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Fabrication of three-dimensional scan-to-print ear model for microtia reconstruction
Jeon, Byoungjun,Lee, Chiwon,Kim, Myungjoon,Choi, Tae Hyun,Kim, Sungwan,Kim, Sukwha Elsevier 2016 Journal of Surgical Research Vol.206 No.2
<P><B>Abstract</B></P> <P><B>Background</B></P> <P>Microtia is a congenital deformity of the external ear that occurs in 1 of every 5000 births. Microtia reconstruction using traditional two-dimensional templates does not provide highly detailed ear shapes. Here, we describe the feasibility of using a three-dimensional (3D) ear model as a reference.</P> <P><B>Materials and methods</B></P> <P>Seven children aged from 11 to 16 (6 grade III and 1 grade II microtia) were recruited from Seoul National University Children's Hospital, Korea. We generated 3D–computer-aided design models of each patient's ear by performing 3D laser scanning for a mirror-transformed cast of their normal ear. The 3D-printed ear model was used in microtia reconstruction surgery following the Nagata technique, and its shape was compared with the casted ear model.</P> <P><B>Results</B></P> <P>One patient experienced irritation caused by accidently pouring resin into the external auditory meatus, and another had minor skin necrosis; both complications were successfully treated. The average percentage differences of the superior, inferior, anterior, posterior, and lateral views between the casted and 3D-printed ear models were 1.17%, 1.48%, 1.64%, 1.80%, and 5.44%, respectively (average: 2.31%), where the difference between the casted ear models and traditional two-dimensional templates were 16.03% in average.</P> <P><B>Conclusions</B></P> <P>Our results show that simple microtia reconstruction can be performed using 3D ear models. The 3D-printed ear models of each patient were consistent and accurately represented the thickness, depth, and height of the normal ear. The availability of the 3D-printed ear model in the operating room reduced the amount of unnecessary work during surgery.</P>
지진격리된 원자력발전소 연결배관의 실제 손상 기반 지진취약도 분석
전법규 ( Jeon Bubgyu ),김성완 ( Kim Sungwan ),윤다운 ( Yun Dawoon ),임승현 ( Eem Seunghyun ),함대기 ( Hahm Daegi ) 한국복합신소재구조학회 2021 복합신소재구조학회논문집 Vol.12 No.3
원자력 발전소에 지진격리장치를 설치하여 내진성능을 향상시킬 수 있다. 그러나 지진격리장치의 적용으로 지반과 구조물 사이에서 큰 상대 변위가 발생하게 된다. 따라서 지진격리된 구조물과 일반 구조물을 연결하는 연결배관시스템의 경우 지진리스크가 증가할 수 있다. 따라서 이러한 배관시스템의 지진취약도를 분석할 필요가 있다. 본 연구에서는 지진취약도 분석을 위해 지진격리된 APR1400 원자력발전소와 주증기관을 대상으로 지진취약도를 분석하였다. 주증기관은 지진격리된 nuclear island의 보조 건물과 터빈 건물을 연결하는 인터페이스 배관이다. 지진취약도 분석을 위한 파괴모드는 누출관통균열로 정의하였다. 누출은 실험결과와 수치해석을 통해 손상지수로 정량화하여 취약도 분석을 위한 파괴기준으로 사용하였다. 파괴기준의 변동에 의한 취약도 곡선의 변동성을 확인하기 위하여 손상지수의 최솟값, 최댓값, 평균값 및 중앙값을 파괴기준으로 하여 지진취약도 곡선을 작성하였다. A seismic isolation system installed in a nuclear power plant (NPP) can withstand a load caused by an earthquake. However, a larger relative displacement may occur in the system compared with its absence. Therefore, the seismic risk in an interface piping system that connects base-isolated and general structures can increase. Hence, seismic-fragility analysis of these piping systems is necessary. In this study, a seismic-fragility analysis was performed on base-isolated APR1400 NPPs and their main steam line. The main steam line is an interface pipe that connects the base-isolated auxiliary and turbine buildings. The failure mode of the seismic-fragility analysis was defined as a leak-through crack. The leakage point was quantified as a damage index through the experimental and numerical analysis results and was employed as a failure criterion in the seismic-fragility analysis. The seismic-fragility curves were assigned representative values as damage indexes, namely, average, median, maximum, and minimum, at the leak point by considering the uncertainty of the failure criterion.
Seismic response evaluation of 154 kV transformer porcelain bushing by shaking table tests
Nakhyun Chun,Bubgyu Jeon,Sungwan Kim,Sungjin Chang,Suwon Son 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.84 No.2
The use of electricity and communication between electronic devices is increasing daily, which makes the stability of electrical power supply vital. Since the 1990s, large earthquakes have occurred frequently causing considerable direct damage to electrical power facilities as well as secondary damage, such as difficulty in restoring functions due to the interruption of electric power supply. Therefore, it is very important to establish measures to protect electrical power facilities, such as transformers and switchboards, from earthquakes. In this study, a 154 kV transformer whose service life had expired was installed on the base fabricated by simulating the field conditions and conducting the shaking table tests. The dynamic characteristics and seismic behavior of the 154 kV transformer were analyzed through the resonance frequency search test and seismic simulation test that considers the front, rear, left, and right directions. Since the purpose of this study is to analyze the acceleration amplification in the bushing due to the acceleration amplification, the experimental results were analyzed focusing on the acceleration response and the converted acceleration amplification ratio rather than the failure due to the displacement response of the transformer. The seismic force amplification at the transformer bushing was evaluated by simulating the characteristics of electrical power facilities in South Korea, and compared with the IEC TS 61463 acceleration amplification factor. Finally, the amplification factor at zero period acceleration (ZPA) modified for each return period was summarized. The results of this study can be used as data to define the amplification factor at ZPA of the transformer bushing, simulating the characteristics of electrical power facilities in Korea.
