안구의 비색소성 모양체 상피에서 발생한 유두상 선암종 -1예 보고-

최현주,최영진,이연수,이은정,강석진,김병기,심상인 대한병리학회 1998 Journal of Pathology and Translational Medicine Vol.32 No.12

특발성 좌심실빈맥(Idiopathic Left Ventricular Tachycardia)의 성공적인 전극도자절제술을 위해 단극전기도(Unipolar Electrogram)가 유용한가?

최기준,남기병,강덕현,홍명기,송재관,김재중,박성욱,박승정,박종훈,김유호 대한순환기학회 2000 Korean Circulation Journal Vol.30 No.4

강원대학교 구내림 이용행태에 대한 설문분석

최정기,구소영,조선아,원종현 江原大學校 森林科學硏究所 2003 Journal of Forest Science Vol.19 No.-

본 연구는 강원대학교 학교 숲 이용자들의 행태를 분석하기 위하여 학생, 교수, 행정직원, 외부 방문자를 대상으로 설문조사를 실시하였다. 학교 구내림 필요성에 대한 질문에 대해서 학생이용자는 97%, 교수 이용자는 100%, 행정직원 91%가 필요하다고 응답하였고, 학교구성원의 80%이상이 구내림을 이용하는 것으로 나타났다. 가장 많이 이용하는 구내림 장소로는 학생과 행정직원은 연적지, 교수는 예술대 뒷산으로 조사되었으며, 구내림 이용동기에 대한 질문에는 학교구성원 모두 산책을 위해서라는 답변이 가장 많았다. 구내림 만족도에 대한 설문에서는 학교 구성원 모두 보통수준으로 답하였으며, 체육시설에 대해서는 불만족스럽다라고 응답하였다. 구내림 개선사항으로는 구내림 보존 및 정비, 체육시설확대, 조깅코스개발, 약수 및 연적지 물 관리 등에 대한 의견이 도출되었다. 구내림의 외부 방문자들에 대한 설문에서는 대부분 50세 이상인 퇴직자와 전업주부가 학교 숲을 찾고 있으며, 방문자들은 주로 오전시간에 80%가 찾아오는 것으로 조사되었고, 혼자 방문하는 경우가 70%를 차지하였다. 방문목적은 건강을 위한 산책 및 약수물 이용을 위하여 방문하는 것으로 나타났으며, 가장 많이 이용하는 구내림 장소는 연적지인 것으로 조사되었다. 구내림에 대한 만족도는 대부분 만족하는 것으로 나타났고, 구내림 개선에 대한 사항에는 체육시설 확대가 가장 많았으며 구내림 훼손방지, 산책로 및 벤치시설증대에 대한 요구가 있었다. This study was carried out to investigate the behavioral pattern of student faculty, administration staff, and visitor by questionnaire about campus forest of Kangwon National University. In the question of the necessity of the campus forest, 97% of students, 100% of faculty and 91% of administration staff agreed with the necessity of the campus forest and 80% of university members use the campus forest. The most frequent site of the campus forest was the Yeon-Juk pond for students and administration staff and was the site behind the art building for faculty. The main reason for use of the campus forest was mostly a walk. About the questions dealt with one's satisfaction regarding the campus forest, most members evaluated the average level, and the facilities of physical training were evaluated if the unsatisfied level. The improvements for the campus forest were suggested about conservation of the campus forest, increasing of physical training facilities and the jogging courses, and managing the mineral water and pond. The visitors using the campus forests were mostly retied people or housewives elder than 50 years old. 80% of visitors visits mostly in the morning and 70% of the visitors comes to the campus forest by oneself. The main reasons for use of the campus forest were a walk and dipping the mineral water. The most frequent location was the Yeon-Juk pond for the visitors. Most visitors were strongly satisfied with using of the campus forest. In the questionnaire about improvements of the campus forest, the visitors suggested the increasing of physical training facilities, conservation of the campus forest, and establishing more walking roads and beaches.

