为计算直流应急电网不同故障类型下的短路电流,便于直流应急电网开关器件的型号以及相应的保护措施的选择,提出了一种考虑蓄电池Run-time等效模型的船舶直流应急电网短路电流计算方法。与传统蓄电池的Thevenin等效模型和PNGV(the partne...为计算直流应急电网不同故障类型下的短路电流,便于直流应急电网开关器件的型号以及相应的保护措施的选择,提出了一种考虑蓄电池Run-time等效模型的船舶直流应急电网短路电流计算方法。与传统蓄电池的Thevenin等效模型和PNGV(the partnership for a new generation of vehicles)等效模型相比,所提方法考虑了蓄电池容量衰减、温度、循环次数、存储时长、电流倍率、自身产热等多因素的影响,对蓄电池的故障等值电路进行了精确模拟。最后,利用实际的直流应急电网短路电流仿真和实验验证了所提方法的准确性,与Thevenin等效模型和PNGV等效模型相比,不同故障下蓄电池Run-time等效模型短路电流的计算误差更小。展开更多
3-D Networks-on-Chip （NoC） emerge as a potent solution to address both the interconnection and design complexity problems facing future Multiprocessor System-on-Chips （MPSoCs）. Effective run-time mapping on such 3...3-D Networks-on-Chip （NoC） emerge as a potent solution to address both the interconnection and design complexity problems facing future Multiprocessor System-on-Chips （MPSoCs）. Effective run-time mapping on such 3-D NoC-based MPSoCs can be quite challenging, as the arrival order and task graphs of the target applications are typically not known a priori, which can be further complicated by stringent energy requirements for NoC systems. This paper thus presents an energy-aware run-time incremental mapping algorithm （ERIM） for 3-D NoC which can minimize the energy consumption due to the data communications among processor cores, while reducing the fragmentation effect on the incoming applications to be mapped, and simultaneously satisfying the thermal constraints imposed on each incoming application. Specifically, incoming applications are mapped to cuboid tile regions for lower energy consumption of communication and the minimal routing. Fragment tiles due to system fragmentation can be gleaned for better resource utilization. Extensive experiments have been conducted to evaluate the performance of the proposed algorithm ERIM, and the results are compared against the optimal mapping algorithm （branch-and-bound） and two heuristic algorithms （TB and TL）. The experiments show that ERIM outperforms TB and TL methods with significant energy saving （more than 10%）, much reduced average response time, and improved system utilization.展开更多
The run-time security guarantee is a hotspot in current cyberspace security research, especially on embedded terminals, such as smart hardware as well as wearable and mobile devices. Typically, these devices use unive...The run-time security guarantee is a hotspot in current cyberspace security research, especially on embedded terminals, such as smart hardware as well as wearable and mobile devices. Typically, these devices use universal hardware and software to connect with public networks via the Internet, and are probably open to security threats from Trojan viruses and other malware. As a result, the security of sensitive personal data is threatened and economic interests in the industry are compromised. To address the run-time security problems efficiently, first, a TrustEnclave-based secure architecture is proposed, and the trusted execution environment is constructed by hardware isolation technology. Then the prototype system is implemented on real TrustZone-enabled hardware devices. Finally, both analytical and experimental evaluations are provided. The experimental results demonstrate the effectiveness and feasibility of the proposed security scheme.展开更多
Real-time multi-media applications are increasingly mapped on modern embedded systems based on multiprocessor systems-on-chip （MPSoC）. Tasks of the applications need to be mapped on the MPSoC resources efficiently i...Real-time multi-media applications are increasingly mapped on modern embedded systems based on multiprocessor systems-on-chip （MPSoC）. Tasks of the applications need to be mapped on the MPSoC resources efficiently in order to satisity their performance constraints. Exploring all the possible mappings, i.e., tasks to resources combinations exhaustively may take days or weeks. Additionally, the exploration is performed at design-time, which cannot handle dynamism in applications and resources＇ status. A runtime