The signal integrity problem in 0.18μm CMOS technology is analyzed from simulation.Several rules in this phenomenon are found by analyzing the crosstalk delay and noise,which are helpful for the future circuit design.
According to the failure characteristics of aircraft structure, a delay-time model is an effective method to optimize maintenance for aircraft structure. To imitate the practical situation as much as possible, imperfe...According to the failure characteristics of aircraft structure, a delay-time model is an effective method to optimize maintenance for aircraft structure. To imitate the practical situation as much as possible, imperfect inspections, thresholds and repeated intervals are concerned in delay-time models. Since the suggestion by the existing delay-time models that the inspections are implemented in an infinite time span lacks practical value, a de- lay-time model with imperfect inspection within a finite time span is proposed. In the model, the nonhomogenous Poisson process is adopted to obtain the renewal probabilities between two different successive inspections on de- fects or failures. An algorithm is applied based on the Nelder-Mead downhill simplex method to solve the model. Finally, a numerical example proves the validity and effectiveness of the model.展开更多
Robust stabilization for a class of nonlinear uncertain neutral system with time-varying delay is investigated. By applying the Lyapunov stability theorem, an adaptive sliding mode controller （ADSMC） is developed.Ba...Robust stabilization for a class of nonlinear uncertain neutral system with time-varying delay is investigated. By applying the Lyapunov stability theorem, an adaptive sliding mode controller （ADSMC） is developed.Based on the sliding mode control technique, the controller can drive the system into a pre-specified sliding hyperplane to obtain the desired dynamic performance. Once the system dynamics reaches the sliding plane, the control system is insensitive to uncertainty. The adaptive technique can overcome the unknown upper bound of uncertainty so that the reaching condition can be satisfied. Furthermore, the controller does not include any delayed state,so such an ADSMC is memoryless. Finally, a numerical example is given to verify the validity of the developed memoryless ADSMC and the globally asymptotic stability is guaranteed for the control scheme.展开更多
To reduce the error in transfer alignment caused by reference information delay,a time delay estimation method is developed based on least-squares curve fitting of the angular rate integration.First,the gyro sensor me...To reduce the error in transfer alignment caused by reference information delay,a time delay estimation method is developed based on least-squares curve fitting of the angular rate integration.First,the gyro sensor measurements of the main strapdown inertial navigation system（M-SINS） and the slave strapdown inertial navigation system（S-SINS） are recorded for a few seconds and the integration of the data is calculated.Then,the possible maximum range of the delay value is defined and the points of the curve at different intervals are moved.The square of the differences between the corresponding points are calculated.Finally,the delay estimation can be acquired by the least-squares curve fitting of the M-SINS and the S-SINS.A delay compensation method by local data shifting is also presented.The simulation results demonstrate the effectiveness of delay estimation and indicate that the estimation accuracy is independent of the delay value.And the local data shifting compensation method can effectively reduce the errors of the transfer alignment caused by the reference information delay.展开更多
In order to improve the performance of multipath mitigation in tracking Galileo signals, a new multipath mitigation method named early-late strobe correlator （ELSC） is proposed. By applying the strobe correlator use...In order to improve the performance of multipath mitigation in tracking Galileo signals, a new multipath mitigation method named early-late strobe correlator （ELSC） is proposed. By applying the strobe correlator used widely in global positioning system （GPS） scenarios to Galileo E1 signals, it can be found that the strobe correlator has an undesirable level of performance when the delay of multipath signals is about 0. 5 chip. Combining several strobe correlators, the ELSC can effectively mitigate the multipath effect especially for the multipath signals with the 0. 5 chip delay. The multipath error envelopes between the strobe correlator and the ELSC are compared for Galileo E1 signals. The simulation results indicate that the ELSC performs excellently on multipath mitigation, and can be applied in both Galileo scenarios and GPS scenarios.展开更多
