• Journal of Korean Society for Geospatial Information Science
• /
• v.15 no.4
• /
• pp.3-9
• /
• 2007

Recently, the efforts of systematic understanding and utilization of geographic phenomenon for human life as a important factor among activity of mankind are increasing. It is necessary to express topography connected with space. Especially, the technology of geographic analysis using DEM can supply the information rapidly and accurately about elevation and terrain slope of the subject area under the necessity of high 3D quality geographic information. In this study, creating more precise DEM derived from LiDAR data, quantitative analysis on the subject area about elevation and terrain slope is done under comparison with Digital Topographic map Scale 1:1000. LiDAR data is more detailed than Digital Topographic map to express the elevation of the subject area ($39.89{\sim}77.48m$), and terrain slope by analysis using DEM derived from LiDAR data come out minutely about 90%. It can be concluded that the LiDAR data is very applicable and accurate for 3D topographic terrain slope analysis.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.28 no.6
• /
• pp.350-360
• /
• 2016

In order to investigate characteristics of waves and currents varying in space in the Haeundae coast in winter, numerical simulations by using a 2-D spectral wave model(SWAN) and 2-DH hydrodynamic model(Delft3D) were carried out in this study. The results of numerical simulations were validated with the field data collected at several different locations in the study area in February, 2014. From the numerical simulations, it was found that waves and currents were significantly influenced in terms of direction and magnitude by bottom topography characterized by straggling rock crops covered with sea grasses. The coupling of SWAN and Delft3D models also revealed that alongshore currents directing from the east to the west were developed in the nearshore, due to the influence of larger waves with the main incident direction from the east.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
• /
• 2003.10a
• /
• pp.391-396
• /
• 2003

The digital map expresses natural topography and artificial things with 3D position coordinates in the computer such as the road, railway, building, river, mountain, paddy and dryland. Therefore, those should contribute to the information-oriented society by maintaining information and providing it to users quickly. However it is difficult to maintain the most recent topographic information all the time because of restricted budget and time. The purpose of this study is to investigate and analyze the updating area of the digital map using remotely sensed data, and to furnish the useful information reducing cost and time. To predict updating area of the digital map, we applied the urban changes analysis method to Landsat TM images from produced date of the digital map to up-to-date. Classification method for urban change analysis applied single band process algorithm. This study presents that updating area of the digital map is predicted by only the rate of 40% on total research area.

• Journal of the Korean Society for Precision Engineering
• /
• v.21 no.12
• /
• pp.60-66
• /
• 2004

Increasing demands on precision machining of 3D free-form surface have necessitated the tool to move smoothly with varying feedrate. To this regard, parametric interpolators such as NURBS (Non-Uniform Rational B-Spline) interpolator have been introduced in CNC machining system. Such interpolators reduce the data burden in NC code, increase data transfer rate into NC controller, and finally give smooth motion while machining. In this research, a new concept to control cutting load in NURBS Interpolator was tried based on the curvature of curve. This is to protect cutting tool, and to have good machinability. For proof of the system, cutting force and surface topography were evaluated. From the experimental results. the interpolator is good enough for machining a free-form surface.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1995.10a
• /
• pp.397-401
• /
• 1995

ESPI(Electronic Speckle Pattern Interfermetry) is an optical technique to measure surface deforamtion of engineering components and materials in industrial ares. This optical method is capable of providing full-field results with high spatial resolution, high speed and is the non-contact technique. One of important application aspects using electronic speckle pattern interferometry is to generate contours of a diffuse object in order to provide data for 3-D shape analysis and topography measurement. The contouring method by modified dual-beam speckle pattern interferometry is proposed. We introduce a shift of the illumination beams through optical fiber in order to obtain the contour fringe patterns. The speckle pattern correlation technique is suitable for providing measurement range from millimeters to several centimeters. The complete geometric analysis of the contoretical and experimental results are obtained.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.28 no.9
• /
• pp.1276-1283
• /
• 2004

This study is an inspection of press forming product and mould using reverse engineering system. The inspection process on production field involves a lot of errors because of the hand-work so we focussed on improving the measured precision through performing the effective inspection using 3D non-contact scanner. By so doing that, we improved the precision of press forming product by analyzing the cause following the inspection result. Through the inspection, we applied it to the reverse engineering and we could improve the inspection process.

• Journal of Information Technology Applications and Management
• /
• v.12 no.1
• /
• pp.111-123
• /
• 2005

Many indexing methods were proposed so that process moving object efficiently. Among them, indexing methods like the 3D R-tree treat temporal and spatial domain as the same. Actually, however. both domain had better process separately because of difference in character and unit. Especially in this paper we deal with limited region such as indoor environment since spatial domain is limited but temporal domain is grown. In this paper we present a novel indexing structure, namely STS-tree(Separation of Time and Space tree). based on limited region. STS-tree is a hybrid tree structure which consists of R-tree and one-dimensional TB-tree. The R-tree component indexes static object and spatial information such as topography of the space. The TB-tree component indexes moving object and temporal information.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.30 no.6 s.249
• /
• pp.713-721
• /
• 2006

Micro-drill wear deteriorates accuracy and productivity of the micro components. In order to improve productivity and qualify of micro components, it is required to investigate micro-drill wear exactly. In this study, a machine vision system is proposed to measure the wear of micro-drills using a precision servo stage. Calibration experiments are conducted to compensate for the machine vision system. In this paper, worn volume, area and length are defined as wear amounts. Micro-drill wear is reconstructed as the 3D topography and the quantized wear amount by using the shape from focus (SFF) method and wear parameters. Experiments have been conducted with HSS twist micro-drills and SM45C carbon steel workpieces. Validity of the proposed machine vision system is confirmed through experiments.

• 한국지구물리탐사학회:학술대회논문집
• /
• 2004.08a
• /
• pp.8-21
• /
• 2004

Examples of GPR survey results at a variety of archaeological sites are presented. Several new analyses which include static corrections for the tilt of the GPR antenna are shown for imaging of burial mounds with significant topography. Example archaeological site plans developed from GPR remote sensing of Roman and Japanese sites are given. The first completely automated GPR survey, using only Global Positioning Satellite navigation to create 3D data volumes, is employed for a site in Louisiana to detect lost graves of the Choctaw Indian Tribe.

• Proceedings of the KSRS Conference
• /
• 2003.11a
• /
• pp.85-92
• /
• 2003

Application of traditional aerial survey technologies for topographic mapping purposes has a number of principal problems. The growing worldwide acceptance of digital orthophotos has understood this need. Many trekking and expedition teams are expecting digital orthophoto and consequently 3D animation of the highest peaks and possible trekking routes, camping sites and information on how difficult the routes may be. In recent years, inexpensive computers and advance of computer technologies contributed to the rapid development of digital photogrammetry (Dowman et al., 1992; Heipke, 1995). Successful implementation of digital photogrammetric workstations in mapping have been found in various disciplines (Chen et al., 1998; Skalet et al., 1992). This paper highlights the results of the conventional photogrammetry and the possible advantages of digital photogrammetry over these and also the problems, issues and implications during digital Photogrammetric processing of high mountainous region in Asia.