온도 변화가 교정용 니켈-티타늄 호선의 하중값에 미치는 영향

천경애,임성훈,김광원 대한치과교정학회 2007 대한치과교정학회지 Vol.37 No.6

초탄성 니켈-티타늄 호선의 하중값은 온도 변화에 따라 변화함이 보고된 바 있다. 따라서 본 연구에서는 온도가 변화함에 따라 니켈-티타늄 합금 호선의 하중값이 어떻게 변화하는지 알아보고자 하였다. 37℃ 항온 상태에서 0.016" x 0.022" 니켈-티타늄 호선을 3.1mm까지 변위시키는 3점 굴곡 실험을 시행하여 하중 시와 탈하중 시의 1.5mm 변위지점의 하중값을 측정하고 이 지점에서 구강내 온도 변화를 고려한 온도 변화 실험을 시행하였다. 20℃ 저온수 또는 50℃ 고온수를 호선에 흘려보냄으로써 온도 변화를 주었다. 저온 실험은 저온수로 온도 변화를 주고 37℃ 항온 온도로 회복된 후에 다시 저온수를 흐르게 하는 방법으로 10회 시행하였고 고온 실험도 동일한 방법으로 시행하였다. 그 결과 하중 시 1.5mm 변위지점의 하중값은 저온 실험 및 고온 실험 후 37℃로 회복된 후에도 모두 감소된 값을 유지하였다. 반대로 실제로 치아에 가해지는 교정력으로 생각되는 탈하중 시 1.5mm 변위 지점의 하중값은 저온 실험 및 고온 실험 후 온도가 37℃로 회복되어도 모두 증가된 값을 유지하였다. 이상의 결과를 종합해 볼 때 온도변화를 거친 후 초탄성 니켈-티타늄 합금 호선의 하중 시 힘은 감소하였고 탈하중 시 힘은 증가되므로, 임상에서 니켈-티타늄 호선을 적용 시에는 37℃에서의 하중-변위 곡선에서 나타나는 힘에 비해 더 작은 하중 시 힘과 더 큰 탈하중 시 힘이 적용될 수 있음에 유의하여야 한다. Objective: The purpose of this study was to evaluate the influence of intraoral temperature changes on the orthodontic force level of a superelastic nickel-titanium alloy wire. Methods: Nickel-titanium archwires of 0.016" x 0.022" thickness were tested with a three point bending test setup, and temperature changes were applied. The force level changes according to temperature changes were measured at a 1.5mm deflection during the loading phase and a 1.5mm deflection during the unloading phase from a deflection to 3.1mm. Ten cycles of thermal cycling from baseline (37℃) to cold (20℃) or hot (50℃) temperature were applied. Results: After thermal cycling, the force level during the loading phase decreased and the force level during the unloading phase increased even after the temperature was changed to the initial 37℃. Conclusions: The results suggest that the orthodontic force level can not return to the initial force level after temperature changes. When applying superelastic nickel-titanium archwires, we must consider that a lighter force than the loading force and a heavier force than the unloading force will be applied after intraoral temperature changes caused by eating and drinking.

유도 전동기를 위한 자기 동조 퍼지 제어기 설계

전광호,하남수,박준열,김상윤 弘益大學校 科學技術硏究所 1998 科學技術硏究論文集 Vol.9 No.2

The conventional PI control, that are used in the control loop for outer speed of the induction motor, also has difficulty dealing with the dynamic speed tracking, parameter variation, and the load disturbance. As a result, the motion control system operates with a poor performance in the motor´s low speed range. In this paper, a novel speed control system that implements the fuzzy logic controller(FLC) is proposed. The proposed FLC used the speed error, its rate of change, and the drive current as three fuzzy variables. The real command output current is chosen by the defuzzification of the fuzzy output extracted from the fuzzy control rules. The flux and the torque of the induction motor are estimated using the dynamic model with an excellent dynamic response over a wide speed range and with the rotor flux field-oriented scheme of the decoupling characteristics. The performance of this control system is substantiated by computer simulations.

