위암 환자에서 절제된 림프절 수의 차이와 관련이 있는 인자

정귀애,박정희,변익건,김경종,장정환,김권천,민영돈 朝鮮大學校 附設 醫學硏究所 2004 The Medical Journal of Chosun University Vol.29 No.1

Purpose: By the definition of UICC TNM classification (fifth edition), the nodal stage of gastric cancer is based on the number of metastatic lymph nodes, which is influenced by the number of resected lymph nodes. And individual differences in the number of resected lymph nodes had been observed in patients with gastric cancer. The aim of this study is to verify the factors which are associated with the difference in the number of resected lymph nodes in patients with gastric cancer. Methods: We reviewed 613 patients with gastric cancer who underwent curative resection and D2 lymph node dissection with 15 or more resected lymph nodes. The number of resected lymph nodes was analyzed according to the characteristics of patients, the types of operation and prognostic factors of gastric cancer. Results: The mean number of resected lymph nodes per patient was 33.0 (median: 31.0, range: 15-88). The number of resected lymph nodes was significantly associated with the types of operation, the location and size of tumor, macroscopic types, depth of tumor invasion and the number of metastatic lymph nodes. Patient's age, gender and the histopathological finding's had no relationship with the number of resected lymph nodes. Conclusions: The number of resected lymph nodes from gastric cancer was different in each patient despite of same D2 lymph node dissection and it was associated with several prognostic factors of gastric cancer.

鈴木 治의 作品에 관한 硏究

원경환,조수정 홍익대학교 산업디자인 연구소 2002 미술디자인 논문집 Vol.- No.7

자기평가 활동이 초등학생의 말하기 능력에 미치는 영향

이경은,김정환 한국교원대학교교육연구원 2006 敎員敎育 Vol.22 No.3

본 연구는 자기평가 활동이 초등학생의 말하기 능력에 미치는 영향을 검증하기 위해 첫째, 자기평가 활동이 학생들의 말하기 능력에 어떠한 영향을 미치는가? 둘째, 자기평가 활동이 학생들의 말하기 능력 수준별로 어떠한 차이를 보이는가? 라는 연구문제를 설정하였다. 이 연구문제를 해결하기 위하여 K시 소재 4학년 2개 학급 62명을 실험집단과 통제집단으로 선정하였다. 실험 처치는 본 연구자가 4주간 8회기에 걸쳐 실시하였다. 실험에 투입한 자기평가 도구는 자기점검식 평정방법과 학습 일지 방법을 혼합하여 본 연구자가 제작하였다. 본 연구에서 사용된 말하기 능력 측정 도구로는 말하기 능력 4가지 하위요소에 대해 3점 척도의 자기점검 평정표로 제작한 자기평가지로 동일하게 사용하였다. 말하기 능력은 교사 채점자 3인이 말하기 내용선정, 말하기 내용조직, 표현 및 전달, 자신감 있게 말하는 태도의 각 요소에 대하여 3점 척도의 분석적 평가를 한 후 그 결과를 평균하였다. 말하기 능력은 실험 전인 사전검사와 8회기 자기평가를 적용한 정보를 전달하는 말하기 실험 후의 사후검사, 그리고 4주 후의 지연검사를 통해 측정되었다. 연구에서 얻어진 결과는 첫째, 자기평가 활동이 학생들의 말하기 능력을 향상시켰으나 지속적인 효과는 나타나지 않았다. 둘째, 자기평가는 말하기 능력 상, 중, 하위 집단간 비교에서 상위집단의 말하기 능력을 향상시켰으나 지속적인 효과는 나타나지 않았다. 따라서 본 연구는 자기평가 활동이 장기적으로 이루어진다면 학생들의 수행능력을 향상시킬 수 있는 바람직한 교육적 대안이 될 수 있를 것이다. The purpose of this research was to investigate effects of self-assessment on speaking ability for elementary school students. The research question were as follows ; (1) Self-assessment affect speaking ability? (2) Self-assessment show the difference according to the level of speaking ability? Nonequivalent control group pretest-posttest design was used for this research. Sixty two 4th grade children(actually two classes) were selected for performing experiment. One group was the self-assessment group(n=31) and the other was the control group(n=31). These treatments administered 8 times for 4 weeks in the classroom situation. It took for 40 minutes to complete each experiments. The used instruments were speaking ability test which was scored by three teacher assessors. Means and standard deviations obtained from these tests were analysed with Independent Samples t-test, One-way ANCOVA, MANOVA, MANCOVA. On the basis of the findings of the present study, the following conclusions were made: (1) Self-assessment was effective for the improvement of speaking ability. But the effect of self-assessment did not continue. (2) Self-assessment showed the signifiant difference in accordance with the level of speaking ability. The self-assessment improved speaking ability more positively in high level class than medium level class and low level class. But the effect of self-assessment in high level class did not continue. Consequently, Self-assessment made positive influences on increasing speaking ability. But it is required for improving speaking ability to need the more time training.

