检索结果-南通市图书馆

Data-Sampling Based Controllability Analysis and Optimal Control of Linear Multi-Agent Systems

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2024年

作者： zhao bin School of Science China University of Geosciences Beijing

This paper investigates optimal control for two kinds of multi-agent systems with the sampled-data based communication protocols. Necessary and sufficient conditions on data-sampling controllability are obtained for sampled-data based multi-agent systems, which indicate that sampling periods affect the controllability of double-integrator systems, whereas the controllability of singleintegrator systems is decided by the interconnection topology. To obtain the optimal control inputs under different objectives, two concepts of 2-norm-optimal control and infinity-norm-optimal control are proposed. For both kinds of systems, generalised inverse matrices of controllability test matrices are utilised to derive the 2-norm-optimal controls, and the infinity-norm-optimal controls are equivalently transformed to be the optimal solutions of some specific linear programming problems via matrix vectorization. Some illustrative examples are provided for the main results in this paper.

关键词：

Resource Allocation in Multi-User Cellular Networks:A Transformer-Based Deep Reinforcement Learning Approach

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

China Communications 2024年第5期21卷 77-96页

作者： zhao Di Zheng Zhong Qin Pengfei Qin Hao Song bin State key Laboratory of Integrated Services Networks Xidian University710071China China Academy of Space Technology Beijing 100081China

To meet the communication services with diverse requirements,dynamic resource allocation has shown increasing *** this paper,we consider the multi-slot and multi-user resource allocation(MSMU-RA)in a downlink cellular scenario with the aim of maximizing system spectral efficiency while guaranteeing user *** first model the MSMURA problem as a dual-sequence decision-making process,and then solve it by a novel Transformerbased deep reinforcement learning(TDRL)***,the proposed TDRL approach can be achieved based on two aspects:1)To adapt to the dynamic wireless environment,the proximal policy optimization(PPO)algorithm is used to optimize the multi-slot RA strategy.2)To avoid co-channel interference,the Transformer-based PPO algorithm is presented to obtain the optimal multi-user RA scheme by exploring the mapping between user sequence and resource *** results show that:i)the proposed approach outperforms both the traditional and DRL methods in spectral efficiency and user fairness,ii)the proposed algorithm is superior to DRL approaches in terms of convergence speed and generalization performance.

关键词： dynamic resource allocation multi-user cellular network spectrum efficiency user fairness

Fully Decoupled Branch Energy Balancing Control Method for Modular Multilevel Matrix Converter Based on Sequence Circulating Components

在线全文

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2024年第1期10卷 235-247页

作者： Zexin zhao Weijiang Chen Zhichang Yang Guoliang zhao bin Han Yunfei Xu Nianwen Xiang Shulai Wang China Electric Power Research Institute Beijing 100192China State Grid Corporation of China Beijing 100031China State Grid Smart Grid Research Institute Beijing 102209China State key Laboratory of Advanced Power Transmission Technology Global Energy Interconnection Research InstituteBeijing 102211China Hefei University of Technology Hefei 230009China

The modular multilevel matrix converter(M3C)is a potential frequency converter for low-frequency AC ***,capacitor voltage control of high-voltage and largecapacity M3C is more difficult,especially for voltage balancing between *** solve this problem,this paper defines sequence circulating components and theoretically analyzes the influence mechanism of different sequence circulating components on branch capacitor voltage.A fully decoupled branch energy balancing control method based on four groups of sequence circulating components is *** method can control capacitor voltages of nine branches in horizontal,vertical and diagonal *** influences of both circulating current and voltage,a cross decoupled control is designed to improve control *** results are taken from a low-frequency transmission system based on PSCAD/EMTDC,and effectiveness and precision of the proposed branch energy balancing control method are verified in the case of nonuniform parameters and an unbalanced power system.

