炭素纖維시트로 補强된 鐵筋콘크리트 보의 휨補强孝果에 關한 實驗硏究

이정희,김연동,이용택,박순란 大田産業大學校 1999 한밭대학교 논문집 Vol.16 No.1

This study is about an experimental investigation was conducted to examine the feasibility of Carbon Fiber sheet(CFS), a kind of high strength fiber, for repair and reinforcement method of concrete structures. The experimental program included tests of beams different in wrapping method and amount of CFS. The beams were subjected to monotonic loading. In order to practically apply the repair and reinforcement method, further research is needed for the distrtbution, amount, and bond of CFS. In this study, an experiment was conducted for R/C beams reinforced with CFS, for various wrapping method and amounts of CFS. Experimental results showed the wrapping method increasing the bond area and amount of CFS layer caused the increase in the strength of the beams.

접합부 해석모델에 따른 철골조 연성모멘트골조의 비선형 응답

이정희,김연동,이용택 大田産業大學校 2000 한밭대학교 논문집 Vol.17 No.1

The purpose of this study is to evaluate the overstrength inherent in ductile moment resisting frames with two different joint models. The overstrength is obtained by nonlinear static pushover analysis using two analytical models. Only one panel element used in this study can reflect the panel zone deformation explicitly. For this purpose, moment resisting frames are designed using two different seismic design provisions. According to the results of this study, the range of overstrength radio is from 2.8 to 5.6. Also this study shows that explicit modeling of panel zone is more important for the buildings designed in compliance to Korean design provision since Korean provision does not have the requirement of strong column-weak beam.

기계적으로 정착된 철근의 이음길이에 관한 실험적 연구

이용택,황홍순 한밭대학교 2004 한밭대학교 논문집 Vol.21 No.-

In this study, the lap length of headed bars are evaluated through the experimental works. Headed bars are lap-spliced perpendicular to the direction of longitudinal bars in beam. Five beam specimens were tested for the performance evaluation on lap splice. Their variable examined was the lap length of headed bars. Two concentrated loads were applied at the end of lapped bars to make the same magnitude of bending moment for the lapped region. Performances of lap splice were evaluated on the basis of strength, stiffness, and drift capacity. Test results show that 14 times the diameter of bar is suitable as lap length.

서울대학교치과병원 소아치과를 내원한 교정환자의 분포양상에 대한 연구

구용한,현홍근,김정욱,장기택,이상훈,한세현,김종철 大韓小兒齒科學會 2009 大韓小兒齒科學會誌 Vol.36 No.4

과거에 비해 소아 및 청소년기에 교정치료를 시작하는 경우가 증가하고 있으며 따라서 소아치과에서 교정치료가 차지하는 비율 역시 증가하는 추세이다. 이러한 변화에 맞추어 소아치과에 내원하는 교정환자의 분포 양상을 파악하기 위하여 본 연구를 시행하였다. 2006년 1월부터 2008년 12월까지 서울대학교 치과병원 소아치과를 내원한 환자 중 교정 진단 받은 792명을 대상으로 조사를 진행하였으며 다음과 같은 결과를 얻었다. 1. 교정 진단을 받은 환자의 연령 분포는 8세가 22%로 가장 많았고 7세(19%), 9세(16%) 순서로 나타났다. 2. 골격 분포는 골격성 1급 부정교합이 52%로 가장 많았고 3급(29%), 2급(19%)순서로 나타났으며 연령이 낮은 경우 3급 부정교합 환자의 비율이 높은 경향을 보였다. 3. 총 792명의 환자 중 28%인 218명에서 전치부 반대교합을 보였으며 연령이 낮은 경우 그 비율이 높은 경향을 보였다. Distribution of orthodontic patients in pediatric dental clinics has increased recently. So it is worth to study about the present status of orthodontic patients in pediatric dental clinics. The purpose of this study was to recognize the characteristics and orthodontic patterns of orthodontic patients in pediatric dental clinics. The material consisted of distribution and orthodontic analysis records of 792 new patients in the department of pediatric dentistry, Seoul National University Dental Hospital, from 2006 to 2008. Results were as follows 1. In age distribution, 8-year-olds group comprised 22%, 7-year-olds 19%, 9-year-olds 16%, 10-year olds 15%, 11-year-olds 11%, and other age groups comprised 18%. 2. In skeletal patterns, skeletal class Ⅰ patients comprised 52%, class Ⅱ 29%, and class Ⅲ 19%. 3. In vertical facial types mesofacial comprised 41%, brachyfacial 35%, and dolichofacial 24%. 4. Out of 792 patients 218 patients(28%) showed anterior cross-bite, and the occurrence ratio of anterior cross-bite increased as the age decreased.

