實體三維緩沖區(qū)生成與分析方法研究.pdf

1、南京師范大學(xué)碩士學(xué)位論文實體三維緩沖區(qū)生成與分析方法研究姓名：王海霞申請學(xué)位級別：碩士專業(yè)：地理學(xué)；地圖學(xué)與地理信息系統(tǒng)指導(dǎo)教師：閭國年2009-05-17Abstract III Abstract Spatial buffer analysis is automatically constructing a certain distance zonal or crustose areas around point, line, fac

2、e, solid of a object, to identify radiation range for objects near these entities or objects, and so as to provide evidence for a certain analysis or decision. Spatial buffer analysis is one of the important and basic sp

3、atial analysis functions of geographic information system, which has extensive application in transportation, forestry, tourism management, urban planning, environment and ecology protection, and so on. At present, there

4、 are two basic methods for 3D buffer generation: raster method and vector method. Raster method principle is simple, limited by precision and large memory occupying, data processing capacity is restricted by machine hard

5、ware equipment. By contrast, vector method principle is complex, the problem of precision can be effectively solve, which has extensive application prospects. But vector method is applied to convex body buffer generation

6、 on the current, relational spatial analysis hasn't been conducted yet, which can't satisfy practical requirement. To overcome the problems mentioned above, 3D buffer generation algorithm based on vector and spat

7、ial query method based on 3D buffer are proposed in the paper, provided a better solution method for 3D buffer analysis. The research contents and achievements of this paper are as follows: (1) Based on Minkowski sum alg

8、orithm, propose a formal definition of buffer generation for 3D solid. The 3D buffer is defined by the Minkowski sum with 3 G , which is the solid object of 3D spatial, and the 3 R , which is the sphere of radius is bu

9、ffer radius and spherical center is coordinate origin. (2) Research on buffer generation algorithm for 3D solid. Point object buffer can be approached by using polyhedron being proximate sphere. For line object, its buf

10、fer can be reached by uniting solid swept volume in which the feature is as medial axis and boundary point feature buffers. And face object, its buffer can be generated by extending face upward and downward along the nor

11、mal direction unites boundary line feature buffers. Finally, solid buffer is constructed by union operation between solid boundary buffer and solid itself. In the buffer algorithm, the conception of subdivision times nam

12、ely precision degree of buffer is proposed for the precision requirements of different appcication. If buffer radius and subdivision times are definite, buffer of different solid can be created. (3) The essence of spati