미니플레이트의 골내 고정원 적용 시 초기 안정성에 영향을 주는 요인에 대한 3차원 유한요소법적 연구

이남기,최동순,장인산,차봉근 대한치과교정학회 2008 대한치과교정학회지 Vol.38 No.5

본 연구는 골내 고정원으로 사용하는 미니플레이트 시스템의 초기 안정성에 영향을 주는 요인에 대해 알아보기 위해 시행하였다. 미니플레이트의 고정에 사용되는 미니스크류의 길이, 수 및 적용되는 교정력의 방향에 따른 골내응력 분포 양상과 미니스크류의 변위 정도를 분석하기 위하여 3차원 유한요소분석을 시행하였다. 단순화한 골 모델에 6 hole의 곡선형 미니플레이트를 위치하고 직경 2 mm의 미니스크류로 고정하되 각각 6 mm와 4 mm 길이의 두 가지 종류로 세 개 또는 두 개로 고정한 총 네 개의 유한요소모델을 제작한 후 각각의 모델에서 4 N의 교정력을 미니플레이트의 고정되지 않은(unfixed) 가장 원심측 두 개의 hole을 연결한 가상의 축에 대해 0˚, 30˚, 60˚, 90˚ 방향으로 각각 적용하였다. 미니플레이트를 고정하는 미니스크류가 동일 길이일 경우 개수가 작을수록, 동일 개수일 경우 길이가 짧을수록 골에 나타나는 최대 응력과 미니스크류의 최대 변위가 증가되었다. 골에 나타나는 최대 응력은 해면골에 비해 피질골에 집중되어 응력의 대부분은 피질골에서 흡수되었다. 미니플레이트의 가상의 축에 대해 교정력의 견인방향이 증가할수록 골내의 최대 응력과 미니스크류의 최대 변위가 증가되었다. 골내의 최대 응력과 미니스크류의 최대 변위는 적용된 견인력 지점에서 가장 가까운 미니스크류 고정 부위였다. 이상의 결과로 미니플레이트 시스템의 초기 안정성을 위해 2 mm 직경의 미니스크류를 사용 시 4 mm보다는 6 mm 길이의 미니스크류를, 2개보다는 3개식립하는 것이 더 유리하며, 미니플레이트의 가상의 축에 대해 적용하는 교정력의 견인방향이 가급적 일치되도록 미니플레이트를 위치시키는 것이 좋을 것으로 생각된다. Objective: The purpose of this study was to evaluate the stress distribution in bone and displacement distribution of the miniscrew according to the length and number of the miniscrews used for the fixation of miniplate, and the direction of orthodontic force. Methods: Four types of finite element models were designed to show various lengths (6 mm, 4 mm) and number (3, 2) of 2 mm diameter miniscrew used for the fixation of six holes for a curvilinear miniplate. A traction force of 4 N was applied at 0˚, 30˚, 60˚, and 90˚ to an imaginary axis connecting the two most distal unfixed holes of the miniplate. Results: The smaller the number of the miniscrew and the shorter the length of the miniscrew, the more the maximum von Mises stress in the bone and maximum displacement of the miniscrew increased. Most von Mises stress in the bone was absorbed in the cortical portion rather than in the cancellous portion. The more the angle of the applied force to the imaginary axis increased, the more the maximum von Mises stress in the bone and maximum displacement of the miniscrew increased. The maximum von Mises stress in the bone and maximum displacement of the miniscrew were measured around the most distal screw-fixed area. Conclusions: The results suggest that the miniplate system should be positioned in the rigid cortical bone with 3 miniscrews of 2 mm diameter and 6 mm length, and its imaginary axis placed as parallel as possible to the direction of orthodontic force to obtain good primary stability.

일측 하퇴 의족 착용자의 절단단 길이에 따른 보행특성

조병모,변주남,김기순,김석산,박종 조선대학교 부설 의학연구소 1999 The Medical Journal of Chosun University Vol.24 No.1

This report studied 31 male patients who were in one hospital in Kwangju or came to a prosthesis clinic and are 15 normal control group to analyze the gait characteristics according to the stump length in the prosthesis users with the unilateral below-knee amputations. The patient group was divided into a short stump subgroup of 13 patients and a long stump subgroup of 18 patients according to the stump length, the control group was randomly sampled from 15 males who have similar age, height and weight to the experimental group. The results of analysis are summarized as follows. 1. There were no significant statistical differences of the general characteristics between patient and control groups and there was no difference of characteristics by patient groups except the mean gait distance a day. 2. Of 33 patients with amputation, 18 patients (57.8%) had phantom pain and 25 cases (80.6%) had neuroma. 3. Gait velocity, stride length of the affected side, step length of the sound side and base support among gait characteristics show a significant difference according to the stump length in the state excluding the effects of other factors (p<05) and the group with long stump showed closer gait characteristics to normal persons than those with short stumps. In conclusion, among the patients of unilateral below-knee amputations, the stump length affects the gait characteristics such as gait velocity, stride length, step and base of support and it is found that as the stump length gets longer, it shows the similar characteristics to gait characteristics of normal persons and long unilateral below-knee amputation can secure better gait characteristics.

