• Journal of the Korean Geophysical Society
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• v.2 no.1
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• pp.75-88
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• 1999

A recent major subject of geophysical exploration is research into 3-D subsurface imaging with a composite information from the various geophysical data. In an attempt to interpret Schlumberger sounding data for the study area in 2-D and 3-D view, resistivity imaging was firstly performed and then pseudo-3-D resistivity volume was reconstructed by interpolating several 1-D resistivity plots. Electrical resistivity discontinuities such as fracture zone were successfully clarified in pseudo-3-D resistivity volume. The low resistivity zone mainly associated with fracture zone appears to develop down to granitic basement in the central part of the study area. Seismic velocity near the lineament is estimated to be approximately as small as 3,000 m/s, and weathering-layer for the southeastern part is interpreted to be deeper than for the northwestern part. Geophysical attributes such as electrical resistivity, seismic velocity, radioactivity for the Chojeong Area were analysed by utilizing a GIS software Arc/Info. The major fault boundaries and fracture zones were resolved through image enhancement of composite section (electrical resistivity and seismic refraction data) and were interpreted to develop in the southeastern part of the area, as characterized by low electrical resistivity and low seismic velocity. However, radioactivity attribute was found to be less sensitive to geological discontinuities, compared to resistivity and seismic velocity attributes.

• Journal of the Korean Association of Geographic Information Studies
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• v.22 no.1
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• pp.19-27
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• 2019

This study is to measure the length of the Demilitarized Zone and the Military Demarcation Line(MDL) on the Korean Peninsular. For this purpose, maps of the Armistice Agreement Volume II were used. These maps are nine sheets. In order to extract the MDL shown on the map, coordinates were assigned to the scanned image maps using the georeferencing module of ArcGIS based on the sheet line coordinates. The accuracy of the extracted vectors was checked by overlaying them on the maps of the Armistice Agreement Volume II. And I tried to validate these vectors through comparative analysis with vectors extracted from Kim(2007). Vectors extracted from Kim(2007) had errors in the curvilinear parts of the MDL, but the vectors extracted from this study exactly matched the MDL in the Armistice Agreement Volume II. The measured length is 239.42km(148.77miles). This means that the expression '155mile MDL' or '248km DMZ' in papers, reports or mass media has so far been inappropriate. I think this study will be able to provide information on the exact length of the DMZ in studies related with DMZ or in policy decisions by the national and local government. However, it is deemed necessary to verify this result by national organizations such as the NGII(National Geographic Information Institute). After these verification procedures, I hope that the national government will inform the people of the exact length of DMZ and MDL.

• The Journal of Korean Society for Radiation Therapy
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• v.33
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• pp.71-78
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• 2021

Purpose: To evaluate the inter-fractional position and respiratory reproducibility of lung and liver tumors using pressure conserving type(P-type) abdominal compressor in volumetric modulated arc therapy(VMAT). Materials and methods: Six lung cancer patients and three liver cancer patients who underwent VMAT using a P-type abdominal compressor were included in this study. Cone-beam computed tomography(CBCT) images were acquired before each treatment and compared with planning CT images to evaluate the inter-fractional position reproducibility. The position variation was defined as the difference of position shift values between target matching and bone matching. 4-dimensional cone-beam computed tomography(4D CBCT) images were acquired weekly before treatment and compared with planning 4DCT images to evaluate the inter-fractional respiratory reproducibility. The respiratory variation was calculated by the magnitude of excursions by breathing. Results: The mean ± standard deviation(SD) of overall position variation values, 3D vector in the three translational directions were 1.1 ± 1.4 mm and 4.5 ± 2.8 mm for the lung and liver, respectively. The mean ± SD of respiratory variation values were 0.7 ± 3.4 mm (p = 0.195) in the lung and 3.6 ± 2.6 mm (p < 0.05) in the liver. Conclusion: The use of P-type compressor in lung and liver VMAT was effective for stable control of inter-fractional position and respiratory variation by reproduction of abdominal compression. Appropriate PTV margin must be considered in treatment planning, and image guidance before each treatment are required in order to obtain more stable reproducibility

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.2
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• pp.9-15
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• 2011

In this paper, we propose a method to extract the external oblique muscle of abdomen images that is often excluded by previous method due to image distortion. In the preprocessing phase of the proposed method, we emphasize the brightness contrast with Ends-in search stretching algorithm after removing noise from the initial ultrasonic images. Then we apply average binarization in vertical direction to extract candidate fascia areas. After removing other areas than fascia with morphological characteristics, the lost part in the fascia during the process is restored with such characteristic information and location information. Then the skin area is also removed with information from the arc appearing in convex filming and the candidate muscle areas are extracted by overlapping two results two way up-down search algorithm. Another noise removing process is done to determine the muscle area. In case of obtaining obscure result, after restoring the muscle area by smearing method, the thickness of the muscle is measured by min square method. The experiment verifies that the proposed method is sufficiently effective to analyze the size and shape of muscles in abdomen in ultrasonography than previously used methods.

