Envelope analysis is an effective method for characterizing impulsive vibrations in wired condition monitoring(CM)systems. This paper depicts the implementation of envelope analysis on a wireless sensor node for obtai...Envelope analysis is an effective method for characterizing impulsive vibrations in wired condition monitoring(CM)systems. This paper depicts the implementation of envelope analysis on a wireless sensor node for obtaining a more convenient and reliable CM system. To maintain CM performances under the constraints of resources available in the cost effective Zigbee based wireless sensor network(WSN), a low cost cortex-M4 F microcontroller is employed as the core processor to implement the envelope analysis algorithm on the sensor node. The on-chip 12 bit analog-to-digital converter(ADC) working at 10 k Hz sampling rate is adopted to acquire vibration signals measured by a wide frequency band piezoelectric accelerometer. The data processing flow inside the processor is optimized to satisfy the large memory usage in implementing fast Fourier transform(FFT) and Hilbert transform(HT). Thus, the envelope spectrum can be computed from a data frame of 2048 points to achieve a frequency resolution acceptable for identifying the characteristic frequencies of different bearing faults. Experimental evaluation results show that the embedded envelope analysis algorithm can successfully diagnose the simulated bearing faults and the data transmission throughput can be reduced by at least 95% per frame compared with that of the raw data, allowing a large number of sensor nodes to be deployed in the network for real time monitoring.展开更多
Pure inertial navigation system(INS) has divergent localization errors after a long time. In order to compensate the disadvantage, wireless sensor network(WSN) associated with the INS was applied to estimate the mobil...Pure inertial navigation system(INS) has divergent localization errors after a long time. In order to compensate the disadvantage, wireless sensor network(WSN) associated with the INS was applied to estimate the mobile target positioning. Taking traditional Kalman filter(KF) as the framework, the system equation of KF was established by the INS and the observation equation of position errors was built by the WSN. Meanwhile, the observation equation of velocity errors was established by the velocity difference between the INS and WSN, then the covariance matrix of Kalman filter measurement noise was adjusted with fuzzy inference system(FIS), and the fuzzy adaptive Kalman filter(FAKF) based on the INS/WSN was proposed. The simulation results show that the FAKF method has better accuracy and robustness than KF and EKF methods and shows good adaptive capacity with time-varying system noise. Finally, experimental results further prove that FAKF has the fast convergence error, in comparison with KF and EKF methods.展开更多
As communication technology and smart manufacturing have developed, the industrial internet of things(IIo T)has gained considerable attention from academia and industry.Wireless sensor networks(WSNs) have many advanta...As communication technology and smart manufacturing have developed, the industrial internet of things(IIo T)has gained considerable attention from academia and industry.Wireless sensor networks(WSNs) have many advantages with broad applications in many areas including environmental monitoring, which makes it a very important part of IIo T. However,energy depletion and hardware malfunctions can lead to node failures in WSNs. The industrial environment can also impact the wireless channel transmission, leading to network reliability problems, even with tightly coupled control and data planes in traditional networks, which obviously also enhances network management cost and complexity. In this paper, we introduce a new software defined network(SDN), and modify this network to propose a framework called the improved software defined wireless sensor network(improved SD-WSN). This proposed framework can address the following issues. 1) For a large scale heterogeneous network, it solves the problem of network management and smooth merging of a WSN into IIo T. 2) The network coverage problem is solved which improves the network reliability. 3) The framework addresses node failure due to various problems, particularly related to energy consumption.Therefore, it is necessary to improve the reliability of wireless sensor networks, by developing certain schemes to reduce energy consumption and the delay time of network nodes under IIo T conditions. Experiments have shown that the improved approach significantly reduces the energy consumption of nodes and the delay time, thus improving the reliability of WSN.展开更多
Power is an important part of the energy industry,relating to national economy and people’s livelihood,and it is of great significance to ensure the security and stability in operation of power transmission and distr...Power is an important part of the energy industry,relating to national economy and people’s livelihood,and it is of great significance to ensure the security and stability in operation of power transmission and distribution system.Based on Wireless Sensor Network technology(WSN)and combined with the monitoring and operating requirements of power transmission and distribution system,this paper puts forward an application system for monitoring,inspection,security,and interactive service of layered power transmission and distribution system.Furthermore,this paper demonstrates the system verification projects in Wuxi,Jiangsu Province and Lianxiangyuan Community in Beijing,which have been widely used nationwide.展开更多
Wireless sensor network(WSN)nodes exchange information via wireless signals,whose power can attenuate at different levels according to the propagation environment.The branches and leaves of young apple trees are much ...Wireless sensor network(WSN)nodes exchange information via wireless signals,whose power can attenuate at different levels according to the propagation environment.The branches and leaves of young apple trees are much sparser than that of adult apple trees.Propagation rules such as propagation distance and attenuation rate are the parameters necessary to know before applying a WSN to a young apple orchard.Field tests were performed,and propagation distance and packet loss rate(PLR)were computed and compared under the two cases:a young apple orchard in fruit period and an open space to find the effect of the apple trees on radio propagation.A model of antenna height and propagation distance was created to forecast the extra path loss caused by the young trees.Validation experiments were performed in a different young apple orchard,and the validation results showed that 70% of R^(2) were higher than 0.7,while the smallest being 0.65;80% RMSE were smaller than 5.The new model was also compared with some classical models such as Cost 235,FITU,ITU-R,and Weissberger model,and the new model was proved to be the best.展开更多
