Investigation of GaAs over AlGaAs and InGaP Selective Dry Etching in Planar Inductively Coupled Plasmas with BCl₃ / SF6 based Chemistries

유승열,장수욱,류현우,박민영,최충기,임완태,이제원,조관식,전민현,송한정 한국진공학회 2005 한국진공학회 학술발표회초록집 Vol.- No.-

알레르기성 비염 환자의 피부반응검사 및 RAST 검사의 비교

유승열,홍승인,김성완,이성만,김광일,유성근 대한이비인후과학회 1991 대한이비인후과학회지 두경부외과학 Vol.34 No.6

평판형 유도결합 BCl₃/SF₆플라즈마를 이용한 GaAs/AlGaAs 선택적 식각에 관한 연구

유승열,임완태,백인규,이제원,조관식,전민현,송한정 한국표면공학회 2004 한국표면공학회 학술발표회 초록집 Vol.2004 No.-

무작위 생성 심층신경망 기반 유기발광다이오드 흑점 성장가속 전산모사를 통한 소자 변수 추출

유승열,박일후,김규태,You, Seung Yeol,Park, Il-Hoo,Kim, Gyu-Tae 한국반도체디스플레이기술학회 2021 반도체디스플레이기술학회지 Vol.20 No.3

Numbers of studies related to optimization of design of organic light emitting diodes(OLED) through machine learning are increasing. We propose the generative method of the image to assess the performance of the device combining with machine learning technique. Principle parameter regarding dark spot growth mechanism of the OLED can be the key factor to determine the long-time performance. Captured images from actual device and randomly generated images at specific time and initial pinhole state are fed into the deep neural network system. The simulation reinforced by the machine learning technique can predict the device parameters accurately and faster. Similarly, the inverse design using multiple layer perceptron(MLP) system can infer the initial degradation factors at manufacturing with given device parameter to feedback the design of manufacturing process.

계수추정법을 이용한 PEMFC에서의 실시간 상태 추정 방법 개발

유승열,최동희 한국수소및신에너지학회 2016 한국수소 및 신에너지학회논문집 Vol.27 No.1

The development need of new renewable energy is more and more important to resolve exhaustion of chemical fuels and environmental pollution. Polymer electrolyte membrane fuel cell has been widely studied to the extent that it can be used commercially. But there are many problems to be solved. One of them is to enhance the stability of fuel cell stacks. This paper proposes a new fault diagnosis method using Least Square Method (LSM) which is one of parameter estimation methods. The proposed method extracts equivalent circuit parameters from on-line measurements. Parameters of the circuit are estimated according to normal and abnormal states using simulation. The variation of parameters estimated in each states enables the estimation of state in fuel cells. Thus the LSM presented can be a suitable on-line parameter estimation method in PEMFC.

순환신경망 기법을 이용한 스파 플랫폼의 시계열데이터 필터링에 관한 연구

유승열,이재철,이종현,황호진,이순섭 한국마린엔지니어링학회 2019 한국마린엔지니어링학회지 Vol.43 No.1

There is growing interest in the numerous techniques focused on analyzing vast quantities of measurement data in real time for the development of smart ships along with the development of asset integrity management systems for offshore platforms. To analyze the measurement data in real time, data filtering is used to eliminate the noise in the data and then extract the necessary information to perform a comprehensive data analysis. In the traditional shipbuilding and offshore industry, spectrum-based filtering methods are used because the corresponding data is saved for a certain period and subsequently analyzed. These methods are not suited to the present situation in which real-time data is required to be analyzed. Therefore, a new method for data filtering is required. The objective of this study is to filter data in real time using a recurrent neural network algorithm, which is a deep learning model used for learning time series data. In order to filter the measured mooring tension value of the spa platform in real time, a filtering model comprising a recurrent neural network algorithm was designed, and the results of the data filtering process were verified to confirm the possibility of real- time filtering. 스마트 선박 (Smart ship)의 개발과 해양 플랫폼의 예지보전 시스템 및 자산 관리 시스템 개발을 위해 방대한 양의계측 데이터를 실시간으로 분석할 수 있는 기술에 대한 관심이 높아지고 있다. 이러한 계측 데이터를 실시간으로 분석하기 위해서는 계측 데이터의 노이즈를 제거하고 필요한 정보를 추출하여 분석에 용이한 형태로 데이터를 가공하는 과정인 데이터 필터링이 반드시 선행되어야 한다. 기존의 조선 해양 산업에서는 일정기간 이상 데이터를 저장한 후 이에대한 분석을 실시하여 스펙트럼 기반의 필터링 기법을 많이 이용하였다. 이러한 방법은 실시간 데이터를 분석해야 하는현 상황에는 적합하지 않아 실시간 데이터를 필터링하기 위한 새로운 기법이 필요한 실정이다. 본 논문에서는 시계열데이터를 학습하기 위한 딥 러닝 모델인 순환신경망 알고리즘을 이용하여 실시간으로 전송되는 데이터를 필터링하고자하였다. 실시간으로 계측되는 스파 플랫폼의 계류 장력 값을 필터링하기 위해 순환신경망 알고리즘을 이용한 필터링 모델을 설계하고 그 결과값을 확인하여 실시간 필터링 가능 여부를 확인하였다. 최종적으로 실시간으로 전송되는 데이터를 필터링 하기 위해 순환신경망 알고리즘을 사용하는 것이 적합하다는 것을 확인하였다.