수직적 안모형태와 치아성숙도의 상관관계에 대한 연구

구용한,현홍근,김정욱,장기택,이상훈,한세현,김종철 大韓小兒齒科學會 2010 大韓小兒齒科學會誌 Vol.37 No.1

본 연구는 수직적 안모형태와 치아성숙도의 관계를 평가하고 이러한 연관성에 대한 사춘기 성장의 영향을 평가하기 위한 것이다. 이번 연구를 위해 7세에서 9세, 13세에서 15세 환자 1306명을 Ricketts의 VERT index를 이용하여 수직적 안모 형태를 분류하였고 환자들의 치령을 Demirjian법으로 평가하여 다음과 같은 결과를 얻었다. 1. 모든 군에서 치령이 역령과 비교 시 통계적으로 유의한 수준에서 크게 측정되었다. 2. 사춘기 연령군에서 brachyfacial type의 경우가 dolichofacial type 보다 치아성숙도가 크게 나타나는 경향을 보였다. 여성의 경우는 통계적으로 유의성있게 차이가 나타났으며, 남성의 경우는 통계적 유의성은 보이지 않았다. 3. Brachyfacial type의 경우 사춘기전 군들과 비교 시 사춘기 군들에서 치아성숙도가 유의성있게 높게 나타났으며, dolichofacial type의 경우는 연령층간 치아성숙도의 차이를 보이지 않았다. The purpose of this investigation was to study the relationship between vertical facial pattern and dental maturation in children in pubertal and pre-pubertal periods. The material consisted of lateral head films and panoramic radiographs of 1306 patients. The subjects were selected according to Ricketts's VERT index and other including criteria. These subjects were divided by VERT index to brachyfacial group and dolichofacial group. In each selected subject, dental age was determined according to Demirjian's dental maturity score. All subjects were distributed according to age, vertical facial type and sex, mean and standard deviation of chronological age, dental age and age difference were determined in each group. And the data were analysed to find the difference of tooth maturation by facial pattern. Findings of this study include: 1. In all groups, dental age was determined higher than chronological age in statistically significant level. 2. Compared by vertical facial pattern, in pubertal age groups, it seems that subjects with brachyfacial type presented the tendency to have an advanced dental maturation, only in female group. 3. Compared by pubertal period, brachyfacial groups presented more advanced dental maturation in pubertal groups than pre-pubertal groups.

복사열에 노출된 작업복의 열적특성에 관한 실험적 연구

방창훈,이진호,예용택 한국산업안전학회 2002 한국안전학회지 Vol.17 No.3

The purpose of this study was to present the thermal characteristics of the working uniform exposed to the radiation heat. The effect of exposure time and exposure distance on the changes and the relationship between physical properties were investigated experimentally. Regardless of the kind of working uniform, the surface temperature of the working uniform with exposed time sharply increases as exposed distance is more close and the reaching tie of steady state is shorter. The surface temperature of working uniform exponentially decreases as exposed distance become more distant. For the safety of the working man, it is necessary that he work far away at a fixed standard distance from the radiant heat source.

Hanger로 보강된 스터드 접합부의 인장거동에 관한 실험적 연구

박휘규,김승훈,이리형,이용택,황홍순,이정희 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.1(구조계)

This paper presents the tensile behavior of the stud connection between reinforced concrete(RC) and steel members. Hanger reinforcements are placed around the studs to transfer the tensile loads to the opposite side of the concrete member. Six specimens, of which variables were arrangement details of hanger reinforcements and studs. Tensile test results show that hanger reinforcements are effective to increase tensile strength and ductility. Test tensile strengths of specimens are compared with the nominal strengths by ACI codes(ACI 318-02, ACI 349-99) and PCI 1999.

교통사고로 발생한 대량 환자의 중증도 분류와 이송의 분석

오세현,정용택,김병철,이부수 대한응급의학회 2001 대한응급의학회지 Vol.12 No.4

Background: Triage and transportations are important and life-saving medical task performed at the site of mutiple-casualty incidents(MCIs). We pursued three road traffic accidents victims to find out any problem in triaging and transporting them, and to provide an information for equipping an local disaster planning. Methods: The medical records of 70 consecutive patients who were transported to five emergency facilities in Kangnung, on three MCIs from 1998 to 2000, were analysed, retrospectively. The intervals and types of transport vehicles were analysed. We compared the prehospital time between severity-based groups, which were graded into 3 groups according to the Triage score(0,1~8,9). Results: Among the 70 patients, 33 patients(47.1%), 21 patients(30%), and 16 patients(22.9%) were transported to Level I, Level II, and Level III trauma centers, respectively. The time elapsed from scenes to the Level I trauma center was significantly shorter(p=0.003) than to others, but no differences in the mean Triage score between trauma centers were seen(p>0.05). The 119 rescue services transported 58.6%(41 patients) of victims to emergency facilities, and 58.5%(24 patients) of them was concentrated to Level I. There were no significant differences in the prehospital time between three Triage score groups(p>0.05). Conclusion: There was no medical control such as triage and transportation in the cases of three MCIs. In the construction of emergency medical service system(EMSS) preparing MCIs or disasters, we suggest the integration and unification of 119 rescue services and emergency medical information centers for effective medical control. We propose to making a new and simple triage guideline. The prehospital personnel should be educated and disaster drills should be performed under the guideline.