活性슬럿지法에 의한 炭化水素 함유 廢水의 淨化

고정삼,김재하,강경수,고영환 濟州大學校工科大學附屬産業技術硏究所 1991 尖端技術硏究所論文集 Vol.2 No.-

Activated sludge process which has been widely applied to the treatment of waste-water was slightly modified to remove hydrocarbons from wastewater. The process of wastewater treatment consisted of two consecutive reactors. Cells of Acinetobacter calcoaceticus were first cultivated in synthetic wastewater containing 3%(W/V) of hydrocarbons. The resulting culture was then exposed to acclimatized active sludge. Hydrocarbon concentrations of the effluent from the process were 0.19-0.21%(W/V). The contents of suspended solid were reduced to 17-53 ㎎/l. The data imply that A.calcoaceticus can be used for the treatment of wastewater containing hydrocarbons.

셀레콕시브 및 그 합성유도체들의 항암활성 스크리닝

박정란,강진형,구효정,노지영,류형철,박상욱,고동현,조일환,이주영,황다니엘,김인경 한국약제학회 2003 Journal of Pharmaceutical Investigation Vol.33 No.2

Selective COX (cyclooxygenase)-2 inhibitors including celecoxib have been shown to induce apoptosis and cell cycle changes in various tumor cells. New inhibitors are recently being developed as chemomodulating agents. We evaluated celecoxib and screened 150 synthetic compounds for anti-proliferative activities in vitro. Effects of celecoxib on COX activity, cell growth, cell cycle distribution, and apoptosis induction were determined in A549 COX-2 overexpressing human non-small cell lung cancer (NSCLC) cells. The COX inhibition of celecoxib increased with concentration up to 82% at 1μM after 24 hr exposure. Forty μM and 50μM of celecoxib induce G_1 arrest, and TUNEL-positive apoptotic cells, respectively. Among 150 compounds, several compounds were selected for having greater COX-2 inhibitory activity and higher selectivity than celecoxib with growth inhibitory activity. Celecoxib showed concentration-dependent COX inhibitory activity, and ability to induce cell cycle arrest and apoptosis in human NSCLC cells in vitro. Among synthetic analogues screened, several compounds showed promising in vitro activity as COX-2 inhibitory anticancer agents, which warrant further evaluation in vitro and in vivo.

