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Event-Based Anomaly Detection for Non-Public Industrial Communication Protocols in SDN-Based Control Systems 被引量:4
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作者 Ming Wan Jiangyuan Yao +1 位作者 Yuan Jing Xi Jin 《Computers, Materials & Continua》 SCIE EI 2018年第6期447-463,共17页
As the main communication mediums in industrial control networks,industrial communication protocols are always vulnerable to extreme exploitations,and it is very difficult to take protective measures due to their seri... As the main communication mediums in industrial control networks,industrial communication protocols are always vulnerable to extreme exploitations,and it is very difficult to take protective measures due to their serious privacy.Based on the SDN(Software Defined Network)technology,this paper proposes a novel event-based anomaly detection approach to identify misbehaviors using non-public industrial communication protocols,and this approach can be installed in SDN switches as a security software appliance in SDN-based control systems.Furthermore,aiming at the unknown protocol specification and message format,this approach first restructures the industrial communication sessions and merges the payloads from industrial communication packets.After that,the feature selection and event sequence extraction can be carried out by using the N-gram model and K-means algorithm.Based on the obtained event sequences,this approach finally trains an event-based HMM(Hidden Markov Model)to identify aberrant industrial communication behaviors.Experimental results clearly show that the proposed approach has obvious advantages of classification accuracy and detection efficiency. 展开更多
关键词 Event sequence anomaly detection non-public industrial communication protocols SDN
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A Recovery Algorithm for Self-Stabilizing Communication Protocols 被引量:1
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作者 Li Layuan & Li Chunlin (Department of Computer Science & Technology, Wuhan nansportation University, 430063, P. R. China) 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2000年第1期38-46,共9页
This paper presents a recovery algorithm for self-stabilizing communication protocols. It first describes some concepts and a formal description method for the algorithm. Then it proposes the algorithm procedures, pro... This paper presents a recovery algorithm for self-stabilizing communication protocols. It first describes some concepts and a formal description method for the algorithm. Then it proposes the algorithm procedures, proves its correctness and analyses its complexity. Finally, it also verifies the availability and efficiency of the algorithm by illustrating an example protocol with multi-processes. 展开更多
关键词 Computer networks communication protocols Recovery algorithm SELF-STABILIZATION Multimedia communication networks.
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The Algorithms for Achieving Global States and Self-Stabilization for Communication Protocols
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作者 Li Layuan & Li Chunlin(Department of Computer Science & Engineering. Wuhan Transportation University,430063,P . R. China) 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 1999年第4期34-41,共8页
This paper discusses the algorithms for achieving global states and self-stabilizationfor communication protocols. It first describes a primary algorithm including its suitability forachieving global states and limita... This paper discusses the algorithms for achieving global states and self-stabilizationfor communication protocols. It first describes a primary algorithm including its suitability forachieving global states and limitation of self-stabilization for communication protocols, and thenpresents an improved algorithm that can be suitable to achieve global states and can be also usedto self-stabilizing communication protocols. Filially, it gives the proof of correctness and analysis ofcomplexity of the improved algorithm, and verifies its availability and efficiency by illustrating anexample protocol. 展开更多
关键词 communication protocols Algorithm for achieving global states Self-stabilization Computer networks Multimedia communication networks.