양극성 기분장애에서 세로토닌 수용체 유전자의 다형성(102T/C)에 관하여

지익성,신석철,왕성근,이선우,신용재,김충수,김상국,최하석,오승용,류택근,이영호 대한생물치료정신의학회 1999 생물치료정신의학 Vol.5 No.2

근위 대퇴정을 이용한 대퇴 전자부 골절의 치료

문영완,서동현,강신택,권덕주,지용남,이기병 대한골절학회 2003 대한골절학회지 Vol.16 No.1

목 적 : 근위 대퇴정을 이용한 고령 환자의 대퇴전자간 골절의 치료결과에 대해 보고하고자 한다. 대상 및 방법 : 2001년 4월부터 2002년 2월까지 대전자부에서 소전자에 이르는 횡선골절 및 소전자 주위 분쇄골절로 압박고 나사 고정이 용이하지 않은 전자간 골절, 일반적인 전자간 골절에 대해 근위 대퇴정을 사용해 치료한 80례 중 추시가 가능했던 71례를 대상으로 하였으며, 추시과정 중 골유합 시기, 대퇴경간각, 지연나사의 활강, 수술시간 및 출혈량, 술중 및 술후 합병증 수술시 주의사항을 조사하였다. 결 과 : 평균연령은 77.5세, 평균추시기간은 9개월이었다. Evans의 분류법으로 골절을 분류하여 안정성, 불안정성 골절은 30례, 41례였다. 평균 골 유합 시비는 13.8주였고, 대퇴경간각은 수술직후 131.9 ± 5.21˚, 129.9 ± 6.04˚ 였으며 평균지연나사의 활강은 4.21±4.13㎜였다. 수술시간은 평균 61분, 출혈량은 평균 0.67pint(134cc)였다. 술중 합병증으로는 정복 실패 1례, 원위고정나사 삽입시 피질골 골절 1례, drill bit 파손 1례가 있었으며, 술후 합병증으로는 대퇴 경간각 소실(5도이상) 12례, 경부골절의 발생이 2례, 지연나사의 관절내 돌출 1례였다. 결 론 : 대퇴골 전자부 골절의 치료로 근위 대퇴정은 정확한 삽입 위치, 삽입시의 조심스러운 확공, 지연나사의 연골하 골에 단단하게 고정시키는 등의 주의를 한다면 수술시간, 출혈량 감소 등의 술중 합병증을 줄이고, 견고한 내고정을 통한 조기 보행을 가능하게 하며, 좋은 골유합 등이 기대되므로, 특히 고령, 분쇄골절, 역행성 골절, 골다공증이 심한 경우에서 바람직한 수술방법으로 사료된다. Purpose : To evaluate the treatment results of geriatric intertochanteric fractures using a proximal femoral nail. Materials and Methods : From April 2001 to February 2002, 71 cases of the intertrochanteric fractures involving lesser trochanter, transverse or reverse oblique intertrochanteric fracture. We evaluated the bone union time, neck-shaft angle, lag screw sliding by follow up radiographs, operation time, blood loss and complications. Results : The average age was 77.5 years old, the mean duration of follow-up was 9 months and the mean duration of bone union was 13.8 weeks. The average neck-shaft angle on immediate postop. x-ray was 131.9 ± 5.21˚ and 129.9 ± 6.04˚ at last follow up and the average lag screw sliding was 4.21 ± 4.13㎜. The average operation time was 61 minutes and blood loss was 0.67 pints(134cc). Intraoperative complications were inadequate reduction in one case, difficulty in distal transfixing in one case and drill bit failure in one case and postoperative complications were loss of neck-shaft angle(more than 5 degree) in 12 cases, femur neck fracture in 2 cases and intraarticular cutting out of femur neck screw in one case. Conclusions : The use of the proximal femoral nail could be appropriate for the fixation of communited or reverse oblique intertrochanteric fracture in elderly, osteroporotic patients for early ambulation, preventing shortening and rotation deformity, and reducing operation time and blood loss.