다중시기 위성자료 기반 낙동강 하구 지역 갯벌 면적 분석을 통한 블루카본 저장량 변화 평가

김민주,박정우,현창욱,Minju Kim,Jeongwoo Park,Chang-Uk Hyun 대한원격탐사학회 2024 大韓遠隔探査學會誌 Vol.40 No.2

Global warming is causing abnormal climates worldwide due to the increase in greenhouse gas concentrations in the atmosphere, negatively affecting ecosystems and humanity. In response, various countries are attempting to reduce greenhouse gas emissions in numerous ways, and interest in blue carbon, carbon absorbed by coastal ecosystems, is increasing. Known to absorb carbon up to 50 times faster than green carbon, blue carbon plays a vital role in responding to climate change. Particularly, the tidal flats of South Korea, one of the world's five largest tidal flats, are valued for their rich biodiversity and exceptional carbon absorption capabilities. While previous studies on blue carbon have focused on the carbon storage and annual carbon absorption rates of tidal flats, there is a lack of research linking tidal flat area changes detected using satellite data to carbon storage. This study applied the direct difference water index to high-resolution satellite data from PlanetScope and RapidEye to analyze the area and changes of the Nakdong River estuary tidal flats over six periods between 2013 and 2023, estimating the carbon storage for each period. The analysis showed that excluding the period in 2013 with a different tidal condition, the tidal flat area changed by up to approximately 5.4% annually, ranging from about 9.38 km² (in 2022) to about 9.89 km² (in 2021), with carbon storage estimated between approximately 30,230.0 Mg C and 31,893.7 Mg C.

VD Pioneer-미국팡 메뉴판닷컴 '저갯 서베이'

김민주,Kim, Min-Ju 벤처기업협회 2008 벤처다이제스트 Vol.118 No.-

VD Pioneer-생체모사에서 배우는 사업 아이디어

김민주,Kim, Min-Ju 벤처기업협회 2008 벤처다이제스트 Vol.116 No.-

VD Pioneer-'블랙삭스닷컴'

김민주,Kim, Min-Ju 벤처기업협회 2008 벤처다이제스트 Vol.115 No.-

'포장은 쓰레기'를 외치는 자연주의 화장품,러쉬(Lush)

김민주,Kim, Min-Ju 벤처기업협회 2008 벤처다이제스트 Vol.122 No.-

의치 연성이장재에 대한 Candida albicans의 부착과 침투연구

김민주,신상완,이정열,Kim Min-Ju,Shin Sang-Wan,Lee Jeong-Yeol 대한치과보철학회 2006 대한치과보철학회지 Vol.44 No.4

Purpose : Colonization of denture soft lining materials by Candida albicans can result in clinical problem, and deterioration of the materials. This study aimed to compare the retention and penetration of C. albicans into four denture soft lining materials commonly used. Materials and methods : Four denture soft lining materials (Coe-comfort$^{(R)}$, Coe-soft$^{(R)}$, GC soft liner$^{(R)}$, and Tissue conditioner$^{(R)}$) discs were prepared to glass slide and dental stone. Adherence of yeast to surfaces was monitored after one hour incubation of standardized washed cell suspension with test disc surfaces. Adherent cells stained with acridine orange were counted fluorescence microscopy. Penetration of yeast into materials bonded with acrylic resin after 1, 2, 3,4, 5, 6 and 7 days incubation was observed through sections stained using acridine orange and estimated to quantitative analysis using radioisotope. Results : There was statistical significance in cell numbers between smooth and rough surfaces(p<0.05). Higher numbers of cells were observed on rough surfaces. There was statistical significance in adherent cell numbers into smooth and rough surfaces individually(p<0.05). According to the increase of incubation periods, the cells penetrated into denture soft lining materials were shown to increase. The differences among all kinds of soft liner were statistically significant(p<0.05),and the largest number of cells penetrated into soft liners was observed in the Coe-soft$^{(R)}$. Conclusion : Initial adherence and penetration of yeast into denture soft lining materials has been influenced by surface roughness and chemical composition of them. The selection of appropriate materials and their fabrication may promote clinical performance.

