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One-step estimation for varying coefficient models

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Science China Mathematics 2005年第2期48卷 198-213页

作者： TANG Qingguo & WANG Jinde department of Mathematics, nanjing University, nanjing 210093, China institute of {4., PLA University of Science and Technology, nanjing 210007, China 1. department of Mathematics Nanjing University 210093 Nanjing China 2. institute of sciences PLA University of Science and Technology 210007 Nanjing China

A one-step method is proposed to estimate the unknown functions in the varying coefficient models, in which the unknown functions admit different degrees of smoothness. In this method polynomials of different orders are used to approximate unknown functions with different degrees of smoothness. As only one minimization operation is employed, the required computation burden is much less than that required by the existing two-step estimation method. It is shown that the one-step estimators also achieve the optimal convergence rate. Moreover this property is obtained under conditions milder than that imposed in the two-step estimation method. More importantly, as only one minimization operation is employed, the full asymptotic properties, not only the asymptotic bias and variance, but also the asymptotic distributions of the estimators can be derived. The asymptotic distribution results will play a key role for making statistical inference.

关键词： varying coefficient model, one-step estimation, asymptotic distribution, optimal convergence rate.

A new elliptic-parabolic yield surface model revised by an adaptive criterion for granular soils

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Science China(Technological sciences) 2010年第8期53卷 2152-2159页

作者： LIU HanLong 1,2 ,XIAO Yang 1,2 ,LIU JinYuan 3 &LI GuoYing 4.1 Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering,Hohai University, nanjing 210098,China 2 Geotechnical Research institute,Hohai University,nanjing 210098,China 3department of Civil Engineering,Ryerson University,Toronto,Canada 4.department of Geotechnical Engineering,nanjing Hydraulic Research institute,nanjing 210014.China 1. Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering Hohai University Nanjing 210098 China2. Geotechnical Research Institute Hohai University Nanjing 210098 China3. Department of Civil Engineering Ryerson University Toronto Canada4. Department of Geotechnical Engineering Nanjing Hydraulic Research Institute Nanjing 210014 China

An adaptive criterion for shear yielding as well as shear failure of soils is proposed in this paper to address the fact that most criteria,including the Mohr-Coulomb criterion,the Lade criterion and the Matsuoka-Nakai criterion,cannot agree well with the experimental results when the value of the intermediate principal stress parameter is too *** new criterion can adjust an adaptive parameter based on the experimental results in order to make the theoretical calculations fit the test results more *** original elliptic-parabolic yield surface model can capture both soil contraction and dilation ***,it normally over-predicts the soil strength due to its application of the Extended Mises criterion.A new elliptic-parabolic yield surface mode is presented in this paper,which introduces the adaptive criterion in three-dimensional principal stress *** new model can well model the stress-strain behavior of soils under general stress *** to the original model which can only simulate soil behavior under triaxial compression conditions,the new model can simulate soil behaviors under both triaxial compression conditions and general stress conditions.

关键词： principal stress space intermediate principal stress yield surface failure criterion constitutive model

The onset and advance of the Asian summer monsoon

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Science Bulletin 2006年第1期51卷 80-88页

作者： Lü Junmei1,2,4. ZHANG Qingyun1, TAO Shiyan1 & JU Jianhua3 1. State Key Laboratory of Numerical Modeling for atmospheric Sci- ences and Geophysical Fluid Dynamics, institute of atmospheric Physics, Chinese Academy of sciences, Beijing 100029, China 2. {4. of atmospheric sciences, Yunnan University, Kunming 650091, China 3. China meteorological Administration Training Centre, Beijing 100081, China 4. Graduate School of Chinese Academy of sciences, Beijing 100039, China State Key Laboratory of Numerical Modeling for atmospheric sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China department of atmospheric sciences Yunnan University Kunming 650091 China Graduate School of Chinese Academy of sciences Beijing 100039 China China meteorological Administration Training Centre Beijing 100081 China

Based on the daily outgoing longwave radiation (OLR) data from National Oceanic and At- mospheric Administration (NOAA) satellites, the Cli- mate Prediction Center’s merged analysis of pre- cipitation (CMAP) data and the National Centers for Environmental Prediction/National Center for At- mospheric Research (NCEP/NCAR) reanalysis dataset, the mean intraseasonal variability of the Asian summer monsoon (ASM) is investigated by using power spectrum analysis, band-pass filter, and diagnostic analyses. The processes of the onset and advance of monsoon over the southern part of Indo- china Peninsula, the east coast of Bay of Bengal, the South China Sea and the Indian subcontinent are explored. It is found that there is an abrupt change in OLR, precipitation and zonal wind during the onset and advance of the ASM. It is also indicated that the southern part of Indochina Peninsula and the adja- cent Andaman Sea is the region where the earliest onset of the ASM occurs in the 2nd pentad of May.