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Falcon Optimization Algorithm-Based Energy Efficient Communication Protocol for Cluster-Based Vehicular Networks
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作者 Youseef Alotaibi B.Rajasekar +1 位作者 R.Jayalakshmi Surendran Rajendran 《Computers, Materials & Continua》 SCIE EI 2024年第3期4243-4262,共20页
Rapid development in Information Technology(IT)has allowed several novel application regions like large outdoor vehicular networks for Vehicle-to-Vehicle(V2V)transmission.Vehicular networks give a safe and more effect... Rapid development in Information Technology(IT)has allowed several novel application regions like large outdoor vehicular networks for Vehicle-to-Vehicle(V2V)transmission.Vehicular networks give a safe and more effective driving experience by presenting time-sensitive and location-aware data.The communication occurs directly between V2V and Base Station(BS)units such as the Road Side Unit(RSU),named as a Vehicle to Infrastructure(V2I).However,the frequent topology alterations in VANETs generate several problems with data transmission as the vehicle velocity differs with time.Therefore,the scheme of an effectual routing protocol for reliable and stable communications is significant.Current research demonstrates that clustering is an intelligent method for effectual routing in a mobile environment.Therefore,this article presents a Falcon Optimization Algorithm-based Energy Efficient Communication Protocol for Cluster-based Routing(FOA-EECPCR)technique in VANETS.The FOA-EECPCR technique intends to group the vehicles and determine the shortest route in the VANET.To accomplish this,the FOA-EECPCR technique initially clusters the vehicles using FOA with fitness functions comprising energy,distance,and trust level.For the routing process,the Sparrow Search Algorithm(SSA)is derived with a fitness function that encompasses two variables,namely,energy and distance.A series of experiments have been conducted to exhibit the enhanced performance of the FOA-EECPCR method.The experimental outcomes demonstrate the enhanced performance of the FOA-EECPCR approach over other current methods. 展开更多
关键词 Vehicular networks communication protocol CLUSTERING falcon optimization algorithm ROUTING
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Studies on Algorithms for Self-StabilizingCommunication Protocols
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作者 李腊元 李春林 《Journal of Computer Science & Technology》 SCIE EI CSCD 1999年第6期606-613,共8页
in this paper the algorithms for self-stabilizing communication protocols are studied. First some concepts and a formal method for describing theproposed algorithms are described, then an improved algorithm for achiev... in this paper the algorithms for self-stabilizing communication protocols are studied. First some concepts and a formal method for describing theproposed algorithms are described, then an improved algorithm for achieving globalstates is presented. The study shows that the improved algorithm can be appliedto obtain the global states in the case of a loss of cooperation of the different processes in the protocol, which can be used as a recovery point that will be used bythe following recovery procedure. Thus, the improved algorithm can be used toself-stabilize a communication protocol. Meanwhile, a recovery algorithm for selfstabilizing communication protocols is presented. After a failure is detected, allProcesses can eventually know the error. The recovery algorithm uses the contextualinformation exchanged during the progress of the protocol and recorded on the stablememory. The proof of correctness and analysis of complexity for these algorithmshave been made. The availability and efficiency of the algorithms have been verifiedby illustrating the example protocols. Finally, some conclusions and remarks aregiven. 展开更多
关键词 communication protocol SELF-STABILIZATION global state recoveryalgorithm multimedia communication
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Neural-Network-Based Control for Discrete-Time Nonlinear Systems with Input Saturation Under Stochastic Communication Protocol 被引量:6
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作者 Xueli Wang Derui Ding +1 位作者 Hongli Dong Xian-Ming Zhang 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2021年第4期766-778,共13页
In this paper,an adaptive dynamic programming(ADP)strategy is investigated for discrete-time nonlinear systems with unknown nonlinear dynamics subject to input saturation.To save the communication resources between th... In this paper,an adaptive dynamic programming(ADP)strategy is investigated for discrete-time nonlinear systems with unknown nonlinear dynamics subject to input saturation.To save the communication resources between the controller and the actuators,stochastic communication protocols(SCPs)are adopted to schedule the control signal,and therefore the closed-loop system is essentially a protocol-induced switching system.A neural network(NN)-based identifier with a robust term is exploited for approximating the unknown nonlinear system,and a set of switch-based updating rules