• Korean Journal of Remote Sensing
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• v.19 no.6
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• pp.457-464
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• 2003

Triangulated irregular network is one of the most frequently used terrain modeling methods. It represents terrain precisely using only a small amount of data, and enables fast rendering of terrain. In this paper, ridges and valleys are extracted from the terrain, and used as a set of vertices for the construction of triangulated irregular network. An experiment shows the new method reduces the time for construction of the triangulated irregular network significantly with almost equal amount of induced error.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.12 no.2
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• pp.209-218
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• 1994

This study aims to generate triangulated irregular network in a form of digital terrain model which is being increasingly used. In general, grid digital elevation model and triangulated irregular network are reasonable units for solving terrain problems. But, triangulated irregular network is an efficient alternative to grid digital elevation model because of their efficiency in storing data and their convenient data structure for accommodating irregularly spaced elevation data. Various methods represented for extracting triangulated irregular networks from grid digital elevation model, and then algorithm that get accurate results for triangulation with their data set was introduced. The new approach for triangulation in this study uses the Elevation and Changeable Distance criterion, and adding interpolation points and restricted constraint lines can generate triangulated irregular network which is more close to real surface. This made database efficient construction and could be used for many applications of geo-spatial information system.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.8 no.2
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• pp.1-8
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• 1990

A regular grid or a triangulated irregular network is generally used as the data structure of digital terrain models. A Regular grid is simple and easy to manipulate, but it can't describe well terrain surface features and requires vast volumes of data. In the meantime, a triangulated irregular network has complex data structure, but it can describe well terrain surface features and can achieve the accuracy suitable to its application with relatively little data. This paper aims at the construction of efficient digital terrain models by the improvment of a triangulated irregular network based on Delaunay triangulation. Regular and irregular data set are sampled from existing contour maps, and the efficiency and the accuracy of the two data structures are compared.

• Journal of The Korean Society of Agricultural Engineers
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• v.48 no.4
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• pp.3-12
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• 2006

Watershed is the land area that contributes runoff to an outlet point. To delineate an watershed, watershed delineation using GIS that contains grid data structure is the most general method. Some researchers have studied to implement algorithms that revise the TIN topography since it is difficult to delineate watershed boundary more accurately. In this study kruskal's greedy algorithm and triangulated irregular network (TIN) were used to delineate a watershed. This method does not require a conversion from to DEM in grid and automatically obtain(generates) the oulet points. Delineation algorithm was tested in Geosan-gun, Chung-cheongbuk-do and get small watershed areas. Finally, kruskal's algorithm could operate more precisely with revision algorithm.

• Journal of Korean Society for Geospatial Information Science
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• v.6 no.2 s.12
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• pp.133-141
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• 1998

Terrain modelling is composed of a method using the rectangular grid and another using the triangulated irregular network. The method using the triangulated irregular network is most widely used because it can express the characteristics of the terrain well with only a small amount of information on the terrain and also reduces the rendering time. The process of extracting the surface-specific point and a triangular process is needed to construct such triangulated irregular network. This paper concentrates on the process of extracting the surface-specific point. The 8-direction neighborhood method and other transformed methods of the former method are frequently used to extract the surface-specific point. Another method which eliminates the unnecessary points using the Polygon reduction method is also suggested However, the 8-direction neighborhood method has a big fault of also drawing out some unnecessary points. To resolve such problem, we suggest a method of extracting the surface-specific point using the cross section of the terrain. This method reduces the time to extract the surface-specific point and enables a more precise extraction with less terrain information.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.2
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• pp.325-334
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• 1994

Modern society is the age of a high state of information and demands more effective land information. Moreover, because the use of land in Korea is intensive, Korea requires more synthetic and systematic geographical information for which the digitizing of terrain is prerequisite. This study aims at development of the data structure which is suitable to the digitizing of terrain for Geographical Information System(GIS). Regular grid has been used generally in Digital Terrain Model(DTM), for it is easy to manipulate. But regular cannot reflect well the terrain surface features. In the meantime, Triangulated Irregular Network(TIN) has complex data structure, but it can describe well terrain surface features and is useful in various applications. In this paper the method which constructs effective DTM by improving TIN has been researched.

• Journal of The Korean Society of Agricultural Engineers
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• v.49 no.6
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• pp.37-46
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• 2007

In designing the structure, the stress path is the basic data. But the stress path is not standardized to analysis the structure. So the one-dimensional frame element structure model with the triangle irregular network is used to solve the problem. And the refined evolutionary structural optimization(RESO) used in structural topology optimization is applied to this study. Through this process, the search method of the stress path is advanced and the burden of the calculation. is reduced.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 1995.10a
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• pp.31-31
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• 1995

TIN은 Triangulated Irregular Network의 약자로 불규칙한 대소삼각형의 집합으로 삼각망을 구성, 지표면을 Digital Terrain Model로 만드는 기법이다. 지표면(해저지형포함)은 수치화된 등고선의 벡터 데이터와 점의 표고데이터 또는 표고 평행배열의 Raster데이터로부터 모형화되며 또는 제 3의 방법인 TIN에 의해 모형화된다. 이 TIN에 의한 도형은 컴퓨터가 위성측량, 항공측량, 광파측량 또는 음차수심측량등 측량결과를 받아 어떤 특정 프로그램을 구동 삼각형의 정점에 해당하는 점의 X, Y, Z의 좌표로부터 닫한 삼각형을 작성한다. (중략)

• Korean Journal of Remote Sensing
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• v.22 no.1
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• pp.49-61
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• 2006

The lifting scheme has been found to be a flexible method for constructing scalar wavelets with desirable properties. In this paper, it is extended to the UDAR data compression. A newly developed data compression approach to approximate the UDAR surface with a series of non-overlapping triangles has been presented. Generally a Triangulated Irregular Networks (TIN) are the most common form of digital surface model that consists of elevation values with x, y coordinates that make up triangles. But over the years the TIN data representation has become an important research topic for many researchers due its large data size. Compression of TIN is needed for efficient management of large data and good surface visualization. This approach covers following steps: First, by using a Delaunay triangulation, an efficient algorithm is developed to generate TIN, which forms the terrain from an arbitrary set of data. A new interpolation wavelet filter for TIN has been applied in two steps, namely splitting and elevation. In the splitting step, a triangle has been divided into several sub-triangles and the elevation step has been used to 'modify' the point values (point coordinates for geometry) after the splitting. Then, this data set is compressed at the desired locations by using second generation wavelets. The quality of geographical surface representation after using proposed technique is compared with the original UDAR data. The results show that this method can be used for significant reduction of data set.

• Journal of Korean Society for Geospatial Information Science
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• v.11 no.1 s.24
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• pp.77-82
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• 2003

Geographic information system extends several teamed circles so for and took in application step. Specially, GIS is applying much in civil engineering works field, and is trying to express terrain numerically and look for true value. It is very important that express terrain, can become important parameter to do three-dimensional analysis in later. We are using irregularity triangulation network mainly to express these terrain. In this study, calculated volume of topography by irregularity triangulation by developed formula.