The state estimation plays an irreplaceable role in many real applications since it lays the foundation for decision-making and control. This paper studies the multi-sensor estimation problem for a contention-based un...The state estimation plays an irreplaceable role in many real applications since it lays the foundation for decision-making and control. This paper studies the multi-sensor estimation problem for a contention-based unreliable wireless network. At each time step, no more than one sensor can communicate with the base station due to the potential contention and collision. In addition, data packets may be lost during transmission since wireless channels are unreliable. A novel packet arrival model is proposed which simultaneously takes into account the above two issues. Two scenarios of wireless sensor networks （WSNs） are considered： the sensors transmit the raw measurements directly and the sensors send the local estimation instead. Based on the obtained packet arrival model, necessary and sufficient stability conditions of the estimation at the base station side are provided for both network scenarios. In particular, all offered stability conditions are expressed by simple inequalities in terms of the packet arrival rates and the spectral radius of the system matrix. Their relationships with existing related results are also discussed. Finally, the proposed results are demonstrated by simulation examples and an environment monitoring prototype system.展开更多
This paper presents a novel real-time routing protocol, called CBRR, with less energy consumption for wireless sensor networks (WSNs). End-to-End real-time requirements are fulfilled with speed or delay constraint at ...This paper presents a novel real-time routing protocol, called CBRR, with less energy consumption for wireless sensor networks (WSNs). End-to-End real-time requirements are fulfilled with speed or delay constraint at each hop through integrating the contention and neighbor table mechanisms. More precisely, CBRR maintains a neighbor table via the contention mechanism being dependent on wireless broadcast instead of beacons. Comprehensive simulations show that CBRR can not only achieve higher performance in static networks, but also work well for dynamic networks.展开更多
Focusing on the ultralow expansion functionality of the crystalized glass containing the cordierite crystal phase with the molar composition 20.7MgO·20.7Al_(2)O_(3)·51.6SiO_(2)·7.0TiO_(2),we systematica...Focusing on the ultralow expansion functionality of the crystalized glass containing the cordierite crystal phase with the molar composition 20.7MgO·20.7Al_(2)O_(3)·51.6SiO_(2)·7.0TiO_(2),we systematically investigated impacts of thermal treatment protocols on T dependence of coefficients of thermal expansion(CTE).Except for the phase compositions,morphology is identified as another important factor to control the T dependence of CTE.By using X-ray diffraction and scanning electron microscope,various modes of T dependence of CTE for crystallized glasses are ascribed to their different phase compositions and microstructure with finely dispersed nanoparticles.These understanding contributes to the further modification of CTE of the crystalized glass by altering their thermal treatment scenarios.展开更多
BACKGROUND Diabetes mellitus has become one of the major pandemics of the 21st century.In this scenario,nursing interventions are essential for improving self-care and quality of life in patients with type 2 diabetes ...BACKGROUND Diabetes mellitus has become one of the major pandemics of the 21st century.In this scenario,nursing interventions are essential for improving self-care and quality of life in patients with type 2 diabetes mellitus.Nursing interventions are crucial for managing the disease and preventing complications.AIM To analyse nursing interventions in recent years through a systematic review and meta-analysis and to propose improvements in care plans.METHODS This study conducted a systematic review and meta-analysis of the impact of nursing interventions on quantitative glycaemic variables,such as glycated haemoglobin and fasting plasma glucose.RESULTS After confirming that the combined effect of all studies from the past 5 years positively impacts quantitative variables,a descriptive analysis of the studies with the most significant changes was conducted.Based on this,an improvement in diabetic patient care protocols has been proposed through follow-up plans tailored to the patient’s technological skills.CONCLUSION The combined results obtained and the proposal for improvement developed in this manuscript could help to improve the quality of life of many people around the world.展开更多
