Ribbon형 Co1-x Crx (x=0.27, 0.29, 0.30, 0.32, 0.35) 합금의 자기특성

장현숙,김미양,이장로,이용호 숙명여자대학교 자연과학연구소 1994 자연과학논문집 Vol.- No.5

급냉법으로 리본형 결정질 Co1-x Crx (x=0.27, 0.29, 0.30, 0.32, 0.35)합금을 제조하여 Cr의 조성에 따른 자기적 특성을 조사하였다. 포화자화값은 벌크값보다 컸지만 박막의 경우보다는 작았다. Cr의 함량이 증가함에 따라 포화자화값은 감소하였다. 27 at.% Cr의 경우를 예외로 하면 Cr 함량 증가에 따라 결정립의 크기는 감소하였고, 항자력은 증가하였다. 리본형 Co1-x Crx 는 포화자화값의 온도 의존성이 비정질 시료인 경우와 유사한 경향을 나타내었으며 Cr의 함량이 증가할수록 Curie온도(Tr)는 감소하였다. Cr 함량의 증가에 따라 exchange interaction의 평균자승거리<r²>와 spin wave stiffness 상수D는 감소하는 경향을 나타내었다. 천이금속(Co)의 원자당평균 자기모멘트는 Cr의 증가에 따라 선형적으로 감소하였다. The magnetic cnaracteristics of crystalline Co1-x Crx (x=0.27, 0.29, 0.30, 0.32, 0.35) ribbons prepared by the rapid solidification were investigated. The saturation magnetization for ribbon was greater than that for bulk alloys containg the same amount of Cr. but smaller for the films. The grain size of ribbon became smaller and coercive force increased with increasing Cr contents except case of 27 at.% Cr. The saturation magnetization decreased with increasing Cr contensts. The temperature dependence of saturation magnetization for Co1-x Crx ribbon showed the similar behavior as the amorphous alloy and the Curie temperatures were decreased with the increase of Cr contents. The spin wave stiffness constant and the mean square range of exchange interaction, also were decreased. The average magnetic moment per transition metal atom was linearly decreased with increasing the contents of Cr.

뇌졸중의 운동신경기능 회복

장성호,권용현 영남대학교 의과대학 2005 Yeungnam University Journal of Medicine Vol.22 No.2

Stroke is a leading cause of chronic physical disability. The recent randomized controlled trials have that motor function of chronic stroke survivors could be improved through physical or pharmacologic intervention in the stroke rehabilitation setting. In addition, several functional neuroimaging techniques have recently developed, it is available to study the functional topography of sensorimotor area of the brain. However, the mechanisms involved in motor recovery after stoke, are still poorly understood. Four motor recovery mechanisms have been suggested, such as reorganization into areas adjacent to the injured primary motor cortex (M1), unmasking of the motor pathway from the unaffected motor cortex to the affected hand, attribution of secondary motor areas, and recovery of the damaged contralateral corticospinal tract. Understanding the motor recovery mechanisms would provide neurorehabilitation specialists with more information to allow for precise prognosis and therapeutic strategies based on the scientific evidence; this may help promote recovery of motor function. This review introduces several methodologies for neuroimaging techniques and recovery after stroke. Perspectives, for future research are presented.

