The Internet evolves to incorporate very-high-bandwidth optical links and more large-delay satellite links. TCP faces new challenges in this unique environment. Theory and experiments showed that TCP becomes inefficie...The Internet evolves to incorporate very-high-bandwidth optical links and more large-delay satellite links. TCP faces new challenges in this unique environment. Theory and experiments showed that TCP becomes inefficient and is prone to be unstable as the per-flow product of bandwidth and latency increases, regardless of the queuing scheme. Variable-structure congestion Control Protocol (VCP) is proposed to address these problems. However, VCP has problem in terms of convergence time, i.e., it takes a long time for a new VCP flow to achieve fair bandwidth allocation if the existing VCP flows have large con- gestion windows. This paper proposed an Extended Variable-structure congestion Control Protocol (EVCP), which adopted a convergence controller. The basic idea of convergence controller is that if a flow has larger window than its fair window, its congestion window should be decreased more aggressively than usual in Multiplicative Decrease (MD) phase. Simulations showed that EVCP has better performance in terms of convergence time while keeping the advantages of VCP.展开更多
The dynamic characteristics of eplicit control protocol (XCP) were investigated with single bottleneck on the microscopic time-scale. Analysis and simulation results show that the bandwidth utilization of an XCP bottl...The dynamic characteristics of eplicit control protocol (XCP) were investigated with single bottleneck on the microscopic time-scale. Analysis and simulation results show that the bandwidth utilization of an XCP bottleneck link converges to 1 at exponential rate, persistent congestion cannot occur at the bottleneck link, and throughput of an arbitrary subset of XCP flows at the bottleneck link converges to its fair share in exponential rate. The XCP has high bandwidth utilization and good fairness properties.展开更多
Most of the internet users connect through wireless networks. Majorpart of internet traffic is carried by Transmission Control Protocol (TCP). It hassome design constraints while operated across wireless networks. TCP...Most of the internet users connect through wireless networks. Majorpart of internet traffic is carried by Transmission Control Protocol (TCP). It hassome design constraints while operated across wireless networks. TCP is the traditional predominant protocol designed for wired networks. To control congestionin the network, TCP used acknowledgment to delivery of packets by the end host.In wired network, packet loss signals congestion in the network. But rather inwireless networks, loss is mainly because of the wireless characteristics such asfading, signal strength etc. When a packet travels across wired and wireless networks, TCP congestion control theory faces problem during handshake betweenthem. This paper focuses on finding this misinterpretation of the losses using crosslayer approach. This paper focuses on increasing bandwidth usage by improvingTCP throughput in wireless environments using cross layer approach and hencenamed the proposed system as CRLTCP. TCP misinterprets wireless loss as congestion loss and unnecessarily reduces congestion window size. Using the signalstrength and frame error rate, the type of loss is identified and accordingly theresponse of TCP is modified. The results show that there is a significant improvement in the throughput of proposed TCP upon which bandwidth usage isincreased.展开更多
A new medium access control protocol for MANs named DQCA(Distributed QueueCyclic Access)is presented in this paper.When the users of DQCA MAN transfer long files,the network will reach a steady state which is fair aft...A new medium access control protocol for MANs named DQCA(Distributed QueueCyclic Access)is presented in this paper.When the users of DQCA MAN transfer long files,the network will reach a steady state which is fair after a transient period.The transient pe-riod is shorter than that of DQDB.DQCA MAN has the flexibility in bandwidth allocation:the users can achieve different throughputs if the parameters,Pmax(i),are set to be differ-ent.The implementation of priority mechanism is simpler than that of DQDB.展开更多
A novel distributed cognitive radio multichannel medium access protocol without common control channel was proposed.The protocol divided a transmission interval into two parts for exchanging control information and da...A novel distributed cognitive radio multichannel medium access protocol without common control channel was proposed.The protocol divided a transmission interval into two parts for exchanging control information and data,respectively.In addition to evaluating system saturation throughput of the proposed protocol,a three-dimensional multi channel Markov chain model to describe the sate of the cognitive users (CUs) in dynamic spectrum access was presented.The proposed analysis was applied to the packet transmission schemes employed by the basic,RTS/CTS access mechanism adopted in the normal IEEE 802.11.Analyzing the advantage of the two methods,a hybrid access mechanism was proposed to improve the system throughput.The simulation results show that the experiment results are close to the value computed by the model (less than 5%),and the proposed protocol significantly improves the performance of the system throughput by borrowing the licensed spectrum.By analyzing the dependence of throughput on system parameters,hybrid mechanism dynamically selecting access mechanism can maintain high throughput.展开更多
