Human parainfluenza viruses(HPIV)are common viral pathogens in acute respiratory infection(ARI).We aimed to describe the epidemiological and molecular characteristics of HPIV from ARI patients.This cross-sectional stu...Human parainfluenza viruses(HPIV)are common viral pathogens in acute respiratory infection(ARI).We aimed to describe the epidemiological and molecular characteristics of HPIV from ARI patients.This cross-sectional study was conducted using respiratory samples from 9,696 ARI patients between 2016 and 2020 in southern China.All samples were analyzed by quantitative real-time polymerase chain reaction to determine the presence of HPIV and other common respiratory viruses.Descriptive statistics were performed to determine the temporal and population distribution of HPIV.The fulllength hemagglutinin-neuraminidase(HN)gene of HPIV3-positive samples was sequenced for phylogenetic analysis.A total of 577(6.0%)patients tested positive for HPIV,with HPIV3 being the predominant serotype,accounting for 46.8%of cases.Notably,66.0%of these HPIV-positive cases were children aged 0-2 years.The prevalence of HPIV infections showed a decreased trend and altered peak during 2016-2020.Cough,fever,sputum production,and rhinorrhea were common respiratory symptoms in HPIV-positive patients.The majority of cases had pneumonia(63.4%).Human rhinovirus(HRV)and human coronavirus(HCoV)were the most common coinfection viruses in HPIV-positive cases,with proportions of 20.1%and 14.4%,respectively.Phylogenetic analysis revealed that the predominant lineage of HPIV3 was C3f(86.0%),followed by lineage C3a(8.0%),C3d(4.0%),and C3b(2.0%).These findings help to better understand the epidemiology of HPIV,and improve public health strategies to prevent and control HPIV infections in southern China.展开更多
This paper considers a multi-antenna ac-cess point(AP)transmitting secrecy message to a single-antenna user in the presence of a single-antenna illegal eavesdropper(Eve)and proposes a double ac-tive reconfigurable int...This paper considers a multi-antenna ac-cess point(AP)transmitting secrecy message to a single-antenna user in the presence of a single-antenna illegal eavesdropper(Eve)and proposes a double ac-tive reconfigurable intelligent surfaces(DARISs)as-sisted physical layer security(PLS)scheme denoted by DARISs-PLS to protect the secrecy message trans-mission.We formulate a secrecy rate maximization problem for the proposed DARISs-PLS scheme by considering a power budget constraint for the two ac-tive reconfigurable intelligent surfaces(ARISs)and AP.To address the formulated optimization problem,we jointly optimize the reflecting coefficients for the two ARISs and the beamforming at the AP in an it-erative manner by applying Dinkelbach based alter-nating optimization(AO)algorithm and a customized iterative algorithm together with the semidefinite re-laxation(SDR).Numerical results reveal that the pro-posed DARISs-PLS scheme outperforms the dou-ble passive reconfigurable intelligent surfaces-assisted PLS method(DPRISs-PLS)and single ARIS-assisted PLS method(SARIS-PLS)in terms of the secrecy rate.展开更多
This paper explores a UAV-mounted active Reconfigurable Intelligent Surface(aRIS)network designed to enhance secure downlink communication for multiple users while mitigating the impact of multiple Eavesdroppers(EVs)....This paper explores a UAV-mounted active Reconfigurable Intelligent Surface(aRIS)network designed to enhance secure downlink communication for multiple users while mitigating the impact of multiple Eavesdroppers(EVs).The focus is on optimizing the UAV’s trajectory,the Base Station’s(BS)transmit beamforming,and the power-Amplified Programmable Reflecting Elements(APREs)of the aRIS to maximize the minimum secrecy rate in the presence of EVs.This is a complex non-convex problem due to multiple optimization variables,high-dimensional matrix operations,and log-determinant objective functions,which makes it challenging to solve.Hence,a Successive Convex Approximation(SCA)-based optimization strategy is developed to efficiently solve the subproblems related to the UAV’s trajectory,aRIS’s APREs,and BS’s beamforming.By leveraging slack variables and approximation techniques,we solve the nonconvex subproblems by a sequence of convex subproblems.Simulation results demonstrate that the proposed UAV-aRIS network significantly outperforms its passive RIS counterpart in improving communication security,highlighting the effectiveness of the optimization strategy.展开更多
