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Augmented reality registration algorithm based on nature feature recognition

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Science china(Information Sciences) 2010年第8期53卷 1555-1565页

作者： CHEN Jing 1 , WANG YongTian 1,2 , GUO JunWei 1 , LIU Wei 1 , LIN JingDun 1 , XUE Kang 1 , LIU Yue 1 & DING GangYi 31 school of Optoelectronics, beijing institute of technology, beijing 100081, china 2 school of Computer Science and technology, beijing institute of technology, beijing 100081, china 3 school of Software, beijing institute of technology, beijing 100081, china school of Optoelectronics Beijing Institute of Technology Beijing China school of Computer Science and technology Beijing Institute of Technology Beijing China school of Software Beijing Institute of Technology Beijing China

This paper presents an improved key frame based augmented reality registration algorithm for real-time motion tracking in outdoor environment. In such applications, wide-baseline feature matching is a critical problem. In this paper, we apply randomized tree method to match key points extracted from the input image to those key frames as a classification problem. Extended Kalman filter is also utilized for jitter correction. A video see-through mobile augmented reality system is built for the on-site digital reconstruction of Yuanmingyuan Garden. Experimental results demonstrate that this algorithm is real-time, robust and effective for outdoor tracking.

关键词： outdoor augmented reality camera tracking randomized tree

On the stability of diffusion processes with state-dependent switching

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Science china Mathematics 2006年第9期49卷 1258-1274页

作者： XI Fubao & ZHAO Liqin Department of Mathematics, beijing institute of technology, beijing 100081, china school of Mathematical Sciences, beijing Normal University, beijing 100875, china Department of Mathematics Beijing Institute of Technology Beijing China school of Mathematical Sciences Beijing Normal University Beijing China

In this paper we consider the stability for diffusion processes with state-dependent switching. We first prove their Feller continuity by the coupling methods. Furthermore, we also prove their strong Feller continuity and their exponential ergodicity under some reasonable conditions. Finally, we append a very brief discussion about the regularity of these processes.

关键词： Feller continuity, coupling, strong Feller continuity, exponential ergodicity,state-dependent switching.

Visualization of protein RecR in Escherichia coli by fluorescent labelling

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Progress in Natural Science:Materials International 2009年第11期19卷 1545-1551页

作者： Jiefang Qiu,Xuefeng Pan~* school of Life Science,beijing institute of technology,beijing 100081,china school of Life Science Beijing Institute of Technology Beijing 100081 China

RecR protein,a functional equivalent of Rad52 in eukaryotes,plays a critical role in the RecF pathway of homologous recombination in Escherichia *** constructing and expressing the recR-yfp hybrid gene,the distribution of the RecR-YFP fusion protein was visualized in *** by fluorescent *** results showed that RecR proteins can be localized predominantly in the nucleoid region of *** measuring the UV resistance of a recR mutant carrying the recR-yfp gene in the plasmid,the expressed RecR-YFP was found to be functional in improving the UV resistance of the recR deficiency strain.

关键词： RecR YFP DNA Repair Homologous recombination E.coli

The relative generalized Hamming weight and the semilinear equivalence of codes

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Science china(Information Sciences) 2011年第4期54卷 787-794页

作者： LIU ZiHui 1 & WANG Jie 2 1 Department of Mathematics,beijing institute of technology,beijing 100081,china 2 school of Mathematical Sciences,beijing University,beijing 100871,china Department of Mathematics Beijing Institute of Technology Beijing China school of Mathematical Sciences Beijing University Beijing China

Certain equivalent conditions are given for the semilinear equivalence of linear codes by using the relative generalized Hamming weight and the value function.

关键词： value function semilinear equivalence support weight relative generalized Hamming weight

Tuning surface active oxygen of lanthanum oxide via partial dissolution and regrowth of crystallites

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Journal of Natural Gas Chemistry 2011年第5期20卷 483-486页

作者： Zhiming Gao, Huili Li Key Laboratory of Cluster Science, Ministry of Education of china Department of Chemistry, school of Science, beijing institute of technology, beijing 100081, china Key Laboratory of Cluster Science Ministry of Education of China Department of Chemistry School of Science Beijing Institute of Technology Beijing 100081 China

A commercial lanthanum oxide was modified into X%-La2O3 samples via partial dissolution and regrowth of crystallites, wherein the X value denotes the weight percent of the initial metal oxide powder dissolved by nitric acid. BET measurements and TEM observations indicate that the 20%-La2O3 sample has an increased specific surface area, relatively thin and small crystallites in size. TPD/TPR profiles also show that the 20%-La2O3 sample has more surface active oxygen than the 0%-La2O3 sample. Among the four X%-La2O3 samples, the highest activity for methane oxidation was obtained over the 20%-La2O3 sample. Therefore, the present work proves that the method of partial dissolution and regrowth of crystallites are effective to modify surface property of lanthanum oxide.

