• 한국도로학회논문집
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• 제5권2호
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• pp.37-47
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• 2003

본 연구는 동결.융해 해석에 대한 역학적 해석에 대한 기초적 연구로서, 미공병단 CRREL에서 개발한 FROST 프로그램을 이용하였다. 국내의 기후조건과 포장단면. 그리고 노상토의 특성을 고려하여 동상특성을 분석하였다. 지하수위는 노상면으로부터 0.35m, 2m, 3.35m 깊이에 위치한 경우를 고려하였다. FROST 해석에 필요한 입력치는 불가피하게 기존의 자료를 이용하였다. 해석결과 시간에 따른 동상량과 동결깊이를 구할 수 있었다. 이러한 관계로부터 구한 최대 동상량은 지하수위가 낮아지면서 감소하는 경향을 나타내고 있다. 최대 동결깊이를 보면 노상은 15cm이내 동결됨을 알 수 있다. 동상에 민감한 흙을 제외하고 국내 노상토는 동결 영향이 크지 않을 것으로 여겨진다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 가을 학술논문 발표대회
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• pp.197-198
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• 2022

Based on the carbonation depth measurement by the indicator for concrete collected from old structures and the quantitative analysis of Ca(OH)₂ and CO₂ in the carbonation section before and after the carbonation depth and in the non-carbonation section, the absorbable CO2 amount and carbonation degree measurement result is as follows 1) The carbonation depth of the 40-year-old reinforced concrete structure was measured to be about 22 mm. (basement interior wall, marble finish, strength 30MPa) 2) The amount of CO₂ absorbed by the concrete was about 4.3% of the sample weight, and the carbonation degree was estimated to be about 53%.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2015년도 하계학술대회
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• pp.452-454
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• 2015

본 논문에서는 다시점 깊이영상 기반 3 차원 영상시스템에서 깊이영상의 해상도에 따른 압축성능을 비교 실험한다. 다시점 깊이영상 시스템에서 깊이영상은 중간시점 합성을 위해 사용되며, 깊이영상은 중간영상의 화질에 큰 영향을 미치게 된다. 본 논문에서는 3 차원 영상시스템에서 깊이영상 해상도에 따른 중간영상의 화질변화를 분석하고, dilation filter 로 인한 성능변화를 비교 분석한다.

• 한국지반공학회지:지반
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• 제5권4호
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• pp.5-16
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• 1989

본 논문은 주택공사의 실내토질시험자료,국립중앙기상대의 기상자료 및 국립건설시험기의 동결 심도 실측자료를 이용하여 우리나라 동결토의 토군 및 동결심도를 유계적으로 분석한 것이다. 이 논과에서 분석한 동결변수는 0.02mm보다가는입경의 비률, 소성지수, 동결지수, 흙의 함수비, 그리고 동결실측심도 등이다. 연구분석한 결과, 우리나라 전역의 동결심도는 지역 보다 흙에 따라 발생하는 차가 매우 큼을 확인하였으며. 1 B 4회 관측한 일평균기단으로 구한 평균 14연간의 최대동결지수를 산정하여 우리나라 57개 도시의 설계동결지수 재포도를 작성 제시하였다. 동결지수와 동결심도와의 관계에 서 산정된 평균직선식을 보정한 t-분포의 99.9% 신뇌상한선을 예상최대동결심도로 실용화 할 수 있는 새로운 기법을 제안하였다.

• 한국임상보건과학회지
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• 제12권1호
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• pp.1654-1659
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• 2024

Purpose: The aim of this study was to determine Correlation analysis of central corneal thickness, anterior chamber volume, and anterior chamber depth in Koreans aged 20 to 24 years using the Pentacam tool. Methods: The subjects of this study were 53 Korean adults with healthy eyes. The central corneal thickness(CCT), anterior chamber volume(ACV), and anterior chamber depth(ACD) was measured with Pentacam device. Data was analyzed by means of the Pearson's correlation cofficient. P-values<0.001 were considered statistically significant. Results: Mean age of subjects was 22.0±2.01 years. The mean +/- central corneal thickness of the right eye and left eye were 546.66±32.221mmg and 545.70±32.759mm, respectively. Also The mean central cornea thickness was 546.19 um in the whole sample. The mean anterior chamber volume the right eye and left eye was 181.66±33.738 mm³ and 180.12±30.84 mm³, respectively. The mean anterior chamber depth was 3.158±0.257 mm and 3.122±0.233 mm in right eye and left eye, respectively. There was a statistically significant difference between anterior camber volume and anterior chamber depth(p<0.001, Pearson's correlation). However there was no statistically significant difference between central cornea thickness and anterior chamber volume. Also there was no statistically significant difference between central cornea thickness and anterior chamber depth. Conclusion: The results of this study could be used as a clinical reference data for diagnosis and treatment of cornea in Korean adolescents.

