Opportunistic networks are random networks and do not communicate with each other among respective communication areas.This situation leads to great difficulty in message transfer.This paper proposes a reducing energy...Opportunistic networks are random networks and do not communicate with each other among respective communication areas.This situation leads to great difficulty in message transfer.This paper proposes a reducing energy consumption optimal selection of path transmission(OSPT) routing algorithm in opportunistic networks.This algorithm designs a dynamic random network topology,creates a dynamic link,and realizes an optimized selected path.This algorithm solves a problem that nodes are unable to deliver messages for a long time in opportunistic networks.According to the simulation experiment,OSPT improves deliver ratio,and reduces energy consumption,cache time and transmission delay compared with the Epidemic Algorithm and Spray and Wait Algorithm in opportunistic networks.展开更多
The structures of the space switching and the wavelength switching optical cross connect (OXC) nodes which are based on the arrayed waveguide grating (AWG) multiplexer are analyzed.By the matrix transformation relatio...The structures of the space switching and the wavelength switching optical cross connect (OXC) nodes which are based on the arrayed waveguide grating (AWG) multiplexer are analyzed.By the matrix transformation relation between the input and output wavelengths of the AWG multiplexer, the wavelength transmission routings of the space switching and wavelength switching OXC nodes are determined.展开更多
In order to minimize the energy consumption in the discovery of the routing path, this paper introduces a novel concept of effective transmission (ET) that ensures each forwarding node is not only farther from the s...In order to minimize the energy consumption in the discovery of the routing path, this paper introduces a novel concept of effective transmission (ET) that ensures each forwarding node is not only farther from the source node, but also nearer to the destination node with respect to its sender, An energ-aware routing protocol based on ET is proposed. It enables the energy consumption for each hop to be the least for the transmission. The simulation results show the routing protocol is effective in the performance of energy consumption comparing with some other routing protocols.展开更多
The improvement of the quality and efficiency of vehicle wireless network data transmission is always a key concern in the Internet of Vehicles(IoV).Routing transmission solved the limitation of transmission distance ...The improvement of the quality and efficiency of vehicle wireless network data transmission is always a key concern in the Internet of Vehicles(IoV).Routing transmission solved the limitation of transmission distance to a certain extent.Traditional routing algorithm cannot adapt to complex traffic environment,resulting in low transmission efficiency.In order to improve the transmission success rate and quality of vehicle network routing transmission,make the routing algorithm more suitable for complex traffic environment,and reduce transmission power consumption to improve energy efficiency,a comprehensive optimized routing transmission algorithm is proposed.Based on the routing transmission algorithm,an optimization algorithmbased on road condition,vehicle status and network performance is proposed to improve the success rate of routing transmission in the IoV.Relative distance difference and density are used as decision-making indicators to measure Road Side Unit(RSU)assisted transmission.And the Ambient backscatter communication(AmBC)technology and energy collection are used to reduce the energy consumption of routing relay transmission.An energy collection optimization algorithm is proposed to optimize the energy efficiency of AmBC and improve the energy efficiency of transmission.Simulation results show that the proposed routing optimization algorithm can effectively improve the success rate of packet transmission in vehicular ad hoc networks(VANETs),and theAmBC optimization algorithmcan effectively reduce energy consumption in the transmission process.The proposed optimization algorithm achieves comprehensive optimization of routing transmission performance and energy efficiency.展开更多
In recent years,Software Defined Networking(SDN)has become an important candidate for communication infrastructure in smart cities.It produces a drastic increase in the need for delivery of video services that are of ...In recent years,Software Defined Networking(SDN)has become an important candidate for communication infrastructure in smart cities.It produces a drastic increase in the need for delivery of video services that are of high resolution,multiview,and large-scale in nature.However,this entity gets easily influenced by heterogeneous behaviour of the user’s wireless link features that might reduce the quality of video stream for few or all clients.The development of SDN allows the emergence of new possibilities for complicated controlling of video conferences.Besides,multicast routing protocol with multiple constraints in terms of Quality of Service(QoS)is a Nondeterministic Polynomial time(NP)hard problem which can be solved only with the help of metaheuristic optimization algorithms.With this motivation,the current research paper presents a new Improved BlackWidow Optimization with Levy Distribution model(IBWO-LD)-based multicast routing protocol for smart cities.The presented IBWO-LD model aims at minimizing the energy consumption and bandwidth utilization while at the same time accomplish improved quality of video streams that the clients receive.Besides,a priority-based scheduling and classifier model is designed to allocate multicast request based on the type of applications and deadline constraints.A detailed experimental analysis was carried out to ensure the outcomes improved under different aspects.The results from comprehensive comparative analysis highlighted the superiority of the proposed IBWO-LD model over other compared methods.展开更多
