the Information-Centric Networking(ICN) paradigm is proved to have the advantages of decreasing data delivery latency, enhancing user mobility, etc. However, current implementations of ICN require changing the infrast...the Information-Centric Networking(ICN) paradigm is proved to have the advantages of decreasing data delivery latency, enhancing user mobility, etc. However, current implementations of ICN require changing the infrastructure of Internet, which hinders its deployment and development. Meanwhile, Software Defined Networking(SDN) emerges as a viable solution to facilitate the deployment of new network paradigm without disrupting production traffic by decoupling the control plane from data forwarding plane. In this paper, the essential properties which reflect ICN working principles are summarized, and a framework called SDICN is designed in accordance to the SDN philosophy. The algorithmic frameworks of SDICN which can satisfy the essential properties are designed based on the programmability and virtualization functions of SDN. Based on Open Flow and data center technology, a prototype of SDICN is implemented. By comparing the performance with the CCNx, the SDICN is proved to be feasibility and availability.展开更多
Wide area damping controller(WADC) is usually utilized to damp interarea low frequency oscillation in power system. However, conventional WADC design method neglects the influence of signal transmission delay and damp...Wide area damping controller(WADC) is usually utilized to damp interarea low frequency oscillation in power system. However, conventional WADC design method neglects the influence of signal transmission delay and damping performance of WADC designed by the conventional method may deteriorate or even has no effect when signal transmission delay is beyond delay margin, an index that denotes delay endurance degree of power system. Therefore, a new design method for WADC under the condition of expected damping factor and required signal transmission delay is presented in this work. An improved delay margin with less conservatism is derived by adopting a new Lyapunov-Krasovskii function and more compact bounding technique on the derivative of Lyapunov-Krasovskii functional. The improved delay margin, which constructs the correlation of damping factor and signal transmission delay, can be used to design WADC. WADC designed by the proposed method can ensure that power system satisfies expected damping factor when WADC input signal is delayed within delay margin. Satisfactory test results demonstrate the effectiveness of the proposed method.展开更多
The motivation of this work is to obtain single PI/PID tuning formula for different types of processes with enhanced disturbance rejection performance. The proposed tuning formula consistently gives better performance...The motivation of this work is to obtain single PI/PID tuning formula for different types of processes with enhanced disturbance rejection performance. The proposed tuning formula consistently gives better performance in comparison to several well-known methods at the same degree of robustness for stable, integrating and unstable processes. For the selection of the closed-loop time constant(τc), a guideline is provided over a broad range of time-delay/time-constant ratios on the basis of the peak of maximum sensitivity(Ms). An analysis has been performed for the uncertainty margin with the different process parameters for the robust controller design. It gives the guideline of the Ms-value settings for the PI controller designs based on the process parameters uncertainty. Furthermore, a relationship has been developed between Ms-value and uncertainty margin with the different process parameters(k, τ and θ). Simulation study has been conducted for the broad class of processes and the controllers are tuned to have the same degree of robustness by measuring the maximum sensitivity, Ms, in order to obtain a reasonable comparison.展开更多
This paper discussed the importance of the delayed neutron detection system.We improved the delayed neutron detection station and delayed neutron detector,so the noise was greatly decreased and the detection efficienc...This paper discussed the importance of the delayed neutron detection system.We improved the delayed neutron detection station and delayed neutron detector,so the noise was greatly decreased and the detection efficiency was greatly increased.After the improvement the stability of the detector was enhanced and the false alarm was eliminated.We introduced the principle of the gas lift pump designed for the sodium cooled fast reactor.A calculation model of the failed fuel detection system of CEFR was proposed,and from the model a code using LabWindows/CVI was developed.The minimum broken area that could be detected by the delayed neutron detection system of CEFR was calculated and the delayed neutron detection signal in a few representative transient conditions during fuel failure happened was stimulated.展开更多
Wireless Body Area Network(WBAN) is the most promising technology in e-health applications.Energy efficiency stands out as the paramount issue for WBAN.In this paper,an energy efficient MAC protocol named Quasi-Sleep-...Wireless Body Area Network(WBAN) is the most promising technology in e-health applications.Energy efficiency stands out as the paramount issue for WBAN.In this paper,an energy efficient MAC protocol named Quasi-Sleep-Preempt-Supported(QSPS) is proposed.The protocol is mainly TDMA-based:nodes transmit packets in the allocated slots,while entering the Q-Sleep mode in other slots.Moreover,for a node with emergency packet,it can broadcast a special designed Awakening Message to wake up the whole network and preempts the right to use the current slot to transmit that emergency packet,thus decreasing delay.Compared with relevant protocols,QS-PS can achieve high energy efficiency and decrease the delay of both normal packets and emergency packets.展开更多
