전자기형 충격파 발생기의 전자기력 특성 해석

최민주,이승환,이종혁,이헌주 제주대학교 공과대학 첨단기술연구소 2001 尖端技術硏究所論文集 Vol.12 No.2

임상용 체외 충격파 쇄석술에서 최근 우수한 성능이 입증되고 있는 솔레노이드를 이용한 전자기학적 충격파 발생기의 전자기학 및 역학적인 특성을 분석하였다. 10kV로 충전된 콘덴서(1㎌)가 솔레노이드 (직경 40mm, 길이 110mm, 구리선의 직경 1mm)를 통하여 순간적으로 방전되면, 솔레노이드 주변을 감싸고 있는 금속판이 진동하여 원통형으로 방사하는 충격파가 발생한다. 소프트웨어 Flux2D를 사용하여 전류의 파형, 금속판 주변의 자속의 세기 및 금속판에 떨림을 야기시키는 전자기력을 계산하였다. 금속판의 두께, 코일의 저항 및 권선수가 금속판에 가하는 전자기력의 효과에 대해 분석하였다.

자율주행 차량의 經路推從에 關한 硏究

이종성,최군호,조용석,박기헌 成均館大學校 科學技術硏究所 1996 論文集 Vol.47 No.1

This paper treats the guide path tracking problem of an experimental automated guided vehicle. An experimental guide path is made of aluminium foil which has width of 2[cm]. When a aluminium foil is used as the guide path, this may be less stable than a conservative rail guide path. In this case, it is necessary to control the steering system which influences the system stability. A digital PD(Proportional and Derivative)controller is used to manipulate the steering system and it is verified by laboratory experiments that the designed AGV tracks the guide path within the range of 3.2[cm] deviation. In order to increase accuracy of the guide path tracking, it would be necessary to introduce the constant speed mode and slow-down speed mode according to the state of guide path.

수면확성기의 음향특성에 관한 연구

이창헌,문종욱,박용석,최찬문,서두옥 제주대학교 해양연구소 1998 해양자원연구소연구보고 Vol.22 No.-

To obtain the fundamental data on a surface speaker made to lure fish school by pure sound, three surface speakers were made of moving coil driver units of 75W and 50W respectively. Their frequency characteristic was measured in the range of 200 - 4mHz that could be used in luring fish school. The results of the measurements in air and sea are follows. 1. The input and output wave forms of a surface speaker were similar to each other in measurement frequencies in air. Then sound pressure of a surface speaker made of 75W driver units among them was over 130dB(0dB re 20μ Pa) in the range of 300 - 400Hz maximally. 2. When the surface speaker with 75W driver units emitted the measurement frequencies at sea. Sound pressure classified by the depth of water were over 140dB at 1m and 120dB at 20m(0dB re 1μ Pa) respectively.

지연유합과 불유합에서 저신호 강도 초음파의 유용성

윤여헌,김종오,고영도,유재두,정준모,오종건,방한천,최창호,신명철 대한골절학회 2003 대한골절학회지 Vol.16 No.1

목 적 : 저 신호 강도 초음파를 이용한 지연유합과 불유합의 치료에 대한 유용성을 알아보고자 하였다. 대상 및 방법 : 2001년 7월부터 2002년 5월까지 본원에 내원한 지연유합 7례와 불유합 8례를 대상으로 5개월간 저 신호 강도 초음파로 치료하여 5개월후 골유합 여부를 알아 보았다. 결 과 : 총 15례 중 대퇴골 간부 2례, 경골 간부 1례, 상완골 간부 1례, 요골 1례의 지연유합에서 골유합을 얻었고 대퇴골 간부 불유합 3례에서 유합을 얻었다. 지연주합은 71%의 유합율을, 불유합은 37.5%의 유합율을 보였다. 결 론 : 저 신호 강도 초음파는 골유합을 촉진 시킬 수 있으며 지연유합에서 시도해 볼 만 하나 불유합 치료를 위해서는 보다 많은 연구가 필요 하다. Purpose : To evaluation of usefulness of low-intensity ultrasound for nonunion and delayed union. Materials and Methods : For 5 months, we treated 7 delayed union and 8 nonunion using low-intensity ultrasound. After 5 months, in checked X-ray AP and Lateral view, when cortical bridge formation was done, we through union. Results : In 7 delayed union, 5 cases-2 femur, tibia, humerus, radius were healed. In 8 nonunion, 3 femur nonunion were healed. Union rate was 71% in delayed union 37.5% in nonunion. Conclusion : we thought that the low-intensity ultrasound has capacity of induction of union and was considered as the method of treatment for delayed union.