Mesh형 내부전극을 사용한 2중 원통형 오존발생기의 온도 의존특성

전병준,이상근,송현직,박원주,이광식 영남대학교 공업기술연구소 1999 工業技術硏究所論文集 Vol.27 No.1

Nowadays, environment pollution caused by development of industrial society becomes a serious social problem. So, ozonized gas is suggested as a counter plan against the problem. In this paper, a double cylindrical type ozonizer has been designed and manufactured to improve ozone yield by cooling external electrode. The ozonizer equipped with three electrodes(central, internal and external electrodes) and two gaps. Discharge and ozone characteristics are described in this paper by varying flow rate( Q ) of oxygen suppling gas, temperature of cooling gas and supplied voltage.

소배양법으로 배양한 생쥐췌장 베타세포의 형태학적 검정

유광성,전현우,박주홍,윤지원,고광삼 朝鮮大學校 附設 醫學硏究所 1986 The Medical Journal of Chosun University Vol.11 No.1

생쥐췌장 베타세포를 보다 순수하게 배양하기 위해 변형 고안한 소배양법을 검정하였다. 이 소배양법에 있어서는 96well plate에 islet cell을 이식하고 decantation한 다음 thimerosal에 노출시켜 많은 viable cell을 얻을 수 있었고, 생후 7일째의 생쥐의 췌장베타세포의 생존율이 가장 높았다. 또 이 소배양법으로 배양한 생쥐췌장 베타세포들은 위상차현미경, FITC-labelled anti-insulin antibody 염색 및 전자현미경으로 검정한 결과 형태학적으로 정상이었다. 기계적 선택방법으로서 생쥐췌장 베타세포의 decantation 최적시간은 세포를 이식한 후 12∼15시간 이었으며, 화학적 선택방법으로 0.6∼0.8㎍/㎖의 thimerosal에 노출시켜 fibroblastoid cell로 부터 생쥐췌장 베타세포의 분리를 증가시킬 수 있었으며, 두가지 방법을 동시에 응용하여 더 좋은 효율을 얻을 수 있었다. 또 이 소배양법에 있어서 cell duplication은 배양후 36시간후에 2배, 72시간후에 3배가 되었으며, 평균 generation시간은 46.8±7.0시간 이었다. 이들 결과로 미루어 보아 이소배양법은 생쥐췌장 베타세포 배양의 유용한 방법으로서, 췌장 베타세포에 연관된 각종 연구에 이용할 수 있을것으로 사료된다.

코크스 제조 및 사용 공정에서의 코크스오븐 배출물질 연구

이종천,안규동,조광성,이병국 한국산업위생학회 2001 한국산업보건학회지 Vol.11 No.2

This study was performed to evaluate the coke oven emissions (COE) and polynuclear aromatic hydrocarbon levels in coke manu- facturing industry, secondary lead smelting industry and glass bottle manufacturing industry. 1. There were no significant difference between the means of personal samples and area samples by the types of industry(p>0.05). The levels of airborne total particulates of the secondary lead smelting industry was the highest(2.30㎎/㎥), and those of the coke manu- facturing industry and glass bottle manufacturing industry were 1.95 ㎎/㎥ and 1.37 ㎎/㎥. The concentration of COE was the highest in the glass bottle manufacturing industry(0.79 ㎎/㎥), and in order of 0.19㎎/㎥ in the coke manufacturing industry and 0.05 ㎎/㎥ in the secondary lead smelting industry. COE/total particulates(%) was highest in the glass bottle manufacturing industry(58.1%) and in order of 10.3% in the coke manufacturing industry and 3.1% in secondary lead smelting industry. There were significant differences in the total particle concentration and Coe by the types of industry(p<0.05) 2. The levels of airborne total particulates was the highest at the smelting process of secondary lead smelting industry(2.30±0.72 ㎎/㎥), and the lowest at the smelting process of glass bottle manufacturing industry (0.99±1.22㎎/㎥) Concentration of COE was the highest at the casting process of glass bottle manufacturing industry (1.09±1.15㎎/㎥), the lowest at the smelting process of secondary lead smelting industry(0.06±0,03 ㎎/㎥). The COE/total particulates(%) was the highest at the casting process of glass bottle manufacturing industry(65.9±20.5%), and the lowest at the smelting process of secondary lead smelting industry(3.1±2.7%). 3. There were positive correlations between level of The airborne total particulates and concentration of COE in COKE manufacturing industry and glass bottle manufacturing industry(p<0.05), but negative correlation in secondary lead smelting industry. 4. The numbers of case and rates that over the Threshold Limit Values(TLVs) were 24 (77.4%)cases in glass bottle manufacture, 14(23.7%) cases in the coke manufacturing industry and no one case in secondary lead smelting industry. Total numbers of case and rates that over TLVs were 38(35.5%) cases. 5. The limit of detection(LOD) for PAH was 10 ㎍/㎖) in standard sample. All PAH levels of the cokes manufacturing industry and the secondary lead smelting industry and the glass bottle manufacturing industry were trace or not to detect.

