Vertical raindrop size distributions of two stratiform rain events were measured with a Micro Rain Radar during summer 2009 at a semiarid continental site located in Xilinhot, China (43°38′N, 116°42′E). ...Vertical raindrop size distributions of two stratiform rain events were measured with a Micro Rain Radar during summer 2009 at a semiarid continental site located in Xilinhot, China (43°38′N, 116°42′E). The sequential intensity filtering technique (SIFT) was used to minimize the effect of the spurious variability on disdrometric data to obtain the reflectivity-rain rate (Z-R) relationship (Z = αRb). Compared with the least squares regression (LSR) method, SIFT led to a -5% to 4% change in the coefficient (a) and an 8%-1 5% increase in the exponent (b) of the Z-R relationship at 300 m. Rainfall estimation using the Z-R relationship with SIFT had lower standard deviation than that with LSR. The vertical variability of the mean rain rate, total raindrop numbers, and parameters (a and b) of the Z-R relationship was small below a melting layer, suggesting that using the radar reflectivity of weather radar to estimate stratiform rainfall is relatively accurate, at least in the Xilinhot area.展开更多
To promote the modeling standardization process of the integrated circuits, an improved electrical simulation model for a direct power injection (DPI) setup which was used to measure the conducted immunity of a 16-b...To promote the modeling standardization process of the integrated circuits, an improved electrical simulation model for a direct power injection (DPI) setup which was used to measure the conducted immunity of a 16-bit microcontroller to radio frequency aggression was investigated. Based on the existing model of the same microcontroller, the PDN module was modified by adding the core, PLL and MD network models, which could reflect the actual electric distribution situation within the microcontroller more accurately. By comparing the simulation results with the measurement results, the effectiveness of the modified model can be improved to 500 MHz, and its uncertainty is within +1.8 dB (+2 dB is acceptable). Then, to improve the simulation accuracy of the complete model in the high frequency range, the I/O model which contained the dynamic and nonlinear characteristics reflecting the variation of the internal impedance of the microcontroller with increasing the frequency of the external noise was introduced. By comparing the simulation results with the measurement results, the effectiveness of the second modified model can be improved up to 1.4 GHz with the uncertainty of ~1.8 dB. Thus, a conclusion can be reached that the proposed model can be applied to a much wider frequency range with a smaller uncertainty than the latest model of the similar type. Furthermore, associated with the electromagnetic emission testing platform model, the PDN module can also be used to predict the electromagnetic conducted and radiated emission characteristics. This modeling method can also be applied to other integrated circuits, which is very helpful to the standardization of the IC electromagnetic compatibility (EMC) modeling process.展开更多
The study considers the morphological and physiological behaviour of self-rooted sweet cherry CV (Cultivar) 'Hedelfinger' wild type (H) and somaclonal (HS) grafted on 'Gisela 6' and 'Colt' rootstock. The s...The study considers the morphological and physiological behaviour of self-rooted sweet cherry CV (Cultivar) 'Hedelfinger' wild type (H) and somaclonal (HS) grafted on 'Gisela 6' and 'Colt' rootstock. The somaclonal showed reduced vegetative vigour without any variation of the natural tree's architecture. The rootstock 'Gisela 6' caused change in genotype habitus inducing a spreading shape, while 'Colt' increased trunk diameter and height. Fruit quality and size were not affected by genotype nor rootstock. 'Gisela 6', from these preliminary data, had proved the most suitable rootstock for both genotypes since it reduced the tree size and vigor and induced early bearing and the production of a greater number of fruiting spurs.展开更多
Using Time-Varying AR (TVAR) model and adaptive notch filter is a new method for the non-stationary jammer suppression in Direct Sequence Spread Spectrum (DSSS). The performance of TVAR model for Instantaneous Frequen...Using Time-Varying AR (TVAR) model and adaptive notch filter is a new method for the non-stationary jammer suppression in Direct Sequence Spread Spectrum (DSSS). The performance of TVAR model for Instantaneous Frequency (IF) estimation will be affected by some factors such as basis functions. Focusing on this problem, the optimal basis function of TVAR model for the IF estimation of the LFM signal is obtained in this paper. Besides the depth and width of notching, the phase properties of notch filter affect the Signal-to-Interference plus-Noise Ratio (SINR) of correlation output to the narrowband jammer suppression in DSSS, in response to the problem the closed solution of correlation output SINR improvement has been derived when a single frequency jammer passes through direct IIR notch filter, and its performance has been compared with those of five coefficient FIR filters. Later, a novel method for LFM jammer suppression based on Fourier basis TVAR model and direct IIR notch filter is proposed. The simulation results show the effectiveness of the proposed method.展开更多
基金partially supported by the German Research Foundation[Research Unit 536,MAGIM]National Natural Science Foundation of China[grant number 41175105],[grant number41175122],[grant number 41505091],[grant number 41575124]
文摘Vertical raindrop size distributions of two stratiform rain events were measured with a Micro Rain Radar during summer 2009 at a semiarid continental site located in Xilinhot, China (43°38′N, 116°42′E). The sequential intensity filtering technique (SIFT) was used to minimize the effect of the spurious variability on disdrometric data to obtain the reflectivity-rain rate (Z-R) relationship (Z = αRb). Compared with the least squares regression (LSR) method, SIFT led to a -5% to 4% change in the coefficient (a) and an 8%-1 5% increase in the exponent (b) of the Z-R relationship at 300 m. Rainfall estimation using the Z-R relationship with SIFT had lower standard deviation than that with LSR. The vertical variability of the mean rain rate, total raindrop numbers, and parameters (a and b) of the Z-R relationship was small below a melting layer, suggesting that using the radar reflectivity of weather radar to estimate stratiform rainfall is relatively accurate, at least in the Xilinhot area.
