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A LAW OF ITERATED LOGARITHM FOR THE MLE IN A RANDOM CENSORING MODEL WITH INCOMPLETE information

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Acta Mathematica Scientia 2008年第3期28卷 501-512页

作者：宋凤丽刘禄勤 school of mathematics and Statistics Wuhan University

In this article, a law of iterated logarithm for the maximum likelihood estimator in a random censoring model with incomplete information under certain regular conditions is obtained.

关键词： Random censoring model maximum likelihood estimator law of iterated logarithm

A three-dimensional variational ocean data assimilation system:Scheme and preliminary results

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science china Earth sciences 2006年第11期49卷 1212-1222页

作者： ZHU Jiang1,2, ZHOU Guangqing1, YAN Changxiang1, FU Weiwei1 & YOU Xiaobao1,3 1. International Center for Climate and Environment sciences, Institute of Atmospheric physics, Chinese Academy of sciences, Beijing 100029, china 2. Jiangsu Key Laboratory of Meteorological Disaster, nanjing university of information science and technology, nanjing 210044, china 3. Beijing Institute of Applied Meteorology, Beijing 100029, china International Center for Climate and Environment sciences Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China Jiangsu Key Laboratory of Meteorological Disaster Nanjing University of Information Science and Technology Nanjing China Beijing Institute of Applied Meteorology Beijing China

A new 3DVAR-based Ocean Variational Analysis System (OVALS) is developed. OVALS is capable of assimilating in situ sea water temperature and salinity observations and satellite altimetry data. As a component of OVALS, a new variational scheme is proposed to assimilate the sea surface height data. This scheme considers both the vertical correlation of background errors and the nonlinear temperature-salinity relationship which is derived from the generalization of the linear balance constraints to the nonlinear in the 3DVAR. By this scheme, the model temperature and salinity fields are directly adjusted from the altimetry data. Additionally, OVALS can assimilate the temperature and salinity profiles from the ARGO floats which have been implemented in recent years and some temperature and salinity data such as from expendable bathythermograph, moored ocean buoys, etc. A 21-year assimilation experiment is carried out by using OVALS and the Tropical Pacific circulation model. The results show that the assimilation system may effectively improve the estimations of temperature and salinity by assimilating all kinds of observations. Moreover, the root mean square errors of temperature and salinity in the upper depth less than 420 m reach 0.63℃ and 0.34 psu.

关键词： data assimilation, 3DVAR, sea surface height, ARGO floats.

MMSE relay precoding schemes based on quantization error compensation for multi-relay system

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science china(information sciences) 2010年第12期53卷 2548-2556页

作者： LI Ting 1,2 & YANG LuXi 2 1 College of Communication and information Engineering,nanjing university of Posts and Telecommunications,nanjing 210003,china 2 school of information science and Engineering,Southeast university,nanjing 210096,china College of Communication and information Engineering Nanjing University of Posts and Telecommunications Nanjing China school of information science and Engineering Southeast University Nanjing China

In order to deal with the performance degradation resulting from the quantization error,this paper introduces the statistics of Grassmannian codebook's quantization error into relay precoding design for multirelay *** on the two-step MMSE optimization algorithm for relay precoding and receiver equalizing with full feedback under QoS requirements,we first propose a limited feedback two-step MMSE optimization scheme for relay precoding and receiver equalizing with quantization error compensation,and then we propose a limited feedback joint MMSE optimization scheme for relay precoding and receiver equalizing with quantization error compensation subject to a global power constraint at the output of *** results show that the proposed joint MMSE optimization scheme with quantization error compensation has a much lower bit-error rate than the two-step MMSE optimization scheme with quantization error compensation and the joint MMSE optimization scheme without quantization error compensation.

关键词： multi-relay precoding limited feedback minimum mean square error

Investigation of fine and complex vortex circulation structures

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science china Earth sciences 2010年第10期53卷 1552-1558页

作者： LUO ZheXian1,MA GeLan1 & PING Fan2 1 Remote Sensing College,nanjing university of information science and technology,nanjing 210044,china 2 Laboratory of Cloud-Precipitation physics and Severe Storms(LACS),Institute of Atmospheric physics,Chinese Academy of sciences,Beijing 100029,china Remote Sensing College Nanjing University of Information Science and Technology Nanjing China Laboratory of Cloud-Precipitation physics and Severe Storms (LACS) Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China

The formation and evolution of fine and complicated vortex circulation structures were investigated using a two-dimensional quasi-geostrophic barotropic model *** find that the highly localized asymmetric and complex configuration of energy transfer flux between large-and small-scale components is caused by the nonlinear interaction between a large-scale vortex with an initial axi-symmetric flow and four beta meso-scale *** complex structure is characterized by a fine pattern,which contains seven closed systems with spatial scales of less than 100 km,embedded in a positive flux wave train and a negative wave train,*** average wind speed decreased with time in the positive flux region,but was nearly unchanged in the negative flux *** pattern reveals the evolutionary asymmetry and localization of wind speed of the major *** track of the major vortex center has a trend toward the center of the negative flux center,indicating that there is a certain relation between the complex structure of the energy transfer flux and the motion of the major vortex *** results imply that the formation and evolution of the fine and complex structure should be attributed to the nonlinear interaction between the vortices at different spatial scales.

关键词： vortex complex structure non-linear interaction energy cascade

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 technology, nanjing 210044, 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 44 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.