Since single event transient pulse quenching can reduce the SET(single event transient) pulsewidths effectively,the charge collected by passive device should be maximized in order to minimize the propagated SET.From t...Since single event transient pulse quenching can reduce the SET(single event transient) pulsewidths effectively,the charge collected by passive device should be maximized in order to minimize the propagated SET.From the perspective of the layout and circuit design,the SET pulsewidths can be greatly inhibited by minimizing the layout spacing and signal propagation delay,which sheds new light on the radiation-hardened ICs(integrated circuits) design.Studies show that the SET pulsewidths of propagation are not in direct proportion to the LET(linear energy transfer) of incident particles,thus the defining of the LET threshold should be noted when SET/SEU(single event upset) occurs for the radiation-hardened design.The capability of anti-radiation meets the demand when LET is high but some soft errors may occur when LET is low.Therefore,radiation experiments should be focused on evaluating the LET that demonstrates the worst response to the circuit.展开更多
As gas recirculation constitutes a fundamental condition for the realization of MILD combustion, it is necessary to determine gas recirculation ratio before designing MILD combustor. MILD combustion model with gas rec...As gas recirculation constitutes a fundamental condition for the realization of MILD combustion, it is necessary to determine gas recirculation ratio before designing MILD combustor. MILD combustion model with gas recirculation was used in this simulation work to evaluate the effect of fuel type and pressure on threshold gas recirculation ratio of MILD mode. Ignition delay time is also an important design parameter for gas turbine combustor, this parameter is kinetically studied to analyze the effect of pressure on MILD mixture ignition. Threshold gas recirculation ratio of hydrogen MILD combustion changes slightly and is nearly equal to that of 10 MJ/Nm3syngas in the pressure range of 1-19 atm, under the conditions of 298 K fresh reactant temperature and 1373 K exhaust gas temperature, indicating that MILD regime is fuel flexible. Ignition delay calculation results show that pressure has a negative effect on ignition delay time of 10 MJ/Nm3syngas MILD mixture, because OH mole fraction in MILD mixture drops down as pressure increases, resulting in the delay of the oxidation process.展开更多
基金supported by the State Key Development Program for Basic Research of China under Grant No.2012CB315806National Natural Science Foundation of China(No.61379149,No.61402521 and No.61103225)+1 种基金Natural Science Foundation of Jiangsu(BK 20140070,BK20140068)Jiangsu Future Network Innovation Institute Research Project on Future Networks(BY2013095-1-06)
文摘the Information-Centric Networking(ICN) paradigm is proved to have the advantages of decreasing data delivery latency, enhancing user mobility, etc. However, current implementations of ICN require changing the infrastructure of Internet, which hinders its deployment and development. Meanwhile, Software Defined Networking(SDN) emerges as a viable solution to facilitate the deployment of new network paradigm without disrupting production traffic by decoupling the control plane from data forwarding plane. In this paper, the essential properties which reflect ICN working principles are summarized, and a framework called SDICN is designed in accordance to the SDN philosophy. The algorithmic frameworks of SDICN which can satisfy the essential properties are designed based on the programmability and virtualization functions of SDN. Based on Open Flow and data center technology, a prototype of SDICN is implemented. By comparing the performance with the CCNx, the SDICN is proved to be feasibility and availability.
基金Project(51007042) supported by the National Natural Science Foundation of China
文摘Wide area damping controller(WADC) is usually utilized to damp interarea low frequency oscillation in power system. However, conventional WADC design method neglects the influence of signal transmission delay and damping performance of WADC designed by the conventional method may deteriorate or even has no effect when signal transmission delay is beyond delay margin, an index that denotes delay endurance degree of power system. Therefore, a new design method for WADC under the condition of expected damping factor and required signal transmission delay is presented in this work. An improved delay margin with less conservatism is derived by adopting a new Lyapunov-Krasovskii function and more compact bounding technique on the derivative of Lyapunov-Krasovskii functional. The improved delay margin, which constructs the correlation of damping factor and signal transmission delay, can be used to design WADC. WADC designed by the proposed method can ensure that power system satisfies expected damping factor when WADC input signal is delayed within delay margin. Satisfactory test results demonstrate the effectiveness of the proposed method.
