influencing factors and lightning trips. Finally, the Convolutional Neural Network (CNN) -gated Recurrent Unit (GRU) combined network is used to extract the high-dimensional internal connections between the influencing feature factors and line lightning tripping and train them. Combined with practical examples, the prediction results show that the CNN-URU prediction model proposed in this paper has higher prediction accuracy and efficiency than other prediction models. © 2024 SPIE.

关键词： Convolutional neural network Gate control unit Influencing factors Lightning trip Overhead transmission line

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Exponential Synchronization for Mobile Robotic Formation: A Hybrid Dynamic Event-Triggered Intermittent control Method

IEEE Transactions on Intelligent Vehicles

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IEEE Transactions on Intelligent Vehicles 2024年 1-10页

作者： Chang, Zhenyu Guo, Ying Zong, Guangdeng Qi, Wenhai Zhao, Xudong School of Control Science and Engineering Tiangong University Tianjin China School of Computer Science Beijing University of Posts and Telecommunications Beijing China School of Engineering Qufu Normal University Rizhao China Faculty of Electronic Information and Electrical Engineering Dalian University of Technology Dalian China

To address the formation tracking issue of mobile robotic systems, this paper constructs a novel hybrid dynamic event-triggered intermittent control strategy, which can achieve the exponential synchronization of the systems. Considering the limited control resources, the intermittent control method is introduced into the distributed control strategy to save resources, and the existing intermittent control model is reconstructed to describe the system model better. A hybrid dynamic event-triggered mechanism is developed by combining the dynamic event-triggered method with the time sampling strategy, eliminating the Zeno phenomenon. The control time sequences in the developed intermittent control strategy are automatically selected by the hybrid dynamic event-triggered sequences, rather than artificially designed in advance, which reduces a certain degree of design complexity. The developed control strategy effectively saves control resources while alleviating the burden of network communication. Sufficient conditions for achieving exponential synchronization formation tracking are provided, and the exponential convergence of the formation error is demonstrated through the proposed lemma. Finally, a control task of multi-mobile robots formation is presented to verify the effectiveness of the theoretical analysis. IEEE

关键词： Synchronization

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Advanced synaptic devices and their applications in biomimetic sensory neural system

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Chip 2023年第1期2卷 1-22页

作者： Yiqi Sun Jiean Li Sheng Li Yongchang Jiang Enze Wan Jiahan Zhang Yi Shi Lijia Pan School of Electronic Science and Engineering Nanjing University210093NanjingChina School of Microelectronics and Control Engineering Changzhou University213164ChangzhouChina School of Computer Sci-ence and Engineering Macao University of Science and Technology

Human nervous system,which is composed of neuron and synapse networks,is capable of processing information in a plastic,dataparallel,fault-tolerant,and energy-efficient *** by the ingenious working mechanism of this miraculous biological data processing system,scientists have been devoting great efforts to ar-tificial neural systems based on synaptic devices in recent *** continuous development of bioinspired sensors and synaptic devices in recent years have made it possible that artificial sensory neural systems are capable of capturing and processing stimuli informa-tion in real *** progress of biomimetic sensory neural systems could provide new methods for next-generation humanoid robotics,human-machine interfaces,and other frontier ***,this review summarized the recent progress of synaptic devices and biomimetic sensory neural ***,the opportunities and remaining challenges in the further development of biomimetic sensory neural systems were also outlined.

关键词： Artificial synapse Biomimetic sensory neural system Memristor Synaptic transistor

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Photodegradation of xylene isomers:Kinetics,mechanism,secondary pollutant formation potential and health risk evaluation

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Journal of Environmental sciences 2024年第2期136卷 658-669页

作者： Xiaoyan Chen Weikun Zhu Sufen Feng Jiangyao Chen Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control Guangdong Technology Research Center for Photocatalytic Technology Integration and Equipment EngineeringInstitute of Environmental Health and Pollution ControlGuangdong University of TechnologyGuangzhou 510006China Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and HealthSchool of Environmental Science and EngineeringGuangdong University of TechnologyGuangzhou 510006China

Photodegradation technology has been widely applied in the purification of industrial aromatic ***,whether this technology efficiently removes the pollutants to prevent secondary pollution and health risk is still ***,the photodegradation processes of three xylenes were compared under designed reaction atmospheres and light *** lamp showed poor photodegradation ability toward xylenes,no matter in N_(2) or N_(2)+O_(2)system,while much higher photodegradation performance of xylenes were obtained under ultraviolet(UV)and vacuum ultraviolet(VUV)irradiation,especially in N_(2)+O_(2)+VUV system,where 97.9%of m-xylene,99.0%of o-xylene or 87.5%of p-xylene with the initial concentration of 860 mg/m^(3) was removed within 240 *** xylenes underwent three processes of photo-isomerization,photodecomposition and photo-oxidation to produce intermediates of aromatics,alkanes and *** them,the photo-isomerization products showed the highest concentration percentage(e.g.,≥50%in o-xylene system),confirming that photo-isomerization reaction was the dominated photodegradation process of ***,these isomerized products not only contributed about 97%and91%to the formation potential of O3(OFP)and secondary organic aerosols(SOAFP),but also displayed obvious non-carcinogenic risk,although one of photodecomposition product—benzene showed the highest occupational exposure ***,the secondary pollution and health risks of photodegradation products of xylenes were non-ignorable,although the OFP,SOAFP and health risks of the generated products reduced at least 4.5 times in comparison with that of the degraded *** findings are helpful for the appropriate application of this technology in the purification of industrial organic waste gas.