With the development of information technology and cloud computing,data sharing has become an important part of scientific research.In traditional data sharing,data is stored on a third-party storage platform,which ca...With the development of information technology and cloud computing,data sharing has become an important part of scientific research.In traditional data sharing,data is stored on a third-party storage platform,which causes the owner to lose control of the data.As a result,there are issues of intentional data leakage and tampering by third parties,and the private information contained in the data may lead to more significant issues.Furthermore,data is frequently maintained on multiple storage platforms,posing significant hurdles in terms of enlisting multiple parties to engage in data sharing while maintaining consistency.In this work,we propose a new architecture for applying blockchains to data sharing and achieve efficient and reliable data sharing among heterogeneous blockchains.We design a new data sharing transaction mechanism based on the system architecture to protect the security of the raw data and the processing process.We also design and implement a hybrid concurrency control protocol to overcome issues caused by the large differences in blockchain performance in our system and to improve the success rate of data sharing transactions.We took Ethereum and Hyperledger Fabric as examples to conduct crossblockchain data sharing experiments.The results show that our system achieves data sharing across heterogeneous blockchains with reasonable performance and has high scalability.展开更多
Recent advances in optical networking technologies, particularly DWDM and MEMS, promise the transmission and switching of huge bandwidth capacity. The carriers have convinced of that their revenue must be earned from ...Recent advances in optical networking technologies, particularly DWDM and MEMS, promise the transmission and switching of huge bandwidth capacity. The carriers have convinced of that their revenue must be earned from efficient bandwidth management instead of unsophisticated increase in capacity. The distributed control plane can offer more flexibility, reliability and scalability, whose functions include addressing, resource and topology discovery, route computation, provisioning and restoration. Genera...展开更多
This paper investigates the fnite-time consensus problem of multi-agent systems with single and double integrator dynamics,respectively.Some novel nonlinear protocols are constructed for frst-order and second-order le...This paper investigates the fnite-time consensus problem of multi-agent systems with single and double integrator dynamics,respectively.Some novel nonlinear protocols are constructed for frst-order and second-order leader-follower multi-agent systems,respectively.Based on the fnite-time control technique,the graph theory and Lyapunov direct method,some theoretical results are proposed to ensure that the states of all the follower agents can converge to its leader agent s state in fnite time.Finally,some simulation results are presented to illustrate the efectiveness of our theoretical results.展开更多
An analytic control protocol of two types of finite dimensional quantum systems is proposed. The system can be driven to an arbitrary target state using cosine classical fields in finite cycles. The control parameters...An analytic control protocol of two types of finite dimensional quantum systems is proposed. The system can be driven to an arbitrary target state using cosine classical fields in finite cycles. The control parameters which are time periods of interaction between systems and control fields in each cycle are connected with the probability amplitudes of target states via trigonometrical functions and can be determined analytically.展开更多
The industrial Internet of Things(IIoT)is a new indus-trial idea that combines the latest information and communica-tion technologies with the industrial economy.In this paper,a cloud control structure is designed for...The industrial Internet of Things(IIoT)is a new indus-trial idea that combines the latest information and communica-tion technologies with the industrial economy.In this paper,a cloud control structure is designed for IIoT in cloud-edge envi-ronment with three modes of 5G.For 5G based IIoT,the time sensitive network(TSN)service is introduced in transmission network.A 5G logical TSN bridge is designed to transport TSN streams over 5G framework to achieve end-to-end configuration.For a transmission control protocol(TCP)model with nonlinear disturbance,time delay and uncertainties,a robust adaptive fuzzy sliding mode controller(AFSMC)is given with control rule parameters.IIoT workflows are made up of a series of subtasks that are linked by the dependencies between sensor datasets and task flows.IIoT workflow scheduling is a non-deterministic polynomial(NP)-hard problem in cloud-edge environment.An adaptive and non-local-convergent particle swarm optimization(ANCPSO)is designed with nonlinear inertia weight to avoid falling into local optimum,which can reduce the makespan and cost dramatically.Simulation and experiments demonstrate that ANCPSO has better performances than other classical algo-rithms.展开更多
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
BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a major public health problem worldwide. Pulmonary rehabilitation (PR) is an established intervention for the management of patients with COPD. Exercise...BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a major public health problem worldwide. Pulmonary rehabilitation (PR) is an established intervention for the management of patients with COPD. Exercise training is an important part of PR, and its effectiveness in patients with COPD is well established. However, alternative methods of PR training such as Daoyin have not been appropriately studied. Hence, alternative forms of exercise training that require less exercise equipment and no specific training place should be evaluated. This paper describes the study protocol of a clinical trial that aims to determine if pulmonary Daoyin training will improve the exercise capacity and psychosocial function of patients with COPD in China. METHODS AND DESIGN: A multicenter, randomized, controlled trial will be conducted. A total of 464 patients meeting the inclusion criteria will be enrolled into this study with 232 patients in each of the trial group and the control group. Based on patient education, patients in the trial group will receive pulmonary Daoyin and continue with their usual therapy for three months. In the control group, patients will continue with their usual therapy. The primary outcome measures are exercise capacity assessed by the six-minute walking distance test and lung function. Secondary outcomes include dyspnea and quality of life. Measurements will be taken at baseline (month 0) and after the study period (month 3). DISCUSSION: It is hypothesized that pulmonary Daoyin will have beneficial effects in improving exercise capacity and psychosocial function of patients with stable COPD, and will provide an alternative form of exercise training that is accessible for the large number of people with COPD. TRIAL REGISTRATION: This trial has been registered in ClinicalTrials.gov. The identifier is NCT01482000.展开更多
BACKGROUND: Parkinson's disease (PD) is a complicated disease, commonly diagnosed among the elderly, which leads to degeneration of the central nervous system. It presently lacks an effective therapy for its compl...BACKGROUND: Parkinson's disease (PD) is a complicated disease, commonly diagnosed among the elderly, which leads to degeneration of the central nervous system. It presently lacks an effective therapy for its complex pathogenesis. Adverse effects from Western drug-based medical intervention prevent long-term adherence to these therapies in many patients. Traditional Chinese medicine (TCM) has long been used to improve the treatment of PD by alleviating the toxic and adverse effects of Western drug-based intervention. Therefore, the aim of this study is to evaluate the efficacy and safety of Xifeng Dingchan Pill (XFDCP), a compound traditional Chinese herbal medicine, taken in conjunction with Western medicine in the treatment of PD patients at different stages in the progression of the disease. METHODS AND DESIGN: This is a multicenter, randomized controlled trial. In total, 320 patients with early- (n = 160) and middle-stage PD (n = 160) will be enrolled and divided evenly into control and trial groups. Of the 160 patients with early-stage PD, the trial group (n = 80) will be given XFDCP, and the control group (n = 80) will be given Madopar. Of the 160 patients with middle-stage PD, the trial group (n = 80) will be given XFDCP combined with Madopar and Piribedil, and the control group (n = 80) will be given Madopar and Piribedil. The Unified Parkinson's Disease Rating Scale scores, TCM symptoms scores, quality of life, change of Madopar's dosage and the toxic and adverse effects of Madopar will be observed during a 3-month treatment period and through a further 6-month follow-up period. DISCUSSION: It is hypothesized that XFDCP, combined with Madopar and Piribedil, will have beneficial effects on patients with PD. The results of this study will provide evidence for developing a comprehensive therapy regimen, which can delay the progress of the disease and improve the quality of life for PD patients in different stages. TRIAL REGISTRATION: This trial has been registered in the Chinese Clinical Trial Registry with the identifer ChiCTR-TRC-12002150.展开更多
BACKGROUND: Rheumatoid arthritis (RA), as a common systemic inflammatory autoimmune disease, affects approximately 1 in 100 individuals. Effective treatment for RA is not yet available because current research does...BACKGROUND: Rheumatoid arthritis (RA), as a common systemic inflammatory autoimmune disease, affects approximately 1 in 100 individuals. Effective treatment for RA is not yet available because current research does not have a clear understanding of the etiology and pathogenesis of RA. Xinfeng Capsule, a patent Chinese herbal medicine, has been used in the treatment of RA in recent years. Despite its reported clinical efficacy, there are no large-sample, multicenter, randomized trials that support the use of Xinfeng Capsule for RA. Therefore, we designed a randomized, double-blind, multicenter, placebo-controlled trial to assess the efficacy and safety of Xinfeng Capsule in the treatment of RA. METHODS AND DESIGN: This is a 12-week, randomized, placebo-controlled, double-blind, multicenter trial on the treatment of RA. The participants will be randomly assigned to the experimental group and the control group at a ratio of 1:1. Participants in the experimental group will receive Xinfeng Capsule and a pharmaceutical placebo (imitation leflunomide). The control group will receive leflunomide and an herbal placebo (imitation Xinfeng Capsule). The American College of Rheumatology (ACR) Criteria for RA will be used to measure the efficacy of the Xinfeng Capsule. The primary outcome measure will be the percentage of study participants who achieve an ACR 20% response rate (ACR20), which will be measured every 4 weeks after randomization. Secondary outcomes will include the ACR50 and ACR70 responses, the side effects of the medications, the Disease Activity Score 28, RA biomarkers, quality of life, and X-rays of the hands and wrists. The first four of the secondary outcomes will be measured every 4 weeks and the others will be measured at baseline and after 12 weeks of treatment. DISCUSSION: The result of this trial will help to evaluate whether Xinfeng Capsule is effective and safe in the treatment of RA. TRIAL REGISTRATION: This trial has been registered in ClinicalTrials.gov. The identifier is N CT01774877.展开更多