여천공단 주변의 삼림식생 구조와 토양환경

이혜정,이정환,오경환 경상대학교 환경보전연구소 1995 環境保全硏究所報 Vol.3 No.1

대기오염이 삼림식생의 구조와 토양환경에 미치는 영향을 규명하기 위하여 여천공업단지 및 그 주변지역의 삼림에서 1992년 5월부터 1993년 8월까지 식물상, 삼림식생구조, 토양환경, 토양환경과 삼림식생 구조와의 관계 등을 조사하였다. 1. 조사지역에서 출현하는 관속식물은 55과 107속 125 종 16 변종 2 품종으로 총 143 종류가 출현하였으며, 우점종은 곰솔 (Pinus thunbergii)이었다. 2. 삼림 군집구조는 오염원에 가까울수록 교목층이 빈약하고 하층식생이 단순하였으며, 오염원에서 멀리 떨어진 대조구에서는 층위구조가 뚜렷하고 하층식생이 잘 발달되어 있었다. 3. 종다양성지수는 1.266~1.796으로서 오염원에 가까운 지역일수록 낮았고, 오염원에서 가장 멀리 떨어진 대조구에서 가장 높았으며, 출현종수는 종다양성지수와 양의 상관관계를 나타내었다. 4. 중요치는 곰솔이 12.2로 가장 높았고 졸참나무 (Quercus serata) 11.2, 때죽나무 (Styrax japonica) 10.4, 사스레피나무 (Eurya japonica) 9.3, 청미래덩굴 (Smilax china) 9.1등의 순이었다. 5. 층별 주요종의 중요치 변화를 보면, 교목층에서는 종다양성지수가 낮으 s지역으로 갈수록 소나무 (Pinus densifora)가 출현하지 않았고 참나무류 (Quercus spp.)는 전체 조사지소에서 다소 높은 중요치를 나타내었다. 관목층에서는 떠ㅐ죽나무가 종다양성지수가 가장 낮은 지역에서 현저하게 높은 중요치를 나타내었으며, 사스레피나무와 청미래덩굴은 대부분의 조사지소에서 중요치가 고르게 나타났다. 초본층에서는 미국자리공 (Phytolacca americana)과 댕댕이덩굴(Cocculus tribulus)이 종다양성지수가 낮은 지역에서 중요치가 증가하였다. 6. 조사지소별 중요치의 분석결과에 의하면 소나무는 대기오염에 민감하고, 참나무류와 사스레피나무는 중간 정도이며, 때죽나무, 미국자리공, 댕댕이덩굴 등은 내성이 있는 것으로 사료되었다. 7. 조사지역의 토양환경은 pH 4.15~5.08, 전기전도도 52.0~138.0 ㎛ho·cm^-1, 유기물량 3.8~14.6%, 총질소량 0.05~0.28%, 유효인량 0.05~0.29mg·100g^-1, 유효황량 88~335ppm 등으로 각각 나타났다. 오염원에 인접한 조사지소 1에서는 pH 4.15, 전기전도도 138.㎛ho·cm^-1, 유효황량 294ppm 등이었고, 대조구로 선정된 조사지소 9에서는 pH 5.08, 전기전도도 52.7㎛ho·cm^-1, 유효황량 88ppm 등으로 나타나 많은 차이가 있었다. 9. 토양 환경요인과 삼림식생 구조와의 관계에서, 대기 중의 아황산가스의 농도가 높아질수록 토양의 유효황량이 증가하였고, 토양의 유효황량은 출현종수 및 종다양성지수와 각각 음의 상관관계를 나타내었다. Flora, vegetation structure of forest, soil environment, and the correlation between soil environment and vegetation structure were investigated in the vicinity of Yeocheon Industrial Complex, Yeocheon-city, Choˇllanam-do in Korea from May 1992 to August 1993 with a view to reveal the influences of air pollution to the vegetation structure and soil. The flora of the study area was composed of 55 families, 107 genera, 125 species, 16 varieties and 2 forma or total 143 taxa of tracheophytes and dominant species was Pinus thunbergii. The species diversity indices (H') were lower near the pollution sources, and highest in the control site. The number of species was positively correlated with the species diversity indices. The importance value (I.V.) of Pinus thunbergii was highest as 12.3, and those of Quercus serrata, Styrax japonica, Eurya japonica and Smilax china were 11.0, 10.4, 9.3 and 9.1, respectively. In tree layer, Pinus densiflora was not distributed in the area which has lower species diversity indices, and Quercus spp. has rather high I.V. in all sites. In shrub layer, Styrax japonica showed remarkably high I.V. in area which has the lowest species diversity indices and Eurya japonica, Smilax china hold even I.V. in most of the sites. In herb layer, Phytolacca americana and Cocculus trilobus was increased in area which had low species diversity indices. According to the comparison with the importance values in each site, Pinus densifora was considered as sensitive to the air pollution, but Quercus spp. and Eurya japonica as intermediate, and Styrax japonica, Phytolacca americana and Cocculus trilobus as tolerant. As the result of the correlation analysis among soil environmental factors, pH showed the negative correlation with all the soil factors. The available sulfur showed the negative correlation with total nitrogen and available phosphorus. As the result of the correlation analysis among soil environmental factors and vegetation structure of forest, the available sulfur of soil incresed as concentration of SO₂ in the atmosphere was higher, and the available sulfur of soil were negatively correlated with the number of species and the species diversity indices.