mapping technique can cater for the dynamism but cannot guarantee for strict timing deadlines due to large computations involved at run-time. Thus, an approach performing feasible compute intensive exploration at design-time and using the explored results at run-time is required. This paper presents a solution in the same direction. Communicationaware design space exploration （CADSE） techniques have been proposed to explore different mapping options to be selected at run-time subject to desired performance and available MPSoC resources. Experiments show that the proposed techniques for exploration are faster over an exhaustive exploration and provides almost the same quality of results.展开更多
Cyber physical systems(CPSs) incorporate computation, communication, and physical processes. The deep coupling and continuous interaction between such processes lead to a significant increase in complexity in the desi...Cyber physical systems(CPSs) incorporate computation, communication, and physical processes. The deep coupling and continuous interaction between such processes lead to a significant increase in complexity in the design and implementation of CPSs. Consequently, whereas developing CPSs from scratch is inefficient, developing them with the aid of CPS run-time supporting platforms can be efficient. In recent years, much research has been actively conducted on CPS run-time supporting platforms. However, few surveys have been conducted on these platforms. In this paper, we analyze and evaluate existing CPS run-time supporting platforms by first classifying them into three categories from the viewpoint of software architecture: component-based platforms, service-based platforms, and agent-based platforms. Then, for each type, we detail its design philosophy, key technical problems, and corresponding solutions with specific use cases. Subsequently, we compare existing platforms from two aspects: construction approaches for CPS tasks and support for non-functional properties. Finally, we outline several important future research issues.展开更多
文摘为计算直流应急电网不同故障类型下的短路电流,便于直流应急电网开关器件的型号以及相应的保护措施的选择,提出了一种考虑蓄电池Run-time等效模型的船舶直流应急电网短路电流计算方法。与传统蓄电池的Thevenin等效模型和PNGV(the partnership for a new generation of vehicles)等效模型相比,所提方法考虑了蓄电池容量衰减、温度、循环次数、存储时长、电流倍率、自身产热等多因素的影响,对蓄电池的故障等值电路进行了精确模拟。最后,利用实际的直流应急电网短路电流仿真和实验验证了所提方法的准确性,与Thevenin等效模型和PNGV等效模型相比,不同故障下蓄电池Run-time等效模型短路电流的计算误差更小。
基金This work is supported by the National Natural Science Foundation of China under Grant Nos. 60873112 and 61028004, the National Natural Science Foundation of USA under Grant No. CNS-1126688.
文摘3-D Networks-on-Chip （NoC） emerge as a potent solution to address both the interconnection and design complexity problems facing future Multiprocessor System-on-Chips （MPSoCs）. Effective run-time mapping on such 3-D NoC-based MPSoCs can be quite challenging, as the arrival order and task graphs of the target applications are typically not known a priori, which can be further complicated by stringent energy requirements for NoC systems. This paper thus presents an energy-aware run-time incremental mapping algorithm （ERIM） for 3-D NoC which can minimize the energy consumption due to the data communications among processor cores, while reducing the fragmentation effect on the incoming applications to be mapped, and simultaneously satisfying the thermal constraints imposed on each incoming application. Specifically, incoming applications are mapped to cuboid tile regions for lower energy consumption of communication and the minimal routing. Fragment tiles due to system fragmentation can be gleaned for better resource utilization. Extensive experiments have been conducted to evaluate the performance of the proposed algorithm ERIM, and the results are compared against the optimal mapping algorithm （branch-and-bound） and two heuristic algorithms （TB and TL）. The experiments show that ERIM outperforms TB and TL methods with significant energy saving （more than 10%）, much reduced average response time, and improved system utilization.