with an additional tunable parameter of NN weights are developed with the help of the gradient descent.By virtue of a novel Lyapunov function,a sufficient condition is proposed to achieve the stability of both system identification errors and the update dynamics of NN weights.Then,a value iterative ADP algorithm in an offline way is proposed to solve the optimal control of protocol-induced switching systems with saturation constraints,and the convergence is profoundly discussed in light of mathematical induction.Furthermore,an actor-critic NN scheme is developed to approximate the control law and the proposed performance index function in the framework of ADP,and the stability of the closed-loop system is analyzed in view of the Lyapunov theory.Finally,the numerical simulation results are presented to demonstrate the effectiveness of the proposed control scheme. 展开更多
关键词 Adaptive dynamic programming(ADP) constrained inputs neural network(NN) stochastic communication protocols(SCPs) suboptimal control
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A Computing Resource Adjustment Mechanism for Communication Protocol Processing in Centralized Radio Access Networks 被引量:3
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作者 Guowei Zhai Lin Tian +2 位作者 Yiqing Zhou Qian Sun Jinglin Shi 《China Communications》 SCIE CSCD 2016年第12期79-89,共11页
The centralized radio access cellular network infrastructure based on centralized Super Base Station(CSBS) is a promising solution to reduce the high construction cost and energy consumption of conventional cellular n... The centralized radio access cellular network infrastructure based on centralized Super Base Station(CSBS) is a promising solution to reduce the high construction cost and energy consumption of conventional cellular networks. With CSBS, the computing resource for communication protocol processing could be managed flexibly according the protocol load to improve the resource efficiency. Since the protocol load changes frequently and may exceed the capacity of processors, load balancing is needed. However, existing load balancing mechanisms used in data centers cannot satisfy the real-time requirement of the communication protocol processing. Therefore, a new computing resource adjustment scheme is proposed for communication protocol processing in the CSBS architecture. First of all, the main principles of protocol processing resource adjustment is concluded, followed by the analysis on the processing resource outage probability that the computing resource becomes inadequate for protocol processing as load changes. Following the adjustment principles, the proposed scheme is designed to reduce the processing resource outage probability based onthe optimized connected graph which is constructed by the approximate Kruskal algorithm. Simulation re-sults show that compared with the conventional load balancing mechanisms, the proposed scheme can reduce the occurrence number of inadequate processing resource and the additional resource consumption of adjustment greatly. 展开更多
关键词 computing resource adjustment communication protocol processing cloud RAN super BS processing resource outage probability optimized connected graph
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System Performance of Wireless Sensor Network Using LoRa–Zigbee Hybrid Communication 被引量:2
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作者 Van-Truong Truong Anand Nayyar Showkat Ahmad Lone 《Computers, Materials & Continua》 SCIE EI 2021年第8期1615-1635,共21页
Wireless sensor network(WSN)is considered as the fastest growing technology pattern in recent years because of its applicability in varied domains.Many sensor nodes with different sensing functionalities are deployed ... Wireless sensor network(WSN)is considered as the fastest growing technology pattern in recent years because of its applicability in varied domains.Many sensor nodes with different sensing functionalities are deployed in the monitoring area to collect suitable data and transmit it to the gateway.Ensuring communications in heterogeneous WSNs,is a critical issue that needs to be studied.In this research paper,we study the system performance of a heterogeneous WSN using LoRa–Zigbee hybrid communication.Specifically,two Zigbee sensor clusters and two LoRa sensor clusters are used and combined with two Zigbee-to-LoRa converters to communicate in a network managed by a LoRa gateway.The overall system integrates many different sensors in terms of types,communication protocols,and accuracy,which can be used in many applications in realistic environments such as on land,under water,or in the air.In addition to this,a synchronous management software on ThingSpeak Web server and Blynk app is designed.In the proposed system,the token ring protocol in Zigbee network and polling mechanism in LoRa network is used.The system can operate with a packet loss rate of less than 0.5%when the communication range of the Zigbee network is 630 m,and the communication range of the LoRa network is 3.7 km.On the basis of the digital results collected on the management software,this study proves tremendous improvements in the system performance. 展开更多