BACKGROUND The discovery of induced pluripotent stem cells revolutionized regenerative medicine,providing a source for generating induced pluripotent stem cell-derived mesenchymal stem cells(iMSCs).AIM To evaluate and...BACKGROUND The discovery of induced pluripotent stem cells revolutionized regenerative medicine,providing a source for generating induced pluripotent stem cell-derived mesenchymal stem cells(iMSCs).AIM To evaluate and compare five iMSC differentiation protocols,assessing their efficiency,phenotypic characteristics,and functional properties relative to primary mesenchymal stem cells(MSCs).METHODS Five iMSC differentiation protocols were assessed:SB431542-based differentiation(iMSC1,iMSC3),an iMatrix-free method(iMSC2),growth factor supplementation(iMSC4),and embryoid body formation with retinoic acid(EB-iMSC).iMSC identity was confirmed according to the International Society for Cell&Gene Therapy 2006 criteria,requiring expression of surface markers(CD105,CD73,CD90)and absence of pluripotency markers.Functional assays were conducted to evaluate differentiation potential(osteogenic and adipogenic),proliferation,mitochondrial function,reactive oxygen species,senescence,and migration.RESULTS All iMSC types expressed MSC markers and lacked pluripotency markers.EBiMSC and iMSC2 showed enhanced osteogenesis(runt-related transcription factor 2;P≤0.01 and P≤0.0001,respectively),while adipogenic potential was reduced in iMSC2(Adipsin;P≤0.01)and EB-iMSC(Adipsin and peroxisome proliferatoractivated receptor gamma;P≤0.0001 and P≤0.01,respectively).Proliferation was comparable or superior to bone marrow MSCs,except in iMSC1,with iMSC4 showing the highest rate(MTT assay;P values ranged from 0.01 to 0.001).Despite reduced mitochondrial health in iMSC3 and iMSC4(P≤0.001),reactive oxygen species levels were lower in all iMSCs(P values ranged from 0.001 to 0.0001),and senescence was significantly reduced in all iMSCs with the exception of iMSC1(P values ranged from 0.01 to 0.0001).Migration was most reduced in iMSC4(P≤0.001 at 24 hours and P≤0.0001 at 48 hours).CONCLUSION While all protocols generated functional iMSCs,variations in differentiation,proliferation,and function emphasize the impact of protocol selection.These findings contribute to optimizing iMSC generation for research and clinical applications.展开更多
Rwanda secured access to one of the world’s most lucrative agricultural markets this month when it finalised a trade protocol allowing fresh avocado exports to China,a deal that could fundamentally alter the trajecto...Rwanda secured access to one of the world’s most lucrative agricultural markets this month when it finalised a trade protocol allowing fresh avocado exports to China,a deal that could fundamentally alter the trajectory of the country’s trade.展开更多
Advance development of wireless technologies and micro-sensor systems have enabled Wireless Sensor Network (WSN) to emerge as a leading solution in many crucial sensor-based applications. WSN deploys numerous resource...Advance development of wireless technologies and micro-sensor systems have enabled Wireless Sensor Network (WSN) to emerge as a leading solution in many crucial sensor-based applications. WSN deploys numerous resource-constrained sensor nodes which have limited power supply, memory and computation capability in a harsh environment. Inefficient routing strategy results in degraded network performance in terms of reliability, latency and energy efficiency. In this paper, a cross-layer design, Contention-based MAC and Routing protocol is proposed, termed Contention/SNIR-Based Forwarding (CSBF) protocol. CSBF utilizes the geographical information of sensor nodes to effectively guide the routing direction towards destination node, thereby enhancing reliability. Furthermore, Signal-to-Noise-plus-Interference Ratio (SNIR) metric is used as a routing parameter to guarantee high quality link for data transmission. A Contention-Winner Relay scheme is utilized to reduce the delays caused by the contention procedure. Energy efficiency is also improved by introducing sleep mode technique in CSBF. The simulation work is carried out via OMNeT++ network simulator. The performance of CSBF is compared with other existing routing protocols such as AODV and DSDV in terms of packet delivery ratio (PDR), average end-to-end (ETE) delay and energy consumption per packet. Simulation results highlight that CSBF outperforms AODV and DSDV protocols in respect of PDR and energy efficiency. CSBF also has the most consistent overall network performance.展开更多
The differences among the extended Canetti ＆ Krawezyk 2007 model （ECK2007） and other four models, i.e., the Bellare ＆ Rogaway （1993, 1995）models （BR93,BR95）, the Bellare, Pointcheval ＆ Rogaway （2000） model ...The differences among the extended Canetti ＆ Krawezyk 2007 model （ECK2007） and other four models, i.e., the Bellare ＆ Rogaway （1993, 1995）models （BR93,BR95）, the Bellare, Pointcheval ＆ Rogaway （2000） model （BPR2000） and the Canetti ＆ Krawczyk （2001） model （CK2001） are given. The relative strength of security among these models is analyzed. To support the implication or non-implication relation among these models, the formal proof or the counter-example is provided.展开更多
There is a lack of appropriate guidelines for realistic user traces, mobility models, routing protocols, considerations of real-life challenges, etc. for general-purpose mobile ad hoc networks （MANET）. In this paper...There is a lack of appropriate guidelines for realistic user traces, mobility models, routing protocols, considerations of real-life challenges, etc. for general-purpose mobile ad hoc networks （MANET）. In this paper, four laptops are used in an open field environment in four scenarios to evaluate the performances of Internet control message protocol （ICMP） based ping and transmission control protocol （TCP） based streaming video applications using optimised link state routing （OLSR） implementation in an IEEE 802.11g wireless network. Corresponding simulations are developed in Network Simulator ns-2 by setting simulation parameters according to the real experiments. Difficulties faced to regenerate real-life scenarios have been discussed and the gaps between reality and simulation are identified. A setup guideline to produce realistic simulation results has been established.展开更多
