Zobrazeno 1 - 10
of 35
pro vyhledávání: '"Nianfeng Liu"'
Publikováno v:
IET Biometrics, Vol 11, Iss 5, Pp 420-429 (2022)
Abstract Iris presentation attack detection (PAD) is still an unsolved problem mainly due to the various spoof attack strategies and poor generalisation on unseen attackers. In this paper, the merits of both light field (LF) imaging and deep learning
Externí odkaz:
https://doaj.org/article/93f202ce2eb1434d9e7b9e7015d52e18
Publikováno v:
PLoS ONE, Vol 10, Iss 8, p e0135572 (2015)
Urbanization is proceeding rapidly in several developing countries such as China. This accelerating urbanization alters the existing land use types in a way that results in more Non-Point Source (NPS) pollution to local surface waters. Reasonable lan
Externí odkaz:
https://doaj.org/article/93e6b992c65645399f9a8f24f9852477
Publikováno v:
2019 International Conference on Optical Instruments and Technology: Optical Communication and Optical Signal Processing.
NIM has built three cesium fountain clocks in Beijing area. NIM5 fountain clock has been reported to BIPM since 2014. The microwave synthesizer and computer control system of NIM5 had been modified recently. The type-B uncertainty is 9×10−16, limi
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::fd2eeb8b8882aff98302955c5b99f5bd
https://doi.org/10.1117/12.2555108
https://doi.org/10.1117/12.2555108
Publikováno v:
IEEE Transactions on Information Forensics and Security. 12:2373-2386
Matching heterogeneous iris images in less constrained applications of iris biometrics is becoming a challenging task. The existing solutions try to reduce the difference between heterogeneous iris images in pixel intensities or filtered features. In
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::658fe7d34fa0a0fca5d05372607a3ec9
https://doi.org/10.1109/tifs.2017.2686013
https://doi.org/10.1109/tifs.2017.2686013
Autor:
Tianchu Li, Shaoyang Dai, Lei Han, Nianfeng Liu, Kun Liu, Weiliang Chen, Fasong Zheng, Fang Fang
Publikováno v:
2019 Joint Conference of the IEEE International Frequency Control Symposium and European Frequency and Time Forum (EFTF/IFC).
Two Cs fountains clocks have been built in NIM. NIM5 fountain clock has been reported to BIPM since 2014. The microwave synthesizer and computer control system of NIM5 had been modified recently. The Type-B uncertainty is 9×10-16, limited by the int
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::ccfe22be5f66d9c886a46b4950980a8d
https://doi.org/10.1109/fcs.2019.8856067
https://doi.org/10.1109/fcs.2019.8856067
Publikováno v:
2019 URSI Asia-Pacific Radio Science Conference (AP-RASC).
The optical generation of microwave (OGM) based on ultra-stable laser (USL) and fiber optical frequency comb (OFC) is built at the National Institute of Metrology (NIM), China. As shown in Fig1, the OFC is stabilized with USL by controlling the pumpi
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::ae82a0ad435e32e5365e29475adf175c
https://doi.org/10.23919/ursiap-rasc.2019.8738383
https://doi.org/10.23919/ursiap-rasc.2019.8738383
Publikováno v:
2019 URSI Asia-Pacific Radio Science Conference (AP-RASC).
In this paper, we introduce the design of our new fountain clock NIM6. Besides some improvements on the vacuum system, Ramsey cavity to reduce the Type B uncertainty, NIM6 collects atoms from a MOT loading optical molasses to get a better signal to n
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::9674fc5bc459d20a9a124484c60f5b47
https://doi.org/10.23919/ursiap-rasc.2019.8738417
https://doi.org/10.23919/ursiap-rasc.2019.8738417
Publikováno v:
Measurement Science and Technology. 32:055008
Network time service provided by Network Time Protocol (NTP) servers is widely used to synchronize the clocks of computers and other networked equipment. With the rapid development of smart devices and their applications, more NTP servers as time sou
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::caaec095cb8028f18be6cad9b858a6a2
https://doi.org/10.1088/1361-6501/abd799
https://doi.org/10.1088/1361-6501/abd799
Publikováno v:
Pattern Recognition Letters. 82:154-161
Heterogeneous iris recognition (HIR) is in great demand for a large-scale identity management system. Iris images acquired in heterogeneous environment have large intra-class variations, such as different resolutions or different sensor optics, etc.
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::9fa939dc689c30ab0a17f5e1aff32ed3
https://doi.org/10.1016/j.patrec.2015.09.016
https://doi.org/10.1016/j.patrec.2015.09.016
Publikováno v:
AIP Advances, Vol 10, Iss 6, Pp 065118-065118-5 (2020)
We present an oscillator of optically generated microwaves (OGMs) based on an optical frequency comb (OFC) and an ultrastable laser (USL). The USL provides short-term stability, and the OFC transfers the short-term stability to radio frequencies. Fre
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::5b5979a4df024b1d42a1e6a4e5a09175
https://doi.org/10.1063/5.0003839
https://doi.org/10.1063/5.0003839