Objective:To evaluate the efficacy and safety of acupoint application for post-stroke depression(PSD)by regulating gastrointestinal function.A secondary objective is to explore the potential mechanism underlying this ...Objective:To evaluate the efficacy and safety of acupoint application for post-stroke depression(PSD)by regulating gastrointestinal function.A secondary objective is to explore the potential mechanism underlying this approach from the perspective of gut microbiota.Methods:This multicenter,randomized,double-blind(patients and assessors),placebo-controlled trial will enroll 80 patients with PSD,and include a 1-week run-in period,a 4-week treatment phase,and a 12-week follow-up.Eligible participants will randomly be assigned in a 1:1 ratio to either the acupoint application or placebo(non-acupoint)groups.Treatments will be administered thrice weekly for 4 weeks.The primary outcome is change in the Hamilton Rating Scale for Depression(HAMD)score.Secondary outcomes include the Beck Depression Inventory(BDI),36-Item Short-Form Health Survey(SF-36),Barthel Index of Activities of Daily Living,Social Adaptation Self-Evaluation Scale(SASS),and gut microbiota profiling.All outcomes will be assessed at baseline(prior to treatment),during treatment(weeks 2 and 4),and during follow-up(weeks 8,12,and 16).The Treatment Emergent Symptom Scale(TESS)will be used for evaluation throughout the 4-week treatment phase.Discussion:The results of this study will provide important evidence supporting a novel treatment strategy for PSD that targets gastrointestinal regulation,potentially informing future clinical practice.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
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
Fixture design and planning is one of the most important manufacturing activities, playing a pivotal role in deciding the lead time for product development. Fixture design, which affects the part-quality in terms of g...Fixture design and planning is one of the most important manufacturing activities, playing a pivotal role in deciding the lead time for product development. Fixture design, which affects the part-quality in terms of geometric accuracy and surface finish, can be enhanced by using the product manufacturing information(PMI) stored in the neutral standard for the exchange of product model data(STEP) file, thereby integrating design and manufacturing. The present paper proposes a unique fixture design approach, to extract the geometry information from STEP application protocol(AP) 242 files of computer aided design(CAD) models, for providing automatic suggestions of locator positions and clamping surfaces. Automatic feature extraction software "FiXplan", developed using the programming language C#, is used to extract the part feature, dimension and geometry information. The information from the STEP AP 242 file is deduced using geometric reasoning techniques, which in turn is utilized for fixture planning. The developed software is observed to be adept in identifying the primary, secondary, and tertiary locating faces and locator position configurations of prismatic components. Structural analysis of the prismatic part under different locator positions was performed using commercial finite element method software, ABAQUS, and the optimized locator position was identified on the basis of minimum deformation of the workpiece.The area-ratio(base locator enclosed area(%)/work piece base area(%)) for the ideal locator configuration was observed as 33%. Experiments were conducted on a prismatic workpiece using a specially designed fixture, for different locator configurations. The surface roughness and waviness of the machined surfaces were analysed using an Alicona non-contact optical profilometer. The best surface characteristics were obtained for the surface machined under the ideal locator positions having an area-ratio of 33%, thus validating the predicted numerical results. The efficiency, capability and applicability of the developed software is demonstrated for the finishing operation of a sensor cover – a typical prismatic component having applications in the naval industry, under different locator configurations.The best results were obtained under the proposed ideal locator configuration of area-ratio 33%.展开更多
In modern wireless communication network, the increased consumer demands for multi-type applications and high quality services have become a prominent trend, and put considerable pressure on the wireless network. In t...In modern wireless communication network, the increased consumer demands for multi-type applications and high quality services have become a prominent trend, and put considerable pressure on the wireless network. In that case, the Quality of Experience(Qo E) has received much attention and has become a key performance measurement for the application and service. In order to meet the users' expectations, the management of the resource is crucial in wireless network, especially the Qo E based resource allocation. One of the effective way for resource allocation management is accurate application identification. In this paper, we propose a novel deep learning based method for application identification. We first analyse the requirement of managing Qo E for wireless communication, and review the limitation of the traditional identification methods. After that, a deep learning based method is proposed for automatically extracting the features and identifying the type of application. The proposed method is evaluated by using the practical wireless traffic data, and the experiments verify the effectiveness of our method.展开更多
