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ON THE SYMPLECTIC REDUCTIONS

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Chinese Annals of Mathematics,Series B 2002年第3期23卷 425-434页

作者： HE LONGGUANG ZHONG DESHOU LIU BAOKANG: Department of Mathematics, capital normal university, beijing 100037, china. Department of Mathematics Capital Normal University Beijing 100037 China

A symplectic reduction method for symplectic G-spaces is given in this paper without using the existence of momentum mappings. By a method similar to the above one, the arthors give a symplectic reduction method for the Poisson action of Poisson Lie groups on symplectic manifolds, also without using the existence of momentum mappings. The symplectic reduction method for momentum mappings is thus a special case of the above results.

关键词： Symplectic reduction Symplectic action Poisson action Momentum mapping Stable subgroup

Scenario simulation and forecast of land use/cover in northern china

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Chinese science Bulletin 2008年第9期53卷 1401-1412页

作者： LI YueChen 1,2,3 & HE ChunYang 3 1 college of Geographical science, Chongqing normal university, Chongqing 400047, china 2 college of Resources and Environmental science, Chongqing university, Chongqing 400044, china 3 college of Resources science & Technology, beijing normal university, beijing 100875, china college of Geographical science Chongqing Normal University Chongqing 400047 China college of Resources and Environmental science Chongqing University Chongqing 400044 China college of Resources science & Technology Beijing Normal University Beijing 100875 China

Modeling land use/cover scenario changes and its potential impacts on structure and functions of ecosystem in typical regions are helpful to understanding the interactive mechanism between land use/cover system and ecosystem. Based on the analysis of the existing land use/cover simulation and forecast models, a land use/cover scenario dynamics model by the integration of System Dynamics (SD) model, Back Propagation Neural Network (BPNN) and Cellular Automata (CA) model is developed with land use/cover scenario changes in northern china in the next 30 years and simulated in this paper. The model is to simulate the land use/cover scenario demands by using a SD model at first, and then allocating the land use scenario patterns at the local scale with the considerations of land use/cover suitability, inheritance ability and neighborhood effect by using BPNN-CA model to satisfy the balance between land use/cover scenario demands and supplies. It integrates the advantages of SD, BPNN and CA. Macro-driving factors and the micro-spatial pattern are also fully taken into account. The BPNN simplifies the identification of the factors’ weights used in CA model and improves the reliability of the simulation results. The simulation accuracy of the model developed in this paper was found to be about 74%. It suggests that the model has the ability to reflect the complexity of land use/cover system at different scales to some extent and it is a useful tool for assessing the potential impacts of land use system on ecosystem. The simulated results also indicate that the urban land, water area and forest will increase significantly, and farmland and unable land will decrease gradually. Obvious land use/cover changes will take place in the farming-pastoral zone and the southeast area of northern china.

关键词：土地利用中国北方细胞自动机系统动力学

BPF-based reconstruction algorithm for multiple rotation-translation scan mode

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Progress in Natural science:Materials International 2008年第2期18卷 209-216页

作者： Ming Chen,Huitao Zhang,Peng Zhang Computer Tomography Laboratory,capital normal university,beijing 100037,china Computer Tomography Laboratory Capital Normal University Beijing 100037 China

In industrial CT,it is often required to inspect large objects using short line-detectors. To acquire the complete CT data for the scan-ning slice of large objects using short line-detectors,some multi-scan modes have been developed. But the existing methods reconstruct-ing an image from the data scanned by multi-scan modes have to rebin the data into fan-beam or parallel-beam form via data interpolation. The data rebinning process not only increases great computational cost,but also degrades image resolution. In this paper,we propose a backprojection-filtration (BPF)-based reconstruction algorithm for rotation-translation (RT) multi-scan mode. An impor-tant feature of the proposed algorithm is that data rebinning process is not introduced. The simulation results have verified the validity of the proposed algorithm.

关键词： Backprojection-filtration Reconstruction algorithm Multiple rotation-translation scan mode Fan-beam

Average Widths of Sobolev-Wiener Classes with Mixed Smoothness in L_q(R^d)

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Acta Mathematica Sinica,English Series 2001年第2期17卷 305-312页

作者： He Ping WANG Department of Mathematics, capital normal university. beijing, 100037, P. R. china Department of Mathematics Capital Normal University Beijing 100037 P. R. China

In this paper, the average σ-K width of Sobolev-Wiener classes Spqr W with mixed smooth- ness in Lq（Rd） is studied for 1

关键词： Sobolev-Wiener classes with mixed smoothness Average σ-K width Step hyperbolic crosses

New dragonflies (Insecta: Odonata: Gomphaeschnidae) from the Yixian Formation in Inner Mongolia, china