• Journal of the Korean GEO-environmental Society
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• v.18 no.4
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• pp.5-12
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• 2017

Since 2000, the national geotechnical information DB has been constructed by Transport and Maritime Affairs (present Ministry of Land) and recently, it provides more than 210 thousands borehole informations through the geotechnical information DB portal systems. The initial project of underground space information computerization was begun in 2007, focusing on collecting the informations after then additional studies had been conducted to verify the precision and accuracy of collected informations in 2013~2014. In accordance with the recent initiation of the 3D integrated underground space mapping project, it is necessary to construct 3D image of the geotechnical information and evaluate the accuracy and precision of the information. Therefore, in this research, the basic information regarding the precision of the geotechnical DB is provided by kriging method and analysis of RMSE for the systematic 3D construction of geotechnical information. In addition, the elevation data errors of boring information are verified by analysis of elevation data such as boring information data and DEM data.

• Journal of the Korean Institute of Landscape Architecture
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• v.28 no.6
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• pp.114-126
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• 2001

The purpose of this study is to establish the databases of pollutant sources and water quality measurement data by utilizing GIS, and making the user interface for the management of pollutant sources. Yeongsan Estuarine Lake was formed of a huge levee of 4.35 km constructed by an agricultural reclamation project. Water quality of the reservoir has been degraded gradually, which mainly attributes to increase of point and non-point source pollutant loads from the lake's watershed of 33,374.3 $\textrm{km}^2$ into it. Application of GIS to establishment of the database was researched of pint source such as domestic sewage, industrial wastewater, farm wastes, and fishery wastes, and non-pont source such as residence, rice and upland field, and forest runoffs of the watershed of the lake. NT Acr/Info and ArcView were mainly utilized for the database formation. Land use of the watershed using LANDSAT image data was analyzed for non-point source pollutant load estimation. Pollutant loads from the watershed into the reservoir were calculated using the GIS database and BOD, TN, TP load units of point and non-point sources. Total BOD, TN, TP loads into it reached approximately to 141, 715, 2,094 and 4,743 kg/day respectively. The loads can be used as input parameters for water quality predicting model of it. A user-friendly interface program was developed using Dialog Designer and Avenue Script of AcrView, which can perform spatial analysis of point and non-point sources, calculate pollutant inputs from the sources, update attribute data of them, delete and add point sources, identify locations and volumes of water treatment facilities, and examine water quality data of water sampling points.

• Journal of Korean Ophthalmic Optics Society
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• v.15 no.1
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• pp.19-23
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• 2010

Purpose: The aims of this paper are to assess the competitiveness about the spectacles industry of Korea against Japan. Methods: We use export competitiveness indexes such as market share index, trade specialization index and market comparative advantage index to evaluate the competitiveness of spectacles industry of Korea against Japan. Results: This paper shows that the comparative advantage of the Spectacles industry of Korea in MC(market comparative advantage) against Japan arc spectacles lenses and contact lenses. Furthermore, it can also be known that the spectacles lenses and contact lenses have export competitiveness in the TSI (trade specialization index) against Japan. Conclusions: We need to choose spectacles lenses and contacts lenses as the main export items against Japan in the spectacles industry of Korea. Along with this, we need to improve the image of the Spectacles industry in Korea; after that, we have to create a strategy that would strengthen export competition in other items.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.05a
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• pp.383-386
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• 2006

Several HTPB/AP and HTPB/AP/HMX propellants were investigated experimentally for ignition characteristics in subatmospheric pressure. The threshold ignition pressure was 4psia for HTPB/AP composite propellant. The partial replacement of AP in HTPB/AP composite propellant by $5\sim15%$ of HMX, HNIW showed improvements in the threshold pressure was below 0.4psia. This appears to be due to the exothermic dissociation characteristics of HMX and HNIW at lower temperature $(\sim220^{\circ}C)$ than that of AP. The ignition substance B/KNO3 was coated thinly on the propellant surface for better ignition effect. As a result, ignition delay time of 15% was improved. NC is applied to $B/KNO_3$ ignition substance as a secondary binder and $NC-B/KNO-3$ suspension solution is coated to the propellant surface.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.12
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• pp.6346-6352
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• 2013

Radiotherapy of rectal cancer requires a stabilized image but the movement of patients is almost unavoidable in radiotherapy. In this study, the setup error using the radiation treatment technique was compared according to the loading time and BMI(Body Mass Index) for 14 patients with rectal cancer. In addition, the variation of the dose by the average setup error was compared. Therefore, the technique of a selective standard was established. As a result, 3DCRT(3-Dimensional Radiation Therapy) and VMAT(Volumetric Modulated Arc Therapy) showed a similar time and error. In comparison, IMRT(Intensity Modulated Radiation Therapy) increased the time two fold and the error four fold. In BMI, a more pyknic patient showed a larger error for all techniques. Regarding the dose, IMRT and VMAT increased much more than 3DCRT in the average error at the small bowel. Therefore, 3DCRT of the short time will be applied to pyknic rectal cancer. Moreover, VMAT selects than IMRT in the overexposure of the small bowel.

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.7
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• pp.157-165
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• 1989

To recover three dimensional information in Shape from Texture, the distorting effects of projection must be distinguished from properties of the texture on which the distortion acts. In this paper, we show an approximated maximum likelihood estimation method in which we find surface orientation of the visible surface (hemisphere) in gaussian sphere using local analysis of the texture. In addition, assuming that an orthogonal projection and a circle is an image formation system and a texel (texture element) respectively, we drive the surface orientation from the distribution of variation by means of orthogonal projection of a tangent direction which exists regularly in the arc length of a circle. We present the orientation parameters of textured surface with slant and tilt in gradient space, and also the surface normal of the resulted surface orientationas as needle map. This algorithm is applied to geographic contour (artificially generated chejudo) and synthetic texture.