Research on heart sound identification technology

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science china(information sciences) 2012年第2期55卷 281-292页

作者： CHENG XieFeng1,3,MA Yong2,LIU Chen1,ZHANG XueJun1 & GUO YuFeng11school of Electronic science and Engineering,nanjing university of Posts and Telecommunications,nanjing 210003,china 2school of Computer science and technology,nanjing university of science and technology,nanjing 210094,china 3Key Lab of Broudbard Wireless Communication and Sensor Network technology(nanjing university of Posts and Telecommunications),Ministry of Education,nanjing 210094,china school of Electronic science and Engineering Nanjing University of Posts and Telecommunications Nanjing China Ministry of Education Key Lab of Broudbard Wireless Communication and Sensor Network Technology (Nanjing University of Posts and Telecommunications) Nanjing China school of Computer science and technology Nanjing University of Science and Technology Nanjing China

In this article,both the basic principles and the experimental methods of identity recognition technology based on heart sounds are ***,the characteristics of heart sounds and the feasibility of heart sounds as a biometric were analyzed.A synthetic model of heart sounds was then developed based on a family of wavelets;Finally,the characteristic parameters of heart sounds were extracted by using the heart sounds linear band frequency cepstra(HS-LBFC)with a specified configuration,and the similarity distance was adopted for heart sound *** highlight the difference in two heart sound signals between the time and frequency domains,a construction method of the heart sound wavelet,a calculation method of the parameters of a synthetic model,selection of the characteristic parameters of heart sounds and the corresponding data processing technology were *** experimental results showed that the proposed method exhibited excellent performance and practicability.

关键词： biometric wavelet family of heart sounds synthetic model of heart sounds heart sounds linear band frequency cepstra(HS-LBFC)

Spatial and Temporal Variability of N, P and K Balances for Agroecosystems in china

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Pedosphere 2005年第3期15卷 347-355页

作者： SHENRun-Ping SUNBo ZHAOQi-Guo InstituteofSoilscience ChineseAcademyofSciencesNanjing210008（China）／／DepartmentofSpatialInformationScienceNanjingUniversityofInformationScienceandTechnologyNanjing210044（China） InstituteofSoilscience ChineseAcademyofSciencesNanjing210008（China）

Nitrogen, phosphorus, and potassium balances for agroecosystems in china from 1993 to 2001 were calculated at national and provincial levels using statistical data and related parameters, and their spatial and temporal variabilities were analyzed with GIS to estimate the potential impacts of nutrient N, P and K surpluses or deficits to soil, water and air. At the national scale, the N and P balances from 1993 to 2001 showed a surplus, with the nitrogen surplus remaining relatively stable from 1997—2001. Although during this period the P surplus pattern was similar to N, it had smaller values and kept increasing as the use of phosphate fertilizer increased year by year. However, K was deficient from 1993 to 2001 even though from 1999 to 2001 the K deficit decreased. The spatial analysis revealed higher N surpluses in the more developed southeastern provinces and lowest in the western and northern provinces where there was less chemical fertilizer input. The serious K deficit mainly occurred in Shanghai and Beijing municipalities, Jiangsu, Zhejiang and Hubei provinces, and Xinjiang autonomous regions. For the years 1992, 1996 and 2001, N surpluses and K deficits had significant positive spatial correlations with per capita gross domestic product (GDP), per capita gross industrial output value, and per capita net income of rural households. This showed that the level of economic development played an important role on nutrient balances in the agroecosystems.

关键词： china economic factors NPK balance spatial and temporal variability

Suppressing the disturbance in the transmission spectrum of Glan-Thompson-type prism polarizers

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Chinese Optics Letters 2010年第4期8卷 428-430页

作者：李红霞范吉阳苏富芳吴福全祝世宁 Department of Applied physics nanjing university of science and technology Department of physics Nanjing University Department of physics Southeast university Laser Research Institute Qufu Normal university Department of physics nanjing university

We analyze the random disturbance in the transmission of light through a spinning Glan-Thompsontype prism *** disturbance makes the dependence of the transmission on the rotation angle significantly deviates from the Malus cosine-squared law and severely spoils the output light *** vibration of the polarizer as it rotates combing the multi-beam-interference effect raises the disturbance. Further analysis reveals the sensitive dependence of the disturbance on the composing material of the prism gap,and the appropriate selection of such material can make the disturbance minimize to very desirable *** model results show quite good agreement with experiments.

关键词： Light sources Optical instruments Prisms

Weak martingale Hardy spaces and weak atomic decompositions

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science china mathematics 2006年第7期49卷 912-921页

作者： HOU Youliang & REN Yanbo school of mathematics and Statistics, Wuhan university, Wuhan 430072, china Department of mathematics & physics, Henan university of science and technology, Luoyang 471003, china school of mathematics and Statistics Wuhan University Wuhan China Department of mathematics & physics Henan University of Science and Technology Luoyang China

In this paper we define some weak martingale Hardy spaces and three kinds of weak atoms. They are the counterparts of martingale Hardy spaces and atoms in the classical martingale Hp-theory. And then three atomic decomposition theorems for martingales in weak martingale Hardy spaces are proved. With the help of the weak atomic decompositions of martingale, a sufficient condition for a sublinear operator defined on the weak martingale Hardy spaces to be bounded is given. Using the sufficient condition, we obtain a series of martingale inequalities with respect to the weak Lp-norm, the inequalities of weak (p ,p)-type and some continuous imbedding relationships between various weak martingale Hardy spaces. These inequalities are the weak versions of the basic inequalities in the classical martingale Hp-theory.

关键词： martingale, weak Hardy space, weak atom, atomic decomposition.