A novel structure is proposed for doubling the vertical breakdown voltage of silicon-on-insulator（SOI） devices. In this new structure, the conventional buried oxide（BOX） in an SOI device is split into two sections...A novel structure is proposed for doubling the vertical breakdown voltage of silicon-on-insulator（SOI） devices. In this new structure, the conventional buried oxide（BOX） in an SOI device is split into two sections： the source-section BOX and the drain-section BOX. A highly-doped Si layer, referred to as a non-depletion potential-clamped layer（NPCL）, is positioned under and close to the two BOX sections. In the split BOXes and the Si region above the BOXes, the blocking voltage（BV） is divided into two parts by the NPCL. The voltage in the NPCL is clamped to be nearly half of the drain voltage. When the drain voltage approaches a breakdown value, the voltage sustained by the source-section BOX and the Si region under the source are nearly the same as the voltage sustained by the drain-section BOX and the Si region under the drain. The vertical BV is therefore almost doubled. The effectiveness of this new structure was verified for a P-channel SOI lateral double-diffused metal-oxide semiconductor（LDMOS） and can be applied to other high-voltage SOI devices. The simulation results show that the BV in an NPCL P-channel SOI LDMOS is improved by 55% and the specific on-resistance（Ron,sp） is reduced by 69% in comparison to the conventional structure.展开更多
Field observations illustrated that, right-turn vehicles stopped at various positions when proceeding within the right-turn lanes, while some of them trespassed on the crosswalks with multiple stops. In this case, ped...Field observations illustrated that, right-turn vehicles stopped at various positions when proceeding within the right-turn lanes, while some of them trespassed on the crosswalks with multiple stops. In this case, pedestrians and bikes (ped/bike) are encountered unsmooth and hazardous crossings when right-turn vehicles encroaching their lanes. Meanwhile, this also causes conflicts between right-turn and through vehicles at the crossing street. To better protect ped/bike at crossings with right-turn vehicles, this paper proposes a concept of “right-turn vehicle box” (RTVB) as a supplemental treatment within right-turn lanes. Sight distance, geometric conditions, and behaviors of vehicles and ped/bike are key factors to consider so as to set up the criteria and to design the suitable treatment. A case study was conducted at an intersection pair in Houston, USA to shape the idea of RTVB, together with driving simulator tests under relevant scenarios. The preliminary crosscheck examination shows that the right-turn vehicle box could possibly provide ped/ bike with smoother and safer crossings. In the interim, the safety and efficiency of right-turn operations were also improved. To further validate the effects, implementation studies should be conducted before the RTVB can make its debut in practice. Future works will focus on the complete warrants and design details of this treatment. Moreover, the concept of “vehicle box” could also be transplanted to other places where turning movement(s) needs assistance or improvements.展开更多
为解决SONiC(software for open networking in the cloud)交换机操作系统对多模态网络(polymor phic network,PINet)中模态适配及模态管控问题,提出了一个基于P4Runtime的SONiC网元控制通道容器p4runtime-pins,使多模态网元设备可以支...为解决SONiC(software for open networking in the cloud)交换机操作系统对多模态网络(polymor phic network,PINet)中模态适配及模态管控问题,提出了一个基于P4Runtime的SONiC网元控制通道容器p4runtime-pins,使多模态网元设备可以支持多种网络模态流表的配置。p4runtime-pins容器通过gRPC服务模块实现与控制器的连接,使用邻近网元发现算法实现控制器对链路的发现。设计了网元端口更新算法解决了网元设备在实际应用环境中存在的端口变更问题。同时,针对SONiC网元交换机中硬件转发处理单元存在的流表支持性差异问题,设计了内部流表转存和gRPC网元代理功能,实现了不同网络模态流表的部署。实验结果表明,p4runtime-pins容器资源消耗低,仅占用了1.70%的CPU资源和0.45%的内存资源。同时,部署p4runtime-pins容器的SONiC网元设备能够准确地接收并配置控制器下发的流表规则,流表配置延迟仅为0.027~0.037 s。展开更多
针对传统农业灌渠流量测量装置成本高、测量精度低的问题,该研究设计了一种基于超声波时差法的方箱流量计。首先,设计了方箱流量计机械结构,提出错层阵列布局方法,有效增加通道数量。其次,设计了与之配套的多通道数据采集电路,通过增加...针对传统农业灌渠流量测量装置成本高、测量精度低的问题,该研究设计了一种基于超声波时差法的方箱流量计。首先,设计了方箱流量计机械结构,提出错层阵列布局方法,有效增加通道数量。其次,设计了与之配套的多通道数据采集电路,通过增加升压驱动电路和回波调理电路,对时间数字转换器(timer digital converter,TDC)测时电路进行改进,以提升测量距离和回波信号检测的准确性。利用模拟开关切换电路实现16通道共享测时电路,以降低电路成本。最后,数据处理中通过数据校正和引入53H改进算法、加权数据融合改进算法实现灌渠流速的精确测量。在静水试验中对数据采集电路的性能进行测试,同时,测试温度对测量结果的影响。在动水试验中,与电磁流量计测量结果进行了对比。结果表明,通道非线性误差最大为0.95%;通道不一致性为(0.047±0.032)ns,带来的水流速度误差最大为3.06×10^(-)4m/s;超声波换能器不一致性为(0.288±0.215)ns,带来的水流速度误差最大为2.50×10^(-3)m/s,以上误差可通过数据校正的方法予以修正。在20~40℃范围内,流速的均方差为1.70×10^(-4)m/s,温度对测量结果的影响可忽略不计。在动水试验中,方箱流量计测量相对于电磁流量计偏差为0.16%~0.93%,达到了与电磁流量计同等的测量精度。研究结果可为精确测量灌渠流量、实现高效节水灌溉提供技术支撑。展开更多
