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Robust cooperative multi-agent reinforcement learning via multi-view message certification

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Science China(Information Sciences) 2024年第4期67卷 131-145页

作者： lei yuan Tao JIANG Lihe LI Feng CHEN Zongzhang ZHANG Yang YU National Key Laboratory for Novel Software Technology Nanjing University Polixir Technologies

Many multi-agent scenarios require message sharing among agents to promote coordination,hastening the robustness of multi-agent communication when policies are deployed in a message perturbation environment. Major relevant studies tackle this issue under specific assumptions, like a limited number of message channels would sustain perturbations, limiting the efficiency in complex scenarios. In this paper,we take a further step in addressing this issue by learning a robust cooperative multi-agent reinforcement learning via multi-view message certification, dubbed CroMAC. Agents trained under CroMAC can obtain guaranteed lower bounds on state-action values to identify and choose the optimal action under a worst-case deviation when the received messages are perturbed. Concretely, we first model multi-agent communication as a multi-view problem, where every message stands for a view of the state. Then we extract a certificated joint message representation by a multi-view variational autoencoder(MVAE) that uses a product-of-experts inference network. For the optimization phase, we do perturbations in the latent space of the state for a certificate guarantee. Then the learned joint message representation is used to approximate the certificated state representation during training. Extensive experiments in several cooperative multi-agent benchmarks validate the effectiveness of the proposed CroMAC.

关键词： multi-agent reinforcement learning robust communication adversarial training multi-view learning message certification

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Revolutionary technology of low-carbon chemical processes

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National Science Review 2023年第9期10卷 15-17页

作者： Suojiang Zhang Xiangping Zhang Chunyan Shi Ke Wang lei yuan Institute of Process Engineering Chinese Academy of Sciences Longzihu New Energy Laboratory Zhengzhou Institute of Emerging Industrial Technology 3. College of Energy Science and Technology Henan University

The chemical industry is one of the key sectors in *** chemical processes heavily rely on fossil fuels as energy resources and feedstocks,which inevitably emits a huge amount of *** the global initiative and actions of carbon neutrality,the energy revolution of renewable energy replacing fossil fuels is further promoted towards the ultimate goal that fossil fuels will be fully replaced in the future [1].

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Effect of La2O3 Addition on Sintering Properties of Magnesia

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China's Refractories 2020年第2期29卷 25-30页

作者： JIN Endong yuan lei YU Jingkun School of Metallurgy Northeastern UniversityShenyang 110819China

Light burned magnesia powders with different particle sizes were obtained by calcining crystalline *** magnesia was prepared from the light burned magnesia powders by adding different amounts of *** effect of the La2O3 addition on the densification of magnesia was *** results show that the densification of sintered magnesia can be promoted both by reducing the particle size of the light burned powder and by adding small amounts of *** effect of the La2O3 addition is more significant:the maximum bulk density of the sintered magnesia can reach 3.49 g·cm-3 and the apparent porosity can be reduced to 0.33%.During sintering,Ca2+from the impurities enters La2O3 lattices,causing lattice distortion of La2O3 thus promoting the formation of La4.67(SiO4)3O phase and CaLa4(SiO4)3O phase,which fill the pores between the MgO grains and promote the densification of sintered magnesia.

关键词： crystalline magnesite sintered magnesia lanthanum oxide bulk density apparent porosity

Hierarchical micro-mobility management in high-speed multihop access networks

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The Journal of China Universities of Posts and Telecommunications 2006年第4期13卷 7-12页

作者： TANG Bi-hua MA Xiao-lei LIU yuan-an GAO Jin-chun School of Electronic Engineering Beijing University of Posts and Telecommunications Beijing 100876 China

This article integrates the hierarchical micro-mobility management and the high-speed multihop access networks （HMAN）, to accomplish the smooth handover between different access reuters. The proposed soft handover scheme in the high-speed HMAN can solve the micro-mobility management problem in the access network. This article also proposes the hybrid access muter （AR） advertisement scheme and AR selection algorithm, which uses the time delay and stable route to the AR as the gateway selection parameters. By simulation, the proposed micro-mobility,management scheme can achieve high packet delivery fraction and improve the lifetime of network.

关键词： Ad-hoc networks hierarchical micro-mobility management wireless multihop access network

Combined simplified maximum likelihood and sphere decoding algorithm for MIMO system

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The Journal of China Universities of Posts and Telecommunications 2008年第2期15卷 56-59,81页

作者： ZHANG lei yuan Ting-ting ZHANG Xin YANG Da-cheng School of Telecommunication Engineering Beijing University of Posts andTeleconununications Beijing 100876 China

In this article, a new system model for sphere decoding （SD） algorithm is introduced. For the 2 × 2 multipleinput multiple-out （MIMO） system, a simplified maximum likelihood （SML） decoding algorithm is proposed based on the new model. The SML algorithm achieves optimal maximum likelihood （ML） performance, and drastically reduces the complexity as compared to the conventional SD algorithm. The improved algorithm is presented by combining the sphere decoding algorithm based on Schnorr-Euchner strategy （SE-SD） with the SML algorithm when the number of transmit antennas exceeds 2. Compared to conventional SD, the proposed algorithm has low complexity especially at low signal to noise ratio （SNR）. It is shown by simulation that the proposed algorithm has performance very close to conventional SD.

