• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.4-6
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• 2003

We have developed the active matrix OLED displays with a high efficiency red emission material which uses an emitting assist (EA) dopant system. The EA dopant (rubrene) did not itself emit but assisted the energy transfer from the host ($Alq_s$) to the red emitting dopant(DCM2). A stable red emission (chromaticity coordinates: x=0.64, y=0.36) was obtained in this cell within the luminance range of 100 - 4000 $cd/m^2$ By using EA dopant system, we can realize the reduction of the power consumption of the OLED display..

• Laser Solutions
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• v.2 no.1
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• pp.30-37
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• 1999

Laser-welded Tailored Blank is the hottest thing in many automobile companies. But they demand on weld quality, reproducibility, and formability. So it is the great problem of automation of laser welding process. Therefore, it is requested to construct on-line process monitoring system on high accuracy. The light which is emitted from plasma and spatter in laser welding was detected by photo-diodes. It was found that the light intensity depends on welding speed. laser power, and flow rate of assist gas. The relationship between the plasma and spatter and the weld quality can be used for on-line laser weld monitoring systems.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.8
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• pp.831-840
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• 1992

This paper presents an efficient short-term generation scheduling method using a rule-based expert/consulting system approach to assist electric energy system operators and planners. The expert system approach is applied to improve the Dynamic Programming(DP) based generation scheduling algorithm. In the selection procedure of the feasible combinations of generating units at each stage, automatic consulting on the manipulation of several constraints such as the minimum up time, the minimum down time and the maximum running time constraints of generating units will be performed by the expert/consulting system. In order to maximize the solution feasibility, the aforementioned constraints are controlled by a rule-based expert system, that is, instead of imposing penalty cost to those constraint violated combinations, which sometimes may become the very reason of no existing solution, several constraints will be manipulated within their flexibilities using the rules and facts that are established by domain experts. In this paper, for the purpose of implementing the consulting of several constraints during the dynamic process of generation scheduling, an expert system named STGSCS is developed. As a building tool of the expert system, C Language Integrated Production System(CLIPS) is used. The effectiveness of the proposed algorithm has been demonstrated by applying it to a model electric energy system.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.728-731
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• 2005

A light guide panel (LGP) is an element of the LCD back light unit, which is used for display devices. In this study, a laser marking process is applied to the fabrication of light guide panels as the new fabrication process. In order to obtain a light guide panel which has high luminance and uniformity, four principal parameters such as power, scanning speed, ratio of line gap, and number of line were selected as important factors. A Web-based design tool was developed to generate patterns of light guide panel, and the tool may assist the designer to develop optimized patterns. Topcon-BM7 was used for luminance measurement of each specimen 100mm$\times$100mm area. By Taguchi method optimized levels of each parameters such as 40W of power, 30mm/s of scanning speed, 100:50 ratio of pattern gap, and 90 line of pattern were found by Taguchi method.

• Nuclear Engineering and Technology
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• v.47 no.2
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• pp.139-147
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• 2015

Recently, severe accidents in nuclear power plants (NPPs) have become a global concern. The aim of this paper is to predict the hydrogen buildup within containment resulting from severe accidents. The prediction was based on NPPs of an optimized power reactor 1,000. The increase in the hydrogen concentration in severe accidents is one of the major factors that threaten the integrity of the containment. A method using a fuzzy neural network (FNN) was applied to predict the hydrogen concentration in the containment. The FNN model was developed and verified based on simulation data acquired by simulating MAAP4 code for optimized power reactor 1,000. The FNN model is expected to assist operators to prevent a hydrogen explosion in severe accident situations and manage the accident properly because they are able to predict the changes in the trend of hydrogen concentration at the beginning of real accidents by using the developed FNN model.

