폐도자기를 골재로 이용한 콘크리트의 특성

강성구,이완조,황인동,박성,정윤중,Kang, Sung-Gu,Lee, Wan-Jo,Hwang, In-Dong,Park, Sung,Chung, Yun-Joong 한국세라믹학회 2005 한국세라믹학회지 Vol.42 No.2

Nowadays, large amount of waste pottery and porcelain annually are produced. It is needed that they are used as recycled materials in order to prevent environmental pollution and gain economic profits. Therefore, the purpose of this study is to present the method of utilizing the recycled aggregates that are obtained from waste pottery and porcelain as the concrete aggregate. The qualities of the recycled aggregate were compared with those of the crushed aggregate through measuring their physical properties. The test results showed that the replacement of crushed aggregate by recycled aggregate at the levels $10\%,\;20\%$, and $30\%$ had little effect on the compressive strength of the concretes, but higher levels of replacement reduced the compressive strength. Increment of the replacement of recycled aggregate caused increase in absorption ratio. As a conclusion, norman strength recycled aggregate concretes can be produced using less than $30\%$ of recycled aggregate. 현재 국내에서 많은 양의 도자기 폐기물이 발생하고 있으며, 이들 폐기물은 경제적 이득과 환경 보전의 차원에서 재활용하는 방안이 모색되어져야 한다. 따라서, 본 연구에서는 도자기 폐기물을 콘크리트용 골재로 이용하여 폐도자기의 재활용성을 검증하고자 하였다. 폐도자기 재활용 골재(recycled aggregate)의 품질을 부순 골재(crushed aggregate)와 비교 분석하였으며, 부순 골재 단독 콘크리트와 재활용 골재가 비례대로 치환된 콘크리트의 물리적 특성을 비교 분석하였다. 실험 결과 재활용 폐도자기의 비율이 $10\%,\;20\%$, 그리고 $30\%$까지는 압축강도에 작은 영향을 미쳤지만, 재활용 폐도자기의 비율이 $30\%$ 이상 증가할수록 압축강도는 급격히 감소하였으며, 홉수율은 증가하였다. 실험 결과에 따르면, 일정한 압축강도를 지니는 폐도자기 재활용 콘크리트의 제조를 위해서 대체 가능한 재활용 골재의 최대 함량은 $30\%$임을 확인 할 수 있었다.

자동열차운전장치를 이용한 도시철도 신호설비의 개량방안에 관한 연구

강성구(Sung-Gu Kang),최승호(Seung-Ho Choi),조봉관(Bong-Kwan Cho) 한국철도학회 2003 한국철도학회 학술발표대회논문집 Vol.- No.-

The national subway went under construction in 1971, and after three years of endeavor, Seoul subway line number one opened for traffic in 1974. Line number two went under construction in 1978 and it opened for traffic in 1984. With the use of safety operation for more than 20 years, the life cycle nearly carne to an end. Therefore the improvements for the safety operation are unavoidable. The total system should not be affected when the new and conventional systems are overlapped, the system operation is in the initial stage, and it confronts the situation of abnormal operation. However, there is a total lack of experience in construction and improvement for the trains that are in the use of large transport and density headway. In this paper, we propose an improvement method of the subway signalling system using ATO (Automatic Train Operation control scheme) to which the latest Digital ATC is applied, and examine the first application model of ATO system.

1치환 하이드로퀴논의 치환방향이 열굴절 폴리에스테르의 전이온도에 미치는 영향

강성구(sung-gu Kang),이진식(Jin-sik Lee) 한국산업융합학회 2002 한국산업융합학회 논문집 Vol.5 No.2

Because of the difference of the relative reactivity between two hydroxyl groups of the hydroquinone due to the steric hindrance of the substituent, many combinations of the substituent direction in the polyesters derived from asymmetrical diphenols such as monosubstituted hydroquinones was expected. It was studied how the mode of the direction affected the properties of the resulting polyesters in terns of the transition temperatures of the thermotropic polyesters prepared from terephthalic acid, 2,4-dichloroterephthalic acid, and phenylhydroquinone by the reaction using p-Toluenesulfonylchloride in pyridine. The direction was tried to control the relative reactivity by changing the reaction temperature and addition time of the hydroquinone, and by modifying it through an association of the hydroquinones with DMF.<br/>

