• Journal of Korea Water Resources Association
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• v.53 no.12
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• pp.1211-1220
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• 2020

This research detects the features of the bright band (BB) through analysis of the vertical profile of range height indicator (RHI) and the slant range beam profile of plane position indicator (PPI) of the polarimetric radar measurements-horizontal reflectivity (ZH), differential reflectivity (ZDR), and cross-correlation coefficient (ρHV). As a result of the analysis, it is possible to clearly detect the bright band using the polarimetric radar measurements, and it is confirmed that the result is consistent by double searching for the BB using the RHI and PPI scan data at the same time. Based on these results, the accuracy of QPE (quantification of precipitation estimation) can be improved by applying the BB search method by the PPI slant range in this research to large rainfall radars that only scan PPI volumes in the field without RHI observations.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.4
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• pp.777-790
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• 2001

Theoretical analyses have been tried to design high power and stable operating SLD at 1.55${\mu}{\textrm}{m}$ wavelength range which is the lowest absorption wavelength in optical fiber. The materials of active layer and SCH layer were chosen as conventional In1-xGaxAsyPl-y quaternary composition systems. From the transverse mode and the lateral mode analyses of waveguide, the optical power distributions and the optical confinement factor have been studied for single-mode high power operation. According to these analyses, it was calculated the composition and the thickness of SCH layer to obtain the maximum optical confinement factor. In order to obtain low values of the reflectivity, we used the window region and the lateral tilted angle between tile active region and window region. And the reflectivity of SLD was calculated with the gaussian beam approximation and mode analysis. From these researches, it was confirmed for several results to fabricate the efficient and stable SLD. In case of using $1.3\mum$, InGaAsP SCH layer, the layer thickness was obtained $0.08\mum$, to get the maximum optical confinement factor. Using $0.2\mum$, active layer thickness and $0.08\mum$, SCH layer thickness, the window region length is about $100\mum$ without An coating, $10\mum$ in 1% AR coating to obtain about 10-4 reflectivity. When the tilted angle is about $10~15^{\circ}$, the reflectivity is about 10-3. From these results, if the window region length and tilted angle were controlled appropriately in given device structure, it was confirmed that it is possible to fabricate the stable SLD without AR coating analytically.

• Journal of the Korean earth science society
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• v.35 no.2
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• pp.131-146
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• 2014

Multi-beam echosounder data and grain size analysis data of surface sediment were acquired and analyzed in order to investigate the shelf-to-slope morphology, geological character, and their geological controlling factors in the southwestern margin of the Ulleung Basin. According to the morphological character, the continental shelf can be divided into two parts: (1) shallow (~100 m) and steep ($0.5^{\circ}$) inner shelf, (2) deep (100-300 m) and gentle ($0.2^{\circ}$) outer shelf. The continental slope is featured with eight distinct topographic depressions of various spatial dimension (~121 $km^2$ in area) and head wall gradient (${\sim}24.3^{\circ}$). They are developed adjacent to each other and presumably formed by submarine landslides which have recurred under the strong influences of earthquakes and eustatic sea-level change. The inner continental shelf and the continental slope are dominated by fine-grained sediment, whereas the outer continental shelf is dominated by coarse-grained sediment. The surface sediment distribution seems dominantly influenced by eustatic sea-level change. The outer continental shelf is mostly covered by coarse relict sediment deposited during lowstand sea-level, while the inner shelf is covered with recent sediment during highstand sea-level. The surface of the continental slope is covered with fine-grained sediments which were supplied by hemipelagic advection process.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.17-17
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• 2016

이중편파 레이더는 수평 수직반사도($Z_H{\cdot}Z_V$), 차등반사도($Z_{DR}$), 교차상관계수(${\rho}_{HV}$), 차등위상차(${\Phi}_{DP}$) 등 다양한 변수 산출을 통하여 대기 수상체 구분, 우적분포에 영향이 적은 강우량 추정, 밝은 띠(BB, Bright Band)의 탐지 등이 가능하게 됨으로써 수문기상 및 재해관리 분야에 활용성이 점점 더 커지고 있다. 본 연구는 RHI, PPI에서 생산된 레이더 변수를 이용하여 BB를 탐지하고 그 특성을 평가하였다. BB는 레이더를 이용하여 상층대기를 관측할 때 수직단면에서 강수입자가 눈에서 비로 변하는 구간에서 과대하게 높은 반사도가 나타나는 층을 말한다. BB에서는 QPE가 과대 추정되기 때문에, BB의 특성 파악은 레이더의 관측전략 수립과 QPE 보정에 필수적이다. 본 연구에서는 RHI에 의한 $Z_H$의 연직단면분석, RHI와 PPI의 고도각 경사거리(slant range) 빔의 ${\rho}_{HV}$, $Z_{DR}$, $Z_H$에 의한 분석을 통하여 BB의 상단부($BB_{TOP}$), 최정점($BB_{PEAK}$) 및 하단부($BB_{BOTTOM}$)의 고도를 상호 비교 평가하였다. 분석 자료는 KICT X-밴드 레이더에 의한 관측한 2015년 10월 21일의 층상운에 의한 강우를 이용하였다. RHI에 의한 $Z_H$의 연직단면 분석결과 $BB_{top}$, $BB_{bottom}$ 및 $BB_{peak}$는 KICT 레이더 고도(MSL : 40m)를 기준으로 각각 3.26Km, 2.3Km($BB_{width}$: 0.96km) 및 2.7Km로 나타났다. 이 같은 결과는 다른 2가지 분석방법에서도 유사하게 나타나고 있으며, 이는 BB분석을 위해 다양한 변수를 통한 신뢰성 있는 BB의 특성을 파악할 수 있는 기반을 제공한다.

