• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 학술대회 논문집 정보 및 제어부문
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• pp.273-275
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• 2005

Active thermography is being used since several years for remote non-destructive testing. It provides thermal images for remote detection and imaging of damages. Also, it is based on propagation and reflection of thermal waves which are launched from the surface into the inspected component by absorption of modulated radiation. For energy deposition, it use external heat sources (e.g., halogen lamp or convective heating) or internal heat generation (e.g., microwaves, eddy current, or elastic wave). Among the external heat sources, the ultrasound is generally used for energy deposition because of defect selective heating up. The heat source generating a thermal wave is provided by the defect itself due to the attenuation of amplitude modulated ultrasound. A defect causes locally enhanced losses and consequently selective heating up. Therefore amplitude modulation of the injected ultrasonic wave turns a defect into a thermal wave transmitter whose signal is detected at the surface by thermal infrared camera. This way ultrasound thermography(UT) allows for selective defect detection which enhances the probability of defect detection in the presence of complicated intact structures. In this paper the applicability of UT for fast defect detection is described. Examples are presented showing the detection of defects in PCB material. Measurements were performed on various kinds of typical defects in PCB materials (both Cu metal and non-metal epoxy). The obtained thermal image reveals area of defect in row of thick epoxy material and PCB.

• 상하수도학회지
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• 제32권6호
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• pp.517-526
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• 2018

Climate adaptation strategies for water utilities including 16 water treatment plants(WTPs) in Jeju were investigated. Drought, heat wave, and heavy rain were among the most significant climate factors affecting water utilities in Jeju. Heat wave increases water temperature, which in turn increases the concentration of algae, color, and odor materials. Some adaption strategies for the heat wave can be strengthening water monitoring and introducing advanced water treatments. Heavy rain increases raw water turbidity in surface water. The 7 WTPs that take raw water from streams or springs had a maximum turbidity of less than 50 NTU under heavy rain. However, due to concerns of turbidity spike in treated water, some WTPs discontinued intaking raw water when raw water turbidity increased more than 2 NTU. They instead received treated water from other WTPs which took groundwater for water supply. This happens because of the low skills of employees. Thus, there needs to be an increase in operator competency and upgrade of water facilities for the adaption of heavy rain. To improve adaption for the drought, there should be an increase in the capacity of intake facilities of surface water as well as a decrease in water loss. In addition, water consumption per person should be decreased.

• 대한한의진단학회지
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• 제19권2호
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• pp.91-100
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• 2015

Objectives The aim of this study is to develop a structured clinical protocol related with acquisition of radial pulse wave in the randomized, $2{\times}2$ cross-over design, and cold-heat intervention trial for a pilot and preliminary study. Methods The protocol was contrived based on wide ranging literature searches for cold-heat intervention experiments and radial pulse diagnoses. Results Sample size of 60 subjects was calculated based on an effect size derived from the previous study designed to detect the pre-post cold-heat differences in the radial pulse. Each subjects will be randomly assigned to the cold (first) to heat (last) group (n=30) or heat (first) to cold (last) group (n=30). All subjects will fill out a case report form and questionnaires related with pattern identification, dietary patterns, sleep quality, and physical activity will be surveyed and used as a secondary outcomes. Safety assessment will be reported at the final stage. Conclusions This protocol will provide an additional reference to future studies related with observation of radial pulse during any interventions and also expect to be used as a guideline for acquisition of reliable radial pulse wave data.

• 한국태양에너지학회 논문집
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• 제36권4호
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• pp.1-9
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• 2016

The purpose of this study was to compare heat shading performance of various blind types in summer. 4 types of blinds were employed and the results are summarized as follows: 1) There were significant differences in indoor thermal environment and heat shading performance between different heat shading devices, and functional blinds demonstrated relatively superior heat shading performance. 2) Indoor long wave radiation influx measures were lowest for the coating roll blind (Blind B), followed by the coating venetian blind (Blind C), the venetian blind (Blind A), the roll blind, and not having any blinds at all. 3) Such examination results carry implications to reduce cooling load and enhance the indoor environment.