Based on the analysis of the covert channel's working mechanism of the internet control message protocol (ICMP) in internet protocol version 4 (IPv4) and Internet Protocol version 6 (IPv6), the ICMP covert cha...Based on the analysis of the covert channel's working mechanism of the internet control message protocol (ICMP) in internet protocol version 4 (IPv4) and Internet Protocol version 6 (IPv6), the ICMP covert channd's algorithms of the IPv4 and IPv6 are presented, which enable automatic channeling upon IPv4/v6 nodes with non-IPv4-compatible address, and the key transmission is achieved by using this channel in the embedded Internet terminal. The result shows that the covert channel's algorithm, which we implemented if, set correct, the messages of this covert channel might go through the gateway and enter the local area network.展开更多
The Internet Control Message Protocol(ICMP)covert tunnel refers to a network attack that encapsulates malicious data in the data part of the ICMP protocol for transmission.Its concealment is stronger and it is not eas...The Internet Control Message Protocol(ICMP)covert tunnel refers to a network attack that encapsulates malicious data in the data part of the ICMP protocol for transmission.Its concealment is stronger and it is not easy to be discovered.Most detection methods are detecting the existence of channels instead of clarifying specific attack intentions.In this paper,we propose an ICMP covert tunnel attack intent detection framework ICMPTend,which includes five steps:data collection,feature dictionary construction,data preprocessing,model construction,and attack intent prediction.ICMPTend can detect a variety of attack intentions,such as shell attacks,sensitive directory access,communication protocol traffic theft,filling tunnel reserved words,and other common network attacks.We extract features from five types of attack intent found in ICMP channels.We build a multi-dimensional dictionary of malicious features,including shell attacks,sensitive directory access,communication protocol traffic theft,filling tunnel reserved words,and other common network attack keywords.For the high-dimensional and independent characteristics of ICMP traffic,we use a support vector machine(SVM)as a multi-class classifier.The experimental results show that the average accuracy of ICMPTend is 92%,training ICMPTend only takes 55 s,and the prediction time is only 2 s,which can effectively identify the attack intention of ICMP.展开更多
OAM (Operations, Administration and Maintenance) system is a very impo rtant component of 3G cellular network. In order to acquire overall managemen t, fast response and steady operation, an SCTP (Stream Control Trans...OAM (Operations, Administration and Maintenance) system is a very impo rtant component of 3G cellular network. In order to acquire overall managemen t, fast response and steady operation, an SCTP (Stream Control Transmission Prot ocol) based OAM, i.e., SOAM system was proposed. SOAM implements new characters of SCTP such as multi-stream, enforced SACK and heartbeat mechanism on its tran sport layer. These characters help SOAM decrease the message transmission delay and accelerate the link failure detection. Besides, a new component named SOAM agent was introduced to improve the operation efficiency of SOAM. The experim ental results prove the proposed SOAM system achieves better performance on sign aling transmission compared with conventional TCP based OAM system.展开更多
This paper proposes a new multi-channel Medium Access Control (MAC) protocol named as Dual Reservation Code Division Multiple Access (CDMA) based MAC protocol with Power Control (DRCPC). The code channel is divided in...This paper proposes a new multi-channel Medium Access Control (MAC) protocol named as Dual Reservation Code Division Multiple Access (CDMA) based MAC protocol with Power Control (DRCPC). The code channel is divided into common channel,broadcast channel and several data chan-nels. And dynamic power control mechanism is implemented to reduce near-far interference. Compared with IEEE 802.11 Distributed Coordination Function (DCF) protocol,the results show that the pro-posed mechanism improves the average throughput and limits the transmission delay efficiently.展开更多
In networked control systems (NCS),the control performance depends on not only the control algorithm but also the communication protocol stack.The performance degradation introduced by the heterogeneous and dynamic ...In networked control systems (NCS),the control performance depends on not only the control algorithm but also the communication protocol stack.The performance degradation introduced by the heterogeneous and dynamic communication environment has intensified the need for the reconfigurable protocol stack.In this paper,a novel architecture for the reconfigurable protocol stack is proposed,which is a unified specification of the protocol components and service interfaces supporting both static and dynamic reconfiguration for existing industrial communication standards.Within the architecture,a triple-level self-organization structure is designed to manage the dynamic reconfiguration procedure based on information exchanges inside and outside the protocol stack.Especially,the protocol stack can be self-adaptive to various environment and system requirements through the reconfiguration of working mode,routing and scheduling table.Finally,the study on the protocol of dynamic address management is conducted for the system of controller area network (CAN).The results show the efficiency of our self-organizing architecture for the implementation of a reconfigurable protocol stack.展开更多