关键词： Asian summer monsoon intraseasonal variability onset advance.

Analysis and application of automatic deformation monitoring data for buildings and structures of mining area

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中国有色金属学会会刊：英文版 2011年第S3期21卷 516-522页

作者： XIAO Jie1, 2, 3, ZHANG Jin4.1. institute of Geodesy and Geophysics, Chinese Academy of sciences, Wuhan 4.0077, China 2. Key Laboratory of Dynamic Geodesy, institute of Geodesy and Geophysics, Chinese Academy of sciences, Wuhan 4.0077, China 3. Graduate School of Chinese Academy of sciences, Beijing 10004., China 4. department of Surveying and Mapping, Taiyuan University of Technology, Taiyuan 030024. China Taiyuan Univ Technol Dept Surveying & Mapping Taiyuan 030024 Peoples R China Chinese Acad Sci Inst Geodesy & Geophys Key Lab Dynam Geodesy Wuhan 430077 Peoples R China Chinese Acad Sci Grad Sch Beijing 100049 Peoples R China

The buildings and structures of mines were monitored automatically using modern surveying technology. Through the analysis of the monitoring data, the deformation characteristics were found out from three aspects containing points, lines and regions, which play an important role in understanding the stable state of buildings and structures. The stability and deformation of monitoring points were analysed, and time-series data of monitoring points were denoised with wavelet analysis and Kalman filtering, and exponent function and periodic function were used to get the ideal deformation trend model of monitoring points. Through calculating the monitoring data obtained, analyzing the deformation trend, and cognizing the deformation regularity, it can better service mine safety production and decision-making.

关键词： wavelet analysis Kalman filtering deformation monitoring data analysis mine

Influence of interannual variability of Antarctic oscillation on mei-yu along the Yangtze and Huaihe River valley and its importance to prediction

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Chinese Science Bulletin 2003年第S2期48卷 61-67页

作者： GAO Hui~(1,2), XUE Feng~1 WANG Huijun~1 1. institute of atmospheric Physics, Chinese Academy of sciences, Beijing 100029, China 2. department of atmospheric sciences, nanjing institute of meteorology, nanjing 2.004.. China Chinese Acad Sci Inst Atmospher Phys Beijing 100029 Peoples R China nanjing Inst meteorol Dept Atmospher Sci Nanjing 210044 Peoples R China

Both correlation analysis and case study indi-cate that Antarctic oscillation (AAO) is closely related withsummer rainfall in eastern China. When AAO is stronger inboreal spring, especially in May, there is more mei-yu rain-fall in summer with a longer period along the Yangtze andHuaihe River valley. In contrast, there is less rainfall with ashorter period corresponding to a weaker AAO. Besides, ananomalous AAO changes the position and intensity of severalcirculation systems, which are important to summer rainfallalong the Yangtze and Huaihe River valley. Furthermore, theAntarctic sea ice is negatively correlated with the intensity ofAAO with a 6-month leading time. The result in this studyprovides a new method for the prediction of mei-yu.

关键词： Antarctic oscillation interannual variability mei-yu Antarctic sea ice.

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Progress in Natural Science:Materials International 2005年第12期15卷 1110-1116页

作者： LIU Gang,LI Xin,JIANG Weimei and LI Min department of atmospheric sciences,nanjing University,nanjing 210093,China Beijing Municipal Environmental Protection Bureau,Beijing 10004.,China department of atmospheric sciences Nanjing University Nanjing 210093 China. Beijing Municipal Environmental Protection Bureau Beijing 100044 China

The S-L (She and Leveque) scaling law,also named the hierarchical similarity theory,has been extensively tested for the turbulence made in the laboratory,but seldom been tested for the turbulence in the atmospheric boundary layer (ABL).In this paper, the S-L scaling law is applied to the turbulence in the ABL observed under unstably stratified conditions and over different types of underlying *** results of analyses show that over this type of homogeneous and flat underlying surface,such as the underlying surface in HUBEX (Huaihe River Basin Energy and Water Cycle Experiment),vertical speed and temperature fields well satisfy the S-L scaling *** the turbulence over the homogeneous but rather rough underlying surface of forest and under unstably stratified conditions in PFRD (Park Falls Ranger District of the Chequamegon National Forest,Wisconsin,USA),the analyses show that the vertical speed and temperature fields sometimes conform sometimes do not conform to the S-L scaling ***,at a time,either both of the vertical speed and temperature fields conform to the S-L scaling law,or both of them do *** speed fields in both of the field experiments do not satisfy the S-L scaling *** new explanation of the above-mentioned phenomena is given.