노화가 인체 중간엽 줄기세포로부터 조골세포로의 증식 및 분화에 미치는 영향

백기현,태현정,오기원,이원영,조정기,권순용,강무일,차봉연,이광우,손호영,강성구,김춘추 대한내분비학회 2003 Endocrinology and metabolism Vol.18 No.3

연구배경: 일반적으로 골다공증과 연관된 위험인자로는 연령, 폐경, 약물, 불충분한 칼슘섭취, 만성질환 및 운동부족 등이 있는데, 특히 노화가 진행할수록 골밀도가 감소하는 것은 잘 알려져 있다. 노화와 관련하여 진행되는 골소실은 조골세포 및 전구조골세포의 기능적 결핍에 의한 골형성의 감소가 주요한 요인으로 여겨지고 있다. 그 동안 연령이 조골모 세포의 양과 조골모 세포로부터 성숙조골세포로의 분화 및 증식에 미치는 영향에 대한 일부 보고들이 있었으나 아직 일치된 견해는 없는 형편이다. 방법: 다양한 연령의 사람으로부터 골수를 채취, 중간엽 줄기세포가 포함된 단핵세포를 분리한 후 조골세포로 분화하기 좋은 조건하에서 배양하였다. 대상군은다시 젊은군과 노령군으로 구분하여 다양한 변수를 비교 분석하였다. 일차배양에서는 CFU-F를 계수하여 골수내 중간엽 줄기세포의 수를 추산하였고, 칼슘측정을 통하여 기질의 무기화 정도를 비교하였다. 계대배양후 이차배양에서는 시기별로 알카리성 포스파타제 활성도를 측정하고 오스테오칼신 mRNA의 발현을 관찰하여 젊은군과 노령군 사이의 증식능 차이를 비교하였다. 또한 이차배양 시기별로 MTT 측정을 하여 양군간에 증식능 차이가 있는지 알아보았다. 결과: 1. 일차배양 15일째에 평균 CFU-F의 수는 젊은군에서 유의하게 많았다(젊은군 148.3±28.9, 노령군 54.3±9.1, p=0.02). CFU-F의 평균면적은 젊은군에서 넓은 경향을 보였으나 통계적으로 유의하지는 않았다. 2. 일차배양 17일 경과 후 양군간에 기질 칼슘 침착정도는 유의한 차이를 보이지 않았다(젊은군 103.6±50.6, 노령군: 114.0±56.5, p=NS). 3. 이차배양 10일째에 젊은군에서 알카리성 포스파타제 활성도가 고령군에 비해 유의하게 높았다(젊은군: 935.5±115.0 U/mg, 노령군: 578.4±115.7U/mg,p.0.05). 고령군에서는 시간 경과에 따른 변화가 미약했으며 전반적으로 알카리성 포스파타제의 활성도가 젊은군에 비해 낮았다. 4. 이차배양도중 오스테오칼신 mRNA의 발현은 배양시기별로 젊은군에 비해 고령군에서 더 낮은 경향을 관찰할 수 있었다. 5. 이차배양 10일과 15일에 젊은군에서 노령군보다세포증식이 유의하게 증가된 양상을 보였다(10앓 젊은군 0.73±0.05, 노령군 0.58±0.04, p=0.05, 15일; 젊은군 0.80±0.05, 노령군 0.70±0.03, p=0.05).결론: 이상의 연구에서 저자들은 노령군에서 젊은군보다 골수 내 중간엽줄기세포의 수가 적고, 노령군에서 유래한 전구조골세포의 성숙조골세포로의 증식 및 분화가 젊은군 보다 감소해 있는 것을 관찰할 수 있었다. Background: Osteoblasts originate from osteoprogenitor cells in bone marrow stroma, termed mesenchymal stem cells (MSCs) or bone marrow stromal cells. Each MSC forms colonies (colony forming units-fibroblasts [CFL-Fs]) when cultured ex vivo. There are some reports about the age-related changes of the number and osteogenic potential of osteoprogenitor cells, but any relationship has not been clearly established in humans. In this study, we counted MSCs using CFU-Fs count and examined the proliferative capacity and differentiation potential of osteoprogenitor cells. Finally, we analyzed how these parameters varied with donor age. Methods: Bone marrow was obtained from the iliac crest of young (n=6, 27.2±8.6 years old) and old (n= 10, 57.4k6.7 years old) healthy donors. Mononuclear cells, including MSCs, were isolated and cultured in osteogenic medium. In primary culture, we compared the colony-forming efficiency of MSCs between the two groups and determined the matrix calcification. When primary culture showed near confluence, the cells were subcultured. Alkaline phosphatase activity, osteocalcin expression by RT-PCR and proliferative potential by MTT assay were examined by the time course of secondary culture. Results: At the 15th day of primary culture, the mean number of CFU-Fs was significantly higher in the younger donors (young: 148.3±28.9, old: 54.3±9.1, p=0.02) and the mean size of CFL-Fs was also larger in the younger donors than the older donors. However, matrix calcification was not different between the two groups (young: 103.6±50.6, old: 114.0±56.5, p=NS). In secondary culture, alkaline phosphatase activities were significantly lower in the older donors. The younger donors showed peak alkaline phosphatase activity at day 10, while the older donors didn't showed a remarkable peak (young: 935.5±115.OU/mg, old: 578.4±115.7U/mg, p<0.05). Total cell number as a proliferative index increased progressively during the secondary culture and a significantly greater cell number was noted in the younger donors. Osteocalcin expression was generally upregulated in the younger donors, but this was not statistically significant. Conclusion: Our study shows that the number of osteoprogenitor cells is decreased during aging and that the proliferative capacity and differentiation potential of osteoprogenitor cells seem to be reduced during aging (J Kor SOC Endocrinol 18:296-305, 2003).

