I type system model of CCCAM(Contention-Collision Cancellation Access Mode) is studied through mathematical modelling and simulation. There are two innovations: (1) in the process of mathematical modelling, the instan...I type system model of CCCAM(Contention-Collision Cancellation Access Mode) is studied through mathematical modelling and simulation. There are two innovations: (1) in the process of mathematical modelling, the instance of 'serving customers unsuccessfully' is taken into account; (2) the time at which customers depart after having been served successfully are chosen to be the embedded point, thereby 'free period' is introduced reasonably. So the mathematical modelling and analysis result in this paper are significant for application of wire star LAN and wireless star LAN.展开更多
Hanoi’s rapid urbanization has led to a surge in private vehicle ownership, particularly motorcycles, amidst inadequate public transportation infrastructure. Despite government efforts, many still prefer motorized tr...Hanoi’s rapid urbanization has led to a surge in private vehicle ownership, particularly motorcycles, amidst inadequate public transportation infrastructure. Despite government efforts, many still prefer motorized transport, citing mobility and safety concerns, exacerbated by insufficient pedestrian infrastructure. This study examines the motivations behind this reliance on motorized vehicles, particularly motorcycles, in Hanoi. Findings reveal safety and convenience as primary factors driving motorized transport use, especially for accessing bus stations. Economic incentives could promote non-motorized travel and public transport adoption. Policy implications highlight the importance of addressing economic factors and improving access infrastructure to manage motorized vehicle reliance and foster sustainable urban mobility in Hanoi.展开更多
针对混合天线模式的无人机(Unmanned Aerial Verial,UAV)自组网接入协议存在时钟内同步困难以及时隙利用率低的问题,提出一种基于扇区的混合天线模式时分多址接入协同优化协议(Sector-based Collaborative Optimized Protocol for Hybri...针对混合天线模式的无人机(Unmanned Aerial Verial,UAV)自组网接入协议存在时钟内同步困难以及时隙利用率低的问题,提出一种基于扇区的混合天线模式时分多址接入协同优化协议(Sector-based Collaborative Optimized Protocol for Hybrid Antenna Mode Time Division Multiple Access,SCOP-HTDMA)。该协议采用集中式网络架构,包含一个中心UAV节点和若干子节点,所有节点均配备相同的全向/定向双模智能天线。通过引入地磁场辅助扇区确认机制,有效支持混合天线模式下的时钟内同步,优化现有的时帧结构并设计全向-定向协同多播机制以提升时隙利用率。仿真结果表明,在不同业务负载和节点规模下,该协议在平均时延与丢包率方面均优于基于位置预测的定向媒体接入控制协议(Position-Prediction-based Directional Media Access Control Protocol,PPMAC)和固定帧长的集中式UAV媒体接入控制协议(Centralized UAV Media Access Control Protocol,CU-MAC)。展开更多
The aim of this work is to explore the impact of regional transit service on tour-based commuter travel behavior by using the Bayesian hierarchical multinomial logit model, accounting for the spatial heterogeneity of ...The aim of this work is to explore the impact of regional transit service on tour-based commuter travel behavior by using the Bayesian hierarchical multinomial logit model, accounting for the spatial heterogeneity of the people living in the same area.With two indicators, accessibility and connectivity measured at the zone level, the regional transit service is captured and then related to the travel mode choice behavior. The sample data are selected from Washington-Baltimore Household Travel Survey in 2007,including all the trips from home to workplace in morning hours in Baltimore city. Traditional multinomial logit model using Bayesian approach is also estimated. A comparison of the two different models shows that ignoring the spatial context can lead to a misspecification of the effects of the regional transit service on travel behavior. The results reveal that improving transit service at regional level can be effective in reducing auto use for commuters after controlling for socio-demographics and travel-related factors.This work provides insights for interpreting tour-based commuter travel behavior by using recently developed methodological approaches. The results of this work will be helpful for engineers, urban planners, and transit operators to decide the needs to improve regional transit service and spatial location efficiently.展开更多
Functional failure mode of commercial deep sub-micron static random access memory（SRAM） induced by total dose irradiation is experimentally analyzed and verified by circuit simulation. We extensively characterize th...Functional failure mode of commercial deep sub-micron static random access memory（SRAM） induced by total dose irradiation is experimentally analyzed and verified by circuit simulation. We extensively characterize the functional failure mode of the device by testing its electrical parameters and function with test patterns covering different functional failure modes. Experimental results reveal that the functional failure mode of the device is a temporary function interruption caused by peripheral circuits being sensitive to the standby current rising. By including radiation-induced threshold shift and off-state leakage current in memory cell transistors, we simulate the influence of radiation on the functionality of the memory cell. Simulation results reveal that the memory cell is tolerant to irradiation due to its high stability, which agrees with our experimental result.展开更多
基金Supported by Natural Science Foundation of Qingdao University
文摘I type system model of CCCAM(Contention-Collision Cancellation Access Mode) is studied through mathematical modelling and simulation. There are two innovations: (1) in the process of mathematical modelling, the instance of 'serving customers unsuccessfully' is taken into account; (2) the time at which customers depart after having been served successfully are chosen to be the embedded point, thereby 'free period' is introduced reasonably. So the mathematical modelling and analysis result in this paper are significant for application of wire star LAN and wireless star LAN.