关键词： Branch energy balancing control decoupled control low-frequency AC transmission modular multilevel matrix converter(M3C) sequence circulating components

ST-LaneNet: Lane Line Detection Method Based on Swin Transformer and LaneNet

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2024年第1期37卷 130-145页

作者： Yufeng Du Rongyun Zhang Peicheng Shi Linfeng zhao bin Zhang Yaming Liu School of Mechanical Engineering Anhui Polytechnic UniversityWuhu 241000China Automotive New Technology Anhui Engineering and Technology Research Center Anhui Polytechnic UniversityWuhu 241000China School of Automotive and Transportation Engineering Hefei University of TechnologyHefei 230009China

The advancement of autonomous driving heavily relies on the ability to accurate lane lines *** deep learning and computer vision technologies evolve,a variety of deep learning-based methods for lane line detection have been proposed by researchers in the ***,owing to the simple appearance of lane lines and the lack of distinctive features,it is easy for other objects with similar local appearances to interfere with the process of detecting lane *** precision of lane line detection is limited by the unpredictable quantity and diversity of lane *** address the aforementioned challenges,we propose a novel deep learning approach for lane line *** method leverages the Swin Transformer in conjunction with LaneNet(called ST-LaneNet).The experience results showed that the true positive detection rate can reach 97.53%for easy lanes and 96.83%for difficult lanes(such as scenes with severe occlusion and extreme lighting conditions),which can better accomplish the objective of detecting lane *** 1000 detection samples,the average detection accuracy can reach 97.83%,the average inference time per image can reach 17.8 ms,and the average number of frames per second can reach 64.8 *** programming scripts and associated models for this project can be accessed openly at the following GitHub repository:https://***/Duane 711/Lane-line-detec tion-ST-LaneNet.

关键词： Autonomous driving Lane line detection Deep learning Swin transformer

Spectral Selectivity of CdTe Cells with Substrate Configuration for Photovoltaic/Thermal Applications

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2024年第4期33卷 1542-1553页

作者： CHEN ken HU Kongfu zhao bin CHEN Tao HAO Yong PEI Gang Department of Thermal Science and Energy Engineering University of Science and Technology of ChinaHefei230027China key Laboratory of Solar Thermal Conversion of Anhui Province Hefei230027China Hefei National Laboratory for Physical Sciences at Microscale Department of Materials Science and EngineeringUniversity of Science and Technology of ChinaHefei230026China Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing100190China University of Chinese Academy of Sciences Beijing100049China

Existing photovoltaic cells with high infrared emissivity generate huge radiative heat loss in photovoltaic/thermal applications and degrade the photothermal *** purpose of this work is to evaluate the full spectral absorptivity of CdTe cells to find a spectrally selective photovoltaic cell for photovoltaic/thermal *** this end,the solar absorptivity and mid-infrared thermal emissivity of CdTe cells were tested by ellipsometry,UV-Vis-NIR spectrophotometer,and Fourier transform infrared *** experimental results show that the AM 1.5 solar spectrum weighted absorptivity of the substrate configuration CdTe cell reaches 0.91,and the mid-infrared emissivity is only 0.29,while the superstrate configuration cell emissivity is as high as *** research shows that substrate configuration with a transparent conductive layer on top can be flexibly grown on metal foils and has spectral selectivity with high solar absorptivity and low mid-infrared emissivity should be considered in the future for photovoltaic/thermal applications.

关键词： photovoltaic/thermal spectral selectivity substrate configuration CdTe cell ITO

The environment,especially the minimum temperature,affects summer maize grain yield by regulating ear differentiation and grain development

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2024年第7期23卷 2227-2241页

作者： Jing Chen Baizhao Ren bin zhao Peng Liu Jiwang Zhang State key Laboratory of Crop Biology/College of Agronomy Shandong Agricultural UniversityTai’an 271018

