Wireless Body Area Network(WBAN)technologies are emerging with extensive applications in several domains.Health is a fascinating domain of WBAN for smart monitoring of a patient’s condition.An important factor to con...Wireless Body Area Network(WBAN)technologies are emerging with extensive applications in several domains.Health is a fascinating domain of WBAN for smart monitoring of a patient’s condition.An important factor to consider in WBAN is a node’s lifetime.Improving the lifetime of nodes is critical to address many issues,such as utility and reliability.Existing routing protocols have addressed the energy conservation problem but considered only a few parameters,thus affecting their performance.Moreover,most of the existing schemes did not consider traffic prioritization which is critical in WBANs.In this paper,an adaptive multi-cost routing protocol is proposed with a multi-objective cost function considering minimum distance from sink,temperature of sensor nodes,priority of sensed data,and maximum residual energy on sensor nodes.The performance of the proposed protocol is compared with the existing schemes for the parameters:network lifetime,stability period,throughput,energy consumption,and path loss.It is evident from the obtained results that the proposed protocol improves network lifetime and stability period by 30%and 15%,respectively,as well as outperforms the existing protocols in terms of throughput,energy consumption,and path loss.展开更多
There is an increasing demand for supporting high-quality real-time audiovisual services for the next generation wired and wireless networks. However, due to variety of bandwidths of different networks, it is a great ...There is an increasing demand for supporting high-quality real-time audiovisual services for the next generation wired and wireless networks. However, due to variety of bandwidths of different networks, it is a great challenge for deployment. In this paper, a novel high-definition (HD) video transmission system was proposed which depends upon reliable compound multicast protocols and QoS control over the various kinds of networks. This system detects client's network condition and assigns it to a proper proxy. Each proxy is capable of detecting network parameters and adaptively tuning such transport parameters as bit rate, video resolution, frame rate and QoS mechanisms to this condition. It also provides FEC error recovery under consideration of characteristics of MPEG4 video codec. Our simulation demonstrates that different network clients such as ADSL, CERNET, and CERNET2 can receive more video reliability with less delay.展开更多
On the basis of studying the standard TCP retransmission mechanism, this paper proposes a method to adopt the theory of adaptive filtering in the field for the estimation of round trip time （RTT）. Then this method i...On the basis of studying the standard TCP retransmission mechanism, this paper proposes a method to adopt the theory of adaptive filtering in the field for the estimation of round trip time （RTT）. Then this method is embedded in TCP for estimation of RTT, and defined as RTT-AF TCP. In the schemes with Only-TCP flow and with TCP and UDP flow fighting for the link, the experiment results were made and analyzed by using the standard TCP and the RTT-AF TCP. The experimental results show higher throughput and lower loss rate of packets by using RTT-AF TCP for data transmission, and achieve excellent effect.展开更多
【目的】工业控制系统(industrial control system,ICS)中设备间通信过程高度依赖工控协议来实现,协议安全性对保障ICS稳定运行起到关键作用。漏洞挖掘与入侵检测等作为ICS安全防御体系的核心技术组件,其有效性依赖于对工控协议结构及...【目的】工业控制系统(industrial control system,ICS)中设备间通信过程高度依赖工控协议来实现,协议安全性对保障ICS稳定运行起到关键作用。漏洞挖掘与入侵检测等作为ICS安全防御体系的核心技术组件,其有效性依赖于对工控协议结构及语义功能的精确解析。协议逆向分析作为解析协议结构与语义功能的关键技术,其核心环节语义推断精度直接决定协议理解的准确性。然而,受限于工控协议文档缺失、格式异构性强等现实条件,现有语义推断方法普遍依赖专家经验,存在自动化水平不足、跨协议泛化性能有限等固有瓶颈,难以适应实际工业环境中多源异构协议的高精度解析需求。【方法】为解决上述问题,本文提出mBERT协同多源领域自适应与结构化掩码策略的语义推断方法。通过mBERT模型实现跨协议通用语义表示;利用结合注意力权重与位置编码设计的结构化掩码策略,增强模型对协议结构和语义内在联系的表示能力,提高语义推断方法的自动化程度和效率;利用结合对抗训练的多源领域自适应逐步微调策略,提升模型对多个源协议的语义通用表示能力,增强其在多种工控协议上的适用性,实现关键字语义的有效推断。【结果】在辽宁省石油化工行业信息安全重点实验室的典型能源企业攻防演练靶场中开展实验验证,采集了S7comm、Modbus/TCP和EtherNet/IP三种工控协议数据,并利用协议复杂度评分机制组建训练数据集。结果表明,多源领域自适应逐步微调策略能够显著提升模型性能,将其与结构化掩码策略结合,进一步提高了语义推断精度,且本文方法在精确度、召回率与F_(1)分数指标上均显著优于现有基线方法。【结论】本文提出了mBERT协同多源领域自适应与结构化掩码策略的语义推断方法,在语义推断中采用高维球面映射与多任务损失函数,增强了不同语义类别的区分度与模型对协议语义的深层辨识能力。本文方法不仅显著降低了对人工先验知识的依赖,也提升了语义推断效率与跨协议适用性,为工控协议逆向分析及工业系统安全防护提供了具备理论支撑的新路径。展开更多