Think-aloud protocols have drawn much attention over the past two decades.Given the expanse of the relevant literature,we narrow our focus on core papers on the application of this research method to EFL education res...Think-aloud protocols have drawn much attention over the past two decades.Given the expanse of the relevant literature,we narrow our focus on core papers on the application of this research method to EFL education research in China in the past 25 years,aiming to summarize the achievements of its application to EFL education rescarch and discover the problems in the current rescarch.In this systematic review,a total of 53 articles are retrieved.Adopting the methodologial synthesis,we analyze the artidles from the perspectives of the research trend,research arcas,rescarch design,data collection,data analysis,and presentation of results.It is found that the overall number of studies using think-aloud in EFL education is insufficient.The research using think aloud in EFL writing accounts for the highest proportion,while few studies on EFL listening and speaking via this research method are conducted.Tertiary-level students are the most popular participants in the studies using think aloud protocols.In addition,the descriptions of the data collection and data analysis processes are insuficient.Based on these findings,implications for teachers,curriculum designers,and researchers in EFL education are further discussed.展开更多
Greenhouse farming is considered one of the precision and sustainable forms of smart agriculture.Although greenhouse gases can support off-season crops inside the indoor environment,monitoring,controlling,and managing...Greenhouse farming is considered one of the precision and sustainable forms of smart agriculture.Although greenhouse gases can support off-season crops inside the indoor environment,monitoring,controlling,and managing crop parameters at greenhouse farms more precisely and securely is necessary,even in harsh climate regions.The evolving Internet of Things(IoT)technologies,including smart sensors,devices,network topologies,big data analytics,and intelligent decision-making,are thought to be the solution for automating greenhouse farming parameters like internal atmosphere control,irrigation control,crop growth monitoring,and so on.This paper introduces a comprehensive survey of recent advances in IoT-based greenhouse farming.We summarize the related review articles.The classification of greenhouse farming based on IoT(smart greenhouse,hydroponics greenhouse,and vertical farming)is introduced.Also,we present a detailed architecture for the components of greenhouse agriculture applications based on IoT,including physical devices,communication protocols,and cloud/fog computing technologies.We also present a classification of IoT applications of greenhouse farming,including monitoring,controlling,tracking,and predicting.Furthermore,we present the technical and resource management challenges for optimal greenhouse farming.Moreover,countries already applying IoT in greenhouse farming have been presented.Lastly,future suggestions related to IoT-based greenhouse farming have been introduced.展开更多
Distributed speech recognition (DSR) applications have certain QoS (Quality of service) requirements in terms of latency, packet loss rate, etc. To deliver quality guaranteed DSR application over wirelined or wireless...Distributed speech recognition (DSR) applications have certain QoS (Quality of service) requirements in terms of latency, packet loss rate, etc. To deliver quality guaranteed DSR application over wirelined or wireless links, some QoS mechanisms should be provided. We put forward a RTP/RSVP transmission scheme with DSR-specific payload and QoS parameters by modifying the present WAP protocol stack. The simulation result shows that this scheme will provide adequate network bandwidth to keep the real-time transport of DSR data over either wirelined or wireless channels.展开更多
The wireless application protocol （WAP） protocol is now the leading standard for information services on wireless terminals like digital mobile phones. By the use of WAP, wireless devices, like mobile phones, are po...The wireless application protocol （WAP） protocol is now the leading standard for information services on wireless terminals like digital mobile phones. By the use of WAP, wireless devices, like mobile phones, are possibly infected with virus and worms. Though up to now there is no such attack, as the usage of script languages increases, there is a chance of malicious code injection. This paper discusses the threats with current WAP protocol, and how changes in the protocol and the increase in its usage will enable entry of real viruses. Future threat scenarios are presented along with suggestions to avoid these problems.展开更多
Parabiosis is a surgical method of animal modeling with a long history.It has been widely used in medical research,particularly in the fields of aging,stem cells,neuroscience,and immunity in the past two decades.The p...Parabiosis is a surgical method of animal modeling with a long history.It has been widely used in medical research,particularly in the fields of aging,stem cells,neuroscience,and immunity in the past two decades.The protocols for parabiosis have been improved many times and are now widely accepted.However,researchers need to consider many details,from surgical operation to perioperative management,to reduce mortality and maintain the parabiosis union.Although parabiosis has certain inevitable limitations,it still has broad application prospects as an irreplaceable animal model in the medical research field.展开更多