The successful rate of transmission coordination of opportunistic routing (OK) is analyzea systematically, and then two efficient transmission coordination mechanisms (TCMs) are proposed for OR: a batch sliding w...The successful rate of transmission coordination of opportunistic routing (OK) is analyzea systematically, and then two efficient transmission coordination mechanisms (TCMs) are proposed for OR: a batch sliding window-based TCM and a bit map-based TCM, to reduce the total number of packet transmissions and improve end-to-end throughput for OR. The batch sliding window-based TCM avoids the oscillation of the successful rate of transmission coordination by transmitting packets in continuous batch mode so as to improve the average successful rate of transmission coordination efficiently, while the bit map-based TCM improves end-to-end throughput of OR by reducing the overhead of transmission coordination. Exhaustive simulations show that the average end-to-end throughput gains of the two proposed TCMs are 15.4% and 6.4% over the batch map-based TCM, respectively.展开更多
The necessary background as well as the details of simulation was presented to simulate and evaluate the performance of the ad hoc on-demand distance vector routing protocol in mobile ad hoc network with the help of t...The necessary background as well as the details of simulation was presented to simulate and evaluate the performance of the ad hoc on-demand distance vector routing protocol in mobile ad hoc network with the help of the network simulator NS2 using the common transmission range to deliver the data packets at the destination node. The number of participating nodes played an important role to predict the conditions for the best performance of the protocol with respect to throughput, delay, packet delivery ratio, drop packets, consumed and residual energy of the network. Further, the efforts can be put to control the transmission range dynamically and overheads for reducing the energy consumption in the network and improving its lifetime of the nodes and the lifespan of the network.展开更多
Background:Many healthcare workers were infected by coronavirus disease 2019(COVID-19)early in the epidemic posing a big challenge for epidemic control.Hence,this study aims to explore perceived infection routes,influ...Background:Many healthcare workers were infected by coronavirus disease 2019(COVID-19)early in the epidemic posing a big challenge for epidemic control.Hence,this study aims to explore perceived infection routes,influencing factors,psychosocial changes,and management procedures for COVID-19 infected healthcare workers.Methods:This is a cross-sectional,single hospital-based study.We recruited all 105 confirmed COVID-19 healthcare workers in the Zhongnan Hospital of Wuhan University from February 15 to 29,2020.All participants completed a validated questionnaire.Electronic consent was obtained from all participants.Perceived causes of infection,infection prevention,control knowledge and behaviour,psychological changes,symptoms and treatment were measured.Results:Finally,103 professional staff with COVID-19 finished the questionnaire and was included(response rate:98.1%).Of them,87 cases(84.5%)thought they were infected in working environment in hospital,one(1.0%)thought their infection was due to the laboratory environment,and 5(4.9%)thought they were infected in daily life or community environment.Swab of throat collection and physical examination were the procedures perceived as most likely causing their infection by nurses and doctors respectively.Forty-three(41.8%)thought their infection was related to protective equipment,utilization of common equipment(masks and gloves).The top three first symptoms displayed before diagnosis were fever(41.8%),lethargy(33.0%)and muscle aches(30.1%).After diagnosis,88.3%staff experienced psychological stress or emotional changes during their isolation period,only 11.7%had almost no emotional changes.Arbidol(Umifenovir;an anti-influza drug;69.2%)was the drug most commonly used to target infection in mild and moderate symptoms.Conclusion:The main perceived mode of transmission was not maintaining protection when working at a close distance and having intimate contact with infected cases.Positive psychological intervention is necessary.展开更多
Large-scale wireless sensor networks(WSNs)play a critical role in monitoring dangerous scenarios and responding to medical emergencies.However,the inherent instability and error-prone nature of wireless links present ...Large-scale wireless sensor networks(WSNs)play a critical role in monitoring dangerous scenarios and responding to medical emergencies.However,the inherent instability and error-prone nature of wireless links present significant challenges,necessitating efficient data collection and reliable transmission services.This paper addresses the limitations of existing data transmission and recovery protocols by proposing a systematic end-to-end design tailored for medical event-driven cluster-based large-scale WSNs.The primary goal is to enhance the reliability of data collection and transmission services,ensuring a comprehensive and practical approach.Our approach focuses on refining the hop-count-based routing scheme to achieve fairness in forwarding reliability.Additionally,it emphasizes reliable data collection within clusters and establishes robust data transmission over multiple hops.These systematic improvements are designed to optimize the overall performance of the WSN in real-world scenarios.Simulation results of the proposed protocol validate its exceptional performance compared to other prominent data transmission schemes.The evaluation spans varying sensor densities,wireless channel conditions,and packet transmission rates,showcasing the protocol’s superiority in ensuring reliable and efficient data transfer.Our systematic end-to-end design successfully addresses the challenges posed by the instability of wireless links in large-scaleWSNs.By prioritizing fairness,reliability,and efficiency,the proposed protocol demonstrates its efficacy in enhancing data collection and transmission services,thereby offering a valuable contribution to the field of medical event-drivenWSNs.展开更多
The pathogenicity of white spot syndrome virus (WSSV) to zooplankton species, rotifer Brachionus urceus (Linnaeus), copepod Acartia clausi (Giesbrecht) and mysid shrimp Neomysis awatschensis ( Brandt ), was es...The pathogenicity of white spot syndrome virus (WSSV) to zooplankton species, rotifer Brachionus urceus (Linnaeus), copepod Acartia clausi (Giesbrecht) and mysid shrimp Neomysis awatschensis ( Brandt ), was estimated by immersion challenge and virus - phytoplankton adhesion mute to investigate a potential new transmission mute of WSSV to zooplankton. WSSV succeeded in infecting these zooplankton species and nested-PCR revealed positive results for the virus - phytoplankton adhesion mute, whereas WSSV cannot infect zooplankton by immersion challenge. These results indicated that virus - phytoplankton adhesion route is a successful new transmission mute of WSSV to zooplankton and also implied that phytoplankton could be a carrier in WSSV transmission.展开更多
