• 대한전자공학회논문지SD
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• 제40권2호
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• pp.126-136
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• 2003

본 논문에서는 최근 많은 연구대상이 되고 있는 oscillation test methodology (OTM)의 파라메트릭 고장에 대한 커버리지를 높일 수 있는 방법을 제안한다. OTM은 테스트 입력신호가 별도로 필요없는 장점으로 인해 효율적인 built-in self test (BIST) 기술로서도 많은 관심의 대상이 되어 왔다. 그러나 아직 여러 가지 면에서 좀더 연구개발이 필요한 상태이며, 따라서 본 논문에서는 그 성능을 향상시킬 수 있는 방안을 제안한다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 추계학술대회 논문집
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• pp.579-580
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• 2010

• 한국산학기술학회논문지
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• 제15권8호
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• pp.5233-5241
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• 2014

본 논문에서는 Mobile WiMAX 기반 군전술정보통신네트워크 (TICN)의 성능을 시스템 레벨에서 평가한다. 전시에 정지상태의 기지국 (BS: Base Station)들이 불규칙적으로 분포되어 있는 환경에서 이동 기지국 (BS-OTM)이 투입되었을 때 인접 기지국 및 가입자 (SS: Subscriber Station)가 받는 영향을 분석한다. 이동기지국이 추가적으로 사용되었을 때 서비스를 제공하는 기지국이 변함없는 가입자 관점에서는 간섭이 증가하여 CINR(Carrier To Interference and Noise Ratio)이 감소하고 이동 기지국에 의해 가입자가 두 기지국으로 분산되어 다중사용자 다이버시티가 감소하는 단점이 있음을 밝힌다. 그러나 통신 환경이 열악했던 가입자 주변에서 이동 기지국이 작동하게 되어 새롭게 서비스 받게 되는 가입자들은 큰 CINR 이득을 얻게 되며, 셀 전체적인 수율관점에서는 이동기지국에 의해 성능이 크게 향상된다. 또한, 반송파주파수, 이동기지국의 이동속도 및 위치에 따른 성능을 평가한다.

• 한국통신학회논문지
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• 제39C권9호
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• pp.757-766
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• 2014

본 논문에서는 차기 군 위성통신체계 환경에서 OTM(On-The-Move) 위성단말의 채널 blockage 신호 손실 보상을 위한 협업통신 기법을 제안하였다. 제안하는 협업기법은 인접 OTM 위성단말과 지상 무전기 체계를 통해 데이터를 공유하고 직교확산코드를 이용하여 대역확산 후 동시에 전송한다. 중첩되어 전송된 확산열은 EGC(Equal Gain Combining) 방식으로 결합한다. 성능 분석을 위해 OTM 위성단말의 blockage 채널을 2-state Markov chain으로 모델링하였으며, 이를 기반으로 협업단말들의 blockage 채널 상태에 따른 비트오류율을 도출하였다. 성능분석 결과 채널 조건이 더 나은 인접 OTM 위성단말의 협업으로 비트오류율 성능이 향상됨을 확인할 수 있었다. 특히 blockage 확률이 높을수록 협업을 통해 더욱 우수한 성능을 확인할 수 있었다. 그러나 서로 다른 지연을 갖는 확산 열 간 중첩으로 인해 협업단말 수 증가 시 다중접속간섭으로 인한 성능상의 제약이 있음을 확인하였다.

• 대한치과의사협회지
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• 제51권3호
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• pp.138-147
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• 2013

Orthodontic tooth movement is a unique process which tooth, solid material is moving into hard tissue, bone. Orthodontic force in general provides the strain to the PDL and alveolar bone, which in turn generates the interstitial fluid flow(in detail, fluid flow in PDL and canaliculi). As a results of matrix strain, periodontal ligament cells and bone cells are deformed, releasing variety of cytokines, chemokines, and growth factors. These molecules lead to the orthodontic tooth movement(OTM). In these inflammation and tissue remodeling sites, all of the cells could closely communicate with one another, flowing the information for tissue remodeling. To accelerate the rate of OTM in future, local injection of single growth factor(GF) or a combination of multiple GFs in the periodontal tissues might intervene to stimulate the rate of OTM. Corticotomy is effective and safe to accelerate OTM.

• 한국소음진동공학회논문집
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• 제21권10호
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• pp.951-959
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• 2011

In this study, an OTM(on-the-move) antenna which is mounted on ground vehicles and is used for mobile communication between vehicle and satellite while moving was addressed. Since LOS(line-of-sight) of antenna should direct satellite consistently while vehicle moving to guarantee high satellite communication quality, active antenna LOS stabilization is a core technology for OTM antenna. Stabilization of a satellite tracking antenna which consists of 2-DOF gimbals, an elevation gimbal over an azimuth gimbal, was considered in this study. In consideration of driving mechanism which consists of gear train and flexible driving shafts, a two-mass-system dynamic model coupled with vehicle motion was presented. An internal PI-control loop + outer PI-control loop structure has been suggested in order to damp the torsional vibration and stabilize control system. The classical pole-placement method was applied to design control gains. In addition, a vehicle motion compensation control beside of the feedback control loop has been suggested to improve LOS stabilization performances. The feasibility of the proposed control design was verified along with some experimental results.