Wireless sensor networks(WSN)gather information and sense information samples in a certain region and communicate these readings to a base station(BS).Energy efficiency is considered a major design issue in the WSNs,a...Wireless sensor networks(WSN)gather information and sense information samples in a certain region and communicate these readings to a base station(BS).Energy efficiency is considered a major design issue in the WSNs,and can be addressed using clustering and routing techniques.Information is sent from the source to the BS via routing procedures.However,these routing protocols must ensure that packets are delivered securely,guaranteeing that neither adversaries nor unauthentic individuals have access to the sent information.Secure data transfer is intended to protect the data from illegal access,damage,or disruption.Thus,in the proposed model,secure data transmission is developed in an energy-effective manner.A low-energy adaptive clustering hierarchy(LEACH)is developed to efficiently transfer the data.For the intrusion detection systems(IDS),Fuzzy logic and artificial neural networks(ANNs)are proposed.Initially,the nodes were randomly placed in the network and initialized to gather information.To ensure fair energy dissipation between the nodes,LEACH randomly chooses cluster heads(CHs)and allocates this role to the various nodes based on a round-robin management mechanism.The intrusion-detection procedure was then utilized to determine whether intruders were present in the network.Within the WSN,a Fuzzy interference rule was utilized to distinguish the malicious nodes from legal nodes.Subsequently,an ANN was employed to distinguish the harmful nodes from suspicious nodes.The effectiveness of the proposed approach was validated using metrics that attained 97%accuracy,97%specificity,and 97%sensitivity of 95%.Thus,it was proved that the LEACH and Fuzzy-based IDS approaches are the best choices for securing data transmission in an energy-efficient manner.展开更多
Wireless Sensor Network(WSN)is a distributed sensor network composed a large number of nodes with low cost,low performance and self-management.The special structure of WSN brings both convenience and vulnerability.For...Wireless Sensor Network(WSN)is a distributed sensor network composed a large number of nodes with low cost,low performance and self-management.The special structure of WSN brings both convenience and vulnerability.For example,a malicious participant can launch attacks by capturing a physical device.Therefore,node authentication that can resist malicious attacks is very important to network security.Recently,blockchain technology has shown the potential to enhance the security of the Internet of Things(IoT).In this paper,we propose a Blockchain-empowered Authentication Scheme(BAS)for WSN.In our scheme,all nodes are managed by utilizing the identity information stored on the blockchain.Besides,the simulation experiment about worm detection is executed on BAS,and the security is evaluated from detection and infection rate.The experiment results indicate that the proposed scheme can effectively inhibit the spread and infection of worms in the network.展开更多
The applications of wireless sensor network(WSN)exhibits a significant rise in recent days since it is enveloped with various advantageous benefits.In the medical field,the emergence of WSN has created marvelous chang...The applications of wireless sensor network(WSN)exhibits a significant rise in recent days since it is enveloped with various advantageous benefits.In the medical field,the emergence of WSN has created marvelous changes in monitoring the health conditions of the patients and so it is attracted by doctors and physicians.WSN assists in providing health care services without any delay and so it plays predominant role in saving the life of human.The data of different persons,time,places and networks have been linked with certain devices,which are collectively known as Internet of Things(IOT);it is regarded as the essential requirement of people in recent days.In the health care monitoring system,IOT plays a magnificent role,which has produced the real time monitoring of patient’s condition.However the medical data transmission is accomplished quickly with high security by the routing and key management.When the data from the digital record system(cloud)is accessed by the patients or doctors,the medical data is transferred quickly through WSN by performing routing.The Probabilistic Neural Network(PNN)is utilized,which authenticates the shortest path to reach the destination and its performance is identified by comparing it with the Dynamic Source Routing(DSR)protocol and Energy aware and Stable Routing(ESR)protocol.While performing routing,the secured transmission is achieved by key management,for which the Diffie Hellman key exchange is utilized,which performs encryption and decryption to secure the medical data.This enables the quick and secured transmission of data from source to destination with improved throughput and delivery ratio.展开更多
Unmanned aerial vehicles(UAVs) are advantageous for data collection in wireless sensor networks(WSNs) due to its low cost of use,flexible deployment,controllable mobility,etc. However,how to cope with the inherent iss...Unmanned aerial vehicles(UAVs) are advantageous for data collection in wireless sensor networks(WSNs) due to its low cost of use,flexible deployment,controllable mobility,etc. However,how to cope with the inherent issues of energy limitation and data security in the WSNs is challenging in such an application paradigm. To this end,based on the framework of physical layer security,an optimization problem for maximizing secrecy energy efficiency(EE) of data collection is formulated,which focuses on optimizing the UAV’s positions and the sensors’ transmit power. To overcome the difficulties in solving the optimization problem,the methods of fractional programming and successive convex approximation are then adopted to gradually transform the original problem into a series of tractable subproblems which are solved in an iterative manner. As shown in simulation results,by the joint designs in the spatial domain of UAV and the power domain of sensors,the proposed algorithm achieves a significant improvement of secrecy EE and rate.展开更多
Time synchronization is one of the base techniques in wireless sensor networks(WSNs).This paper proposes a novel time synchronization protocol which is a robust consensusbased algorithm in the existence of transmissio...Time synchronization is one of the base techniques in wireless sensor networks(WSNs).This paper proposes a novel time synchronization protocol which is a robust consensusbased algorithm in the existence of transmission delay and packet loss.It compensates for transmission delay and packet loss firstly,and then,estimates clock skew and clock offset in two steps.Simulation and experiment results show that the proposed protocol can keep synchronization error below 2μs in the grid network of 10 nodes or the random network of 90 nodes.Moreover,the synchronization accuracy in the proposed protocol can keep constant when the WSN works up to a month.展开更多