partial pulpotomy를 이용한 미성숙 영구치의 치수 치료: 증례 보고

장기택,노승철,한세현,김정욱,김용수 大韓小兒齒科學會 1999 大韓小兒齒科學會誌 Vol.26 No.4

치수치료의 주요한 목적은 구강조직의 본래의 건강을 유지하는 것이며, 치수치료 시 가장 중요하고 어려운 점은 치수조직의 건강상태 또는 염증의 정도를 결정함으로써 최선의 치료방법을 결정하는 것이다. 미성숙 영구치는 풍부한 혈류 공급으로 다양한 손상에 성공적으로 반응하게끔 치수의 능력을 향상시킴으로써 많은 치수치료 술식을 위한 좋은 조건을 가지고 있다. 기저재(base) 또는 이장재(liner), 간접 치수복조술, 직접 치수복조술, 그리고 치경부 치수절단술을 포함한 여러 종류의 보존적인 치수치료가 미성숙 영구치를 위해 추천되어 왔다. 근래에는 외상으로 인하여 치수노출된 영구절치를 치료하는데 있어 주로 제시된 부분 치수절단술(partial pulpotomy)이 우식으로 인해 치수노출된 영구대구치를 치료하는 또다른 술식으로 제안되고 있다. 부분 치수절단술 후 치아가 다음의 criteria를 만족시킬 때 치유가 되었다고 결론지었다. 1. 임상적 무증상 2. dentin bridge 형성의 방사선학적 증거 3. 방사선상에 치수내 또는 치근단 병소가 없다는 증거 4. 지속적인 치근 발육과 미성숙 치아의 치근첨 형성 5. 성숙된 치아에서 정상적인 상아질의 축적 6. 전기치수검사에서 양성 반응 이에 저자는 미성숙 영구치에서 우식 또는 외상으로 인한 치수노출시 부분 치수절단술을 행하여 양호한 결과를 얻었기에 이를 보고하는 바이다. The primary objective of pulp treatment is to maintain the integrity and health of the oral tissues. The most important and difficult aspect of pulp therapy is determining the health of the pulp, or its stage of inflammation, so that a decision can be made regarding the best form of treatment. Immature permanent teeth are good candidates for many pulp healing procedures, due to their rich blood supply, which is believed to enhance the pulp's ability to react successfully to various insults. Healing was considered to have taken place when the tooth fulfilled the following criteria: 1. Abscence of clinical symtoms 2. Radiographic evidence of dentin bridge formation 3. No intrapulpal or periapical pathosis was evident radiographically 4. Continued root development and closure of the apex in immature teeth 5. Normal dentin apposition in mature teeth 6. Positive response to electrical pulp test This presents a report of cases in which immature permanent teeth, pulp-exposed by caries or trauma, was treated successfully by partial pulpotomy

시간스케일에 따른 해양표면수온과 기온의 변동 및 상관연구

장이현,강용균,서영상 한국환경과학회 2000 한국환경과학회지 Vol.9 No.4

The relationship between air temperature and sea surface temperature are studied using the daily air temperature and sea surface temperature data for 25 years (1970∼1994) at 9 coastal stations in Korea. Seasonal variations of air temperature have larger amplitudes than those of sea surface temperature. The seasonal variations of air temperature leads those of sea surface temperature by 2 to 3 weeks. The anomalies of sea surface temperature and air temperature are positively correlated. The long term anomalies of sea surface temperature and air temperature with time scales more than 1 month are more highly correlated than those of short term, with time scales less than 1 month. Accumulated monthly anomalies of sea surface temperature and air temperature for 6 months showed higher correlation than the anomalies of each month. The magnitudes of sea surface temperature and air temperature anomalies are related with the duration of anomalies. Their magnitudes are large when the durations of anomalies are long.

건물의 에너지 효율을 위한 건축적 계획 방법 연구 : 자연실온과 환경 디자인 요소의 상관도 분석을 중심으로 Focused on Correlation Analysis of NART and Environmental Design Factors

장용성,이현수,서승직,박효순 대한건축학회 2005 대한건축학회논문집 Vol.21 No.2

This study intends to deriving the equation of non-airconditioned room temperature(hereafter referred to as NART) prediction from the correlation analysis of the influence of environmental design factors on the building. The relation between the NART and environmental design factors was analysed by using correlation coefficients. The equation of NART prediction was derived from the regression analysis by experimentation and simulation. In this study, the main results are summarized as follows: The average NART of experiment and simulation were evaluated to 22.0℃ and 22.6℃, respectively. An error of simulation was the 2.7%. The results from correlation analysis was con-elated with the daily average outdoor temperature, soil temperature, solar intensity, relative humidity, and air velocity in order. Con-elation coefficients of the daily average outdoor temperature, NART, and peak air conditioning load were over the 0.75. According to the sensitivity analysis of environmental design factors and air conditioning load in reference model, the influence of air infiltration and window surface ratio were more than outside insultion.