To further investigate the vertical transmission route of human papillomavirus (HPV) and the indication for the choice of mode of delivery, the infective status of 152 asymptomatic pregnant wemen and the maternal-feta...To further investigate the vertical transmission route of human papillomavirus (HPV) and the indication for the choice of mode of delivery, the infective status of 152 asymptomatic pregnant wemen and the maternal-fetal transmission were studied. By using general primers in polymerase chain reaction (GP-PCR) combined with restriction fragment length polymorphism analysis, HPV DNA positive rate in cervical secretions and venous blood in asymptomatic pregnant women was 36.21 % and 52.78 %, respectively, and the identified genotypes were mainly HPV_16 and _18. The maternal-fetal transmission rate of HPV via genital tract as well as blood was 40.91 % and 57.89 %, respectively. It was concluded that besides the transmission route of genital tract and amniotic fluid, there was also transplacental transmission of HPV in utero. Therefore,in our opinion, it is not an absolut indication to perform a cesarean delivery for the pregnant women with HPV asymtomatic genital infection.展开更多
高速服务器主板主芯片到存储器的高速信号传输通过Double Data Rate(简称DDR)技术实现,传输高速信号的连接线简称为DDR阻抗线。因主芯片相对存储器位置能布设管脚的空间要小,从主芯片到存储器的DDR高速阻抗线呈扇出形状,主芯片位置的阻...高速服务器主板主芯片到存储器的高速信号传输通过Double Data Rate(简称DDR)技术实现,传输高速信号的连接线简称为DDR阻抗线。因主芯片相对存储器位置能布设管脚的空间要小,从主芯片到存储器的DDR高速阻抗线呈扇出形状,主芯片位置的阻抗线线宽相对存储器位置要小,存在阻抗不连续问题。对靠近主芯片位置的DDR阻抗线增加规则的凸耳状走线可提升整段DDR阻抗不匹配问题。增加规则的凸耳走线的阻抗线又称Tabbed Routiing阻抗(简称TAB阻抗)。探究布设不同形状和不同尺寸的TAB设计来提升阻抗不连续问题,根据材料等级选择一种最佳的布线设计模式,对TAB阻抗设计及生产制作控制都有较大指导意义。展开更多
Most knowledgeable people agree that networking and routing technologies have been around about 25 years. Routing is simultaneously the most complicated function of a network and the most important. It is of the same ...Most knowledgeable people agree that networking and routing technologies have been around about 25 years. Routing is simultaneously the most complicated function of a network and the most important. It is of the same kind that more than 70% of computer application fields are MIS applications. So the challenge in building and using a MIS in the network is developing the means to find, access, and communicate large databases or multi databases systems. Because general databases are not time continuous, in fact, they can not be streaming, so we can't obtain reliable and secure quality of service by deleting some unimportant datagrams in the databases transmission. In this article, we will discuss which kind of routing protocol is the best type for large databases or multi databases systems transmission in the networks.展开更多
Underground subway platforms are among the world’s busiest public transportation systems,but the airborne transmission mechanism of respiratory infections on these platforms has been rarely studied.Here,computational...Underground subway platforms are among the world’s busiest public transportation systems,but the airborne transmission mechanism of respiratory infections on these platforms has been rarely studied.Here,computational fluid dynamics(CFD)modeling is used to investigate the airflow patterns and infection risks in an island platform under two common ventilation modes:Mode 1-both sides have air inlets and outlets;Mode 2-air inlets are present at the two sides and outlets are present in the middle.Under the investigated scenario,airflow structure is characterized by the ventilation jet and human thermal plumes.Their interaction with the infector’s breathing jet imposes the front passenger under the highest exposure risk by short-range airborne route,with intake fractions up to 2.57%(oral breathing)or 0.63%(nasal breathing)under Mode 1;oral breathing of the infector may impose higher risks for the front passenger compared with nasal breathing.Pathogen are efficiently diluted as they travel further,in particular to adjacent crowds.The maximum and median value of intake fractions of passengers in adjacent crowds are respectively 0.093%and 0.016%(oral breathing),and 0.073%and 0.014%(nasal breathing)under Mode 1.Compared with Mode 1,the 2nd mode minimizes the interaction of ventilation jet and breathing jet,where the maximum intake fraction is only 0.34%,and the median value in the same crowd and other crowds are reduced by 23–63%.Combining published quanta generation rate data of COVID-19 and influenza infectors,the predicted maximum and median infection risks for passengers in the same crowds are respectively 1.46%–40.23%and 0.038%–1.67%during the 3–10 min waiting period,which are more sensitive to ventilation rate and exposure time compared with return air.This study can provide practical guidance for the prevention of respiratory infections in subway platforms.展开更多
Improved traditional ant colony algorithms,a data routing model used to the data remote exchange on WAN was presented.In the model,random heuristic factors were introduced to realize multi-path search.The updating mod...Improved traditional ant colony algorithms,a data routing model used to the data remote exchange on WAN was presented.In the model,random heuristic factors were introduced to realize multi-path search.The updating model of pheromone could adjust the pheromone concentration on the optimal path according to path load dynamically to make the system keep load balance.The simulation results show that the improved model has a higher performance on convergence and load balance.展开更多
The huge increase in the communication network rate has made the application fields and scenarios for vehicular ad hoc networks more abundant and diversified and proposed more requirements for the efficiency and quali...The huge increase in the communication network rate has made the application fields and scenarios for vehicular ad hoc networks more abundant and diversified and proposed more requirements for the efficiency and quality of data transmission.To improve the limited communication distance and poor communication quality of the Internet of Vehicles(IoV),an optimal intelligent routing algorithm is proposed in this paper.Combined multiweight decision algorithm with the greedy perimeter stateless routing protocol,designed and evaluated standardized function for link stability.Linear additive weighting is used to optimize link stability and distance to improve the packet delivery rate of the IoV.The blockchain system is used as the storage structure for relay data,and the smart contract incentive algorithm based on machine learning is used to encourage relay vehicles to provide more communication bandwidth for data packet transmission.The proposed scheme is simulated and analyzed under different scenarios and different parameters.The experimental results demonstrate that the proposed scheme can effectively reduce the packet loss rate and improve system performance.展开更多
