• Title/Summary/Keyword: Youngchan

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Ordinal Depth Based Deductive Weakly Supervised Learning for Monocular 3D Human Pose Estimation (단안 이미지로부터 3D 사람 자세 추정을 위한 순서 깊이 기반 연역적 약지도 학습 기법)

  • Youngchan Lee;Gyubin Lee;Wonsang You
    • Proceedings of the Korea Information Processing Society Conference
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    • 2024.05a
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    • pp.826-829
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    • 2024
  • 3D 사람 자세 추정 기술은 다양한 응용 분야에서의 높은 활용성으로 인해 대량의 학습 데이터가 수집되어 딥러닝 모델 연구가 진행되어 온 반면, 동물 자세 추정의 경우 3D 동물 데이터의 부족으로 인해 관련 연구는 극히 미진하다. 본 연구는 동물 자세 추정을 위한 예비연구로서, 3D 학습 데이터가 없는 상황에서 단일 이미지로부터 3D 사람 자세를 추정하는 딥러닝 기법을 제안한다. 이를 위하여 사전 훈련된 다중 시점 학습모델을 사용하여 2D 자세 데이터로부터 가상의 다중 시점 데이터를 생성하여 훈련하는 연역적 학습 기반 교사-학생 모델을 구성하였다. 또한, 키포인트 깊이 정보 대신 2D 이미지로부터 레이블링 된 순서 깊이 정보에 기반한 손실함수를 적용하였다. 제안된 모델이 동물데이터에서 적용 가능한지 평가하기 위해 실험은 사람 데이터를 사용하여 이루어졌다. 실험 결과는 제안된 방법이 기존 단안 이미지 기반 모델보다 3D 자세 추정의 성능을 개선함을 보여준다.

Combined Filtering Model Using Voting Rule and Median Absolute Deviation for Travel Time Estimation (통행시간 추정을 위한 Voting Rule과 중위절대편차법 기반의 복합 필터링 모형)

  • Jeong, Youngje;Park, Hyun Suk;Kim, Byung Hwa;Kim, Youngchan
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.12 no.6
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    • pp.10-21
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    • 2013
  • This study suggested combined filtering model to eliminate outlier travel time data in transportation information system, and it was based on Median Absolute Deviation and Voting Rule. This model applied Median Absolute Deviation (MAD) method to follow normal distribution as first filtering process. After that, Voting rule is applied to eliminate remaining outlier travel time data after Median Absolute Deviation. In Voting Rule, travel time samples are judged as outliers according to travel-time difference between sample data and mean data. Elimination or not of outliers are determined using a majority rule. In case study of national highway No. 3, combined filtering model selectively eliminated outliers only and could improve accuracy of estimated travel time.

Design of Excitation Control System of Synchronous Generator on Board Ships (선박용 동기 발전기의 여자 제어시스템 설계)

  • Lee, Youngchan;Jung, Byung-Gun
    • Journal of Advanced Marine Engineering and Technology
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    • v.39 no.3
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    • pp.298-305
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    • 2015
  • This paper provides experimental results of an excitation control system of the synchronous generator on board ships in accordance with rules of classification society to make sure its performance. The experiment compares and reviews control results between PID control and fuzzy logic control applied to change of loads of the generator in order to make sure to satisfy the rules of classification society. Both of them are written by Labview program. In case of PID Control, this paper firstly adjusts the gains by ultimate sensitive method and the gains is more tuned by engineer's experience. And the fuzzy logic controller uses Mamdani method to make membership function for error between reference voltage and measuring voltage, differential error rate and output voltage. This paper is to make sure the experimental results of the proposed excitation control system applied to actual small synchronous generator with PID control and fuzzy logic written by using Labview program and it is proved on stability and improvement through experiments.

A study on improvement of the control performance of the automatic voltage regulator of a brushless synchronous generator (브러쉬리스 동기발전기 자동전압조정기의 제어성능 향상을 위한 연구)

  • Lee, Youngchan;Kim, Jongsu;Jung, Byung-Gun
    • Journal of Advanced Marine Engineering and Technology
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    • v.38 no.7
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    • pp.909-915
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    • 2014
  • Terminal voltage of the Automatic Voltage Regulator(AVR) of brushless synchronous generator is generally being controlled by PID Control way in shore and ship field. However, in case of changeable large load on power system, PID control method is deficiency to respond output voltage with settling time. Hence, taking into consideration this situation, it is required new control method. In this thesis, we propose Fuzzy Logic Control(FLC) which has more optimal robust control way in order to respond varying values of terminal voltage to the brushless synchronous generator through simulation of MATLAB/SIMULINK and prove Fuzzy logic control more optimal compared with PID control.