시뮬레이션에 의한 컨테이너 물류시스템의 분석에 관하여(BCTOC를 중심으로)

유승열,여기태,이철영 한국항해항만학회 1997 한국항해학회지 Vol.21 No.1

Because of the sharp increase of its export and import container cargo volumes contrast to the lack of related Container Terminal facility, equipment and inefficient procedure, there is now heavy container cargo congestions in Pusan Container Terminal. As a result of such a situation, many container ships avoid their calls into Pusan port. This is a major cause that in tum kads to weakening intemational competitiveness of the Korean industry. This study, therefore, aims are to make a quantitative analysis of Container Terminal System through the computer simulation, especially focusing on its 4 sub-system of a handling system, 'it is checked whether the current operation is being performed effectively through the computer simulation. The overall findings are as folIows; Firstly, average tonnage of the ships visiting the BCTOC was 32,360 G/T in from January '96, to may '96. The average arrival interval and service time of container ships at BCTOC are 5.63 hours and 18.67 hours respectively. Ship's arrival and service pattern at BCTOC was exponential distribution with 95% confidence and Erlang-4 distribution with 99% confidence. Secondly, average waiting time and number of ships was 9.9 hours, 235 ships(38%) among 620 ships. Number of stevedoring container per ship was average 747.7 TED, standard deviation 379.1 TEU and normal distribution with 99% confidence. Thirdly, from the fact that the average storage days of containers at BCTOC are 2.75 days (3.0 days when import, 2.5 days when export). it is founds that most containers were transfered to the off-dock storage areas with the free periods(5 days when import, 4 days when export), the reason for which is considered to be the insufficient storage area at BCTOC. Fourthly, in the case of gate in-out at BCTOC, occupied containers and emptied containers are 89% and 11% respectively in the gate-in, 75% and 25% seperately in the gate-out. Finally, from the quantitative analysis results for container terminal at BCTOC, ship's average wating time of ships was found to be 20.77 hours and berth occupancy rate(${\rho}$) was 0.83. 5~6 berths were required in order that the berth occupancy rate(${\rho}$) may be maintained up to 60% degree.

솔레노이드의 고속 동작을 위한 모델링 및 제어

유승열,신동훈 한국반도체디스플레이기술학회 2011 반도체디스플레이기술학회지 Vol.10 No.4

Electronics in modern life have become more miniaturized and precise and new technology of electronic components has made these trends possible. The explosive demand of electronic components needs more high-speed and accurate performance of manufacturing processes. For high-speed actuation, solenoids, voice coil motors and piezo motors have been used. A solenoid actuator characterized by low price, available small size, and convenience is one of the main components of production equipments requiring compact and high-speed actuators. Since these actuators show millisecond order responsiveness, the improvement of 1~2msec is very important in industrial applications. In this paper, the mathematical model of the solenoid is formulated and simulated using SIMULINK^®. To verify the model, the responses for step input with open-loop control is obtained and compared with the simulation result. In order to improve the responsiveness, Hold voltage method is introduced and optimal value between spring constant and hold voltage is suggested.

해양플랜트 장비 성능 모니터링 시스템을 위한 데이터베이스 설계

유승열,서주완,이재철,황세윤,황호진,이순섭,Yoo, Seung-Yeol,Seo, Ju-Wan,Lee, Jae-Chul,Hwang, Se-Yun,Hwang, Ho-Jin,Lee, Soon-Sup 해양환경안전학회 2020 海洋環境安全學會誌 Vol.26 No.5

안전한 해양플랜트 운용을 위해 장비 성능평가를 실시하고 그 결과를 모니터링 할 수 있는 시스템이 필요하다. 현재는 육상으로부터 멀리 떨어진 해양플랜트의 특성상 장비 성능평가를 위해 정기적으로 계측 데이터를 저장매체에 저장한 후 육상으로 운반해야한다. 이로인해 성능평가 주기가 길어지고, 다음 성능평가가 시행되기 전까지의 장비의 성능 저하 정도를 알 수 없어 장비의 고장을 방지하기 어렵다. 따라서 육상이 아닌 해양플랜트 내에 온보드(on-board) 형태의 장비 성능 모니터링 시스템을 구축할 필요가 있다. 본 논문에서는 해양플랜트 내에서 장비 성능을 평가하고 그 결과를 가시화하는 장비 성능 모니터링 시스템을 개발하기 위한 초기 단계로, 장비 성능 모니터링 시스템의 데이터베이스를 설계 및 구축하고자 한다. 이를 위해 주요 장비의 태그 데이터를 선정하여 분석을 진행하였다. 최종적으로 장비 상태를 실시간으로 계측한 데이터를 해양플랜트 내에서 저장 및 관리하기 위해 온보드 형태의 장비 성능 모니터링 시스템을 위한 데이터베이스를 설계 및 구축 하였다. To ensure the safe operation of offshore plants, a system is needed for evaluating the equipment performance and for monitoring the results. Currently, owing to the operating environments of of shore plants situated far from the land, measurement data must be periodically stored in storage devices and carried on the land for evaluating the equipment performance. Consequently, it is difficult to prevent equipment failure because the performance evaluation cycle is long. Furthermore, until the next performance evaluation is conducted, it is difficult to determine the equipment's degree of performance degradation. Hence, it is necessary to install an onboard equipment performance monitoring system within the offshore plant. In this study, to evaluate and visualize the results of equipment performance within an offshore plant, a database was designed as the initial step towards the development of an equipment performance monitoring system. The tag data of major equipment were selected and analyzed. Furthermore, in order to store and manage the data measured in real time within the offshore plant, a database was developed for the onboard equipment performance monitoring system.

멀티캐스트 버시티 트래픽하에서 입출력단에 버퍼를 갖는 ATM 교환기의 성능 분석 ( Performance of input and output Queuing ATM Switch Under Multicast Bursty Traffic )

유승열,김석희,최병석,박현민,박재현 대한전자공학회 1997 대한전자공학회 학술대회 Vol.1997 No.1