Ear differentiation,grain development and their interaction with factors in the growing environment,such as temperature,solar radiation and precipitation,greatly influence grain number and grain weight,and ultimately affect summer maize *** this study,field experiments involving different sowing dates were conducted over three years to evaluate the effects of temperature factors,average solar radiation and total precipitation on the growth process,ear differentiation,fertilization characteristics,grain filling and yield of summer maize varieties with different growth *** hybrids were evaluated in Huang-Huai-Hai Plain(HHHP),China from 2018 to 2020 with five different sowing *** results showed that the grain yield formation of summer maize was strongly impacted by the environment from the silking(R1)to milking(R3)*** minimum temperature(AT_(min))was the key environmental factor that determined *** in the length of the growing season(r=–0.556,P<0.01)and the total floret number on ear(R^(2)=0.200,P<0.001)were found when AT_(min) was elevated from the emerging(VE)to R1 *** grain-filling rate(R^(2)=0.520,P<0.001)and the floret abortion rate on ear(R^(2)=0.437,P<0.001)showed quadratic relationships with AT_(min) from the R1 to physiological maturity(R6)stage,while the number of days after the R1 stage(r=–0.756,P<0.01)was negatively correlated with AT_(min).An increase in AT_(min) was beneficial for the promotion of yield when it did not exceeded a certain level(above 23°C during the R1–R3 stage and 20–21°C during the R1-R6 stage).Enhanced solar radiation and precipitation during R1–R6 increased the grain-filling rate(R^(2)=0.562,P<0.001 and R^(2)=0.229,P<0.05,respectively).Compared with short-season hybrids,full-season hybrids showed much greater suitability for a critical *** coordinated regulation of AT_(min),ear differentiation and grain development at the pre-and post-silking stages improved maize yie

关键词： sowing date hybrid maturity growing environment ear differentiation and grain development

Learning Scalable Task Assignment with Imperative-Priori Conflict Resolution in Multi-UAV Adversarial Swarm Defense Problem

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2024年第1期37卷 369-388页

作者： zhao Zhixin CHEN Jie XIN bin LI Li JIAO keming ZHENG Yifan School of Electronics and Information Engineering Tongji UniversityShanghai 201804China Shanghai Institute of Intelligent Science and Technology Tongji UniversityShanghai 201804China School of Automation Beijing Institute of TechnologyBeijing 100081China National key Laboratory of Autonomous Intelligent Unmanned Systems Beijing 100081China Shanghai Institute of Intelligent Science and Technology Tongji UniversityShanghai 201804China.

The multi-UAV adversary swarm defense(MUASD)problem is to defend a static base against an adversary UAV swarm by a defensive UAV *** the problem into task assignment and low-level interception strategies is a widely used ***-based approaches for task assignment are a promising *** studies on learning-based methods generally assume decentralized decision-making architecture,which is not beneficial for conflict *** contrast,centralized decision-making architecture is beneficial for conflict resolution while it is often detrimental to *** achieve scalability and conflict resolution simultaneously,inspired by a self-attention-based task assignment method for sensor target coverage problem,a scalable centralized assignment method based on self-attention mechanism together with a defender-attacker pairwise observation preprocessing(DAP-SelfAtt)is ***,an imperative-priori conflict resolution(IPCR)mechanism is proposed to achieve conflict-free ***,the IPCR mechanism is parallelized to enable efficient *** validate the algorithm,a variant of proximal policy optimization algorithm(PPO)is employed for training in scenarios of various *** experimental results show that the proposed algorithm not only achieves conflict-free task assignment but also maintains scalability,and significantly improve the success rate of defense.

关键词： Conflict resolution reinforcement learning scalability task assignment.

