• Journal of Korean Electronics
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• v.2 no.1
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• pp.62-63
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• 1982

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.3A
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• pp.319-323
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• 2007

In this paper, the automatic precision measurement of RF voltage has been done using the power and impedance standards [1] in the frequency range of 50 to 1000 MHz. A coaxial microcalorimeter and an automatic network analyzer were used for the determination of the RF-DC differences and the total uncertainty is about 1.0 %. A HP computer, a commodore computer and IEEE-488 interface bus were used for measuring the effective efficiency of thermistor mount and the RF-DC difference of thermal voltage converter, All processes of measurement were accomplished by self-developed program automatically.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.2208-2210
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• 2005

전문적인 지식이 없는 UHF 부분방전 측정장치 사용자를 위해 자동으로 측정된 신호로부터 GIS 내부의 결함을 추론할 수 있는 신경망회로 엔진을 연구하였다. 측정된 방전신호로부터 적절한 변수들을 계산하고 이를 신경망회로를 이용하여 미리 분류한 GIS 결함들 중 가장 유사한 결함을 자동으로 표현하는 기능을 엔진이 가지도록 하였다. 특히 본 엔진은 3상 일괄형 GIS나 GIS의 전압 위상에 동기되지 않은 부분방전 측정시스템에도 방전 원인을 잘 추론함을 실험을 통하여 확인하였다.

• Proceedings of the Korea Multimedia Society Conference
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• 2001.06a
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• pp.399-402
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• 2001

실기 중심의 수업에서 대부분의 학습자들이 반복되는 기능 습득으로 목표점에 도달할 수 있다. 이러한 행동주의적인 학습방법에도 기포적인 이론 즉 인지주의적인 학습이 뒷받침되어야 기능 습득이 효과적으로 된다고 본다. 특히 여기서 다루고자하는 전기회로 실습에서는 기기의 동작원리 및 동작되는 기기에 따라 변화되는 회로의 이해가 학습자에게 무엇보다 중요하다. 그러므로 실습에 사용되는 요소별 회로도의 이해를 돕기 위하여 동영상으로 된 회로분석도가 필요하다. 오늘간 일상 생활에서부터 각종 산업분야에 이르기까지 전기 분야가 차지하는 비중은 매우 크다. 전기분야는 전기이론, 전기기기, 전력, 자동제어, 전기응용, 전기측정, 전기실습 등 여러 분야가 있으나, 전기실습은 공업계 고등학교 학생들에게 곡 필요한 과목이며, 다른 과목의 이해를 돕게 하는 기초적인 요소이다. 여기에서는 이러한 전기실습의 효과를 높이기 위하여 동영상으로 된 회로 분석도를 작성하였다.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.96.2-96.2
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• 2010

EV(Electric Vehicle) 차량에서 BMS(Battery Management System) 은 모터에 공급되는 고전압 배터리의 충전상태를 감지하여 VCU(Vehicle Control Unit)에 전송하게 된다. VCU에서는 배터리의 충전상태를 확인하여 모터 구동 전략을 수립하여 각 제어기에 전송하게 된다. 위와 같이 EV에서 배터리 충전상태를 정확하게 감지하지 못한다면, 모터 구동을 위한 전략 수립에 많은 제약이 따르게 된다. 정확한 배터리 충전 상태를 감지하기 위해서는 배터리 각 셀의 전압/전류/온도 등을 측정하여 연산에 의해 결정된다. 그 중 셀 전압 측정 방식은 Photomos relay를 이용한 방식으로 하드웨어적인 오차에 ${\pm}$수십mV보다 더둑 더 정밀하게 측정할 수 있는 방법이 없었다. 하지만, 셀 전압 측정 정밀도를 향상시키기 위해 신규로 개발된 battery monitoring IC를 이용한 BMS의 H/W 개발에 대해 설명할 것이다. 또한, Monitoring IC를 이용한 BMS의 셀 전압 측정 정밀도를 얼마나 개선시킬 수 있는지에 대해 연구하였다.