• Progress in Medical Physics
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• v.20 no.3
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• pp.152-158
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• 2009

Total Skin Electron Beam Therapy (TSEBT) of linear accelerator has become use so as to be useful, 2~9 MeV of energy territories came to be used with mycosis fungoides and cutaneous lymphomas in the superficial lesion treatment which covers the major portion of the body. I treat a patient to Stanford technique in this study, and it is $60^{\circ}$ around the patients whom Stanford technique irradiated electronic beam to a linear accelerator in horizontal directions and there is a way a standard of TSEBT treat it to six located field (anterior, posterior, and four obliques) becoming. An each field does horizontally it and consist to beam of the two component which fitted the center to a suitable angle. a patient treats it to three dual field a day in order to make short treatment time. when a first day, we treat one dual field at anterior position and two dual field at posterior position. when the second day, treat one dual field at posterior position and two dual field at anterior position. Therefore, six dual field is finished in perfect periodic two days. we made cylindrical acrylic phantom, and I inserted a dosimeter film between phantom. in order to measure a dose distribution calculation before treat a patient, and a patient checked it in six field directions that got from a treatment. It is after that thermoluminescent dosimetry (TLD) as it uses Rando phantom and then measurement dose distribution in six field directions after attaching at chest, the right and left flank, a back after irradiation.

• Economic and Environmental Geology
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• v.50 no.2
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• pp.129-143
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• 2017

The shallow sediments in the southwestern Ulleung Basin consist of mass flow deposits such as slide/slump and debris flow deposits (DFD), caused by slope failure. These sediments are proven to be important in studying geological disaster and stability of the seafloor. In this paper, we analysised the flow accumulation and slope failure susceptibility of the Ulleung Basin on the basis of multi-beam data, collected in this area. We also studied the distribution pattern and the seismic characteristics of the DFD in the uppermost layer of the Ulleung Basin on the basis of seismic data. The slope susceptibility was calculated as the frequency ratio of each factors including slope, aspect, curvature and stream power index (SPI), which causes the slope failure. These results indicate that the slope failure is frequently to occur in the southern and western continental slope of the Ulleung Basin. The sediment flow (mass flow) caused by the slope failure converges to the north and northwest of the Ulleung Basin. According to the seismic characteristics, the uppermost layer in study area can be divided into four sedimentary unit. These sedimentary units develop from the south and southwest to the north and northwest in association with slope susceptibility and flow accumulation.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.42 no.1
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• pp.1-11
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• 2005

Several Solid Freeform Fabrication Systems(SFFS) are commercialized in a few companies for rapid prototyping. However, they have many technical problems including the limitation of applicable materials. A new method of agile prototyping is required for the recent manufacturing environments of multi-item and small quantity production. The objectives of this paper include the development of a novel method of SFFS, the CAFL/sup VM/(Computer Aided Fabrication of Lamination for Various Material), and the manufacture of the various material samples for the certification of the proposed system and the creation of new application areas. For these objectives, the technologies for a highly accurate robot path control, the optimization of support structure, CAD modeling, adaptive slicing was implemented. However, there is an important problem with the conventional 2D lamination method. That is the inaccuracy of 3D model surface, which is caused by the stair-type surface generated in virtue of vertical 2D cutting. In this paper, We design the new control algorithm that guarantees the constant speed, precise positioning and tangential cutting on the 5DOF SFFS. We develop the tangential cutting algorithm to be controlled with constant speed and successfully implemented in the 5DOF CAFL/sup VM/ system developed in this paper. Finally, this paper confirms its high-performance through the experimental results from the application into CAFL/sup VM/ system.