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design of double protograph LDPC codes based JSCC systems via the ACE-PEG algorithm

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Science China(Information Sciences) 2024年第7期67卷 339-340页

作者： Yijie LV Jiguang HE Shaohua HONG Department of Information and communication Engineering Xiamen University Technology Innovation institute Centre for Wireless communications Oulu University

In this study, we present a state-of-the-art design of double protograph low-density parity-check (DP-LDPC) codes based on progressive edge-growth (PEG) algorithm with approximated cycle extrinsic message degree (ACE)... 详细信息

关键词： Benchmarking

Two-layer Lagrange-based relay network topology and trajectory design for solar system explorations

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Science China(Information Sciences) 2024年第6期67卷 342-358页

作者： Jun CAO Jian JIAO Hao LIU Rongxing LU Qinyu ZHANG Guangdong Provincial Key Laboratory of Aerospace communication and Networking Technology Harbin Institute of Technology (Shenzhen) Faculty of Computer Science (FCS) University of New Brunswick

Exploration targeting outer planets and even the edge of the solar system is an emerging direction for the deep-space exploration in the next decades. To address this challenge, a novel two-layer Lagrangebased relay network topology is proposed in this study. Specifically, we utilize the Sun-Mars and Sun-Saturn Lagrange points(LPs) L4 and L5 to build a two-layer backbone relay network, which ensures continuous and high-efficiency communication capability for the exploration of the solar system. Furthermore, we utilize the planetary gravity assist and design the transfer trajectory of backbone relays with the help of planetary celestial body motion equations and Kepler's laws. Moreover, we conduct link budget analysis for multihop relay transmission under Gamma-Gamma distribution, shadowed Rician fading, and additive white Gaussian noise channels in several typical exploration scenarios and validate that the LP relays can effectively support future deep-space exploration missions.

关键词： deep-space communication Lagrangian points backbone relay network transfer trajectory relay selection

A Li_(3)P nanoparticle dispersion strengthened ultrathin Li metal electrode for high energy density rechargeable batteries

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Nano Research 2024年第5期17卷 4031-4038页

作者： Lin Fu Xiancheng Wang Bao Zhang Zihe Chen Yuanjian Li Yongming Sun Provincial guizhou Key Laboratory of Green Chemical and Clean Energy Technology School of Chemistry and Chemical EngineeringGuizhou UniversityGuiyang 550025China Wuhan National Laboratory for Optoelectronics Huazhong University of Science and TechnologyWuhan 430074China School of Physical and Mathematical Sciences Nanyang Technological UniversitySingapore 637371Singapore institute of Materials Research and Engineering Agency for Science Technology and Research(A*STAR)Singapore 138634Singapore

Achievement of lithium(Li)metal anode with thin thickness(e.g.,≤30µm)is highly desirable for rechargeable high energy density ***,the fabrication and application of such thin Li metal foil electrode remain challenging due to the poor mechanical processibility and inferior electrochemical performance of metallic ***,mechanico-chemical synthesis of robust ultrathin Li/Li_(3)P(LLP)composite foils(~15µm)is demonstrated by employing repeated mechanical rolling/stacking operations using red P and metallic Li as raw *** in-situ formed Li+-conductive Li_(3)P nanoparticles in metallic Li matrix and their tight bonding strengthen the mechanical durability and enable the successful fabrication of free-standing ultrathin Li metal composite ***,it also reduces the electrochemical Li nucleation barrier and homogenizes Li plating/stripping *** matching to high-voltage LiCoO_(2),the full cell with a low negative/positive(N/P)capacity ratio of~1.5 offers a high energy density of~522 W·h·kg^(-1) at 0.5 C based on the mass of cathode and *** into account its facile manufacturing,potentially low cost,and good electrochemical performance,we believe that such an ultrathin composite Li metal foil design with nanoparticle-dispersion-strengthened mechanism may boost the development of high energy density Li metal batteries.

关键词： lithium metal anode high energy density battery mechanico-chemical synthesis ultrathin Li/Li_(3)P composite foil low negative/positive capacity ratio

Artificial-intelligent-powered safety and efficiency improvement for controlling and scheduling in integrated railway systems

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High-Speed Railway 2024年第3期2卷 172-179页

作者： Jun Liu Gehui Liu Yu Wang Wanqiu Zhang Beijing National Railway Research&design institute of Signal&communication Group Co.Ltd. Beijing 100070China Engineering Research Center of Railway Industry of Intelligent and Autonomous Train Control Beijing 100070China