학교와 학원의 비교를 통해 본 청소년의 플로우 및 내적경험

김기옥,현은자,최인수,유현정 대한가정학회 2004 Human Ecology Research(HER) Vol.42 No.4

The purpose of this study was to compare the school life of Korean high school students between public and proprietary schools, especially focused on their internal experience and flow. Internal experiences were composed of three dimensions: emotion, cognitive efficiency, and satisfaction. Flow was classified into four conditions: apathy, boredom, anxiety, and flow. The study results are: 1. Korean high school students felt more flow when they were in public school than in proprietary school,. In public school, they felt relatively more bored, and on the other hand, they were relatively more anxious in proprietary school. 2. Korean high school students felt more positive emotions when they were in public school than in proprietary school. 3. Korean high school students were more involved into study when they were in public school than in proprietary school. 4. Korean high school students were more satisfied when they were in public school than in proprietary school.

저열팽창성 Fe-29Ni-17Co 코바 합금의 고온균열 발생과 고온연성에 미치는 S 및 Mn의 영향

이기안,박종혁,조봉현,남궁정,김문철 대한금속재료학회 2003 대한금속·재료학회지 Vol.41 No.12

The effect of S & Mn on the hot ductility of Fe-29Ni-17Co Kovar alloy and the mechanism of high temperature cracking occurrence were investigated. It has been found that the brittle intergranular fracture at high temperature cracking is closely associated with the sulfide along grain boundary. Experimental results showed, especially when the S content was high and the Mn content was free, that small cavities could be nucleated easily on FeS particles along grain boundary and propagated fast at high temperature. The hot ductility of Kovar alloy was drastically increased with the addition of Mn and it was also increased with decreasing S content. SEM and FE-SEM analyses showed that the Mn addition in this alloy could cause ductile intergranular fracture appearance below 1150℃ by the precipitation of MnS. It was proposed from the results that the addition of Mn and optimum S content (below 30 ppm) in Kovar alloy was necessary in order to reduce the hot cracking susceptibility.