一部 美容業 從事者들의 織責別 腰痛 有病率과 關聯要因

김춘일,박종,류소연,김석산,김기순,하상호,변주남 조선대학교 부설 의학연구소 1999 The Medical Journal of Chosun University Vol.24 No.1

To find the prevalence and related factors of low back pain experienced by some beauticians. a survey was made toward 252 beauticians in Kwangju City from March 1st to April 1st, 1998. The results were as follows; 1. The prevalence rate of low back pain among the respondents for the last week was 59.5%. 2. The aid group and staff group with low back Pain had significantly longer duration of work than those without low back pain. Managers who had bad posture with twisted or too much extended back showed a significantly higher prevalence of low back pain than those with good posture during work(P<05). 3. Aid group with low back pain showed significantly higher points at total stress score, depression score, general health score and vitality score than those without low back Pain. The staff group with low back pain showed significantly higher points for total stress score, sleep disorder and anxiety score, depression score, general well-being and vitality score than those without low back pain. Managers with low back Pain showed significantly higher points of stress at social performance and self confidence (P<05) than those without low back pain. The above results suggest that low back pain is related to different jobs and work environments for beauticians. So effective measures and further studies against risk factors must be made considering their jobs. To prevent or reduce low back pain, appropriate management of stress for beauticians is necessary.

Effects of e2f3 gene deletion in mice

Ki-Hoan Nam,Hae-Rim Kim,Eun-Kyeung Kim,San-Mi Cho,Ki-Hoon Lee,Young-Won Seo,Young-Suk Won,Hoyoung Kang,won-Kee Yoon,Hyoung-Chin Kim 한국실험동물학회 2020 한국실험동물학회 학술발표대회 논문집 Vol.2020 No.2

횡방향 철근을 합성섬유로프로 대체한 RC기둥의 압축거동

홍기남 ( Ki Nam Hong ),문상렬 ( Sang Yeol Moon ),박재규 ( Jae Kyu Park ),한상훈 ( San Hoon Han ),정규산 ( Gyu San Jung ) 충북대학교 산업과학기술연구소 2012 산업과학기술연구 논문집 Vol.26 No.2

The purpose of this paper is to evaluate strength and ductility capacity of strengthening using synthetic fiber rope as lateral reinforcement member of the concrete column and confirm possibility using it as alternative material of rebar. To analyze the reinforcement effect of the specimen, concrete strength, lateral reinforcement interval, lateral and reinforcement member type are set as variables to produce 14 full-size columns. This study uses the flexibility of synthetic fiber rope for lateral reinforcement of column in spiral format. To evaluate lateral reinforcement performance of synthetic fiber rope, it was compared to generally used steel tie reinforcement method and load and displacement, change rate of reinforcement member, and fracture mode were analyzed. According to such results, rebar reinforcement specimen showed load increasement ratio of 16?34%. And SM rope reinforcement specimen showed load increasement ratio of 1 - 8% while PP rope reinforcement specimen showed -6 ~ 3%. Also steel tie reinforcement specimen showed ductility fracture depending on reinforcement intervals but synthetic fiber rope reinforcement specimen mostly showed brittle fracture. As a result, lateral binding effect of concrete column through synthetic fiber rope was shown to be insufficient.

비파괴 실험을 통한 콘크리트 압축강도 추정

홍기남, 이한솔, 김준일, 한상훈, 정규산 충북대학교 건설기술연구소 2012 建設技術論文集 Vol.31 No.2

본문참고.