Aiming at the weaknesses of LON bus, combining the coexistence of fieldbus and DCS (Distribu ted Control Systems) in control networks, the authors introduce a hierarchical hybrid control network design based on LON an...Aiming at the weaknesses of LON bus, combining the coexistence of fieldbus and DCS (Distribu ted Control Systems) in control networks, the authors introduce a hierarchical hybrid control network design based on LON and master slave RS 422/485 protocol. This design adopts LON as the trunk, master slave RS 422/485 control networks are connected to LON as special subnets by dedicated gateways. It is an implementation method for isomerous control network integration. Data management is ranked according to real time requirements for different network data. The core components, such as control network nodes, router and gateway, are detailed in the paper. The design utilizes both communication advantage of LonWorks technology and the more powerful control ability of universal MCUs or PLCs, thus it greatly increases system response speed and performance cost ratio.展开更多
文摘The Internet evolves to incorporate very-high-bandwidth optical links and more large-delay satellite links. TCP faces new challenges in this unique environment. Theory and experiments showed that TCP becomes inefficient and is prone to be unstable as the per-flow product of bandwidth and latency increases, regardless of the queuing scheme. Variable-structure congestion Control Protocol (VCP) is proposed to address these problems. However, VCP has problem in terms of convergence time, i.e., it takes a long time for a new VCP flow to achieve fair bandwidth allocation if the existing VCP flows have large con- gestion windows. This paper proposed an Extended Variable-structure congestion Control Protocol (EVCP), which adopted a convergence controller. The basic idea of convergence controller is that if a flow has larger window than its fair window, its congestion window should be decreased more aggressively than usual in Multiplicative Decrease (MD) phase. Simulations showed that EVCP has better performance in terms of convergence time while keeping the advantages of VCP.
基金The National Natural Science Foundation of China (No. 60503049)
文摘The dynamic characteristics of eplicit control protocol (XCP) were investigated with single bottleneck on the microscopic time-scale. Analysis and simulation results show that the bandwidth utilization of an XCP bottleneck link converges to 1 at exponential rate, persistent congestion cannot occur at the bottleneck link, and throughput of an arbitrary subset of XCP flows at the bottleneck link converges to its fair share in exponential rate. The XCP has high bandwidth utilization and good fairness properties.
文摘Most of the internet users connect through wireless networks. Majorpart of internet traffic is carried by Transmission Control Protocol (TCP). It hassome design constraints while operated across wireless networks. TCP is the traditional predominant protocol designed for wired networks. To control congestionin the network, TCP used acknowledgment to delivery of packets by the end host.In wired network, packet loss signals congestion in the network. But rather inwireless networks, loss is mainly because of the wireless characteristics such asfading, signal strength etc. When a packet travels across wired and wireless networks, TCP congestion control theory faces problem during handshake betweenthem. This paper focuses on finding this misinterpretation of the losses using crosslayer approach. This paper focuses on increasing bandwidth usage by improvingTCP throughput in wireless environments using cross layer approach and hencenamed the proposed system as CRLTCP. TCP misinterprets wireless loss as congestion loss and unnecessarily reduces congestion window size. Using the signalstrength and frame error rate, the type of loss is identified and accordingly theresponse of TCP is modified. The results show that there is a significant improvement in the throughput of proposed TCP upon which bandwidth usage isincreased.
基金Supported by the Institute of Electronic Science of China and the National Natural Science Foundation of China.
文摘A new medium access control protocol for MANs named DQCA(Distributed QueueCyclic Access)is presented in this paper.When the users of DQCA MAN transfer long files,the network will reach a steady state which is fair after a transient period.The transient pe-riod is shorter than that of DQDB.DQCA MAN has the flexibility in bandwidth allocation:the users can achieve different throughputs if the parameters,Pmax(i),are set to be differ-ent.The implementation of priority mechanism is simpler than that of DQDB.
基金Project(61071104) supported by the National Natural Science Foundation of China
文摘A novel distributed cognitive radio multichannel medium access protocol without common control channel was proposed.The protocol divided a transmission interval into two parts for exchanging control information and data,respectively.In addition to evaluating system saturation throughput of the proposed protocol,a three-dimensional multi channel Markov chain model to describe the sate of the cognitive users (CUs) in dynamic spectrum access was presented.The proposed analysis was applied to the packet transmission schemes employed by the basic,RTS/CTS access mechanism adopted in the normal IEEE 802.11.Analyzing the advantage of the two methods,a hybrid access mechanism was proposed to improve the system throughput.The simulation results show that the experiment results are close to the value computed by the model (less than 5%),and the proposed protocol significantly improves the performance of the system throughput by borrowing the licensed spectrum.By analyzing the dependence of throughput on system parameters,hybrid mechanism dynamically selecting access mechanism can maintain high throughput.