Opportunistic routing(OR) is an effective way to guarantee transmission reliability in wireless multi-hop networks.However,little research focuses on transmission efficiency.Thus,an analytical model based on open queu...Opportunistic routing(OR) is an effective way to guarantee transmission reliability in wireless multi-hop networks.However,little research focuses on transmission efficiency.Thus,an analytical model based on open queuing network with Markov chains was proposed to evaluate the efficiency.By analyzing two typical ORs,we find duplicate transmission and collision avoidance overhead are the root reasons behind inefficiency.Therefore,a new scheme called dual priority cooperative opportunistic routing(DPCOR) was proposed.In DPCOR,forwarding candidates are configured with dual priority,which enables the network to classify forwarding candidates more effectively so as to reduce the back-off time and obtain more diversity gain.Theoretical analysis and simulation results show DPCOR achieves significant performance improvement with less time overhead compared with traditional routings and typical ORs.展开更多
With the explosive advancements in wireless communications and digital electronics,some tiny devices,sensors,became a part of our daily life in numerous elds.Wireless sensor networks(WSNs)is composed of tiny sensor de...With the explosive advancements in wireless communications and digital electronics,some tiny devices,sensors,became a part of our daily life in numerous elds.Wireless sensor networks(WSNs)is composed of tiny sensor devices.WSNs have emerged as a key technology enabling the realization of the Internet of Things(IoT).In particular,the sensor-based revolution of WSN-based IoT has led to considerable technological growth in nearly all circles of our life such as smart cities,smart homes,smart healthcare,security applications,environmental monitoring,etc.However,the limitations of energy,communication range,and computational resources are bottlenecks to the widespread applications of this technology.In order to tackle these issues,in this paper,we propose an Energy-efcient Transmission Range Optimized Model for IoT(ETROMI),which can optimize the transmission range of the sensor nodes to curb the hot-spot problem occurring in multi-hop communication.In particular,we maximize the transmission range by employing linear programming to alleviate the sensor nodes’energy consumption and considerably enhance the network longevity compared to that achievable using state-of-the-art algorithms.Through extensive simulation results,we demonstrate the superiority of the proposed model.ETROMI is expected to be extensively used for various smart city,smart home,and smart healthcare applications in which the transmission range of the sensor nodes is a key concern.展开更多
In order to improve the data transmission reliability of mobile ad hoc network, a routing scheme called integrated forward error correction multipath routing protocol was proposed, which integrates the techniques of p...In order to improve the data transmission reliability of mobile ad hoc network, a routing scheme called integrated forward error correction multipath routing protocol was proposed, which integrates the techniques of packet fragmenting and forward error correction encoding into multipath routing. The scheme works as follows: adding a certain redundancy into the original packets; fragmenting the resulting packets into exclusive blocks of the same size; encoding with the forward error correction technique, and then sending them to the destination node. When the receiving end receives a certain amount of information blocks, the original information will be recovered even with partial loss. The performance of the scheme was evaluated using OPNET modeler. The experimental results show that with the method the average transmission delay is decreased by 20% and the transmission reliability is increased by 30%.展开更多
With the wide application of antibiotics in medicine and industry fields as well as the improvement of water quality detection technology,more and more reports show that antibiotics and antibiotic resistance genes(AGR...With the wide application of antibiotics in medicine and industry fields as well as the improvement of water quality detection technology,more and more reports show that antibiotics and antibiotic resistance genes(AGRs)were detected in various drinking water sources.The existence of these pollutants in water environment posed a great threat to human health.In this paper,the pollution status of antibiotics and transmission routes of antibiotic genes were introduced,and the characteristics and shortcomings of antibiotic treatment technology both at home and abroad were analyzed.Finally,suggestions and prospects for future antibiotic treatment technology were put forward.展开更多
基金Supported by the National Natural Science Foundation of China(No.61379057,61073186,61309001,61379110,61103202)Doctoral Fund of Ministry of Education of China(No.20120162130008)the National Basic Research Program of China(973 Program)(No.2014CB046305)
文摘Opportunistic networks are random networks and do not communicate with each other among respective communication areas.This situation leads to great difficulty in message transfer.This paper proposes a reducing energy consumption optimal selection of path transmission(OSPT) routing algorithm in opportunistic networks.This algorithm designs a dynamic random network topology,creates a dynamic link,and realizes an optimized selected path.This algorithm solves a problem that nodes are unable to deliver messages for a long time in opportunistic networks.According to the simulation experiment,OSPT improves deliver ratio,and reduces energy consumption,cache time and transmission delay compared with the Epidemic Algorithm and Spray and Wait Algorithm in opportunistic networks.