Pb(Mg<SUB>1/3</SUB>Nb<SUB>2/3</SUB>)O₃-PbTiO₃-Pb(Ni<SUB>1/2</SUB>W<SUB>1/2</SUB>)O₃ 세라믹의 유전특성에 관한 연구

柳南山(Nam-San Yoo),柳基元(Ki-Won Ryu),李成甲(Sung-Gap Lee),李永熙(Young-Hie Lee) 대한전기학회 1991 전기학회논문지 Vol.40 No.9

케미컬 앵커 기초시스템의 인발성능

홍기남, 한상훈, 박재규, 정규산, 김성보 충북대학교 건설기술연구소 2014 建設技術論文集 Vol.33 No.1

본문참조

기후변화 시나리오에 따른 미래 참다래 궤양병 피해 예측

도기석 ( Ki Seok Do ),정봉남 ( Bong Nam Chung ),최경산 ( Kyung San Choi ),안정준 ( Jeong Joon Ahn ),좌재호 ( Jae Ho Joa ) 한국농림기상학회 2016 한국농림기상학회지 Vol.18 No.2

RCP4.5와 RCP8.5 미래 기후 변화 시나리오자료와 참다래 궤양병 피해 예측 모형인 D-PSA-K, 미래 참다래 재배적지 지도를 활용하여 궤양병의 미래 피해를 예측하고 참다래 궤양병의 발생 변화의 경향성을 찾아 보았다. 병원 세균에 의한 감염이 충분히 있다는 가정 아래에서 RCP4.5와 RCP8.5 시나리오의 2020년대와 2050년대에서 궤양병의 최대이병주율은 제주도와 남해안 일부 지역을 제외한 대부분의 지역에서 75% 이상으로 나타날 것으로 예측되었다. 두 시나리오들 모두에서 월동기 저온환경이 없다는 가정 아래에서의 참다래 궤양병에 의한 가지 피해량은 거의 모든 재배가능지에서 증가될 것으로 예측된 반면에 월동기 저온에 의한 가지 피해량 증가율은 거의 모든 재배가능지에서 감소할 것으로 예측되었다. 지역 및 시나리오별로 궤양병 피해의 증가 및 감소의 경향은 다르게 나타날 것으로 예측되었다. RCP4.5 시나리오에서 2050년대에 2020년대에 비하여 10% 이상 최대 이병주율의 증가가 일어날 것으로 예측된 참다래 재배 가능지는 전체 재배 가능지의 3.14%, RCP8.5 시나리오에서는 25.41%였다. We estimated the averaged maximum incidences of bacterial canker at suitable sites for kiwifruit cultivation in 2020s and 2050s using D-PSA-K model with RCP4.5 and RCP8.5 climate change scenarios. Though there was a little difference between the estimation using RCP4.5 and that using RCP8.5, the estimated maximum disease incidences were more than 75% at all the suitable sites in Korea except for some southern coastal areas and Jeju island under the assumption that there are a plenty of infections to cause the symptoms. We also analyzed the intermediate and final outputs of D-PSA-K model to find out the trends on the change in disease incidence affected by climate change. Whereas increase of damage to kiwifruit canes in a non-frozen environment caused by bacterial canker was estimated at almost all the suitable sites in both the climate change scenarios, rate of necrosis increase caused by the bacterial canker pathogen in a frozen environment during the last overwintering season was predicted to be reduced at almost all the suitable sites in both the climate change scenarios. Directions of change in estimated maximum incidence varied with sites and scenarios. Whereas the maximum disease incidence at 3.14% of suitable sites for kiwifruit cultivation in 2020s under RCP4.5 scenario was estimated to increase by 10% or more in 2050s, the maximum disease incidence at 25.41% of the suitable sites under RCP8.5 scenario was estimated so.

수용성 유황 첨가 콘크리트의 역학 특성 및 탄산화 저항성

홍기남 ( Ki Nam Hong ),지세영 ( Se Young Ji ),박재규 ( Jae Kyu Park ),정규산 ( Kyu San Jung ),한상훈 ( Sang Hoon Han ) 한국안전학회(구 한국산업안전학회) 2014 한국안전학회지 Vol.29 No.4

In this study, two types of water-soluble sulfur, LSA and LSB, were developed and the influence of the water-soluble sulfuron the mechanical properties and durability of concrete were experimentally evaluated. In order to evaluate mechanical properties andcarbonation resistance of concrete with water-soluble sulfur, compressive strength test, flexural strength test, bonding strength test, andcarbonation resistance test were performed. Compressive strength of only concrete with 1% LSA was increased while that of concretewith LSB was proportionally increased with the higher LSB dosage. On the other hand, flexural strength of concrete with LSA and LSBwas increased by 12-41% and 36-74%, respectively. Carbonation resistance of concrete with water-soluble sulfur were increased by25-66%. As a result, it should be noted that the water-soluble sulfur can not only solve the demerit of sulfur concrete but also offer thedurability of sulfur concrete.