고결모래의 강도정수 평가

이문주,최성근,이우진,Lee, Hoon-Joo,Choi, Sung-Kun,Lee, Woo-Jin 한국지반공학회 2008 한국지반공학회논문집 Vol.24 No.11

This study proposes the equations evaluating the shear strength of cemented sand by analytical interpretation based on Mohr-Coulomb failure criteria, and verifies them using the results of triaxial and unconfined compression tests. The internal friction angle of cemented sand is identical to that of uncemented one regardless of the stress level, while the cohesion intercept of cemented sand is constant before the breakage of cementation bonds. Therefore, the shear strength of cemented sand can be represented as a summation of the shear strength of uncemented sand and the unconfined compressive strength of cemented sand. In addition, the cohesion intercept of cemented specimen can be expressed as a function of unconfined compressive strength and friction angle. In the transition zone, assuming a constant shear strength, the equations to evaluate shear strength and cohesion intercept of cemented sand are also represented. It is observed that the predicted values using these solutions agree well with the experimental results. The experimental results also show a linear relationship between the unconfined compressive strength and the breaking point of cementation bonds.

반 무한체 위의 사각조각 표면에 작용하는 접선하중에 의한 반 무한체내의 응력 해석

이문주,구영필,조용주,Lee, Mun-Ju,Gu, Yeong-Pil,Jo, Yong-Ju 대한기계학회 2000 大韓機械學會論文集A Vol.24 No.4

The stress field in the body by tangential loading of a rectangular patch on a semi-infinite solid has been solved analytically using potential function. The validity of result of this study was proved by Saint-Venant's principle in the remote region and in the vicinity of the surface with superposition of point loads.

한국에 있어서의 병원사목-어제, 오늘 그리고 내일

이문주,Lee, Mun-Ju 한국가톨릭의료협회 1972 한국가톨릭병원협회지 Vol.3 No.1

병원사목

이문주,Lee, Mun-Ju 한국가톨릭의료협회 1981 한국가톨릭병원협회지 Vol.12 No.-

모자이크 플롯에서 변수와 범주의 순서화

이문주,허명회,Lee, Moon-Joo,Huh, Myung-Hoe 한국통계학회 2008 응용통계연구 Vol.21 No.5

Hartigan과 Kleiner (1981, 1984)에 의해 제안된 모자이크 플롯은 범주형 자료의 탐색에 매우 유용한 시각화 도구이다. 모자이크 플롯은 범주 셀의 빈도를 사각형의 기에 비례하게 나타내므로 이해가 쉽고 데이터에 포함된 정보를 유지하지만 실제 모습은 변수 순서와 변수 내 범주의 순서에 따라 상당히 달라진다. 이에 우리는 본 연구에서 모자이크 플롯에서 크래머(Cramer)의 V 계수를 활용한 변수의 순서화 방법과 감마 계수를 활용한 범주의 순서화 방법을 제안하고 Titanic, Housing, PreSex 등 공개 자료에 적용한 결과를 제시한다. Mosaic plots, proposed by Hartigan and Kleiner (1981, 1984), are very useful in visualizing categorical data. In mosaic plot, multi-way classified cell frequencies are represented by rectangles with proportional area. The plot is easy to understand while preserving the information contained in the data. Plot's appearance, however, does change substantially depending on the order of variables and the orders of categories with variable put into the plot. In this study, we propose the algorithms for ordering variables and categories of the categorical data to be explored via mosaic plots. We demonstrate our methods to three well-known datasets: Titanic, Housing and PreSex.

Zr/Ti 몰비에 따른 PZT-PCNS 압전 세라믹의 압전 및 유전 특성

이시용(S. Y. Lee),이용희(Y. H. Lee),이문주(M. J. Lee),이종섭(J. S. Lee),임기조(K. J. Lim) 대한전기학회 2001 대한전기학회 학술대회 논문집 Vol.2001 No.11

유한요소법을 이용한 동기형 릴럭턴스 전동기의 직접토크제어 특성에 관한 연구

이문주(Moon-Ju Lee),김솔(Sol Kim),이주(Ju Lee),고권민(Kwon-Min Ko),김태덕(Tea-Duk Kim),오상경(Sang-Kyeong Oh) 대한전기학회 2002 대한전기학회 학술대회 논문집 Vol.2002 No.7

오프라인 문자 인식을 위한 칼라 영상 전처리에 관한 연구

이문주(M. J. Lee),전미림(M. L. Jeon),진영근(Y. K. Jin),이은주(E. J. Rhee),김태균(T. K. Kim) 한국정보과학회 1994 한국정보과학회 학술발표논문집 Vol.21 No.1

본 논문에서는 칼라 영상에서 포한된 문자 인식에 필요한 전처리 과정에 관하여 논한다. 칼라 영상에서 문자 영역을 추출하기 위하여 먼저 유사색들을 묶는 clustring을 수행한다. 이는 영상의 입력시 발생하는 또는 영상 고유의 잡영을 제거하기 위한 것이다. clustring된 영상은 이진화의 정확성을 위해 주변분포를 이용하여 대분류한다. 대분류된 영상에서 문자후보 영역을 추출하기 위해서는 intensity 히스토그램 분포에 따라서 전역적 이진화 방법 또는 구조적 이진화 방법이 사용된다. 컴퓨터를 통한 모의실험에서 제안한 알고리즘은 다양한 색을 갖는 칼라 영상에 포함된 문자를 추출하는데 매우 효과적임을 확인할 수 있었다.