In this paper,an adaptive dynamic programming(ADP)strategy is investigated for discrete-time nonlinear systems with unknown nonlinear dynamics subject to input saturation.To save the communication resources between th...In this paper,an adaptive dynamic programming(ADP)strategy is investigated for discrete-time nonlinear systems with unknown nonlinear dynamics subject to input saturation.To save the communication resources between the controller and the actuators,stochastic communication protocols(SCPs)are adopted to schedule the control signal,and therefore the closed-loop system is essentially a protocol-induced switching system.A neural network(NN)-based identifier with a robust term is exploited for approximating the unknown nonlinear system,and a set of switch-based updating rules with an additional tunable parameter of NN weights are developed with the help of the gradient descent.By virtue of a novel Lyapunov function,a sufficient condition is proposed to achieve the stability of both system identification errors and the update dynamics of NN weights.Then,a value iterative ADP algorithm in an offline way is proposed to solve the optimal control of protocol-induced switching systems with saturation constraints,and the convergence is profoundly discussed in light of mathematical induction.Furthermore,an actor-critic NN scheme is developed to approximate the control law and the proposed performance index function in the framework of ADP,and the stability of the closed-loop system is analyzed in view of the Lyapunov theory.Finally,the numerical simulation results are presented to demonstrate the effectiveness of the proposed control scheme.展开更多
Considering that weak channel collision detection ability, long propagation delay and heavy load in LEO satellite communications, a valid adaptive APRMA MAC protocol was proposed. Different access probability function...Considering that weak channel collision detection ability, long propagation delay and heavy load in LEO satellite communications, a valid adaptive APRMA MAC protocol was proposed. Different access probability functions for different services were obtained and appropriate access probabilities for voice and data users were updated slot by slot based on the estimation of the voice traffic and the channel status. In the proposed MAC protocol limited wireless resource is allocated reasonably by multiple users and high capacity was achieved. Three performance parameters: voice packet loss probability, average delay of data packets and throughput of data packets were considered in simulation. Finally simulation results demonstrated that the performance of system was improved by the APRMA compared with the conventional PRMA, with an acceptable trade-off between QoS of voice and delay of data.展开更多
Background: The importance of adapting evidence-based health interventions to enhance their congruence with the beliefs of ethno-cultural communities is well recognized. Although a systematic cultural adaptation proce...Background: The importance of adapting evidence-based health interventions to enhance their congruence with the beliefs of ethno-cultural communities is well recognized. Although a systematic cultural adaptation process is available, it lacks specific instructions on how to adapt interventions so that they are aligned with cultural beliefs. In this paper, we present an integrated strategy that operationalizes the adaptation process by describing specific practical instructions on how to align interventions with cultural beliefs. Methods: The strategy integrates concept and intervention mapping, and uses mixed methods for gathering data from community representatives. The data pertain to a community’s cultural beliefs and values related to a health problem, acceptability of evidence-based interventions targeting the problem, and aspects of the interventions that should be modified to enhance their fit with cultural beliefs. A step-by-step protocol is described to guide application of the integrated strategy for cultural adaptation. Conclusions: The strength of the integrated strategy relies on the use of concept and intervention mapping approaches for specifying a step-by-step protocol to actively engage community representatives in the cultural adaptation of interventions. Future research should evaluate the utility of this strategy.展开更多
Compatibility is the precondition to ensure the correct interaction among components in composition process, how to make the mismatch components coordinate correctly is a vital problem in component composition. This p...Compatibility is the precondition to ensure the correct interaction among components in composition process, how to make the mismatch components coordinate correctly is a vital problem in component composition. This paper first modeled component behavior by LTS and expressed action mapping as synchronous vector then defined the sequential relationship among synchronous vectors as adaptation contract. Thirdly we analyzed the different mismatch situations and corresponding adaptation strategies. At last designed adaptation algorithm to produce adaptor specification automatically and ensured the mismatch components can correct interaction under the mediation of adaptor and verified the validity of proposed method through an application system.展开更多