关键词 Wireless sensor network ZIGBEE LoRa communication protocol CONVERTER packet loss
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The Security Analysis of Two-Step Quantum Direct Communication Protocol in Collective-Rotation Noise Channel 被引量:2
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作者 李剑 孙风琪 +3 位作者 潘泽世 聂金瑞 陈彦桦 袁开国 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第8期1-5,共5页
To analyze the security of two-step quantum direct communication protocol (QDCP) by using Einstein-Podolsky Rosen pair proposed by Deng et al. [Phys. Rev. A 68 (2003)042317] in collective-rotation noise channel, a... To analyze the security of two-step quantum direct communication protocol (QDCP) by using Einstein-Podolsky Rosen pair proposed by Deng et al. [Phys. Rev. A 68 (2003)042317] in collective-rotation noise channel, an excellent model of noise analysis is proposed. In the security analysis, the method of the entropy theory is introduced, and is compared with QDCP, an error rate point Qo(M : (Q0, 1.0)) is given. In different noise levels, if Eve wants to obtain the same amount of information, the error rate Q is distinguishable. The larger the noise level ~ is, the larger the error rate Q is. When the noise level ~ is lower than 11%, the high error rate is 0.153 without eavesdropping. Lastly, the security of the proposed protocol is discussed. It turns out that the quantum channel will be safe when Q 〈 0.153. Similarly, if error rate Q〉 0.153 = Q0, eavesdropping information I 〉 1, which means that there exist eavesdroppers in the quantum channel, and the quantum channel will not be safe anymore. 展开更多
关键词 The Security Analysis of Two-Step Quantum Direct communication Protocol in Collective-Rotation Noise Channel EPR
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Research on a Secure Communication Protocol Based on National Secret SM2 Algorithm 被引量:1
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作者 Youhai Shao Yong Wang +1 位作者 Yun Yang Xiang Wang 《Journal of Computer and Communications》 2022年第1期42-56,共15页
Most of the public key algorithms used in the exchange of information for power data transmission protocols are RSA. The core of the key part of this kind of algorithm system has not been announced. For the domestic s... Most of the public key algorithms used in the exchange of information for power data transmission protocols are RSA. The core of the key part of this kind of algorithm system has not been announced. For the domestic sensitive information data field, there are threats such as preset backdoors and security vulnerabilities. In response to the above problems, the article introduces a secure communication protocol based on the optimized Secret SM2 algorithm, which uses socket programming to achieve two-way encrypted communication between clients and services, and is able to complete the security protection of data encryption transmission, authentication, data tampering, etc., and proves through experiments that the security protocol is more secure than traditional methods, can effectively identify each other, carry out stable and controllable data encryption transmission, and has good applicability. 展开更多
关键词 Secret Algorithm SM2 communication Protocol Hybrid Encryption Security Protection
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Exploration of IoT Nodes Communication Using LoRaWAN in Forest Environment
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作者 Anshul Sharma Divneet Singh Kapoor +3 位作者 Anand Nayyar Basit Qureshi Kiran Jot Singh Khushal Thakur 《Computers, Materials & Continua》 SCIE EI 2022年第6期6239-6256,共18页
The simultaneous advances in the Internet of Things(IoT),Artificial intelligence(AI)and Robotics is going to revolutionize our world in the near future.In recent years,LoRa(Long Range)wireless powered by LoRaWAN(LoRa ... The simultaneous advances in the Internet of Things(IoT),Artificial intelligence(AI)and Robotics is going to revolutionize our world in the near future.In recent years,LoRa(Long Range)wireless powered by LoRaWAN(LoRa Wide Area Network)protocol has attracted the attention of researchers for numerous applications in the IoT domain.LoRa is a low power,unlicensed Industrial,Scientific,and Medical(ISM)bandequipped wireless technology that utilizes a wide area network protocol,i.e.,LoRaWAN,to incorporate itself into the network infrastructure.In this paper,we have evaluated the LoRaWAN communication protocol for the implementation of the IoT(Internet of Things)nodes’communication in a forest scenario.The outdoor performance of LoRa wireless in LoRaWAN,i.e.,the physical layer,has been evaluated in the forest area of Kashirampur Uttarakhand,India.Hence,the present paper aims towards analyzing the performance level of the LoRaWAN technology by observing the changes in Signal to Noise Ratio(SNR),Packet Reception Ratio(PRR)and Received Signal Strength Indicator(RSSI),with respect to the distance between IoT nodes.The article focuses on estimating network lifetime for a specific set of LoRa configuration parameters,hardware selection and power constraints.From the experimental results,it has been observed that transmissions can propagate to a distance of 300 m in the forest environment,while consuming approx.63%less energy for spreading factor 7 at 2 dBm,without incurring significant packet loss with PRR greater than 80%. 展开更多