허약아의 수면 습관에 대한 연구

김민주,이선행,이진용,Kim, Min Joo,Lee, Sun Haeng,Lee, Jin Yong 대한한방소아과학회 2015 대한한방소아과학회지 Vol.29 No.4

Objectives The purpose of this study is to research on sleep habits of weak children groups using objective evaluation tools. Methods This study surveyed 108 children and adolescents of 4~10 years old who visited the department of Pediatrics of ${\bigcirc}{\bigcirc}$ Korean Medicine Hospital from June 19th, 2015 to August 28th, 2015. Weak Children Questionnaire and CSHQ (The Children's Sleep Habits Questionnaire) were used to research on sleep habits of children. We analyzed the data by using PASW Statistics 18.0 with independent t-test. Results CSHQ Score of Weak Children Group was significantly higher than CSHQ Score of Normal Children Group (p<0.05). CSHQ Score ($Mean{\pm}SD$) of Normal Children Group was $52.92{\pm}5.72$ and CSHQ Score ($Mean{\pm}SD$) of Weak Children Group was $56.23{\pm}5.66$. Conclusions Weak Children Group had more sleep habit problems than Normal Children Group.

Megavoltage Cone-Beam CT 영상의 변환을 이용한 선량 계산의 정확성 향상

김민주,조웅,강영남,서태석,Kim, Min-Joo,Cho, Woong,Kang, Young-Nam,Suh, Tae-Suk 한국의학물리학회 2012 의학물리 Vol.23 No.1

적응 방사선 치료(Adaptive Radiation Therapy, ART)를 실행하기 위한 매 치료 마다 획득되는 Megavoltage cone-beam CT (MVCBCT) 영상을 이용한 재 선량 계산 과정은 필수적이다. 본 연구의 목적은 intensity 보정 방법을 적용한 MVCBCT 영상 기반의 선량 계산 결과와 kilo-voltage CT (kV CT) 영상 기반의 선량 계산 결과의 비교 및 MVCBCT 영상 기반의 선량계산 정확성의 향상이다. MVCBCT 영상의 intensity 교정을 위해 kV CT와 MVCBCT을 이용하여 12 종류의 전자밀도 바를 제공하는 Cheese 팬텀 영상을 획득하고, Cheese 팬텀 영상의 동일한 전자밀도 바에서 표현되는 kV CT 영상과 MVCBCT 영상의 intensity 관계를 도출하였다. 이후 kV CT, MVCBCT를 이용한 Rando 팬텀 영상을 획득하여 MVCBCT 영상은 3차원 강체 정합을 수행하였고 본 과정을 통해 MVCBCT 영상은 kV CT 영상과 마치 동일한 모달리티에서 획득한 영상과 같은 위치 및 intensity 분포로 변환되었고, MVCBCT 영상의 잡음을 없애기 위한 Gaussian smoothing 필터를 적용하였다. 위의 과정을 거친 MVCBCT 영상을 토대로 intensity 교정을 적용한 영상과, intensity 교정을 적용하지 않은 영상, kV CT영상을 기반으로 방사선 치료 계획 시스템을 이용한 선량 계산을 시행 하였다. 선량 계산의 결과는 선량 분포의 차이 및 Percentage difference로 평가되었다. Intensity 보정을 적용한 MVCBCT 영상의 선량 계산 결과의 경우 kV CT 영상 기반의 선량 계산 결과와의 Percentage difference가 두경부 영상의 경우 1.08%, 흉부 영상의 경우 2.44%였다. 본 연구에서 적용한 intensity 변환을 통해 MVCBCT 영상을 이용한 선량 계산의 정확성이 향상됨을 확인하였고, 본 연구 방법은 실제 선량 계산에 적용 및 사용의 편리성을 확인하였다. 차후 연구 계획도 본 연구 내용에 의해 제안되었다. The dose re-calculation process using Megavoltage cone-beam CT images is inevitable process to perform the Adaptive Radiation Therapy (ART). The purpose of this study is to improve dose re-calculation accuracy using MVCBCT images by applying intensity calibration method and three dimensional rigid body transform and filtering process. The three dimensional rigid body transform and Gaussian smoothing filtering process to MVCBCT Rando phantom images was applied to reduce image orientation error and the noise of the MVCBCT images. Then, to obtain the predefined modification level for intensity calibration, the cheese phantom images from kilo-voltage CT (kV CT), MVCBCT was acquired. From these cheese phantom images, the calibration table for MVCBCT images was defined from the relationship between Hounsfield Units (HUs) of kV CT and MVCBCT images at the same electron density plugs. The intensity of MVCBCT images from Rando phantom was calibrated using the predefined modification level as discussed above to have the intensity of the kV CT images to make the two images have the same intensity range as if they were obtained from the same modality. Finally, the dose calculation using kV CT, MVCBCT with/without intensity calibration was applied using radiation treatment planning system. As a result, the percentage difference of dose distributions between dose calculation based on kVCT and MVCBCT with intensity calibration was reduced comparing to the percentage difference of dose distribution between dose calculation based on kVCT and MVCBCT without intensity calibration. For head and neck, lung images, the percentage difference between kV CT and non-calibrated MVCBCT images was 1.08%, 2.44%, respectively. In summary, our method has quantitatively improved the accuracy of dose calculation and could be a useful solution to enhance the dose calculation accuracy using MVCBCT images.

