逐次逼近寄存器模数转换器(SAR ADC)在逐次逼近的过程中,电容的切换会使参考电压上出现参考纹波噪声,该噪声会影响比较器的判定,进而输出错误的比较结果。针对该问题,基于CMOS 0.5μm工艺,设计了一种具有纹波消除技术的10 bit SAR ADC...逐次逼近寄存器模数转换器(SAR ADC)在逐次逼近的过程中,电容的切换会使参考电压上出现参考纹波噪声,该噪声会影响比较器的判定,进而输出错误的比较结果。针对该问题,基于CMOS 0.5μm工艺,设计了一种具有纹波消除技术的10 bit SAR ADC。通过增加纹波至比较器输入端的额外路径,将参考纹波满摆幅输入至比较器中;同时设计了消除数模转换器(DAC)模块,对参考纹波进行采样和输入,通过反转纹波噪声的极性,消除参考纹波对ADC输出的影响。该设计将信噪比(SNR)提高到56.75 dB,将有效位数(ENOB)提升到9.14 bit,将积分非线性(INL)从-1~5 LSB降低到-0.2~0.3 LSB,将微分非线性(DNL)从-3~4 LSB降低到-0.5~0.5 LSB。展开更多
According to the analytical characteristics of cubic B spline function,such as compactness and discontinuous smoothness,two methods,Global integral method and Assembling method are proposed to calculate the non-linear...According to the analytical characteristics of cubic B spline function,such as compactness and discontinuous smoothness,two methods,Global integral method and Assembling method are proposed to calculate the non-linear stiffness matrix in the spline finite element method.The Global integral method transforms the integral of the product of spline functions into the sum of boundary data of the product by integral by parts.The Assembling method uses the compactness characteristics of the spline function,reduces the n+3 order stiffness matrix in unit interval to the 4 order matrix,and then obtains the global matrix by assembling the small ones.The two proposed methods are clear in theory and easy to be realized by computer program,which can effectively improve the efficiency of the algorithm for nonlinear spline element method.展开更多
A nonlinear synthesis problem of antennas according to the prescribed power (squared amplitude) radiation pattern (RP) is considered in the variational statement that yields in the possibility to take into account an ...A nonlinear synthesis problem of antennas according to the prescribed power (squared amplitude) radiation pattern (RP) is considered in the variational statement that yields in the possibility to take into account an additional restriction to the synthesized power RP. The problem of synthesis consists of finding such currents in antenna, which generates the RP with the best approximation to the given one. The respective Euler’s equation is reduced on the basis of used functional. This is nonlinear integral equation of Hammerstein’s type. The effective numerical methods are elaborated and applied for its solving. The computational results verify the effectiveness of approach proposed.展开更多
Aim of this work is to analyze and to synthesize acoustic signals emitted by organ pipes. An Independent Component Analysis technique is applied to study the behavior of single notes or chords obtained in real and sim...Aim of this work is to analyze and to synthesize acoustic signals emitted by organ pipes. An Independent Component Analysis technique is applied to study the behavior of single notes or chords obtained in real and simulated environments. These analyses suggest that the pipe acoustic signals can be described by a mixture of nonlinear oscillations obtained by a self-sustained feedback system (i.e., Andronov oscillator). This system allows to obtain a realistic pipe waveform with features very similar to the sound produced by the pipe and to propose an additive synthesis model. Moreover, suitable analogical and integrate circuit models, able to reproduce the registered waveforms and sound, have been designed. A comparison between real and reconstructed acoustic signals is provided.展开更多
作为北京谱仪(Beijing Spectrometer,简称BES)的改造,BESⅢ将把TOF(time-of-flight)测量精度提高到一个新的水平,总时间分辨不大于90ps．其中要求前端电子学(Front End Electronics,FEE)对时间测量的不确定性贡献小于25ps．本文介绍了TO...作为北京谱仪(Beijing Spectrometer,简称BES)的改造,BESⅢ将把TOF(time-of-flight)测量精度提高到一个新的水平,总时间分辨不大于90ps．其中要求前端电子学(Front End Electronics,FEE)对时间测量的不确定性贡献小于25ps．本文介绍了TOF前端读出电子学系统原型电路的设计和初步的测试结果．展开更多
为解决空间辐射环境引起的列并行单斜式模拟数字转换器(analog to digital converter,ADC)中斜坡信号范围不能动态校正的问题,提出一种用于CMOS(complementary metal oxide semiconductor,互补金属氧化物半导体)图像传感器的高精度抗辐...为解决空间辐射环境引起的列并行单斜式模拟数字转换器(analog to digital converter,ADC)中斜坡信号范围不能动态校正的问题,提出一种用于CMOS(complementary metal oxide semiconductor,互补金属氧化物半导体)图像传感器的高精度抗辐射自适应斜坡产生电路设计方法,并对该方法进行了理论分析和验证。仿真实验结果表明:通过dummy像元的设计可以实现输入到输出整个信号环路的闭环自适应负反馈调节;该斜坡产生电路能够在电离总剂量(total ionization dose,TID)效应影响情况下自动调整斜坡信号斜率,从而有效提高斜坡信号的精度。展开更多
