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Removing the remaining ridges in fingerprint segmentation
ZHU En, ZHANG Jian-ming, YIN Jian-ping, ZHANG Guo-min, HU Chun-feng
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2006, 7(6 ): 7-.
https://doi.org/10.1631/jzus.2006.A0976
Fingerprint segmentation is an important step in fingerprint recognition and is usually aimed to identify non-ridge regions and unrecoverable low quality ridge regions and exclude them as background so as to reduce the time expenditure of image processing and avoid detecting false features. In high and in low quality ridge regions, often are some remaining ridges which are the afterimages of the previously scanned finger and are expected to be excluded from the foreground. However, existing segmentation methods generally do not take the case into consideration, and often, the remaining ridge regions are falsely classified as foreground by segmentation algorithm with spurious features produced erroneously including unrecoverable regions as foreground. This paper proposes two steps for fingerprint segmentation aimed at removing the remaining ridge region from the foreground. The non-ridge regions and unrecoverable low quality ridge regions are removed as background in the first step, and then the foreground produced by the first step is further analyzed for possible remove of the remaining ridge region. The proposed method proved effective in avoiding detecting false ridges and in improving minutiae detection.
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Protection of mobile location privacy by using blind signature
LIAO Jian, QI Ying-hao, HUANG Pei-wei, RONG Meng-tian, LI Sheng-hong
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2006, 7(6 ): 8-.
https://doi.org/10.1631/jzus.2006.A0984
Location privacy means a user keeps his/her geographical location secret. If location information falls into the wrong hands, an adversary can physically locate a person. To address this privacy issue, Qi et al.(2004a; 2004b) proposed a special and feasible architecture, using blind signature to generate an authorized anonymous ID replacing the real ID of a legitimate mobile user. The original purpose of his architecture was to eliminate the relationship of authorized anonymous ID and real ID. We present an algorithm to break out Qi’s registration and re-confusion protocol, and then propose a new mechanism based on bilinear pairings to protect location privacy. Moreover we show that the administrator or third parity cannot obtain information on the legitimate user’s authorized anonymous ID and real ID in our proposed protocols.
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A wideband frequency-shift keying demodulator for wireless neural stimulation microsystems
DONG Mian, ZHANG Chun, MAI Song-ping, WANG Zhi-hua, LI Dong-mei
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2006, 7(6 ): 19-.
https://doi.org/10.1631/jzus.2006.A1056
This paper presents a wideband frequency-shift keying (FSK) demodulator suitable for a digital data transmission chain of wireless neural stimulation microsystems such as cochlear implants and retinal prostheses. The demodulator circuit derives a constant frequency clock directly from an FSK carrier, and uses this clock to sample the data bits. The circuit occupies 0.03 mm2 using a 0.6 μm, 2M/2P, standard CMOS process, and consumes 0.25 mW at 5 V. This circuit was experimentally tested at transmission speed of up to 2.5 Mbps while receiving a 5~10 MHz FSK carrier signal in a cochlear implant system.
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Projectively flat exponential Finsler metric
YU Yao-yong, YOU Ying
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2006, 7(6 ): 21-.
https://doi.org/10.1631/jzus.2006.A1068
In this paper, we study a class of Finsler metric in the form F=αexp(β/α)+εβ, where α is a Riemannian metric and β is a 1-form, ε is a constant. We call F exponential Finsler metric. We proved that exponential Finsler metric F is locally projectively flat if and only if α is projectively flat and β is parallel with respect to α. Moreover, we proved that the Douglas tensor of exponential Finsler metric F vanishes if and only if β is parallel with respect to α. And from this fact, we get that if exponential Finsler metric F is the Douglas metric, then F is not only a Berwald metric, but also a Landsberg metric.
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25 articles
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