关键词： atmospheric turbulence Reynolds number S-L scaling law in the atmospheric turbulence boundary layer processes nonlinear dynamics

Seasonal variation of global stratosphere-troposphere mass exchange

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Progress in Natural Science:Materials International 2007年第12期17卷 1466-1475页

作者： Guo Dong1,2, Lu Daren2 and Sun Zhaobo1(1. institute of atmospheric sciences, nanjing University of Information Science and Technol{4.,{4., China 2. LAGEO, institute of atmospheric Physics, Chinese Academy of sciences, Beijing 100029, China) institute of atmospheric sciences Nanjing University of Information Science and Technology Nanjing 210044 China LAGEO Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

By Wei formula in pressure coordinate, the stratosphere-troposphere mass exchange (STME) is diagnosed globally for 4. years from 1958 to 2001 using the European Center for Medium-Range Weather Forecasts (ECMWF) reanalysis datasets. Regions of mass flux into the stratosphere are found over Indonesia, bay of Bangladesh and the mid-west coast of South Africa. Compensating mass outflow from the stratosphere appears mainly over mid-latitudes near large-scale troughs. Upward and downward transport of mass at the middle and high latitudes accompany with each other. Mass flux into troposphere is stronger in autumn and winter than in spring and summer. Strong downward mass flux into the troposphere occurs in eastern Asia the whole year with nearly stable sites. Although the area of eastern Asia accounts for only 5.6% of that of the northern hemisphere (NH), its net mass exchange reaches 15.83% of that of the NH, which means that research on STME of eastern Asia is greatly important to that of the NH and even the global areas. Air across the tropopause enters more from stratosphere to troposphere than that from troposphere to stratosphere, which is possibly related with systematic bias of the assimilated datasets and with persistent rise of the tropopause height. Contributions of the mass exchange and the mass flux exchange in the NH and southern hemisphere (SH) on their latitudes increase from equator to pole, with larger contributions in the NH. Mass exchange and mass flux exchange per areas at high latitudes are larger than that at low latitudes, which means greater mass exchange efficiency at high latitudes.

关键词： stratosphere troposphere mass exchange seasonal variation.

THE PHASE RELATION BETWEEN ACCUMULATIVE EFFECT OF SOLAR ECLIPSE AND EL NINO

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南京大学学报(自然科学) 1999年第6期35卷 135-137页

作者： Lin Zhen Shan (department of atmospheric sciences, nanjing University, 210093, nanjing,PRC) 南京大学江苏南京 2 1 0 0 93

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关键词： El Nino eclipse prediction

Random walk modeling of wake dispersion for the exhaust tower of an underground tunnel in urban area

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Journal of Environmental sciences 1999年第4期11卷 474-479页

作者： JIANG Wei\|mei\+1, YU Hong\|bin\+1, LI Xin\+2 (1.department of atmospheric sciences, nanjing University, nanjing 210093, China 2.LAPC, institute of atmospheric Physics,Chinese Academy of sciences, Beijing 100029, China) department of atmospheric sciences Nanjing University Nanjing 210093 China LAPC Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

In this paper, some experimental studies on the impact of effluent from an exhaust tower of an underground tunnel with special construction are reported. By measuring the flow field downstream of the tower in NJU meteorological wind tunnel, some flow characteristics in the make area were established. Based on these, an advanced random\|walk dispersion model was set up and applied successfully to the simulation of dispersion in the wake area. The modelling results were in accordance with wind tunnel measurements. The computed maximum of ground surface concentration in the building case was a factor of 3-4.higher than that in the flat case and appeared much closer to the source. The simulation indicated that random walk modelling is an effective and practical tool for the wake stream impact assessment.

关键词： exhaust tower air pollution in urban area atmospheric dispersion random walk modelling