• Archives of Plastic Surgery
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• 제35권1호
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• pp.78-85
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• 2008

Purpose: The capsular contracture has been the most common complication of augmentation with breast implant, a side effect quite difficult to treat. The latest trends in the correction of capsular contracture include total capsulectomy or conversion of implant pocket. In this study, in an attempt to correct capsular contracture, the authors performed reoperation which involved capsulectomy through peri-areolar approach and dual-plane conversion. The authors hereby report the clinical results of such correction of capsular contracture and examine the efficacy. Methods: The authors selected 46 patients who were admitted to the clinic from January 2004 to January 2007 (37 months), and performed dual-plane conversion through solely peri-areolar approach. Two types of operation were done: dual-plane conversion from subglandular plane or from submuscular plane. Results: The average follow-up time after conversion to the dual-plane position was 10 months. During the follow-up period, 83.1% of patients recovered from capsular contracture and were Baker class I, and in 10.9% the condition had relapsed into Baker class II or III contracture. Conclusion: This study has proven the effectiveness of the dual-plane conversion operation for correcting established capsular contracture after previous augmentation mammaplasty. In this study, all cases of dual-plane conversion operation was performed through peri-areolar approach, which can prevent the occurrence of visible scar on inframammary fold.

• 한국통신학회논문지
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• 제27권1C호
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• pp.103-111
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• 2002

IMT-2000에서 RNC의 Main Control Processor는 호 처리를 담당하는 부분으로, 고신뢰도와 실시간성이 요구되므로 결함 허용 시스템의 연구가 중요하다. 이를 위하여 본 연구에서는 태스크 기반 이중화 방안을 제안한다. 이 방안은 Active side의 태스크들이 메시지 단위로 동작하고, 동작 후 변경된 메모리 영역의 데이터를 Standby side에 전달하는 방식을 기본으로 하며, 절체 시 recovery를 위해 메시지를 logging하는 방식이다. 제안한 방식은 dual down 및 동기화 과정의 복잡성을 제거 할 뿐만 아니라, 태스크가 동기를 제어하므로 좀 더 정확한 동기화가 가능하다. 또한 효과적으로 태스크 기반 이중화를 수행하기 위한 결함 탐지 및 처리 방안을 제시한다. 이 방안은 결함 탐지 확률을 높이고 결함에 의하여 발생한 오류 데이터가 Standby side로 전송되는 것을 원천적으로 차단하는 것에 중점을 둔다.

• 전력전자학회논문지
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• 제26권6호
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• pp.437-445
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• 2021

This paper proposes an operating frequency design method that limits the voltage applied to aload-side converter during the initial operation of a loosely coupled resonant dual-active bridge (LCR-DAB) converter and an initial operating strategy that applies it. The LCR-DAB converter uses two wireless power transfer coils instead of the high-frequency transformer of the general DAB converter. The wireless power coil has a physical distance of several tens of millimeter or more between the two coils; thus, the LCR-DAB converter is a bidirectional isolated power conversion system that can easily achieve high insulation performance. However, for the initial operation of the LCR-DAB, if the power-side converter is operated at the resonance frequency while the load-side converter is not operating, then a very high voltage due to resonance is applied to the load-side converter, thereby causing damage to the converter. Therefore, a method that can stably charge the DC link voltage of the secondary-side converter during the initial operation is needed. This paper proposes a method to initially charge the secondary-side DC link by operating the primary-side converter at a frequency with limited voltage gain rather than at a steady-state operating frequency. The validity of the proposed frequency design method and initial operating sequence is verified through simulation and experimentation of the 1 KW LCR-DAB converter.

• 문화기술의 융합
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• 제9권1호
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• pp.513-523
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• 2023

경제적 사유 및 자기계발 등을 이유로 부업을 택하는 근로자들이 점점 늘어나며 전체 경제활동인구의 1% 이상이 된 상황에서 국가 전체의 근로환경 및 개인의 삶의 질에 밀접한 영향을 줄 수 있는 부업 종사 근로자의 건강과 관련된 연구는 부족한 실정이다. 이에 제6차 근로환경조사를 원시자료로 활용하여 부업 종사자의 주관적 건강 상태에 영향을 미치는 요인들을 노동력 구조, 물리적 환경, 정서적 환경의 세 측면에서 살펴보았다. 그 결과 주업의 종사자 지위에 따라 주관적 건강 상태에 유의미한 차이가 있음을 알 수 있으며, 주업 근무 만족감을 높여주는 것과 더불어물리적으로는 장기간 지속되는 반복 업무를 하지 않고, 정서적으로는 차별 경험을 제공하지 않는 것이 근로자의 주관적 건강 상태에 있어 중요함이 통계적으로 검증되었다.

