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Science China Earth Sciences 2017年第2期60卷 391-396页

作者： LI Jing SUN Lei YU ZhiMing SONG XiuXian Key Laboratory of Marine Ecology and Environmental Sciences Institute of OceanologyChina Academy of Science Laboratory of Marine Ecology and Environmental Science Qingdao National Laboratory for Marine Science and Technology College of Earth Sciences University of Chinese Academy of Sciences College of Environmental Science and Engineering Ocean University of China

Prevention of annual"green tides"caused by blooms of the green macroalga Ulva prolifera,which have occurred in the Yellow Sea since 2007,has received much *** evidence indicates that micro-propagules on the rafts used for Porphyra yezoensis aquaculture along the coastline of Jiangsu Province in China,were the primary source of these green *** this study,we investigated the effectiveness of a silicone antifouling coating for preventing the adhesion and germination of *** micro-propagules on bamboo and nylon ropes,which have been used in rafts for *** *** results demonstrated that a coating of silicone(Sylgard 184)containing 1.0 wt.%sodium benzoate(NaB)could reduce the adhesion rate to<5%and completely inhibited the growth of *** propagules on the coated *** bamboo and nylon ropes with NaB-incorporated silicone thus proved a potentially effective method for controlling the initial biomass accumulation of ***.

关键词： Ulva prolifera Green tide Silicone Sodium benzoate Biofouling

Outage analysis of aerial semi-grant-free NOMA systems

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Digital Communications and Networks 2024年第5期10卷 1529-1541页

作者： Hongjiang Lei Chen Zhu Ki-Hong Park Imran Shafique Ansari Weijia Lei Hong Tang Kyeong Jin Kim School of Communications and Information Engineering Chongqing University of Posts and TelecommunicationsChongqing 400065China Chongqing Key Lab of Mobile Communications Technology Chongqing 400065China CEMSE Division King Abdullah University of Science and Technology(KAUST)Thuwal 23955-6900Saudi Arabia James Watt School of Engineering University of GlasgowGlasgow G128QQUnited Kingdom Samsung Research America(SRA) PlanoTX75023USA

In this paper,we analyze the outage performance of Unmanned Aerial Vehicles(UAVs)-enabled downlink Non-Orthogonal Multiple Access(NOMA)communication systems with the Semi-grant-Free(SGF)transmission scheme.A UAV provides coverage services for a grant-Based(GB)user and one grant-Free(GF)user is allowed to utilize the same channel resource *** analytical expressions for the exact and asymptotic Outage Probability(OP)of the GF user are *** results demonstrate that no-zero diversity order can be achieved only under stringent conditions on users'quality of service ***,an efficient Dynamic Power Allocation(DPA)scheme is proposed to relax such data rate *** analytical expressions for the exact and asymptotic OP of the GF user with the DPA scheme are ***,Monte Carlo simulation results are presented to validate the correctness of the derived analytical expressions and demonstrate the effects of the UAV's location and altitude on the OP of the GF user.

关键词： Unmanned aerial vehicle Non-orthogonal multiple access Semi-grant-free Outage probability

Activity Detection for Enhanced Configured-grant:A Practical Perspective

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China Communications 2022年第3期19卷 181-191页

作者： Chenmin Sha Shidong Zhou Department of Electronic Engineering Tsinghua UniversityBeijing 100084China

We try to extend the current configuredgrant(CG)uplink scheme in 5G New Radio(NR)to support massive potential users and study activity detection under this *** of the continuously varying channel and the multiple repetition scheme are utilized to improve the detection accuracy,which can be an enhancement to existing activity detection *** results under 3 GPP TDL(Tapped Delay Line)fading channel show the superiority of our *** system-level simulation reveals that enhancements on activity detection can improve reliability and reduce latency.

关键词： configured-grant massive access activity detection

grant-Free Random Access in Pilot-Reused Multicell Massive MIMO Systems with Backoff Mechanisms

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China Communications 2023年第9期20卷 185-195页

作者： Qi Zhang Jun Zhang Shi Jin Jiangsu Key Laboratory of Wireless Communications Nanjing University of Posts and TelecommunicationsNanjing 210003China National Mobile Communications Research Laboratory Southeast UniversityNanjing 210096China

grant-free random access(RA)is attractive for future network due to the minimized access *** this paper,we investigate the grantfree RA in multicell massive multiple-input multipleoutput(MIMO)systems with pilot *** backoff mechanism,user equipments(UEs)in each cell are randomly activated,and active UEs randomly select orthogonal pilots from a predefined pilot pool,which results in a random pilot contamination among *** the help of indicators that capture the uncertainties of UE activation and pilot selection,we derive a closed-form approximation of the spectral efficiency per cell after averaging over the channel fading as well as UEs’random *** on the analysis,the optimal backoff parameter and pilot length that maximize the spectral efficiency can be *** find that the backoff mechanism is necessary for the system with large number of UEs,as it can bring significant gains on the spectral ***,as UE number grows,more backoff time is needed.

