• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.869-872
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• 2003

The thermal contamination of the Younggwang coastal marine ecosystem has been investigated using space borne thermal infrared data acquired over the period 1985-2003 by the Landsat and NOAA satellites. The analysis of AVHRR data brought out the general pattern and extension of thermal plume while TM data yielded more accurate information about the plume shape, dimension, dispersion direction etc. The examination of sea surface temperature (SST) computed from these images clearly indicates that the thermal plume extends 70 to100km southward during summer and 50 to70km northwestward during winter monsoons. The maximum plume temperature was 29$^{\circ}C$ in summer and 12$^{\circ}C$ in winter. The comparative analysis shows that the temperature retrieved from TM is slightly higher (1.8$^{\circ}C$, 3$^{\circ}C$ and 2.2$^{\circ}C$ for the images of 98/11/10, 99/05/05 and 99/05/21 respectively) than those derived from AVHRR data. The correlation coefficient between the TM-derived SST and AVHRR-derived SST was 0.72.

• 터널과지하공간
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• 제8권4호
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• pp.261-274
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• 1998

이 연구에는 가축성 강재지보에 대한 실내실험 및 현장실험 결과가 제시된다. 시험지보는 단위중량이 25.8kg/m인 Gloken profile U 빔 3매를 조립하여 제작되었다. 양단이 힌지로 지지되는 반원형 및 아치형 지보에 대한 정역학적인 해석이 실시되었다. 실험된 U빔의 형상계수는 1.35이었고 지보형태에 따른 2차 소성힌지의 위치를 산정하였다. 천장부에서 단일집중하중을 받는 아치형 지보의 내하력을 조사하여 이를 지보 각주 길이의 함수로 나타내었다. U 빔 연결부의 결합토크를 변화시키는 실물크기 지보시험을 수행하여 시험지보의 가축특성을 파악하였으며, 결합토크를 설계하는 방법을 연구하였다. 결합토크가 21kg.m 인 시험지보를 현장에 설치하고 계측한 결과 전형적인 가축현상을 관찰할 수 있었다.

• 터널과지하공간
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• 제18권4호
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• pp.272-279
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• 2008

본 연구에서는 폐광산으로 인한 광산재해 중 기간 및 일반 시설물이나 인명의 피해를 초래하는 지반침하의 예측 및 평가를 위하여 국내에서 비교적 용이하게 확보할 수 있는 정보인 갱도심도를 사용하여 단순하면서도 국내 지질 및 채굴조건에 적합한 지반침하위험도 평가법을 개발하였다. 개발된 방법을 가상의 규칙적인 채굴적과 실제 침하현장에 대하여 적용한 결과 기존의 영향함수법에 의한 결과 및 현장 침하 사례와 유사한 결과를 얻었다. 따라서 본 연구에서 개발한 평가법은 복잡한 지질구조와 불규칙한 채굴적으로 대표되는 국내광산의 지반침하위험도평가 및 예측에 효과적으로 사용할 수 있을 것을 판단된다.

• 한국산업융합학회 논문집
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• 제20권2호
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• pp.133-140
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• 2017

This paper is a study of the central structural unit model of the sandwich core structure. The applied model is based on the honeycomb structure formed by the truss, the H-shaped honeycomb structure formed by adding the truss of H shape to the space of the center portion, and the honeycomb structure formed by the plate. Applied material property is AISI 304 stainless steel, which has cost effectiveness and easy to get near place. The truss diameter of the model is three different type: 1mm, 2mm and 3mm. ABAQUS software is obtained to do the analysis and applied test is quasi-static loading. Boundary conditions for the analysis are that vertical direction loading at top place without any rotation and bottom surface is fixed. The test results show that the H-truss model has the highest stiffness and yield strength. Therefore, it is hoped that more and more researching for the development of a unit model in sandwich core structure has been investigating and that the developed sandwich core model can be applied into various industrial fields such as mechanical or aerospace industries.

• 한국표면공학회지
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• 제40권4호
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• pp.197-202
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• 2007

Fit of the restoration and its cementation procedure is crucial to both its short and long term prognosis. Marginal fit is affected by many variables during the fabrication process. These variables, being intrinsic properties of the materials or the clinical technique used, can cause changes in the size and shape of the definitive restoration. Even if all variables are controlled carefully, the seating of a restoration can still be affected due to insufficient space for the luting agent. The use of die spacer can reduce the elevation of a cast restoration of a prepared tooth, decreased seating time, improve the outflow of excess cement, and lower the seating forces. The purpose of this study was to evaluate the marginal fidelity according to die spacer application times and measurement site. Casting alloys were prepared and fabricated using non-precious metal at $950^{\circ}C$. Specimens are divided into four groups: I(die spacer painted casting for wax pattern), II(die spacer non painted casting for wax pattern). The specimens were cut and polished for marginal gap observation. The marginal gap was observed using scanning electron microscopy (SEM).