基金supported by the National Key Research and Development Program of China(Nos.2020YFB1707900,2021YFB2700700)the National Natural Science Foundation of China(NSFC)(Grant No.62072035)+4 种基金the Open Research Projects of Zhejiang Lab(No.2020KE0AB04)CCF-Huawei Database System Innovation Research Plan(No.CCF-HuaweiDBIR2021007B)Ye Yuan is supported by the NSFC(Grant Nos.61932004,62225203,U21A20516)Xiaochun Yang is supported by the National Key Research and Development Program of China(No.2020YFB1707900)Guoren Wang is supported by the NSFC(Nos.61732003,U2001211).
文摘With the development of information technology and cloud computing,data sharing has become an important part of scientific research.In traditional data sharing,data is stored on a third-party storage platform,which causes the owner to lose control of the data.As a result,there are issues of intentional data leakage and tampering by third parties,and the private information contained in the data may lead to more significant issues.Furthermore,data is frequently maintained on multiple storage platforms,posing significant hurdles in terms of enlisting multiple parties to engage in data sharing while maintaining consistency.In this work,we propose a new architecture for applying blockchains to data sharing and achieve efficient and reliable data sharing among heterogeneous blockchains.We design a new data sharing transaction mechanism based on the system architecture to protect the security of the raw data and the processing process.We also design and implement a hybrid concurrency control protocol to overcome issues caused by the large differences in blockchain performance in our system and to improve the success rate of data sharing transactions.We took Ethereum and Hyperledger Fabric as examples to conduct crossblockchain data sharing experiments.The results show that our system achieves data sharing across heterogeneous blockchains with reasonable performance and has high scalability.
文摘Recent advances in optical networking technologies, particularly DWDM and MEMS, promise the transmission and switching of huge bandwidth capacity. The carriers have convinced of that their revenue must be earned from efficient bandwidth management instead of unsophisticated increase in capacity. The distributed control plane can offer more flexibility, reliability and scalability, whose functions include addressing, resource and topology discovery, route computation, provisioning and restoration. Genera...
基金supported by National Basic Research Program of China (973 Program) (No.2010CB731800)National Natural Science Foundation of China (Nos.60934003 and 61074065)Natural Science Foundation of Hebei Province (No.F2012203119)
文摘This paper investigates the fnite-time consensus problem of multi-agent systems with single and double integrator dynamics,respectively.Some novel nonlinear protocols are constructed for frst-order and second-order leader-follower multi-agent systems,respectively.Based on the fnite-time control technique,the graph theory and Lyapunov direct method,some theoretical results are proposed to ensure that the states of all the follower agents can converge to its leader agent s state in fnite time.Finally,some simulation results are presented to illustrate the efectiveness of our theoretical results.
基金Supported by the National Science Foundation of China under Grant Nos.11075108 and 61374057
文摘An analytic control protocol of two types of finite dimensional quantum systems is proposed. The system can be driven to an arbitrary target state using cosine classical fields in finite cycles. The control parameters which are time periods of interaction between systems and control fields in each cycle are connected with the probability amplitudes of target states via trigonometrical functions and can be determined analytically.
文摘The industrial Internet of Things(IIoT)is a new indus-trial idea that combines the latest information and communica-tion technologies with the industrial economy.In this paper,a cloud control structure is designed for IIoT in cloud-edge envi-ronment with three modes of 5G.For 5G based IIoT,the time sensitive network(TSN)service is introduced in transmission network.A 5G logical TSN bridge is designed to transport TSN streams over 5G framework to achieve end-to-end configuration.For a transmission control protocol(TCP)model with nonlinear disturbance,time delay and uncertainties,a robust adaptive fuzzy sliding mode controller(AFSMC)is given with control rule parameters.IIoT workflows are made up of a series of subtasks that are linked by the dependencies between sensor datasets and task flows.IIoT workflow scheduling is a non-deterministic polynomial(NP)-hard problem in cloud-edge environment.An adaptive and non-local-convergent particle swarm optimization(ANCPSO)is designed with nonlinear inertia weight to avoid falling into local optimum,which can reduce the makespan and cost dramatically.Simulation and experiments demonstrate that ANCPSO has better performances than other classical algo-rithms.
文摘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.
基金supported by 2011 Special Fund for TCM-scientific Research in the Public Interest of Ministry of Finance, People’s Republic of ChinaState Administration of Traditional Chinese Medicine (No. 201107002)
文摘BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a major public health problem worldwide. Pulmonary rehabilitation (PR) is an established intervention for the management of patients with COPD. Exercise training is an important part of PR, and its effectiveness in patients with COPD is well established. However, alternative methods of PR training such as Daoyin have not been appropriately studied. Hence, alternative forms of exercise training that require less exercise equipment and no specific training place should be evaluated. This paper describes the study protocol of a clinical trial that aims to determine if pulmonary Daoyin training will improve the exercise capacity and psychosocial function of patients with COPD in China. METHODS AND DESIGN: A multicenter, randomized, controlled trial will be conducted. A total of 464 patients meeting the inclusion criteria will be enrolled into this study with 232 patients in each of the trial group and the control group. Based on patient education, patients in the trial group will receive pulmonary Daoyin and continue with their usual therapy for three months. In the control group, patients will continue with their usual therapy. The primary outcome measures are exercise capacity assessed by the six-minute walking distance test and lung function. Secondary outcomes include dyspnea and quality of life. Measurements will be taken at baseline (month 0) and after the study period (month 3). DISCUSSION: It is hypothesized that pulmonary Daoyin will have beneficial effects in improving exercise capacity and psychosocial function of patients with stable COPD, and will provide an alternative form of exercise training that is accessible for the large number of people with COPD. TRIAL REGISTRATION: This trial has been registered in ClinicalTrials.gov. The identifier is NCT01482000.