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Progress in Natural science:Materials International 2008年第1期18卷 59-64页

作者： Binglan Zhang a ,Dong Rena ,*,Hong Pang b acollege of life science,capital normal university,beijing 100037,china bState Key Laboratory of Biocontrol and Institute of Entomology,Sun Yat-sen university,Guangzhou 510275,china college of life science Capital Normal University Beijing 100037 China State Key Laboratory of Biocontrol and Institute of Entomology Sun Yat-sen University Guangzhou 510275 China

Two fossil dragonflies from the Upper Jurassic to Lower Cretaceous Yixian Formation in Liutiaogou Village,Ningcheng County, Inner Mongolia,china are described and *** are assigned to two new genera and species,i.e.,Sophoaeschna frigida gen. et *** Falsisophoaeschna generalis *** *** the family Gomphaeschnidae Tillyard&Fraser,*** is the first report of Odonata from Yixian Formation in Inner Mongolia and the second record of fossil Gomphaeschnidae from china.

关键词： Odonata New genus Upper Jurassic to Lower Cretaceous Yixian Formation china

A Besov Estimate for Multilinear Singular Integrals

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Acta Mathematica Sinica,English Series 2000年第4期16卷 613-626页

作者： Wengu Chen Department of Mathematics, capital normal university. beijing 100037. P. R. china Department of Mathematics Capital Normal University Beijing 100037 P. R. China

The main pnrpose of this paper is to prove a good λ inequality for a multilinear singular integral in R^n.

关键词： Multilinear operator Besov space Good λ inequality

On multi-scale representations of geographic features

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science china(Technological sciences) 2006年第z2期49卷 39-47页

作者： WANG Yanhui, LI Xiaojuan & GONG Huili Key Laboratory of 3D Information Acquisition and Application, MOE, capital normal university, beijing 100037, china Key Lab Laboratory of Resource Environment and GIS of beijing, capital normal university, beijing 100037, china capital normal Univ MOE Key Lab D Informat Acquisit & Applicat 3 Beijing 100037 Peoples R China capital normal Univ Key Lab Lab Resource Environm Beijing 100037 Peoples R China capital normal Univ GIS Beijing Beijing 100037 Peoples R China

This paper contains a review of the development of research on multiple representations compiled from Geographic Information Systems (GIS), including data structure, formalization and storage, and intelligent zoom. A summary is also included of the problems of interconnectivity, consistency maintenance, dynamic query and coexisting updates, as well as a research review of multi-scale databases and related studies. Finally,research directions and foci are proposed for the future design and implementation of multi-scale GIS.

关键词： multi-scale representation, multi-scale database, interconnectivity, consistency maintenance.

Development and application of ergodicity model with FRCM and FLAR for hydrological process

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science china(Technological sciences) 2009年第2期52卷 379-386页

作者： WANG HongRui1, FENG QiLei2, LIN Xin3 & ZENG WenYi4 1 college of Water science, Key Laboratory for Water and Sediment sciences of the Ministry of Education, beijing normal university, beijing 100875, china 2 School of science, beijing Institute of Education, beijing 100011, china 3 School of Mathematical sciences, beijing normal university, beijing 100875, china 4 college of Information science and Technology, beijing normal university, beijing 100875, china 1. college of Water science Key Laboratory for Water and Sediment Sciences of the Ministry of Education Beijing Normal University Beijing 100875 China 2. School of science Beijing Institute of Education Beijing 100011 China 3. School of Mathematical sciences Beijing Normal University Beijing 100875 China 4. college of Information science and Technology Beijing Normal University Beijing 100875 China

In this paper, a new ergodic property analysis model of hydrological process is proposed based on fuzzy-rough c-means clustering (FRCM), autocorrelogram, and fuzzy least absolute regression (FLAR). A precipitation time series (1951―2004) from Shanghai Hydrology Station is then analyzed with the model. The results show that the precipitation time series of April, May, June, and September has er-godic property. We conclude that in the long run, the precipitation of April, May, June, and September will not keep decreasing; it will converge to its mean value in some period.

关键词： hydrological process ergodic autocorrelogram fuzzy-rough c-means clustering fuzzy least absolute regression

Existence and Multiplicity of Periodic Solutions of the Second-Order Differential Equations with Jumping Nonlinearities

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Acta Mathematica Sinica,English Series 2002年第3期18卷 615-624页

作者： Zai Hong WANG Department of Mathematics, capital normal university. beijing 100037. P. R. china Department of Mathematics Capital Normal University Beijing P. R. China

We provide sufficient conditions for the existence and multiplicity of periodic solutions for Duffing's equations with jumping nonlinearities under resonance conditions.

关键词： Periodic solution Jumping nonlinearities Spectrum curve Time map