A 1.8-V 64-kb four-way set-associative CMOS cache memory implemented by 0.18μm/1.8V 1P6M logic CMOS technology for a super performance 32-b RISC microprocessor is presented.For comparison,a conventional parallel acce...A 1.8-V 64-kb four-way set-associative CMOS cache memory implemented by 0.18μm/1.8V 1P6M logic CMOS technology for a super performance 32-b RISC microprocessor is presented.For comparison,a conventional parallel access cache with the same storage and organization is also designed and simulated using the same technology.Simulation results indicate that by using sequential access,power reduction of 26% on a cache hit and 35% on a cache miss is achieved.High-speed approaches including modified current-mode sense amplifier and split dynamic tag comparators are adopted to achieve fast data access.Simulation results indicate that a typical clock to data access of 2.7ns is achieved...展开更多
Objective Right ventricular outflow tract septum has become widely used us an electrode placement site. However, data concerning lead performances and complications for lead repositioning with this technique were scan...Objective Right ventricular outflow tract septum has become widely used us an electrode placement site. However, data concerning lead performances and complications for lead repositioning with this technique were scant. The purpose of this study was to observe long- term lead performances and complications of right ventricular outflow tract septal pacing and provide evidences for choosing an optimal electrode implantation site. Methods Thirty-six patients with septal active electrode implantation and 39 with apical passive electrode implantation were enrolled in this study. Pacing threshold, R-wave sensing, lead impedance, pacing QRS width and pacing-related compli- cations for two groups at implantation and follow-up were compared. Results There were higher pacing threshold and shorter pacing QRS width at implantation in the septal group compared with the apical group. There were no differences between the septal and the apical groups in pacing threshold, R-wave sensitivity, lead impedance and pace-related complication during a follow-up. Conclusions Right ventricular outflow tract septum could be used as a first choice for implantation site because it had long-term stable lead performances and no serious complications compared with the traditional apical site.展开更多
For the discontinuous occupancy of primary users in cognitive radio networks(CRN),the time-varying of spectrum holes becomes more and more highlighted.In the dynamic environment,cognitive users can access channels tha...For the discontinuous occupancy of primary users in cognitive radio networks(CRN),the time-varying of spectrum holes becomes more and more highlighted.In the dynamic environment,cognitive users can access channels that are not occupied by primary users,but they have to hand off to other spectrum holes to continue communication when primary users come back,which brings new security problems.Tracking user attack(TUA) is a typical attack during spectrum handoff,which will invalidate handoff by preventing user accessing,and break down the whole network.In this paper,we propose a Channel Selection Information Hiding scheme(CSIH) to defense TUA.With the proposed scheme,we can destroy the routes to the root node of the attack tree by hiding the information of channel selection and enhance the security of cognitive radio networks.展开更多
As a major criterion for textuality and a prominent term in discourse analysis, discourse cohesion is used on the one hand, to identify the linguistic features that cause the sentences to ＂cohere＂, and on the other ...As a major criterion for textuality and a prominent term in discourse analysis, discourse cohesion is used on the one hand, to identify the linguistic features that cause the sentences to ＂cohere＂, and on the other hand, is to make the sentences in the discourse display some kind of mutual dependence. The paper has intensively analyzed the radio interview between Edward Heath and an interviewer from the perspective of discourse cohesion. After an in-depth analysis, the paper concludes that the interview is quite structurally cohesive by adopting several grammatical cohesive devices or ties, such as the verbal form, the time relator, the conjunction, the reference, the substitution, and the ellipsis, especially the reference and conjunction展开更多
Dynamic spectrum access policy is crucial in improving the performance of over- lay cognitive radio networks. Most of the previ- ous works on spectrum sensing and dynamic spe- ctrum access consider the sensing effecti...Dynamic spectrum access policy is crucial in improving the performance of over- lay cognitive radio networks. Most of the previ- ous works on spectrum sensing and dynamic spe- ctrum access consider the sensing effective- ness and spectrum utilization as the design cri- teria, while ignoring the energy related issues and QoS constraints. In this article, we propose a QoS provisioning energy saving dynamic acc- ess policy using stochastic control theory con- sidering the time-varying characteristics of wir- eless channels because of fading and mobility. The proposed scheme determines the sensing action and selects the optimal spectrum using the corresponding power setting in each decis- ion epoch according to the channel state with the objective being to minimise both the flame error rate and energy consumption. We use the Hidden Markov Model （HMM） to model a wir- eless channel, since the channel state is not dir- ectly observable at the receiver, but is instead embedded in the received signal. The proced- ure of dynamic spectrum access is formulated as a Markov decision process which can be sol- ved using linear programming and the primal- dual index heuristic algorithm, and the obta- ined policy has an index-ability property that can be easily implemented in real systems. Sim- ulation results are presented to show the per- formance improvement caused by the propo- sed approach.展开更多
