• Restorative Dentistry and Endodontics
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• 제27권2호
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• pp.175-182
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• 2002

Dental caries is a chronic disease that causes the destruction of tooth structure by the interaction of plaque bacteria, food debris, and saliva. There has been attempts to induce remineralization by supersaturating the Intra-oral environment around the surface enamel, where there is incipient caries. In this study, supersaturated remineralized solution "R" was applied to specimens with incipient enamel caries, and the quantitative analysis of remineralization was evaluated using microradiography. Thirty subjects volunteered to participate in this study. Removable appliances were constructed for the subjects, and the enamel specimen with incipient caries were embedded in the appliances. The subjects wore the intra-oral appliance for 15 days except while eating and sleeping. The removable appliance were soaked in supersaturated solution "R", saline, or Senstime$^{\circledR}$ to expose the specimen to those solutions three times a day, 5 minutes each time. After 15 days, microradiography was retaken to compare and evaluate remineralization The results were as the following: 1. The ratio of remineralized area to demineralized area was significantly higher in the supersaturated solution "R" and Senstime$^{\circledR}$ than in the saline (p<0.05) 2. Remineralization in the supersaturated buffer solution "R" occurred in the significantly deeper parts of the tooth. compared to the Senstime$^{\circledR}$ group containing high concentration or fluoride. (p<0.05) As in the above results, the remineralization effect of remineralized buffer solution "R" on incipient enamel caries has been proven. For clinical utilization, further studies on soft tissue reaction and the effect on dentin and cementum are necessary In conclusion compared to commercially available fluoride solution. remineralization solution“R”showed better remineralization effect on early enamel caries lesion, so it is considered as effecient solution for clinical application.

• 대한소아치과학회지
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• 제36권3호
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• pp.420-426
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• 2009

본 연구의 목적은 유치열기 3급 부정 교합 환아에서 facemask를 이용한 악정형 치료 후 골격적 변화와 치료 후 나타나는 재발 양상을 평가하는 것이다. 유치열기 3급 부정교합 환아 15명을 대상으로 구내장치로 bonded expander, 구외장치로 facemask를 이용한 악정형 치료를 평균 12 개월 동안 시행하였으며, 1년 간의 follow-up 기간 동안 유지 장치는 사용되지 않았다. 치료 시작 전, 치료 직후, 치료 1년 후에 측면두부방사선사진을 촬영하고 전후방 및 수직적 골격관계와 연조직의 변화를 비교분석하였다. 모든 환아에서 치료 직후, 유의할 만한 골격적 전후방 관계의 변화를 보였고 1년 간의 follow-up 기간 동안 재발되는 경향을 보였으나 치료 시작 전과 비교하여 치료 효과는 유지되었다. 수직적 골격적 변화는 치료 직후 증가되었으나 1년 간의 follow-up 기간 동안 다시 감소하여 치료 시작 전과 비교하여 차이를 보이지 않았다. 연조직의 변화는 facial convexity 및 상순의 위치가 치료 직후 개선됨을 보였고 1년 간의 follow-up 기간 동안에도 치료 전과 비교하여 치료효과는 유지되었다. 하순의 위치는 치료 직후에 유의할 만한 변화를 보이지 않았다. Facemask는 유치열기 3급 부정교합에 있어서 효과적인 치료 방법이며, 안정적인 치료 결과를 위해서는 적절한 형태의 유지장치가 고려되는 것이 바람직하다.

• 대한치과기공학회지
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• 제31권2호
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• pp.31-38
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• 2009

In recent year, the population for sports has been increased and lots of wounded patients at the oral & facial portion were troubled with the accidents. So, it was needed to protect them from the sports accident, by the use of the mouthguard appliance. This study was done as ae guide for selection of the mouthguard materials. Such mouthguards classified as E.V.A., PE, silicone as material, Scheu(Germany), Tru-Tain(U.S.A.), Dreve(Germany) as companies, 1.5mm, 3.0mm, and 4.0mm as thickness and single sheet, soft double sheet, hard double sheet methods were selected for experiment to compare the fracture protect test. The obtained results are as follows. 1. All types of mouthguards, whatever differences there are in material, production company, procedure and the thickness, were effective for fracture protect effect. 2. The most effective one for fracture protection was recommended as E.V.A. in material, and Tru-Tain in company. 3. More thick, and soft & hard multi sheets productions were more effective for fracture protection.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.1373-1377
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• 2003

Current prostheses for amputees are generally extrinsic wearing socket type that the coupling between body stump and appliance wraps the soft tissue and this structure causes several problems :applying direct weight to soft tissue such as skin and muscle, skin trouble of contacting area and pain. In this study, osseointegration implant is a method to directly connect prosthesis to the residual stump skeletal tissue of arm, finger and leg through surgical operation. Technology presented in this paper essentially solves the problems of pain and abnormal weight transfer system indicated above and recovers the functions of the amputated arm and leg. In this paper, implant shape was designed for the first step for the development of osseointegration implant and then we studied the possibility to apply this osseointegration implant to human body by performing implant insertion operation to beagle tibia for the clinical animal test and normal beagle's gait analysis was executed in order to quantitatively verify the beagle's skeletal functions after the implant insertion.