In wireless sensor network(WSN),the gateways which are placed far away from the base station(BS)forward the collected data to the BS through the gateways which are nearer to the BS.This leads to more energy consumptio...In wireless sensor network(WSN),the gateways which are placed far away from the base station(BS)forward the collected data to the BS through the gateways which are nearer to the BS.This leads to more energy consumption because the gateways nearer to the BS manages heavy traffic load.So,to over-come this issue,loads around the gateways are to be balanced by presenting energy efficient clustering approach.Besides,to enhance the lifetime of the net-work,optimal routing path is to be established between the source node and BS.For energy efficient load balancing and routing,multi objective based beetle swarm optimization(BSO)algorithm is presented in this paper.Using this algo-rithm,optimal clustering and routing are performed depend on the objective func-tions routingfitness and clusteringfitness.This approach leads to decrease the power consumption.Simulation results show that the performance of the pro-posed BSO based clustering and routing scheme attains better results than that of the existing algorithms in terms of energy consumption,delivery ratio,through-put and network lifetime.Namely,the proposed scheme increases throughput to 72%and network lifetime to 37%as well as it reduces delay to 37%than the existing optimization algorithms based clustering and routing schemes.展开更多
Energy efficiency is an important criterion for routing algorithms in the wireless sensor network. Cooperative routing can reduce energy consumption effectively stemming from its diversity gain advantage. To solve the...Energy efficiency is an important criterion for routing algorithms in the wireless sensor network. Cooperative routing can reduce energy consumption effectively stemming from its diversity gain advantage. To solve the energy consumption problem and maximize the network lifetime, this paper proposes a Virtual Multiple Input Multiple Output based Cooperative Routing algorithm(VMIMOCR). VMIMOCR chooses cooperative relay nodes based on Virtual Multiple Input Multiple Output Model, and balances energy consumption by reasonable power allocation among transmitters, and decides the forwarding path finally. The experimental results show that VMIMOCR can improve network lifetime from 37% to 348% in the medium node density, compared with existing routing algorithms.展开更多
Over the last decades,geo-structures are experiencing a rapid development in China.The potential risks inherent in the huge amount of construction and asset operation projects in China were well managed in the major p...Over the last decades,geo-structures are experiencing a rapid development in China.The potential risks inherent in the huge amount of construction and asset operation projects in China were well managed in the major project,i.e.the project of Shanghai Yangtze tunnel in 2002.Since then,risk assessment of geostructures has been gradually developed from a qualitative manner to a quantitative manner.However,the current practices of risk management have been paid considerable attention to the assessment,but little on risk control.As a result,the responses to risks occurrences after a comprehensive assessment are basically too late.In this paper,a smart system for risk sensing incorporating the wireless sensor network(WSN) on-site visualization techniques and the resilience-based repair strategy was proposed.The merit of this system is the real-time monitoring for geo-structural performance and dynamic pre-warning for safety of on-site workers.The sectional convergence,joint opening,and seepage of segmental lining of shield tunnel were monitored by the micro-electro-mechanical systems(MEMS) based sensors.The light emitting diode(LED) coupling with the above WSN system was used to indicate different risk levels on site.By sensing the risks and telling the risks in real time,the geo-risks could be controlled and the safety of geo-structures could be assured to a certain degree.Finally,a resilience-based analysis model was proposed for designing the repair strategy by using the measured data from the WSN system.The application and efficiency of this system have been validated by two cases including Shanghai metro tunnel and underwater road tunnel.展开更多
Fire disasters and the deterioration of tunnel structures are major concerns for tunnel operation and maintenance.Traditional wired monitoring systems have many drawbacks in terms of installation time,overall cost,and...Fire disasters and the deterioration of tunnel structures are major concerns for tunnel operation and maintenance.Traditional wired monitoring systems have many drawbacks in terms of installation time,overall cost,and flexibility in tunnel environments.In recent years,there has been growing interest in the use of wireless sensor networks(WSNs)for the monitoring of various structural monitoring applications.This paper evaluated the feasibility of applying a WSN in the monitoring of tunnels.The monitoring requirements of tunnels under explosion and combustion fire scenarios are analyzed using numerical simulation,and the maximum possible distance for temperature sensors is derived.The displacement monitoring of tunnels using an inclinometer is investigated.It is recommended that the inclinometer should be installed in the 1/4 span of the tunnel structure.The maximum wireless transmission distances in both outdoor and tunnel environments were examined.The influences of surface materials and sensor node locations on the data transmission distance in tunnel environments were also investigated.The experimental results show that the data loss in tunnel environments is approximately three times that in outdoor environments.Surface material has a considerable influence on the transmission distance of radio signals.The distance is 25~28 m for a raw concrete surface,20 m for a brick surface,and 36 m for a terrazzo surface.The transmission distances along the middle of quarter points are approximately 0.9D(D is the transmission distance in the center of the tunnel),and the relative error is less than±3%.The transmission distances at different locations along the bottom exhibit significant differences,decreasing from the middle to the comer point,with distances of approximately 0.8D at the quarter points and minimum distances of approximately 0.55D at the comer points.展开更多
Aiming at the problem of poor observability of measurement information in the loosely-coupled integration of the inertial navigation system （INS） and the wireless sensor network （WSN）, this paper presents a tightl...Aiming at the problem of poor observability of measurement information in the loosely-coupled integration of the inertial navigation system （INS） and the wireless sensor network （WSN）, this paper presents a tightly-coupled integration based on the Kalman filter （KF）. When the WSN is available, the difference between the distances from the blind node（BN） to the reference nodes （RNs） measured by the INS and those measured by the WSN are used as measurement information for the KF due to its better observability and independence, which can effectively improve the accuracy of the KF. Simulations show that the proposed approach reduces the mean error of the position by about 50% compared with loosely-coupled integration, while the mean error of the velocity is a little higher than that of loosely-coupled integration.展开更多
