In modern electromagnetic environment, radar emitter signal recognition is an important research topic. On the basis of multi-resolution wavelet analysis, an adaptive radar emitter signal recognition method based on m...In modern electromagnetic environment, radar emitter signal recognition is an important research topic. On the basis of multi-resolution wavelet analysis, an adaptive radar emitter signal recognition method based on multi-scale wavelet entropy feature extraction and feature weighting was proposed. With the only priori knowledge of signal to noise ratio(SNR), the method of extracting multi-scale wavelet entropy features of wavelet coefficients from different received signals were combined with calculating uneven weight factor and stability weight factor of the extracted multi-dimensional characteristics. Radar emitter signals of different modulation types and different parameters modulated were recognized through feature weighting and feature fusion. Theoretical analysis and simulation results show that the presented algorithm has a high recognition rate. Additionally, when the SNR is greater than-4 d B, the correct recognition rate is higher than 93%. Hence, the proposed algorithm has great application value.展开更多
The method extracting the electromagnetic parameters from scattering coefficients was studied in this paper. The Support Vector Machine (SVM) method is used to solve the inverse problem of parameters extraction. The m...The method extracting the electromagnetic parameters from scattering coefficients was studied in this paper. The Support Vector Machine (SVM) method is used to solve the inverse problem of parameters extraction. The mapping relationship is set up by calculating a large number of S pa-rameters from the samples with different permittivity by using transmission line theory. The simulated data set is used as training data set for SVM. After the training, the SVM is used to predict the permittivity of material from the scattering coefficients.展开更多
TiO2 thin films deposited by magnetron sputtering possess excellent optical transmittance,high refractive index,good adhesion and chemical stability.In this manuscript,TiO2 thin films deposited by magnetron sputtering...TiO2 thin films deposited by magnetron sputtering possess excellent optical transmittance,high refractive index,good adhesion and chemical stability.In this manuscript,TiO2 thin films deposited by magnetron sputtering was used for the first time as an electron extraction layer in inverted polymer solar cells(IPSCs),and the effect of the TiO2 thickness on the photovoltaic performance of P3HT:PC61BM IPSCs was investigated.The highest PCE value of 3.75%was obtained when the thickness of TiO2thin films was in the range between 42 nm and 73 nm.The absorption properties,morphology and structure of the TiO2 films were characterized by UV-Vis spectroscopy,SEM and Raman spectroscopy,and were related to the device performance of P3HT:PC61BM IPSCs.The results indicate that TiO2 films deposited by magnetron sputtering are an excellent electron extraction layer for IPSCs.展开更多
基金Project(61301095)supported by the National Natural Science Foundation of ChinaProject(QC2012C070)supported by Heilongjiang Provincial Natural Science Foundation for the Youth,ChinaProjects(HEUCF130807,HEUCFZ1129)supported by the Fundamental Research Funds for the Central Universities of China
文摘In modern electromagnetic environment, radar emitter signal recognition is an important research topic. On the basis of multi-resolution wavelet analysis, an adaptive radar emitter signal recognition method based on multi-scale wavelet entropy feature extraction and feature weighting was proposed. With the only priori knowledge of signal to noise ratio(SNR), the method of extracting multi-scale wavelet entropy features of wavelet coefficients from different received signals were combined with calculating uneven weight factor and stability weight factor of the extracted multi-dimensional characteristics. Radar emitter signals of different modulation types and different parameters modulated were recognized through feature weighting and feature fusion. Theoretical analysis and simulation results show that the presented algorithm has a high recognition rate. Additionally, when the SNR is greater than-4 d B, the correct recognition rate is higher than 93%. Hence, the proposed algorithm has great application value.
基金Supported by the Project of National Key Laboratory Fund
文摘The method extracting the electromagnetic parameters from scattering coefficients was studied in this paper. The Support Vector Machine (SVM) method is used to solve the inverse problem of parameters extraction. The mapping relationship is set up by calculating a large number of S pa-rameters from the samples with different permittivity by using transmission line theory. The simulated data set is used as training data set for SVM. After the training, the SVM is used to predict the permittivity of material from the scattering coefficients.
基金financially supported the National Natural Science Foundation of China (20904057 21074055)+3 种基金the Open Fund of Key Laboratory of Advanced Functional Polymeric Materials of College of Hunan Province (12K049)Beijing Natural Science Foundation (2122050)Basic Research Foundation of the Central Universities (2013JBZ004)J. Zhang acknowledges support by the "100 Talents Program" of the Chinese Academy of Sciences
文摘TiO2 thin films deposited by magnetron sputtering possess excellent optical transmittance,high refractive index,good adhesion and chemical stability.In this manuscript,TiO2 thin films deposited by magnetron sputtering was used for the first time as an electron extraction layer in inverted polymer solar cells(IPSCs),and the effect of the TiO2 thickness on the photovoltaic performance of P3HT:PC61BM IPSCs was investigated.The highest PCE value of 3.75%was obtained when the thickness of TiO2thin films was in the range between 42 nm and 73 nm.The absorption properties,morphology and structure of the TiO2 films were characterized by UV-Vis spectroscopy,SEM and Raman spectroscopy,and were related to the device performance of P3HT:PC61BM IPSCs.The results indicate that TiO2 films deposited by magnetron sputtering are an excellent electron extraction layer for IPSCs.