Cognitive Radio Networks(CRNs)have become a successful platform in recent years for a diverse range of future systems,in particularly,industrial internet of things(IIoT)applications.In order to provide an efficient co...Cognitive Radio Networks(CRNs)have become a successful platform in recent years for a diverse range of future systems,in particularly,industrial internet of things(IIoT)applications.In order to provide an efficient connection among IIoT devices,CRNs enhance spectrum utilization by using licensed spectrum.However,the routing protocol in these networks is considered one of the main problems due to node mobility and time-variant channel selection.Specifically,the channel selection for routing protocol is indispensable in CRNs to provide an adequate adaptation to the Primary User(PU)activity and create a robust routing path.This study aims to construct a robust routing path by minimizing PU interference and routing delay to maximize throughput within the IIoT domain.Thus,a generic routing framework from a cross-layer perspective is investigated that intends to share the information resources by exploiting a recently proposed method,namely,Channel Availability Probability.Moreover,a novel cross-layer-oriented routing protocol is proposed by using a time-variant channel estimation technique.This protocol combines lower layer(Physical layer and Data Link layer)sensing that is derived from the channel estimation model.Also,it periodically updates and stores the routing table for optimal route decision-making.Moreover,in order to achieve higher throughput and lower delay,a new routing metric is presented.To evaluate the performance of the proposed protocol,network simulations have been conducted and also compared to the widely used routing protocols,as a benchmark.The simulation results of different routing scenarios demonstrate that our proposed solution outperforms the existing protocols in terms of the standard network performance metrics involving packet delivery ratio(with an improved margin of around 5–20%approximately)under varying numbers of PUs and cognitive users in Mobile Cognitive Radio Networks(MCRNs).Moreover,the cross-layer routing protocol successfully achieves high routing performance in finding a robust route,selecting the high channel stability,and reducing the probability of PU interference for continued communication.展开更多
This paper deals with the proposal of a new model based on Agent Petri Nets (APN) to specify interactions among agents in Multi Agents System (MAS). Indeed, an agent approach requires a powerful and expressive formali...This paper deals with the proposal of a new model based on Agent Petri Nets (APN) to specify interactions among agents in Multi Agents System (MAS). Indeed, an agent approach requires a powerful and expressive formalism that allows him to model the behavior of a set of agents that interact. We are modeling some variants of FIPA standard protocols. Our Models are found based on communicating cognitive agents. Each Agent is capable of perceiving their environment partly and building, sending and receiving messages.展开更多
The modeling of Application Triggering Architecture （ATA） in the IP Multimedia Sub- system （IMS） is presented. The session setup delay and system throughput are employed as the measurement to investigate the perfo...The modeling of Application Triggering Architecture （ATA） in the IP Multimedia Sub- system （IMS） is presented. The session setup delay and system throughput are employed as the measurement to investigate the performance of ATA and the Serving Call Session Control Punction （S-CSCF）. With theoretical analysis and simulation results, we find that, the number of the ASs （Application Servers）, the use of the subsequent Filter Criteria （sFC） and the arrival rate have heavy impact on the session setup delay and the S-CSCF is the major bottleneck in IMS network. The results are useful in constructing IMS network. At last, we propose several possible solutions to reduce the session setup delay and decrease the load of the S-CSCF.展开更多
In data centers, the transmission control protocol(TCP) incast causes catastrophic goodput degradation to applications with a many-to-one traffic pattern. In this paper, we intend to tame incast at the receiver-side a...In data centers, the transmission control protocol(TCP) incast causes catastrophic goodput degradation to applications with a many-to-one traffic pattern. In this paper, we intend to tame incast at the receiver-side application. Towards this goal, we first develop an analytical model that formulates the incast probability as a function of connection variables and network environment settings. We combine the model with the optimization theory and derive some insights into minimizing the incast probability through tuning connection variables related to applications. Then,enlightened by the analytical results, we propose an adaptive application-layer solution to the TCP incast.The solution equally allocates advertised windows to concurrent connections, and dynamically adapts the number of concurrent connections to the varying conditions. Simulation results show that our solution consistently eludes incast and achieves high goodput in various scenarios including the ones with multiple bottleneck links and background TCP traffic.展开更多
基金supported by the Chinese Medicine Development Fund,Hong Kong SAR,China(23B2/027A_R1)the National Natural Science Foundation of China(81704198).