고강도용 폴리카르본산계 고성능 감수제가 사용된 콘크리트의 성능

이완조,강성구,황인동,이재용,박성,정윤중,Lee, Wan-Jo,Kang, Sung-Gu,Hwang, In-Dong,Lee, Jae-Yong,Park, Sung,Chug, Yun-Joong 한국세라믹학회 2005 한국세라믹학회지 Vol.42 No.3

최근 국내에 소개된 폴리카르본산계의 종류는 기능적 분류로 감수용, 유지용, 초고강도용 등으로 소개되고 있으며 이들은 각기 화학적 구조의 차이와 시멘트와 혼합 후 거동의 차이에 의하여 각기 다른 물리적 특성을 보였으며 감수용의 경우 시멘트 중량의 $1.2\%의 사용시 $30\% 이상의 높은 감수율을 보였으나 골재분리를 동반하였으며 콘크리트 제조 후 45분 경과시 슬럼프 플로우의 감소가 약 30cm 이상 발생하였으며 유지용의 경우 롱일 사용량에서 약 $25\% 감수율을 보였으며 45분까지의 슬림프 플로우의 경시 변화는 15cm 이하로 관찰되었다. 초고강도용의 경우 시멘트 중량의 $1.2\%를 사용한 경우 $30\% 이상의 감수율로 관찰되었으며 슬럼프 플로우의 45분 후의 경시변화는 100m 이하로 측정되었다. 압축갔도의 경우 초고강도용의 경우 탁월한 조기 강도 증진 효과를 보였으며 특정배합에서의 18시간 압축강도는 약 $60\;Kgf/cm^2$ 이상이 확보될 수 있었으며 24시간에서 $80\;Kgf/cm^2$이상이 확보될 수 있었다. There are many kinds of polycarboxylate superplasticizer as a functional classification which are introduced to domestic; Water Reducer, Retention, Ultra High Strength Superplasicizer. These are showed different physical behaviors because of the difference in the chemical system and the manners after cement mixing. In the case of water reducer, when $1.2\% of cement weight used, water reducing which is over $30\% is observed, but it take with segregation and the reduction of slump flow shows over 30 cm after 45 min of concrete produce. In the case of retention, when the same quantity used, water reducing which is about $25\% is observed and slump flow which is up to 45 min shows under 15 cm. And in the case of ultra high strength, when $1.2\% of cement weight used, water reducing which is over $30\% is observed, and slump flow which is up to 45 min recorded fewer than 15 cm. Compressive strength of ultra high strength superplasticizer has take effect of early age strength, and in the condition of specific mixing, 18 h-compressive strength is insured for more than $60\;Kgf/cm^2$ and 24 h-compressive strength is insured for more than $80\;Kgf/cm^2$.

위암에서 $PPAR-{\gamma}$ 발현의 임상적 의의

조동희,강성구,박상수,윤진,김일명,윤성민,이윤경,이용직,양대현,조익행,신동규,Cho, Dong-Hui,Kang, Sung-Gu,Park, Sang-Su,Yoon, Jin,Kim, Il-Myung,Yoon, Seong-Min,Lee, Yun-Kyung,Lee, Yong-Jik,Yang, Dae-Hyun,Cho, Ik-Hang,Shin, Dong-Gue 대한위암학회 2006 대한위암학회지 Vol.6 No.4