• 한국지리정보학회지
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• 제23권3호
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• pp.68-84
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• 2020

본 연구에서는 경상남도 창원시를 대상으로 노인인구 분포지역의 공간적 특성과 폭염과의 관계를 분석하였다. 이를 위해 통계청의 인구센서스 자료와 환경부 토지피복도, Landsat 8 지표면온도, 기상청의 폭염일수 자료를 활용하였다. 노인인구 분포의 공간적 특성은 토지이용특성을 고려하여 K-mean 군집화 분석을 통해 총 5개 유형으로 분류하였다. 공간유형별 노인인구 특성은 도시화된 유형(cluster-3)에서 노인인구의 수가 많았으나, 농촌지역과 산림지역에 분포하는 유형(cluster-1, cluster-2)에서는 노인인구의 구성 비율이 높은 것으로 나타났다. 지표면온도와 폭염일수 특성에서는 도시지역에서 지표면온도가 가장 높았으나 폭염일수는 농촌지역이 가장 많았다. 노인인구 분포지역의 공간유형에 따른 폭염 특성을 분석한 결과, 농촌지역 면적이 많은 cluster-2가 15.95일로 가장 높았고, 도시화된 유형인 cluster-3은 9.41일로 가장 낮았다. 즉, 도시지역에 거주하는 노인인구보다 농촌지역에 거주하는 노인인구가 폭염에 더욱 노출되어 있으며, 피해가 가중될 것으로 예상된다. 본 연구의 결과는 여름철 폭염 취약지역의 효과적인 관리와 사전 예방을 위한 다양한 정책방안을 마련하는데 기초적인 자료로 활용될 수 있을 것이다.

• Restorative Dentistry and Endodontics
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• 제32권6호
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• pp.491-497
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• 2007

이 연구의 목적은 continuous wave of obturation technique으로 근관 충전을 할 때, 다양한 heat source plugger의 깊이에 따른 근단부 근관 폐쇄능력을 비교하는 것이었다. 직선 형태 발거 소구치를 #35/.06 크기까지 니켈티타늄 파일을 사용하여 성형 및 세정하였다. 성형과 세정이 완료된 치아를 heat source plugger의 적용 깊이에 따라 15개씩 5군으로 분류하였다. 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 양성 대조군을 제외한 모든 근관은 E&Q plus(Meta Biomed Co., Chungju, Korea)를 사용하여 #35/.06 gutta-percha cone으로 충전하였다. 모든 치아의 근첨공 주변 1 mm를 제외하고 nail varnish를 도포하였고 음성 대조군은 근첨공을 포함하여 전체 면을 도포하였다. 모든 시편을 1% 메틸렌블루 용액에 72시간 동안 보관한 다음 치근첨으로부터 1, 2, 3 mm 높이에서 수평으로 절단하였다. 각 단면을 $12.5{\times}2.5$배 현미경하에서 관찰하고 디지털 카메라로 촬영하였다. 염색제 누출 평가를 위해 aye-degree scoring system을 사용하였다. 각 절단면에서의 점수를 모두 합하여 한 시편의 점수로 사용하고 통계학적 분석을 하였다. 이 실험 조건하에서, 3-7 mm까지의 heat source plugger의 적용 깊이는 근단부 폐쇄에서 유의한 차이를 나타내지 않았다. 5-7 mm의 Buchanan's protocol을 포함한 3-7 mm를 모두 임상 적용에서 받아들여질 만하다고 보인다.

• 대한원격탐사학회지
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• 제36권5_4호
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• pp.1153-1166
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• 2020

본 연구는 위성영상 기반의 열 분포도 및 폭염을 심화시키는 요인 간의 공간적 상관성을 분석하여 열 집중지역과 향후 폭염 위험이 증가할 수 있는 공간의 탐색을 목적으로 수행되었다. 열 집중지역과 폭염 심화요인의 인구, 토지이용, 건축물 각각의 전역적 Moran's I는 높게 나타나 특정 공간에 집중하는 것으로 나타났다. 국지적 Moran's I 분석 결과로, 열 집중지역은 수도권 및 광역시 등 대도시에서 주로 나타났고 상대적으로 온도가 낮은 지역은 산림지역이 우세한 강원도 및 경상북도, 소백산맥 지역에서 집중적으로 나타났다. 인구증가율이 높은 지역은 서울 주변의 경기도, 대전, 부산 인근지역에서 군집 분포하였으며 토지이용과 건축물은 수도권과 대도시에 집중하는 유사한 공간 패턴을 보였다. Bivariate Local Moran's I 분석결과는 열이 집중된 지역에서 인구증가율이 높고, 인공적·도시적 건축환경 및 토지이용이 이루어지는 것으로 나타났다. 본 연구결과는 열 집중지역의 순위를 도출할 수 있으며 전국적으로 열이 집중되고 이를 심화시킬 수 있는 환경을 가진 지역을 탐색할 수 있으므로 궁극적으로 선제적 폭염 대응대책 수립에 기여할 수 있을 것이다.