关键词： maximum likelihood decoding sphere decoding,MIMO complexity

Experimental Study of Tunnel Fire with Natural Ventilation

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湖南大学学报（自然科学版） 2009年第S1期36卷 23-25页

作者： yuan Zhong-yuan,lei Bo,CHEN Peng-yun(School of Mechanical Engineering,Southwest Jiaotong University,Chengdu,Sichuan 610031,China) School of Mechanical Engineering Southwest Jiaotong University Chengdu 610031 China

The 1/15 reduced-scale experiments using Froude scaling were designed to study the effect on the smoke control efficiency for subway tunnel fires with natural ventilation *** propane gas fires with heat release rate 11.48 kW was used,which corresponds to the heat release rate 10 MW in the full-scale *** temperature distributions under the ceiling were measured by K-type thermocouples to investigate smoke movement,and the velocity of smoke in shafts was measured by hot-wire anemometer to obtain the smoke extract amount of ventilation *** results show that the smoke temperature under the ceiling varies with the longitudinal different distance from fire *** results also show that the smoke temperature distributions and the smoke control efficiency in tunnel vary with the space between ventilation shafts and vary with the area and the height of ventilation shaft.

关键词： natural ventilation mode metro tunnel fire reduced-scale experiments froude scaling

A data assimilation-based forecast model of outer radiation belt electron fluxes

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Earth and Planetary Physics 2023年第6期7卷 620-630页

作者： yuan lei Xing Cao BinBin Ni Song Fu TaoRong Luo XiaoYu Wang Department of Space Physics School of Electronic InformationWuhan UniversityWuhan 430072China Chinese Academy of Sciences Center for Excellence in Comparative Planetology Hefei 230026China

Because radiation belt electrons can pose a potential threat to the safety of satellites orbiting in space,it is of great importance to develop a reliable model that can predict the highly dynamic variations in outer radiation belt electron *** the present study,we develop a forecast model of radiation belt electron fluxes based on the data assimilation method,in terms of Van Allen Probe measurements combined with three-dimensional radiation belt numerical *** forecast model can cover the entire outer radiation belt with a high temporal resolution(1 hour)and a spatial resolution of 0.25 L over a wide range of both electron energy(0.1-5.0 MeV)and pitch angle(5°-90°).On the basis of this model,we forecast hourly electron fluxes for the next 1,2,and 3 days during an intense geomagnetic storm and evaluate the corresponding prediction *** model can reasonably predict the stormtime evolution of radiation belt electrons with high prediction efficiency(up to~0.8-1).The best prediction performance is found for~0.3-3 MeV electrons at L=~3.25-4.5,which extends to higher L and lower energies with increasing pitch *** results demonstrate that the forecast model developed can be a powerful tool to predict the spatiotemporal changes in outer radiation belt electron fluxes,and the model has both scientific significance and practical implications.

关键词： Earth’s outer radiation belt data assimilation electron flux forecast model performance evaluation

Diurnal changes in bacterial communities in oxic surface and hypoxic middle seawater layers of the Changjiang River Estuary

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Acta Oceanologica Sinica 2021年第4期40卷 92-106页

作者： Yan Huang lei yuan Yingping Fan Habib U Rehman Jakhrani Jianxin Wang Marine Microorganism Ecological&Application Laboratory Zhejiang Ocean UniversityZhoushan 316022China

The Changjiang River Estuary(CRE)in the East China Sea suffers from seasonal hypoxia in *** vertical distributions and seasonal changes of microbial communities in the CRE were well ***,little is known about the diurnal changes of bacterial communities in the hypoxic zone of the ***,16 S rRNA gene analysis was used to explore the changes of bacterial communities in the oxic surface and hypoxic middle seawater layers during 24 h in the *** differences between the hypoxic and oxic layers were observed:the phyla Cyanobacteria,Bacteroidetes and Acidimicrobiia were enriched in the oxic layer,whereas the phylum SAR406 and the class Deltaproteobacteria were more abundant in the hypoxic *** addition,some subtle diurnal variations of the bacterial relative abundance were found in both two *** relative abundance of Synechococcus increased at night,and this change was more obvious in the hypoxic *** similar trend was also found in some phototrophic and several heterotrophic bacteria,such as Rhodobacteraceae,OM60 and *** relative abundances peaked at 16:00 in the oxic layer,while the relative abundances peaked at around 7:00 and decreased until 13:00 in the hypoxic ***,the results of the present study suggest that some photosynthetic bacteria and several heterotrophic bacteria have similar diurnal variations implying the light and physicochemical heterogeneity in the course of a day are important for bacterial diurnal changes in the CRE.

关键词： bacterial communities diurnal changes hypoxic zone the Changjiang River Estuary

Mesoscale Simulation for Polymer Migration in Confined Uniform Shear Flow

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Chemical Research in Chinese Universities 2010年第1期26卷 122-127页

作者： HE Yan-dong WANG Yong-lei LU Zhong-yuan LI Ze-sheng State Key Laboratory of Theretical and Computational Chemistry Institute of Theoretical Chemistry Jilin University Changehun 130021P. R. China

The structure and dynamics of confined single polymer chain in a dilute solution, either in equilibrium or at different shear rates in the uniform shear flow fields, were investigated by means of dissipative particle dynamics simulations. The no-slip boundary condition without density fluctuation near the wall was taken into account to mimic the environment of a nanochannel. The dependences of the radius of gyration, especially in three different di- rections, and the density profile of the chain mass center on the strength of the confinement and the Weissenberg number（Wn） was studied. The effect of the interaction between polymer and solvent on the density profile was also investigated in the cases of moderate and strong Wn. In the high shear flow, the polymer migrates to the center of the channel with increasing Wn. There is only one density profile peak in the channel center in the uniform shear flow, which is in agreement with the results of the experiments and theory.

关键词： Confined polymer Dissipative particle dynamics No-slip boundary condition Uniform shear flow