A mode for the periodicity and weakening surge in semi-insulating GaAs photoconductive semiconductor switches is proposed based on the transferred-electron effect. It is shown that the periodicity and weakening surge ...A mode for the periodicity and weakening surge in semi-insulating GaAs photoconductive semiconductor switches is proposed based on the transferred-electron effect. It is shown that the periodicity and weakening surge is caused by the interaction between the self-excitation of the resonant circuit and transferred electron oscillation of the switch. The bias electric field （larger than Gunn threshold） across the switch is modulated by the AC elec-tric field,when the instantaneous bias electric field E is swinging below Gunn electric field threshold ET but grea-ter than the sustaining field Es （the minimum electric field required to support the domain） at the time of the do-main reaching the anode, and then the delayed-dipole domain mode of switch is obtained. It is the photon-activated carriers that satisfy the requirement of charge domain formation on carrier concentration and device length prod-uct of 10^12 cm^-2,and the semi-insulating GaAs photoconductive semiconductor switch is essentially a type of pho-ton-activated charge domain device.展开更多
The properties and the design of PWM systems are discussed. The relations among the orifice areas of the valves, initial times and the rate of piston areas are deduced. Also a PWM system is designed and some experimen...The properties and the design of PWM systems are discussed. The relations among the orifice areas of the valves, initial times and the rate of piston areas are deduced. Also a PWM system is designed and some experiments are done. The experiment results agree with those of theory analyses. It can be shown that the relations are correct and the conclusion of theory analyses is reasonable.展开更多
[Objective] The research aimed to study the effects of magnetic stress on the delayed luminescence of mung bean leaves.[Method]With mung bean leaves as the experimental materials,the delayed luminescence curve of mung...[Objective] The research aimed to study the effects of magnetic stress on the delayed luminescence of mung bean leaves.[Method]With mung bean leaves as the experimental materials,the delayed luminescence curve of mung bean leaves under the same magnetic field intensity at different processing time was measured by using BPCL-type weak luminescence measuring instrument.[Result] The absorption of the magnetic field stimulation within the leaves had its own rules.A certain magnetic field intensity and a certain...展开更多
The field measurements of decay rates and time lags of heat conduction in a building construction taken in Nanjing during the summer of 2001 are presented.The decay rates and time lags are calculated according to the ...The field measurements of decay rates and time lags of heat conduction in a building construction taken in Nanjing during the summer of 2001 are presented.The decay rates and time lags are calculated according to the frequency responses of the heat absorbed by the room＇s internal surfaces,inside surface temperature,indoor air temperature and outdoor synthetic temperature.The measured results match very well with the theoretical results of the zeroth and the first order values of the decay rates and time lags of heat conduction in the building construction,but the difference between the measured values and the theoretical values for the second order is too great to be accepted.It is therefore difficult to accurately test the second order value.However,it is still advisable to complete the analysis using the zeroth-and the first-orders values of the decay rates and time lags of heat conduction in building construction under field conditions,because in these cases the decay rates of heat conduction reach twenty which meets the requirements of engineering plans.展开更多
The design and implementation of a novel ADC architecture called ring-ADC for digital voltage regulator module controllers are presented. Based on the principle of voltage-controlled oscillators＇ transform from volta...The design and implementation of a novel ADC architecture called ring-ADC for digital voltage regulator module controllers are presented. Based on the principle of voltage-controlled oscillators＇ transform from voltage to frequency,the A/D conversion of ring-ADC achieves good linearity and precise calibration against process variations compared with the delay-line ADC. A differential pulse counting discriminator also helps decrease the power consumption of the ring-ADC. It is fabricated with a Chartered 0.35μm CMOS process, and the measurement results of the integral and differential nonlinearity performance are 0.92LSB and 1.2LSB respectively. The maximum gain error measured in ten sample chips is ± 3.85%. With sampling rate of 500kHz and when the voltage regulator module （VRM） works in steady state, the ring-ADC＇s average power consumption is 2.56mW. The ring-ADC is verified to meet the requirements for digital VRM controller application.展开更多
Based on architecture analysis of island-style F PGA,area and delay models of LUT FPGA are proposed.The models are used to analyze the effect of LUT size on FPGA area and performance.Results show optimal LUT size obta...Based on architecture analysis of island-style F PGA,area and delay models of LUT FPGA are proposed.The models are used to analyze the effect of LUT size on FPGA area and performance.Results show optimal LUT size obtained by computation models is the same as that from experiments:a LUT size of 4 produces the best area results,and a LUT size of 5 provides the better performance.展开更多
文摘The signal integrity problem in 0.18μm CMOS technology is analyzed from simulation.Several rules in this phenomenon are found by analyzing the crosstalk delay and noise,which are helpful for the future circuit design.