Most knowledgeable people agree that networking and routing technologies have been around about 25 years. Routing is simultaneously the most complicated function of a network and the most important. It is of the same ...Most knowledgeable people agree that networking and routing technologies have been around about 25 years. Routing is simultaneously the most complicated function of a network and the most important. It is of the same kind that more than 70% of computer application fields are MIS applications. So the challenge in building and using a MIS in the network is developing the means to find, access, and communicate large databases or multi databases systems. Because general databases are not time continuous, in fact, they can not be streaming, so we can't obtain reliable and secure quality of service by deleting some unimportant datagrams in the databases transmission. In this article, we will discuss which kind of routing protocol is the best type for large databases or multi databases systems transmission in the networks.展开更多
The performance of ALOHA, Non-Persistent CSMA protocols and their slotted versions in Packet Radio Network is analyzed in consideration of the time of propagation delay, the time of radio transformation from receiving...The performance of ALOHA, Non-Persistent CSMA protocols and their slotted versions in Packet Radio Network is analyzed in consideration of the time of propagation delay, the time of radio transformation from receiving state to transmitting state, and the time for the radio to sense the carrier. The analysis shows that these parameters are the main factors deteriorating the performance of the protocols, especially for CSMA. The multichannel mode efficiently decreases the effects of these factors and the system capacity is changeable conveniently. Comparing curves and some simulation results are given.展开更多
Recently, location-based routings in wireless sensor networks (WSNs) are attracting a lot of interest in the research community, especially because of its scalability. In location-based routing, the network size is sc...Recently, location-based routings in wireless sensor networks (WSNs) are attracting a lot of interest in the research community, especially because of its scalability. In location-based routing, the network size is scalable without increasing the signalling overhead as routing decisions are inherently localized. Here, each node is aware of its position in the network through some positioning device like GPS and uses this information in the routing mechanism. In this paper, we first discuss the basics of WSNs including the architecture of the network, energy consumption for the components of a typical sensor node, and draw a detailed picture of classification of location-based routing protocols. Then, we present a systematic and comprehensive taxonomy of location-based routing protocols, mostly for sensor networks. All the schemes are subsequently discussed in depth. Finally, we conclude the paper with some insights on potential research directions for location-based routing in WSNs.展开更多
Nonlinear consensus protocols for dynamic directed networks of multi-agent systems with fixed and switching topologies are investigated separately in this paper. Based on the centre manifold reduction technique, nonli...Nonlinear consensus protocols for dynamic directed networks of multi-agent systems with fixed and switching topologies are investigated separately in this paper. Based on the centre manifold reduction technique, nonlinear consensus protocols are presented. We prove that a group of agents can reach a β-consensus, the value of which is the group decision value varying from the minimum and the maximum values of the initial states of the agents. Moreover, we derive the conditions to guarantee that all the agents reach a β-consensus on a desired group decision value. Finally, a simulation study concerning the vertical alignment manoeuvere of a team of unmanned air vehicles is performed. Simulation results show that the nonlinear consensus protocols proposed are more effective than the linear protocols for the formation control of the agents and they are an improvement over existing protocols.展开更多
The Internet of Things(IoT)has been growing over the past few years due to its flexibility and ease of use in real-time applications.The IoT's foremost task is ensuring that there is proper communication among dif...The Internet of Things(IoT)has been growing over the past few years due to its flexibility and ease of use in real-time applications.The IoT's foremost task is ensuring that there is proper communication among different types of applications and devices,and that the application layer protocols fulfill this necessity.However,as the number of applications grows,it is necessary to modify or enhance the application layer protocols according to specific IoT applications,allowing specific issues to be addressed,such as dynamic adaption to network conditions and interoperability.Recently,several IoT application layer protocols have been enhanced and modified according to application requirements.However,no existing survey articles focus on these protocols.In this article,we survey traditional and recent advances in IoT application layer protocols,as well as relevant real-time applications and their adapted application layer protocols for improving performance.As changing the nature of protocols for each application is unrealistic,machine learning offers means of making protocols intelligent and is able to adapt dynamically.In this context,we focus on providing open challenges to drive IoT application layer protocols in such a direction.展开更多