The multi-mode integrated railway system,anchored by the high-speed railway,caters to the diverse travel requirements both within and between cities,offering safe,comfortable,punctual,and eco-friendly transportation *** the expansion of the railway networks,enhancing the efficiency and safety of the comprehensive system has become a crucial issue in the advanced development of railway *** light of the prevailing application of artificial intelligence technologies within railway systems,this study leverages large model technology characterized by robust learning capabilities,efficient associative abilities,and linkage analysis to propose an Artificial-intelligent(AI)-powered railway control and dispatching *** system is elaborately designed with four core functions,including global optimum unattended dispatching,synergetic transportation in multiple modes,high-speed automatic control,and precise maintenance decision and *** deployment pathway and essential tasks of the system are further delineated,alongside the challenges and obstacles *** AI-powered system promises a significant enhancement in the operational efficiency and safety of the composite railway system,ensuring a more effective alignment between transportation services and passenger demands.

关键词： High-speed railway Multi-mode railway system Artificial intelligence Large-scale mode,system framework Safety and efficiency improvement

SAR regional all-azimuth observation orbit design for target 3D reconstruction

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Journal of Systems Engineering and Electronics 2024年第3期35卷 609-618页

作者： WANG Yanan ZHOU Chaowei LIU Aifang MAO Qin Beijing institute of Tracking and communication Technology Beijing 100094China Nanjing Research institute of Electronics Technology Nanjing 210012China Shanghai Aerospace Electronic Technology institute Shanghai 201109China

Three-dimensional(3D) synthetic aperture radar(SAR)extends the conventional 2D images into 3D features by several acquisitions in different aspects. Compared with 3D techniques via multiple observations in elevation, e.g. SAR interferometry(InSAR) and SAR tomography(TomoSAR), holographic SAR can retrieve 3D structure by observations in azimuth. This paper focuses on designing a novel type of orbit to achieve SAR regional all-azimuth observation(AAO) for embedded targets detection and holographic 3D reconstruction. The ground tracks of the AAO orbit separate the earth surface into grids. Target in these grids can be accessed with an azimuth angle span of360°, which is similar to the flight path of airborne circular SAR(CSAR). Inspired from the successive coverage orbits of optical sensors, several optimizations are made in the proposed method to ensure favorable grazing angles, the performance of 3D reconstruction, and long-term supervision for SAR sensors. Simulation experiments show the regional AAO can be completed within five hours. In addition, a second AAO of the same area can be duplicated in two days. Finally, an airborne SAR data process result is presented to illustrate the significance of AAO in 3D reconstruction.

关键词： synthetic aperture radar(SAR) orbit design all-azimuth observation(AAO) three-dimensional(3D)reconstruction successive coverage

Exploring formation mechanism and source attribution of ozone during the 2019 Wuhan Military World Games:Implications for ozone control strategies

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Journal of Environmental Sciences 2024年第2期136卷 400-411页

作者： Lei Zhang Lili Wang Runyu Wang Nan Chen Yuan Yang Ke Li Jie Sun Dan Yao Yuesi Wang Minghui Tao Yang Sun institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029China University of the Chinese Academy of Sciences Beijing 100049China Hubei Ecological Environment Monitoring Center Station Wuhan 430072China guizhou Research and designing institute of Environmental Sciences Guizhou Academy of Environmental Science and DesignGuiyang 550081China Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment TechnologySchool of Environmental Science and EngineeringNanjing University of Information Science and TechnologyNanjing 210044China School of Environment Key Laboratory for Yellow River and Huai River Water Environment and Pollution ControlMinistry of EducationHenan Normal UniversityXinxiang 453007China Key Laboratory of Regional Ecology and Environmental Change School of Geography and Information EngineeringChina University of GeosciencesWuhan 430074China

A series of emission reduction measures were conducted in Wuhan,Central China,to ensure good air quality during the 7th Military World Games(MWG)in October *** better understand the implications for ozone(O_(3))pollution control strategies,we applied integrated analysis approaches based on the de-weathered statistical model,parameterization methods,chemical box model,and positive matrix factorization *** the MWG,concentrations of O_(3),NO_x,and volatile organic compound(VOCs),OFP(O_(3)formation potential),L_(OH)(OH radical loss rate)were 83μg/m^(3),43μg/m^(3),26 ppbv,188μg/m^(3),and 3.9 s^(-1),respectively,which were 26%,18%,3%,15%,and 13%lower than pre-MWG values and 6%,39%,30%,33%,and 50%lower than post-MWG values,*** removing meteorological influence,O_(3)and its precursors during the MWG decreased largely compared with post-MWG values,and only O_(3),NO_(2),and oxygenated VOCs(OVOCs)declined compared with pre-MWG values,which revealed the emission reduction measures during the MWG played an important role for O_(3)*** six VOCs sources,the mass contributions of biomass burning and solvents usage during the MWG decreased largely compared with pre-MWG values.O_(3)production was sensitive to VOCs and the key species were aromatics,OVOCs,and alkenes,which originated mainly from solvents usage,biomass burning,industrial-related combustion,and vehicle *** O_(3)concentration during the strict control was mainly caused by OVOCs reduction due to biomass burning ***,the O_(3)abatement strategies of Wuhan should be focused on the mitigation of high-reactivity VOCs.