The Role of Major Donors in Health Aid to the Democratic People's Republic of Korea

  • Lee, Haewon;Ahn, Deborah Y.;Choi, Soyoung;Kim, Youngchan;Choi, Hyunju;Park, Sang Min
    • Journal of Preventive Medicine and Public Health
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    • v.46 no.3
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    • pp.118-126
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    • 2013
  • We investigated the major trends in health aid financing in the Democratic People's Republic of Korea (DPRK) by identifying the primary donor organizations and examining several data sources to track overall health aid trends. We collected gross disbursements from bilateral donor countries and international organizations toward the DPRK according to specific health sectors by using the Organization for Economic Cooperation and Development creditor reporting system database and the United Nations Office for the Coordination of Humanitarian Affairs financial tracking service database. We analyzed sources of health aid to the DPRK from the Republic of Korea (ROK) using the official records from the ROK's Ministry of Unification. We identified the ROK, United Nations Children's Fund (UNICEF), World Health Organization (WHO), United Nations Population Fund (UNFPA), and The Global Fund to Fight AIDS, Tuberculosis and Malaria (GFATM) as the major donor entities not only according to their level of health aid expenditures but also their growing roles within the health sector of the DPRK. We found that health aid from the ROK is comprised of funding from the Inter-Korean Cooperation Fund, private organizations, local governments, and South Korean branches of international organizations such as WHO and UNICEF. We also distinguished medical equipment aid from developmental aid to show that the majority of health aid from the ROK was developmental aid. This study highlights the valuable role of the ROK in the flow of health aid to the DPRK, especially in light of the DPRK's precarious international status. Although global health aid from many international organizations has decreased, organizations such as GFATM and UNFPA continue to maintain their focus on reproductive health and infectious diseases.

A Development of the Traffic Signal Progression Model for Tram and Vehicles (간선도로 트램 전용차로에서 트램과 일반차량을 위한 신호최적화 모형 개발)

  • Lee, In-Kyu;Kim, Youngchan
    • Journal of Korean Society of Transportation
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    • v.32 no.3
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    • pp.280-292
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    • 2014
  • A tram has been the focus of a new public transportation that can solve a traffic jam, decreasing of public transit usage and environmental problem in recent years. This study aims to develop a signal optimization model for considering the traffic signal progression of tram and vehicles, when they are operated simultaneously in the same signalized intersections. This research developed the KS-SIGNAL-Tram model to obtain a minimum tram bandwidth and to minimize a vehicle's delay to perform a tram passive signal priority, it is based on the KS-SIGNAL model and is added to the properties of a tram and it's system. We conducted a micro simulation test to evaluate the KS-SIGNAL-Tram model, it showed that the developed optimization model is effective to prevent a tram's stop on intersection, to reduce a tram's travel time and vehicle's delay.

Low-Temperature Processed Thin Film Barrier Films for Applications in Organic Electronics (유기전자소자 적용을 위한 저온 공정용 배리어 박막 연구)

  • Kim, Junmo;An, Myungchan;Jang, Youngchan;Bae, Hyeong Woo;Lee, Wonho;Lee, Donggu
    • Journal of Sensor Science and Technology
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    • v.28 no.6
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    • pp.402-406
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    • 2019
  • Recently, semiconducting organic materials have been spotlighted as next-generation electronic materials based on their tunable electrical and optical properties, low-cost process, and flexibility. However, typical organic semiconductor materials are vulnerable to moisture and oxygen. Therefore, an encapsulation layer is essential for application of electronic devices. In this study, SiNx thin films deposited at process temperatures below 150 ℃ by plasma-enhanced chemical vapor deposition (PECVD) were characterized for application as an encapsulation layer on organic devices. A single structured SiNx thin film was optimized as an organic light-emitting diode (OLED) encapsulation layer at process temperature of 80 ℃. The optimized SiNx film exhibited excellent water vapor transmission rate (WVTR) of less than 5 × 10-5 g/㎡·day and transmittance of over 87.3% on the visible region with thickness of 1 ㎛. Application of the SiNx thin film on the top-emitting OLED showed that the PECVD process did not degrade the electrical properties of the device, and the OLED with SiNx exhibited improved operating lifetime