목적: 최근 Peroxisome-proliferator-activated receptors (PPAR) 의 역할에 대한 관심이 고조되고 있으나 위암에 대한 실제 임상연구는 부족한 실정이다. 이에 저자들은 위암 조직에서의 $PPAR-{\gamma}$의 발현율과 임상적 의의에 대해 분석을 시행하였다. 대상 및 방법: 2001년 1월부터 2005년 12월까지 서울의료원에서 위암으로 근치적수술을 시행 받은 128명을 대상으로 하였다. 적출된 위조직으로 만들어진 파라핀 블록을 이용해 위암조직 125예와 위암주변 정상조직 128예를 채취하여 $PPAR-{\gamma}$ 발현을 면역조직화학염색으로 확인한 후 비교 분석하였다. 결과: 대상 환자의 평균 연령은 61세였으며 남자 84명 (65.6%), 여자 44명(34.4%)으로 1.9 : 1이었다. $PPAR-{\gamma}$ 발현의 양성률은 정상조직 73/128명(57.0%)에 비하여 위암조직에서는 104/128명(81.3%)으로 유의하게 높았다(P<0.001). 위암조직의 분화도에 따른 $PPAR-{\gamma}$ 발현의 차이에서 분화도가 양호한 경우의 양성률(87.0%)에 비해 나쁜 경우 발현율(74.6%)이 낮았으나 통계적 유의성은 없었다(P=0.074). 위암조직에서와 $PPAR-{\gamma}$ 발현 유무와 생존율 사이에 통계적 유의성은 없었으나(P=0.377) 정상조직에서 $PPAR-{\gamma}$의 발현은 단변량 분석에서 유의하게 높은 생존율을 보였다(P=0.003). 5년 생존율과 연관지어 다변량 분석 통계에서 의미가 있었던 것은 UICC TNM 병기뿐이었다(P<0.001). TNM 병기별 5년 생존율은 IA-89.9%, IB-90.0%, II-89.7%, IIIA-41.0%, IIIB-25.9%, IV-14.6% 였다. 결론: 위암조직에서 정상조직에 비하여 $PPAR-{\gamma}$ 발현이 유의하게 높았으며 위암조직의 분화도가 좋을수록 발현율이 높았다. $PPAR-{\gamma}$의 정상조직 내 발현이 단변량 분석상 유의한 생존율 향상이 있었지만 다변량 분석에서는 유의성이 없어 향후 이에 대한 좀더 많은 증례로 유의성을 찾는 연구가 필요할 것으로 생각된다. Purpose: Recently, interest in peroxisome-proliferator-activated receptors (PPAR) has increased, although clinical studies of the effect of $PPAR-{\gamma}$ expression on gastric cancer have not been reported yet. In this study, we investigated the role of $PPAR-{\gamma}$ expression in gastric cancer patients. Materials and Methods: One hundred twenty-eight (128) samples of both gastric cancer and normal tissues were obtained from 128 patients who had undergone at a curative gastrectomy at Seoul Medical Center from Jan. 2001 to Dec. 2005. $PPAR-{\gamma}$ expression was determined by using immunohistochemical staining, and the results were analyzed. The statistical analysis was based on clinicopathological findings and the differences in survival rates. Results: The mean age of the patients was 6n, and the male : female ratio was 1.9 : 1. $PPAR-{\gamma}$ expression was significantly higher in cancer tissues than in normal tissue (81.3% vs. 57.0%, p<0.001). There was insignificant difference between well and moderately differentiated types and poorly differentiated types in terms of the expression of $PPAR-{\gamma}$ (87.0% vs. 74.6%, P=0.074). In the univariate analysis the survival rate was significantly increased when $PPAR-{\gamma}$ was expressed in normal tissue (P=0.003). In the multivariate analysis, only the UICC TNM staging had significance related to the survival rate. Conclusion: The rate of $PPAR-{\gamma}$ expression was higher in cancer tissue than it was in normal tissue from gastric cancer patients. In the univariate analysis, $PPAR-{\gamma}$ expression in normal tissue had significance with respect to survival, but the multivariate analysis showed no such significance. Thus, we should further evaluate more cases to determine whether or not such a significance exists.

양방향 스위치를 이용한 H-bridge 구조의 새로운 멀티레벨 인버터

이상혁(Sang-Hyeok Lee),강성구(Seong-Gu Kang),이태원(Tae-Won Lee),허민호(Min-Ho Hur),박성준(Sung-Jun Park) 전력전자학회 2012 전력전자학회 논문지 Vol.17 No.4

위 분문부에 발생한 원발성 흑색종

박종익,강성구,박상수,윤진,김일명,신동규,Park, Jong-Ik,Kang, Sung-Gu,Park, Sang-Su,Yoon, Jin,Kim, Il-Myung,Shin, Dong-Gue 대한위암학회 2006 대한위암학회지 Vol.6 No.3

