• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.902-904
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• 2003

The main objective of this paper is to investigate the potential utility of multisensor remotely sensed data for improved coastal wetland mapping. Five data fusion models, three algebraic models (Multiplicative (MT), Brovey (BT) and Wavelet transform (WT)) and two spectral domain models (Principals component transform (PCT) and Intensity-Hue-Saturation (IHS)) were implemented and tested over the multisensor data. The fused images were then compared based on visual and statistical approaches. The results show that the wavelet transform provides greater flexibility for combining optical data sets and has good potential for preserving the spatial and spectral content of the original images . However, this model yields poor information when combining optical and microwave data. Brovey transform is more reliable for fusing optical and microwave image data and yields improved information about different wetland features of the coastal zone.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.93-95
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• 2003

Vector-borne diseases have been the most important worldwide health problem for many years and still represent a constant and serious risk to a large part of the world’s population. GIS and RS is used to evaluate and model the relationships between environmental factors/indicators and the incidences of viral diseases. The aim of the study is to identify the risk factors in Dengue Haemorrhagic Fever DHF) from the highest prevalence area and lowest prevalence area in Sukhothai province, Thailand using statistical, spatial and GIS Modeling. Results obtained in the study of the Dengue show that it is now possible to identify and localize precisely environmental indicators and factors of viral diseases.

• Journal of Welding and Joining
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• v.16 no.6
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• pp.68-76
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• 1998

A CCD camera with a laser stripe was applied to realized the automatic weld seam tracking. The 3-dimensional information obtained from the vision system made it possible to generate the weld torch path. The adaptive Hough transformation was used to extract laser stripes an to obtain specific weld points. It takes relatively long time to process image on-line control using the basic control using the basic Hough transformation, but it has a tendency of robustness over the noises such as spatter. For this reason, it was complemented with adaptive Hough transformation to have an on-line processing ability for scanning specific weld points. The dead zone, where the sensing of weld line is impossible, was eliminated by rotating the camera with its rotating axis centered at the weld torch. When weld lines were detected, the camera angle was controlled in order to get the minimum image data for sensing of weld lines. Consequently, the image processing time was reduced.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.1105-1109
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• 1995

A CCD-camera, which is structured with vision system, was used to realize automatic seam-tracking system and 3-D information which is needed to generate torch path, was obtained by using laser-slip beam. To extract laser strip and obtain welding-specific point, Adaptive Hough-transformation was used. Although the basic Hough transformation takes too much time to process image on line, it has a tendency to be robust to the noises as like spatter. For that reson, it was complemented with Adaptive Hough transformation to have an on-line processing ability for scanning a welding-specific point. the dead zone,where the sensing of weld line is impossible, is eliminated by rotating the camera with its rotating axis centered at welding torch. The camera angle is controlled so as to get the minimum image data for the sensing of weld line, hence the image processing time is reduced. The fuzzy controller is adapted to control the camera angle.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.685-688
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• 2004

Fresh water discharge from the sea floor strongly affects a coastal ecology and the diffusion of contaminants. Much fresh water discharge has been found in the edge of Kurobe alluvial fan, in which annual rainfall is over 4000mm and there is abundant groundwater. However, it is difficult to find the groundwater discharge, thus the search of possible areas with some remote sensing tools is required. Because the temperature of the discharge point is relatively low compared with the surrounding sea water surfaces, there is a possibility to detect the area as an irregular zone of thermal infrared images. Two anomalous temperature zones, which have no surface streams from rivers, are detected by ASTER thermal-infrared images. One of them was verified as the groundwater discharge point by dives. In addition, the distribution of water table under the land side of the two areas is also detected as irregular zones by a ground-penetrating radar

• Proceedings of the KSRS Conference
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• 2008.03a
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• pp.29-34
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• 2008

최근에 객체의 경계가 분명하게 나타나는 고해상도 위성영상을 분석하는 연구가 활발히 이루어지고 있다. 고해상도 영상을 이용해 도시지역을 세분화하여 연구하려고 할 때 분석의 범위는 임의로 결정되는 경우가 많다. 사전정보가 충분하다면 임의로 결정하는 것이 가능하지만 그렇지 않을 경우 영상만을 이용해 연구 지역의 최적 분석범위를 결정하는 것은 쉽지 않다. 이 연구에서는 영상자료의 베리오그램을 작성하고 이론적 베리오그램의 상관거리를 통해 최적의 분석범위를 결정하고자 하였다. 베리오그램의 상관거리는 객체의 크기와 객체사이의 거리가 반영된 객관적인 수치이므로 사전자료가 없는 경우 효과적으로 기본 분석단위를 결정하는데 도움을 줄 수 있을 것으로 기대된다.