基金the support provided by King Abdulaziz City for Science and Technology (KACST) through the "KACST Annual Program" at King Fahd University of Petroleum & Minerals (KFUPM) for funding this work through project number AT-32-41
文摘The motivation of this work is to obtain single PI/PID tuning formula for different types of processes with enhanced disturbance rejection performance. The proposed tuning formula consistently gives better performance in comparison to several well-known methods at the same degree of robustness for stable, integrating and unstable processes. For the selection of the closed-loop time constant(τc), a guideline is provided over a broad range of time-delay/time-constant ratios on the basis of the peak of maximum sensitivity(Ms). An analysis has been performed for the uncertainty margin with the different process parameters for the robust controller design. It gives the guideline of the Ms-value settings for the PI controller designs based on the process parameters uncertainty. Furthermore, a relationship has been developed between Ms-value and uncertainty margin with the different process parameters(k, τ and θ). Simulation study has been conducted for the broad class of processes and the controllers are tuned to have the same degree of robustness by measuring the maximum sensitivity, Ms, in order to obtain a reasonable comparison.
文摘This paper discussed the importance of the delayed neutron detection system.We improved the delayed neutron detection station and delayed neutron detector,so the noise was greatly decreased and the detection efficiency was greatly increased.After the improvement the stability of the detector was enhanced and the false alarm was eliminated.We introduced the principle of the gas lift pump designed for the sodium cooled fast reactor.A calculation model of the failed fuel detection system of CEFR was proposed,and from the model a code using LabWindows/CVI was developed.The minimum broken area that could be detected by the delayed neutron detection system of CEFR was calculated and the delayed neutron detection signal in a few representative transient conditions during fuel failure happened was stimulated.
基金supported in part by National Natural Science Foundation of China(NSFC,No.61325012,6171219,6122001,61202373)
文摘Wireless Body Area Network(WBAN) is the most promising technology in e-health applications.Energy efficiency stands out as the paramount issue for WBAN.In this paper,an energy efficient MAC protocol named Quasi-Sleep-Preempt-Supported(QSPS) is proposed.The protocol is mainly TDMA-based:nodes transmit packets in the allocated slots,while entering the Q-Sleep mode in other slots.Moreover,for a node with emergency packet,it can broadcast a special designed Awakening Message to wake up the whole network and preempts the right to use the current slot to transmit that emergency packet,thus decreasing delay.Compared with relevant protocols,QS-PS can achieve high energy efficiency and decrease the delay of both normal packets and emergency packets.
基金supported by the National Natural Science Foundation of China (Grant Nos. 60836004 and 61006070)
文摘Since single event transient pulse quenching can reduce the SET(single event transient) pulsewidths effectively,the charge collected by passive device should be maximized in order to minimize the propagated SET.From the perspective of the layout and circuit design,the SET pulsewidths can be greatly inhibited by minimizing the layout spacing and signal propagation delay,which sheds new light on the radiation-hardened ICs(integrated circuits) design.Studies show that the SET pulsewidths of propagation are not in direct proportion to the LET(linear energy transfer) of incident particles,thus the defining of the LET threshold should be noted when SET/SEU(single event upset) occurs for the radiation-hardened design.The capability of anti-radiation meets the demand when LET is high but some soft errors may occur when LET is low.Therefore,radiation experiments should be focused on evaluating the LET that demonstrates the worst response to the circuit.
基金supported by National Natural Science Foundation of China(Project No.51006104)National Key Basic Re-search Program of China(No.2014CB247500)
文摘As gas recirculation constitutes a fundamental condition for the realization of MILD combustion, it is necessary to determine gas recirculation ratio before designing MILD combustor. MILD combustion model with gas recirculation was used in this simulation work to evaluate the effect of fuel type and pressure on threshold gas recirculation ratio of MILD mode. Ignition delay time is also an important design parameter for gas turbine combustor, this parameter is kinetically studied to analyze the effect of pressure on MILD mixture ignition. Threshold gas recirculation ratio of hydrogen MILD combustion changes slightly and is nearly equal to that of 10 MJ/Nm3syngas in the pressure range of 1-19 atm, under the conditions of 298 K fresh reactant temperature and 1373 K exhaust gas temperature, indicating that MILD regime is fuel flexible. Ignition delay calculation results show that pressure has a negative effect on ignition delay time of 10 MJ/Nm3syngas MILD mixture, because OH mole fraction in MILD mixture drops down as pressure increases, resulting in the delay of the oxidation process.