The length of data frame is an important parameter in Medium Access Control(MAC) layer protocol. A method of finding the optimal length of data frame when impulsive disturbance is involved in PowerLine Communications ...The length of data frame is an important parameter in Medium Access Control(MAC) layer protocol. A method of finding the optimal length of data frame when impulsive disturbance is involved in PowerLine Communications (PLC) is proposed. Having analyzed the characteristics of impulsive disturbance in powerline and the collision mechanism between the disturbance and data frame, this letter gives the function of the network channel utilization with the length of data frame in MAC layer and the impulsive disturbance. Our stochastic process simulation shows that it is feasible to get the optimal length of data frame.展开更多
In distributed systems independent agents need to interact with each other to accomplish their task. Modern peer-to-peer computing technologies always concern with enabling interaction among agents and help them coope...In distributed systems independent agents need to interact with each other to accomplish their task. Modern peer-to-peer computing technologies always concern with enabling interaction among agents and help them cooperate with each other. But in fact, access control should also be considered to limit interaction to make it harmless. This paper proposed a proxy based rule regulated interaction (PBRRI) model. Role based access control is introduced for security concerns. Regulation rules are enforced in a distributed manner so that PBRRI can be applied to the open distributed systems such as Internet.展开更多
Cognitive radio(CR) is regarded as a promising technology for providing a high spectral efficiency to mobile users by using heterogeneous wireless network architectures and dynamic spectrum access techniques.However,c...Cognitive radio(CR) is regarded as a promising technology for providing a high spectral efficiency to mobile users by using heterogeneous wireless network architectures and dynamic spectrum access techniques.However,cognitive radio networks(CRNs)may also impose some challenges due to the ever increasing complexity of network architecture,the increasing complexity with configuration and management of large-scale networks,fluctuating nature of the available spectrum,diverse Quality-of-Service(QoS)requirements of various applications,and the intensifying difficulties of centralized control,etc.Spectrum management functions with self-organization features can be used to address these challenges and realize this new network paradigm.In this paper,fundamentals of CR,including spectrum sensing,spectrum management,spectrum mobility and spectrum sharing,have been surveyed,with their paradigms of self-organization being emphasized.Variant aspects of selforganization paradigms in CRNs,including critical functionalities of Media Access Control(MAC)- and network-layer operations,are surveyed and compared.Furthermore,new directions and open problems in CRNs are also identified in this survey.展开更多
Advanced Metering Infrastructure （AMI） enables smart grids to involve power consumers in the business process of power generation transmission, distribution and consumption. However, the participant of consumers cha...Advanced Metering Infrastructure （AMI） enables smart grids to involve power consumers in the business process of power generation transmission, distribution and consumption. However, the participant of consumers challenges the current power systems with system integration and cooperation and security issues. In this paper, the authors introduce a service-oriented approach to AMI aiming at solving the intercommunication problem and meanwhile providing a trust and secure environment for smart grids. In this approach heterogeneous systems expose services to the network. System integration and cooperation are done through service composition. A generic service interfacing method is designed to develop standardized services for heterogeneous power systems. Moreover, role-based access control mechanism is used to guarantee the secure access to smart grids. With the seamless communication between consumers and power systems and among power systems themselves, this service-oriented AMI can associate consumers with actual system workload and furthermore support the intelligent running of power systems.展开更多