This paper presents adaptive hybrid protocols based on the declarative network and mainly discusses the principle and realization of the Bayesian-estimation based adaptive hybrid protocol in the declarative network, w...This paper presents adaptive hybrid protocols based on the declarative network and mainly discusses the principle and realization of the Bayesian-estimation based adaptive hybrid protocol in the declarative network, which is well adapted to the Mobile Ad hoc NETwork (MANET). The adaptive hybrid protocol is designed for ad hoc networks which have characteristics like self-organizing, no trusted party, flexibility, etc. The nodes that run the hybrid protocol can automatically select one routing protocol that is suitable for different network environment. The Bayesian-estimation based adaptive strategy, that improves the adaptability and stability of the protocol, succeeds in the Rapidnet, a declarative network engine. The result in the Rapidnet proves that the hybrid protocol and the adaptive strategy are feasible. The experiment on the ns-3 simulator, an emerging discrete-event network simulator, validates that this protocol performs well and reduces communication overheads.展开更多
文摘Wireless Body Area Network(WBAN)technologies are emerging with extensive applications in several domains.Health is a fascinating domain of WBAN for smart monitoring of a patient’s condition.An important factor to consider in WBAN is a node’s lifetime.Improving the lifetime of nodes is critical to address many issues,such as utility and reliability.Existing routing protocols have addressed the energy conservation problem but considered only a few parameters,thus affecting their performance.Moreover,most of the existing schemes did not consider traffic prioritization which is critical in WBANs.In this paper,an adaptive multi-cost routing protocol is proposed with a multi-objective cost function considering minimum distance from sink,temperature of sensor nodes,priority of sensed data,and maximum residual energy on sensor nodes.The performance of the proposed protocol is compared with the existing schemes for the parameters:network lifetime,stability period,throughput,energy consumption,and path loss.It is evident from the obtained results that the proposed protocol improves network lifetime and stability period by 30%and 15%,respectively,as well as outperforms the existing protocols in terms of throughput,energy consumption,and path loss.
文摘There is an increasing demand for supporting high-quality real-time audiovisual services for the next generation wired and wireless networks. However, due to variety of bandwidths of different networks, it is a great challenge for deployment. In this paper, a novel high-definition (HD) video transmission system was proposed which depends upon reliable compound multicast protocols and QoS control over the various kinds of networks. This system detects client's network condition and assigns it to a proper proxy. Each proxy is capable of detecting network parameters and adaptively tuning such transport parameters as bit rate, video resolution, frame rate and QoS mechanisms to this condition. It also provides FEC error recovery under consideration of characteristics of MPEG4 video codec. Our simulation demonstrates that different network clients such as ADSL, CERNET, and CERNET2 can receive more video reliability with less delay.
基金Supported by the National Natural Science Foundation of China （No. 60775058） the Key Project of Ministry of Education of China （No. 107028）.
文摘On the basis of studying the standard TCP retransmission mechanism, this paper proposes a method to adopt the theory of adaptive filtering in the field for the estimation of round trip time （RTT）. Then this method is embedded in TCP for estimation of RTT, and defined as RTT-AF TCP. In the schemes with Only-TCP flow and with TCP and UDP flow fighting for the link, the experiment results were made and analyzed by using the standard TCP and the RTT-AF TCP. The experimental results show higher throughput and lower loss rate of packets by using RTT-AF TCP for data transmission, and achieve excellent effect.
文摘【目的】工业控制系统(industrial control system,ICS)中设备间通信过程高度依赖工控协议来实现,协议安全性对保障ICS稳定运行起到关键作用。漏洞挖掘与入侵检测等作为ICS安全防御体系的核心技术组件,其有效性依赖于对工控协议结构及语义功能的精确解析。协议逆向分析作为解析协议结构与语义功能的关键技术,其核心环节语义推断精度直接决定协议理解的准确性。然而,受限于工控协议文档缺失、格式异构性强等现实条件,现有语义推断方法普遍依赖专家经验,存在自动化水平不足、跨协议泛化性能有限等固有瓶颈,难以适应实际工业环境中多源异构协议的高精度解析需求。【方法】为解决上述问题,本文提出mBERT协同多源领域自适应与结构化掩码策略的语义推断方法。通过mBERT模型实现跨协议通用语义表示;利用结合注意力权重与位置编码设计的结构化掩码策略,增强模型对协议结构和语义内在联系的表示能力,提高语义推断方法的自动化程度和效率;利用结合对抗训练的多源领域自适应逐步微调策略,提升模型对多个源协议的语义通用表示能力,增强其在多种工控协议上的适用性,实现关键字语义的有效推断。【结果】在辽宁省石油化工行业信息安全重点实验室的典型能源企业攻防演练靶场中开展实验验证,采集了S7comm、Modbus/TCP和EtherNet/IP三种工控协议数据,并利用协议复杂度评分机制组建训练数据集。结果表明,多源领域自适应逐步微调策略能够显著提升模型性能,将其与结构化掩码策略结合,进一步提高了语义推断精度,且本文方法在精确度、召回率与F_(1)分数指标上均显著优于现有基线方法。【结论】本文提出了mBERT协同多源领域自适应与结构化掩码策略的语义推断方法,在语义推断中采用高维球面映射与多任务损失函数,增强了不同语义类别的区分度与模型对协议语义的深层辨识能力。本文方法不仅显著降低了对人工先验知识的依赖,也提升了语义推断效率与跨协议适用性,为工控协议逆向分析及工业系统安全防护提供了具备理论支撑的新路径。
基金supported in part by the Australian Research Council Discovery Early Career Researcher Award(DE200101128)Australian Research Council(DP190101557)。
