규칙파를 이용한 방향 스펙트럼 추정방법

김가현,이승휘,민일규,이정환 慶南專門大學 1999 論文集 Vol.27 No.1

관상피판술 : 해부학, 수술시 고려사항, 병적인 상태

김영균,이기혁,여환호,김수관,박노승 大韓顎顔面成形再建外科學會 1996 Maxillofacial Plastic Reconstructive Surgery Vol.18 No.4

The coronal approach is a versatile surgical technique. This methos becomes particulary useful for exposure and internal fixation of midfacial fractures and the harvest of calvarial bone graft to manage the complex facial bone fractures. The rectrospective clinical study on the use of this technique in 10 patients was performes. The result shows that this technique provides the excellent exposure of fractures site, the ability to reduce the fragment accurately and good cosmetic results in incision area. We discussed with literatures review that anatomy, technique, indications, and potential complications of the coronal approach.

Nd:YAG Contact Laser를 이용한 새로운 미세혈관문합술의 실험적 연구

김우경,정전은,박승하,임재호,조진환 大韓成形外科學會 1993 Archives of Plastic Surgery Vol.20 No.3

A comparative study was undertaken to evaluate the contact Neodymium : yttrium aluminum garnet(Nd : YAG) laser system for vascular anastomosis of small caliber blood vessels(diameter 0.5-1.2mm) in the animal model. In this study 40 femoral arteries and 40 femoral veins of Sprague-Dawley rats were anastomosed by contact laser assisted microvascular anastomosis(LAMA) utilizing 3 stay sutures which were placed 120 degrees apart and the intervals welded with contact Nd : YAG laser unit, conventionally sutured anastomosis(CSA) served as controls. The time needed for vascular anastomosis, patency rate (immediate postoperative, postoperative 2nd day, postoperative 1 week, postoperative 4 week), gross and microscopic evaluations were compared to conventional microsurgical suture technique. The results are as follows : (1)Post-operative patency rate was 82.5% for femoral artery and 75% for femoral vein by contact LAMA technique compared to 90% and 75% by CSA technique at post operative 4 weeks. (2)Less time-consumed for arterial anastomosis by 6 minutes 23 seconds and venous anastomosis by 8 minutes 55 seconds with contact LAMA technique compared to CSA technique. (3)Grossly almost complete healing had taken place by post-operative 1 week by contact LAMA technique. (4)Aneurysm formation was 5% for femoral artery and 15% for femoral vein by contact LAMA technique compared to 5% and 10% respectively by CSA technique. (5)Microscopically, re-endothelization was complete by post-operative 7th day by contact LAMA technique. There was less medial hypertrophy and hyperplasia and also less inflammatory response compared to CSA.

원적외선 광조사에 의한 도핑되지 않은 반절연성 GaAs의 광전류 전이와 열자극 전류

김화민,박승환,김종재,고석중,최병두 대구효성가톨릭대학교 자연과학연구소 1994 基礎科學硏究論集 Vol.1994 No.1

도핑되지 않은 반절연성 GaAs의 광전류 급냉과 열적 회복효과를 조사하기 위하여, 성장 방법이 다른 두개의 반절연성 GaAs시료에 대해 원적외선 영역(hv≤1.12eV)의 광조사에 의한 열자극 전류(TSC)스펙트럼들이 측정되었다. LEC방법에 의하여 성장된 As가 풍부한 반절연성 GaAs시료에 대한 50K에서의 광전류의 급냉 과정은 두 단계로 대별된다. 광전류 값이 최소가 되는 시간으로 전이시간 t_T를 정의할 때, (1) IR 광조사 시간 t<t_T이면, EL2(기저상태)→EL2^*(준안정상태) 전이에 의하여 광전류가 감소하고, (2)t>t_T이면, persistent photocurrent (PPC)효과에 의하여 광전류는 다시 증가하였다. 이러한 차이는 성장 방법과 조성비에 따른 잔류불순물의 농도가 광전류 변화에 영향을 준 때문으로 판단된다. 한편, 광조사 시간에 따른 TSC 피크들의 급냉과 급냉된 피크들의 열적 회복에 대한 온도 의존성은 EL2의 기저상태와 준안정 상태 간의 전이 또는 열적 회복과정과 거의 일치하였다. 따라서, 광전류의 급냉 전과 후에 각각 다른 형태로 관측되는 TSC스펙트럼 구조는 EL2 또는 EL2^*와 직접적인 관련을 갖는 트랩들의 분포에 의해 결정되고, 이 트랩들은 EL2-점결함 또는 EL2-잔류불순물로 형성된 complex에 의한 것으로 추론되었다. To study the photoquenching and thermal recovery effects in undoped semi- insulating (Sl) GaAs,the thermally stimulated current (TSCI) spectra, by illuminating infrared light (hv≤ 1.12 eV), are measured with two different Sl-GaAs samples, grown by the liquid-encapsulated Czochraski (LEC) and the horizontal bridgeman (HB) methods. In the As-riched Sl-GaAs sample by LEC method, the photo-current (I_ph) quenching process at 50 K consists of the following two stages: (1) quenching of I_ph due to the transition EL2→EL2^* before a transition time t_T and (2) enhancement of I_ph due to persistent photocurrent (PPC) after t_T, where t_T is defined as the time in which I_ph becomes minimum. However, neither re-enhancement of I_ph nor PPC are observed in the Sl-GaAs sample by HB method. This distinction results from the difference on the concentration of residual impurities, dependent on the growing method and composition rate, in the above two samples. The illumination time dependence of the quenching of TSC peaks and the temperature dependence of their thermal recovery are nearly fitted into those of the ground-to-metastable-state transition or thermal recovery process of EL2. Asa result, it is inferred that the TSC spectral structure, showing different feature before and after IR-quenching, is determined by the distribution of traps associated directly with EL2 or EL2^* and the traps are originated from a complex of EL2-point defect or EL2-residual impurities.