基金supported by the National Natural Science Foundation of China (Nos.61572516 and 61503213)
文摘The run-time security guarantee is a hotspot in current cyberspace security research, especially on embedded terminals, such as smart hardware as well as wearable and mobile devices. Typically, these devices use universal hardware and software to connect with public networks via the Internet, and are probably open to security threats from Trojan viruses and other malware. As a result, the security of sensitive personal data is threatened and economic interests in the industry are compromised. To address the run-time security problems efficiently, first, a TrustEnclave-based secure architecture is proposed, and the trusted execution environment is constructed by hardware isolation technology. Then the prototype system is implemented on real TrustZone-enabled hardware devices. Finally, both analytical and experimental evaluations are provided. The experimental results demonstrate the effectiveness and feasibility of the proposed security scheme.
基金The authors would like to thank the reviewers for their feedback and suggestions. We also wish to mention that this work is partly supported by Singapore Ministry of Education Academic Research Fund Tier 1 （R-263-000-655-133） and National Natural Science Foundation of China （NSFC） （Grant No. 61173032）.
文摘Real-time multi-media applications are increasingly mapped on modern embedded systems based on multiprocessor systems-on-chip （MPSoC）. Tasks of the applications need to be mapped on the MPSoC resources efficiently in order to satisity their performance constraints. Exploring all the possible mappings, i.e., tasks to resources combinations exhaustively may take days or weeks. Additionally, the exploration is performed at design-time, which cannot handle dynamism in applications and resources＇ status. A runtime mapping technique can cater for the dynamism but cannot guarantee for strict timing deadlines due to large computations involved at run-time. Thus, an approach performing feasible compute intensive exploration at design-time and using the explored results at run-time is required. This paper presents a solution in the same direction. Communicationaware design space exploration （CADSE） techniques have been proposed to explore different mapping options to be selected at run-time subject to desired performance and available MPSoC resources. Experiments show that the proposed techniques for exploration are faster over an exhaustive exploration and provides almost the same quality of results.
基金supported by the Integrated Science-Technology Innovation Plan of Shaanxi Province,China(No.2015KTZDGY06-03)
文摘Cyber physical systems(CPSs) incorporate computation, communication, and physical processes. The deep coupling and continuous interaction between such processes lead to a significant increase in complexity in the design and implementation of CPSs. Consequently, whereas developing CPSs from scratch is inefficient, developing them with the aid of CPS run-time supporting platforms can be efficient. In recent years, much research has been actively conducted on CPS run-time supporting platforms. However, few surveys have been conducted on these platforms. In this paper, we analyze and evaluate existing CPS run-time supporting platforms by first classifying them into three categories from the viewpoint of software architecture: component-based platforms, service-based platforms, and agent-based platforms. Then, for each type, we detail its design philosophy, key technical problems, and corresponding solutions with specific use cases. Subsequently, we compare existing platforms from two aspects: construction approaches for CPS tasks and support for non-functional properties. Finally, we outline several important future research issues.
文摘[目的]探究实时姿势监测与反馈系统对血流限制(blood flow restriction,BFR)下跑者下肢运动学与肌电特征的变化.[方法]17名无BFR训练经验的新手健康跑者参与3次不同方案的跑步测试.第1次测试空白条件下单纯跑步(blank running,BR)状态;第2次测试BFR下跑步(BFR and running,BFRR)状态;第3次测试BFR并进行实时姿势监测与反馈(monitoring and feedback,MF)时的跑步状态.比较3次测试中跑者下肢髋、膝、踝关节峰值活动角度与下肢主要肌肉肌电参数变化.[结果]与BR方案相比,BFRR方案下跑者下肢关节峰值角度显著增加,肌肉激活程度与肌纤维募集频率范围也显著增加.使用实时姿势监测与反馈后,与BFRR方案相比,BFRR+MF方案下跑者下肢关节峰值活动角度与上述肌电参数显著下降.[结论]BFR训练将导致跑者初次应用时表现出过激运动表现,但实时监测与反馈系统将优化运动表现,降低运动损伤风险.