• 지질공학
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• 제31권2호
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• pp.165-178
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• 2021

자연사면을 대상으로 강우에 따른 침투해석 및 사면안정해석을 통하여 사면토층의 흙-함수특성곡선(SWCC) 맞춤계수에 따른 안정성의 영향을 평가하였다. 연구 대상사면의 토질시료를 채취하여 토층의 물리적, 역학적 및 불포화 특성을 실험하였다. 현장조건의 흙-함수특성곡선(SWCC)의 맞춤계수 α 및 n을 변화시켜 침투해석을 통한 포화심도를 산정하였으며, 이를 고려하여 한계평형해석기법을 이용한 사면안정해석을 수행하였다. 강우에 의한 침투해석 결과에 따르면 맞춤계수 α가 감소함에 따라 토층 내 포화심도가 급격하게 증가하며, 전체 토층에 대한 포화시간도 짧아지는 것으로 나타났다. 그리고 포화심도를 고려한 사면안정해석결과에 의하면 맞춤계수 α가 감소함에 따라 사면안전율은 급격하게 감소하지만, 맞춤계수 n을 증가시키더라도 사면안전율의 변화는 매우 작은 것으로 나타났다. 따라서 강우침투로 인한 포화심도와 이를 고려한 사면안정성은 흙-함수특성곡선(SWCC)의 맞춤계수 α에 크게 영향을 받으며, 맞춤계수 n의 영향은 상대적으로 매우 작음을 알 수 있다.

• Journal of Acupuncture & Meridian Studies
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• 제11권6호
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• pp.355-360
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• 2018

Introductions: Pneumothorax is the most frequent severe acupuncture-related adverse event occurring at the GB 21 acupoint. This study used ultrasonography (US) to measure the depth of the GB 21 acupoint in adults and assessed its applicability for ensuring safe acupuncture practices. Materials and methods: A US probe was used to measure the vertical depth from the skin to the pleural line of the apex of the lungs at the right and left GB 21 acupoints. The sex, age, body weight, height, and body mass index of each person were recorded. Student t test and generalized estimating equations were used for statistical analysis. Results: Sixty women and 41 men with a median age of 29 years were included in this study. The depth of GB 21 increased with body weight, height, and body mass index (p < 0.001). The mean depth of GB 21 in men (17.4 mm) was greater than that in women (14.6 mm; p < 0.001). The depth difference between the right and left shoulders was significant in men (p < 0.001) but not in women. Conclusions: US can be used to measure GB 21 acupoint depth. Further control studies on its use to ensure safe clinical practices, including preventing acupuncture-related pneumothorax, are warranted.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1999년도 춘계학술대회논문집
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• pp.40-44
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• 1999

A finite element analysis has been performed to investigate the effect of die clearance on shear planes in the fine blanking of a part of automobile safety belt. For the analysis S45$^{\circ}C$ is selected as an material which is used in manufacturing the part of automobile safety belt and Cockcroft-Latham fracture criterion is applied, Effect of die clearance on die-roll width die-roll depth burnish zone and fracture zone has been concentrately investigated in the finite element analysis. From the analytical results it has been found that die-roll width and depth of the shear plane increase with increasing die clearance. And the burnish zone has been concentrately investigated in the finite element analysis. From the analytical results it has been found that die-roll width and depth of the shear plane increase with increasing die clearance. and the burnish zone decreases with increasing die clearance but the variation of fracture zone is opposite to that of burnish zone because the increase in die clearance requires less fracture energy Theoretical predictions are compared with experimental results, There is a good agreement between theory and experiment

• 드라이브 ㆍ 컨트롤
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• 제17권4호
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• pp.125-132
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• 2020

The objective of this study was to analyze the axle load of a rice transplanter when planting rice seedlings at different working load conditions to select a suitable gear stage and a constant planting depth for rice seedlings. In this study, there are four levels of planting distances (26, 35, 43, and 80 cm) and three planting depths (low, medium, and high) with two gear stages (1.3 and 1.7 m/s). Axle loads and required planting pressures were analyzed statistically. It was observed that axle torques were increased with increasing planting depths for both gear stages, meaning that axle torques were directly proportional to planting depths for both gear stages. It was also observed that required planting pressures had a significant difference between planting distances. Planting pressures also showed significant difference according to gear stage and planting depth. These results indicate that planting pressures were directly proportional to both gear stage and planting depth. Results revealed that the automatic depth control system of a rice transplanter could not guarantee a constant planting depth as supplied pressures were variable. This indicates that a control algorithm is needed to ensure a constant planting depth. In the future, a control algorithm will be developed for an automatic depth control system of a rice transplanter to improve its comprehensive performance and efficiency.

• 한국기계가공학회지
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• 제7권1호
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• pp.62-66
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• 2008

Machine parts subjected to fluctuating or cyclic loads induce repeated stresses that often result in failure by fatigue. In such cases, the fatigue failures unfortunately sometimes occur. These may arise from a lack of knowledge with regard to the design, fabrication and operation of the machines or structures. The failure analysis provides valuable information regarding the prevention of similar failures. Furthermore, this information will be useful to improve or to develop new products. Failure stress analysis is classified into X-ray fractography. X-ray fractography has the limited applications because of material crystal size, difficult measurement method, electrolytic polishing precision, and long test time. Therefore, this study proposed the new method to improve the measurement precision of plastic zone depth and test time using TRIZ.