基金Specific Research Funding for the Traditional Chinese Medicine Industry of State Administration of Traditional Chinese Medicine (No.200807052)
文摘BACKGROUND: Parkinson's disease (PD) is a complicated disease, commonly diagnosed among the elderly, which leads to degeneration of the central nervous system. It presently lacks an effective therapy for its complex pathogenesis. Adverse effects from Western drug-based medical intervention prevent long-term adherence to these therapies in many patients. Traditional Chinese medicine (TCM) has long been used to improve the treatment of PD by alleviating the toxic and adverse effects of Western drug-based intervention. Therefore, the aim of this study is to evaluate the efficacy and safety of Xifeng Dingchan Pill (XFDCP), a compound traditional Chinese herbal medicine, taken in conjunction with Western medicine in the treatment of PD patients at different stages in the progression of the disease. METHODS AND DESIGN: This is a multicenter, randomized controlled trial. In total, 320 patients with early- (n = 160) and middle-stage PD (n = 160) will be enrolled and divided evenly into control and trial groups. Of the 160 patients with early-stage PD, the trial group (n = 80) will be given XFDCP, and the control group (n = 80) will be given Madopar. Of the 160 patients with middle-stage PD, the trial group (n = 80) will be given XFDCP combined with Madopar and Piribedil, and the control group (n = 80) will be given Madopar and Piribedil. The Unified Parkinson's Disease Rating Scale scores, TCM symptoms scores, quality of life, change of Madopar's dosage and the toxic and adverse effects of Madopar will be observed during a 3-month treatment period and through a further 6-month follow-up period. DISCUSSION: It is hypothesized that XFDCP, combined with Madopar and Piribedil, will have beneficial effects on patients with PD. The results of this study will provide evidence for developing a comprehensive therapy regimen, which can delay the progress of the disease and improve the quality of life for PD patients in different stages. TRIAL REGISTRATION: This trial has been registered in the Chinese Clinical Trial Registry with the identifer ChiCTR-TRC-12002150.
基金supported by the Twelfth Five-Year Support Project of the Ministry of Science and Technology for clinical studies investigating Xin'an medicine in the treatment of complicated ascites diseases(No.2012BAI26B02)
文摘BACKGROUND: Rheumatoid arthritis (RA), as a common systemic inflammatory autoimmune disease, affects approximately 1 in 100 individuals. Effective treatment for RA is not yet available because current research does not have a clear understanding of the etiology and pathogenesis of RA. Xinfeng Capsule, a patent Chinese herbal medicine, has been used in the treatment of RA in recent years. Despite its reported clinical efficacy, there are no large-sample, multicenter, randomized trials that support the use of Xinfeng Capsule for RA. Therefore, we designed a randomized, double-blind, multicenter, placebo-controlled trial to assess the efficacy and safety of Xinfeng Capsule in the treatment of RA. METHODS AND DESIGN: This is a 12-week, randomized, placebo-controlled, double-blind, multicenter trial on the treatment of RA. The participants will be randomly assigned to the experimental group and the control group at a ratio of 1:1. Participants in the experimental group will receive Xinfeng Capsule and a pharmaceutical placebo (imitation leflunomide). The control group will receive leflunomide and an herbal placebo (imitation Xinfeng Capsule). The American College of Rheumatology (ACR) Criteria for RA will be used to measure the efficacy of the Xinfeng Capsule. The primary outcome measure will be the percentage of study participants who achieve an ACR 20% response rate (ACR20), which will be measured every 4 weeks after randomization. Secondary outcomes will include the ACR50 and ACR70 responses, the side effects of the medications, the Disease Activity Score 28, RA biomarkers, quality of life, and X-rays of the hands and wrists. The first four of the secondary outcomes will be measured every 4 weeks and the others will be measured at baseline and after 12 weeks of treatment. DISCUSSION: The result of this trial will help to evaluate whether Xinfeng Capsule is effective and safe in the treatment of RA. TRIAL REGISTRATION: This trial has been registered in ClinicalTrials.gov. The identifier is N CT01774877.