• 대한치과교정학회지
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• 제54권1호
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• pp.3-15
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• 2024

The prevalence of intrabony defects in patients with advanced periodontitis stages III and IV is high. These patients usually need both periodontal treatment and orthodontic therapy, including tooth movement through bone defects, to improve masticatory function, aesthetics, and overall quality of life. Clinical practice guidelines recommend periodontal regenerative surgical interventions to resolve these defects and propose initiating orthodontic tooth movement (OTM) once periodontal therapy goals have been met. Surgical interventions using various regenerative technologies like barrier membranes and enamel matrix proteins, combined or not with bone replacement grafts, have proven effective in regenerating lost periodontal tissues. However, the combination of periodontal and orthodontic treatments requires consideration of how periodontal regenerative therapies influence OTM. Studies suggest that regenerated bone may differ in density, composition, vascularity, and cellular activity, potentially affecting the speed and efficiency of OTM, and potential root resorption of moved teeth. Understanding the sequence and timing of implementing OTM after regenerative periodontal interventions is crucial due to their interlinked processes of bone resorption and formation. This narrative review aims to uncover scientific evidence regarding these combined treatments, examining the impacts of different regenerative technologies on OTM and delineating their advantages, limitations, and best practices.

• 전기학회논문지
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• 제59권11호
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• pp.2073-2082
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• 2010

The 4-th generation of mobile communication aims to realize global, fast and mobile communication service. The satellite communication charges a key role in this field. In this study, an OTM(On-The-Move) antenna which is mounted on ground vehicles and is used for mobile communication between vehicle and satellite was addressed. Since vehicles move during communication, active antenna line-of-sight stabilization is a core technology to guarantee high satellite communication quality. Stabilization of a satellite tracking antenna which consists of 2-DOF gimbals, an elevation gimbal over an azimuth gimbal, was considered in this study. Various disturbance torques such as static and dynamic mass imbalance torques, variation of moment of inertia according to elevation angle, friction torque related to vehicle motion, equivalent disturbance torque due to antenna roll motion, etc. were analyzed. As a robust stabilization control, rate feedback with sliding mode control and position feedback with proportional+integral control was suggested. To compensate antenna roll motion, a supplementary roll rate feed forward control was included beside of the feedback control loop. The feasibility of the analysis and the proposed control design were verified along with some simulation results.

• 한국통신학회논문지
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• 제40권1호
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• pp.1-8
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• 2015

본 논문에서 제안된 OTM(On-The-Move) 위성통신 시스템은 차량에 탑재하여 주행중에도 위성통신을 제공하기 위해 다중모드 모노펄스 추적 방식을 사용한다. 이 방식에서는 저잡음 증폭기(Low Noise Amplifer)가 2개의 입력과 2개의 출력을 가지는 것이 기본 설계 구조이나, 본 논문에서는 OTM 위성통신 시스템의 소형 경량화를 위해 저잡음 증폭기 내에 하향변환부를 추가한 출력채널 단일화 구조를 제안한다. 그러나 출력 채널 단일화 구조에서는 기본모드와 고차모드 경로에서 시간에 따른 위상 차이의 변화가 발생하므로 저잡음 증폭기내에 파일럿 신호를 추가하여 파일럿 신호 위상차와 비교함으로써 시간에 따른 위상 변화를 제거하는 방안을 제시하고 주행시험을 통해 검증한다.

• 대한치과교정학회지
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• 제51권4호
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• pp.282-292
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• 2021

Objective: To quantitatively analyze the effect of nicotine on orthodontic tooth movement (OTM) and bone remodeling in rats using micro-computed tomography and tartrate-resistant acid phosphatase immunostaining. Methods: Thirty-nine adult male Sprague-Dawley rats were randomized into three groups: group A, 0.5 mL normal saline (n = 9, 3 per 3, 7, and 14 days); group B, 0.83 mg/kg nicotine (n = 15, 5 per 3, 7, and 14 days); and group C, 1.67 mg/kg nicotine (n = 15, 5 per 3, 7, and 14 days). Each animal received daily intraperitoneal injections of nicotine/saline from the day of insertion of identical 30-g orthodontic force delivery systems. A 5-mm nickel-titanium closed-coil spring was applied between the left maxillary first molar (M1) and the two splinted incisors. The rate of OTM and volumetric bone changes were measured using micro-computed tomography. Osteoclasts were counted on the mesial alveolar bone surface of the distobuccal root of M1. Six dependent outcome variables, including the intermolar distance, bone volume fraction, bone mineral density, trabecular thickness, trabecular volume, and osteoclast number, were summarized using simple descriptive statistics. Nonparametric Kruskal-Wallis tests were used to evaluate differences among groups at 3, 7, and 14 days of OTM. Results: All six dependent outcome variables showed no statistically significant among group-differences at 3, 7, and 14 days. Conclusions: The findings of this study suggest that nicotine does not affect OTM and bone remodeling, although fluctuations during the different stages of OTM in the nicotine groups should be elucidated in further prospective studies.