• Journal of Electrical Engineering and Technology
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• v.11 no.3
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• pp.609-617
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• 2016

Belt-driven Starter Generator (BSG) differs from other mild hybrid systems as the crankshaft of vehicle are not run off. Motor permits a low-cost method of adding mild hybrid capabilities such as start-stop, power assist, and mild levels of regenerative braking. Wound rotor synchronous motor (WRSM) could be adopted in BSG system for HEV e-Assisted application instead of the interior permanent magnet synchronous motor (IPMSM). In practice, adequate torque is indispensable for starter assist system, and energy conversion should be taken into account for the HEV or EV as well. Particularly, flux weakening control is possible to realize by adjusting both direct axis components of current and field current in WRSM. Accordingly, this paper present an off-line current acquisition algorithm that can reasonably combine the stator and field current to acquire the maximum torque, meanwhile the energy conversion is taken into consideration by losses. Besides, on account of inductance influence by non-uniform air gap around rotor, nonlinear inductances and armature flux linkage against current variation are proposed to guarantee the results closer to reality. A computer-aided method for proposed algorithm are present and results are given in form of the Look-up table (LUT). The experiment shows the validity of algorithm.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.10
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• pp.134-140
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• 2007

In recent years, power equipment and system standards have been increasing in both number and complexity. The standards that will soon be introduced to KOREA is the transmission system standards for harmonic emission limits assessing in distorting loads. Utility engineers, being under increasing time constraints, are turning more and more to software to quickly solve problems. This paper describes the methodology used to implement the above standards in Microsoft Excel in order to assist utility engineers to readily apply these standards in practical situations.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.6
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• pp.617-624
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• 2015

This paper describes the development of a wearable robot to assist the elbow muscle for use by elderly workers in aging societies. Various previously developed wearable robots have drawbacks in terms of their price, portability, and slow recognition of the wearer's intention. In this paper, emphasis is placed on the following features to minimize these drawbacks. The first feature is that an actuator is attached only at the elbow joint that withstands the highest moment during arm motion to reduce the weight, volume, and price of the robot and increase its practicality. The second is that operation of the wearable robot is divided into two modes, a tracking mode and a muscle strengthening mode, and the robot can automatically switch between these modes by analyzing the wearer's intention through the brachial muscle strength measuring device developed in this study. The assistive performance of the developed wearable robot is experimentally verified by motion tracking experiments without an external load and muscle strengthening experiments with an external load. During the muscle strengthening experiments, the power of the muscle of the upper arm is measured by a commercial electromyography (EMG) sensor. Motion tracking performance at a speed of $120^{\circ}/s$ and muscle assistance of over 60 % were obtained using our robot.

• ICROS
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• v.21 no.1
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• pp.31-36
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• 2015

운전자에게 편의성을 제공하는 차량의 주행관련 Advanced driver assist system (ADAS)에는 차량의 종방향과 횡방향 운동에 대한 제어기가 요구된다. 횡방향 제어를 위해서는 조향 시스템의 조향각 제어가 요구되는데 최근 구조적으로 간단하고 연비향상, 차량의 중량 감소, 빠른 응답성을 가지고 있는 전기적 파워 조향 (Electric power steering, EPS) 시스템이 자동차 산업에서 널리 사용되고 있다. 차량의 주행관련 ADAS를 사용하여 자율 주행 시 EPS 시스템은 상위 제어기에서 계산된 필요한 조향각을 추종 할 수 있도록 조향 핸들의 각 제어를 해야 한다. 그러나 일반적인 EPS 시스템은 운전자가 조향 핸들에 인가된 토크를 보조해 줄 수 있는 토크를 출력해 준다. 본 논문에서는 이러한 문제를 해결하는 방법들을 설명한다. 먼저 EPS 시스템의 기본 기능에 대해서 설명을 하고, 자율 추행 차량을 위한 조항 핸들의 각 제어를 위한 proportional-integral 제어, 슬라이딩 모드 제어 (Sliding mode control), 관측기 기반 비선형 댐핑 제어(Observer based nonlinear damping control) 등과 같은 다양한 기법의 제어 알고리즘들에 대한 방법들이 고찰되었다.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.236-237
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• 2011

고유가 시대의 도래와 화석연료의 소비를 줄일 수 있는 환경 친화적 자동차인 하이브리드 자동차의 도입이 일본, 미국 등을 중심으로 꾸준히 증가하고 있다. 이 중 마일드 하이브리드 시스템은 Idle Stop-Start, Launch Assist 및 회생 제동 등의 기능을 적용하여 연비개선의 효과를 갖고 있다. 본 논문에서는 기존 화석 연료를 사용하는 자동차에도 적용이 가능하며 2차 전지에 비해 수명이 긴 슈퍼 커패시터를 사용하여 MHEV용 5kW급 저압 인버터 시스템을 개발하였다.