基金NationalKeyLabofBroadBandFiberTransmissionandCommunicatonSystemTechnology ElectronicUniversityofScienceandTechnology China
文摘The structures of the space switching and the wavelength switching optical cross connect (OXC) nodes which are based on the arrayed waveguide grating (AWG) multiplexer are analyzed.By the matrix transformation relation between the input and output wavelengths of the AWG multiplexer, the wavelength transmission routings of the space switching and wavelength switching OXC nodes are determined.
基金Supported by the National Natural Science Foun-dation of China (60572049) the Natural Science Foundation ofHubei Province of China (2005ABA264)
文摘In order to minimize the energy consumption in the discovery of the routing path, this paper introduces a novel concept of effective transmission (ET) that ensures each forwarding node is not only farther from the source node, but also nearer to the destination node with respect to its sender, An energ-aware routing protocol based on ET is proposed. It enables the energy consumption for each hop to be the least for the transmission. The simulation results show the routing protocol is effective in the performance of energy consumption comparing with some other routing protocols.
基金This work was supported in part by the National Natural Science Foundation of China under Grant 62271192in part by Central Plains Talents Plan under Grant ZYYCYU202012173+9 种基金in part by theNationalKeyR&DProgramof China underGrant 2020YFB2008400in part by the Program of CEMEE under Grant 2022Z00202Bin part by the LAGEO of Chinese Academy of Sciences underGrantLAGEO-2019-2in part by the Program for Science and Technology Innovation Talents in the University of Henan Province under Grant 20HASTIT022in part by the Natural Science Foundation of Henan under Grant 202300410126in part by the Program for Innovative Research Team in University of Henan Province under Grant 21IRTSTHN015in part by the Equipment Pre-Research Joint Research Program of Ministry of Education under Grant 8091B032129in part by the Training Program for Young Scholar of Henan Province for Colleges and Universities under Grant 2020GGJS172in part by the Program for Science and Technology Innovation Talents in Universities of Henan Province under Grant 22HASTIT020in part by the Henan Province Science Fund for Distinguished Young Scholars under Grant 222300420006.
文摘The improvement of the quality and efficiency of vehicle wireless network data transmission is always a key concern in the Internet of Vehicles(IoV).Routing transmission solved the limitation of transmission distance to a certain extent.Traditional routing algorithm cannot adapt to complex traffic environment,resulting in low transmission efficiency.In order to improve the transmission success rate and quality of vehicle network routing transmission,make the routing algorithm more suitable for complex traffic environment,and reduce transmission power consumption to improve energy efficiency,a comprehensive optimized routing transmission algorithm is proposed.Based on the routing transmission algorithm,an optimization algorithmbased on road condition,vehicle status and network performance is proposed to improve the success rate of routing transmission in the IoV.Relative distance difference and density are used as decision-making indicators to measure Road Side Unit(RSU)assisted transmission.And the Ambient backscatter communication(AmBC)technology and energy collection are used to reduce the energy consumption of routing relay transmission.An energy collection optimization algorithm is proposed to optimize the energy efficiency of AmBC and improve the energy efficiency of transmission.Simulation results show that the proposed routing optimization algorithm can effectively improve the success rate of packet transmission in vehicular ad hoc networks(VANETs),and theAmBC optimization algorithmcan effectively reduce energy consumption in the transmission process.The proposed optimization algorithm achieves comprehensive optimization of routing transmission performance and energy efficiency.
基金The authors extend their appreciation to the Deanship of Scientific Research at King Khalid University for funding this work under Grant Number(RGP.1/282/42)Princess Nourah bint Abdulrahman University Researchers Supporting Project Number(PNURSP2022R191),Princess Nourah bint Abdulrahman University,Riyadh,Saudi Arabia.
文摘In recent years,Software Defined Networking(SDN)has become an important candidate for communication infrastructure in smart cities.It produces a drastic increase in the need for delivery of video services that are of high resolution,multiview,and large-scale in nature.However,this entity gets easily influenced by heterogeneous behaviour of the user’s wireless link features that might reduce the quality of video stream for few or all clients.The development of SDN allows the emergence of new possibilities for complicated controlling of video conferences.Besides,multicast routing protocol with multiple constraints in terms of Quality of Service(QoS)is a Nondeterministic Polynomial time(NP)hard problem which can be solved only with the help of metaheuristic optimization algorithms.With this motivation,the current research paper presents a new Improved BlackWidow Optimization with Levy Distribution model(IBWO-LD)-based multicast routing protocol for smart cities.The presented IBWO-LD model aims at minimizing the energy consumption and bandwidth utilization while at the same time accomplish improved quality of video streams that the clients receive.Besides,a priority-based scheduling and classifier model is designed to allocate multicast request based on the type of applications and deadline constraints.A detailed experimental analysis was carried out to ensure the outcomes improved under different aspects.The results from comprehensive comparative analysis highlighted the superiority of the proposed IBWO-LD model over other compared methods.