• 한국정보통신학회논문지
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• 제12권1호
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• pp.196-204
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• 2008

이 논문에서는 정면 얼굴 영상을 대상으로 사상체질 판정에 사용되는 얼굴 인상을 효과적으로 판정하는 방법을 제안하였다. 판정을 위하여 눈, 턱 형 태 등에 대한 특징을 정의하고 사용하였다. 주성분 분석법을 이용하여 주어진 특징 데이터의 차원을 축소하여 표현하고, 특징 벡터 사이의 클래스 분리를 최대로 하는 선형 변환인 선형 판별 분석법을 수행한 후 SVM을 이용하여 8가지 종류의 인상을 판정하였다. 여러 얼굴 영상에 대해 실험한 결과, 전문가인 한의사가 판정한 결과를 기준으로 약 85.3% 정확도를 가지는 판정결과를 얻었다.

• 한국의류학회지
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• 제43권5호
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• pp.742-752
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• 2019

This study analyzes the type of subjectivity of married women who have experienced pregnancy and childbirth. It also provides basic data on clothing development that can provide satisfaction to the physical comfort and appearance of pregnant women by understanding the conditions necessary for maternity wear design. This study used Q methodology. The type of recognition for maternity wear was classified into three types and explained 90.88% of total variance. Type 1 was comfort and activities style-oriented. They preferred the A-line shape with a size adjustable style and elastic material. In addition, they preferred designs using details such as wrinkles. Type 2 was a fitted body and modern style-oriented. It was analyzed that they prefer a pants style that is close to the body in a simple and modern style of monotone. Type 3 held a lot of space and was cute style-oriented. They preferred cute dress style along with a maternity suit that could cover the hip and abdomen. Maternity wear design is necessary to develop various designs considering preferences because it is classified into types that emphasize comfort, types that emphasize modernity that is close to the body, and styles that emhasize cute styles.

• Structural Engineering and Mechanics
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• 제10권6호
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• pp.517-532
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• 2000

A direct output feedback control scheme was recently proposed by the authors for single-story building structures resting on flexible soil body. In this paper, the control scheme is extended to mitigate the seismic responses of multi-story buildings. Soil-structure interaction is taken into account in two parts: input at the soil-structure interface/foundation and control algorithm. The former reflects the effect on ground motions and is monitored in real time with accelerometers at foundation. The latter includes the effect on the dynamic characteristics of structures, which is formulated by modifying the classical linear quadratic regulator based on the fundamental mode shape of the soil-structure system. Numerical result on the study of a $\frac{1}{4}$-scale three-story structure, supported by a viscoelastic half-space of soil mass, have demonstrated that the proposed algorithm is robust and very effective in suppressing the earthquake-induced vibration in building structures even supported on a flexible soil mass. Parametric studies are performed to understand how soil damping and flexibility affect the effectiveness of active tendon control. The selection of weighting matrix and effect of soil property uncertainty are investigated in detail for practical applications.

• Current Optics and Photonics
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• 제5권5호
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• pp.576-582
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• 2021

Dichroic beam-splitter (DBS) with polarization-maintaining took an important role in the free space quantum telecommunication tests on the Micius satellite of China. In this presentation, we designed and prepared a 50 layer polarization-maintaining DBS coating by a dual ion beam sputtering deposition (Dual-IBS) method. In order to solve a stress problem, an 18 layer special anti-reflection (AR) coating with similar physical thickness ratio was deposited on the backside. By stress compensation, the surface flatness RMS value of the DBS sample decreased from 0.341 λ (@632.8 nm) to 0.103 λ while beam splitting and polarization maintaining properties were almost kept unchanged. Further, we discussed the mechanism of film stress and stress compensation by equation deduction and found that total stress had a strong relationship with the total physical thickness and the ratio of layer materials.

• Steel and Composite Structures
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• 제32권5호
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• pp.671-686
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• 2019

Active control of solar panels with honeycomb core and carbon nanotube reinforced composite (CNTRC) facesheets for smart structures using piezoelectric patch sensor and actuator to reduce the amplitude of vibration is a lack of the previous study and it is the novelty of this research. Of active control elements are piezoelectric patches which act as sensors and actuators in many systems. Their low power consumption is worth mentioning. Thus, deriving a simple and efficient model of piezoelectric patch's elastic, electrical, and elastoelectric properties would be of much significance. In the present study, first, to reduce vibrations in composite plates reinforced by carbon nanotubes, motion equations were obtained by the extended rule of mixture. Second, to simulate the equations of the system, up to 36 mode shape vectors were considered so that the stress strain behavior of the panel and extent of displacement are thoroughly evaluated. Then, to have a more acceptable analysis, the effects of external disturbances (Aerodynamic forces) and lumped mass are investigated on the stability of the system. Finally, elastoelectric effects are examined in piezoelectric patches. The results of the present research can be used for micro-vibration suppression in satellites such as solar panels, space telescopes, and interferometers and also to optimize active control panel for various applications.