关键词 LoRa LoRaWAN IOT communication protocol wireless sensor networks packet reception ratio
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Variance-Constrained Filtering Fusion for Nonlinear Cyber-Physical Systems With the Denial-of-Service Attacks and Stochastic Communication Protocol
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作者 Hang Geng Zidong Wang +2 位作者 Yun Chen Xiaojian Yi Yuhua Cheng 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2022年第6期978-989,共12页
In this paper,a new filtering fusion problem is studied for nonlinear cyber-physical systems under errorvariance constraints and denial-of-service attacks.To prevent data collision and reduce communication cost,the st... In this paper,a new filtering fusion problem is studied for nonlinear cyber-physical systems under errorvariance constraints and denial-of-service attacks.To prevent data collision and reduce communication cost,the stochastic communication protocol is adopted in the sensor-to-filter channels to regulate the transmission order of sensors.Each sensor is allowed to enter the network according to the transmission priority decided by a set of independent and identicallydistributed random variables.From the defenders’view,the occurrence of the denial-of-service attack is governed by the randomly Bernoulli-distributed sequence.At the local filtering stage,a set of variance-constrained local filters are designed where the upper bounds(on the filtering error covariances)are first acquired and later minimized by appropriately designing filter parameters.At the fusion stage,all local estimates and error covariances are combined to develop a variance-constrained fusion estimator under the federated fusion rule.Furthermore,the performance of the fusion estimator is examined by studying the boundedness of the fused error covariance.A simulation example is finally presented to demonstrate the effectiveness of the proposed fusion estimator. 展开更多
关键词 Cyber-physical system(CPS) denial-of-service attack stochastic communication protocol(SCP) variance-constrained filtering fusion
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A Hybrid Formal Description Method Based on FSM,CSP and ADT for Communication Protocol
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作者 Li Layman(Wuhan Transportation Universityl 430063, P. R. China) 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 1998年第3期29-38,共10页
Since communication protocol deals with complex issues related to distribution such as communication, concurrency and synchronization, their development needs to be traced by using sophisticated formal description met... Since communication protocol deals with complex issues related to distribution such as communication, concurrency and synchronization, their development needs to be traced by using sophisticated formal description methods. This paper presents a new hybrid formal method for communication protocol specification. In this method, finite state machine (FSM), communication sequential process (CSP) and abstract data type (ADT) are mixed and the best features of these approaches are offered. In this paper, the main formal description techniques (FDT) for protocol engineering are brieny introduced and a hybrid formal description method based on the FSM, CSP and ADT for communication protocol is described. Finally, this paper presents the formal specification of an example protocol for LAN by using the proposed hybrid formal method. The results of studies show that the hybrid formal description method for communication protocol is an available and effective approach. 展开更多
关键词 communication protocol Formal description techniques Protocol engineering Hybrid formal method
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Study of Communication Protocol and Link Establishing Mode of Mine Managing Mobile Communication System of Minute Areas
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作者 杨维 孙继平 苏又平 《International Journal of Mining Science and Technology》 2000年第2期79-82,共4页
This paper studies the communication protocol and link establishing mode of the mine managing mobile communication system consisted of minute areas. The communication protocol suitable for the system is proposed and d... This paper studies the communication protocol and link establishing mode of the mine managing mobile communication system consisted of minute areas. The communication protocol suitable for the system is proposed and designed. 展开更多
关键词 MINE mobile communication communication protocol LAYER LINK
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IoT data analytic algorithms on edge-cloud infrastructure:A review
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作者 Abel E.Edje M.S.Abd Latiff Weng Howe Chan 《Digital Communications and Networks》 SCIE CSCD 2023年第6期1486-1515,共30页