• 대한치과교정학회지
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• 제24권1호
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• pp.37-62
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• 1994

This study was undertaken to investigate the three dimensional vascular changes of periodontal ligament following orthodontic tooth movement. Experimental tooth movement was carried out in 96 Sprague-Dawley rats with the weight of 250g. They were divided into four experimental groups (each 24 rats). The left maxillary first molar was moved mesially with 25g force in group I, and with 75g force in group II. Each three animals were sacrificed after 1, 6, 12, 24 hours, and 3, 7, 14, 21 days. In group III, 25g mesial force was applied for 3 days, and in group IV, 75g mesial force was applied for 3 days. Then the appliances were removed, and each three animals were sacrificed after 1, 6, 12, 24 hours, and 3, 7, 14, 21 days from removal of appliance. The contralateral molars were used for control group. Casting media was injected via left ventricle and polymerized in warm water. After corrosion of surrounding soft tissue, three dimensional vascular changes were examined using scanning electron microscopy. The findings of this study were as follows: 1. Pressure side of group I and II showed degenerative vascular changes such as vascular compression, reduction of vasculature, leakage of casting media. But, regenerative changes were dominant after 7 days of tooth movement. Although the degenerative vascular changes were more severe in group II, which was exposed to heavy force, the timing of these changes was not different between two groups. 2. Periodontal vasculature was reestablished by the growth of new capillaries and their differentiation and union from the remaining periodontal vessels and vessels of alveolar bone marrow. Although vascular regeneration was more rapid in group I, which was exposed to light force, the vasculature was not fully normalized in both groups even after 21 days. 3. There was no remarkable changes in tension side of group I and II, but looping of capillary, new capillary growth, dilation of vessels, redirection of vessels in the direction of tensile force were occurred. 4. In pressure side of group III and IV, in which appliance was removed after 3 days of orthodontic force, bone resorption was continued even after removal of appliance. Regeneration of vasculature was initiated after 1-6 hours, and it was more rapid in group III than group IV. In both groups, the vasculature was not fully normalized even after 21 days. 5. After removal of appliance, tension side of group III and IV showed vascular compression and loss of vasculature.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2006년도 춘계학술대회 논문집
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• pp.387-390
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• 2006

This paper presents a novel soft-switching PWM utility frequency AC to high frequency AC power conversion circuit Incorporating boost-half-bridge inverter topology, which is more suitable and acceptable for cost effective consumer induction heating applications. The operating principle and the operation modes are presented using the switching mode and the operating voltage and current waveforms. The performances of this high-frequency inverter using the latest IGBTs are illustrated, which includes high frequency power regulation and actual efficiency characteristics based on zero voltage soft switching (ZVS) operation ranges and the power dissipation as compared with those of the previously developed high-frequency inverter. In addition, a dual mode control scheme of this high frequency inverter based on asymmetrical pulse width modulation (PWM) and pulse density modulation (PDM) control scheme is discussed in this paper in order to extend the soft switching operation ranges and to improve the power conversion efficiency at the low power settings. The power converter practical effectiveness is substantially proved based on experimental results from practical design example.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.896-897
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• 2008

홈넷기반 정보가전기기의 대기전력을 초절전칩을 적용하여 1W 이하로 줄이고, 가전기기에서 낭비되는 전력의 경로를 오토스위치를 통해 전력소모를 차단시키며, 홈플러그와 관리서버를 통해 전력낭비의 요소를 파악하여 전력소모를 저감하여 안전하고 쾌적한 홈오토메이션을 구현함으로써 인류의 행복추구를 목적으로 한다.

• The Journal of Advanced Prosthodontics
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• 제4권4호
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• pp.243-247
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• 2012

The velopharynx is a tridimensional muscular valve located between the oral and nasal cavities, consisting of the lateral and posterior pharyngeal walls and the soft palate, and controls the passage of air. Velopharyngeal insufficiency may take place when the velopharyngeal valve is unable to perform its own closing, due to a lack of tissue or lack of proper movement. Treatment options include surgical correction, prosthetic rehabilitation, and speech therapy; though optimal results often require a multidisciplinary approach for the restoration of both anatomical and physiological defect. We report a case of 56 year old male patient presenting with hypernasal speech pattern and velopharyngeal insufficiency secondary to cleft palate which had been surgically corrected 18 years ago. The patient was treated with a combination of speech therapy and palatal lift prosthesis employing interim prostheses in various phases before the insertion of definitive appliance. This phase-wise treatment plan helped to improve patient's compliance and final outcome.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2008년도 추계학술대회 논문집
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• pp.150-153
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• 2008

This paper presents soft-switching boost converter adding to auxiliary switch and resonant circuit in conventional boost converter. This approach features a two power stage which implements both conventional BLDC motor speed control and input power factor correction. This converter is especially useful in application such as home appliance. Theoretical analysis and simulation results are presented.

• 대한소아치과학회지
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• 제36권1호
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• pp.108-113
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• 2009

Functional regulator라고 불리는 $Fr{\ddot{a}}nkel$ appliance는 악안면 발육을 방해하는 비정상적인 근육의 활동을 차단하여 치열 및 악궁에 대한 힘의 불균형을 개선하고 구강 주위 근육을 훈련시켜 새로이 형성된 힘의 균형에 의해 이차적으로 악안면골의 형태 및 크기를 변화시킨다고 알려져 있다. 다른 기능적 악정형 장치물(트윈 블록, 바이오네이터, 액티베이터)과는 달리 $Fr{\ddot{a}}nkel$ 장치는 성장을 조절하는 능력이 연조직에 있고, 적당한 공간은 경조직의 발육에 유용하다는 개념을 갖는 것이 특징 적이다. 하악의 골격성 후퇴가 특징인 II급 부정교합에서 FR-II가 선택될 수 있으며, FR-II를 이용하여 하악의 자세적 위치 변화를 유발하는 것은 물론 악궁의 확대 효과 또한 기대할 수 있다. 근신경 환경의 조화에 의하여 심한 부정교합은 성공적으로 치료될 수 있을 뿐만 아니라 재발의 경향도 감소된다. 본 소아치과에 내원한 II급 부정교합 환자를 대상으로 고정성 장치의 치료없이 FR-II와 space supervision만을 적용하여 성공적인 개선을 보인 몇 가지 증례들을 보고하고자 한다.