To slove the problems of constrained energy and unbalanced load of wireless sensor network(WSN)nodes,a multipath load balancing routing algorithm based on neighborhood subspace cooperation is proposed.The algorithm ad...To slove the problems of constrained energy and unbalanced load of wireless sensor network(WSN)nodes,a multipath load balancing routing algorithm based on neighborhood subspace cooperation is proposed.The algorithm adopts the improved particle swarm optimization(PSO)algorithm,takes the shortest distance and minimum energy consumption as optimization target and divides the nodes in one-hop neighborhood near the base station area into different regions.Furthermore,the algorithm designs a fitness function to find the best node in each region as a relay node and forward the data in parallel through the different paths of the relay nodes.The simulation results show that the proposed algorithm can reduce energy consumption and average end-to-end delay,balance network load and prolong network lifetime effectively.展开更多
感知节点的定位是无线传感网应用的基础。现有的静态定位算法无法应用于动态传感网。针对一类目标节点移动而锚节点静止的传感网应用,提出了一种RRMCL(RSSI Rank Monte Carlo Localization)定位算法。该算法以蒙特卡罗算法为基础,利用RS...感知节点的定位是无线传感网应用的基础。现有的静态定位算法无法应用于动态传感网。针对一类目标节点移动而锚节点静止的传感网应用,提出了一种RRMCL(RSSI Rank Monte Carlo Localization)定位算法。该算法以蒙特卡罗算法为基础,利用RSSI(Received Signal Strength Indication)值与距离的单调递减关系划分通信域,减少采样区域大小。为了避免锚节点共线出现定位失效的情况,引入共线影响角度,提出了一种约束策略。仿真结果表明,提出的RRMCL与现有的MCL和MCB定位算法相比,能有效缩小采样区域,提高了定位精度和速度。展开更多
In this work,a novel performance analysis method for evaluating the robustness of emerging power distribution networks(PDNs),which involve deployable renewable energy sources,is proposed.This is realized with the aid ...In this work,a novel performance analysis method for evaluating the robustness of emerging power distribution networks(PDNs),which involve deployable renewable energy sources,is proposed.This is realized with the aid of the outage probability(OP)criterion in the context of cooperative communications,which is widely considered in modern wireless communication systems.The main usefulness of this method is that it allows the involved components to communicate to each-other by means of a robust and flexible wireless sensor network architecture.In this context,any conventional medium voltage(MV)bus of the PDN is represented as a wireless relay node where data signals gathered from each MV bus can be forwarded reliably to a control station for the subsequent processing.The received signals at wireless nodes are decoded and then forwarded to ensure minimal errors and maximal robustness at the receiving site.The considered OP analysis denotes the probability that the power of a received information signal drops below a pre-defined threshold which satisfies the acceptable Quality of Service requirements of a reliable signal reception.To this end,simple closed-form expressions are proposed for the OP of a regenerative cooperative-based PDN in the presence of various multipath fading effects,which degrade information signals during wireless transmission.The offered results are rather simple and provide meaningful insights for the design and deployment of smart grid systems.展开更多
Long-term and stable wireless sensor network(WSN)node′s operation should be included in large-scale unattended industrial production.Here a kind of WSN node applied to multiple large-scale industrial productions is d...Long-term and stable wireless sensor network(WSN)node′s operation should be included in large-scale unattended industrial production.Here a kind of WSN node applied to multiple large-scale industrial productions is designed by analyzing WSN technologies and its multiple applications,and studying the node′s practical operating environment.A new method for applying image-recognition technology realized initially by using plenty of expensive sensors is proposed to analyze video data.When the node is applied in such situations as unattended operation and field monitoring,solar power generator is adopted to provide energy for the node system by charging a battery.The communication between WSN and background monitoring center is realized by GPRS module,and the operation of node is managed by transplanting μC/OS-Ⅱ into the ARM7 kernel microprocessor.The results show that the WSN node designed in this paper can be applied to control information transmission of wild and unattended large-scale industrial applications with stable and reliable performance.展开更多
A Wireless Sensor Network(WSNs) fault-tolerant protocol is proposed in this paper.By setting up a robust cluster topology,the fault-tolerant algorithm can search any faulty node in the path and revise the path further...A Wireless Sensor Network(WSNs) fault-tolerant protocol is proposed in this paper.By setting up a robust cluster topology,the fault-tolerant algorithm can search any faulty node in the path and revise the path furthermore.Once the cluster head fails,it will be substituted by other alternative cluster heads with the lowest cost,and the path will be re-established.Experiments show that this algorithm can not only locate the faulty nodes in the path accurately,shield the influence of the error node in clusters,but also reduce the retransmission times of relevant data caused by error node.Therefore,the proposed algorithm is effective and sufficient enough to resist malicious attack and node losses.In energy consumption aspect,compared with others,the proposed algorithm has a more advantage in energy conservation.展开更多
文摘Envelope analysis is an effective method for characterizing impulsive vibrations in wired condition monitoring(CM)systems. This paper depicts the implementation of envelope analysis on a wireless sensor node for obtaining a more convenient and reliable CM system. To maintain CM performances under the constraints of resources available in the cost effective Zigbee based wireless sensor network(WSN), a low cost cortex-M4 F microcontroller is employed as the core processor to implement the envelope analysis algorithm on the sensor node. The on-chip 12 bit analog-to-digital converter(ADC) working at 10 k Hz sampling rate is adopted to acquire vibration signals measured by a wide frequency band piezoelectric accelerometer. The data processing flow inside the processor is optimized to satisfy the large memory usage in implementing fast Fourier transform(FFT) and Hilbert transform(HT). Thus, the envelope spectrum can be computed from a data frame of 2048 points to achieve a frequency resolution acceptable for identifying the characteristic frequencies of different bearing faults. Experimental evaluation results show that the embedded envelope analysis algorithm can successfully diagnose the simulated bearing faults and the data transmission throughput can be reduced by at least 95% per frame compared with that of the raw data, allowing a large number of sensor nodes to be deployed in the network for real time monitoring.