벡터드라이버를 이용한 편측형 선형유도전동기 구동특성에 관한 연구

장용해,임홍우,신사현,조금배,백형래 조선대학교 에너지.자원신기술연구소 2001 에너지·자원신기술연구소 논문지 Vol.23 No.2

The input voltage of Single-sided linear induction motors (SLIMs) is involved with the time harmonics because most LIM is driven by inverter. Therefore the equivalent circuit for an inverter-fed SLIM has t o be modifided to represent every harmonic present in supply voltage. This paper describes that the dynamic characteristic can be used effectively for analyzing the characteristics of a single-sided linear induction motor using vector driver for PI controller.

경구 진정요법하에 시행한 설소대 절제술

장용걸,박호원,이주현,서현우 大韓小兒齒科學會 2009 大韓小兒齒科學會誌 Vol.36 No.4

Tongue-tie is a congenital anomaly characterized by an abnormally short lingual frenum, which may restrict tongue tip mobility, In the neonate and infant, tongue-tie was said to cause difficult breast-feeding, In the older infant, toddler and young child, poor speech has been frequently listed because movement of tongue tip is limit ed. Also as a abnormal tongue position, various orthodontic problems, later mechanical and social manifestations could be developed. Treatment options such as observation, speech therapy, frenotomy and frenectomy have been suggested. The optimal timing for the surgery has not been determined, but early intervention may be appropriate for the children with significant tongue-tie who has the significant potential to speech difficulties and later social and mechanical problems. Sedation is an effective method for incapable of cooperative and the handicapped children, necessary to early intervention. We report three cases, using oral sedation for the frenectomy in young children with severe tongue-tie. After treatments, we could find out sufficient tongue movement and improved speech ability. 설유착증(tongue-tie)은 비정상적으로 짧은 설소대로 인하여 혀의 움직임이 제한되는 것을 의미한다. 영유아에서 심한 설유착증은 수유곤란을 야기하기도 하고, 증상이 지속적으로 존재할 때는 혀의 운동범위가 제한되어 발음문제를 야기할 수 있다. 또한 비정상적인 혀의 위치로 인해 여러 가지 교정적인 문제를 초래 할 뿐만 아니라, 기능적, 사회적 장애요소로 작용할 수도 있다. 설유착증의 치료방법으로는 관찰, 언어치료, 단순절개술 그리고 절제술 등이 있는데, 수술시기에 대한 논란은 있지만 정도가 심하여 장기간 언어장애가 지속되거나 교정적인 문제를 야기 할 것으로 판단되는 경우 조기수술이 권장되고 있다. 진정요법은 조기치료가 필요한 나이가 어리고 비협조적인 환아들이나, 신체적, 정신적 이유로 통상적 인 치과진료에 어려움이 있는 환아들에게 효과적으로 사용될 수 있는 방법이다. 본 증례는 설유착증으로 수술이 필요하나 협조전단계인 환아를 대상으로 경구투여를 이용한 진정요법으로 소대절제술을 시행하여 양호한 결과를 얻었기에 이를 보고하는 바이다.