A modified back analysis method for deep excavation with multi-objective optimization procedure

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2024年第4期16卷 1373-1387页

作者： Chenyang zhao Le Chen Pengpeng Ni Wenjun Xia bin Wang State key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China Guangdong Research Center for Underground Space Exploitation Technology School of Civil EngineeringSun Yat-sen UniversityGuangzhou510275China Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) Zhuhai519000China Jiangsu Provincial Transportation Engineering Construction Bureau Nanjing210004China

Real-time prediction of excavation-induced displacement of retaining pile during the deep excavation process is crucial for construction *** paper proposes a modified back analysis method with multi-objective optimization procedure,which enables a real-time prediction of horizontal displacement of retaining pile during *** opposed to the traditional stage-by-stage back analysis,time series monitoring data till the current excavation stage are utilized to form a multi-objective ***,the multi-objective particle swarm optimization (MOPSO) algorithm is applied for parameter *** optimized model parameters are immediately adopted to predict the excavation-induced pile deformation in the continuous construction *** achieve efficient parameter optimization and real-time prediction of system behavior,the back propagation neural network (BPNN) is established to substitute the finite element model,which is further implemented together with MOPSO for automatic *** proposed approach is applied in the Taihu tunnel excavation project,where the effectiveness of the method is demonstrated via the comparisons with the site monitoring *** method is reliable with a prediction accuracy of more than 90%.Moreover,different optimization algorithms,including non-dominated sorting genetic algorithm (NSGA-II),Pareto Envelope-based Selection Algorithm II (PESA-II) and MOPSO,are compared,and their influences on the prediction accuracy at different excavation stages are *** results show that MOPSO has the best performance for high dimensional optimization task.

关键词： Multi-objective optimization Back analysis Surrogate model Multi-objective particle swarm optimization(MOPSO) Deep excavation

Hydraulic properties and drought response of a tropical bamboo (Cephalostachyum pergracile)

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Plant Diversity 2024年第3期46卷 406-415页

作者： Wanwalee Kongjarat Lu Han Amy Ny Aina Aritsara Shu-bin Zhang Gao-Juan zhao Yong-Jiang Zhang Phisamai Maenpuen Ying-Mei Li Yi-ke Zou Ming-Yi Li Xue-Nan Li Lian-bin Tao Ya-Jun Chen CAS key Laboratory of Tropical Forest Ecology Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesYunnan 666303China University of the Chinese Academy of Sciences Beijing 100049China T-STAR Core Team Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesYunnan 666303China School of Biology and Ecology University of MaineOronoMEUSA Climate Change Institute University of MaineOronoME 04469USA School of Biological and Chemical Science Pu’er UniversityXueyuan RoadYunnan 665000China Institute of Ecology and Geobotany School of Ecology and Environmental SciencesYunnan UniversityKunmingYunnan 650091China School of Ecology and Environment Southwest Forestry UniversityKunmingYunnan 650224China Yuanjiang Savanna Ecosystem Research Station Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesYuanjiangYunnan 653300China

Bamboo plants are an essential component of tropical ecosystems,yet their vulnerability to climate extremes,such as drought,is poorly understood due to limited knowledge of their hydraulic *** pergracile,a commonly used tropical bamboo species,exhibited a substantially higher mortality rate than other co-occurring bamboos during a severe drought event in 2019,but the underlying mechanisms remain *** study investigated the leaf and stem hydraulic traits related to drought responses,including leaf-stem embolism resistance(P50leaf;P50stem) estimated using optical and X-ray microtomography methods,leaf pressure-volume and water-releasing ***,we investigated the seasonal water potentials,native embolism level(PLC) and xylem water source using stable *** found that *** exhibited strong resistance to embolism,showing low P50leaf,P50stem,and turgor loss point,despite its rapid leaf water ***,its leaves displayed greater resistance to embolism than its stem,suggesting a lack of effective hydraulic vulnerability segmentation(HVS) to protect the stem from excessive xylem *** the dry season,approximately 49% of the water was absorbed from the upper 20-cm-deep soil ***,significant diurnal variation in leaf water potentials and an increase in midday PLC from 5.87±2.33% in the wet season to 12.87±4.09%in the dry season were *** summary,this study demonstrated that the rapid leaf water loss,high reliance on surface water,and a lack of effective HVS in *** accelerated water depletion and increased xylem embolism even in the typical dry season,which may explain its high mortality rate during extreme drought events in 2019.

关键词： Climate change Drought Hydraulic safety Hydraulic vulnerability segmentation Stable isotope Tree mortality