The adoption of Internet of Things(IoT)sensing devices is growing rapidly due to their ability to provide realtime services.However,it is constrained by limited data storage and processing power.It offloads its massiv... The adoption of Internet of Things(IoT)sensing devices is growing rapidly due to their ability to provide realtime services.However,it is constrained by limited data storage and processing power.It offloads its massive data stream to edge devices and the cloud for adequate storage and processing.This further leads to the challenges of data outliers,data redundancies,and cloud resource load balancing that would affect the execution and outcome of data streams.This paper presents a review of existing analytics algorithms deployed on IoT-enabled edge cloud infrastructure that resolved the challenges of data outliers,data redundancies,and cloud resource load balancing.The review highlights the problems solved,the results,the weaknesses of the existing algorithms,and the physical and virtual cloud storage servers for resource load balancing.In addition,it discusses the adoption of network protocols that govern the interaction between the three-layer architecture of IoT sensing devices enabled edge cloud and its prevailing challenges.A total of 72 algorithms covering the categories of classification,regression,clustering,deep learning,and optimization have been reviewed.The classification approach has been widely adopted to solve the problem of redundant data,while clustering and optimization approaches are more used for outlier detection and cloud resource allocation. 展开更多
关键词 Internet of things Cloud platform Edge Analytic algorithms Processes Network communication protocols
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MULTIPLE ELECTRONIC CONTROL UNITS CALIBRATION SYSTEM BASED ON EXPLICIT CALIBRATION PROTOCOL AND J1939 PROTOCOL 被引量:3
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作者 ZHU Keqing XU Quankui YANG Lin ZHUO Bin 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2008年第1期42-46,共5页
The rising number of electronic control units (ECUs) in vehicles and the decreasing time to market have led to the need for advanced methods of calibration. A multi-ECU calibration system was developed based on the ... The rising number of electronic control units (ECUs) in vehicles and the decreasing time to market have led to the need for advanced methods of calibration. A multi-ECU calibration system was developed based on the explicit calibration protocol (XCP) and J1939 communication protocol to satisfy the need of calibrating multiple ECUs simultaneously. The messages in the controller area network (CAN) are defined in the J1939 protocol. Each CAN node can get its own calibration messages and information from other ECUs, and block other messages by qualifying the CAN messages with priority, source or destination address. The data field of the calibration message is designed with the XCP, with CAN acting as the transport layer. The calibration sessions are setup with the event-triggered XCP driver in the master node and the responding XCP driver in the slave nodes. Mirroring calibration variables from ROM to RAM enables the user to calibrate ECUs online. The application example shows that the multi-ECU calibration system can calibrate multiple ECUs simultaneously, and the main program can also accomplish its calculation and send commands to the actuators in time. By the multi-ECU calibration system, the calibration effort and time can be reduced and the variables in ECU can get a better match with the variables of other ECUs. 展开更多
关键词 Electronic control unit (ECU) Calibration Explicit calibration protocol (XCP) J1939 communication protocol Controlled area network (CAN)
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Deep space multi-file delivery protocol based on LT codes 被引量:1
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作者 Ruyan Wang Hua Liang +1 位作者 Hui Zhao Gaofeng Fang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2016年第3期524-530,共7页
A deep space multi-file delivery protocol(DSMDP) based on LT codes is proposed to reduce the influence of long delay and a high bit error rate(BER) in deep space communication. The protocol increases sending redun... A deep space multi-file delivery protocol(DSMDP) based on LT codes is proposed to reduce the influence of long delay and a high bit error rate(BER) in deep space communication. The protocol increases sending redundancy by LT codes to improve the success rate of file delivery, and adopts different protective strategies for different situations of packet loss. At the same time, the multi-file united delivery strategy is adopted to make full use of the retransmission time to reduce the end-toend transmission delay. Furthermore, the protocol determines the quantity of encoded packets according to the feedback for controlling redundancy. The simulation results show that the proposed protocol can significantly reduce the transmission delay of files, which would be effectively suitable for deep space communication environment of high BER and long delay. 展开更多
关键词 deep space communication multi-file delivery protocol LT codes delay