文摘The successful rate of transmission coordination of opportunistic routing (OK) is analyzea systematically, and then two efficient transmission coordination mechanisms (TCMs) are proposed for OR: a batch sliding window-based TCM and a bit map-based TCM, to reduce the total number of packet transmissions and improve end-to-end throughput for OR. The batch sliding window-based TCM avoids the oscillation of the successful rate of transmission coordination by transmitting packets in continuous batch mode so as to improve the average successful rate of transmission coordination efficiently, while the bit map-based TCM improves end-to-end throughput of OR by reducing the overhead of transmission coordination. Exhaustive simulations show that the average end-to-end throughput gains of the two proposed TCMs are 15.4% and 6.4% over the batch map-based TCM, respectively.
文摘The necessary background as well as the details of simulation was presented to simulate and evaluate the performance of the ad hoc on-demand distance vector routing protocol in mobile ad hoc network with the help of the network simulator NS2 using the common transmission range to deliver the data packets at the destination node. The number of participating nodes played an important role to predict the conditions for the best performance of the protocol with respect to throughput, delay, packet delivery ratio, drop packets, consumed and residual energy of the network. Further, the efforts can be put to control the transmission range dynamically and overheads for reducing the energy consumption in the network and improving its lifetime of the nodes and the lifespan of the network.
基金supported by the Emergency Science and Technology Project in Hubei Province(2020FCA008)
文摘Background:Many healthcare workers were infected by coronavirus disease 2019(COVID-19)early in the epidemic posing a big challenge for epidemic control.Hence,this study aims to explore perceived infection routes,influencing factors,psychosocial changes,and management procedures for COVID-19 infected healthcare workers.Methods:This is a cross-sectional,single hospital-based study.We recruited all 105 confirmed COVID-19 healthcare workers in the Zhongnan Hospital of Wuhan University from February 15 to 29,2020.All participants completed a validated questionnaire.Electronic consent was obtained from all participants.Perceived causes of infection,infection prevention,control knowledge and behaviour,psychological changes,symptoms and treatment were measured.Results:Finally,103 professional staff with COVID-19 finished the questionnaire and was included(response rate:98.1%).Of them,87 cases(84.5%)thought they were infected in working environment in hospital,one(1.0%)thought their infection was due to the laboratory environment,and 5(4.9%)thought they were infected in daily life or community environment.Swab of throat collection and physical examination were the procedures perceived as most likely causing their infection by nurses and doctors respectively.Forty-three(41.8%)thought their infection was related to protective equipment,utilization of common equipment(masks and gloves).The top three first symptoms displayed before diagnosis were fever(41.8%),lethargy(33.0%)and muscle aches(30.1%).After diagnosis,88.3%staff experienced psychological stress or emotional changes during their isolation period,only 11.7%had almost no emotional changes.Arbidol(Umifenovir;an anti-influza drug;69.2%)was the drug most commonly used to target infection in mild and moderate symptoms.Conclusion:The main perceived mode of transmission was not maintaining protection when working at a close distance and having intimate contact with infected cases.Positive psychological intervention is necessary.
文摘Large-scale wireless sensor networks(WSNs)play a critical role in monitoring dangerous scenarios and responding to medical emergencies.However,the inherent instability and error-prone nature of wireless links present significant challenges,necessitating efficient data collection and reliable transmission services.This paper addresses the limitations of existing data transmission and recovery protocols by proposing a systematic end-to-end design tailored for medical event-driven cluster-based large-scale WSNs.The primary goal is to enhance the reliability of data collection and transmission services,ensuring a comprehensive and practical approach.Our approach focuses on refining the hop-count-based routing scheme to achieve fairness in forwarding reliability.Additionally,it emphasizes reliable data collection within clusters and establishes robust data transmission over multiple hops.These systematic improvements are designed to optimize the overall performance of the WSN in real-world scenarios.Simulation results of the proposed protocol validate its exceptional performance compared to other prominent data transmission schemes.The evaluation spans varying sensor densities,wireless channel conditions,and packet transmission rates,showcasing the protocol’s superiority in ensuring reliable and efficient data transfer.Our systematic end-to-end design successfully addresses the challenges posed by the instability of wireless links in large-scaleWSNs.By prioritizing fairness,reliability,and efficiency,the proposed protocol demonstrates its efficacy in enhancing data collection and transmission services,thereby offering a valuable contribution to the field of medical event-drivenWSNs.
基金Funding for this research was provided by the National Natural Science Foundation of China under contract No. 30371111; the National "973" Project of China under contract No. G1999012011;the National" 863" Program of China under contract No. 2002AA648010 ; the Tenth National Five Year Major Program of China under contract No. 2001BAS05B.
