• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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• pp.90-93
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• 2003

The most common deteriorating processes of concrete structures in the world-wide are carbonation and chloride ion. In this paper, chloride profiles of carbonated concrete is predicted to considering two layer composite model, which is based on Fick's 2nd law. From the experimental result on combined deterioration of chloride and carbonation, it was examined that high chloride concentration was built up to 3-5㎜ over depth from carbonation depth. The analytical modeling of chloride diffusion, which was based on the Fick's 2nd law of diffusion, was suggested to depict the relative influence of the carbonation depth.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.1022-1024
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• 2009

Stereoscopic Images provide depth information with the relative distances between the objects in the images. There are many different ways to extract disparity maps from the visible spectral images. For the infrared spectral range, the same approach cannot be utilized for the innate low resolution and colorless features because typical methods require corresponding features between the images. The authors suggest a new approach that makes use of image segmentation to obtain depth information for stereoscopic millimeter-wave images. For image segmentation a selective visual attention model based on the theory of a feature-integration of attention is used. Experimental results show the proposed method provides reasonable depth information for object shape recognition and display.

• Structural Engineering and Mechanics
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• 제89권3호
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• pp.301-308
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• 2024

Concrete carbonation is a continuous and slow process from the outside to the inside, in which its penetration slows down with the increased depth of carbonation. In this paper, the results of the evaluation of the measurement of concrete carbonation depth using a non-destructive ultrasonic testing method are presented. According to the results, the relative nonlinear parameter caused more sensitivity in carbonation changes compared to Rayleigh's fuzzy velocity. Thus, the acoustic nonlinear parameter is expected to be applied as a quantitative index to recognize carbonation effects. In this research, combo diagrams were developed based on the results of ultrasonic testing and the experiment to determine carbonation depth using a phenolphthalein solution, which could be considered as instructions in the projects involving non-destructive ultrasonic test methods. The minimum and maximum accuracy of this method were 89% and 97%, respectively, which is a reasonable range for operational projects. From the analysis performed, some useful expressions are found by applying the regression analysis for the nonlinearity index and the carbonation penetration depth values as a guideline.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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• pp.525-528
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• 2006

The remote sensing data can be used to calculate the water depth especially in the clear and shallow water area. In this study, the SPOT data was used for bathymetric mapping in Dong-Sha atoll, located in northern South China Sea. The in situ sea depth was collected by echo sounder as well. A global positioning system was employed to locate the accurate sampling points for sea depth. An empirical model between measurement sea depth and band digital count was determined and based on least squares regression analysis. Both non-classification and unsupervised classification were used in this study. The results show that the standard error is less than 0.9m for non-classification. Besides, the 10% error related to the measurement water depth can be satisfied for more than 85% in situ data points. Otherwise, the 10% relative error can reach more than 97%, 69%, and 51% data points at class 4, 5, and 6 respectively if supervised classification is applied. Meanwhile, we also find that the unsupervised classification can get more accuracy to estimate water depth with standard error less than 0.63, 0.93, and 0.68m at class 4, 5, and 6 respectively.

• 대한방사선치료학회지
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• 제31권1호
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• pp.57-65
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• 2019