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Control System Design and Implementation at Flexible, Distributed Offshore Sensor Test Sites in the Yangtze Estuary Area
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作者 HU Qingsong JIANG Chao +5 位作者 DU Lin LI Jun CHEN Leilei XIANG Peng ZHANG Hongcheng RAHMAN Hafiz Abd ur 《Journal of Ocean University of China》 SCIE CAS CSCD 2021年第2期285-295,共11页
Marine in situ testing is a necessary step for stereotyping newly developed marine sensors. The use of test sites in the Yangtze Estuary area, which has high turbidity and abundant nutrients, can effectively reduce th... Marine in situ testing is a necessary step for stereotyping newly developed marine sensors. The use of test sites in the Yangtze Estuary area, which has high turbidity and abundant nutrients, can effectively reduce the needed testing time owing to its harsh conditions. Five test stations were established, and a floating buoy and fixed test equipment were designed. A control system, including a sensor connection, data processor, video remote transmission, and corresponding control algorithm, was developed. The control system enabled the nondestructive monitoring of biological attachments and bidirectional, real-time communication between an upper server on land and the control system at the test sites. The dissolved oxygen(DO), temperature, and pH data of DOS600 and DPS600 sensors were compared with those of AP2000 sensors. Temperature recording using the DOS600 sensor was performed nearly as well as that of the AP2000 sensor. The mean DO values(standard deviations) were 8.414 mg L-1(2.068) and 6.896 mg L-1(1.235) for the DOS600 and AP2000 sensors, respectively, indicating that the DOS600 performance was unsatisfactory. The pH recording of the DPS600 was slightly worse than that of the AP2000 sensor. Experimental results showed that the DO value was more easily affected by the buoy movement of waves compared to the pH and temperature. Moreover, data fluctuations showed that the DO and pH parameters were more vulnerable to biofouling than temperature. Waves and biofouling create a harsh test environment, and the performance difference between the developed sensors and a standard sensor can be obtained in a short time period. 展开更多
关键词 offshore sensor test sites Yangtze Estuary control system communication protocol MICROWAVE sensor detection data analysis
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Integration of Manufacturing Services into Virtual Environments over the Internet
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作者 Huiping Shang Zhengxu Zhao 《International Journal of Automation and computing》 EI 2004年第1期89-106,共18页
Virtual reality (VR) is a rapidly developing technology that has a wide spectrum of industrial and commercial applications. Networked (distributed or shared) virtual environments (VE) are of growing interest to modern... Virtual reality (VR) is a rapidly developing technology that has a wide spectrum of industrial and commercial applications. Networked (distributed or shared) virtual environments (VE) are of growing interest to modern manufacturing industry; a dominating use of networked virtual manufacturing environments (VMEs) is on-line visualisation and collaborative control of 3D information. This has to be supported by real-time data transfer. To meet a broad range of common requirements for Internet-based VE communications, particularly for virtual manufacturing and collaborative design and control, this paper presents a networked virtual environment system that is designed to support networked virtual design and manufacturing. The system is implemented with manufacturing message specification (MMS) standards so as to integrate a range of manufacturing services into networked VEs over the Internet. 展开更多
关键词 Distributed virtual environment networked virtual environment shared virtual environment virtual reality (VR) virtual environment (VE) virtual manufacturing virtual manufacturing device (VMD) manufacturing message specification (MMS) communication protocol
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An Investigation of Formal Techniques of Protocol Based on CFSM
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作者 Li LayuanWuhan Jiaotong University, 430063, P. R. China) 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 1997年第2期66-72,共7页
This paper investigates formal techniques of protocol based on communicating finite state machines (CFSM). Taking the protocols POLLEND (PE) and ACKNACK (AN) as the examples, the paper discusses the formal description... This paper investigates formal techniques of protocol based on communicating finite state machines (CFSM). Taking the protocols POLLEND (PE) and ACKNACK (AN) as the examples, the paper discusses the formal description, validation and conversion of protocol with the CFSM, presents a protocol validation method and a protocol conversion algorithm based on the CFSM and demonstrates the applicability of the method and the algorithm using the example protocols PE and AN. 展开更多
关键词 CFSM communication protocol Formal techniques.
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