关键词： backoff mechanism grant-free RA multicell massive MIMO

Evaluating grant proposals:lessons from using metrics as screening device

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Journal of Data and Information Science 2023年第2期8卷 66-92页

作者： Katerina Guba Alexey Zheleznov Elena Chechik Center for Institutional Analysis of Science and Education European University at Saint PetersburgGagarinskaya 6/1A Saint Petersburg 191178Russian Federation

Purpose:This study examines the effects of using publication-based metrics for the initial screening in the application process for a project *** key questions are whether formal policy affects the allocation of funds to researchers with a better publication record and how the previous academic performance of principal investigators is related to future project ***/methodology/approach:We compared two competitions,before and after the policy raised the publication threshold for the principal *** analyzed 9,167 papers published by 332 winners in physics and the social sciences and humanities(SSH),and 11,253 publications resulting from each funded ***:We found that among physicists,even in the first period,grants tended to be allocated to prolific authors publishing in high-quality *** contrast,the SSH project grantees had been less prolific in publishing internationally in both periods;however,in the second period,the selection of grant recipients yielded better results regarding awarding grants to more productive authors in terms of the quantity and quality of *** was no evidence that this better selection of grant recipients resulted in better publication records during grant ***:This study contributes to the discussion of formal policies that rely on metrics for the evaluation of grant *** Russian case shows that such policy may have a profound effect on changing the supply side of applicants,especially in disciplines that are less suitable for metric-based *** spite of the criticism given to metrics,they might be a useful additional instrument in academic systems where professional expertise is corrupted and prevents allocation of funds to prolific researchers.

关键词： grant funding Research evaluation Publication-based metrics Funding allocation

A Joint Activity and Data Detection Scheme for Asynchronous grant-Free Rateless Multiple Access

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China Communications 2024年第1期21卷 34-52页

作者： Wei Zhang Xiaofeng Zhong Shidong Zhou Department of Electronic Engineering Tsinghua UniversityBeijing 100084China

This paper considers the frameasynchronous grant-free rateless multiple access(FAGF-RMA)scenario,where users can initiate access at any symbol time,using shared channel resources to transmit data to the base *** coding is introduced to enhance the reliability of the *** literature has shown that FA-GFRMA can achieve lower access delay than framesynchronous grant-free rateless multiple access(FSGF-RMA),with extreme reliability enabled by rateless *** support FA-GF-RMA in more practical scenarios,a joint activity and data detection(JADD)scheme is *** the feature of sporadic traffic,approximate message passing(AMP)is exploited for transmission signal matrix ***,to determine the packet start points,a maximum posterior probability(MAP)estimation problem is solved based on the recovered transmitted signals,leveraging the intrinsic power pattern in the *** iterative power-pattern-aided AMP algorithm is devised to enhance the estimation performance of *** results verify that the proposed solution achieves a delay performance that is comparable to the performance limit of FA-GF-RMA.

关键词： asynchronous grant-free JADD rateless codes

Achievements and challenges of the World Bank Loan/Department for International Development grant-assisted Tuberculosis Control Project in China

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Chinese Medical Journal 2011年第14期000卷 2216-2218页

作者： KONG Peng JIANG Xu ZHANG Ben JIANG Shi-wen LIU Bo Center for Health Management and Policy Shandong UniversityJinan Shandong 250012 China Department of Foreign Language Shandong Jiaotong UniversityJinan Shandong 250014 China Foreign Loan Office Ministry of Health Beijing 100009 China National Tuberculosis Center Chinese Center for DiseasePrevention and Control Beijing 100050 China

In March 2002,the government of China launched the World Bank Loan/ Department for International Development-supported Tuberculosis （TB） Control Project to reduce the prevalence and mortality of TB. The project generated promising results in policy development, strengthening of TB control systems, patient treatment success,funds management, and the introduction of legislation. In light of the global TB epidemic and control environment, it is useful to review the TB control priorities of the project, summarize the achievements and experiences around its implementation.

