An efficient and robust iris location algorithm plays a very important role in a real iris recognition system. A novel and efficient iris automatic location method is presented in this study. It includes following two...An efficient and robust iris location algorithm plays a very important role in a real iris recognition system. A novel and efficient iris automatic location method is presented in this study. It includes following two steps mainly： pu- pil location and iris outer boundary location. A digital eye image was divided into many small rectangular blocks with fixed size in the pupil location, and the block with the smallest average intensity was selected as a reference area. Then image binarization was implemented taking the average intensity of the reference area as a threshold. At last the center coordinates and radius of pupil were estimated by extending the reference area to the pupil＇s boundaries in the binary iris image. In the iris outer location, two local parts of the eye image were selected and transformed into polar coordinates from Cartesian reference. In order to detect the fainter outer boundary of the iris quickly, a novel edge detector was used to locate boundaries of the two parts. The center coordinates and radius of the iris outer boundary can be estimated using the fusion of the locating results of the two local parts and the location information of the pupil. The algorithm was tested on CASIA vl.0 and MMU vl.0 digital eye image databases and experimental results show that the proposed method has satisfying performance and good robustness.展开更多
The Manchu character recognition method based on Manchu character unit is an efficient method.In this method,the recognition accuracy rate of Manchu character unit has great influence on the final recognition result.A...The Manchu character recognition method based on Manchu character unit is an efficient method.In this method,the recognition accuracy rate of Manchu character unit has great influence on the final recognition result.As new approach to solve this problem,a hybrid wavelet neural network scheme has been developed as an assistant method combine with the original combo-distance method.Due to the properties of the wavelet neural network,the training problem can be transformed into a convex optimization process,therefore the global minimum can be obtained and the learning speed is increases.Both the learning samples set and testing samples set are used,experimental results demonstrate the combine method based on the wavelet neural network is more efficient than the single combo-distance method.展开更多
This paper describes an optical voltage transducer （OVT） for the 35 kV electric power system based on modular interference in dual-mode highly elliptical-core polarization maintenance fiber （E-Core PMF）. The tempe...This paper describes an optical voltage transducer （OVT） for the 35 kV electric power system based on modular interference in dual-mode highly elliptical-core polarization maintenance fiber （E-Core PMF）. The temperature and environmental perturb- bation can be compensated automatically. In the scheme, a quartz crystal cylinder wrapped with highly elliptical-core fiber plays the role of voltage sensor head. The two interference output lobes＇ intensity from the E-core PMF is modulated with the converse piezoelectric effect of quartz crystal. A PZT wrapped with E-core PMF at ground potential serves as the static modular phase difference control and temperature compensation unit. The experiment results indicate that the OVT designed in this paper has satisfying performance and could successfully rejects the temperature perturbation.展开更多
基金Projects 6057201 supported by the National Natural Science Foundation of ChinaLZ985-231-582627 by the 985 Special Study Project of Lanzhou University
文摘An efficient and robust iris location algorithm plays a very important role in a real iris recognition system. A novel and efficient iris automatic location method is presented in this study. It includes following two steps mainly： pu- pil location and iris outer boundary location. A digital eye image was divided into many small rectangular blocks with fixed size in the pupil location, and the block with the smallest average intensity was selected as a reference area. Then image binarization was implemented taking the average intensity of the reference area as a threshold. At last the center coordinates and radius of pupil were estimated by extending the reference area to the pupil＇s boundaries in the binary iris image. In the iris outer location, two local parts of the eye image were selected and transformed into polar coordinates from Cartesian reference. In order to detect the fainter outer boundary of the iris quickly, a novel edge detector was used to locate boundaries of the two parts. The center coordinates and radius of the iris outer boundary can be estimated using the fusion of the locating results of the two local parts and the location information of the pupil. The algorithm was tested on CASIA vl.0 and MMU vl.0 digital eye image databases and experimental results show that the proposed method has satisfying performance and good robustness.
文摘The Manchu character recognition method based on Manchu character unit is an efficient method.In this method,the recognition accuracy rate of Manchu character unit has great influence on the final recognition result.As new approach to solve this problem,a hybrid wavelet neural network scheme has been developed as an assistant method combine with the original combo-distance method.Due to the properties of the wavelet neural network,the training problem can be transformed into a convex optimization process,therefore the global minimum can be obtained and the learning speed is increases.Both the learning samples set and testing samples set are used,experimental results demonstrate the combine method based on the wavelet neural network is more efficient than the single combo-distance method.
基金supported by the National Natural Science Foundation of China under Grant No. 50477001.
文摘This paper describes an optical voltage transducer （OVT） for the 35 kV electric power system based on modular interference in dual-mode highly elliptical-core polarization maintenance fiber （E-Core PMF）. The temperature and environmental perturb- bation can be compensated automatically. In the scheme, a quartz crystal cylinder wrapped with highly elliptical-core fiber plays the role of voltage sensor head. The two interference output lobes＇ intensity from the E-core PMF is modulated with the converse piezoelectric effect of quartz crystal. A PZT wrapped with E-core PMF at ground potential serves as the static modular phase difference control and temperature compensation unit. The experiment results indicate that the OVT designed in this paper has satisfying performance and could successfully rejects the temperature perturbation.