Objective To explore whether acupuncture intervention can reduce the concurrent omalgia of ischemic stroke patients and initially explore the feasibility of follow-up research on long-term acupuncture. Methods Three h...Objective To explore whether acupuncture intervention can reduce the concurrent omalgia of ischemic stroke patients and initially explore the feasibility of follow-up research on long-term acupuncture. Methods Three hundred pa ents who conformed to the research criteria and voluntarily took part in the research were randomized into an acupuncture group and a regular therapy group with envelope method. The 150 cases in the acupuncture group received the combined treatment of electroacupuncture（EA） and moxibus on based on regular treatments for a total of 4 weeks. The 150 cases in the regular therapy group received regular treatments. The omalgia incidence number were observed at 1,2,3,6,12 months follow-up,simplified Fugl-Meyer of the upper-extremity was evaluated 4 weeks after treatment,modified Rankin Scale was conducted to assess the number of rela vely independent patients and the patients acceptance for acupuncture therapy at 6 months follow-up. Results After 4 weeks of treatments,although the comparative devia ons of the omalgia incidence number and the simplified Fugl-Meyer in the two groups had no sta s cal significance（P0.05）,the omalgia incidence numbers in the acupuncture group at 2nd,3rd,6th and 12th month followups were different significantly compared with those in the regular therapy group（P0.05）; meanwhile,at 6 months follow-up,the rela vely independent number of the pa ents assessed by modified Rankin Scale in the acupuncture group was superior to that in the regular therapy group（P0.05）. The number of pa ents who adhered to the acupuncture rehab therapy in the acupuncture group was greater than that in the regular therapy group（P0.05）. Conclusion Acupuncture intervention during the acute stage of ischemic stroke can not only effectively reduce the incidence of omalgia complication,but also play an assisting role in improving the patients＇ ability of independent living; meanwhile,the systema c visits and treatments of acupuncture may feature assis ng significance in the construc on of the special disease and special skills of the acupuncturology.展开更多
Most existing media access control(MAC) protocols in power line communication(PLC) networks just discard the colliding data packets when collision occurs.The collision deteriorates throughput and delay performance of ...Most existing media access control(MAC) protocols in power line communication(PLC) networks just discard the colliding data packets when collision occurs.The collision deteriorates throughput and delay performance of system under high traffic conditions.This article presents a novel media access scheme with fast collision resolution for in-home power line networks.It works by first recognizing the colliding stations through detecting the inserted unique ID sequence ahead of data packets,then the source nodes retransmitting their packets immediately after the collision slot.The proposed protocol maintains the benefits of ALOHA systems.It needs no scheduling overhead and is suitable for bursty sources,such as multimedia data packets.Computer simulations have demonstrated that this approach can achieve high throughput due to its ability of resolving collisions.展开更多
文摘A 1.8-V 64-kb four-way set-associative CMOS cache memory implemented by 0.18μm/1.8V 1P6M logic CMOS technology for a super performance 32-b RISC microprocessor is presented.For comparison,a conventional parallel access cache with the same storage and organization is also designed and simulated using the same technology.Simulation results indicate that by using sequential access,power reduction of 26% on a cache hit and 35% on a cache miss is achieved.High-speed approaches including modified current-mode sense amplifier and split dynamic tag comparators are adopted to achieve fast data access.Simulation results indicate that a typical clock to data access of 2.7ns is achieved...
文摘Objective Right ventricular outflow tract septum has become widely used us an electrode placement site. However, data concerning lead performances and complications for lead repositioning with this technique were scant. The purpose of this study was to observe long- term lead performances and complications of right ventricular outflow tract septal pacing and provide evidences for choosing an optimal electrode implantation site. Methods Thirty-six patients with septal active electrode implantation and 39 with apical passive electrode implantation were enrolled in this study. Pacing threshold, R-wave sensing, lead impedance, pacing QRS width and pacing-related compli- cations for two groups at implantation and follow-up were compared. Results There were higher pacing threshold and shorter pacing QRS width at implantation in the septal group compared with the apical group. There were no differences between the septal and the apical groups in pacing threshold, R-wave sensitivity, lead impedance and pace-related complication during a follow-up. Conclusions Right ventricular outflow tract septum could be used as a first choice for implantation site because it had long-term stable lead performances and no serious complications compared with the traditional apical site.