文摘Objective:To evaluate the efficacy and safety of acupoint application for post-stroke depression(PSD)by regulating gastrointestinal function.A secondary objective is to explore the potential mechanism underlying this approach from the perspective of gut microbiota.Methods:This multicenter,randomized,double-blind(patients and assessors),placebo-controlled trial will enroll 80 patients with PSD,and include a 1-week run-in period,a 4-week treatment phase,and a 12-week follow-up.Eligible participants will randomly be assigned in a 1:1 ratio to either the acupoint application or placebo(non-acupoint)groups.Treatments will be administered thrice weekly for 4 weeks.The primary outcome is change in the Hamilton Rating Scale for Depression(HAMD)score.Secondary outcomes include the Beck Depression Inventory(BDI),36-Item Short-Form Health Survey(SF-36),Barthel Index of Activities of Daily Living,Social Adaptation Self-Evaluation Scale(SASS),and gut microbiota profiling.All outcomes will be assessed at baseline(prior to treatment),during treatment(weeks 2 and 4),and during follow-up(weeks 8,12,and 16).The Treatment Emergent Symptom Scale(TESS)will be used for evaluation throughout the 4-week treatment phase.Discussion:The results of this study will provide important evidence supporting a novel treatment strategy for PSD that targets gastrointestinal regulation,potentially informing future clinical practice.
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.
基金Department of Science and Technology,Government of India for providing financial support under the scheme FIST(No.SR/FST/ETI-388/2015)。
文摘Fixture design and planning is one of the most important manufacturing activities, playing a pivotal role in deciding the lead time for product development. Fixture design, which affects the part-quality in terms of geometric accuracy and surface finish, can be enhanced by using the product manufacturing information(PMI) stored in the neutral standard for the exchange of product model data(STEP) file, thereby integrating design and manufacturing. The present paper proposes a unique fixture design approach, to extract the geometry information from STEP application protocol(AP) 242 files of computer aided design(CAD) models, for providing automatic suggestions of locator positions and clamping surfaces. Automatic feature extraction software "FiXplan", developed using the programming language C#, is used to extract the part feature, dimension and geometry information. The information from the STEP AP 242 file is deduced using geometric reasoning techniques, which in turn is utilized for fixture planning. The developed software is observed to be adept in identifying the primary, secondary, and tertiary locating faces and locator position configurations of prismatic components. Structural analysis of the prismatic part under different locator positions was performed using commercial finite element method software, ABAQUS, and the optimized locator position was identified on the basis of minimum deformation of the workpiece.The area-ratio(base locator enclosed area(%)/work piece base area(%)) for the ideal locator configuration was observed as 33%. Experiments were conducted on a prismatic workpiece using a specially designed fixture, for different locator configurations. The surface roughness and waviness of the machined surfaces were analysed using an Alicona non-contact optical profilometer. The best surface characteristics were obtained for the surface machined under the ideal locator positions having an area-ratio of 33%, thus validating the predicted numerical results. The efficiency, capability and applicability of the developed software is demonstrated for the finishing operation of a sensor cover – a typical prismatic component having applications in the naval industry, under different locator configurations.The best results were obtained under the proposed ideal locator configuration of area-ratio 33%.
基金supported by NSAF under Grant(No.U1530117)National Natural Science Foundation of China(No.61471022 and No.61201156)
文摘In modern wireless communication network, the increased consumer demands for multi-type applications and high quality services have become a prominent trend, and put considerable pressure on the wireless network. In that case, the Quality of Experience(Qo E) has received much attention and has become a key performance measurement for the application and service. In order to meet the users' expectations, the management of the resource is crucial in wireless network, especially the Qo E based resource allocation. One of the effective way for resource allocation management is accurate application identification. In this paper, we propose a novel deep learning based method for application identification. We first analyse the requirement of managing Qo E for wireless communication, and review the limitation of the traditional identification methods. After that, a deep learning based method is proposed for automatically extracting the features and identifying the type of application. The proposed method is evaluated by using the practical wireless traffic data, and the experiments verify the effectiveness of our method.
