http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
이훈기,이정윤 대한안면통증∙구강내과학회 2016 Journal of Oral Medicine and Pain Vol.41 No.3
Purpose: The aim of this study was to develop an automated software to extract tooth and pulpal area from sectional cone-beam computed tomography (CBCT) images, which can guarantee more reproducible, objective and time-saving way to measure pulp/tooth volume ratio. Methods: The software program was developed using MATLAB (MathWorks). To determine the optimal threshold for the region of interest (ROI) extraction, user interface to adjust the threshold for extraction algorithm was added. Default threshold was determined after several trials to make the outline of extracted ROI fitting to the tooth and pulpal outlines. To test the effect of starting point location selected initially in the pulpal area on the final result, pulp/tooth volume ratio was calculated 5 times with different 5 starting points. Results: Navigation interface is composed of image loading, zoom-in, zoom-out, and move tool. ROI extraction process can be shown by check in the option box. Default threshold is adjusted for the extracted tooth area to cover whole tooth including dentin, cementum, and enamel. Of course, the result can be corrected, if necessary, by the examiner as well as by changing the threshold of density of hard tissue. Extracted tooth and pulp area are reconstructed three-dimensional (3D) and pulp/tooth volume ratio is calculated by voxel counting on reconstructed model. The difference between the pulp/tooth volume ratio results from the 5 different extraction starting points was not significant. Conclusions: In further studies based on a large-scale sample, the most proper threshold to present the most significant relationship between age and pulp/tooth volume ratio and the tooth correlated with age the most will be explored. If the software can be improved to use whole CBCT data set rather than just sectional images and to detect pulp canal in the original 3D images generated by CBCT software itself, it will be more promising in practical uses.
SiGe 에피 공정기술을 이용하여 제작된 초 접합 금속- 산화막 반도체 전계 효과 트랜지스터의 시뮬레이션 연구
이훈기,최철종,박양규,심규환 한국반도체디스플레이기술학회 2014 반도체디스플레이기술학회지 Vol.13 No.3
In this paper, we propose a super-junction MOSFET (SJ MOSFET) fabricated through a simple pillar forming process by varying the Si epilayer thickness and doping concentration of pillars using SILVACO TCAD simulation. The design of the SJ MOSFET structure is presented, and the doping concentration of pillar, breakdown voltage (VBR) and drain current are analyzed. The device performance of conventional Si planar metal-oxide semiconductor field-effect transistor(MOSFET), Si SJ MOSFET, and SiGe SJ MOSFET was investigated. The p- and n-pillars in Si SJ MOSFET suppressed the punch-through effect caused by drain bias. This lead to the higher VBR and reduced on resistance of Si SJ MOSFET. An increase in the thickness of Si epilayer and decrease in the former is most effective than the latter. The implementation of SiGe epilayer to SJ MOSFET resulted in the improvement of VBR as well as drain current in saturation region, when compared to Si SJ MOSFET. Such a superior device performance of SiGe SJ MOSFET could be associated with smaller bandgap of SiGe which facilitated the drift of carriers through lower built-in potential barrier.
시장분할기법을이용한 통행시간가치산정에관한연구 : 수도권지역의승용차운전자를중심으로
이훈기,고용석,임영태,김태희,양인석 국토연구원 2003 국토연구 Vol.39 No.-
In Korea, even though various factors have influence on the value of travel time, the guideline for road project appraisal doesn't take into account those factors and could bring distorted results. In this context, this paper aims to identify influencing factors on the value of travel time and to propose efficient and adequate standards for the value of travel time on road project appraisal. In order to identify influencing factors on the value of travel time, interview surveys were carried out on the Cheonan-Nonsan expressway, which was the second road project initiated by private financing in Korea, as well as for the metropolitan area. SP(Stated Preference) data obtained through these interview surveys enabled an estimate of discrete choice models according to market segmentation, which made it possible to identify influencing factors on the value of travel time, and proposed the value of travel time for car users. The results reveal that the values of travel time for toll road users and capital area residents are relatively higher than those of free road users and non-capital area residents. In this study, it was analyzed that income level, length of travel time and time saving/loss were key factors with impact on the value of travel time. It may be recommendable that the discriminated value of travel time reflecting travelers' behavior and location characteristics should be fully exploited for road projects.
이훈기,김태윤,김효빈,황성호 사단법인 유공압건설기계학회 2022 드라이브·컨트롤 Vol.19 No.4
Recently, various studies have been conducted to apply deep learning and AI to various fields of autonomous driving, such as recognition, sensor processing, decision-making, and control. This paper proposes a controller applicable to path following, static obstacle avoidance, and pedestrian avoidance situations by utilizing reinforcement learning in autonomous vehicles. For repetitive driving simulation, a reinforcement learning environment was constructed using virtual environments. After learning path following scenarios, we compared control performance with Pure-Pursuit controllers and Stanley controllers, which are widely used due to their good performance and simplicity. Based on the test case of the KNCAP test and assessment protocol, autonomous emergency steering scenarios and autonomous emergency braking scenarios were created and used for learning. Experimental results from zero collisions demonstrated that the reinforcement learning controller was successful in the stationary obstacle avoidance scenario and pedestrian collision scenario under a given condition.
Survival Probability Dynamics of Scaled Brownian Motion: Effect of Nonstationary Property
이훈기,송상근,김지현,성재영 대한화학회 2019 Bulletin of the Korean Chemical Society Vol.40 No.9
Scaled Brownian motion (SBM) is a popular model of nonstationary anomalous diffusion process. We here extend the SBM model to investigate the survival probability of stationary anomalous diffusion process. By making comparison between the SBM model and the stationary SBM model, we investigate the effect of stationarity on the first passage kinetics.
이훈기,한미경,장종현,Lee, H.K.,Han, M.K.,Jang, J.H. 한국전자통신연구원 2017 전자통신동향분석 Vol.32 No.5
In this paper, a video conferencing system, which has been attracting significant attention as an immersive telepresence service owing to the recent emergence of 5G networks, is described. We propose a service platform for Giga Media based video conferencing for 5G convergence services. The video conferencing service consists of a traditional structure that provides information exchange through the transmission of video and voice of remote participants using a Multipoint Control Unit (MCU), a browser-based video conferencing based on WebRTC, a multi-view point video conferencing, and holographic telepresence centered on mixed reality. The paper introduces the trends and detailed structures of various technologies used in the video conferencing system, and compares the video conferencing system technologies and video conferencing service characteristics for the integrated Giga Media platform.