基金Project(2007dfa71250) supported by the International Science and Technology Cooperative Program of ChinaProject(20062250) supported by the Doctor Fund of North China Electric Power University, China
文摘To promote the modeling standardization process of the integrated circuits, an improved electrical simulation model for a direct power injection (DPI) setup which was used to measure the conducted immunity of a 16-bit microcontroller to radio frequency aggression was investigated. Based on the existing model of the same microcontroller, the PDN module was modified by adding the core, PLL and MD network models, which could reflect the actual electric distribution situation within the microcontroller more accurately. By comparing the simulation results with the measurement results, the effectiveness of the modified model can be improved to 500 MHz, and its uncertainty is within +1.8 dB (+2 dB is acceptable). Then, to improve the simulation accuracy of the complete model in the high frequency range, the I/O model which contained the dynamic and nonlinear characteristics reflecting the variation of the internal impedance of the microcontroller with increasing the frequency of the external noise was introduced. By comparing the simulation results with the measurement results, the effectiveness of the second modified model can be improved up to 1.4 GHz with the uncertainty of ~1.8 dB. Thus, a conclusion can be reached that the proposed model can be applied to a much wider frequency range with a smaller uncertainty than the latest model of the similar type. Furthermore, associated with the electromagnetic emission testing platform model, the PDN module can also be used to predict the electromagnetic conducted and radiated emission characteristics. This modeling method can also be applied to other integrated circuits, which is very helpful to the standardization of the IC electromagnetic compatibility (EMC) modeling process.
文摘The study considers the morphological and physiological behaviour of self-rooted sweet cherry CV (Cultivar) 'Hedelfinger' wild type (H) and somaclonal (HS) grafted on 'Gisela 6' and 'Colt' rootstock. The somaclonal showed reduced vegetative vigour without any variation of the natural tree's architecture. The rootstock 'Gisela 6' caused change in genotype habitus inducing a spreading shape, while 'Colt' increased trunk diameter and height. Fruit quality and size were not affected by genotype nor rootstock. 'Gisela 6', from these preliminary data, had proved the most suitable rootstock for both genotypes since it reduced the tree size and vigor and induced early bearing and the production of a greater number of fruiting spurs.
基金Supported by the Natural Science Foundation of Hebei Province (F2010000442)
文摘Using Time-Varying AR (TVAR) model and adaptive notch filter is a new method for the non-stationary jammer suppression in Direct Sequence Spread Spectrum (DSSS). The performance of TVAR model for Instantaneous Frequency (IF) estimation will be affected by some factors such as basis functions. Focusing on this problem, the optimal basis function of TVAR model for the IF estimation of the LFM signal is obtained in this paper. Besides the depth and width of notching, the phase properties of notch filter affect the Signal-to-Interference plus-Noise Ratio (SINR) of correlation output to the narrowband jammer suppression in DSSS, in response to the problem the closed solution of correlation output SINR improvement has been derived when a single frequency jammer passes through direct IIR notch filter, and its performance has been compared with those of five coefficient FIR filters. Later, a novel method for LFM jammer suppression based on Fourier basis TVAR model and direct IIR notch filter is proposed. The simulation results show the effectiveness of the proposed method.