Melanoma is a malignant neoplasm of melanocytes most frequently arising from the skin, but primary melanoma can also arise from the mucosa of the gastrointestinal tract. Gastrointestinal melanomas are most commonly metastases from a cutaneous melanoma. Primary melanoma of the stomach is rare and carries a poor prognosis. Reported here is the case of a 75-year-old man with a primary gastric melanoma who presented with a melena, abdominal pain, and weight loss. Most cases of melanoma are treated by excision of the primary tumor. Patients with melanoma have been treated with adjuvant chemotherapy, radiation therapy, and immunotherapy. None of these modalities has been demonstrated to prolong the survival rate. To improve long-term disease-free survival, early diagnosis and surgical intervention are very important. 흑색종은 피부나 점막에 존재하는 멜라닌 세포에서 기원하는 악성 종양으로 피부에 가장 흔하게 발생한다. 위장관계 점막에서도 흑색종이 발생할 수 있는데 원발성은 매우 드물고 대부분은 피부의 원발성 흑색종으로부터 전이되어 나타난다. 위에 발생한 원발성 흑색종은 매우 드물고 치료 성적이 나쁘고 전이 속도가 빨라서 예후가 매우 나쁘다. 저자들은 혈변, 복통과 체중 감소를 주소로 내원한 75세 남자로 수술 전 진행성 위암으로 진단되어 위전절제술을 시행하였으나 수술 후 위 분문부의 원발성 흑색종으로 식도-위 접합부까지 침범한 증례를 경험하였기에 문헌 고찰과 함께 보고하는 바이다. 흑색종 치료에서 수술은 가장 표준적인 치료법이다. 수술 후 보조 요법으로 항암화학요법, 방사선 치료, 면역 치료 등을 시도해 보았지만 생존율 증가가 입증된 치료 방법은 아직 없는 실정이다. 장기간 생존율을 향상시키기 위해서는 조기 진단과 수술적 치료가 가장 중요하다.

전기자동차용 충전기의 가변출력 및 병렬운전 제어

이상혁(Sang-Hyeok Lee),강성구(Seong-Gu Kang),아와스티 프라카시(Prakash Awasthi),황정구(Jung-Goo Hwang),이승열(Seung-Yul Lee),위한별(Han-Byul Wi),박성준(Sung-Jun Park) 전력전자학회 2013 전력전자학회 논문지 Vol.18 No.2

릴레이를 이용한 차량용 배터리의 가변 충전기

송성근(Sung-Geun Song),정승태(Seung-Tae Chung),강성구(Sung-Gu Kang),이상훈(Sang-Hun Lee) 한국조명·전기설비학회 2012 조명·전기설비학회논문지 Vol.26 No.9

This research is to develop satiable battery charger with a variety of capacity and voltage specifications of battery. For this, voltage or current were controlled through buck converter which is DC voltage that already received three-phase at primary side and passed bridge rectifier diode. And, it was comprised of full-bridge converter and HFTR for insulation and a square wave AC. The transformer primary side was comprised in series to divide certain charging current and the secondly side was comprised of 6 fixed transformers so that they can generate certain amount of power and various output voltage through relay parallel compound 6 DC Link outputs. To confirm such structures verification and validity, simulation with PSIM was conducted, and validity of proposed variable charger system was verified through 3kW stack production.

하지 동맥경화증의 수술 전 진단에서 고식적 혈관조영술과 다중검출 나선식 컴퓨터 혈관조영술의 비교

이강율(Kang Yool Lee),김일명(Il Myung Kim),유병욱(Byung Ook You),윤진(Jin Yoon),박상수(Sang Su Park),신동규(Dong Gue Shin),강성구(Sung Gu Kang),황호경(Ho Kyung Hwang),이성아(Sung A Lee) 대한외과학회 2008 Annals of Surgical Treatment and Research(ASRT) Vol.74 No.4

Purpose: We performed this study to assess the suitability of conventional angiography (CA) vs. multi-detector row helical CT angiogram (MD-CTA) as a method of preoperative diagnostic imaging for low extremity arterial surgery. Methods: From February 2004 to September 2006, 23 patients (4 claudicants, 19 limb-threatening ischemia) were studied with CA and MD-CTA preoperatively. The site and degree of stenotic or occlusive lesions in arterial segments from the renal artery to the dorsalis pedis artery were compared with both methods. We also compared the surgical inflow and outflow site changes in preoperative planning based on CA and MD-CTA and the final outcome. Additional diagnostic value and test-related complications were also analyzed. Results: The median age of patients was 68 years old (range: 43∼89 years), with a male to female ratio of 1.3:1. Twenty-three patients had CA after an MD-CTA scan. One hundred fifty lesions were detected in these patients. The total ratio of consistency for occlusion in CA vs. MD-CTA was 69.6%. Three patients received amputation treatment and eleven patients received a bypass operation. The agree ment between the preoperative plan based on MD-CTA and the final operation was 100%, even in critical limb ischemia. There were no serious complications related to the tests. Conclusion: These findings suggest that MD-CTA is an adequate preoperative imaging study of infrainguinal arterial surgery and may be substituted for conventional angiography without any serious complications.