基金Project(2013AA06A411)supported by the National High Technology Research and Development Program of ChinaProject(CXZZ14_1374)supported by the Graduate Education Innovation Program of Jiangsu Province,ChinaProject supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions,China
文摘Pure inertial navigation system(INS) has divergent localization errors after a long time. In order to compensate the disadvantage, wireless sensor network(WSN) associated with the INS was applied to estimate the mobile target positioning. Taking traditional Kalman filter(KF) as the framework, the system equation of KF was established by the INS and the observation equation of position errors was built by the WSN. Meanwhile, the observation equation of velocity errors was established by the velocity difference between the INS and WSN, then the covariance matrix of Kalman filter measurement noise was adjusted with fuzzy inference system(FIS), and the fuzzy adaptive Kalman filter(FAKF) based on the INS/WSN was proposed. The simulation results show that the FAKF method has better accuracy and robustness than KF and EKF methods and shows good adaptive capacity with time-varying system noise. Finally, experimental results further prove that FAKF has the fast convergence error, in comparison with KF and EKF methods.
基金supported by the National Natural Science Foundation of China(61571336)the Science and Technology Project of Henan Province in China(172102210081)the Independent Innovation Research Foundation of Wuhan University of Technology(2016-JL-036)
文摘As communication technology and smart manufacturing have developed, the industrial internet of things(IIo T)has gained considerable attention from academia and industry.Wireless sensor networks(WSNs) have many advantages with broad applications in many areas including environmental monitoring, which makes it a very important part of IIo T. However,energy depletion and hardware malfunctions can lead to node failures in WSNs. The industrial environment can also impact the wireless channel transmission, leading to network reliability problems, even with tightly coupled control and data planes in traditional networks, which obviously also enhances network management cost and complexity. In this paper, we introduce a new software defined network(SDN), and modify this network to propose a framework called the improved software defined wireless sensor network(improved SD-WSN). This proposed framework can address the following issues. 1) For a large scale heterogeneous network, it solves the problem of network management and smooth merging of a WSN into IIo T. 2) The network coverage problem is solved which improves the network reliability. 3) The framework addresses node failure due to various problems, particularly related to energy consumption.Therefore, it is necessary to improve the reliability of wireless sensor networks, by developing certain schemes to reduce energy consumption and the delay time of network nodes under IIo T conditions. Experiments have shown that the improved approach significantly reduces the energy consumption of nodes and the delay time, thus improving the reliability of WSN.
基金The project was supported by the National Science and Technology Major Project of the Ministry of Science and Technology of the People’s Republic of China.
文摘Power is an important part of the energy industry,relating to national economy and people’s livelihood,and it is of great significance to ensure the security and stability in operation of power transmission and distribution system.Based on Wireless Sensor Network technology(WSN)and combined with the monitoring and operating requirements of power transmission and distribution system,this paper puts forward an application system for monitoring,inspection,security,and interactive service of layered power transmission and distribution system.Furthermore,this paper demonstrates the system verification projects in Wuxi,Jiangsu Province and Lianxiangyuan Community in Beijing,which have been widely used nationwide.
基金financially supported by the National High Technology and Development Program of China(863):Model-based digital management platform for orchard and rape plants(2013AA102405).
文摘Wireless sensor network(WSN)nodes exchange information via wireless signals,whose power can attenuate at different levels according to the propagation environment.The branches and leaves of young apple trees are much sparser than that of adult apple trees.Propagation rules such as propagation distance and attenuation rate are the parameters necessary to know before applying a WSN to a young apple orchard.Field tests were performed,and propagation distance and packet loss rate(PLR)were computed and compared under the two cases:a young apple orchard in fruit period and an open space to find the effect of the apple trees on radio propagation.A model of antenna height and propagation distance was created to forecast the extra path loss caused by the young trees.Validation experiments were performed in a different young apple orchard,and the validation results showed that 70% of R^(2) were higher than 0.7,while the smallest being 0.65;80% RMSE were smaller than 5.The new model was also compared with some classical models such as Cost 235,FITU,ITU-R,and Weissberger model,and the new model was proved to be the best.