목 적: 전자선 치료에서 저 용융점 납합금과 순수 납을 이용한 차폐 시 두께증가에 따른 블록 가장자리의 산란선 영향을 알아보고자 한다. 대상 및 방법: $10{\times}10cm^2$ 어플리케이터의 Insert Frame 절반을 차폐하도록 블록을 제작하였고, 두께는 각 재질당 3, 5, 10, 15, 20 (mm)로 하였다. 공통 조건을 에너지 6 MeV, 선량률 300 MU/Min, 갠트리 각도 0, 부여선량 100 MU으로 설정하였고, 블록의 위치와 측정점의 위치, 블록재질을 각각 달리하여 블록 두께증가에 따른 상대적인 산란비율을 평행평판형 전리함과 고체팬텀으로 측정하였다. 결 과: (측정 깊이 / 블록 위치 / 블록 재질)이 (표면 / 어플리케이터 / 순수 납)일 때 블록 두께가 3, 5, 10, 15, 20 (mm) 순으로 증가함에 따라 상대선량은 15.33 nC, 15.28 nC, 15.08 nC, 15.05 nC, 15.07 nC로 측정되었다. (표면 / 어플리케이터 / 합금 납)일 때 15.19 nC, 15.25 nC, 15.15 nC, 14.96 nC, 15.15 nC로 측정되었다. (표면 / 팬텀 위 / 순수 납)일 때 15.62 nC, 15.59 nC, 15.53 nC, 15.48 nC, 15.34 nC로 측정되었다. (표면 / 팬텀 위 / 합금 납)일 때 15.56 nC, 15.55 nC, 15.51 nC, 15.42 nC, 15.39 nC로 측정되었다. (심부 / 어플리케이터 / 순수 납)일 때 16.70 nC, 16.84 nC, 16.72 nC, 16.88 nC, 16.90 nC로 측정되었다. (심부 / 어플리케이터 / 합금 납)일 때 16.83 nC, 17.12 nC, 16.89 nC, 16.77 nC, 16.52 nC로 측정되었다. (심부 / 팬텀 위 / 순수 납)일 때 17.41 nC, 17.45 nC, 17.34 nC, 17.42 nC, 17.25 nC로 측정되었다. (심부 / 팬텀 위 / 합금 납)일 때 17.45 nC, 17.44 nC, 17.47 nC, 17.43 nC, 17.35 nC로 측정되었다. 결 론: 차폐블록을 이용하여 전자선 치료를 진행할 때 블록위치는 환자 체표면보다는 어플리케이터에 삽입하고 두께는 각 사용 에너지에 해당되는 최소 적정차폐두께로 제작해야 한다. 또한 블록 가장자리 경계선으로부터 떨어진 거리에 따라 변화하는 산란선의 영향을 충분히 고려하여 치료를 시행하는 것이 바람직하다고 사료된다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.274-274
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• 2012

In-depth analysis by secondary ion mass spectrometry (SIMS) is very important for the development of electronic devices using multilayered structures, because the quantity and depth distribution of some elements are critical for the electronic properties. Correct determination of the interface locations is critical for the calibration of the depth scale in SIMS depth profiling analysis of multilayer films. However, the interface locations are distorted from real ones by the several effects due to sputtering with energetic ions. In this study, the determination of interface locations in SIMS depth profiling of multilayer films was investigated by Si/Ge and Ti/Si multilayer systems. The original SIMS depth profiles were converted into compositional depth profiles by the relative sensitivity factors (RSF) derived from the atomic compositions of Si-Ge and Si-Ti alloy reference films determined by Rutherford backscattering spectroscopy. The thicknesses of the Si/Ge and Ti/Si multilayer films measured by SIMS depth profiling with various impact energy ion beam were compared with those measured by TEM. There are two methods to determine the interface locations. The one is the feasibility of 50 atomic % definition in SIMS composition depth profiling. And another one is using a distribution of SiGe and SiTi dimer ions. This study showed that the layer thicknesses measured with low energy oxygen and Cs ion beam and, by extension, with method of 50 atomic % definition were well correlated with the real thicknesses determined by TEM.

• 감성과학
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• 제16권1호
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• pp.29-42
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• 2013

본 연구에서는 피사체의 깊이와 깊이 표현의 상세레벨(detail level)을 각기 다르게 조정한 깊이맵을 이용하여 2D-to-3D 입체변환을 수행하고, 변환된 입체 이미지를 기반으로 시청자 평가 실험을 진행하여 피사체의 절대적 깊이 변화와 배경간의 깊이 차이에 따라 깊이맵의 상세레벨이 깊이감, 볼륨감, 불편감에 미치는 효과를 분석하였다. 주객체의 깊이는 3 레벨로 조정하였고, 또한, 주객체와 배경과의 상대적 깊이 차이도 하나의 독립변인으로 분석하기 위하여 3 레벨로 조정하였다. 깊이맵의 깊이 표현의 상세레벨을 다시 3레벨로 나누어, 이들 조건을 만족하는 18개의 깊이맵을 정의하고 이를 기반으로 실험을 위한 입체영상을 생성하였다. 18개의 입체영상을 실험참가자에게 보여 주고 설문을 통하여 각 영상별로 실험자들이 느끼는 주관적 입체감, 볼륨감, 불편감을 조사하였다. 그 결과 주 피사체의 절대적 위치와 피사체-배경간의 상대적 거리차이가 달라짐에 따라 깊이맵의 상세도가 깊이감, 볼륨감, 불편감에 미치는 영향력이 달라지는 결과를 얻었다. 단색 깊이맵의 경우는 주객체의 절대적 깊이위치에 상관없이 전반적으로 볼륨감을 크게 훼손하고, 스크린의 안쪽에 객체가 위치하는 경우, 다른 상세레벨의 깊이맵에 비해 깊이감도 크게 저하시키는 효과를 보이기 때문에 주객체의 절대적 위치와 상관없이 사용을 피하는 것이 바람직 한 것으로 분석되었다. 또한, 세밀한 깊이맵과 간략한 깊이맵을 적용하였을 때 실험자가 입체감을 크게 다르게 느끼지 못하는 것으로 나타남에 따라 입체변환시 모든 장면에 너무 과도하게 상세한 깊이맵을 구성할 필요가 없는 것으로 분석되었다.