Radio frequency identification(RFID) is a new type of non-contact automatic identification technology.Due to its low energy consumption,low cost,and its adaptability to harsh environments,it has been applied to many f...Radio frequency identification(RFID) is a new type of non-contact automatic identification technology.Due to its low energy consumption,low cost,and its adaptability to harsh environments,it has been applied to many fields.In the RFID systems,data collision is inevitable when the reader sends a communication request and multiple tags respond with simultaneous data transmission.Data collision is prone to causing problems such as:identification delay,spectrum resource waste,a decreased system throughput rate,etc.Therefore,an efficient,stable anti-collision protocol is crucial for RFID systems.This research analysed the current research into RFID anticollision protocols and summarised means for its improvement through the mechanism of implementation of different types anticollision protocols.Finally,a new direction is proposed for the future development of RFID anti-collision protocol systems.展开更多
Relay attack is one of the most threatening challenges against radio frequency identification（RFID） now. Distance bounding protocols have been introduced to thwart relay attacks. They form a family of challenge-resp...Relay attack is one of the most threatening challenges against radio frequency identification（RFID） now. Distance bounding protocols have been introduced to thwart relay attacks. They form a family of challenge-response authentication protocols and confirm the round-trip time at the Rapid Bit Exchange phase. They enable a reader to authenticate and to establish an upper bound on the physical distance to an entrusted tag. We design an effective attack against a family of such protocols to launch the spoofing attacks within effective distance successfully, which demonstrates that existing protocols cannot eliminate such attacks completely. The thesis proposes a new program with time- stamping verification to correct the defect and verify the effectiveness.展开更多
This paper uses a correlation dimension based nonlinear analysis approach to analyse the dynamics of network traffics with three different application protocols-HTTP, FTP and SMTP. First, the phase space is reconstruc...This paper uses a correlation dimension based nonlinear analysis approach to analyse the dynamics of network traffics with three different application protocols-HTTP, FTP and SMTP. First, the phase space is reconstructed and the embedding parameters are obtained by the mutual information method. Secondly, the correlation dimensions of three different traffics are calculated and the results of analysis have demonstrated that the dynamics of the three different application protocol traffics is different from each other in nature, i.e. HTTP and FTP traffics are chaotic, furthermore, the former is more complex than the later; on the other hand, SMTP traffic is stochastic. It is shown that correlation dimension approach is an efficient method to understand and to characterize the nonlinear dynamics of HTTP, FTP and SMTP protocol network traffics. This analysis provided insight into and a more accurate understanding of nonlinear dynamics of internet traffics which have a complex mixture of chaotic and stochastic components.展开更多
From the viewpoint of protocol sequence, analyses are made of the sequence patterns of possible identity authentication protocol under two cases： with or without the trusted third party （TFP）. Ten feasible sequence...From the viewpoint of protocol sequence, analyses are made of the sequence patterns of possible identity authentication protocol under two cases： with or without the trusted third party （TFP）. Ten feasible sequence patterns of authentication protocol with TIP and 5 sequence patterns without TFP are gained. These gained sequence patterns meet the requirements for identity authentication, and basically cover almost all the authentication protocols with TFP and without TFP at present. All of the sequence patterns gained are classified into unilateral or bilateral authentication. Then, according to the sequence symmetry, several good sequence patterns with TFP are evaluated. The accompolished results can provide a reference to design of new identity authentication protocols.展开更多
Medium access control( MAC) protocol of underwater acoustic communication network is a key technology for underwater acoustic networks( UANs). Most of the MAC protocols for wireless terrestrial communication networks ...Medium access control( MAC) protocol of underwater acoustic communication network is a key technology for underwater acoustic networks( UANs). Most of the MAC protocols for wireless terrestrial communication networks have been designed with negligible propagation delay. If it is deployed directly in an underwater environment,the UANs will perform inefficiently. In this paper,the characteristics of underwater acoustic channel are modeled and simulated by using the OPNET simulation tool,which are the speed of sound, propagation loss, and four sources for ambient noise: the turbulence,shipping,wind driven waves and thermal noise. The performance of pure Aloha( P-Aloha),carrier sense multiple access with collision avoidance( CSMA / CA) and multiple access collision avoidance for wireless local area network( MACAW) protocols in underwater acoustic channel environment are evaluated. The different performance of protocols in underwater environment is compared in the simulation.展开更多