基金Supported by the National Natural Science Foun-dation of China (90104005 ,66973034)
文摘Based on the analysis of the covert channel's working mechanism of the internet control message protocol (ICMP) in internet protocol version 4 (IPv4) and Internet Protocol version 6 (IPv6), the ICMP covert channd's algorithms of the IPv4 and IPv6 are presented, which enable automatic channeling upon IPv4/v6 nodes with non-IPv4-compatible address, and the key transmission is achieved by using this channel in the embedded Internet terminal. The result shows that the covert channel's algorithm, which we implemented if, set correct, the messages of this covert channel might go through the gateway and enter the local area network.
基金This research was supported by National Natural Science Foundation of China(Grant Nos.61972048,62072051).
文摘The Internet Control Message Protocol(ICMP)covert tunnel refers to a network attack that encapsulates malicious data in the data part of the ICMP protocol for transmission.Its concealment is stronger and it is not easy to be discovered.Most detection methods are detecting the existence of channels instead of clarifying specific attack intentions.In this paper,we propose an ICMP covert tunnel attack intent detection framework ICMPTend,which includes five steps:data collection,feature dictionary construction,data preprocessing,model construction,and attack intent prediction.ICMPTend can detect a variety of attack intentions,such as shell attacks,sensitive directory access,communication protocol traffic theft,filling tunnel reserved words,and other common network attacks.We extract features from five types of attack intent found in ICMP channels.We build a multi-dimensional dictionary of malicious features,including shell attacks,sensitive directory access,communication protocol traffic theft,filling tunnel reserved words,and other common network attack keywords.For the high-dimensional and independent characteristics of ICMP traffic,we use a support vector machine(SVM)as a multi-class classifier.The experimental results show that the average accuracy of ICMPTend is 92%,training ICMPTend only takes 55 s,and the prediction time is only 2 s,which can effectively identify the attack intention of ICMP.
基金High-Tech Research and DevelopmentProgram of China (No. 2003AA123310)
文摘OAM (Operations, Administration and Maintenance) system is a very impo rtant component of 3G cellular network. In order to acquire overall managemen t, fast response and steady operation, an SCTP (Stream Control Transmission Prot ocol) based OAM, i.e., SOAM system was proposed. SOAM implements new characters of SCTP such as multi-stream, enforced SACK and heartbeat mechanism on its tran sport layer. These characters help SOAM decrease the message transmission delay and accelerate the link failure detection. Besides, a new component named SOAM agent was introduced to improve the operation efficiency of SOAM. The experim ental results prove the proposed SOAM system achieves better performance on sign aling transmission compared with conventional TCP based OAM system.
基金Supported by the Science Foundation of Shanghai Mu-nicipal Commission of Science and Technology under contract 045115012.
文摘This paper proposes a new multi-channel Medium Access Control (MAC) protocol named as Dual Reservation Code Division Multiple Access (CDMA) based MAC protocol with Power Control (DRCPC). The code channel is divided into common channel,broadcast channel and several data chan-nels. And dynamic power control mechanism is implemented to reduce near-far interference. Compared with IEEE 802.11 Distributed Coordination Function (DCF) protocol,the results show that the pro-posed mechanism improves the average throughput and limits the transmission delay efficiently.
基金supported by National Natural Science Foundation of China (No. 60674081,No. 60834002,No. 61074145)
文摘In networked control systems (NCS),the control performance depends on not only the control algorithm but also the communication protocol stack.The performance degradation introduced by the heterogeneous and dynamic communication environment has intensified the need for the reconfigurable protocol stack.In this paper,a novel architecture for the reconfigurable protocol stack is proposed,which is a unified specification of the protocol components and service interfaces supporting both static and dynamic reconfiguration for existing industrial communication standards.Within the architecture,a triple-level self-organization structure is designed to manage the dynamic reconfiguration procedure based on information exchanges inside and outside the protocol stack.Especially,the protocol stack can be self-adaptive to various environment and system requirements through the reconfiguration of working mode,routing and scheduling table.Finally,the study on the protocol of dynamic address management is conducted for the system of controller area network (CAN).The results show the efficiency of our self-organizing architecture for the implementation of a reconfigurable protocol stack.
文摘Aiming at the weaknesses of LON bus, combining the coexistence of fieldbus and DCS (Distribu ted Control Systems) in control networks, the authors introduce a hierarchical hybrid control network design based on LON and master slave RS 422/485 protocol. This design adopts LON as the trunk, master slave RS 422/485 control networks are connected to LON as special subnets by dedicated gateways. It is an implementation method for isomerous control network integration. Data management is ranked according to real time requirements for different network data. The core components, such as control network nodes, router and gateway, are detailed in the paper. The design utilizes both communication advantage of LonWorks technology and the more powerful control ability of universal MCUs or PLCs, thus it greatly increases system response speed and performance cost ratio.