文摘Wireless sensor networks(WSN)gather information and sense information samples in a certain region and communicate these readings to a base station(BS).Energy efficiency is considered a major design issue in the WSNs,and can be addressed using clustering and routing techniques.Information is sent from the source to the BS via routing procedures.However,these routing protocols must ensure that packets are delivered securely,guaranteeing that neither adversaries nor unauthentic individuals have access to the sent information.Secure data transfer is intended to protect the data from illegal access,damage,or disruption.Thus,in the proposed model,secure data transmission is developed in an energy-effective manner.A low-energy adaptive clustering hierarchy(LEACH)is developed to efficiently transfer the data.For the intrusion detection systems(IDS),Fuzzy logic and artificial neural networks(ANNs)are proposed.Initially,the nodes were randomly placed in the network and initialized to gather information.To ensure fair energy dissipation between the nodes,LEACH randomly chooses cluster heads(CHs)and allocates this role to the various nodes based on a round-robin management mechanism.The intrusion-detection procedure was then utilized to determine whether intruders were present in the network.Within the WSN,a Fuzzy interference rule was utilized to distinguish the malicious nodes from legal nodes.Subsequently,an ANN was employed to distinguish the harmful nodes from suspicious nodes.The effectiveness of the proposed approach was validated using metrics that attained 97%accuracy,97%specificity,and 97%sensitivity of 95%.Thus,it was proved that the LEACH and Fuzzy-based IDS approaches are the best choices for securing data transmission in an energy-efficient manner.
基金supported by the Natural Science Foundation under Grant No.61962009Major Scientific and Technological Special Project of Guizhou Province under Grant No.20183001Foundation of Guizhou Provincial Key Laboratory of Public Big Data under Grant No.2018BDKFJJ003,2018BDKFJJ005 and 2019BDKFJJ009.
文摘Wireless Sensor Network(WSN)is a distributed sensor network composed a large number of nodes with low cost,low performance and self-management.The special structure of WSN brings both convenience and vulnerability.For example,a malicious participant can launch attacks by capturing a physical device.Therefore,node authentication that can resist malicious attacks is very important to network security.Recently,blockchain technology has shown the potential to enhance the security of the Internet of Things(IoT).In this paper,we propose a Blockchain-empowered Authentication Scheme(BAS)for WSN.In our scheme,all nodes are managed by utilizing the identity information stored on the blockchain.Besides,the simulation experiment about worm detection is executed on BAS,and the security is evaluated from detection and infection rate.The experiment results indicate that the proposed scheme can effectively inhibit the spread and infection of worms in the network.
文摘The applications of wireless sensor network(WSN)exhibits a significant rise in recent days since it is enveloped with various advantageous benefits.In the medical field,the emergence of WSN has created marvelous changes in monitoring the health conditions of the patients and so it is attracted by doctors and physicians.WSN assists in providing health care services without any delay and so it plays predominant role in saving the life of human.The data of different persons,time,places and networks have been linked with certain devices,which are collectively known as Internet of Things(IOT);it is regarded as the essential requirement of people in recent days.In the health care monitoring system,IOT plays a magnificent role,which has produced the real time monitoring of patient’s condition.However the medical data transmission is accomplished quickly with high security by the routing and key management.When the data from the digital record system(cloud)is accessed by the patients or doctors,the medical data is transferred quickly through WSN by performing routing.The Probabilistic Neural Network(PNN)is utilized,which authenticates the shortest path to reach the destination and its performance is identified by comparing it with the Dynamic Source Routing(DSR)protocol and Energy aware and Stable Routing(ESR)protocol.While performing routing,the secured transmission is achieved by key management,for which the Diffie Hellman key exchange is utilized,which performs encryption and decryption to secure the medical data.This enables the quick and secured transmission of data from source to destination with improved throughput and delivery ratio.
基金Supported by the National Natural Science Foundation of China(No.61871401).
文摘Unmanned aerial vehicles(UAVs) are advantageous for data collection in wireless sensor networks(WSNs) due to its low cost of use,flexible deployment,controllable mobility,etc. However,how to cope with the inherent issues of energy limitation and data security in the WSNs is challenging in such an application paradigm. To this end,based on the framework of physical layer security,an optimization problem for maximizing secrecy energy efficiency(EE) of data collection is formulated,which focuses on optimizing the UAV’s positions and the sensors’ transmit power. To overcome the difficulties in solving the optimization problem,the methods of fractional programming and successive convex approximation are then adopted to gradually transform the original problem into a series of tractable subproblems which are solved in an iterative manner. As shown in simulation results,by the joint designs in the spatial domain of UAV and the power domain of sensors,the proposed algorithm achieves a significant improvement of secrecy EE and rate.
文摘Time synchronization is one of the base techniques in wireless sensor networks(WSNs).This paper proposes a novel time synchronization protocol which is a robust consensusbased algorithm in the existence of transmission delay and packet loss.It compensates for transmission delay and packet loss firstly,and then,estimates clock skew and clock offset in two steps.Simulation and experiment results show that the proposed protocol can keep synchronization error below 2μs in the grid network of 10 nodes or the random network of 90 nodes.Moreover,the synchronization accuracy in the proposed protocol can keep constant when the WSN works up to a month.