关键词： VOCs Ozone Wuhan Military World Games Source apportionment Relative incremental reactivity Random forest

Wireless Positioning:Technologies,Applications,Challenges,and Future Development Trends

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Computer Modeling in Engineering & Sciences 2024年第5期139卷 1135-1166页

作者： Xingwang Li Hua Pang Geng Li Junjie Jiang Hui Zhang Changfei Gu Dong Yuan School of Physics and Electronic Information Engineering University of Henan PolytechnicJiaozuo454000China Jiaozuo Key Laboratory of Crow-Sensing Network Jiaozuo454000China institute of Mining Engineering Guizhou Institute of TechnologyGuiyang550003China Coal Supervision Department Panzhou Energy BureauPanzhou553599China

The development of the fifth-generation(5G)mobile communication systems has entered the commercialization stage.5G has a high data rate,low latency,and high reliability that can meet the basic demands of most industries and daily life,such as the Internet of Things(IoT),intelligent transportation systems,positioning,and *** continuous progress and development of society have aroused wide *** accuracy is the core demand for the applications,especially in complex environments such as airports,warehouses,supermarkets,and ***,many factors also affect the accuracy of positioning in those environments,for example,multipath effects,non-line-of-sight,and clock synchronization *** paper provides a comprehensive review of the existing works about positioning for the future wireless network and discusses its key techniques and algorithms,as well as the current development and future *** first outline the current traditional positioning technologies and algorithms,which are discussed and analyzed with the relevant *** addition,we also discuss application scenarios for wireless *** comparing different positioning systems,the challenges and future development directions of existing wireless positioning systems are prospected.

关键词： 5G wireless positioning reconfigurable intelligent surface Internet of Vehicles

Urban Landscaping design and Carbon Reduction Planning Countermeasures

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Journal of Landscape Research 2024年第3期16卷 11-14页

作者： AN Shaoyuan School of Karst Science Guizhou Normal UniversityGuiyangGuizhou 550001China State Engineering Technology institute for Karst Desertification Control GuiyangGuizhou 550001China guizhou Engineering Laboratory for Karst Rocky Desertification Control and Derivative Industry GuiyangGuizhou 550001China

As the most significant green ecological resource in densely populated and economically developed areas,urban landscaping plays a pivotal role in carbon sink value and multiple ecosystem service *** is a crucial element in the advancement of green and low-carbon initiatives in China’s major cities and the realization of a carbon-neutral *** analyzing the relationship between carbon emission reduction and urban landscaping,the paper sorts out and summarizes the basic principles of urban landscaping design,proposes the role of landscape design in urban landscaping,and plans countermeasures for carbon reduction in urban landscaping,with a view to optimizing the construction and management of urban landscaping.

关键词： Landscape architecture Climate change Carbon neutral Carbon source sink Carbon reduction strategy

design Framework of Unsourced Multiple Access for 6G Massive IoT

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China communications 2024年第1期21卷 1-12页

作者： Chunlin Yan Siying Lyu Sen Wang Yuhong Huang Xiaodong Xu China Mobile communication Research institute Beijing 100053China ZGC institute of Ubiquitous-X Innovation and Applications Beijing 100080China State Key Laboratory of Networking and Switching Technology Beijing University of Posts and TelecommunicationsBeijing 100876China

In this paper,ambient IoT is used as a typical use case of massive connections for the sixth generation(6G)mobile communications where we derive the performance requirements to facilitate the evaluation of technical solutions.A rather complete design of unsourced multiple access is proposed in which two key parts:a compressed sensing module for active user detection,and a sparse interleaver-division multiple access(SIDMA)module are simulated side by side on a same platform at balanced signal to noise ratio(SNR)operating *** a proper combination of compressed sensing matrix,a convolutional encoder,receiver algorithms,the simulated performance results appear superior to the state-of-the-art benchmark,yet with relatively less complicated processing.

关键词： channel coding compressed sensing massive Internet-of-Things(IoT) sparse interleaverdivision multiple access(SIDMA) the sixth generation(6G)mobile communications unsourced multiple access