文摘The pathogenicity of white spot syndrome virus (WSSV) to zooplankton species, rotifer Brachionus urceus (Linnaeus), copepod Acartia clausi (Giesbrecht) and mysid shrimp Neomysis awatschensis ( Brandt ), was estimated by immersion challenge and virus - phytoplankton adhesion mute to investigate a potential new transmission mute of WSSV to zooplankton. WSSV succeeded in infecting these zooplankton species and nested-PCR revealed positive results for the virus - phytoplankton adhesion mute, whereas WSSV cannot infect zooplankton by immersion challenge. These results indicated that virus - phytoplankton adhesion route is a successful new transmission mute of WSSV to zooplankton and also implied that phytoplankton could be a carrier in WSSV transmission.
文摘To further investigate the vertical transmission route of human papillomavirus (HPV) and the indication for the choice of mode of delivery, the infective status of 152 asymptomatic pregnant wemen and the maternal-fetal transmission were studied. By using general primers in polymerase chain reaction (GP-PCR) combined with restriction fragment length polymorphism analysis, HPV DNA positive rate in cervical secretions and venous blood in asymptomatic pregnant women was 36.21 % and 52.78 %, respectively, and the identified genotypes were mainly HPV_16 and _18. The maternal-fetal transmission rate of HPV via genital tract as well as blood was 40.91 % and 57.89 %, respectively. It was concluded that besides the transmission route of genital tract and amniotic fluid, there was also transplacental transmission of HPV in utero. Therefore,in our opinion, it is not an absolut indication to perform a cesarean delivery for the pregnant women with HPV asymtomatic genital infection.
文摘高速服务器主板主芯片到存储器的高速信号传输通过Double Data Rate(简称DDR)技术实现,传输高速信号的连接线简称为DDR阻抗线。因主芯片相对存储器位置能布设管脚的空间要小,从主芯片到存储器的DDR高速阻抗线呈扇出形状,主芯片位置的阻抗线线宽相对存储器位置要小,存在阻抗不连续问题。对靠近主芯片位置的DDR阻抗线增加规则的凸耳状走线可提升整段DDR阻抗不匹配问题。增加规则的凸耳走线的阻抗线又称Tabbed Routiing阻抗(简称TAB阻抗)。探究布设不同形状和不同尺寸的TAB设计来提升阻抗不连续问题,根据材料等级选择一种最佳的布线设计模式,对TAB阻抗设计及生产制作控制都有较大指导意义。
基金Supported by National Natural Science Foundation of China(6 98730 2 7)
文摘Most knowledgeable people agree that networking and routing technologies have been around about 25 years. Routing is simultaneously the most complicated function of a network and the most important. It is of the same kind that more than 70% of computer application fields are MIS applications. So the challenge in building and using a MIS in the network is developing the means to find, access, and communicate large databases or multi databases systems. Because general databases are not time continuous, in fact, they can not be streaming, so we can't obtain reliable and secure quality of service by deleting some unimportant datagrams in the databases transmission. In this article, we will discuss which kind of routing protocol is the best type for large databases or multi databases systems transmission in the networks.
基金financially supported by the Natural Science Foundation of Guangdong Province,China(2019A1515012121)Natural Science Foundation of Zhejiang Province,China(Y20E080078)NIAID center of excellence for influenza research and surveillance(HHSN2722014000006C)。
文摘Underground subway platforms are among the world’s busiest public transportation systems,but the airborne transmission mechanism of respiratory infections on these platforms has been rarely studied.Here,computational fluid dynamics(CFD)modeling is used to investigate the airflow patterns and infection risks in an island platform under two common ventilation modes:Mode 1-both sides have air inlets and outlets;Mode 2-air inlets are present at the two sides and outlets are present in the middle.Under the investigated scenario,airflow structure is characterized by the ventilation jet and human thermal plumes.Their interaction with the infector’s breathing jet imposes the front passenger under the highest exposure risk by short-range airborne route,with intake fractions up to 2.57%(oral breathing)or 0.63%(nasal breathing)under Mode 1;oral breathing of the infector may impose higher risks for the front passenger compared with nasal breathing.Pathogen are efficiently diluted as they travel further,in particular to adjacent crowds.The maximum and median value of intake fractions of passengers in adjacent crowds are respectively 0.093%and 0.016%(oral breathing),and 0.073%and 0.014%(nasal breathing)under Mode 1.Compared with Mode 1,the 2nd mode minimizes the interaction of ventilation jet and breathing jet,where the maximum intake fraction is only 0.34%,and the median value in the same crowd and other crowds are reduced by 23–63%.Combining published quanta generation rate data of COVID-19 and influenza infectors,the predicted maximum and median infection risks for passengers in the same crowds are respectively 1.46%–40.23%and 0.038%–1.67%during the 3–10 min waiting period,which are more sensitive to ventilation rate and exposure time compared with return air.This study can provide practical guidance for the prevention of respiratory infections in subway platforms.
基金Sponsored by the National High Technology Research and Development Program of China(2006AA701306)the National Innovation Foundation of Enterprises(05C26212200378)
文摘Improved traditional ant colony algorithms,a data routing model used to the data remote exchange on WAN was presented.In the model,random heuristic factors were introduced to realize multi-path search.The updating model of pheromone could adjust the pheromone concentration on the optimal path according to path load dynamically to make the system keep load balance.The simulation results show that the improved model has a higher performance on convergence and load balance.