文摘In this paper,an adaptive dynamic programming(ADP)strategy is investigated for discrete-time nonlinear systems with unknown nonlinear dynamics subject to input saturation.To save the communication resources between the controller and the actuators,stochastic communication protocols(SCPs)are adopted to schedule the control signal,and therefore the closed-loop system is essentially a protocol-induced switching system.A neural network(NN)-based identifier with a robust term is exploited for approximating the unknown nonlinear system,and a set of switch-based updating rules with an additional tunable parameter of NN weights are developed with the help of the gradient descent.By virtue of a novel Lyapunov function,a sufficient condition is proposed to achieve the stability of both system identification errors and the update dynamics of NN weights.Then,a value iterative ADP algorithm in an offline way is proposed to solve the optimal control of protocol-induced switching systems with saturation constraints,and the convergence is profoundly discussed in light of mathematical induction.Furthermore,an actor-critic NN scheme is developed to approximate the control law and the proposed performance index function in the framework of ADP,and the stability of the closed-loop system is analyzed in view of the Lyapunov theory.Finally,the numerical simulation results are presented to demonstrate the effectiveness of the proposed control scheme.
文摘Considering that weak channel collision detection ability, long propagation delay and heavy load in LEO satellite communications, a valid adaptive APRMA MAC protocol was proposed. Different access probability functions for different services were obtained and appropriate access probabilities for voice and data users were updated slot by slot based on the estimation of the voice traffic and the channel status. In the proposed MAC protocol limited wireless resource is allocated reasonably by multiple users and high capacity was achieved. Three performance parameters: voice packet loss probability, average delay of data packets and throughput of data packets were considered in simulation. Finally simulation results demonstrated that the performance of system was improved by the APRMA compared with the conventional PRMA, with an acceptable trade-off between QoS of voice and delay of data.
文摘Background: The importance of adapting evidence-based health interventions to enhance their congruence with the beliefs of ethno-cultural communities is well recognized. Although a systematic cultural adaptation process is available, it lacks specific instructions on how to adapt interventions so that they are aligned with cultural beliefs. In this paper, we present an integrated strategy that operationalizes the adaptation process by describing specific practical instructions on how to align interventions with cultural beliefs. Methods: The strategy integrates concept and intervention mapping, and uses mixed methods for gathering data from community representatives. The data pertain to a community’s cultural beliefs and values related to a health problem, acceptability of evidence-based interventions targeting the problem, and aspects of the interventions that should be modified to enhance their fit with cultural beliefs. A step-by-step protocol is described to guide application of the integrated strategy for cultural adaptation. Conclusions: The strength of the integrated strategy relies on the use of concept and intervention mapping approaches for specifying a step-by-step protocol to actively engage community representatives in the cultural adaptation of interventions. Future research should evaluate the utility of this strategy.
文摘Compatibility is the precondition to ensure the correct interaction among components in composition process, how to make the mismatch components coordinate correctly is a vital problem in component composition. This paper first modeled component behavior by LTS and expressed action mapping as synchronous vector then defined the sequential relationship among synchronous vectors as adaptation contract. Thirdly we analyzed the different mismatch situations and corresponding adaptation strategies. At last designed adaptation algorithm to produce adaptor specification automatically and ensured the mismatch components can correct interaction under the mediation of adaptor and verified the validity of proposed method through an application system.
基金Supported by National Key Technology R&D Program of the Ministry of Science and Technology (2012BAB15B01)
文摘This paper presents adaptive hybrid protocols based on the declarative network and mainly discusses the principle and realization of the Bayesian-estimation based adaptive hybrid protocol in the declarative network, which is well adapted to the Mobile Ad hoc NETwork (MANET). The adaptive hybrid protocol is designed for ad hoc networks which have characteristics like self-organizing, no trusted party, flexibility, etc. The nodes that run the hybrid protocol can automatically select one routing protocol that is suitable for different network environment. The Bayesian-estimation based adaptive strategy, that improves the adaptability and stability of the protocol, succeeds in the Rapidnet, a declarative network engine. The result in the Rapidnet proves that the hybrid protocol and the adaptive strategy are feasible. The experiment on the ns-3 simulator, an emerging discrete-event network simulator, validates that this protocol performs well and reduces communication overheads.
