• The korean journal of orthodontics
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• v.35 no.1 s.108
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• pp.82-89
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• 2005

Mandibular widening is one method of mandibular distraction osteogenesis, which has anatomic limitations such as curved surface, mandibular condyle and narrow arch. The purpose of this study was to understand the biomechanics of various mandibular widening procedures Experimental models consisted of 6 groups according to different osteotomy hues and distractor positions. The results of this study showed different expansion patterns. which meant the feed for proper approaches in mandibular widening.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.05a
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• pp.265-269
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• 2005

본 논문에서는 최대 견인력 제어를 위해서 최소 차원 부하 토크 외란 관측기를 이용하여 점착력 계수를 추정하고 추정한 점착력 계수의 미분치를 PI 토크 제어하는 Anti-slip제어를 제안한다. 최소차원 부하 토크 외란 관측기는 회전자의 위치 정보와 토크 전류의 정보를 이용하여 부하 외란토크를 추정하고, 부하 외란 토크에 철도차량 상수를 이용하여 점착력 계수를 추정한다. 또한 부하토크외란 관측기는 구조가 간단하며, 시스템의 외란 및 각종 제어이득, 시스템의 상수 변화에 대해서도 견실한 견인력 제어 특성을 가지고 있다. 이와 같은 시스템의 모델링과 전동기 토크에 대한 회전자의 위치 정보를 이용하여 최소차원 부하 토크 외란 관측기의 상태변수인 점착력 계수를 추정하고, 추정한 점착력 계수의 미분치를 PI토크 Anti-Slip제어하여, 최대 견인력 제어가 되도록 하였다.

• Journal of Korean Society of Transportation
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• v.21 no.3
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• pp.143-156
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• 2003

도시로의 집중현상에 따라 차량이 증가함으로 한정된 공간에서의 도시교통난이 계속 악화되고 있는 실정이다. 도로상의 불법 주ㆍ정차위반차량으로 인해 차량소통에 불편을 주고, 주거 및 교통환경을 저해하기 때문에 견인업무는 주차정책을 실현시키는 강력한 수단으로써 반드시 필요하지만, 우리나라에서 불법 주ㆍ정차 차량의 견인부분에 대한 연구 및 결과는 극히 미비한 실정이다. 이에 따라 본 연구에서는 우리나라 주요 도시를 대상으로 불법 주ㆍ정차 차량의 견인운행 실태 및 특징을 비교, 견인제도의 문제점을 분석하여 개선방안을 검토하고자 하였다. 이의 내용으로는 각 시에서 추진 및 계획중인 지능형 교통체계(ITS), 버스 정보시스템(BIS) 및 차량 위치 자동 표시기(AVM)를 연계시켜 공차거리를 줄이는 등의 첨단체계를 구축하여 견인차량에 대한 운영을 효율적으로 하여야 할 것이고, 요금의 구조도 서울을 제외한 기존의 3단계 톤급별 요금구조에서 장래 대형차의 견인을 감안한 4단계의 톤급별 요금구조로의 조정방안이 필요하다. 견인비용에 있어서도 대부분의 도시가 수년전의 여건을 근거로 산출한 결과를 기준으로 요금을 징수하고 있어 현실에 맞지 않는 요금체계를 적용시키고 있는 실정이다. 따라서, 견인비용부분에 대하여도 장래의 경제여건을 감안한 탄력적 요금체계를 설정하여 경영합리화를 유도함이 바람직하다. 부가하여, 견인원가에 대한 사례분석 결과는 부천시를 중심으로 하여 현실성 있는 견인비용을 제시코자 하였다.

• The Transactions of the Korean Institute of Power Electronics
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• v.8 no.4
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• pp.366-374
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• 2003

In electric motor coaches, the rolling stocks move by the adhesive effort between rail and driving wheel. Generally, the adhesive effort is defined by the function of both the weight of electric motor coach and the adhesive effort between rails and driving wheel. The characteristics of adhesive effort is strongly affected by the conditions between rails and driving wheel. When the adhesive effort decreases suddenly, the electric motor coach has slip phenomena. This paper proposes a re-adhesion control algorithm which uses the maximum adhesive effort by instantaneous estimation of adhesion force using load torque disturbance observer. Based on this estimated adhesive effort, the re-adhesion control Is peformed to obtain the maximum transfer of the tractive effort.

• The Journal of the Acoustical Society of Korea
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• v.20 no.5
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• pp.83-91
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• 2001

This paper proposes the Focused beamforming to estimate the location of target residing near to the observation platform in the underwater environment. The Focused beamforming technique provides the location of target by the coherent summation of a series of incident spherical waveforms considering distinct propagation delay times at the sensor array. But due to the movement of the observation platform and the variation of the underwater environment, the shape of the sensor array is no longer to be linear but it becomes distorted as the platform moves. Thus the Focused beamforming should be peformed regarding to the geometric shape variation at each time. To estimate the target location, the artificial image plane comprised of cells is constructed, and the delays are calculated from each cell where the target could be proximity to sensors for the coherent summation. After the coherent combining, the beam pattern can be obtained through the Focused beamforming on the image plane. Futhermore to compensate the variation of the shape of the sensor array, the paper utilizes the Nth-order polynomial approximation to estimate the shape of the sensor array obeying the water pulley modeling. Simulation results show the performance of the Focused beamforming for different frequency bands of the radiated signal.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.72-72
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• 2017