基金the National Natural Science Foundation of China under Grant No.61172068,6137317 0.The Fundamental Research Funds for the Central Universities，Program for New Century Excellent Talents in University
文摘For the discontinuous occupancy of primary users in cognitive radio networks(CRN),the time-varying of spectrum holes becomes more and more highlighted.In the dynamic environment,cognitive users can access channels that are not occupied by primary users,but they have to hand off to other spectrum holes to continue communication when primary users come back,which brings new security problems.Tracking user attack(TUA) is a typical attack during spectrum handoff,which will invalidate handoff by preventing user accessing,and break down the whole network.In this paper,we propose a Channel Selection Information Hiding scheme(CSIH) to defense TUA.With the proposed scheme,we can destroy the routes to the root node of the attack tree by hiding the information of channel selection and enhance the security of cognitive radio networks.
文摘As a major criterion for textuality and a prominent term in discourse analysis, discourse cohesion is used on the one hand, to identify the linguistic features that cause the sentences to ＂cohere＂, and on the other hand, is to make the sentences in the discourse display some kind of mutual dependence. The paper has intensively analyzed the radio interview between Edward Heath and an interviewer from the perspective of discourse cohesion. After an in-depth analysis, the paper concludes that the interview is quite structurally cohesive by adopting several grammatical cohesive devices or ties, such as the verbal form, the time relator, the conjunction, the reference, the substitution, and the ellipsis, especially the reference and conjunction
基金supported by the National Natural Science Foundation of China under Grant No.61101107the Beijing Higher Education Young Elite Teacher Project under Grant No.YETP0439
文摘Dynamic spectrum access policy is crucial in improving the performance of over- lay cognitive radio networks. Most of the previ- ous works on spectrum sensing and dynamic spe- ctrum access consider the sensing effective- ness and spectrum utilization as the design cri- teria, while ignoring the energy related issues and QoS constraints. In this article, we propose a QoS provisioning energy saving dynamic acc- ess policy using stochastic control theory con- sidering the time-varying characteristics of wir- eless channels because of fading and mobility. The proposed scheme determines the sensing action and selects the optimal spectrum using the corresponding power setting in each decis- ion epoch according to the channel state with the objective being to minimise both the flame error rate and energy consumption. We use the Hidden Markov Model （HMM） to model a wir- eless channel, since the channel state is not dir- ectly observable at the receiver, but is instead embedded in the received signal. The proced- ure of dynamic spectrum access is formulated as a Markov decision process which can be sol- ved using linear programming and the primal- dual index heuristic algorithm, and the obta- ined policy has an index-ability property that can be easily implemented in real systems. Sim- ulation results are presented to show the per- formance improvement caused by the propo- sed approach.
文摘The length of data frame is an important parameter in Medium Access Control(MAC) layer protocol. A method of finding the optimal length of data frame when impulsive disturbance is involved in PowerLine Communications (PLC) is proposed. Having analyzed the characteristics of impulsive disturbance in powerline and the collision mechanism between the disturbance and data frame, this letter gives the function of the network channel utilization with the length of data frame in MAC layer and the impulsive disturbance. Our stochastic process simulation shows that it is feasible to get the optimal length of data frame.
文摘In distributed systems independent agents need to interact with each other to accomplish their task. Modern peer-to-peer computing technologies always concern with enabling interaction among agents and help them cooperate with each other. But in fact, access control should also be considered to limit interaction to make it harmless. This paper proposed a proxy based rule regulated interaction (PBRRI) model. Role based access control is introduced for security concerns. Regulation rules are enforced in a distributed manner so that PBRRI can be applied to the open distributed systems such as Internet.
基金ACKNOWLEDGEMENT This work was supported by National Natural Science Foundation of China （No. 61172050）, Program for New Century Excellent Talents in University （NECT-12-0774）, the open research fund of National Mobile Communications Research Laboratory, Southeast University （No.2013D12）, the Foundation of Beijing Engineering and Technology Research Center for Convergence Networks and Ubiquitous Services. The corresponding author is Dr. Zhongshan Zhang.