• 대한기계학회논문집B
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• 제26권2호
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• pp.318-327
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• 2002

In this paper, heat transfer and pressure oscillation characteristics on oscillating capillary tube heat pipe(OCHP) according to input heat flux, mixture ratio of working fluid and inclination angle were investigated and were compared single working fluid(R-142b) with binary mixture working fluid(R-142b-Ethano1). OCHP was made to serpentine structure of loop type with 10 turns by drilling the channels of length 220mm, width 1.5mm, and depth 1.5mm on the surface of brass plate. In this study, R-l42b and R-l42b-Ethanol were used as working fluids, the charging ratio of working fluids was 40(vol.%), the input heat flux to evaporating section was changed from 0.3W/㎠ to 1.8W/㎠, and mixture ratio of working fluid was R(100%), R(95%)-E(5%), R(90%)-E(10%), and R(85%)-E(15%). From the experimental results, it was found that the effective thermal conductivity of single working fluid was better than that of binary mixture working fluid. But, in case of binary mixture working fluid, critical heat flux was higher than that of single working fluid. And, the higher the mixture ratios of working fluid, the lower heat transfer performance. In case of pressure oscillation, as the inclination angle was lower, pressure wave was more irregular. These phenomena were more serious when the working fluid was binary mixture. Besides, when mixture ratio was higher, saturated pressure was increased, more irregular wave was observed and the mean amplitude was increased. For the same input heat flux, inclination angle and charging ratio, when pressure oscillation has sinusoidal wave, mean amplitude was small, and saturated pressure was low value, the heat transfer was excellent.

• 패션비즈니스
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• 제12권6호
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• pp.1-10
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• 2008

Public interest in healthy hairs gets growing as damaged hairs are seen more frequently with the generalization of heat permanent waves. For this study, experiments have been conducted to understand the influences on the changes in physical and morphological features of wave forms and damaged hairs, by collecting virgin hairs from the women in their mid-20's, who had not experienced chemical applications, and by dividing the applications of heat perm hair treatments, PPT(for pre-treatment) and LPP(for post-treatment), into the pre-treatment, the post-treatment, the pre & post-treatment, and the non-treatment. For the wave formations, curl waves were investigated by the bare eyes using the pictures taken by a digital camera. For the comparison of physical features, the experiments of tensile strength and elongation were done and their mean values were found. For the observations of morphological features, the pictures were taken by SEM for comparison. As for the findings, regarding the curl wave shapes of hairs, the most even and elastic S curl was formed in the case of non-treatment. In the physical features, both of the tensile strength and elongation showed a decreasing tendency in line with the hair damage levels, and the case of the pre & post-treatment indicated the tendency most similar to the control group. In the morphological features of the cuticle, observed with an SEM, the pre-treatment showed the higher possibility of reducing the cuticle damages than the post-treatment did. LPP was found to play the role of protective membrane for the post-treatment, and the pre & post-treatment turned out to reduce most effectively the cuticle damages.

• Journal of Mechanical Science and Technology
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• 제18권9호
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• pp.1630-1639
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• 2004

The present paper investigated the correlation between the acoustic pressure variations and the augmentation of heat transfer in the ultrasonic induced acoustic fields. The augmentation ratios of heat transfer coefficient were experimentally measured and were compared with the profile of the pressure distribution in the acoustic fields predicted by numerical analysis. For numerical analysis, a coupled finite element-boundary element method (coupled FE-BEM) was applied. The results of the present study reveal that the acoustic pressure is higher near two ultrasonic transducers than other points where no ultrasonic transducer was installed. The augmentation trend of heat transfer is similar with the profile of the acoustic pressure distribution. In other words, as the acoustic pressure increases, the higher augmentation ratio of heat transfer is obtained. Numerical and experimental studies clearly show that the acoustic pressure variations are closely related to the augmentation of heat transfer in the acoustic fields.