• Journal of Yeungnam Medical Science
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• 제39권1호
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• pp.53-57
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• 2022

Hepatic hemangiomas infrequently exhibit atypical imaging features, which may cause diagnostic confusion with hepatic malignancies and lead to unnecessary surgery. We report a rare case of multilocular cystic hemangioma of the liver mimicking a mucinous cystic neoplasm of the liver in a 48-year-old female, focusing on computed tomography and magnetic resonance imaging features and their differential diagnosis.

• Korean Circulation Journal
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• 제53권1호
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• pp.52-54
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• 2023

• 한국의학물리학회지:의학물리
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• 제21권1호
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• pp.29-34
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• 2010

본 연구에서는 치료용 양성자선 계측을 위한 광섬유 방사선량계 개발을 목적으로 최적화 과정의 기초연구를 통하여 광섬유 방사선량계를 제작하였다. 양성자선 계측의 최적화를 위해 유기섬광체의 종류에 따른 섬광량 및 브래그 피크의 피크/플래투를 측정하여 가장 효율이 뛰어난 섬광체를 선별하였고, 유기섬광체의 직경에 따라 물 팬텀의 각 깊이에서 손실되는 양성자선의 에너지에 대해 유기섬광체에서 발생되는 섬광량을 측정하여 유기섬광체의 직경에 따른 선형성을 도시하고 최적의 섬광체 직경을 선택하였다. 또한 양성자선의 조사각도에 대해 유기섬광체의 길이에 따른 섬광량 및 섬광량의 표준편차를 측정하여 입사각 의존도를 판별하고 최적의 섬광체 길이를 결정하였다. 최적화 과정을 통하여 제작된 센서 성능평가의 일환으로 양성자 가속기의 선량율 및 모니터 유닛에 따른 광섬유 방사선량계의 섬광량을 측정하였다.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 춘계학술대회
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• pp.387-390
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• 1997

Electrogastrography(EGG), the cutaneous recording of the myoelectrical activity of the stomach using surface electrodes, is attractive due to its non-invasiveness. We propose feasible methods to detect tile gastric contraction by vector analysis of the surface EGG signals obtained from three paired electrodes. The amplitude and direction of the calculated EGG vector were analyzed and compared with the gastric contraction signals such as the strain gauge signal from the gastric serosa in dog. From the vector analysis of the EGG signal, we found a typical change of the amplitude and direction of the EGG vector, which can indicate occurrences of the gastric contraction.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 춘계학술대회
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• pp.342-344
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• 1997

Owing to technical advances in very large-scale integrated circuits (VLSI), high-speed digital signal processing (DSP) chips become fast enough to allow for real-time implementation of hearing aid algorithms in units small enough to be wearable. In this paper, we present a digital hearing aid processor (DHAP) chip built around a general-purpose 16-bit DSP core. The designed DHAP performs a nonlinear loudness correction of 8 octave frequency bands based on audiometric measurements. By employing a programmable DSP, the DHAP provides all the flexibility needed to implement audiological algorithms. In addition, the has a low power feature and $5.410\times5.720mm^2$ dimensions that fit for wearable devices.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 추계학술대회
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• pp.142-145
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• 1997

This paper presents the development of depth extraction algorithm or the 3D Endoscopic Data using a stereo matching method and depth calculation. The purpose of other's algorithms is to reconstruct 3D object surface and make depth map, but a one of this paper is to measure exact depth information on the base of [cm] from camera to object. For this, we carried out camera calibration.

• Journal of Chest Surgery
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• 제51권5호
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• pp.356-359
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• 2018

We report a case of successful repair of truncus arteriosus (TA) associated with complete atrioventricular septal defect (c-AVSD) using a staged approach. TA associated with c-AVSD is a very rare congenital cardiac anomaly. No report of successful staged repair in South Korea has yet been published. We performed bilateral pulmonary artery banding when the patient was 33 days old, and total correction using an extracardiac conduit was performed at the age of 18 months. The patient recovered uneventfully and is doing well.

• 대한의용생체공학회:의공학회지
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• 제27권6호
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• pp.402-408
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• 2006

The choice of suitable hip implant is one of important factors in the total hip arthroplasty (THA). In clinical view point, an improper adaptation of hip implant might induce abnormal stress distribution to the bone, which can shorten the lifespan of replaced hip implant. Currently, interest in the custom-designed hip implants has increased as studies reveal the significance of geometric shape of patient's femur in modeling and designing the implants. In this study, we have developed custom-designed hip implant models with various sizes, and analyzed the stress distribution in the bone and bone cement using the Finite Element Method. It was found that minimizing the gap between implant stem and femoral cavity is crucial to minimize the stress concentration in the bone.

• BMB Reports
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• 제44권7호
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• pp.478-483
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• 2011

Hairless (HR), a transcriptional cofactor, is highly expressed in the skin and brain. To characterize the effects of HR expression in the skin, we examined its capacity for transcriptional regulation of its target genes in mouse skin and keratinocytes. We found that Foxe1 mRNA expression was suppressed in HR-overexpressing skin, as well as in HR-expressing keratinocytes. In turn, Msx1 expression was downregulated contingent on Foxe1 downregulation in skin and keratinocytes. We also found that expression of Sfrp1 was also correlated with that of Foxe1. Further investigation of the mechanisms involved in the transcriptional regulation of these genes will facilitate our understanding of the relationship among genes involved in hair follicle morphogenesis and cycling.

• 대한의용생체공학회:의공학회지
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• 제26권1호
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• pp.17-22
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• 2005

Small animal PET using a dual layer phoswich detector has been developed to obtain high and uniform spatial resolution. In this study, a simple analytic model to optimize the lengths of a dual layer phoswich detector was derived and validated by Monte Carlo simulation. For a small animal PET scanner with a 10㎝ ring diameter, the optimal length of the phoswich detector consisting of various crystal materials, such as LSO and LuYAP, were calculated analytically and validated using GATE. The detector module consisted of 8×8 arrays of crystals, with each phoswich detector element having a 2㎜×2㎜ sensitive area. The total crystal length was fixed to 20㎜. The optimal lengths of the phoswich detector layers, as functions of the crystal materials and order, conveniently derived by the analytic equation, showed good agreement with those estimated by the time consuming simulation. The simple analytical model can be used for the fast and accurate design of an optimal phoswich detector for small animal PET to achieve high spatial resolution and uniformity.