By using remote sensing image data of Landsat-5 TM (1988, 1995 and 1998) and Landsat-7 ETM (2002), remote sensing image data, land-use map and DEM had been put in the same coordinate system and projection. In ArcView,...By using remote sensing image data of Landsat-5 TM (1988, 1995 and 1998) and Landsat-7 ETM (2002), remote sensing image data, land-use map and DEM had been put in the same coordinate system and projection. In ArcView, all data had been rasterized as grid data of 30 m×30 m. By Fragstats, landscape pattern indexes had been calculated. Based on the average area, patch density, landscape isolation, boundary density, shape index, fractal dimension, aggregation degree, diversity and evenness index, landscape pattern at different periods and its evolution had been analyzed, revealing the differentiation of spatio-temporal change of landscape pattern at both banks of Pearl River Estuary.展开更多
In this paper, we reveal the multiple boundary layer phenomena of the solution of nonlinear higher order elliptic equations with perturbation both in boundary and in operator, and provide a method to find uniformly va...In this paper, we reveal the multiple boundary layer phenomena of the solution of nonlinear higher order elliptic equations with perturbation both in boundary and in operator, and provide a method to find uniformly valid asymptotic solution of arbitrary order for these types of problems.展开更多
This paper is on fuzzy decision theory and information security theory which are mutually independent and engrafted. This paper presents both-branch fuzzy decision and problems on decision encryption-authentication, p...This paper is on fuzzy decision theory and information security theory which are mutually independent and engrafted. This paper presents both-branch fuzzy decision and problems on decision encryption-authentication, puts forward two kinds of both-branch fuzzy decision on X: both-branch fuzzy decision on X having bounded domains X = X+∩X- ={x0}, both-branch fuzzy decision on X havingoverlapping domains X* = X+∩X- = {x_1~*,x_2~*,…,x_1~*}. It presents single branch separate-separate out theoremof both-branch fuzzy decision on X, single branch superposition theorem of both-branch fuzzy decision, exclusive-decompose principle of both-branch fuzzy decision. This paper presents encryption-authentication theorem of decision by engrafting information security theory and technique with both-branch fuzzy decision, and provides encryption-decryption and signature-authentication of both-branch fuzzy decision.展开更多
Physical model tests were counducted to predict local scour and maximum scour depth around the large diameter cylinders located in the (sand) seabed under the action of both wave and current . According to the result ...Physical model tests were counducted to predict local scour and maximum scour depth around the large diameter cylinders located in the (sand) seabed under the action of both wave and current . According to the result of tests, an analysis was made on all the factors influencing the scour. The results shows that for the seabed with relative fine grains in shallow water (0.07<h/L≤0.28),when the relative diameter D/L of the cylinder is within 0.3 0.7,the main effective scour factors around the cylinder in the seabed are diameter D of the cylinder, the wave height H, the wave length L, the velocity V c of the current and the parameters related to the seabed soil texture. The main parameters influecing the maximum scour depth were analyzed, and the test data were syntherized, to obtain the formula predicting the scour depth around the large diameter cylinder under the of both wave and current.展开更多
基金Supported by Natural Science Foundation of China(40534019)~~
文摘By using remote sensing image data of Landsat-5 TM (1988, 1995 and 1998) and Landsat-7 ETM (2002), remote sensing image data, land-use map and DEM had been put in the same coordinate system and projection. In ArcView, all data had been rasterized as grid data of 30 m×30 m. By Fragstats, landscape pattern indexes had been calculated. Based on the average area, patch density, landscape isolation, boundary density, shape index, fractal dimension, aggregation degree, diversity and evenness index, landscape pattern at different periods and its evolution had been analyzed, revealing the differentiation of spatio-temporal change of landscape pattern at both banks of Pearl River Estuary.
文摘In this paper, we reveal the multiple boundary layer phenomena of the solution of nonlinear higher order elliptic equations with perturbation both in boundary and in operator, and provide a method to find uniformly valid asymptotic solution of arbitrary order for these types of problems.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 70271048) the Natural Science Foundation of Shandong Province (Y2001G07).
文摘This paper is on fuzzy decision theory and information security theory which are mutually independent and engrafted. This paper presents both-branch fuzzy decision and problems on decision encryption-authentication, puts forward two kinds of both-branch fuzzy decision on X: both-branch fuzzy decision on X having bounded domains X = X+∩X- ={x0}, both-branch fuzzy decision on X havingoverlapping domains X* = X+∩X- = {x_1~*,x_2~*,…,x_1~*}. It presents single branch separate-separate out theoremof both-branch fuzzy decision on X, single branch superposition theorem of both-branch fuzzy decision, exclusive-decompose principle of both-branch fuzzy decision. This paper presents encryption-authentication theorem of decision by engrafting information security theory and technique with both-branch fuzzy decision, and provides encryption-decryption and signature-authentication of both-branch fuzzy decision.
基金Project supported by the National Natural Science Foundation of China (Grant No: 59979003).
文摘Physical model tests were counducted to predict local scour and maximum scour depth around the large diameter cylinders located in the (sand) seabed under the action of both wave and current . According to the result of tests, an analysis was made on all the factors influencing the scour. The results shows that for the seabed with relative fine grains in shallow water (0.07<h/L≤0.28),when the relative diameter D/L of the cylinder is within 0.3 0.7,the main effective scour factors around the cylinder in the seabed are diameter D of the cylinder, the wave height H, the wave length L, the velocity V c of the current and the parameters related to the seabed soil texture. The main parameters influecing the maximum scour depth were analyzed, and the test data were syntherized, to obtain the formula predicting the scour depth around the large diameter cylinder under the of both wave and current.