嶺南地方 全業養豚場의 돼지 繁殖實態 調査

河成珍,金鳳煥 COLLEGE OF AGRICULTURE KYUNGPOOK NATIONAL UNIVERSI 1984 慶北大農學誌 Vol.2 No.-

A partial and preliminary report of the reproductive performance of swine in the south eastern part of Korea (Youngnam province) during 1983 was given. For the 871 farrowings recorded, the mean litter size at birth was 8.9 and 0.61 piglet per litter was stillborn. Of the total number of piglets born alived, some 15.4 percent never reached the age of weaning, the vast majority succumbing within 3 days of birth. The major factor of piglet death from birth to weaning were diarrhoea (34.6%), crushing(17.4), weak pigs (15.8%), starvation(11.8%) and pneumonia (6.7%).

적응-강인 제어기법을 이용한 유압 굴삭기의 궤적 제어

최종환,김용석,김승수,양순용 한국공작기계학회 2003 한국공작기계학회 추계학술대회논문집 Vol.2003 No.-

This paper proposes a combined controller frame of the adaptive robust control(ARC) and the sliding mode control(SMC) for the trajectory tracking control of the excavator to preserve the advantages of the both methods while overcoming their drawbacks, namely, asymptotic stability of adaptive system for parametric uncertainties and guaranteed transient performance of sliding mode control for both parametric uncertainties and external disturbance. The suggested control technique is applied for the tracking of a straight-line motion of end-effector of manipulators, and through computer simulations, its trajectory tracking performances and the robustness to payload variation and uncertainties are illustrated.

화학과 생물 교과서에서 삼투 개념에 관한 설명 유형 분석

고영환,강대훈,박동조,김동욱,백성혜 한국과학교육학회 2002 한국과학교육학회지 Vol.22 No.4

이 연구에서는 고등학교와 대학교 화학과 생물 교과서에 제시된 삼투 개념에 대한 설명 유형 및 그림표현 유형을 분석하였다. 그리고 고등학교 화학Ⅱ 교과서와 생물Ⅱ교과서의 단원을 분석하였다. 분석 결과, 삼투현상에 대해서는 용매의 확산으로 설명하는 유형, 충돌로 설명하는 유형, 수화로 설명하는 유형, 농도의 평형으로 설명하는 유형 그리고 구멍을 막는 것으로 설명하는 유형 등 다섯 가지 유형으로 설명하고 있었다. 그리고 삼투 개념에 대한 설명 유형과 교과서에 제시된 그림 표현 유형 사이에 일치하지 않는 경우도 분석되었다. In this study, we analyzed types of explanation on osmosis concept that were represented in chemistry and biology textbooks of high school and college. There were 5 types of explanation on osmosis concept. The types of explanation were diffusion of solvent, collision, hydration, equilibrium of concentration and screen of holes. Last two types of explanation were classified into misconceptions. The various types of explanation on osmosis concept might cause to have be a reason that students had many misconceptions and to feel difficult to learn about osmosis concept. Many of textbooks is accord to types of concept explanation and figure explanation on osmosis but some is not

인공와우이식에서 전기자극 등골근반사의 임상적의의

김리석,안영민,이승환,김동환 대한이비인후과학회 2000 대한이비인후과학회지 두경부외과학 Vol.43 No.10

TPN 처방시스템을 이용한 약국업무 개선

조영환,김정태,김승란,백지은,김미경 한국병원약사회 2000 병원약사회지 Vol.17 No.1

As a part of a plan to improve the multifunctional hospital information system, Asan Medical Center has invented the COES (Clinician's Order Entry System) for the physicians which involves computerized TPN prescription. As an initial step, an outline of the system has been formulated after collection relevant materials from various sources including foreign materials. This project simplifies and standardizes COES between physicians and pharmacists. By introducing this system, we could minimize the possible errors during inputing the inscription and converting the requirements to the volumes to prepare the required medicine. Units of prescribed volume were automatically changed through the computerization of TPN order. This procedure can save time and man-power for preparing the medicine by using Automatic TPN Prescripter. All of these has encouraged us to seek more active TPN consultation for the systemical examination and monitor TPN inscription, and to provide patients with TPN of a good quality.

흰쥐에서 할로페리돌에 의해서 유발된 강경증에 미치는 후구 적출의 영향

전승호,김선장,배기환,이순철 충남대학교 약학대학 의약품개발연구소 1992 藥學論文集 Vol.8 No.-

We attempted to clarify the effect of bilateral olfactory bulbectomy on catalepsy induced by haloperidol in rats. The incidence of catalepsy induced by haloperidol remarkably increased after lesion of olfactory bulb, which was significantly inhibited by L-5-hydroxytryptophan, L-DOPA, and ginseng's total saponin but reserpine and α-methyl-p-tyrosine were ineffective. The dopamine content of brain was significantly decreased by olfactory bulbectomy, but this result was reversed by ginseng's total saponin.