• Korean Journal of Remote Sensing
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• v.2 no.2
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• pp.95-105
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• 1986

The geomorophology of the tidal near $K\breve{u}$m river estuary on the west coast of Korea was studied using satellite images. There Landsat image of different tidal moment were geometrically corrected to be overlapped one another. Then topographic contours were extracted for the analysis with concept of 3-D. According to the morphological analysis, the tidal flats around $K\breve{u}$m river estuary area can be classified in three morphologically different groups: one is developped in a belt type along the shore; another is a delta type in the estuary; the other is developped between the shore line and islands. The morphological characteristics of the tidal flats in the study area seems to be mainly influenced by the tidal dynamics which are very storg on the weatern coastal zone of Korea. However the waves and human activities seem also to be important in some part of the area.

• Korean Journal of Remote Sensing
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• v.20 no.3
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• pp.163-173
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• 2004

The objective of this study is to develop a method to generate micro-relief digital elevation model (DEM) data of the tidal mudflats using multi-temporal Landsat Thematic Mapper (TM) data. Field spectroscopy measurements showed that reflectance of the exposed mudflat, shallow turbid water, and normal coastal water varied by TM band wavelength. Two sets of DEM data of the inter-tidal mudflat area were generated by interpolating several waterlines extracted from multi-temporal TM data acquired at different sea levels. The waterline appearing in the near-infrared band was different from the one in the middle-infrared band. It was found that the waterline in TM band 4 image was the boundary between the shallow turbid water and normal coastal water and used as a second contour line having 50cm water depth in the study area. DEM data generated by using both TM bands 4 and 5 rendered more detailed topographic relief as compared to the one made by using TM band 5 alone.

• Korean Journal of Remote Sensing
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• v.25 no.6
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• pp.501-505
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• 2009

Quasi-linear bright features persistently appeared on ENVISAT ASAR images as well as X-SAR images along the tidal channels in Gyung-Gi Bay, Korea during the ebb tides. These features are induced by spatial backscatter variations caused by surface convergence (divergence) through the interaction between tidal currents and bathymetry. In order to validate this mechanism, a numerical tidal model simulation is performed on the realistic bathymetry with the tidal boundary conditions. The tide model reproduces the current convergence zone along the tidal channel during the ebb tides, which exactly coincides with the location of bright line features on SAR images.

• Korean Journal of Materials Research
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• v.9 no.11
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• pp.1083-1087
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• 1999

Microstructures and the gas-sensing characteristics of the $\textrm{SnO}_2$ thin films were studied, which were deposited at various conditions (rf power, sample temperature, $\textrm{O}_2$/Ar ratio) by the rf magnetron sputtering. As a result, six typical microstructures were derived, such as amorphous(A), amorphous mixed with polycrystalline grains (A+P), polycrystalline with random crystalographic orientation (P), fine columnar (FC), coarse columnar (CC) and Zone T (T) with dense fiberous structure. Typically, A, A+ P, and P structures were formed when no $\textrm{O}_2$ was added to the sputter gas, whereas FC, CC, and T structures were obtained when $\textrm{O}_2$ was added. The A structure formed at low rf power and low temperature, the A+P at high rf power and low temperature, and the P at high rf power and high temperature. The FC structure was obtained at low rf power and low temperature. the CC at low rf power and high temperature, and the T at high rf power and low temperature. Results of the gas-sensing test of the sensor chips fabricated from the typical films indicated that the fine columnar microstructure shows the highest sensitivity both at $300^{\circ}C$ and $400^{\circ}C$. It was proposed that this is due to the high specific surface area of the micro-columns.