• Journal of Korea Society of Industrial Information Systems
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• v.7 no.5
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• pp.190-194
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• 2002

The aim of development is system having convenient, cheap, reliable and better good measurements. The cozy environments in auto and architects is essentiable requirements. This study focuses on system developments of test equipment for better performance of noise protection in automobiles. Sound cards using makes easily to acquire the sound in each room, especially reduced the complexities of the circuits. The developed system have easily been measured and have characteristics of rapid mecanical response. The menu of rough scan method makes efficiently to test the shielding performance of auto rubber in whole frequency scales.

• Journal of Korean Ophthalmic Optics Society
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• v.6 no.1
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• pp.31-35
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• 2001

We have studied the auto-lensometer for several years in order to begin korean-made production of it and then developed the auto-lensmeter using with the personal computer. We introduce the most important principal of PSD device and the optical principal of measuring the power of the refraction of the lens by auto-lensometer and also explain the fabrication of the LED optical source system and PSD optical system. Finally, we found the power constant of our auto-lensmeter to be about 30 Diopter/mm.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.5
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• pp.787-794
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• 2001

In this paper, the development of large-signal model extractor for GaAs FET device through the Monolithic Microwave integrated Circuit(MMIC) is presented. The measurement program controlled by personal computer is developed for the processing of an amount of measured data, and the de-embedding algorithm is added to the program for voltage dropping as attached series resistance on measurement system. The small-signal model parameters are typically consisted of 7 elements that are considered as complexity of large-signal model and its the accuracy of the small-signal model is verified through comparing with measured data as varied bias point. The fitting function model, one of the empirical model, is used for quick simulation. In the process of large-signal model parameter extraction, one-dimensional optimization method is proposed and optimized parameters are extracted. This study can reduce the modeling and measuring time and can secure a suitable model for circuit.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.592-595
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• 2008

This paper presents development of automatic image quality register optimization system using mobile TFT-LCD (Thin Film Transistor-Liquid Crystal Display) driver IC and embedded software. It optimizes automatically gamma adjustment and voltage setting registers in mobile TFT-LCD driver IC to improve gamma correction error, adjusting time, flicker noise and contrast ratio. Developed algorithms and embedded software are generally applicable for most of the TFT-LCD modules. The proposed optimization system contains module-under-test (MUT, TFT-LCD module), control program, multimedia display tester for measuring luminance, flicker noise and contrast ratio, and control board for interface between PC and TFT-LCD module. The control board is designed with DSP and FPGA, and it supports various interfaces such as RGB and CPU.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.39 no.2
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• pp.104-115
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• 2002

Core is the main component of inductor. This core should be classified into around 10 classes according to the value of inductance and Q. The coil should be winded with the outer-boundary of this core by different number of turns. Theses kind of precise inductors would be required in the future environment which PCs and communication devices demand more high speed and lower voltage level. It would be quite unefficient that only one core is classified once a time. There, it will be developed so that 10 cores are classified simultaneously. For the operation of classifying 10 cores once in a time, suppose 10 test instruments could be used. In this case, it would take much cost since a test instrument Is expensive. So, by using only one test instrument, it is really more desirable that this system is developed. Each core classified by 10 different classes is to be stored into the corresponding box through the corresponding rubber hose. 10 cores are passed on a serial line and are placed on each testing slot. Here, each core located at each slot is tested, and then the bowl located on the top of a step motor is moved into the corresponding spot by rotating step motor with some angles. Each bowl connected with the corresponding box through rubber hose. Actually 100 hoses are connected, 10 step motors are rotated at 10 different angles, so the size is really so big, the shape of connecting 100 hoses is so complicated. Therefore it is anticipated that the system would be going to be easily out of ordered. In this paper the main purpose is to make several suggestions to be able to work well in these kinds of being affected by the abnormal operation of motors and the flow of cores.