인터넷 쇼핑경험에서의 소비자만족 형성과정에 관한 연구

유현정,김기옥 대한가정학회 2002 Family and Environment Research Vol.40 No.5

This study aims to examine the forming procedure of consumer satisfaction from Internet shopping experience. Many studies on the satisfaction have primarily focused on the examination of the antecedents of satisfaction along with the expectation-disconfirmation paradigm dominating the former studies. This shady has built an Internet shopping expectation-disconfirmation model as to apply the expectation-disconfirmation model into the condition of the Internet shopping. The summary of study is represented in following. 1. The expectation of risk and performance of benefit had a significantly positive effect on the perceived disconfirmation. In addition, an expectation of benefit and performance of risk had a significantly negative effect on the perceived disconfirmation. 2. A performance of risk and performance of benefit not only had a significantly indirect effect, but also a significantly direct effect on the consumer satisfaction. But expectation of risk and expectation of benefit had no significant direct effect on satisfaction. 3. Not only the perceived disconfirmation had a significant positive effect on satisfaction, but also an effect of the perceived disconfirmation on satisfaction(0.472) is larger than that of the performance of risk or performance of benefit. Meaning that, it is desirable for one to apply the expectation-disconfirmation model into the Internet shopping circumstances as much as the off-line markets.

다중 제어루프에 의한 자기부상용 DC-DC 전원장치에 관한 연구

조주현,조정민,전기영,이상집,이승환,오봉환,이훈구,한경희 明知大學校 産業技術硏究所 2004 産業技術硏究所論文集 Vol.23 No.-

The author present a modified multi-loop algorithm including feedforward for controlling a 55kW step down chopper in the power supply of Maglev. The control law for the duty cycle consists of three terms. The first is the feedforward term which compensates for variations in the input voltage. The second term consists of the difference between the slowly moving inductor current and output current. The third term consists of proportional and integral terms involving the perturbation in the output voltage. This perturvation is derived by subtracting the desired output voltage from the actual output voltage. The proportional and integral action stabilizes the system and minimizes output voltage error. In order to verify the validity of the proposed multi-loop controller, simulation study was tried using Matlab simulink.

Al-Mg-Si合金의 時效擧動에 미치는 加工熱處理의 影響

趙顯麒,李基大,朴定國 慶北大學校 1980 論文集 Vol.30 No.-

Effects of Thermo-Mechanical Treatment(TMT) on ageing behaviours in Al-Mg-Si alloy is investigated by means of tensile test, hardness measurements and transmission electron microscopy. The maximum 0.2% proof stress of the TMT materials in final ageing is higher by 10%∼20% than that of the two-step aged materials. The strength of TMT materials also increases more rapidly than that of two-step aged materials. The maximum 0.2% proof stress of the TMT materials with pre-ageing is higher than that of the TMT materials without pre-ageing. The strength of TMT materials increases with rising pre-ageing temperature, and it decreases with rising final-ageing temperature. Consequently, this type of TMT would have some practical significance in improving the mechanical properties of 6061 alloy.

수종의 치수 처치제가 유견 유구치의 치수조직에 미치는 영향에 관한 조직학적 비교연구

한정현,손일수,김용기 단국대학교 치의학연구소 1992 논문집 Vol.4 No.-

Pulpal reaction to tested medicaments during various time intervals(1, 7, 14, 28, 56 days) were evaluated histologically under light microscope. In Formocroesol-ZOE group, classical 3 different histological zones were observed with apical diffusion of fixation zone, whereas none-to slight diffusion could be found. Only Glutaraldehyde-ZOE group showed active fibrotic replacement. Generalized severe inflammation and internal resorption were observed in Glutaraldehyde-Ca(OH)_2 group and ZOE control group. 5 minute glutaraldehyde (2%) pulpotomy using ZOE as base material showed the best histological picture among all the tested materials.