한글 문서 구조 분석에 관한 연구

우성준,김광호,유명춘,하진영 강원대학교 정보통신연구소 2008 정보통신논문지 Vol.12 No.-

Although information technology has been developed fast, large amount of machine printed document images are not properly handled due to immature document layout analysis techniques. Previous research has focused on character recognition itself to improve character recognition accuracy. Recently, however, some efforts are made to analyze complex document layout automatically. In this paper, we propose document layout analysis and understanding method for various Hangul document images. Skew detection is performed using projection profile and connected component layout information. Top-down and bottom-up methods are combined to analyze document layout. After text region and non-text region determination, table is further processed to extract row, column, and cell position. We got very high performance for skew correction, zone detection, and table processig from experiments with various Hangul document images.

정형외과 영역에서 Pefloxacin의 임상적 고찰

이광진,안상로,진영안,류천환 최신의학사 1991 最新醫學 Vol.34 No.1

전격성 경과를 취한 만성 호산구성 폐렴 환자 1예

윤호상,진춘조,유광하,이상엽,이수인,정상만,김선두,이순제,이길도,전혜정 건국대학교 의과학연구소 2000 건국의과학학술지 Vol.10 No.-

Chronic eosinophilic pneumonia(CEP) is a rare disease of unknown etiology characterized by chronic infiltration of the lung with eosinophils. It presents with profound systemic symptoms comprising fever, night sweats, weight loss, dyspnea and blood eosinophilia with nonsegmental air-space consolidation confined to the outer third of the lung, the "photographic negative of pulmonary edema". Histopathologic features of chronic eosinophilic pneumonia are intraalveolar and interstitial infiltrations with eosinophils, histiocytes, giant cells, scattered lymphocytes and plasma cells. Glucocorticoid therapy cause prompt resolution of symptoms as well as disappearans of blood eosinophils, elevated serum Ig E levels and the roentgenographic lesions. Infrequent radiographic findings include nodular infiltrates, consolidations, cavitations, atelectasis and pleural effusions. Deaths from CEP although rare, have been reported, but the majorities of CEP have benign courses and do not need a therapy with ventilator. We report a case of chronic eosinophilic pneumonia, which had a sudden course associated with diffuse pneumonic consolidations on the both lung and bilateral pleural effusion.

화상환자에서 혈청중 가용성 Interleukin-2 Receptor의 변동

이희성,이유진,이종량,백광진,하재성,전건수 大韓成形外科學會 1991 Archives of Plastic Surgery Vol.18 No.2

Cell-mediated immunity frequently becomes severely impaired after burn. However, the cause of postburn immune dysfunction is unclear and controversy exists over both pathophysiology and clinical relevance of these abnormalities. This study was undertaken to invstigate the immune responses in vivo of patients with burn. Levels of soluble IL-2R, a sensitive marker of T-cell activation, were measured in 26 patients with burn. Serum soluble IL-2R levels in patients with burn were significantly higher than those of normal controls. Serum soluble IL-2R levels were correlated closely with the severity of the burn. The burn patients were classified according to the outcome. Patients with fatal outcom always showd a higher soluble IL-2R levels than survivors. Postburn sera significantly suppressed mitogen-indeced lymphocyte proliferation. These data indicate that soluble IL-2R might be useful parameters for monitoring of the clinical course in burn patients.

ATM망에서 Fair Queueing 알고리즘에 관한 연구

문규춘,김훈,한상엽,박광채 조선대학교 에너지.자원신기술연구소 1999 에너지·자원신기술연구소 논문지 Vol.21 No.2

B-ISDN using ATM should provide QoS of various service and also fair control for each source. In this paper, we suggested the Virtual-Time-based Round Robin(VTRR), fair scheduling algorithm guaranteeing demanded QoS. We searched the characteristic and required points possessing proper fair scheduling algorithm in high speed network. And we analyzed the performance character and simulation. The result is that VTRR is much simpler in algorithm and is better than WFQ or GPS in performance.