분산 TTP를 이용한 공정한 부인봉쇄 프로토콜의 성능평가

이헌길,최종권 강원대학교 정보통신연구소 2001 정보통신논문지 Vol.5 No.-

Non-repudiation service is to generate, collect, maintain, make available, and validate evidence concerning a claimed event or action in order to resolve disputes about the occurrence or non occurrence of the event or action. Non-repudiation mechanisms require fairness. To provide fairness in the non-repudiation service, most proposed methods make use of a centralized TTP(Trusted Third Praty) that located in the center. But, the centralized TTP's overhead is rapidly increased if the originator transactions are increased. In this paper, we try to solve this problem using distributed TTPs that are located in each local domain.

임신중 우측난소의 자궁내막장종의 성장과 파열의 1례

이종학,홍순도,남상욱,최종호,허광현,박일영 啓明大學校 醫科大學 1993 계명의대학술지 Vol.12 No.2

계명의대 산부인과에서 35세된 경산부에서 임신과 동반된 우측 난소의 자궁내막낭종의 성장과 파열을 경험하였기에 이에 문헌고찰과 함께 보고하는 바이다 Pregnancy had long been considered to have beneficial effect on endometriosis. During the pregnancy, extrauterine endomertrial tissues did not growth or enlarged because of physiologic amenorrhea and producing hormonal effect. However, we experienced a patient who underwent emergency exploratory laparotmy at gestation week 34/4 for rupture of an ovarian endometriotic cyst. The patient had a Cesarean section delivery of a 1,960gm female baby, who died at 1st day of life.

Staphylococcus aureus와 Coagulase-Negative Staphylococcus Species에 대한 Arbekacin의 시험관내 항균력

위성헌,강진한,허동호,이동건,김상일,김양리,최정현,김종현,유진흥,허재균,신완식,강문원 대한감염학회 2001 감염 Vol.33 No.4

Background : Most strains of methicillin-resistant Staphylococcus aureus (MRSA) now exhibit high-level resistance to various antibiotics, such as β -lactam antibiotics, aminoglycosides, macrolides, tetracyclines and quinolones. Recent reports describing the therapeutic failure of vancomycin for MRSA infections have arisen considerable concerns regarding the emergence of MRSA strains, which will require new therapeutic agents. Arbekacin, an aminoglycoside antibiotic, has antibacterial activity against both gram-positive and gram-negative bacteria and is stable in the presence of aminoglycoside inactivating enzymes produced by S. aureus. In this study, we compared the antibacterial activity of arbekacin with those of vancomycin, gentamicin, and amikacin against Staphylococcus aureus (S. aureus) and coagulase-negative staphylococci (CNS). Methods : For a collection of 549 S. aureus and 251 CNS isolates from three Catholic University Hospitals in Korea, minimum inhibitory concentrations (MICs) of arbekacin, vancomycin, amikacin and gentamicin were determined by agar dilution method using Mueller-Hinton agar according to NCCLS (National Committee for Clinical Laboratory Standards, USA)criteria. Results : Among 549 S. aureus isolates, 278 isolates were MRSA and 271 isolates were methicil sensitive S. aureus (MSSA). MIC50 & MIC90 of arbekacin against 549 S. aureus were 0.5 & 1 ㎍/mL, and MIC50 & MIC90 of vancomycin were 1 & 1 ㎍/mL. MIC of arbekacin against 549 S. aureus isolates ranges from 0.03 to 4 ㎍/mL, and MIC of vancomycin against 549 S. aureus ranges from 0.25 to 2 ㎍/mL. MIC90 of amikacin against 549 S. aureus was 32㎍/mL, and that of gentamicin was 128 ㎍/mL. MICs of amikacin and gentamicin were variable, ranging from 0.125 to 256, and otherwise arbekacin and vancomycin revealed relatively narrow range of MICs. MIC90 of arbekacin against 278 MRSA isolates & 271 MSSA were 1 & 0.5 ㎍/mL, and those of vancomycin against MRSA & MSSA were 1 & 1 ㎍/mL. MIC90 of amikacin against 278 MRSA & 271 MSSA isolates were 32 & 4 ㎍/mL, and that of gentamicin against MRSA & MSSA isolates were 128 & 32 ㎍/mL respectively. Among 251 CNS isolates, 122 isolates were MRCNS and 129 were MSCNS. MICSO & MIC90 of arbekacin against 251 CNS isolates were 0.25 & 2 ㎍/mL, and those of vancomycin were 1 & 2 ㎍/mL. MIC of arbekacin against 251 CNS isolates ranges from 0.015 to 32 ㎍/mL, and that of vancomycin isolates ranges from 0.25 to 2 ㎍/mL, MIC90 of arbekacin against 122 MRCNS & 129 MSCNS isolates were 2&0.3 ㎍/ML, and those of vancomycin were 2&s ㎍/ML. MIC90 of amikacin against 251 CNS isolates was 32 ㎍/ML, and that of gentamicin was 128 ㎍/ML for CNS. MIC90 of amikacin against 122 MRCNS & 129 MSCNS isolates were 128 & 8㎍/mL, and those of gentamicin ere 256 & 32 ㎍/mL. Conclusion : Considering above results, arbekacin can be useful agent against most strains of MRSA and MRCMS, which exhibit high-level resistance to amikacin and gentamicin. (Korea J Infect Dis 33:254~260, 2001)