• Journal of Korean Neurosurgical Society
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• 제61권1호
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• pp.28-34
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• 2018

Objective : Duplication of the vertebral artery (VA) is a rare vascular variant. This paper describes the anatomy and embryological development of duplicated VAs and reviews the clinical significance. Methods : Computed tomography (CT) angiography was performed in 3386 patients (1880 females, 1506 males) between March 2014 and November 2015. We defined duplication of the VA as a condition in which the VA has two origins that fused at different levels of the neck. Results : Ten of the 3386 patients (0.295%) who received CT angiography had a dual origin of the VA; three on the left side, and seven on the right side. In all seven with right dual origin of the VA, both limbs of the VA origin originated from the right subclavian artery. In all three patients with left dual origin of the VA, both limbs of the VA originated from the left subclavian artery and aortic arch. In all 10 patients, the medial limb of the duplicated VA was located posteriorly and medially to the common carotid artery (CCA) and anteriorly and laterally to the vertebral transverse foramen. In two patients, the medial limb of the duplicated VA was located in close proximity to the CCA. In another two patients, the medial limb of the duplicated VA was located in close proximity to the CCA, carotid bifurcation, and proximal internal carotid artery. Conclusion : Although duplication of the VA is asymptomatic in most patients, clinicians should consider this anomaly during diagnosis and treatment.

• Journal of Power Electronics
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• 제18권3호
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• pp.662-671
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• 2018

This paper presents a new structure for a step up dc-dc converter, which has several advantageous features. Firstly, the input dc source and the clamped capacitor are connected in series to transfer energy to the load through dual voltage multiplier cells. Therefore, the proposed converter can produce a very high voltage and a high conversion efficiency. Secondly, a double voltage clamped circuit is introduced to the primary side of the coupled inductor. The energy of the leakage inductance of the coupled inductor is recycled and the inrush current problem of the clamped circuits can be shared equally by two synchronous clamped capacitors. Therefore, the voltage spike of the switch tube is solved and the current stress of the diode is reduced. Thirdly, dual voltage multiplier cells can absorb the leakage inductance energy of the secondary side of the coupled inductor to obtain a higher efficiency. Fourthly, the active switch turns on at almost zero current and the reverse-recovery problem of the diodes is alleviated due to the leakage inductance, which further improves the conversion efficiency. The operating principles and a steady-state analysis of the continuous, discontinuous and boundary conduction modes are discussed in detail. Finally, the validity of this topology is confirmed by experimental results.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1668-1671
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• 2003

A novel dual-frequency microstrip printed-dipole antenna operating at 5 GHz and 10 GHz is presented. This antenna is designed for wireless and mobile communication. The balance step coplanar strip is used to be a transmission line at the center of dipole with matching impedance at 50 ohm. Using the conductor strip align on the other side of antenna and adjust the width of step coplanar strip line to improved input impedance matching. By modification for matching impedance of dual frequency antenna are not affected to the radiation patterns. The Finite Difference Time Domain (FDTD) technique is applying to analyze the basic characteristic properties such as $S_{11}$ , input impedance , VSWR and radiation patterns. And these parameters are discussed. The analyze problem space are $51{\times}197{\times}175$ cells and cell dimension are ${\Delta}x=0.3\;mm$ and ${\Delta}y={\Delta}z=0.15\;mm$.

• 한국해안해양공학회:학술대회논문집
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• 한국해안해양공학회 2004년도 학술발표논문집 Proceedings of Coastal and Ocean Engineering in Korea
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• pp.150-159
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• 2004

In the present paper, the hydrodynamics properties of a Rahmen type flexible porous breakwater with dual fixed-pontoon system interacting with obliquely or normally incident small amplitude waves are numerically investigated. This system is composed of dual vertical porous membranes hinged a the side edges of dual fixed pontoons, and a submerged horizontal membrane that both ends are hinged at the steel frames mounted pontoons. The dual vertical membranes are extended downward and hinged at bottom steal frame fixed into seabed. The wave blocking and dissipation mechanism and its effects of permeability, Rahmen type membrane and pontoon geometry, pre-tensions on membranes, relative dimensionless wave number, and incident wave headings are thoroughly examined.

• Journal of Mechanical Science and Technology
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• 제16권12호
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• pp.1664-1672
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• 2002

Gantry mechanisms have been widely used for precision manufacturing and material handling in electronics, nuclear, and automotive industries. Dual-drive servo mechanism is a way to increase control bandwidth, in which two primary axes aligned in parallel are synchronously driven by identical servo motors. With this mechanism, a flexible coupling (compliance mechanism) is often introduced in order to avoid the damage by the servo mismatch between the primary drives located at each side of gantry. This paper describes the design guidelines of the dual-drive servo mechanism with focus on its dynamic characteristics and control ramifications. That is, the effect on the system bandwidth which is critical on the system performance, the errors and torques exerted on guide ways in case of servo mismatch, the vibration characteristics concerned with dynamic error and settling time, and the driving force required at each axis for control are thoroughly investigated.

• 한국해양공학회지
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• 제19권2호
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• pp.1-11
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• 2005

In the present paper, the hydrodynamic properties of a Rahmen type flexible porous breakwater with dual fixed pontoon system interacting with obliquely or normally incident small amplitude waves are numerically investigated. This system is composed of dual vertical porous membranes hinged at the side edges of dual fixed pontoons, and a submerged horizontal membrane that both ends are hinged at the steel frames mounted pontoons. The dual vertical membranes are extended downward and hinged at bottom steal frame fixed into seabed. The wave blocking and dissipation mechanism and its effects of permeability, Rahmen type membrane and pontoon geometry, pretensions on membranes, relative dimensionless wave number, and incident wave headings are thoroughly examined.