文摘Cognitive radio(CR) is regarded as a promising technology for providing a high spectral efficiency to mobile users by using heterogeneous wireless network architectures and dynamic spectrum access techniques.However,cognitive radio networks(CRNs)may also impose some challenges due to the ever increasing complexity of network architecture,the increasing complexity with configuration and management of large-scale networks,fluctuating nature of the available spectrum,diverse Quality-of-Service(QoS)requirements of various applications,and the intensifying difficulties of centralized control,etc.Spectrum management functions with self-organization features can be used to address these challenges and realize this new network paradigm.In this paper,fundamentals of CR,including spectrum sensing,spectrum management,spectrum mobility and spectrum sharing,have been surveyed,with their paradigms of self-organization being emphasized.Variant aspects of selforganization paradigms in CRNs,including critical functionalities of Media Access Control(MAC)- and network-layer operations,are surveyed and compared.Furthermore,new directions and open problems in CRNs are also identified in this survey.
文摘Advanced Metering Infrastructure （AMI） enables smart grids to involve power consumers in the business process of power generation transmission, distribution and consumption. However, the participant of consumers challenges the current power systems with system integration and cooperation and security issues. In this paper, the authors introduce a service-oriented approach to AMI aiming at solving the intercommunication problem and meanwhile providing a trust and secure environment for smart grids. In this approach heterogeneous systems expose services to the network. System integration and cooperation are done through service composition. A generic service interfacing method is designed to develop standardized services for heterogeneous power systems. Moreover, role-based access control mechanism is used to guarantee the secure access to smart grids. With the seamless communication between consumers and power systems and among power systems themselves, this service-oriented AMI can associate consumers with actual system workload and furthermore support the intelligent running of power systems.
基金Supported by Sichuan Provincial Bureau of Science&Technology(2010 support plan)
文摘Objective To explore whether acupuncture intervention can reduce the concurrent omalgia of ischemic stroke patients and initially explore the feasibility of follow-up research on long-term acupuncture. Methods Three hundred pa ents who conformed to the research criteria and voluntarily took part in the research were randomized into an acupuncture group and a regular therapy group with envelope method. The 150 cases in the acupuncture group received the combined treatment of electroacupuncture（EA） and moxibus on based on regular treatments for a total of 4 weeks. The 150 cases in the regular therapy group received regular treatments. The omalgia incidence number were observed at 1,2,3,6,12 months follow-up,simplified Fugl-Meyer of the upper-extremity was evaluated 4 weeks after treatment,modified Rankin Scale was conducted to assess the number of rela vely independent patients and the patients acceptance for acupuncture therapy at 6 months follow-up. Results After 4 weeks of treatments,although the comparative devia ons of the omalgia incidence number and the simplified Fugl-Meyer in the two groups had no sta s cal significance（P0.05）,the omalgia incidence numbers in the acupuncture group at 2nd,3rd,6th and 12th month followups were different significantly compared with those in the regular therapy group（P0.05）; meanwhile,at 6 months follow-up,the rela vely independent number of the pa ents assessed by modified Rankin Scale in the acupuncture group was superior to that in the regular therapy group（P0.05）. The number of pa ents who adhered to the acupuncture rehab therapy in the acupuncture group was greater than that in the regular therapy group（P0.05）. Conclusion Acupuncture intervention during the acute stage of ischemic stroke can not only effectively reduce the incidence of omalgia complication,but also play an assisting role in improving the patients＇ ability of independent living; meanwhile,the systema c visits and treatments of acupuncture may feature assis ng significance in the construc on of the special disease and special skills of the acupuncturology.
文摘Most existing media access control(MAC) protocols in power line communication(PLC) networks just discard the colliding data packets when collision occurs.The collision deteriorates throughput and delay performance of system under high traffic conditions.This article presents a novel media access scheme with fast collision resolution for in-home power line networks.It works by first recognizing the colliding stations through detecting the inserted unique ID sequence ahead of data packets,then the source nodes retransmitting their packets immediately after the collision slot.The proposed protocol maintains the benefits of ALOHA systems.It needs no scheduling overhead and is suitable for bursty sources,such as multimedia data packets.Computer simulations have demonstrated that this approach can achieve high throughput due to its ability of resolving collisions.