基金Supported by the National Natural Science Foundation of China(61079013)the Natural Science Fund Project in Jiangsu Province(BK2011737)~~
文摘According to the failure characteristics of aircraft structure, a delay-time model is an effective method to optimize maintenance for aircraft structure. To imitate the practical situation as much as possible, imperfect inspections, thresholds and repeated intervals are concerned in delay-time models. Since the suggestion by the existing delay-time models that the inspections are implemented in an infinite time span lacks practical value, a de- lay-time model with imperfect inspection within a finite time span is proposed. In the model, the nonhomogenous Poisson process is adopted to obtain the renewal probabilities between two different successive inspections on de- fects or failures. An algorithm is applied based on the Nelder-Mead downhill simplex method to solve the model. Finally, a numerical example proves the validity and effectiveness of the model.
文摘Robust stabilization for a class of nonlinear uncertain neutral system with time-varying delay is investigated. By applying the Lyapunov stability theorem, an adaptive sliding mode controller （ADSMC） is developed.Based on the sliding mode control technique, the controller can drive the system into a pre-specified sliding hyperplane to obtain the desired dynamic performance. Once the system dynamics reaches the sliding plane, the control system is insensitive to uncertainty. The adaptive technique can overcome the unknown upper bound of uncertainty so that the reaching condition can be satisfied. Furthermore, the controller does not include any delayed state,so such an ADSMC is memoryless. Finally, a numerical example is given to verify the validity of the developed memoryless ADSMC and the globally asymptotic stability is guaranteed for the control scheme.
基金The National Basic Research Program of China(973 Program) (No. 613121030201)the Fundamental Research of Commission of Science,Technology and Industry for National Defense (No. C1420080224)
文摘To reduce the error in transfer alignment caused by reference information delay,a time delay estimation method is developed based on least-squares curve fitting of the angular rate integration.First,the gyro sensor measurements of the main strapdown inertial navigation system（M-SINS） and the slave strapdown inertial navigation system（S-SINS） are recorded for a few seconds and the integration of the data is calculated.Then,the possible maximum range of the delay value is defined and the points of the curve at different intervals are moved.The square of the differences between the corresponding points are calculated.Finally,the delay estimation can be acquired by the least-squares curve fitting of the M-SINS and the S-SINS.A delay compensation method by local data shifting is also presented.The simulation results demonstrate the effectiveness of delay estimation and indicate that the estimation accuracy is independent of the delay value.And the local data shifting compensation method can effectively reduce the errors of the transfer alignment caused by the reference information delay.
基金The National Key Technology R&D Program of China during the 11th Five-Year Plan Period(No.2008BAJ11B05)
文摘In order to improve the performance of multipath mitigation in tracking Galileo signals, a new multipath mitigation method named early-late strobe correlator （ELSC） is proposed. By applying the strobe correlator used widely in global positioning system （GPS） scenarios to Galileo E1 signals, it can be found that the strobe correlator has an undesirable level of performance when the delay of multipath signals is about 0. 5 chip. Combining several strobe correlators, the ELSC can effectively mitigate the multipath effect especially for the multipath signals with the 0. 5 chip delay. The multipath error envelopes between the strobe correlator and the ELSC are compared for Galileo E1 signals. The simulation results indicate that the ELSC performs excellently on multipath mitigation, and can be applied in both Galileo scenarios and GPS scenarios.