关键词： solid state reaction surface oxygen crystallite regrowth TPR metal oxide

The mathematical model of wetting angle of heterogeneous nucleation

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Science china(Technological Sciences) 2004年第4期47卷 391-397页

作者： HUANG Cheng1, SONG Bo1, MAO Jinghong2 & ZHAO Pei3 1. school of Metallurgical and Ecological engineering, University of Science and technology beijing, beijing 100083, china 2. school of Material Science, University of Science and technology beijing, beijing 100083, china 3. Central Iron and Steel Research institute, beijing 100081, china school of Metallurgical and Ecological engineering University of Science and Technology Beijing Beijing China school of Material Science University of Science and Technology Beijing Beijing China Central Iron and Steel Research institute Beijing China

The heterogeneous nucleation has been analyzed in terms of the thermodynamic theory, and the mathematical model of wetting angle of heterogeneous nucleation has been developed based on the dynamic requirements of hetero- and homogeneous nucleation. With the wetting angel model, the wetting angles of different catalysts in liquid iron have been calculated. The result shows that the wetting angle of most catalysts is smaller than 40, and the value of f() is far less than 1. The wetting angles of TiN, TiC and RE2O3 are smaller, while the wetting angle of MnO is bigger among the ordinary nucleation catalysts. The wetting angles calculated by this model are in agreement with the results of other research work.

关键词： heterogeneous nucleation, mathematical model, wetting angle, undercooling.

Studies of the unsteady supersonic base flows around three afterbodies

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Acta Mechanica Sinica 2009年第4期25卷 471-479页

作者： Zhixiang Xiao Song Fu school of aerospace engineering,Tsinghua University, 100084 beijing, china school of aerospace engineering Tsinghua University Beijing China

Unsteady supersonic base flows around three afterbodies, cylindrical （Cy）, boattailed （BT） and three-step （MS）, are investigated in this paper. Reynolds-averaged Navier-Stokes （RANS） and two RANS/LES （large-eddy simulation） hybrid methods, detached eddy simulation （DES） and delayed-DES （DDES）, are used to predict the base flow characteristics around the baseline Cy afterbody. All the RANS and hybrid methods are based on the two-equation SST （shear-stress transport） model with compressible corrections （CC）. According to the comparison of measurements, both DES and DDES can produce more satisfactory results than RANS. RANS can only present the ＂stable＂ flow pat- terns, while the hybrid methods can demonstrate unsteady flow structures. DDES and DES results are little different from one another although the latter exhibits better agreement with the experiment. DES is taken to investigate the 5° BT and three-step afterbodies. The mean flow data and the instantaneous turbulent coherent structures are compared against available measurements.

关键词： Cylindrical Boattailed and three-stepafterbodies DES and DDES Unsteady flow

A tracking loop based on tightly coupled range and velocity filter equations

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Science china(Information Sciences) 2012年第4期55卷 898-910页

作者： CUI Wei,TIAN Jing & WU SiLiang school of Information and Electronics,beijing institute of technology,beijing 100081,china school of Information and Electronics Beijing Institute of Technology Beijing China

A joint range-velocity closed tracking loop,which is based on tightly coupled range and velocity filter is *** the measured velocity value is adopted in the range tracking loop to modify the velocity and acceleration equations from traditional α-β-γ filter,the tracking loop based on tightly coupled range and velocity filter can not only track the range and the velocity simultaneously,but also improve the range tracking *** experimental results show that the tracking errors about range thermal noise in the proposed loop is lower than those in the traditional loop over 2.2 dB,when filter parameters satisfy least mean-square error ***,with the increase of the filter parameter,the tracking performance of our schemes are improved accordingly.

关键词： α-β-γ filter tracking loop thermal noise tracking error tightly coupled range and velocity equations

Highly sensitive response to dopamine at a modified electrode involving a composite film with Au nanoparticles dispersed in a fluorocarbon polymer

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Science china Chemistry 2010年第4期53卷 826-831页

作者： KONG LinLin, KAN MeiXiu, HAN DongMei, WANG Ting & ZHANG HuiMin school of Science, beijing institute of technology, beijing 100081, china school of Science Beijing Institute of Technology Beijing China

A new approach for the highly sensitive detection of dopamine by a novel composite film involving gold nanoparticles trapped in a negatively-charged fluorocarbon polymer (Nafion) on a glassy carbon (GC) electrode fabricated by a simple method is described. Gold nanoparticles with an average diameter of 2.3 nm ± 0.2 nm are dispersed throughout the whole Nafion film. The introduction of gold nanoparticles into the Nafion film not only gives a highly active electrode surface area but also increases the conductivity of the Nafion film and the resulting Au/Nafion/GC electrode combines the advantages of the properties of gold nanoparticles and the selective pre-concentration ability of Nafion. For positively charged dopamine, the results show a decrease in the redox peak separation and a high sensitivity. The oxidation peak current of dopamine was shown to vary linearly with dopamine concentration over a wide range from 0.4 to 50.0 μmol/L with a detection limit of 0.3 μmol/L. Negatively charged ascorbic acid shows no redox waves at concentrations up to 1.0 ×10-4 mol/L.

关键词： composite film gold nanoparticles Nafion dopamine ascorbic acid