• Journal of the Korean association of regional geographers
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• v.13 no.5
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• pp.563-575
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• 2007

This study aims to investigate a possibility of using topographic information by web mapping in open environments. Web mapping intends to focus on a map analysis and application of the function and geo-visualization. Functions of Web topographic info-map include a spatial analysis, enlargement and minimization, movement, landuse information, user-controling 3 dimension map, landform cross-section analysis, shortest path analysis. The web system adopts SVG(scalable vector graphics), MYSQL, PHP, XML for mapping. SVG has open source policy, so everyone can use it, as well, it is effective on flexible database linkage, cartographic representation. 3D map is intended to represent 3D map by user-controlled sunshine putting pixel opacity by elevation values after making DEM. Landform is designed to show a cross-section analysis and statistics by retrieving height information from database engine with clicking two points on the map. Shortest path analysis within regions uses Dijkstra's algorithm. Near future, resultantly, the area of WebGIS will have to meet more social demands for use-created geo-information and application, so more researches are needed to be web mapping more applicable for users.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.141-143
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• 2003

The aim of this study is to evaluate the susceptibility of landslides at Clicap area, Indonesia , using a Geographic Information System (GIS). Landslide locations were identified from field surveys. The topographic and geological map were collected and constructed into a spatial database using GIS. The factors that influence landslide occurrence, such as slope, aspect and curvature of topography, were calculated from the topographic database and lihology and fault was extracted from the geological database. Then landslide susceptibility was analyzed using the landslide-occurrence factors by likelihood methods. The results of the analysis were verified using the landslide location data. The GIS was used to analyze the vast amount of data efficiently . The results can be used to reduce associated hazards, and to plan land use and construction.

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 2005.09a
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• pp.98-102
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• 2005

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2001.11a
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• pp.81-85
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• 2001

• Journal of Cadastre & Land InformatiX
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• v.48 no.1
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• pp.153-167
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• 2018

Despite many criticisms that topographic survey data for the official land price appraising collected annually using field survey method might be inaccurate, there is only few concrete research on it. This paper investigated whether the topographic survey data collected by a local government using field survey method is consistent with the data analyzed using the digital elevation model to examine its accuracy. The accuracy analysis indicated that 324 out of 1537 lots of land have inconsistent results which means the ratio of inconsistency is 17.36%. Among 11 areas studied, five had the inconsistency ratio above 20% while the worst one had 38.71%. The inconsistency ratio is generally higher for the rough terrain with irregular slope and high altitude while it is relatively lower for the terrain with smooth landform. The analysis results imply that there are limitations in investigating the topology by field survey method. Therefore, the official land price appraising policy should set precise criterion and change over to highly accurate geographic information analysis method to effectively and accurately examine topology, given the fact that the topology of the Republic of Korea has complicated features with irregular slope and altitude.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.568-571
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• 1997

Recently, the number of techniques for analyzing medical images has been increasing in computer vision, employing X-ray CT images, ultrasound images, MR images, moire topographic images, etc. Spinal deformity is a serious problem especially for teenagers and medical doctors inspect moire topographic images of their backs visually for the primary screening. If a subject is normal, the moire image is almost symmetric with respect to the middle line of the subject's back, otherwise it shows asymmetric shape. In this paper, an image analysis technique is described for discriminating suspicious cases from normal in human spinal deformity by recognizing asymmetric moire images of human backs. The principal axes which are sensitive to asymmetry of the moire image are extracted at two parts on a subject's back and their angles are evaluated with respect to the detected middle line of the back. The two angles compose a 2-D feature space and inspected cases are divided into two clusters in the space by a linear discriminant function based on the Mahalanobis distance. Given 120 cases, 60 normal and 60 abnormal, the leave-out method was applied for the recognition and 75% recognition rate was achieved.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.05
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• pp.362-365
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• 1997

To visualize electrical activities in the cerebral cortex, we develop the 3D topographic mapping system based on PC. For this work, we utilize OpenGL tool and an optimized interpolation method known as 3D barycentric algotithm, which has a little computational complexity. OpenGL processes the 3D coordinates, and 3D barycentric algotithm interpolates to get overall EEGs with EEGs measured from finite electrodes on 3D. To prove validity of this algorithm on the PC-based system, we developped Windows-based 3D topographic mapping program using the Barycentric algorithm. The result showed that the performance of this system is comparable to that of workstation in terms of speed and precision. Also, the result of clinical test was the same as that of a EEG technician's analysis.