국내 농업에서 토양의 반전, 쇄토, 배토, 가능한 복합작업기인 무동력 디스크해로우 방식의 경운과 배토 고효율 복합작업기의 수요가 증가 하고 있다. 경운작업에서 일련의 과정은 작물의 생육과 관리차원에서 큰 의미를 지니며 작물재배의 첫 단계로 중요시 다루어져야할 과정이다. 이러한 작업기의 성능 시험에서 포장시험을 통해 복합기의 신뢰도와 실제 필드에서 발생하는 문제들을 포괄적으로 해결 할 수 있는 방안이 필요하다. 토양 경작을 위한 농업기기의 작업 저항은 식물 생산에서 유용성을 평가하는 가장 중요한 지표중 하나이다. 작업 저항(수평, 수직 방향의 힘)은 트랙터의 힘에 의해 생성된 동작을 방해하므로 토양 경운 시 에너지 소비를 결정하고 설계 매개 변수 측면에서 최적의 작업 조건을 결정하는 데 중요한 영향을 미친다. 따라서 본 연구에서는 경상대학교 내 위치한 실험동에서 Soil-bin에 이송장치를 설치한 후, 이송장치에 디스크 해로우 (Multidisc Vario, Tulip Agri., Netherlands)를 부착하여 실험을 진행하였다. 디스크 해로우의 원주 평면과 수직 평면 사이의 각 a(토양 표면에 수직)와 디스크의 해로우의 원주 평면과 작업 방향 사이의 각 b의 값을 독립 변수로 두고 a, b를 변화 시키면서 발생하는 이송장치의 견인력을 측정하여 농가 및 효율적인 경운작업 시 기초자료로 활용하고자 한다.

• Journal of the korean academy of Pediatric Dentistry
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• v.38 no.4
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• pp.435-440
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• 2011

Maxillary canine impaction is a common eruption problem in children. Impaction frequently involves further complications such as root resorption of adjacent teeth, cyst formation and migration of the neighboring teeth, etc. Various treatment modalities include extraction of preceding deciduous canine, orthodontic traction, and surgical extraction followed by immediate replantation of the extracted tooth at the proper position(autotransplantation). Autotransplantation is considered as the treatment of choice when surgical exposure and subsequent orthodontic traction are difficult or impossible due to unfavorable impacted position. The prognosis of autotransplantation is affected by the degree of apex formation, surgical procedures performed, timing of root canal treatment, and length of stabilization period. In these two cases presented, the patients with unerupted maxillary canine were treated with autotransplantation. One case was thought that guidance of eruption by orthodontic traction was difficult because of its unfavorable impacted position. In the other case, parents didn't agree to treat by orthodontic traction, therefore autotransplantation was done. In both cases, autotransplantation was carried out following root canal treatment and orthodontic treatment, and both cases have demonstrated to be successful to this day.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.3
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• pp.409-415
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• 2005

Impaction of permanent incisor occurs rare than the canine & third molar. But it's often observed in school age child. The causes of impaction are trauma, space deficiency, mesiodens, infections of root apex, etc. In spite of elimination of cause, normal eruption of impacted tooth is rare. Though eruption is normal, the position of tooth will be incorrect. Because the impacted tooth results in malocclusion, root resorption of adjacent tooth, pathologic cystic change, it should be confirmed the precise position by clinical and radiographic exam and found the correct location by appropriate treatment plan. In case of pathologic change of impacted tooth and injury to adjacent tooth, it will be extracted. But through orthodontic retraction, the function and esthetics of tooth can be restored. It is important that impacted tooth should be detected early and diagnosed correctly, and appropriate treatment plan should be made. Before impacted tooth is retracted, the considerations of space for alignment and anchorage should be preceded and through appropriate force and mechanics, the side effects, for example, a root resorption should be minimized. In this study, we guided impacted tooth to normal position by using a forced eruption.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.4
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• pp.709-717
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• 2007

Impaction of maxillary incisor is rare than the third molar and canine, but its rate is higher than the other anterior teeth due to frequent mesiodens, trauma and variation of root formation (root dilaceration etc.). It is often observed in the dental age of about eight years and over. It will be occurred that the space loss, midline deviation and cyst formation due to the impaction of maxillary incisor. So it is important to evaluate the precise location of impacted tooth and to make appropriate treatment plan. Treatment would be surgical extraction or expectation for spontaneous eruption. If the impacted tooth has no pathologic change and development of the root is favorable, orthodontic traction is recommended for recovery of function and esthetics. In these cases, we performed orthodontic traction for the eruption of impacted maxillary incisors, and obtained satisfactory results.

• Journal of the Korean Arthroscopy Society
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• v.14 no.1
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• pp.49-52
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• 2010

Purpose: We introduce arthroscopically assisted mini-open rotator cuff repair using anterolateral approach. Operative Technique: Placing lateral decubitus position on general anesthesia, a standard arthroscopic glenohumeral examination is performed to evaluate lesions of shoulder joint through posterior and anterior portal. And then arthroscope is placed in the subacromial space and we evaluate the size of the torn tendon and perform arthroscopic acromioplasty through lateral portal. A 3 to 4 cm skin incision is performed from anterolateral edge of acromion to distal and dissected along to raphe between anterior and middle deltoid. A deltoid retractor is then placed, allowing direct visualization of the rotator cuff and humeral head. As torn tendon is tagged by traction suture, we try to anatomical reduction on the footprint and then perform single row or double row repair of the rotator cuff using suture anchors. To prevent avulsion of the deltoid from the acromion, additional sutures by bone tunnel with acromion and deltoid is performed. Conclusion: This technique is useful procedure to get direct approach to anterior portion of supraspinatus tendon and to need lesser deltoid retraction than portal extension approach due to dividing along to raphe between anterior and middle deltoid. Also it provide better visualization of the superior portion of subscapularis and infraspinatus.