This paper proposed and evaluated an estimation method for indoor positioning.The method combines location fingerprinting and dead reckoning differently from the conventional combinations.It uses compound location fin...This paper proposed and evaluated an estimation method for indoor positioning.The method combines location fingerprinting and dead reckoning differently from the conventional combinations.It uses compound location fingerprints,which are composed of radio fingerprints at multiple points of time,that is,at multiple positions,and displacements between them estimated by dead reckoning.To avoid errors accumulated from dead reckoning,the method uses short-range dead reckoning.The method was evaluated using 16 Bluetooth beacons installed in a student room with the dimensions of 11×5 m with furniture inside.The Received Signal Strength Indicator(RSSI)values of the beacons were collected at 30 measuring points,which were points at the intersections on a 1×1 m grid with no obstacles.A compound location fingerprint is composed of RSSI vectors at two points and a displacement vector between them.Random Forests(RF)was used to build regression models to estimate positions from location fingerprints.The root mean square error of position estimation was 0.87 m using 16 Bluetooth beacons.This error is lower than that received with a single-point baseline model,where a feature vector is composed of only RSSI values at one location.The results suggest that the proposed method is effective for indoor positioning.展开更多
This paper presents the characteristics of the crack growth at the interface of rubber-rubber and rubber-steel bimaterials undertensile deformation using the non-linear finite element method. By using the commercial f...This paper presents the characteristics of the crack growth at the interface of rubber-rubber and rubber-steel bimaterials undertensile deformation using the non-linear finite element method. By using the commercial finite element software ABAQUS,the J integral calculations are carried out for the initial interface crack in the interfaces in-between two Neo-Hookean materials,two Mooney-Rivlin materials, Neo-Hookean and Mooney-Rivlin rubbers, Neo-Hookean and Polynomial, Mooney-Rivlin andPolynomial, and the Mooney-Rivlin and steel bi-materials. The computational results of the maximum J integral directionaround the crack tip illustrate the possible direction of crack growth initiation. Furthermore, it is found that the crack bends tothe softer rubber material at a certain angle with the initial crack direction if the crack depth is relatively small. For the crackwith a larger depth, the crack propagates to grow along the interface in-between the bimaterials.展开更多
In this thesis,we establish non-linear wavelet density estimators and studying the asymptotic properties of the estimators with data missing at random when covariates are present.The outstanding advantage of non-linea...In this thesis,we establish non-linear wavelet density estimators and studying the asymptotic properties of the estimators with data missing at random when covariates are present.The outstanding advantage of non-linear wavelet method is estimating the unsoothed functions,however,the classical kernel estimation cannot do this work.At the same time,we study the larger sample properties of the ISE for hazard rate estimator.展开更多
文摘According to the analytical characteristics of cubic B spline function,such as compactness and discontinuous smoothness,two methods,Global integral method and Assembling method are proposed to calculate the non-linear stiffness matrix in the spline finite element method.The Global integral method transforms the integral of the product of spline functions into the sum of boundary data of the product by integral by parts.The Assembling method uses the compactness characteristics of the spline function,reduces the n+3 order stiffness matrix in unit interval to the 4 order matrix,and then obtains the global matrix by assembling the small ones.The two proposed methods are clear in theory and easy to be realized by computer program,which can effectively improve the efficiency of the algorithm for nonlinear spline element method.