Development of Traffic Speed Prediction Model Reflecting Spatio-temporal Impact based on Deep Neural Network (시공간적 영향력을 반영한 딥러닝 기반의 통행속도 예측 모형 개발)

  • Kim, Youngchan;Kim, Junwon;Han, Yohee;Kim, Jongjun;Hwang, Jewoong
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.19 no.1
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    • pp.1-16
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    • 2020
  • With the advent of the fourth industrial revolution era, there has been a growing interest in deep learning using big data, and studies using deep learning have been actively conducted in various fields. In the transportation sector, there are many advantages to using deep learning in research as much as using deep traffic big data. In this study, a short -term travel speed prediction model using LSTM, a deep learning technique, was constructed to predict the travel speed. The LSTM model suitable for time series prediction was selected considering that the travel speed data, which is used for prediction, is time series data. In order to predict the travel speed more precisely, we constructed a model that reflects both temporal and spatial effects. The model is a short-term prediction model that predicts after one hour. For the analysis data, the 5minute travel speed collected from the Seoul Transportation Information Center was used, and the analysis section was selected as a part of Gangnam where traffic was congested.

Thermal Transfer Pixel Patterning by Using an Infrared Lamp Source for Organic LED Display (유기 발광 소자 디스플레이를 위한 적외선 램프 소스를 활용한 열 전사 픽셀 패터닝)

  • Bae, Hyeong Woo;Jang, Youngchan;An, Myungchan;Park, Gyeongtae;Lee, Donggu
    • Journal of Sensor Science and Technology
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    • v.29 no.1
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    • pp.27-32
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    • 2020
  • This study proposes a pixel-patterning method for organic light-emitting diodes (OLEDs) based on thermal transfer. An infrared lamp was introduced as a heat source, and glass type donor element, which absorbs infrared and generates heat and then transfers the organic layer to the substrate, was designed to selectively sublimate the organic material. A 200 nm-thick layer of molybdenum (Mo) was used as the lightto-heat conversion (LTHC) layer, and a 300 nm-thick layer of patterned silicon dioxide (SiO2), featuring a low heat-transfer coefficient, was formed on top of the LTHC layer to selectively block heat transfer. To prevent the thermal oxidation and diffusion of the LTHC material, a 100 nm-thick layer of silicon nitride (SiNx) was coated on the material. The fabricated donor glass exhibited appropriate temperature-increment property until 249 ℃, which is enough to evaporate the organic materials. The alpha-step thickness profiler and X-ray reflection (XRR) analysis revealed that the thickness of the transferred film decreased with increase in film density. In the patterning test, we achieved a 100 ㎛-long line and dot pattern with a high transfer accuracy and a mean deviation of ± 4.49 ㎛. By using the thermal-transfer process, we also fabricated a red phosphorescent device to confirm that the emissive layer was transferred well without the separation of the host and the dopant owing to a difference in their evaporation temperatures. Consequently, its efficiency suffered a minor decline owing to the oxidation of the material caused by the poor vacuum pressure of the process chamber; however, it exhibited an identical color property.

Integrated Traffic Management Strategy on Expressways Using Mainline Metering and Ramp Metering (본선미터링과 램프미터링을 이용한 고속도로 통합교통관리 전략)

  • Jeong, Youngje;Kim, Youngchan;Lee, Seungjun
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.12 no.2
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    • pp.1-11
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    • 2013
  • This research proposed integrated expressway traffic management strategy using ramp metering and toll mainline metering. This research suggested a traffic signal optimization model for integrated operation of ramp and mainline metering based on Demand-Capacity Model that is used to optimize allowable input volume for ramp metering in FREQ model. The objective function of this model is sectional throughput volume maximization, and this model can calculate optimal signal timings for mainline metering and ramp metering. This study conducted an effectiveness analysis of integrated metering strategy using PARAMICS and its API. It targeted Seoul's Outer Ring Expressway between Gimpo and Siheung toll gate. As a simulation result, integrated operation of mainline and ramp metering provided more smooth traffic flow, and throughput volume of mainline increased to 14% in congested section. In addition, a queue of 400 meter was formed at metering point of toll gate. This research checked that integrated traffic management strategy facilitates more efficient traffic operation of mainline and ramp from diffused traffic congestion.