基金supported by the National Key R&D Program of China (2020YFB2008400)LAGEO of Chinese Academy of Sciences (LAGEO-2019-2)+11 种基金Program for Science&Technology Innovation Talents in the University of Henan Province (20HASTIT022)21th Project of the Xizang Cultural Inheritance and Development Collaborative Innovation Center in 2018 (21IRTSTHN015)Natural Science Foundation of Xizang Named“Research of Key Technology of Millimeter Wave MIMO Secure Transmission with Relay Enhancement”in 2018Xizang Autonomous Region Education Science“13th Five-year Plan”Major Project for 2018 (XZJKY201803)Natural Science Foundation of Henan under Grant 202300410126Young Backbone Teachers in Henan Province (2018GGJS049)Henan Province Young Talent Lift Project (2020HYTP009)Program for Innovative Research Team in University of Henan Province (21IRTSTHNO15)Equipment Pre-research Joint Research Program of Ministry of Education (8091B032129)Training Program for Young Scholar of Henan Province for Colleges and Universities under Grand (2020GGJS172)Program for Science&Technology Innovation Talents in Universities of Henan Province under Grand (22HASTIT020)Henan Province Science Fund for Distinguished Young Scholars (222300420006).
文摘The huge increase in the communication network rate has made the application fields and scenarios for vehicular ad hoc networks more abundant and diversified and proposed more requirements for the efficiency and quality of data transmission.To improve the limited communication distance and poor communication quality of the Internet of Vehicles(IoV),an optimal intelligent routing algorithm is proposed in this paper.Combined multiweight decision algorithm with the greedy perimeter stateless routing protocol,designed and evaluated standardized function for link stability.Linear additive weighting is used to optimize link stability and distance to improve the packet delivery rate of the IoV.The blockchain system is used as the storage structure for relay data,and the smart contract incentive algorithm based on machine learning is used to encourage relay vehicles to provide more communication bandwidth for data packet transmission.The proposed scheme is simulated and analyzed under different scenarios and different parameters.The experimental results demonstrate that the proposed scheme can effectively reduce the packet loss rate and improve system performance.
基金supported by the National Science and Technology Major Projects under Grant No.2011ZX03001-007-03
文摘Opportunistic routing(OR) is an effective way to guarantee transmission reliability in wireless multi-hop networks.However,little research focuses on transmission efficiency.Thus,an analytical model based on open queuing network with Markov chains was proposed to evaluate the efficiency.By analyzing two typical ORs,we find duplicate transmission and collision avoidance overhead are the root reasons behind inefficiency.Therefore,a new scheme called dual priority cooperative opportunistic routing(DPCOR) was proposed.In DPCOR,forwarding candidates are configured with dual priority,which enables the network to classify forwarding candidates more effectively so as to reduce the back-off time and obtain more diversity gain.Theoretical analysis and simulation results show DPCOR achieves significant performance improvement with less time overhead compared with traditional routings and typical ORs.
基金supported by Korea Electric Power Corporation(Grant Number:R18XA02)。
文摘With the explosive advancements in wireless communications and digital electronics,some tiny devices,sensors,became a part of our daily life in numerous elds.Wireless sensor networks(WSNs)is composed of tiny sensor devices.WSNs have emerged as a key technology enabling the realization of the Internet of Things(IoT).In particular,the sensor-based revolution of WSN-based IoT has led to considerable technological growth in nearly all circles of our life such as smart cities,smart homes,smart healthcare,security applications,environmental monitoring,etc.However,the limitations of energy,communication range,and computational resources are bottlenecks to the widespread applications of this technology.In order to tackle these issues,in this paper,we propose an Energy-efcient Transmission Range Optimized Model for IoT(ETROMI),which can optimize the transmission range of the sensor nodes to curb the hot-spot problem occurring in multi-hop communication.In particular,we maximize the transmission range by employing linear programming to alleviate the sensor nodes’energy consumption and considerably enhance the network longevity compared to that achievable using state-of-the-art algorithms.Through extensive simulation results,we demonstrate the superiority of the proposed model.ETROMI is expected to be extensively used for various smart city,smart home,and smart healthcare applications in which the transmission range of the sensor nodes is a key concern.
基金Projects(2003CB314802) supported by the State Key Fundamental Research and Development Programof China project(90104001) supported by the National Natural Science Foundation of China
文摘In order to improve the data transmission reliability of mobile ad hoc network, a routing scheme called integrated forward error correction multipath routing protocol was proposed, which integrates the techniques of packet fragmenting and forward error correction encoding into multipath routing. The scheme works as follows: adding a certain redundancy into the original packets; fragmenting the resulting packets into exclusive blocks of the same size; encoding with the forward error correction technique, and then sending them to the destination node. When the receiving end receives a certain amount of information blocks, the original information will be recovered even with partial loss. The performance of the scheme was evaluated using OPNET modeler. The experimental results show that with the method the average transmission delay is decreased by 20% and the transmission reliability is increased by 30%.
文摘With the wide application of antibiotics in medicine and industry fields as well as the improvement of water quality detection technology,more and more reports show that antibiotics and antibiotic resistance genes(AGRs)were detected in various drinking water sources.The existence of these pollutants in water environment posed a great threat to human health.In this paper,the pollution status of antibiotics and transmission routes of antibiotic genes were introduced,and the characteristics and shortcomings of antibiotic treatment technology both at home and abroad were analyzed.Finally,suggestions and prospects for future antibiotic treatment technology were put forward.