Provable security has become a popular approach for analyzing the security of cryptographic protocols.However,writing and verifying proofs by hand are prone to errors.This paper advocates the automatic security proof ...Provable security has become a popular approach for analyzing the security of cryptographic protocols.However,writing and verifying proofs by hand are prone to errors.This paper advocates the automatic security proof framework with sequences of games.We make slight modifications to Blanchet's calculus to make it easy for parsing the initial game.The main contribution of this work is that it introduces algebraic properties with observational equivalences to automatic security proofs,and thus can deal with some practical cryptographic schemes with hard problems.We illustrate the use of algebraic properties in the framework by proving the semantic security of the ElGamal encryption scheme.展开更多
文摘The state estimation plays an irreplaceable role in many real applications since it lays the foundation for decision-making and control. This paper studies the multi-sensor estimation problem for a contention-based unreliable wireless network. At each time step, no more than one sensor can communicate with the base station due to the potential contention and collision. In addition, data packets may be lost during transmission since wireless channels are unreliable. A novel packet arrival model is proposed which simultaneously takes into account the above two issues. Two scenarios of wireless sensor networks （WSNs） are considered： the sensors transmit the raw measurements directly and the sensors send the local estimation instead. Based on the obtained packet arrival model, necessary and sufficient stability conditions of the estimation at the base station side are provided for both network scenarios. In particular, all offered stability conditions are expressed by simple inequalities in terms of the packet arrival rates and the spectral radius of the system matrix. Their relationships with existing related results are also discussed. Finally, the proposed results are demonstrated by simulation examples and an environment monitoring prototype system.
文摘This paper presents a novel real-time routing protocol, called CBRR, with less energy consumption for wireless sensor networks (WSNs). End-to-End real-time requirements are fulfilled with speed or delay constraint at each hop through integrating the contention and neighbor table mechanisms. More precisely, CBRR maintains a neighbor table via the contention mechanism being dependent on wireless broadcast instead of beacons. Comprehensive simulations show that CBRR can not only achieve higher performance in static networks, but also work well for dynamic networks.
基金Funded by National Natural Science Foundation of China(No.52172007)Jiangsu Science and Technology Innovation Project for Carbon Peaking and Carbon Neutrality(No.BE2022035)。
文摘Focusing on the ultralow expansion functionality of the crystalized glass containing the cordierite crystal phase with the molar composition 20.7MgO·20.7Al_(2)O_(3)·51.6SiO_(2)·7.0TiO_(2),we systematically investigated impacts of thermal treatment protocols on T dependence of coefficients of thermal expansion(CTE).Except for the phase compositions,morphology is identified as another important factor to control the T dependence of CTE.By using X-ray diffraction and scanning electron microscope,various modes of T dependence of CTE for crystallized glasses are ascribed to their different phase compositions and microstructure with finely dispersed nanoparticles.These understanding contributes to the further modification of CTE of the crystalized glass by altering their thermal treatment scenarios.
文摘BACKGROUND Diabetes mellitus has become one of the major pandemics of the 21st century.In this scenario,nursing interventions are essential for improving self-care and quality of life in patients with type 2 diabetes mellitus.Nursing interventions are crucial for managing the disease and preventing complications.AIM To analyse nursing interventions in recent years through a systematic review and meta-analysis and to propose improvements in care plans.METHODS This study conducted a systematic review and meta-analysis of the impact of nursing interventions on quantitative glycaemic variables,such as glycated haemoglobin and fasting plasma glucose.RESULTS After confirming that the combined effect of all studies from the past 5 years positively impacts quantitative variables,a descriptive analysis of the studies with the most significant changes was conducted.Based on this,an improvement in diabetic patient care protocols has been proposed through follow-up plans tailored to the patient’s technological skills.CONCLUSION The combined results obtained and the proposal for improvement developed in this manuscript could help to improve the quality of life of many people around the world.