Novolak resine의 合成과 熱特性에 關한 硏究

박종헌,최승재 三陟大學校 1998 論文集 Vol.31 No.2

Novolak resin was Synthesized and acid catalyzed condensation of phenol with 37% from aldehyde and treated with the mixture of methanol and water as Solvents in order to get improved thermal properties of novolak. The initial decomposition temperature(??) of novolaks was observed in the range of 100.39℃. The glass transition temperature(??)of novolaks was varied on the change of mixing ratio of H₂O/MeOH.

수중 가청음에 대한 멸치 어군의 행동 반응

이창헌,문종욱,박용석,최찬문,서두옥 제주대학교 해양연구소 1998 해양자원연구소연구보고 Vol.22 No.-

A field experiment was carried out to confirm the effect of underwater sound on the luring of fish school using a surface speaker at the coast of Cheju Island. Underwater sounds that were emitted for the luring of fish school were the pure sound of which frequencies were 200Hz and 300Hz. 1. The sound pressure level of 100Hz. 200Hz. 300Hz. 500Hz and 1000Hz classified by the depth of water at sea were 95dB. 100dB. l00dB 80dB and 60dB at 1m. 90dB. 95dB. 88dB. 70dB and 45dB at 10m. 87dB, 90dB. 82dB. 65dB and 42dB at 20m respectively. 2. The effect of the emitted pure sound of 200Hz and 300Hz was remarkable for luring of fish school in about 30 minutes after sound emission. Then Sound pressure was 120 - 130dB. The lured fish school was the shoal of anchovy 3. The fact that anchovy school geathered at 200Hz and 300Hz suggested that this fish school did not show sensitive response to the change of frequencies.

10주간의 체계적 운동이 노인들의 골밀도에 미치는 영향

이규문,최종환,김창범,김태헌 忠北大學校 平生體育硏究所 1997 平生體育硏究所 論文集 Vol.9 No.-

An experimental study was designed to investigate the effects of 10-weeks exercise on the bone mineral density (BMD) in women (ages 55 to 74). The subjects were placed into two age groups; middle aged group(n=19, 62.2±2.5 yrs) old group(n=16, 69±2.3 yrs). All subjects completed the bone mineral density test ( Radius and Ulna) by computed tomography both prior to and immediately following 12-weeks program. Both experimental groups participated in an 12-week exercise program consisting of three 80-min supervised exercise bouts a week. A pairs T-test was used to examine differences between pre-and post-test scores in the bone mineral density, depending on each age group. First the significant improvement (1.7%) appeared on BMD in all subjects together after 10-weeks exercise. Specifically, the middle aged group showed statistically significant increase(1.2%) between pre-and post-test scores in he bone mineral density after 10-weeks program. However, even though the improvement (2.2%) of BMD in the older group was not significant in statistics, the improvement(2.2%) of BMD in the older group is bigger than the improvement (1.2%) of BMD in the middle aged group. Therefore, the results suggest that improvements in BMD may be affected by acute exercise and may support the affective beneficence of exercise for older populations.