Huo G.,Jilin University |
Huo G.,Northeast Dianli University |
Liu Y.,Jilin University |
Zhu X.,Jilin University |
And 5 more authors.
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2014
The parameter selection of SIFT operator is the premise and difficulty of feature extraction with SIFT. Based on a analysis of the change regulation between each parameter of SIFT operator and the valid key points in detail, a variety of parameter selection ways to fit to extract iris texture features are put forward in this paper. A new set of feature matching method is designed and realized according to the features. According to the experimental results from three public iris databases, including CASIA V1.0, CASIA-V3-Interval and MMU, compared with classical SIFT method of Lowe, the method we proposed has been proven to increase by 2% to 5% in recognition accuracy. It shows that the method we proposed has strong robustness and high recognition ability. © Springer International Publishing Switzerland 2014.
Feng C.,Shijiazhuang Vocational College for Scientific and Technical Engineering |
Meng Y.,Hebei University of Engineering |
Liu X.,Shijiazhuang Vocational College for Scientific and Technical Engineering |
Wang J.,Shijiazhuang Vocational College for Scientific and Technical Engineering |
Yang L.,Shijiazhuang Vocational College for Scientific and Technical Engineering
Xiyou Jinshu/Chinese Journal of Rare Metals | Year: 2013
Ca3Sc2Si3O12, green-emitting phosphors for white LED were firstly synthesized by microwave field. The crystal structure, morphology and luminescence properties of as-synthesized Ca3Sc2Si3O12:Ce were investigated by X-ray diffraction, SEM and fluorescence spectrophotometer respectively. The results showed that the crystal structure of as-synthesized Ca3Sc2Si3O12:Ce was cubic with space groups of Ia3d, which was similar to that of Ca3Sc2Si3O12. The particles of as-synthesized phosphor were basically spherical shape, and dispersing well. The particle size was smaller than 1 μm. The excitation spectrum showed that a broad absorption located at 400~500 nm, suggesting it was very suitable for a color converter in white light-emitting diode (LED). The emission spectrum also showed a broad emission, and the main emission peak located at 505 nm. Bright green-emission broad was attributed to the characteristic emissions 5d-2F5/2 and 5d-2F7/2 transitions of Ce3+. It was also found that the molar ratio of Tb3+ played a very important role in the emission spectrum. The optimal doping concentration of Ce in Ca3-xSc2 Si3O12:Cex was x=0.10. Further increasing the molar ratio of Ce, the green emitting becomes weak.
Zhang H.-J.,CAS National Astronomical Observatories |
Zhang H.-J.,University of Chinese Academy of Sciences |
Zhou J.-J.,CAS National Astronomical Observatories |
Dong G.-L.,Shijiazhuang Vocational College for Scientific and Technical Engineering |
And 4 more authors.
Astrophysics and Space Science | Year: 2010
We collected infrared and radio data on 110 OH/IR stars, 65 S stars and 184 C-rich stars from the literature. We analyzed their spectral energy distributions, bolometric magnitudes, infrared colors and mass-loss rates. Our study confirms that OH/IR stars and C-rich stars reach similarly high mass-loss rates at similar luminosities, supporting the idea that mass-loss rates are determined by internal stellar activities such as pulsation rather than the properties of their envelopes. The mass-loss rates of OH/IR stars and C-rich stars are strongly correlated with the color indices K-[A], K-[C], K-[D] and K-[E], and the two populations can be described with one formula. Our study also reveals that only those stars with color indices K-[A]<4 or K-[C]<5 have SEDs that peak in the near-infrared waveband. © 2010 Springer Science+Business Media B.V.
Xie Q.R.,Shijiazhuang vocational college for scientific and technical engineering
Applied Mechanics and Materials | Year: 2014
The thesis is based on the university network management work in combine with the characters and requirements of the school. A service- oriented architecture is adopted to integrate multi-business systems across different platforms. The unified authentication, single sign-on, data exchange and share are implemented. It improves the school normalization level, broadens society service fields of the vocational colleges at the same time avoids the rebuilding in the normalization work and saves the investment. A reliable information base is supplied for the next stage virtual campus construction. © (2014) Trans Tech Publications, Switzerland.