文摘BACKGROUND The discovery of induced pluripotent stem cells revolutionized regenerative medicine,providing a source for generating induced pluripotent stem cell-derived mesenchymal stem cells(iMSCs).AIM To evaluate and compare five iMSC differentiation protocols,assessing their efficiency,phenotypic characteristics,and functional properties relative to primary mesenchymal stem cells(MSCs).METHODS Five iMSC differentiation protocols were assessed:SB431542-based differentiation(iMSC1,iMSC3),an iMatrix-free method(iMSC2),growth factor supplementation(iMSC4),and embryoid body formation with retinoic acid(EB-iMSC).iMSC identity was confirmed according to the International Society for Cell&Gene Therapy 2006 criteria,requiring expression of surface markers(CD105,CD73,CD90)and absence of pluripotency markers.Functional assays were conducted to evaluate differentiation potential(osteogenic and adipogenic),proliferation,mitochondrial function,reactive oxygen species,senescence,and migration.RESULTS All iMSC types expressed MSC markers and lacked pluripotency markers.EBiMSC and iMSC2 showed enhanced osteogenesis(runt-related transcription factor 2;P≤0.01 and P≤0.0001,respectively),while adipogenic potential was reduced in iMSC2(Adipsin;P≤0.01)and EB-iMSC(Adipsin and peroxisome proliferatoractivated receptor gamma;P≤0.0001 and P≤0.01,respectively).Proliferation was comparable or superior to bone marrow MSCs,except in iMSC1,with iMSC4 showing the highest rate(MTT assay;P values ranged from 0.01 to 0.001).Despite reduced mitochondrial health in iMSC3 and iMSC4(P≤0.001),reactive oxygen species levels were lower in all iMSCs(P values ranged from 0.001 to 0.0001),and senescence was significantly reduced in all iMSCs with the exception of iMSC1(P values ranged from 0.01 to 0.0001).Migration was most reduced in iMSC4(P≤0.001 at 24 hours and P≤0.0001 at 48 hours).CONCLUSION While all protocols generated functional iMSCs,variations in differentiation,proliferation,and function emphasize the impact of protocol selection.These findings contribute to optimizing iMSC generation for research and clinical applications.
文摘Rwanda secured access to one of the world’s most lucrative agricultural markets this month when it finalised a trade protocol allowing fresh avocado exports to China,a deal that could fundamentally alter the trajectory of the country’s trade.
文摘Advance development of wireless technologies and micro-sensor systems have enabled Wireless Sensor Network (WSN) to emerge as a leading solution in many crucial sensor-based applications. WSN deploys numerous resource-constrained sensor nodes which have limited power supply, memory and computation capability in a harsh environment. Inefficient routing strategy results in degraded network performance in terms of reliability, latency and energy efficiency. In this paper, a cross-layer design, Contention-based MAC and Routing protocol is proposed, termed Contention/SNIR-Based Forwarding (CSBF) protocol. CSBF utilizes the geographical information of sensor nodes to effectively guide the routing direction towards destination node, thereby enhancing reliability. Furthermore, Signal-to-Noise-plus-Interference Ratio (SNIR) metric is used as a routing parameter to guarantee high quality link for data transmission. A Contention-Winner Relay scheme is utilized to reduce the delays caused by the contention procedure. Energy efficiency is also improved by introducing sleep mode technique in CSBF. The simulation work is carried out via OMNeT++ network simulator. The performance of CSBF is compared with other existing routing protocols such as AODV and DSDV in terms of packet delivery ratio (PDR), average end-to-end (ETE) delay and energy consumption per packet. Simulation results highlight that CSBF outperforms AODV and DSDV protocols in respect of PDR and energy efficiency. CSBF also has the most consistent overall network performance.
文摘The differences among the extended Canetti ＆ Krawezyk 2007 model （ECK2007） and other four models, i.e., the Bellare ＆ Rogaway （1993, 1995）models （BR93,BR95）, the Bellare, Pointcheval ＆ Rogaway （2000） model （BPR2000） and the Canetti ＆ Krawczyk （2001） model （CK2001） are given. The relative strength of security among these models is analyzed. To support the implication or non-implication relation among these models, the formal proof or the counter-example is provided.
文摘There is a lack of appropriate guidelines for realistic user traces, mobility models, routing protocols, considerations of real-life challenges, etc. for general-purpose mobile ad hoc networks （MANET）. In this paper, four laptops are used in an open field environment in four scenarios to evaluate the performances of Internet control message protocol （ICMP） based ping and transmission control protocol （TCP） based streaming video applications using optimised link state routing （OLSR） implementation in an IEEE 802.11g wireless network. Corresponding simulations are developed in Network Simulator ns-2 by setting simulation parameters according to the real experiments. Difficulties faced to regenerate real-life scenarios have been discussed and the gaps between reality and simulation are identified. A setup guideline to produce realistic simulation results has been established.