基金supported by the National Natural Science Foundation of China(Grant No.61404110)the National Higher-Education Institution General Research and Development Project,China(Grant No.2682014CX097)
文摘A novel structure is proposed for doubling the vertical breakdown voltage of silicon-on-insulator（SOI） devices. In this new structure, the conventional buried oxide（BOX） in an SOI device is split into two sections： the source-section BOX and the drain-section BOX. A highly-doped Si layer, referred to as a non-depletion potential-clamped layer（NPCL）, is positioned under and close to the two BOX sections. In the split BOXes and the Si region above the BOXes, the blocking voltage（BV） is divided into two parts by the NPCL. The voltage in the NPCL is clamped to be nearly half of the drain voltage. When the drain voltage approaches a breakdown value, the voltage sustained by the source-section BOX and the Si region under the source are nearly the same as the voltage sustained by the drain-section BOX and the Si region under the drain. The vertical BV is therefore almost doubled. The effectiveness of this new structure was verified for a P-channel SOI lateral double-diffused metal-oxide semiconductor（LDMOS） and can be applied to other high-voltage SOI devices. The simulation results show that the BV in an NPCL P-channel SOI LDMOS is improved by 55% and the specific on-resistance（Ron,sp） is reduced by 69% in comparison to the conventional structure.
文摘Field observations illustrated that, right-turn vehicles stopped at various positions when proceeding within the right-turn lanes, while some of them trespassed on the crosswalks with multiple stops. In this case, pedestrians and bikes (ped/bike) are encountered unsmooth and hazardous crossings when right-turn vehicles encroaching their lanes. Meanwhile, this also causes conflicts between right-turn and through vehicles at the crossing street. To better protect ped/bike at crossings with right-turn vehicles, this paper proposes a concept of “right-turn vehicle box” (RTVB) as a supplemental treatment within right-turn lanes. Sight distance, geometric conditions, and behaviors of vehicles and ped/bike are key factors to consider so as to set up the criteria and to design the suitable treatment. A case study was conducted at an intersection pair in Houston, USA to shape the idea of RTVB, together with driving simulator tests under relevant scenarios. The preliminary crosscheck examination shows that the right-turn vehicle box could possibly provide ped/ bike with smoother and safer crossings. In the interim, the safety and efficiency of right-turn operations were also improved. To further validate the effects, implementation studies should be conducted before the RTVB can make its debut in practice. Future works will focus on the complete warrants and design details of this treatment. Moreover, the concept of “vehicle box” could also be transplanted to other places where turning movement(s) needs assistance or improvements.
文摘为解决SONiC(software for open networking in the cloud)交换机操作系统对多模态网络(polymor phic network,PINet)中模态适配及模态管控问题,提出了一个基于P4Runtime的SONiC网元控制通道容器p4runtime-pins,使多模态网元设备可以支持多种网络模态流表的配置。p4runtime-pins容器通过gRPC服务模块实现与控制器的连接,使用邻近网元发现算法实现控制器对链路的发现。设计了网元端口更新算法解决了网元设备在实际应用环境中存在的端口变更问题。同时,针对SONiC网元交换机中硬件转发处理单元存在的流表支持性差异问题,设计了内部流表转存和gRPC网元代理功能,实现了不同网络模态流表的部署。实验结果表明,p4runtime-pins容器资源消耗低,仅占用了1.70%的CPU资源和0.45%的内存资源。同时,部署p4runtime-pins容器的SONiC网元设备能够准确地接收并配置控制器下发的流表规则,流表配置延迟仅为0.027~0.037 s。
文摘针对传统农业灌渠流量测量装置成本高、测量精度低的问题,该研究设计了一种基于超声波时差法的方箱流量计。首先,设计了方箱流量计机械结构,提出错层阵列布局方法,有效增加通道数量。其次,设计了与之配套的多通道数据采集电路,通过增加升压驱动电路和回波调理电路,对时间数字转换器(timer digital converter,TDC)测时电路进行改进,以提升测量距离和回波信号检测的准确性。利用模拟开关切换电路实现16通道共享测时电路,以降低电路成本。最后,数据处理中通过数据校正和引入53H改进算法、加权数据融合改进算法实现灌渠流速的精确测量。在静水试验中对数据采集电路的性能进行测试,同时,测试温度对测量结果的影响。在动水试验中,与电磁流量计测量结果进行了对比。结果表明,通道非线性误差最大为0.95%;通道不一致性为(0.047±0.032)ns,带来的水流速度误差最大为3.06×10^(-)4m/s;超声波换能器不一致性为(0.288±0.215)ns,带来的水流速度误差最大为2.50×10^(-3)m/s,以上误差可通过数据校正的方法予以修正。在20~40℃范围内,流速的均方差为1.70×10^(-4)m/s,温度对测量结果的影响可忽略不计。在动水试验中,方箱流量计测量相对于电磁流量计偏差为0.16%~0.93%,达到了与电磁流量计同等的测量精度。研究结果可为精确测量灌渠流量、实现高效节水灌溉提供技术支撑。