구강 편평상피암종에서 CDH-13 유전자의 promoter methylation에 대한 연구

이문주(Moon-Joo Lee),한세진(Se-Jin Han),김경욱(Kyung-Wook Kim) 대한구강악안면외과학회 2008 대한구강악안면외과학회지 Vol.34 No.5

CDH-13(T-cadherin), which is one of a kind among the 20 cadherins, can be found mainly in wall of aorta, neuron, spleen, blood vessel etc. It is also called H-cadherin. This structural difference can explain that CDH-13 is thought to play a key role in maintaining mutual relation between extra and intra-cellular environment rather than in cell adhesion. The main function of CDH-13 is to participate in blood vessel function. Additionally, it is known to regulate cell growth and cell contact inhibition. When cells are proliferating, cell surface perceives other cells so that substance such as CDH-13 can inhibit their growth or proliferation resulting in homeostasis without endless proliferation or invasion of connective tissue boundaries. However, tumor cell itself appears to be different from normal cells’ growth, invasion or transmission. Therefore, it can be diagnosed that these characteristics are closely related to expression of CDH-13 in tumor cells. This study is to investigate expression of CDH-13 in SCC and its correlation with promoter methylation. 20 of tissue species for the study are excised and gathered from 20 patients who are diagnosed as SCC in department of OMS, dental hospital, dankook university. To find development of CDH-13 in each tissue samples, immunohistochemical staining, RT-PCR gene analysis and methylation specific PCR are processed. The results are as follows. 1.Immunohistochemical staining: In normal oral squamous epithelial tissue, strong expression of CDH-13 was found in cell plasma membrane of basal cell layer. On the other hand, in case of low-differentiated oral SCC, development of CDH-13 was hardly seen. 2.The development of CDH-13 gene: In 9 of samples, expression of CDH-13 gene could be seen and 2 of them showed low expression compared to the others. And rest of the 11 samples showed no expression of CDH-13 gene. 3.Methylation of CDH-13 gene: Among 9 samples which expressed CDH-13 gene, 7 of them showed unmethylation. In addition, among 11 samples without CDH-13 gene expression, 10 showed methylation. According to the results stated above, promoter methylation were found in 13 samples(65%) among 20 of oral SCC samples. In low-differentiated SCC, suppression of gene expression could be seen accompanying promoter methylation. These phenomenon of gene expression was proved by immunohistochemical investigation. Finally, for development of oral SCC, conclusions can be made that suppression of CDH-13 played a main role and suppression of gene expression was originated from promoter methylation. Considering this, it is expected that suppression of CDH-13 from promoter methylation to be utilized as a good diagnostic marker of oral SCC.

고결정도와 응력조건에 따른 고결모래의 배수전단거동

이문주(Lee Moon Joo),최성근(Choi Sung Kun),김승한(Kim Seung Han),이우진(Lee Woo Jin) 대한토목학회 2007 대한토목학회논문집 C Vol.27 No.3

본 연구에서는 삼축압축시험을 통해 고결정도와 응력조건에 따른 고결모래의 강도특성과 변형특성을 파악하였다. 동일한 상대밀도의 모래에 대해 석고함유율을 조절하여 시료를 조성한 후, 50~200㎪까지 단계적으로 구속압을 조절하여 배수전단 시험(CID)을 실시하였다. 실험결과에 의하면, 고결정도가 증가할수록 모래의 전단강도가 증가하고 파괴양상이 취성적으로 변하며 전단시 팽창이 크게 발생한다. 동일한 구속압에서 약한 고결모래의 팽창경향은 미고결모래에 비해 현저히 감소하지만, 고결정도가 증가하면 팽창경향이 증가한다. 또한 동일한 고결정도에서 구속압이 증가할수록 전단강도는 증가하지만 구속압에 의한 고결결합 파괴시 거동이 연성적으로 변하며, 고결정도가 큰 시료에서는 큰 구속압에 의해 전단시 압축이 발생한다. 고결결합이 파괴된 이후에 나타나는 극한상태에서는 고결모래의 극한강도 및 유효응력비가 미고결 모래와 유사하며, 고결모래의 점착력은 모두 사라지고 미고결 모래와 동일한 마찰력에 의해 저항한다. 또한 미고결 모래의 변형계수는 구속압 영향을 상대적으로 크게 받는 반면, 고결모래의 변형계수는 결합이 파괴되기 전에는 구속압의 영향이 상대적으로 작았다. 미고결모래와 고결정도가 약한 모래의 할선탄성계수와 전단강도 비는 구속압이 증가할 수록 감소하는 반면, 고결정도가 더 큰 모래의 할선탄성계수와 전단강도 비는 구속압과 함께 증가하는 경향을 보였다. In this study, a series of cm tests were performed on gypsum-cemented specimens to evaluate the strength and the modulus of cemented sand having various degrees of cementation and stress levels. It was shown that, with increasing cementation level, peak shear strength increases; specimen fails in brittle fashion; and the tendency of dilation becomes greater. At the same confining stress level, the dilation of weakly cemented sand is less than that of uncemented sand, whereas the stronger tendency of dilation is observed with increasing degree of cementation. In addition, with increasing confining stress, the shear strength of the specimen increases and a relatively ductile failure is developed once confining pressure causes the bonding breakage. Under high confining stress, volumetric contraction was observed even for strongly cemented sands. When the cementation is completely destroyed, the shear strength and the effective stress ratio of cemented sand converge to those of uncemented sand. Cohesion intercept of the cemented sand disappears after the breakage of cementation bond and intrinsic variables seem to dominate the shear behavior at ultimate state. While Young's modulus of uncemented sand is affected by confining pressure significantly, that of cemented sand is slightly affected until confining pressure breaks the cementation bonds. The ratio of secant Young's modulus and peak strength for uncemented and weakly cemented sands decreases with increasing confining pressure, while that of strongly cemented sand increases with increasing confining pressure level.