基金Supported by National Natural Science Foundation of China(6 98730 2 7)
文摘Most knowledgeable people agree that networking and routing technologies have been around about 25 years. Routing is simultaneously the most complicated function of a network and the most important. It is of the same kind that more than 70% of computer application fields are MIS applications. So the challenge in building and using a MIS in the network is developing the means to find, access, and communicate large databases or multi databases systems. Because general databases are not time continuous, in fact, they can not be streaming, so we can't obtain reliable and secure quality of service by deleting some unimportant datagrams in the databases transmission. In this article, we will discuss which kind of routing protocol is the best type for large databases or multi databases systems transmission in the networks.
文摘The performance of ALOHA, Non-Persistent CSMA protocols and their slotted versions in Packet Radio Network is analyzed in consideration of the time of propagation delay, the time of radio transformation from receiving state to transmitting state, and the time for the radio to sense the carrier. The analysis shows that these parameters are the main factors deteriorating the performance of the protocols, especially for CSMA. The multichannel mode efficiently decreases the effects of these factors and the system capacity is changeable conveniently. Comparing curves and some simulation results are given.
文摘Recently, location-based routings in wireless sensor networks (WSNs) are attracting a lot of interest in the research community, especially because of its scalability. In location-based routing, the network size is scalable without increasing the signalling overhead as routing decisions are inherently localized. Here, each node is aware of its position in the network through some positioning device like GPS and uses this information in the routing mechanism. In this paper, we first discuss the basics of WSNs including the architecture of the network, energy consumption for the components of a typical sensor node, and draw a detailed picture of classification of location-based routing protocols. Then, we present a systematic and comprehensive taxonomy of location-based routing protocols, mostly for sensor networks. All the schemes are subsequently discussed in depth. Finally, we conclude the paper with some insights on potential research directions for location-based routing in WSNs.
基金supported by the National Natural Science Foundation of China (Grant No 60525303)the Natural Science Foundation of Hebei Province,China (Grant No 2006000270)
文摘Nonlinear consensus protocols for dynamic directed networks of multi-agent systems with fixed and switching topologies are investigated separately in this paper. Based on the centre manifold reduction technique, nonlinear consensus protocols are presented. We prove that a group of agents can reach a β-consensus, the value of which is the group decision value varying from the minimum and the maximum values of the initial states of the agents. Moreover, we derive the conditions to guarantee that all the agents reach a β-consensus on a desired group decision value. Finally, a simulation study concerning the vertical alignment manoeuvere of a team of unmanned air vehicles is performed. Simulation results show that the nonlinear consensus protocols proposed are more effective than the linear protocols for the formation control of the agents and they are an improvement over existing protocols.
基金The authors would like to thank DST(SERB),Government of India for grant No.EEQ/2018/000888The work was also supported by the Archimedes Foundation under the Dora plus Grant 11-15/OO/11476We also acknowledge financial support to UoH-IoE by MHRD(F11/9/2019-U3(A)).
文摘The Internet of Things(IoT)has been growing over the past few years due to its flexibility and ease of use in real-time applications.The IoT's foremost task is ensuring that there is proper communication among different types of applications and devices,and that the application layer protocols fulfill this necessity.However,as the number of applications grows,it is necessary to modify or enhance the application layer protocols according to specific IoT applications,allowing specific issues to be addressed,such as dynamic adaption to network conditions and interoperability.Recently,several IoT application layer protocols have been enhanced and modified according to application requirements.However,no existing survey articles focus on these protocols.In this article,we survey traditional and recent advances in IoT application layer protocols,as well as relevant real-time applications and their adapted application layer protocols for improving performance.As changing the nature of protocols for each application is unrealistic,machine learning offers means of making protocols intelligent and is able to adapt dynamically.In this context,we focus on providing open challenges to drive IoT application layer protocols in such a direction.
基金The authors would like to thank the reviewers for their detailed reviews and constructive comments, which have helped improve the quality of this paper. This paper is supported by the National Natural Science Founda- tion of China （No. 61371092）, the Doctoral Fund of Ministry of Education of China （No.20130061120062）, and the China Postdoc- toral Science Foundation （No. 2014M551184）.