文摘A mode for the periodicity and weakening surge in semi-insulating GaAs photoconductive semiconductor switches is proposed based on the transferred-electron effect. It is shown that the periodicity and weakening surge is caused by the interaction between the self-excitation of the resonant circuit and transferred electron oscillation of the switch. The bias electric field （larger than Gunn threshold） across the switch is modulated by the AC elec-tric field,when the instantaneous bias electric field E is swinging below Gunn electric field threshold ET but grea-ter than the sustaining field Es （the minimum electric field required to support the domain） at the time of the do-main reaching the anode, and then the delayed-dipole domain mode of switch is obtained. It is the photon-activated carriers that satisfy the requirement of charge domain formation on carrier concentration and device length prod-uct of 10^12 cm^-2,and the semi-insulating GaAs photoconductive semiconductor switch is essentially a type of pho-ton-activated charge domain device.
文摘The properties and the design of PWM systems are discussed. The relations among the orifice areas of the valves, initial times and the rate of piston areas are deduced. Also a PWM system is designed and some experiments are done. The experiment results agree with those of theory analyses. It can be shown that the relations are correct and the conclusion of theory analyses is reasonable.
文摘[Objective] The research aimed to study the effects of magnetic stress on the delayed luminescence of mung bean leaves.[Method]With mung bean leaves as the experimental materials,the delayed luminescence curve of mung bean leaves under the same magnetic field intensity at different processing time was measured by using BPCL-type weak luminescence measuring instrument.[Result] The absorption of the magnetic field stimulation within the leaves had its own rules.A certain magnetic field intensity and a certain...
基金The Advance Research Projects of Southeast Universityfor the National Natural Science Foundation of China(No.XJ0701262)the National Key Technologies R&D Program of China during the 11th Five-Year Plan Period(No.2008BAJ12B04,2008BAJ12B05,2006BAJ03A04)
文摘The field measurements of decay rates and time lags of heat conduction in a building construction taken in Nanjing during the summer of 2001 are presented.The decay rates and time lags are calculated according to the frequency responses of the heat absorbed by the room＇s internal surfaces,inside surface temperature,indoor air temperature and outdoor synthetic temperature.The measured results match very well with the theoretical results of the zeroth and the first order values of the decay rates and time lags of heat conduction in the building construction,but the difference between the measured values and the theoretical values for the second order is too great to be accepted.It is therefore difficult to accurately test the second order value.However,it is still advisable to complete the analysis using the zeroth-and the first-orders values of the decay rates and time lags of heat conduction in building construction under field conditions,because in these cases the decay rates of heat conduction reach twenty which meets the requirements of engineering plans.
文摘The design and implementation of a novel ADC architecture called ring-ADC for digital voltage regulator module controllers are presented. Based on the principle of voltage-controlled oscillators＇ transform from voltage to frequency,the A/D conversion of ring-ADC achieves good linearity and precise calibration against process variations compared with the delay-line ADC. A differential pulse counting discriminator also helps decrease the power consumption of the ring-ADC. It is fabricated with a Chartered 0.35μm CMOS process, and the measurement results of the integral and differential nonlinearity performance are 0.92LSB and 1.2LSB respectively. The maximum gain error measured in ten sample chips is ± 3.85%. With sampling rate of 500kHz and when the voltage regulator module （VRM） works in steady state, the ring-ADC＇s average power consumption is 2.56mW. The ring-ADC is verified to meet the requirements for digital VRM controller application.
文摘Based on architecture analysis of island-style F PGA,area and delay models of LUT FPGA are proposed.The models are used to analyze the effect of LUT size on FPGA area and performance.Results show optimal LUT size obtained by computation models is the same as that from experiments:a LUT size of 4 produces the best area results,and a LUT size of 5 provides the better performance.