• Journal of The Geomorphological Association of Korea
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• v.24 no.1
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• pp.1-12
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• 2017

Planting trees is a very common practice in the coastal dunefields of South Korea as a way to stabilize dune landscapes and protect inland residential areas from strong winds and blown sands. On the other hand, disturbing the original foredune environment may deteriorate the ability of coastal landsto recover from coastal erosion after storms, causing a retreat of coastline. However, there is little information of this sort on the surface of forested dunefields. Airborne LiDAR or drone-based mapping is not easily applicable in such areas. In this study, we developed a digital terrain model of Dasari dunefields, Chungnam Province, based on direct topographic surveys with real-time kinematic GPS and total stations. We also analyzed previous two aerial photographs taken in 1947 and 1966, in order to detect an older landforms of the dunefields. Results suggested that there have been little changes in geomorphology of the Dasari dunefields for the last 50 years, despite continued tree plantings. Today, there are remains of U-shaped structures such as blowouts and parabolic dunes in the dunefields.

• Journal of Gastric Cancer
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• v.21 no.3
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• pp.236-245
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• 2021

Purpose: The numeric N stage has replaced the topographic N stage in the current tumor node metastasis (TNM) staging in gastric carcinoma. However, the usefulness of the topographic N stage in the current TNM staging system is uncertain. We aimed to investigate the prognostic value of the topographic N stage in the current TNM staging system. Materials and Methods: We reviewed the data of 3350 patients with gastric cancer who underwent curative gastrectomy. The anatomic regions of the metastatic lymph nodes (MLNs) were classified into 2 groups: perigastric and extra-perigastric. The prognostic value of the anatomic region was analyzed using a multivariate prognostic model with adjustments for the TNM stage. Results: In patients with lymph node metastasis, extra-perigastric metastasis demonstrated significantly worse survival than perigastric metastasis alone (5-year survival rate, 39.6% vs. 73.1%, respectively, P<0.001). Extra-perigastric metastasis demonstrated significantly worse survival within the same pN stage; the multivariate analysis indicated that extra-perigastric metastasis was an independent poor prognostic factor (hazard ratio=1.33; 95% confidence interval=1.01-1.75). The anatomic region of the MLNs improved the goodness-of-fit (likelihood ratio statistics, 4.57; P=0.033) of the prognostic model using the TNM stage. Conclusions: The anatomic region of MLNs has an independent prognostic value in the numeric N stage in the current TNM staging of gastric carcinoma.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.27 no.1
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• pp.33-47
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• 2022

In this study, distribution of submarine sand ridges in the coastal waters of Korea was surveyed using multibeam echo sounder data, and the topographic characteristics of each region were identified. For this purpose, the DEM (Digital Elevation Model) data was generated using depth data obtained from the Yellow Sea and the South Sea by Korea Hydrographic and Oceanographic Agency, and then applied the TPI (Topographic Position Index) technique to precisely extract the boundary of the sand ridges. As a result, a total of 200 sand ridges distributed in the coastal waters were identified, and the characteristics of each region of the sedimentary sediments were analyzed by performing statistical analysis on the scale (width, length, perimeter, area, height) and shape (width/length ratio, height/width ratio, linear·branch type, exposure·non-exposure type). The results of this study are expected to be used not only for coastal navigational safety, but also for marine naming support, marine aggregate resource identification, and fisheries resource management.