• 한국항공우주학회지
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• 제44권1호
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• pp.12-22
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• 2016

달착륙선의 라이다 기반 위험회피 착륙시스템은 기본적으로 목표 착륙지역에 대한 지형 파라미터인 경사와 험준도로 위험도를 계산하고 해당 지역에 대하여 위험도가 최소값을 갖는 점을 안전한 착륙 지점으로 선정한다. 이때, 경사와 험준도만을 고려할 경우 라이다 측정오차에 의해 착륙지가 위험요소 근처로 선정될 수 있으며 이는 착륙선에 위협적이다. 이러한 문제를 해결하고 최대한 안전한 착륙지점을 선정하기 위하여 위험상대거리 기반의 위험도를 기존의 지형파리미터 기반의 위험도와 함께 고려하여야 한다. 본 논문에서는 경사와 험준도 각각에 대한 위험상대거리 기반 위험도가 지형 특성에 따라 착륙지 선정결과에 미치는 영향을 분석하였고, 두 가지 위험상대거리를 동시에 고려하였을 때 가장 좋은 위험회피 착륙 성능을 나타냄을 시뮬레이션과 3차원 뎁스 카메라를 이용한 실험을 통해 확인하였다.

• 대한의용생체공학회:의공학회지
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• 제43권6호
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• pp.409-416
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• 2022

Since the detection of cervical intraepithelial neoplasia (CIN) is increasing due to regular cervical cancer screening, there is a high demand for simpler tools to diagnose and treat CIN in the clinic. In this study, we proposed an electric property of cervical tissue to verify treatment using a laser. At first, we observed the depth and width of ablated cervical tissues for 29 samples according to four different pulse energy of the fractional CO₂ laser to find enough pulse energy to reach the basement layer for initiated CIN. And then, the relative frequency differences in impedance spectrum before and after laser irradiation for ten non-CIN samples were collected using bioimpedance spectroscopy with a multi-electrode probe. As a result, the laser ablated the cervical tissues with a depth of more than 300 ㎛ at 100 mJ pulse energy. Also, we confirmed that the relative changes of electrical property for cervical tissue increased as the pulse energy of laser output increased, and the variation between samples decreased. Since the relative change in electrical properties of cervical tissue can be easily and quickly measured, the proposed technique paves the way for further verification and follow-up study of laser treatment for CIN.

• 한국안전학회지
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• 제23권2호
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• pp.72-80
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• 2008

In a case of an automobile collision, vehicle damage and injury of the driver and the passenger occur. The scale of the collision which is effected by the extent of vehicle damage and the injury of the passenger, depends on the delta-V. Based on the photograph interpretation o the actual case of accidents in the Seoul and the Incheon area, this study measured the depth of crush and calculated the delta-V. Through verifying the correlation of the depth of crush and the change of velocity, relative equation was evaluated and compared with the prior study results to prove that they are almost identical. Thus, the depth of crush can be used as an index of the degree of impact, which can be utilized as the change of velocity to evaluate the level of injury done to the passengers. However, the period of hospitalization and diagnostics claimed by the injured proves to have no correlation with the delta-V and the extent of vehicle damage, this is due to the non-objective way of diagnosis and the anamnesis of the injured. This study established the absolute limit harmlessness and the choosing limit harmlessness, allowing the appraisal for Yes or No of the injury or the harmlessness based on the prior studies. Moreover, utilizing the relative equation formed between the depth of crush and the delta-V, each case of collision was compared and evaluated in comparison to the limit harmlessness to prove that the 90.4% of the so-called 'claiming-to-be-injured' were exaggerating or fabricating.