文摘Think-aloud protocols have drawn much attention over the past two decades.Given the expanse of the relevant literature,we narrow our focus on core papers on the application of this research method to EFL education research in China in the past 25 years,aiming to summarize the achievements of its application to EFL education rescarch and discover the problems in the current rescarch.In this systematic review,a total of 53 articles are retrieved.Adopting the methodologial synthesis,we analyze the artidles from the perspectives of the research trend,research arcas,rescarch design,data collection,data analysis,and presentation of results.It is found that the overall number of studies using think-aloud in EFL education is insufficient.The research using think aloud in EFL writing accounts for the highest proportion,while few studies on EFL listening and speaking via this research method are conducted.Tertiary-level students are the most popular participants in the studies using think aloud protocols.In addition,the descriptions of the data collection and data analysis processes are insuficient.Based on these findings,implications for teachers,curriculum designers,and researchers in EFL education are further discussed.
文摘Greenhouse farming is considered one of the precision and sustainable forms of smart agriculture.Although greenhouse gases can support off-season crops inside the indoor environment,monitoring,controlling,and managing crop parameters at greenhouse farms more precisely and securely is necessary,even in harsh climate regions.The evolving Internet of Things(IoT)technologies,including smart sensors,devices,network topologies,big data analytics,and intelligent decision-making,are thought to be the solution for automating greenhouse farming parameters like internal atmosphere control,irrigation control,crop growth monitoring,and so on.This paper introduces a comprehensive survey of recent advances in IoT-based greenhouse farming.We summarize the related review articles.The classification of greenhouse farming based on IoT(smart greenhouse,hydroponics greenhouse,and vertical farming)is introduced.Also,we present a detailed architecture for the components of greenhouse agriculture applications based on IoT,including physical devices,communication protocols,and cloud/fog computing technologies.We also present a classification of IoT applications of greenhouse farming,including monitoring,controlling,tracking,and predicting.Furthermore,we present the technical and resource management challenges for optimal greenhouse farming.Moreover,countries already applying IoT in greenhouse farming have been presented.Lastly,future suggestions related to IoT-based greenhouse farming have been introduced.
文摘Distributed speech recognition (DSR) applications have certain QoS (Quality of service) requirements in terms of latency, packet loss rate, etc. To deliver quality guaranteed DSR application over wirelined or wireless links, some QoS mechanisms should be provided. We put forward a RTP/RSVP transmission scheme with DSR-specific payload and QoS parameters by modifying the present WAP protocol stack. The simulation result shows that this scheme will provide adequate network bandwidth to keep the real-time transport of DSR data over either wirelined or wireless channels.
文摘The wireless application protocol （WAP） protocol is now the leading standard for information services on wireless terminals like digital mobile phones. By the use of WAP, wireless devices, like mobile phones, are possibly infected with virus and worms. Though up to now there is no such attack, as the usage of script languages increases, there is a chance of malicious code injection. This paper discusses the threats with current WAP protocol, and how changes in the protocol and the increase in its usage will enable entry of real viruses. Future threat scenarios are presented along with suggestions to avoid these problems.
基金This study was supported by the National Natural Science Foundation of China(81601112,81801090)Top Project of Youth Incubation Program of Military Medical Science and Technology(19QNP065)+1 种基金Sichuan Department of Science and Technology Fund(2018SZ0141,2019YSF0213)China’s Post-doctoral Science Fund(2017M623357),and Sichuan Medical Association Fund(Q17008)。
文摘Parabiosis is a surgical method of animal modeling with a long history.It has been widely used in medical research,particularly in the fields of aging,stem cells,neuroscience,and immunity in the past two decades.The protocols for parabiosis have been improved many times and are now widely accepted.However,researchers need to consider many details,from surgical operation to perioperative management,to reduce mortality and maintain the parabiosis union.Although parabiosis has certain inevitable limitations,it still has broad application prospects as an irreplaceable animal model in the medical research field.