Yunhee Lee,채영문,Sungwan Jeon 대한의료정보학회 2010 Healthcare Informatics Research Vol.16 No.4
Objectives: The purpose of this study was to develop clinical decision support systems (CDSS) that are integrated with hospital information systems for the differential diagnosis of idiopathic pulmonary fibrosis (IPF). Methods: The integrated CDSS were validated and evaluated by physicians. Knowledge modeling for diagnosing IPF was performed by knowledge working groups, composed of radiologists and respiratory specialists. In order to develop the model for CDSS diagnosis, the clinical cases were collected from 290 cases from Seoul National University Hospital and Sevrance Hospital of Yonsei University. For the evaluation of integrated CDSS, interviews were conducted with respiratory specialists and radiologist 2 weeks after applying CDSSs in clinical settings. The CDSS was integrated with the computer vision system (CVS) and diffuse parenchymal lung diseases (DPLD), CDSS developed in our previous project. Results: Eighteen cases diagnosed as IPF were applied to the collection of diagnostic knowledge and the refined knowledge, the former diagnosed 1 case (6%) and the latter diagnosed 14cases (78%). Therefore, the refined knowledge performed better than collected knowledge. The validation results of integrated CDSSs showed that 81 cases (74.3%) were diagnosed correctly. Conclusions: There were 109 cases of IPF diagnosed and initiated on treatment. The significance of this study is in developing integrated CDSS with PACS by acquiring and redefining the knowledge needed for IPF diagnosis. In addition, it is significant for the integration of CDSS to verification and clinical evaluation.
Yoo, Chanuk,Yang, Yeongae,Baik, Sungwan,Kim, Jaehyung,Jeon, Gyerok Korea Multimedia Society 2017 멀티미디어학회논문지 Vol.20 No.2
For many stroke patients undergoing rehabilitation therapy, there is a need for indicator for evaluating the body function in paretic and non-paretic regions of stroke patients quantitatively. In this paper, the function of muscles and cells in paretic and non-paretic regions of severe and mild hemiplegic stroke patients was evaluated using multi-channel bioelectrical impedance spectroscopy. The paretic and non-paretic regions of severe and mild stroke patients were quantitatively assessed by using bioelectrical impedance parameters such as prediction marker (PM), phase angle (${\theta}$), characteristic frequency ($f_c$), and bioelectrical impedance vector analysis (BIVA). The mean values of impedance vector were significantly discriminated in all comparisons (severe-paretic, severe-non-paretic, mild-paretic, and mild-non-paretic). The bioelectrical impedance parameters were proved to be a very valuable tool for quantitatively evaluating the paretic and non-paretic regions of hemiplegic stroke patients.
A Study on the VR Goggle-based Vision System for Robotic Surgery
Young Gyun Kim,Gyeongbin Mun,Byoungjun Jeon,Jong Hyeon Lee,Dan Yoon,Byeong Soo Kim,Myungjoon Kim,Seong-Ho Kong,Kyu Eun Lee,Chang Wook Jeong,Minwoo Cho,Sungwan Kim 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.9
Robot-assisted surgery (RAS) using the da Vinci surgical system (dVSS) has been widely performed owing to its high-definition stereoscopic visualization and improved maneuverability, which has been developed from minimally invasive surgery. However, there was motivation to resolve the chronic fatigue suffered by surgeons because of stereo viewer, the vision system of the dVSS. Reflecting the clinical opinions, a virtual reality (VR) goggle was proposed to enhance the convenience by replacing the stereo viewer, and its applicability was investigated. Based on the da Vinci research kit, validation of the VR goggle was performed by analyzing the condition of its use and implementing the performance assessment. In addition, user evaluations, such as performance analysis, questionnaire surveys, and ergonomic analysis, were conducted to determine the difference in the performance and satisfaction between the stereo viewer and VR goggle. Following the IRB approval, a retrospective analysis of the results was performed. Based on the comparison between the vision systems, the VR goggle was evaluated positively by the surgeons and novices. Satisfaction with the ergonomic properties of the VR goggle averaged 3.9 on a five-point Likert scale, and there was no significant difference in the performance when using the VR goggle and stereo viewer in both groups. Adopting the VR goggle, the volume of the vision system could be decreased by 87.6%. Considering that the VR goggle was better than the stereo viewer in terms of satisfaction and ergonomic analysis with analogous performance, it has the main contribution that the VR goggle can be a promising candidate. as a new vision baseline to research the enhancements of the RAS platform in further studies.