文摘A nonlinear synthesis problem of antennas according to the prescribed power (squared amplitude) radiation pattern (RP) is considered in the variational statement that yields in the possibility to take into account an additional restriction to the synthesized power RP. The problem of synthesis consists of finding such currents in antenna, which generates the RP with the best approximation to the given one. The respective Euler’s equation is reduced on the basis of used functional. This is nonlinear integral equation of Hammerstein’s type. The effective numerical methods are elaborated and applied for its solving. The computational results verify the effectiveness of approach proposed.
文摘Aim of this work is to analyze and to synthesize acoustic signals emitted by organ pipes. An Independent Component Analysis technique is applied to study the behavior of single notes or chords obtained in real and simulated environments. These analyses suggest that the pipe acoustic signals can be described by a mixture of nonlinear oscillations obtained by a self-sustained feedback system (i.e., Andronov oscillator). This system allows to obtain a realistic pipe waveform with features very similar to the sound produced by the pipe and to propose an additive synthesis model. Moreover, suitable analogical and integrate circuit models, able to reproduce the registered waveforms and sound, have been designed. A comparison between real and reconstructed acoustic signals is provided.
文摘作为北京谱仪(Beijing Spectrometer,简称BES)的改造,BESⅢ将把TOF(time-of-flight)测量精度提高到一个新的水平,总时间分辨不大于90ps．其中要求前端电子学(Front End Electronics,FEE)对时间测量的不确定性贡献小于25ps．本文介绍了TOF前端读出电子学系统原型电路的设计和初步的测试结果．
文摘为解决空间辐射环境引起的列并行单斜式模拟数字转换器(analog to digital converter,ADC)中斜坡信号范围不能动态校正的问题,提出一种用于CMOS(complementary metal oxide semiconductor,互补金属氧化物半导体)图像传感器的高精度抗辐射自适应斜坡产生电路设计方法,并对该方法进行了理论分析和验证。仿真实验结果表明:通过dummy像元的设计可以实现输入到输出整个信号环路的闭环自适应负反馈调节;该斜坡产生电路能够在电离总剂量(total ionization dose,TID)效应影响情况下自动调整斜坡信号斜率,从而有效提高斜坡信号的精度。
文摘This paper proposed and evaluated an estimation method for indoor positioning.The method combines location fingerprinting and dead reckoning differently from the conventional combinations.It uses compound location fingerprints,which are composed of radio fingerprints at multiple points of time,that is,at multiple positions,and displacements between them estimated by dead reckoning.To avoid errors accumulated from dead reckoning,the method uses short-range dead reckoning.The method was evaluated using 16 Bluetooth beacons installed in a student room with the dimensions of 11×5 m with furniture inside.The Received Signal Strength Indicator(RSSI)values of the beacons were collected at 30 measuring points,which were points at the intersections on a 1×1 m grid with no obstacles.A compound location fingerprint is composed of RSSI vectors at two points and a displacement vector between them.Random Forests(RF)was used to build regression models to estimate positions from location fingerprints.The root mean square error of position estimation was 0.87 m using 16 Bluetooth beacons.This error is lower than that received with a single-point baseline model,where a feature vector is composed of only RSSI values at one location.The results suggest that the proposed method is effective for indoor positioning.
基金supported by the Hong Kong Polytechnic University (Grant No. G-YH32)
文摘This paper presents the characteristics of the crack growth at the interface of rubber-rubber and rubber-steel bimaterials undertensile deformation using the non-linear finite element method. By using the commercial finite element software ABAQUS,the J integral calculations are carried out for the initial interface crack in the interfaces in-between two Neo-Hookean materials,two Mooney-Rivlin materials, Neo-Hookean and Mooney-Rivlin rubbers, Neo-Hookean and Polynomial, Mooney-Rivlin andPolynomial, and the Mooney-Rivlin and steel bi-materials. The computational results of the maximum J integral directionaround the crack tip illustrate the possible direction of crack growth initiation. Furthermore, it is found that the crack bends tothe softer rubber material at a certain angle with the initial crack direction if the crack depth is relatively small. For the crackwith a larger depth, the crack propagates to grow along the interface in-between the bimaterials.
文摘In this thesis,we establish non-linear wavelet density estimators and studying the asymptotic properties of the estimators with data missing at random when covariates are present.The outstanding advantage of non-linear wavelet method is estimating the unsoothed functions,however,the classical kernel estimation cannot do this work.At the same time,we study the larger sample properties of the ISE for hazard rate estimator.