文摘Hanoi’s rapid urbanization has led to a surge in private vehicle ownership, particularly motorcycles, amidst inadequate public transportation infrastructure. Despite government efforts, many still prefer motorized transport, citing mobility and safety concerns, exacerbated by insufficient pedestrian infrastructure. This study examines the motivations behind this reliance on motorized vehicles, particularly motorcycles, in Hanoi. Findings reveal safety and convenience as primary factors driving motorized transport use, especially for accessing bus stations. Economic incentives could promote non-motorized travel and public transport adoption. Policy implications highlight the importance of addressing economic factors and improving access infrastructure to manage motorized vehicle reliance and foster sustainable urban mobility in Hanoi.
文摘针对混合天线模式的无人机(Unmanned Aerial Verial,UAV)自组网接入协议存在时钟内同步困难以及时隙利用率低的问题,提出一种基于扇区的混合天线模式时分多址接入协同优化协议(Sector-based Collaborative Optimized Protocol for Hybrid Antenna Mode Time Division Multiple Access,SCOP-HTDMA)。该协议采用集中式网络架构,包含一个中心UAV节点和若干子节点,所有节点均配备相同的全向/定向双模智能天线。通过引入地磁场辅助扇区确认机制,有效支持混合天线模式下的时钟内同步,优化现有的时帧结构并设计全向-定向协同多播机制以提升时隙利用率。仿真结果表明,在不同业务负载和节点规模下,该协议在平均时延与丢包率方面均优于基于位置预测的定向媒体接入控制协议(Position-Prediction-based Directional Media Access Control Protocol,PPMAC)和固定帧长的集中式UAV媒体接入控制协议(Centralized UAV Media Access Control Protocol,CU-MAC)。
基金Project(71173061)supported by the National Natural Science Foundation of ChinaProject(2013U-6)supported by Key Laboratory of Eco Planning & Green Building,Ministry of Education(Tsinghua University),China
文摘The aim of this work is to explore the impact of regional transit service on tour-based commuter travel behavior by using the Bayesian hierarchical multinomial logit model, accounting for the spatial heterogeneity of the people living in the same area.With two indicators, accessibility and connectivity measured at the zone level, the regional transit service is captured and then related to the travel mode choice behavior. The sample data are selected from Washington-Baltimore Household Travel Survey in 2007,including all the trips from home to workplace in morning hours in Baltimore city. Traditional multinomial logit model using Bayesian approach is also estimated. A comparison of the two different models shows that ignoring the spatial context can lead to a misspecification of the effects of the regional transit service on travel behavior. The results reveal that improving transit service at regional level can be effective in reducing auto use for commuters after controlling for socio-demographics and travel-related factors.This work provides insights for interpreting tour-based commuter travel behavior by using recently developed methodological approaches. The results of this work will be helpful for engineers, urban planners, and transit operators to decide the needs to improve regional transit service and spatial location efficiently.
文摘Functional failure mode of commercial deep sub-micron static random access memory（SRAM） induced by total dose irradiation is experimentally analyzed and verified by circuit simulation. We extensively characterize the functional failure mode of the device by testing its electrical parameters and function with test patterns covering different functional failure modes. Experimental results reveal that the functional failure mode of the device is a temporary function interruption caused by peripheral circuits being sensitive to the standby current rising. By including radiation-induced threshold shift and off-state leakage current in memory cell transistors, we simulate the influence of radiation on the functionality of the memory cell. Simulation results reveal that the memory cell is tolerant to irradiation due to its high stability, which agrees with our experimental result.
