1994 Vol. 19, No. 3
This paper presents a new spline——arc spline.It tubes two arcs connecting adjacent points among a sampled series,with known tangent at each sampled point. The calculation for the parallel,the curve length and the segmenting points coordinates are simple,thus making map symbal generation simplexed.When"arclet"occurs,some specinl processing must be taken.
Artificial neural networks(ANN) has the ability of learning,adaptive and parallel proceodng.It has the robust property to noiseand pattern deformation.So using ANN may overcome the difficultiesthat can' t be solved by traditional OCR technique.ANN approach for digits of map lettering recognition beingproposed in this paper and a two hidden layers BP networks being constructed.
In this paper a method for establishing a gridded DEM from contours is discribed.The method takes into consideration the numerical and geometrical characteristics of contours,and therefore has better stability and reliability.Two methods are proposed to measure the reliability of the established DEM:comparison of the analytical surfaces and the restoration contours.
How to infer and link mine rock boundary lines is a key problem by the computer aided mapping in geological graphics of underground mine.Using artificial intelligence technique this problem has been resolved and a Automatic Inferring and Linking System of Mine Rock Boundary Lines(AISMB)is developed.The data structure,expression of knowledge,the inferring and linking procedure and methode,the realization of AISMB,etc are discussed in this paper.
The paper applies time series analysis to risky cliff observation data processing.Thus the dynamic deformation model of risky cliff is built and the good precision in calculation and forecast is obstained.It is proved that time series analysis could be widely used in data processing of risky cliff observation.
The pseudo-stereo method is developed to provide an effective tool for map revision. The method is designed for the case when significant relief displacements exist in the image and no DEM is available to correct them.The imags,however,has to provide a stereoscopic coverage.The basic idea of this method and the software developed are described then the testresults and discussion of the results are given.
This paper uses the mathod of mathematical analysis to establish an ideal mathematical model for map quality fuzzy evaluation.Subordination and fuzzy operators suitable to map quality evaluation are selected by analysis and study.This model is used in evaluating mapping quality for twelve topographical maps,and the result is satisfactory.
The authors introduced briefly the principle of relativity theory and eXpounded various relativistic effects in geodesy such as reference systems,space geodesy,gravimetry,inertial geodesy etc.Finally,the authors pointed out the existent problem which is urgent to be solved.
In this paper,the authors expounded the concept and theoretical basis of the equifrequency geoid,discussed the relation between the equi-frequency scold and the classic geoid,proposed a new method——gravitation or gravity frequency shift method——for determining geopotential differences and heisht differences,and probed the way to solve the geodetic boundary value problem by using the method of frequency-shift measurement.
This paper presents a new model of variance and covariance components estimation by applied projective transformation and representation of matrices by vectors. The method changes the quadratic estimation of varisnce and covarisnce components into the linear model.Some statistical characters of the estimate have been proved.
Based on the theory of plate kinematics and the method of space geodesy,a practicable mathematic model for monitoring of plate variation with movement and deformation is established in this paper.Also the background of tectonic setting of Qinghai-Xizang plstesu is analyzed,and then a primary scheme of geodetic monitoring network for detecting the diastrophism of Qinghai——Xizang Plateau is put forward.
After giving the solar radiation pressure model of GPS satellite,new formulas of the partial derivatives of the perturbation acceleration vector with respect to satellite position vector are led with the method of vector differential.At last the new formulas which have simpler forms and are easier for programming than that were given in[1,2] are tested nummerically.
In this paper,the air environmental pollution of Miluo City,Hunan province is taken as an example.According to the obtained data of SO2,NOx and TSP in the air,based on the national criteria of 3 degrees for the assessment. Using overstundard weisht grey situation decision method and computer to process these data,the assessment result is all that could be desired. This method will offer a new tool for urban environmental qualitative assessment.
Object-oriented Programming Language (OOPL) is a effective tool for developing and designing parallel software. In this paper,first, OOPL's classification is described. Then the parallel OOPL-ParaObject is introduced briefly. Finally,the design of the object manager of ParaObject and some parallel implementation techniques are discussed.