In this paper,we examine an illegal wireless communication network consisting of an illegal user receiving illegal signals from an illegal station and propose an active reconfigurable intelligent surface(ARIS)-assiste...In this paper,we examine an illegal wireless communication network consisting of an illegal user receiving illegal signals from an illegal station and propose an active reconfigurable intelligent surface(ARIS)-assisted multi-antenna jamming(MAJ)scheme denoted by ARIS-MAJ to interfere with the illegal signal transmission.In order to strike a balance between the jamming performance and the energy consumption,we consider a so-called jamming energy efficiency(JEE)which is defined as the ratio of achievable rate reduced by the jamming system to the corresponding power consumption.We formulate an optimization problem to maximize the JEE for the proposed ARIS-MAJ scheme by jointly optimizing the jammer’s beamforming vector and ARIS’s reflecting coefficients under the constraint that the jamming power received at the illegal user is lower than the illegal user’s detection threshold.To address the non-convex optimization problem,we propose the Dinkelbach-based alternating optimization(AO)algorithm by applying the semidefinite relaxation(SDR)algorithm with Gaussian randomization method.Numerical results validate that the proposed ARIS-MAJ scheme outperforms the passive reconfigurable intelligent surface(PRIS)-assisted multi-antenna jamming(PRIS-MAJ)scheme and the conventional multiantenna jamming scheme without RIS(NRIS-MAJ)in terms of the JEE.展开更多
在水声通信中,扩频通信具有可靠性高、抗多径能力强等特点,适合于远程或低信噪比情况下的通信;但另一方面,由于其带宽利用率低加之水声信道带宽有限,通信系统的数据率将受到很大的限制。为了提高数据率,提出了一种正交M-ary/DS扩频方法...在水声通信中,扩频通信具有可靠性高、抗多径能力强等特点,适合于远程或低信噪比情况下的通信;但另一方面,由于其带宽利用率低加之水声信道带宽有限,通信系统的数据率将受到很大的限制。为了提高数据率,提出了一种正交M-ary/DS扩频方法,该方法将正交直接序列(DS)扩频与并行M-ary扩频结合在一起,能够显著提高水声通信系统的数据率与带宽利用率。经过湖上实验验证,该方法在25 km距离约0 dB的接收信噪比下,采用63、127长度G o ld序列并通过RAKE接收,分别实现了对480个符号的无误码传输,数据率为381.0 b its/s与220.5 b its/s,其带宽利用率与使用相同序列的直接序列扩频相比提高了约一个数量级。展开更多
基金supported by grants from the National Mega Project on Major Infectious Disease Prevention of China(2017ZX10103011)Guangdong Marine Economy Development Special Project of China(NO.GDNRC[2022]35)+1 种基金the National Natural Science Foundation of China(82171675,82101775,82071352,82341094)Guangdong Basic and Applied Basic Research Foundation of China(2022A1515011156).
文摘Human parainfluenza viruses(HPIV)are common viral pathogens in acute respiratory infection(ARI).We aimed to describe the epidemiological and molecular characteristics of HPIV from ARI patients.This cross-sectional study was conducted using respiratory samples from 9,696 ARI patients between 2016 and 2020 in southern China.All samples were analyzed by quantitative real-time polymerase chain reaction to determine the presence of HPIV and other common respiratory viruses.Descriptive statistics were performed to determine the temporal and population distribution of HPIV.The fulllength hemagglutinin-neuraminidase(HN)gene of HPIV3-positive samples was sequenced for phylogenetic analysis.A total of 577(6.0%)patients tested positive for HPIV,with HPIV3 being the predominant serotype,accounting for 46.8%of cases.Notably,66.0%of these HPIV-positive cases were children aged 0-2 years.The prevalence of HPIV infections showed a decreased trend and altered peak during 2016-2020.Cough,fever,sputum production,and rhinorrhea were common respiratory symptoms in HPIV-positive patients.The majority of cases had pneumonia(63.4%).Human rhinovirus(HRV)and human coronavirus(HCoV)were the most common coinfection viruses in HPIV-positive cases,with proportions of 20.1%and 14.4%,respectively.Phylogenetic analysis revealed that the predominant lineage of HPIV3 was C3f(86.0%),followed by lineage C3a(8.0%),C3d(4.0%),and C3b(2.0%).These findings help to better understand the epidemiology of HPIV,and improve public health strategies to prevent and control HPIV infections in southern China.
基金supported in part by the National Natural Science Foundation of China under Grant 62071253,Grant 62371252 and Grant 62271268in part by the Jiangsu Provincial Key Research and Development Program under Grant BE2022800in part by the Jiangsu Provincial 333 Talent Project.