자동설계프로그램과 유한요소법을 활용한 래칫 휠 설계에 관한 연구

김민주,이승수,전언찬,Kim, Min-Ju,Lee, Seung-Su,Jeon, Eon-Chan 대한기계학회 2002 大韓機械學會論文集A Vol.26 No.9

This study is to develop a automatic design program of mechanical elements as the integrated system which can create automatically 3-dimensional solid and surface model using visualLISP. By the applying developed system to CAE system, the following objects are realized. At first, constructing the library of automatic design program for unexperienced design engineer, the 3-dimensional modeling of mechanical elements can be obtained easily. at second, the 3-dimensional model for ratchet wheel design is created by finete element model of CAE system and the optimal design condition of key way.

슬립주입에 의한 Y - TZP/Ce-TZP 다층 복합체의 제조(II)

김민주,이윤복,김영우,전병세,박홍채,Kim, Min-Ju,Lee, Yun-Bok,Kim, Yeong-U,Jeon, Byeong-Se,Park, Hong-Chae 한국재료학회 2000 한국재료학회지 Vol.10 No.10

3Y-TZP/12Ce-TZP 의 3층 5층 복합체를 슬립주입법으로 제조하고, 그 기계적 성질을 검토하였다. 지름-원반압축시험법으로 구한 다층복합체의 파괴강도는 327~534MPa이었다. Vickers압입하중의 증가(~300N)와 더불어 압입강도는 전반적으로 감소하였으나, 다층물질은 단상물질에 비하여 우수한 손상저항을 나타내었다. 49N의 하중으로 압입후 다층물질의 4점 꺽임강도는 620~674MPa 인데 반하여 단상 물질의 경우는 129~339MPa을 나타내었다. 압자압입에 의한 다층물질의 인서은 $7.7~13.1\;MPa{\cdot}m^{1/2}$ 정도를 나타내었다. Three- and five-layer 3Y-YZP/12Ce- TZP composites prepared by a slip casting method have been char­acterized in terms of mechanical properties. The fracture strength of mutilayer c$\alpha$nposites determined in a diametral compression test was 327~534 MPa. Although the indentation strength of the materials was generally reduced with i increasing Vickers indentation load up to 300 N, the damage resistance of multilayer composites was superior com­pared to monolithic layer TZP material. The four-point bend strength of the layered material remained at the values of 620~674 MPa after indentation with a load of 49 N, while that of the monolithic TZP material was 129~339 MPa. The microindentation toughness of the multilayer material was $7.7~13.1\;MPa{\cdot}m^{1/2}$.