Traffic accidents involving pedestrians and drivers pose significant public health and safety concerns.Understanding the differential influences of road physical design attributes on crash frequencies for these two gr...Traffic accidents involving pedestrians and drivers pose significant public health and safety concerns.Understanding the differential influences of road physical design attributes on crash frequencies for these two groups is critical for developing targeted safety interventions.Considering that the zero-truncated characteristic of the data is uncertain,the results of the zero-truncated negative binomial models and traditional negative binomial models are calculated to seek the better model.The result revealed that the road surface conditions and vertical and horizontal curvature have greater influence on both pedestrian and driver compared to number of lanes and speed limit.And speed limits were more pronounced for pedestrian crash frequency than driver group.Conversely,the effect of different types of intersections was stronger for driver crash frequency.The differential influences of road physical design attributes on traffic crash frequencies for pedestrians versus drivers highlight the importance of adopting a user-centric approach to transportation safety planning and infrastructure design.Tailoring interventions to address the unique needs and vulnerabilities of different road user groups can lead to more effective safety improvements and better overall traffic safety outcomes.展开更多
The effects of different habits of the drivers on gear shifting strategies for manual powertrain were investigated. For the realization of simulation, the shifting habits of the drivers were conducted in the Advisor s...The effects of different habits of the drivers on gear shifting strategies for manual powertrain were investigated. For the realization of simulation, the shifting habits of the drivers were conducted in the Advisor software to investigate and compare the emission rates. Simulation was developed based on the optimal gear shifting strategy and criteria and was validated both in fuel economy and emissions by analyzing the results in the various driving cycle and driving styles. To explore an optimal gear shifting strategy with best fuel economy and lowest emission for a manual transmission, a strategy was designed with a highest possible gear criterion as long as the torque requirement can be satisfied. Based on two different criteria, namely the engine working conditions and the driver's intention, the governing parameters in decision making for gear shifting of manual transmission in conventional engine were discussed. It is also shown that the optimum gear shifting strategy is based on that both the engine state and the driver's intention eliminates unnecessary shiftings that are present when the intention is overlooked. The optimum shifting habit and the best driving cycle in terms of minimum emissions and fuel consumption were proposed.展开更多
为满足监控领域摄像头驱动替换便捷性和快速开发的需求,基于AR9311芯心在Linux系统上设计了一种网络摄像头。该系统采用媒体处理软件平台(MPP)进行设计,摄像头驱动以应用层驱动库的方式进行调用,应用软件通过MPP提供的接口快速完成相关...为满足监控领域摄像头驱动替换便捷性和快速开发的需求,基于AR9311芯心在Linux系统上设计了一种网络摄像头。该系统采用媒体处理软件平台(MPP)进行设计,摄像头驱动以应用层驱动库的方式进行调用,应用软件通过MPP提供的接口快速完成相关功能开发。文中以GC_2053摄像头为例,介绍了其在MPP架构下应用层驱动的设计,重点分析了如何通过VI视频采集模块获取视频图像,通过VPSS视频处理子系统模块处理图像,通过VENC编码模块进行编码输出码流。通过RTSP协议进行网络传输,通过解码软件VLC media player进行播放。经过测试,视频传输稳定,图像显示清晰,能够满足监控领域的要求。展开更多
基金Projects(52102407,52472354)supported by the National Natural Science Foundation of China。
文摘Traffic accidents involving pedestrians and drivers pose significant public health and safety concerns.Understanding the differential influences of road physical design attributes on crash frequencies for these two groups is critical for developing targeted safety interventions.Considering that the zero-truncated characteristic of the data is uncertain,the results of the zero-truncated negative binomial models and traditional negative binomial models are calculated to seek the better model.The result revealed that the road surface conditions and vertical and horizontal curvature have greater influence on both pedestrian and driver compared to number of lanes and speed limit.And speed limits were more pronounced for pedestrian crash frequency than driver group.Conversely,the effect of different types of intersections was stronger for driver crash frequency.The differential influences of road physical design attributes on traffic crash frequencies for pedestrians versus drivers highlight the importance of adopting a user-centric approach to transportation safety planning and infrastructure design.Tailoring interventions to address the unique needs and vulnerabilities of different road user groups can lead to more effective safety improvements and better overall traffic safety outcomes.
文摘The effects of different habits of the drivers on gear shifting strategies for manual powertrain were investigated. For the realization of simulation, the shifting habits of the drivers were conducted in the Advisor software to investigate and compare the emission rates. Simulation was developed based on the optimal gear shifting strategy and criteria and was validated both in fuel economy and emissions by analyzing the results in the various driving cycle and driving styles. To explore an optimal gear shifting strategy with best fuel economy and lowest emission for a manual transmission, a strategy was designed with a highest possible gear criterion as long as the torque requirement can be satisfied. Based on two different criteria, namely the engine working conditions and the driver's intention, the governing parameters in decision making for gear shifting of manual transmission in conventional engine were discussed. It is also shown that the optimum gear shifting strategy is based on that both the engine state and the driver's intention eliminates unnecessary shiftings that are present when the intention is overlooked. The optimum shifting habit and the best driving cycle in terms of minimum emissions and fuel consumption were proposed.
文摘为满足监控领域摄像头驱动替换便捷性和快速开发的需求,基于AR9311芯心在Linux系统上设计了一种网络摄像头。该系统采用媒体处理软件平台(MPP)进行设计,摄像头驱动以应用层驱动库的方式进行调用,应用软件通过MPP提供的接口快速完成相关功能开发。文中以GC_2053摄像头为例,介绍了其在MPP架构下应用层驱动的设计,重点分析了如何通过VI视频采集模块获取视频图像,通过VPSS视频处理子系统模块处理图像,通过VENC编码模块进行编码输出码流。通过RTSP协议进行网络传输,通过解码软件VLC media player进行播放。经过测试,视频传输稳定,图像显示清晰,能够满足监控领域的要求。