文摘In wireless sensor network(WSN),the gateways which are placed far away from the base station(BS)forward the collected data to the BS through the gateways which are nearer to the BS.This leads to more energy consumption because the gateways nearer to the BS manages heavy traffic load.So,to over-come this issue,loads around the gateways are to be balanced by presenting energy efficient clustering approach.Besides,to enhance the lifetime of the net-work,optimal routing path is to be established between the source node and BS.For energy efficient load balancing and routing,multi objective based beetle swarm optimization(BSO)algorithm is presented in this paper.Using this algo-rithm,optimal clustering and routing are performed depend on the objective func-tions routingfitness and clusteringfitness.This approach leads to decrease the power consumption.Simulation results show that the performance of the pro-posed BSO based clustering and routing scheme attains better results than that of the existing algorithms in terms of energy consumption,delivery ratio,through-put and network lifetime.Namely,the proposed scheme increases throughput to 72%and network lifetime to 37%as well as it reduces delay to 37%than the existing optimization algorithms based clustering and routing schemes.
基金supported by the National Basic Research Program of China (973 program) (Grant No.2012CB315805)the National Natural Science Foundation of China (Grant No.61472130 and 61572184)
文摘Energy efficiency is an important criterion for routing algorithms in the wireless sensor network. Cooperative routing can reduce energy consumption effectively stemming from its diversity gain advantage. To solve the energy consumption problem and maximize the network lifetime, this paper proposes a Virtual Multiple Input Multiple Output based Cooperative Routing algorithm(VMIMOCR). VMIMOCR chooses cooperative relay nodes based on Virtual Multiple Input Multiple Output Model, and balances energy consumption by reasonable power allocation among transmitters, and decides the forwarding path finally. The experimental results show that VMIMOCR can improve network lifetime from 37% to 348% in the medium node density, compared with existing routing algorithms.
基金supported by the National Natural Science Foundation of China(Grant Nos.51278381,51538009 and 51608380)the International Research Cooperation Project of Shanghai Science and Technology Committee(Grant No.15220721600)the Peak Discipline Construction on Civil Engineering of Shanghai Project
文摘Over the last decades,geo-structures are experiencing a rapid development in China.The potential risks inherent in the huge amount of construction and asset operation projects in China were well managed in the major project,i.e.the project of Shanghai Yangtze tunnel in 2002.Since then,risk assessment of geostructures has been gradually developed from a qualitative manner to a quantitative manner.However,the current practices of risk management have been paid considerable attention to the assessment,but little on risk control.As a result,the responses to risks occurrences after a comprehensive assessment are basically too late.In this paper,a smart system for risk sensing incorporating the wireless sensor network(WSN) on-site visualization techniques and the resilience-based repair strategy was proposed.The merit of this system is the real-time monitoring for geo-structural performance and dynamic pre-warning for safety of on-site workers.The sectional convergence,joint opening,and seepage of segmental lining of shield tunnel were monitored by the micro-electro-mechanical systems(MEMS) based sensors.The light emitting diode(LED) coupling with the above WSN system was used to indicate different risk levels on site.By sensing the risks and telling the risks in real time,the geo-risks could be controlled and the safety of geo-structures could be assured to a certain degree.Finally,a resilience-based analysis model was proposed for designing the repair strategy by using the measured data from the WSN system.The application and efficiency of this system have been validated by two cases including Shanghai metro tunnel and underwater road tunnel.
基金This research was supported by the National Basic Research Program of China(973 Program:2011CB013800)Changjiang Scholars and Innovative Research Team in University(PCSIRT,IRT1029)and the Fundamental Research Funds for the Central Universities.These financial supports are gratefully acknowledged.
文摘Fire disasters and the deterioration of tunnel structures are major concerns for tunnel operation and maintenance.Traditional wired monitoring systems have many drawbacks in terms of installation time,overall cost,and flexibility in tunnel environments.In recent years,there has been growing interest in the use of wireless sensor networks(WSNs)for the monitoring of various structural monitoring applications.This paper evaluated the feasibility of applying a WSN in the monitoring of tunnels.The monitoring requirements of tunnels under explosion and combustion fire scenarios are analyzed using numerical simulation,and the maximum possible distance for temperature sensors is derived.The displacement monitoring of tunnels using an inclinometer is investigated.It is recommended that the inclinometer should be installed in the 1/4 span of the tunnel structure.The maximum wireless transmission distances in both outdoor and tunnel environments were examined.The influences of surface materials and sensor node locations on the data transmission distance in tunnel environments were also investigated.The experimental results show that the data loss in tunnel environments is approximately three times that in outdoor environments.Surface material has a considerable influence on the transmission distance of radio signals.The distance is 25~28 m for a raw concrete surface,20 m for a brick surface,and 36 m for a terrazzo surface.The transmission distances along the middle of quarter points are approximately 0.9D(D is the transmission distance in the center of the tunnel),and the relative error is less than±3%.The transmission distances at different locations along the bottom exhibit significant differences,decreasing from the middle to the comer point,with distances of approximately 0.8D at the quarter points and minimum distances of approximately 0.55D at the comer points.