文摘This paper considers a multi-antenna ac-cess point(AP)transmitting secrecy message to a single-antenna user in the presence of a single-antenna illegal eavesdropper(Eve)and proposes a double ac-tive reconfigurable intelligent surfaces(DARISs)as-sisted physical layer security(PLS)scheme denoted by DARISs-PLS to protect the secrecy message trans-mission.We formulate a secrecy rate maximization problem for the proposed DARISs-PLS scheme by considering a power budget constraint for the two ac-tive reconfigurable intelligent surfaces(ARISs)and AP.To address the formulated optimization problem,we jointly optimize the reflecting coefficients for the two ARISs and the beamforming at the AP in an it-erative manner by applying Dinkelbach based alter-nating optimization(AO)algorithm and a customized iterative algorithm together with the semidefinite re-laxation(SDR).Numerical results reveal that the pro-posed DARISs-PLS scheme outperforms the dou-ble passive reconfigurable intelligent surfaces-assisted PLS method(DPRISs-PLS)and single ARIS-assisted PLS method(SARIS-PLS)in terms of the secrecy rate.
基金co-supported by Technology Key Project of Guangdong Province,China(No.HZJBGS-2021001)the Shanghai Sailing Scholar,China(No.23YF1412700)+1 种基金the National Natural Science Foundation of China(No.61901254)the Shanghai Technical Service Computing Center of Science and Engineering,Shanghai University,China.
文摘This paper explores a UAV-mounted active Reconfigurable Intelligent Surface(aRIS)network designed to enhance secure downlink communication for multiple users while mitigating the impact of multiple Eavesdroppers(EVs).The focus is on optimizing the UAV’s trajectory,the Base Station’s(BS)transmit beamforming,and the power-Amplified Programmable Reflecting Elements(APREs)of the aRIS to maximize the minimum secrecy rate in the presence of EVs.This is a complex non-convex problem due to multiple optimization variables,high-dimensional matrix operations,and log-determinant objective functions,which makes it challenging to solve.Hence,a Successive Convex Approximation(SCA)-based optimization strategy is developed to efficiently solve the subproblems related to the UAV’s trajectory,aRIS’s APREs,and BS’s beamforming.By leveraging slack variables and approximation techniques,we solve the nonconvex subproblems by a sequence of convex subproblems.Simulation results demonstrate that the proposed UAV-aRIS network significantly outperforms its passive RIS counterpart in improving communication security,highlighting the effectiveness of the optimization strategy.
基金supported in part by the National Natural Science Foundation of China under Grant 62071253,Grant 62371252 and Grant 62271268in part by the Jiangsu Provincial Key Research and Development Program under Grant BE2022800in part by the Jiangsu Provincial 333 Talent Project.
文摘In this paper,we examine an illegal wireless communication network consisting of an illegal user receiving illegal signals from an illegal station and propose an active reconfigurable intelligent surface(ARIS)-assisted multi-antenna jamming(MAJ)scheme denoted by ARIS-MAJ to interfere with the illegal signal transmission.In order to strike a balance between the jamming performance and the energy consumption,we consider a so-called jamming energy efficiency(JEE)which is defined as the ratio of achievable rate reduced by the jamming system to the corresponding power consumption.We formulate an optimization problem to maximize the JEE for the proposed ARIS-MAJ scheme by jointly optimizing the jammer’s beamforming vector and ARIS’s reflecting coefficients under the constraint that the jamming power received at the illegal user is lower than the illegal user’s detection threshold.To address the non-convex optimization problem,we propose the Dinkelbach-based alternating optimization(AO)algorithm by applying the semidefinite relaxation(SDR)algorithm with Gaussian randomization method.Numerical results validate that the proposed ARIS-MAJ scheme outperforms the passive reconfigurable intelligent surface(PRIS)-assisted multi-antenna jamming(PRIS-MAJ)scheme and the conventional multiantenna jamming scheme without RIS(NRIS-MAJ)in terms of the JEE.
文摘在水声通信中,扩频通信具有可靠性高、抗多径能力强等特点,适合于远程或低信噪比情况下的通信;但另一方面,由于其带宽利用率低加之水声信道带宽有限,通信系统的数据率将受到很大的限制。为了提高数据率,提出了一种正交M-ary/DS扩频方法,该方法将正交直接序列(DS)扩频与并行M-ary扩频结合在一起,能够显著提高水声通信系统的数据率与带宽利用率。经过湖上实验验证,该方法在25 km距离约0 dB的接收信噪比下,采用63、127长度G o ld序列并通过RAKE接收,分别实现了对480个符号的无误码传输,数据率为381.0 b its/s与220.5 b its/s,其带宽利用率与使用相同序列的直接序列扩频相比提高了约一个数量级。