关键词： tuberculosis prevention and control directly observed therapy, short-course sustainable development

Pilot Domain NOMA for grant-Free Massive Random Access in Massive MIMO Marine Communication System

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China Communications 2020年第6期17卷 131-144页

作者： Yongxin Liu Ming Zhao Limin Xiao Shidong Zhou Department of Electronic Engineering Tsinghua UniversityBeijing 100084China Tsinghua National Laboratory for Information Science and Technology Tsinghua UniversityBeijing 100084China

We propose a pilot domain non-orthogonal multiple access(NOMA)for uplink massive devices grant-free random access scenarios in massive multiple-input multiple-output(MIMO)maritime communication *** scenarios are characterized by numerous devices with sporadic access behavior,and therefore only a subset of them are *** to massive potential devices in the network,it is infeasible to assign a unique orthogonal pilot to each device in *** such scenarios,pilot decontamination is a crucial *** this paper,the devices are randomly assigned non-orthogonal pilots which are constructed by a linear combination of some orthogonal *** show that a bipartite graph can conveniently describe the interference cancellation(IC)processes of pilot *** spectrum efficiency(SE)and low outage probability can be obtained by selecting the numbers of orthogonal pilots according to the given probability *** evaluatioDs show that the proposed pilot domain NOMA decreases the outage probability from 20%to 2 e-12 at the SE of 4 bits/s/Hz for a single device,compared to the conventional method of slotted ALOHA with 1024 antennas at the BS,or increases the spectrum efficiency from 1.2 bits/s/Hz to 4 bit/s/Hz at the outage probability of2 e-12 in contrast with the Welch bound equality(WBE)non-orthogonal pilots.

关键词： NOMA grant-free random access maritime-communication bipartite graphs density evolution

the 973 Program of China(Nos.2013CB632704 and 2013CB922404);the Knowledge Innovation Program of the Chinese Academy of Sciences(***2-EW-W02);the National Natural Science Foundation of China under grant Nos.11104342 and 61265010.

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Photonics Research 2013年第1期1卷 47-51页

作者： K.D.Leake A.R.Hawkins H.Schmidt School of Engineering University of California Santa Cruz1156 High StreetSanta CruzCalifornia 95064USA Electrical and Computer Engineering Department Brigham Young UniversityProvoUtah 84602USA

We analyze the properties of a dual-beam trap of orthogonally intersecting beams in the geometrical optics *** derive analytical expressions for the trapping location and stability criteria for trapping a microparticle with uncollimated Gaussian *** upper limit for the beam waist is *** forces and particle trajectories are calculated numerically for the realistic case of a microparticle in intersecting liquid-core waveguides.

关键词： trapping beam optics

Active User and Data Detection for Uplink grant-free NOMA Systems

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China Communications 2020年第11期17卷 12-28页

作者： Donghong Cai Jinming Wen Pingzhi Fan Yanqing Xu Lisu Yu 无 The College of Cyber Security Jinan UniversityGuangzhou 510632China The Institute of Mobile Communications Southwest Jiaotong UniversityChengdu 610031China The State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong UniversityBeijing 100044China The School of Information Engineering Nanchang UniversityNanchang 330031China

This paper proposes some low complexity algorithms for active user detection(AUD),channel estimation(CE)and multi-user detection(MUD)in uplink non-orthogonal multiple access(NOMA)systems,including single-carrier and multi-carrier *** particular,we first propose a novel algorithm to estimate the active users and the channels for single-carrier based on complex alternating direction method of multipliers(ADMM),where fast decaying feature of non-zero components in sparse signal is *** importantly,the reliable estimated information is used for AUD,and the unreliable information will be further handled based on estimated symbol energy and total accurate or approximate number of active ***,the proposed algorithm for AUD in single-carrier model can be extended to multi-carrier case by exploiting the block sparse ***,we propose a low complexity MUD detection algorithm based on alternating minimization to estimate the active users’data,which avoids the Hessian matrix *** convergence and the complexity of proposed algorithms are analyzed and discussed *** results show that the proposed algorithms have better performance in terms of AUD,CE and ***,we can detect active users perfectly for multi-carrier NOMA system.

关键词： non-orthogonal multiple access massive connection active user detection channel estimation multi-user detection and alternating direction method of multipliers