이종접합재 접합 계면근방 균열의 응력 및 파괴특성

오정국,차용훈,오환섭,박준건,박경식 朝鮮大學校 機械技術硏究所 1998 機械技術硏究 Vol.1 No.1

현재까지 이종마찰압접재의 강도측정은 실험 (7)-(15)에 의해 구해져 왔다. 하지만 최근 이종마찰압접재의 효율성을 인정하여 여러 실용 부품에 응용하려는 연구가 한창 진행중이다. 이종마찰압접재에 대한 저자들(1)-(6)의 기초실험결과 일반적인 단종재와는 상이한 파괴거동(3)이 관찰되었고, 파괴역학적인 관점에서 정성적인 data 확보가 필요하게 되었다. 따라서 본 연구에서는 인장시험시 이종마찰압접재의 접합강도와 미소균열들에 의한 파괴거동을 파괴역학적 관점에서 해석적으로 고찰하여 보고자 경계요소법(BEM ; Boundary Element Method)을 이용하여 접합계면을 포함하는 접합부를 중심으로 계면상의 응력분포와 계면의 중앙에 결함이 균열로써 존재하는 경우의 응력분포와 인장시험시 열영향부에서 관찰된 균열의 모델링을 통한 균열선단에서의 응력해석을 행하였고, 그 결과 얻어진 중요한 내용을 요약하면 다음과 같다. 계면의 중앙에 균열이 존재하는 접합계면의 표면부에서 응력의 특이성이 발생하며 탄성계수의 비가 증가할수록 특이성이 증가함이 관찰되었다. 탄성계수의 비가 일정한 경우 균열의 크기가 변화하여도 계면의 표면부에서 발생하는 특이성은 거의 같은 값을 갖게 되며, 탄성계수의 비가 증가할수록 표면부의 응력 특이성의 크기는 증가한다. 이종마찰압접재의 인장시험시 관찰된 균열을 모델링 하여 해석한 결과 최대 응력 기준으로 살펴볼 때 인접한 균열선단에서의 응력분포는 균열을 합체시키는 방향으로 작용함을 알 수 있다. In this study stress distribution on the interface and stress near tip of the sub-interface crack in the dissimilar friction welded material is analyzed by using of BEM( Boundary Element Method). Stress singularity near surface of model to analyze is observed for various crack length and ratio of elastic modulus. Tensile and shear stress distribution near two neithbor sub-interface crack tips are analyzed. Existance of singularity near surface on the interface is particular situation so that we need to investigate for dissimilar friction welded materials by means of numerical analysis method.

퍼지알고리즘를 이용한 유도전동기 속도제어에 관한 연구

조정민,전기영,함년근,이승환,이훈구,한경희 명지대학교 대학원 1999 대학원논문집 Vol.3 No.-

The conventional PI controller are fragile in parameter variation and load-variation. Therefore, in this paper, a speed control algorithm based on the Fuzzy PI controller is proposed for the high performance speed control of a voltage ?? inverter to drive 3-phase induction motors. The computer simulation and experiment results show that the proposed controller are more excellent control characteristics than conventional PI controller in transient-state and steady-state response.

활성슬럿지법에 의한 탄화수소 함유 폐수의 정화

고영환,강경수,김재하,고정삼 濟州大學校 工科大學 産業技術硏究所 1991 産業技術硏究報告 Vol.2 No.-

Activated sludge process which has been widely applied t o the treatment of waste-water was slightly modified to remove hydrocarbons from wastewater. The process of wastewater treatment consisted of two consecutive reactors. Cells of Acinetobacter calcoaceticus were first cultivated in synthetic wastewater containing 3% (W/V) of hydrocarbons. The resulting culture was then exposed to acclimatized active sludge. Hydrocarbon concentrations of the effluent from the process were 0.19-0.21% (W/V). The contents of suspended solid were reduced to 17-53 ㎎/l. The data imply that A. calcoaceticus can be used for the treatment of wastewater containing hydrocarbons.

인공 치아우식 발생 모델에서 디지털 방사선 공제술을 이용한 인접면 치아우식증의 진단

박정훈,최용석,황의환,이기자,최삼진,박영호,김경숙,진현석,홍경원,오범석,박헌국 대한구강악안면방사선학회 2009 Imaging Science in Dentistry Vol.39 No.1

Purpose : The purpose of the experiment was to evaluating the diagnostic ability of dental caries detection using digital subtraction in the artificial caries activity model. Materials and Methods : Digital radiographies of five teeth with 8 proximal surfaces were obtained by CCD sensor (Kodak RVG 6100 using a size #2). The digital radiographic images and subtraction images from artificial proximal caries were examined and interpreted. In this study, we proposed novel caries detection method which could diagnose the dental proximal caries from single digital radiographic image. Results : In artificial caries activity model, the range of lesional depth was 572-1,374 μm and the range of lesional area was 36.95-138.52mm². The lesional depth and the area were significantly increased with demineralization time (p<0.001). Furthermore, the proximal caries detection using digital subtraction radiography showed high detection rate compared to the proximal caries examination using simple digital radiograph. Conclusion : The results demonstrated that the digital subtraction radiography from single radiographic image of artificial caries was highly efficient in the detection of dental caries compared to the data from simple digital radiograph.