关键词： Isomer aromatics Photodegradation Ozone formation Secondary organic aerosols Health risk

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Sensorless control of Permanent Magnet Synchronous Motor Based on Improved SMO 18th

Sensorless Control of Permanent Magnet Synchronous Motor Bas...

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18th Annual Conference of China Electrotechnical Society, ACCES 2023

作者： Li, Yingchun Li, Qiao Yang, Sen School of Electrical and Control Engineering Shaanxi University of Science and Technology Xi’an710021 China

ISBN: (纸本)9789819713509

Aiming at the vector control of permanent magnet synchronous motor (PMSM), a position sensorless control strategy with improved sliding mode observer (SMO) is proposed by taking advantage of the advantages of SMO, such as insensitivity to motor parameters and disturbances, fast response speed and strong robustness. In order to improve the error caused by high-frequency chattering in estimating rotor speed and rotor position of traditional SMO, the symbol function is replaced by a new saturation function to reduce the chattering with high frequency in the system;Meanwhile, the phase locked loop (PLL) is used to replace the inverse tangent function for rotor position estimation, and adopt the improved PLL, the traditional PI is replaced by the fraction-order PI, later, Lyapunov stability criterion was used to prove the stability of the improved SMO. Finally, an improved SMO positionless sensor control strategy model based on PMSM was built through MATLAB/Simulink for simulation analysis, and the program code was configured through the built model and the motor was used for experimental verification. © Beijing Paike Culture Commu. Co., Ltd. 2024.

关键词： Sensorless control

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Visual Reinforcement Learning Using Dynamic State Representation for Continuous Motion control 43

Visual Reinforcement Learning Using Dynamic State Representa...

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43rd Chinese control Conference, CCC 2024

作者： Tang, Zhan-Yun Liu, Ya-Rong Qin, Pan Dalian University of Technology School of Control Science and Engineering Liaoning Dalian116014 China

ISBN: (纸本)9789887581581

Visual reinforcement learning (VRL) realizes policy learning based on video recordings of agent-environment interaction processes. However, due to the diversity and uncertainty of pixel information, VRL suffers from low sample efficiency in control tasks. The key challenge lies in finding effective state representation methods to provide effective data samples for policy learning. In this paper, we propose a method for dynamically modeling the state of VRL used for motion control tasks. We first analyze the insufficiency of traditional visual state reconstruction and VRL methods. Then, we introduce a new method that incorporates the four-dimensional spatiotemporal data encoding by 3D convolutional layers for dynamic state representation. Finally, we demonstrate the effectiveness of our proposed method on four representative continuous motion control tasks. Our method effectively enhances the expression of visual states and improves sample efficiency of VRL for continuous motion control. © 2024 Technical Committee on control Theory, Chinese Association of Automation.

关键词： Reinforcement learning

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A Real-Time Waste Segregation Using Machine Vision for Recycling Facilities 7

A Real-Time Waste Segregation Using Machine Vision for Recyc...

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7th IEEE International Electrical and Energy Conference, CIEEC 2024

作者： Qaisar, Muhammad Waqas Fang, Jingyang Masood, Umar School of Control Science and Engineering Shandong University Jinan China School of Electrical Engineering Namal University Mianwali Pakistan

ISBN: (纸本)9798350359558

Recycling facilities are often challenged by the demanding task of waste segregation, a process traditionally requiring substantial time and manpower, and lacking efficient automated solutions. Addressing this, our study explores the use of convolutional neural networks (CNNs), particularly the ResNet-18 model, known for its balance of accuracy and computational efficiency compared to its deeper counterparts like ResNet-50 or ResNet-101. ResNet-18 provides sufficient complexity for precise image classification while enabling faster processing speeds essential for real-time applications. Our method employs this CNN to effectively categorize waste into five distinct types, streamlining the sorting process. In this paper, we introduce a custom-designed hardware system, incorporating motor control for the physical segregation of waste. This system operates in tandem with the ResNet-18's classification results, ensuring that each type of waste is accurately sorted into designated bins. Our integrated approach, which pairs the image classification capabilities of ResNet-18 with a practical hardware automation system, aims to improve the efficiency and accuracy of waste segregation in recycling facilities. © 2024 IEEE.

关键词： Convolution

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Attention-Equal-Mixed Sampling Shapley Counterfactual Credit Assignment for Multi-agent Reinforcement Learning 7th

Attention-Equal-Mixed Sampling Shapley Counterfactual Credit...

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7th Chinese Conference on Swarm Intelligence and Cooperative control, CCSICC 2023

作者： Xu, Jinhui Wang, Dong Xu, Xiaopeng Tian, Peng School of Control Science and Engineering Dalian University of Technology Liaoning Dalian116000 China

ISBN: (纸本)9789819733354

Credit assignment, allocating the expectation of the discounted accumulation of the global rewards based on each agent’s contribution, is one of main challenges of the multi-agent reinforcement learning. In this paper, we use Shapley Value, a classical theory in cooperative games, to assign credits. Firstly, we define a weighted Shapley value considering relationships between participants. To reduce computational complexity when ensuring accuracy, we approximate it by a Monte Carlo method based on designed attention-equal-mixed sampling. Secondly, based on the framework with a central critic and decentralized actors, we develop a credit assignment algorithm, in which actor attention networks provide attention scores to sample subsets, then the central critic uses them to estimate Shapley values counterfactually. To verify the efficacy of the algorithm, ablation experiments have been conducted on the StarCraft Multi-Agent Challenge (SMAC). The results indicate that the counterfactual way and the sampling method are effective. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024.

关键词： Monte Carlo methods

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