文摘Radio frequency identification(RFID) is a new type of non-contact automatic identification technology.Due to its low energy consumption,low cost,and its adaptability to harsh environments,it has been applied to many fields.In the RFID systems,data collision is inevitable when the reader sends a communication request and multiple tags respond with simultaneous data transmission.Data collision is prone to causing problems such as:identification delay,spectrum resource waste,a decreased system throughput rate,etc.Therefore,an efficient,stable anti-collision protocol is crucial for RFID systems.This research analysed the current research into RFID anticollision protocols and summarised means for its improvement through the mechanism of implementation of different types anticollision protocols.Finally,a new direction is proposed for the future development of RFID anti-collision protocol systems.
基金Supported by the National Natural Science Foundation of China(61332019)
文摘Relay attack is one of the most threatening challenges against radio frequency identification（RFID） now. Distance bounding protocols have been introduced to thwart relay attacks. They form a family of challenge-response authentication protocols and confirm the round-trip time at the Rapid Bit Exchange phase. They enable a reader to authenticate and to establish an upper bound on the physical distance to an entrusted tag. We design an effective attack against a family of such protocols to launch the spoofing attacks within effective distance successfully, which demonstrates that existing protocols cannot eliminate such attacks completely. The thesis proposes a new program with time- stamping verification to correct the defect and verify the effectiveness.
基金Project supported in part by the National High Technology Research and Development Program of China (Grant No. 2007AA01Z480)
文摘This paper uses a correlation dimension based nonlinear analysis approach to analyse the dynamics of network traffics with three different application protocols-HTTP, FTP and SMTP. First, the phase space is reconstructed and the embedding parameters are obtained by the mutual information method. Secondly, the correlation dimensions of three different traffics are calculated and the results of analysis have demonstrated that the dynamics of the three different application protocol traffics is different from each other in nature, i.e. HTTP and FTP traffics are chaotic, furthermore, the former is more complex than the later; on the other hand, SMTP traffic is stochastic. It is shown that correlation dimension approach is an efficient method to understand and to characterize the nonlinear dynamics of HTTP, FTP and SMTP protocol network traffics. This analysis provided insight into and a more accurate understanding of nonlinear dynamics of internet traffics which have a complex mixture of chaotic and stochastic components.
文摘From the viewpoint of protocol sequence, analyses are made of the sequence patterns of possible identity authentication protocol under two cases： with or without the trusted third party （TFP）. Ten feasible sequence patterns of authentication protocol with TIP and 5 sequence patterns without TFP are gained. These gained sequence patterns meet the requirements for identity authentication, and basically cover almost all the authentication protocols with TFP and without TFP at present. All of the sequence patterns gained are classified into unilateral or bilateral authentication. Then, according to the sequence symmetry, several good sequence patterns with TFP are evaluated. The accompolished results can provide a reference to design of new identity authentication protocols.
基金National Natural Science Foundations of China(Nos.60872073,6097501,and 51075068)the Doctoral Fund of Ministry of Education of China(No.20110092130004)the Research Foundation and Education Bureau of Anhui Province of China(No.KJ2009B137)
文摘Medium access control( MAC) protocol of underwater acoustic communication network is a key technology for underwater acoustic networks( UANs). Most of the MAC protocols for wireless terrestrial communication networks have been designed with negligible propagation delay. If it is deployed directly in an underwater environment,the UANs will perform inefficiently. In this paper,the characteristics of underwater acoustic channel are modeled and simulated by using the OPNET simulation tool,which are the speed of sound, propagation loss, and four sources for ambient noise: the turbulence,shipping,wind driven waves and thermal noise. The performance of pure Aloha( P-Aloha),carrier sense multiple access with collision avoidance( CSMA / CA) and multiple access collision avoidance for wireless local area network( MACAW) protocols in underwater acoustic channel environment are evaluated. The different performance of protocols in underwater environment is compared in the simulation.
基金National High Technical Research and Development Program of China(863 program)under Grant No. 2007AA01Z471
文摘Provable security has become a popular approach for analyzing the security of cryptographic protocols.However,writing and verifying proofs by hand are prone to errors.This paper advocates the automatic security proof framework with sequences of games.We make slight modifications to Blanchet's calculus to make it easy for parsing the initial game.The main contribution of this work is that it introduces algebraic properties with observational equivalences to automatic security proofs,and thus can deal with some practical cryptographic schemes with hard problems.We illustrate the use of algebraic properties in the framework by proving the semantic security of the ElGamal encryption scheme.