Bone-supported pendulum을 이용한 상악대구치 원심이동

장용걸,박호원,이주현,서현우 大韓小兒齒科學會 2009 大韓小兒齒科學會誌 Vol.36 No.3

상악 대구치의 원심이동이 요구되는 경우, 구외견인, Wilson distalizing arches, 가철식 스프링 장치 그리고 Schwarz plate-type 장치 등을 사용 할 수 있다. 그러나 이러한 전통적인 대구치의 원심이동 장치들로 치료에 성공하기 위해서는 환자의 협조가 필수적이기 때문에 많은 소아치과 의사들은 환자 의존성을 최소화하고 임상가가 통제 할 수 있는 장치들로 전환하고 있다. 이 중 가장 일반적인 것이 pendulum 장치인데, 고정원이 되는 전방치아의 원하지 않는 이동과 고정원 소실, 그리고 구개부 고정원이 좋지 않은 경우 원하는 정도의 구치부 원심이동을 얻기 어렵다는 단점이 있다. 이와 같은 전통적인 pendulum의 단점을 해결하고자, SAS(Skeletal Anchorage System)를 pendulum에 접목하여 골에서 직접 지지를 얻는 변형된 형태의 pendulum, 즉 bone supported pendulum을 제작하여 장착 시킨 후 주기적인 관찰을 시행하였다. 본 증례는 혼합치열기 환자를 대상으로 bone supported pendulum을 사용하여 안정된 고정원 유지, 원치 않는 치아이동의 최소화 및 양호한 상악 대구치 원심이동 등을 관찰하였기에 이를 보고하는 바이다. To distalize the maxillary molars. the traditional techniques such as extra-oral traction. Wilson distalizing arches. removable spring appliances and Schwarz plate-type appliances have been used. But, these need considerable patient cooperation. For minimal patient compliance. many practitioners use the pendulum appliances. Several clinical studies demonstrated pendulum is effective molar distalization appliance in the growing patient(using the premolars and the palate as anchorage). But unfortunately, maxillary anterior teeth also shift mesially as the molar moves distally. As a result anchorage loss is occurred. To overcome these disadvantages, we used bone-supported pendulum, combined the conventional pendulum with Skeletal Anchorage System(SAS). The miniscrew was implanted in the anterior paramedian region of the median palatal suture, which has comparatively sufficient bone thickness and is low risk to damage on the dental follicles. We report three cases, using bone-supported pendulum for the maxillary molar distalization in children. After treatment, we find out anchorage stability, minimal unfavorable anterior tooth movement and sufficient molar distalization.

이산화된 탐색공간에서 다구찌 방법을 이용한 구조 최적설계에 관한 연구

장성현,정우영,정용민,권봉철,최영휴 한국공작기계학회 2008 한국공작기계학회 추계학술대회논문집 Vol.2008 No.-

Nowadays, there are several design problem having discrete variables in the industrial fields. The researchers are using the optimization method, such as genetic algorithm (GA), simulated annealing (SA), design of experiment (DOE) and taguchi method (TM), to solve it's design problem. Moreover, people want to decrease the computational cost and time. Therefore, in this paper, we proposed the iterative optimization algorithm which repetitively searched a local region to find best solution in discrete searching space using TM. The optimal solution in each local region is obtained by S/N ratio for the evaluation function that consists of the objective function and penalty function. Also, we have applied our algorithm to 3-bar, 10-bar, and 25-bar truss optimization problem.

시멘트 종류별 콘크리트의 적산온도에 의한 강도예측에 관한 연구

장종호,나철성,김재환,김용로,길배수,남재현,김무한 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.2

The purpose of this study is to exhibit fundamental data which can apply to quality and process management of structure concrete using special cement in the construction field investigating strength prediction by maturity method of concrete according to cement types. The activation energy value was derived from the experimental study that experimental factors were selected as W/C ratio of 45%, the kinds of cements of 3 levels of O.P.C, H.B.C, H.S.C and curing temperature of 3 levels of 5℃, 20℃, 35℃. Also, after investigating relationship between compression strength and equivalent ages of concrete according to cement types, the strength prediction was investigated by maturity method. As the above of results, differences between the prediction strength by strength prediction equation and the actual measurement strength were lower, therefore it is considered that the strength prediction by maturity method is possible not only concrete using normal portland cement but also concrete using special cement.