基金The National Basic Research Program of China(973 Program)(No.2009CB724002)the National Natural Science Foundation of China(No.50975049)+3 种基金the Specialized Research Fund for the Doctoral Program of Higher Education of China(No.20110092110039)the Aviation Science Foundation(No.20090869008)the Six Peak Talents Foundation in Jiangsu Province(No.2008143)Program of Scientific Innovation Research of College Graduate in Jiangsu Province(No.CXLX_0101)
文摘Aiming at the problem of poor observability of measurement information in the loosely-coupled integration of the inertial navigation system （INS） and the wireless sensor network （WSN）, this paper presents a tightly-coupled integration based on the Kalman filter （KF）. When the WSN is available, the difference between the distances from the blind node（BN） to the reference nodes （RNs） measured by the INS and those measured by the WSN are used as measurement information for the KF due to its better observability and independence, which can effectively improve the accuracy of the KF. Simulations show that the proposed approach reduces the mean error of the position by about 50% compared with loosely-coupled integration, while the mean error of the velocity is a little higher than that of loosely-coupled integration.
基金National Natural Science Foundation of China(No.11461038)Science and Technology Plan of Gansu Province(No.144NKCA040)
文摘To slove the problems of constrained energy and unbalanced load of wireless sensor network(WSN)nodes,a multipath load balancing routing algorithm based on neighborhood subspace cooperation is proposed.The algorithm adopts the improved particle swarm optimization(PSO)algorithm,takes the shortest distance and minimum energy consumption as optimization target and divides the nodes in one-hop neighborhood near the base station area into different regions.Furthermore,the algorithm designs a fitness function to find the best node in each region as a relay node and forward the data in parallel through the different paths of the relay nodes.The simulation results show that the proposed algorithm can reduce energy consumption and average end-to-end delay,balance network load and prolong network lifetime effectively.
文摘感知节点的定位是无线传感网应用的基础。现有的静态定位算法无法应用于动态传感网。针对一类目标节点移动而锚节点静止的传感网应用,提出了一种RRMCL(RSSI Rank Monte Carlo Localization)定位算法。该算法以蒙特卡罗算法为基础,利用RSSI(Received Signal Strength Indication)值与距离的单调递减关系划分通信域,减少采样区域大小。为了避免锚节点共线出现定位失效的情况,引入共线影响角度,提出了一种约束策略。仿真结果表明,提出的RRMCL与现有的MCL和MCB定位算法相比,能有效缩小采样区域,提高了定位精度和速度。
基金This work was supported by the Research Program DGRES(MIS 380360)within the Research Activity ARCHIMEDES III,funded by the NSRF 2007-2013,Greece.
文摘In this work,a novel performance analysis method for evaluating the robustness of emerging power distribution networks(PDNs),which involve deployable renewable energy sources,is proposed.This is realized with the aid of the outage probability(OP)criterion in the context of cooperative communications,which is widely considered in modern wireless communication systems.The main usefulness of this method is that it allows the involved components to communicate to each-other by means of a robust and flexible wireless sensor network architecture.In this context,any conventional medium voltage(MV)bus of the PDN is represented as a wireless relay node where data signals gathered from each MV bus can be forwarded reliably to a control station for the subsequent processing.The received signals at wireless nodes are decoded and then forwarded to ensure minimal errors and maximal robustness at the receiving site.The considered OP analysis denotes the probability that the power of a received information signal drops below a pre-defined threshold which satisfies the acceptable Quality of Service requirements of a reliable signal reception.To this end,simple closed-form expressions are proposed for the OP of a regenerative cooperative-based PDN in the presence of various multipath fading effects,which degrade information signals during wireless transmission.The offered results are rather simple and provide meaningful insights for the design and deployment of smart grid systems.
基金supported by the Cooperative Innovation Fund of Industry-Study-Research of Jiangsu Province (No.BY2013074-03)the Key Laboratory of Underwater Acoustic Communication and Marine Information Technology Ministry of Education+1 种基金the Natural Science Foundation of Changzhou Institute of Technology (No.E3-6107-15037)the Student Innovation Training Program of Jiangsu Province(No.201611055019Y)
文摘Long-term and stable wireless sensor network(WSN)node′s operation should be included in large-scale unattended industrial production.Here a kind of WSN node applied to multiple large-scale industrial productions is designed by analyzing WSN technologies and its multiple applications,and studying the node′s practical operating environment.A new method for applying image-recognition technology realized initially by using plenty of expensive sensors is proposed to analyze video data.When the node is applied in such situations as unattended operation and field monitoring,solar power generator is adopted to provide energy for the node system by charging a battery.The communication between WSN and background monitoring center is realized by GPRS module,and the operation of node is managed by transplanting μC/OS-Ⅱ into the ARM7 kernel microprocessor.The results show that the WSN node designed in this paper can be applied to control information transmission of wild and unattended large-scale industrial applications with stable and reliable performance.
基金Supported by the National Natural Science Foundation of China (No.60703101)
文摘A Wireless Sensor Network(WSNs) fault-tolerant protocol is proposed in this paper.By setting up a robust cluster topology,the fault-tolerant algorithm can search any faulty node in the path and revise the path furthermore.Once the cluster head fails,it will be substituted by other alternative cluster heads with the lowest cost,and the path will be re-established.Experiments show that this algorithm can not only locate the faulty nodes in the path accurately,shield the influence of the error node in clusters,but also reduce the retransmission times of relevant data caused by error node.Therefore,the proposed algorithm is effective and sufficient enough to resist malicious attack and node losses.In energy consumption aspect,compared with others,the proposed algorithm has a more advantage in energy conservation.