文摘Cognitive Radio Networks(CRNs)have become a successful platform in recent years for a diverse range of future systems,in particularly,industrial internet of things(IIoT)applications.In order to provide an efficient connection among IIoT devices,CRNs enhance spectrum utilization by using licensed spectrum.However,the routing protocol in these networks is considered one of the main problems due to node mobility and time-variant channel selection.Specifically,the channel selection for routing protocol is indispensable in CRNs to provide an adequate adaptation to the Primary User(PU)activity and create a robust routing path.This study aims to construct a robust routing path by minimizing PU interference and routing delay to maximize throughput within the IIoT domain.Thus,a generic routing framework from a cross-layer perspective is investigated that intends to share the information resources by exploiting a recently proposed method,namely,Channel Availability Probability.Moreover,a novel cross-layer-oriented routing protocol is proposed by using a time-variant channel estimation technique.This protocol combines lower layer(Physical layer and Data Link layer)sensing that is derived from the channel estimation model.Also,it periodically updates and stores the routing table for optimal route decision-making.Moreover,in order to achieve higher throughput and lower delay,a new routing metric is presented.To evaluate the performance of the proposed protocol,network simulations have been conducted and also compared to the widely used routing protocols,as a benchmark.The simulation results of different routing scenarios demonstrate that our proposed solution outperforms the existing protocols in terms of the standard network performance metrics involving packet delivery ratio(with an improved margin of around 5–20%approximately)under varying numbers of PUs and cognitive users in Mobile Cognitive Radio Networks(MCRNs).Moreover,the cross-layer routing protocol successfully achieves high routing performance in finding a robust route,selecting the high channel stability,and reducing the probability of PU interference for continued communication.
文摘This paper deals with the proposal of a new model based on Agent Petri Nets (APN) to specify interactions among agents in Multi Agents System (MAS). Indeed, an agent approach requires a powerful and expressive formalism that allows him to model the behavior of a set of agents that interact. We are modeling some variants of FIPA standard protocols. Our Models are found based on communicating cognitive agents. Each Agent is capable of perceiving their environment partly and building, sending and receiving messages.
基金Supported by the National Science Fund for Distinguished Young Scholars (No.60525110)the National 973 Program (No.2007CB307100, 2007CB307103)+2 种基金the Program for New Century Excellent Talents in University (No. NCET-04-0111)the Development Fund Project for Electronic and Information Industry (Mobile Service and Application System Based on 3G)the National Spe-cific Project for Hi-Tech Industrialization and Information Equipments (Mobile Intelligent Network Supporting Value-added Data Services)
文摘The modeling of Application Triggering Architecture （ATA） in the IP Multimedia Sub- system （IMS） is presented. The session setup delay and system throughput are employed as the measurement to investigate the performance of ATA and the Serving Call Session Control Punction （S-CSCF）. With theoretical analysis and simulation results, we find that, the number of the ASs （Application Servers）, the use of the subsequent Filter Criteria （sFC） and the arrival rate have heavy impact on the session setup delay and the S-CSCF is the major bottleneck in IMS network. The results are useful in constructing IMS network. At last, we propose several possible solutions to reduce the session setup delay and decrease the load of the S-CSCF.
基金supported by the Fundamental Research Fundsfor the Central Universities under Grant No.ZYGX2015J009the Sichuan Province Scientific and Technological Support Project under Grants No.2014GZ0017 and No.2016GZ0093
文摘In data centers, the transmission control protocol(TCP) incast causes catastrophic goodput degradation to applications with a many-to-one traffic pattern. In this paper, we intend to tame incast at the receiver-side application. Towards this goal, we first develop an analytical model that formulates the incast probability as a function of connection variables and network environment settings. We combine the model with the optimization theory and derive some insights into minimizing the incast probability through tuning connection variables related to applications. Then,enlightened by the analytical results, we propose an adaptive application-layer solution to the TCP incast.The solution equally allocates advertised windows to concurrent connections, and dynamically adapts the number of concurrent connections to the varying conditions. Simulation results show that our solution consistently eludes incast and achieves high goodput in various scenarios including the ones with multiple bottleneck links and background TCP traffic.
