• 한국통신학회:학술대회논문집
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• 한국통신학회 1982년도 추계학술발표회논문집
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• pp.1-13
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• 1982

Nowadays , The function of telecommunication contributes to maintaining the peace of the world, and the internetional cooperation in the communication field can not be emphasized too much. The pioneers in telecommunication field devoted their lives to the Infinite love for humanity. However, the modern communication system in our country was initiated, in the later part of the Lee-Dynasty, not for the international cooperation but for the invasive avarices of the neighbouring nations such as Japan and China. The true internationaL cooprration should be based on the love of humanity and the peace of the world such as the pionreers. This paper proposes to resoarch the historic process of initiation and development of the international organs relating to telecommunication as well as the intenational elecomunication network. Finally, I will make the foIlowing suggestions for the promotive direction of the true international coonperation, 1. Intensification of the radio administrative power 2. Promotion of the international cooperation on the man-power and economy in telecommunication field. 3. Establishment and Adjustment of the research institutes Of telecommunication. 4. Establishment of the world telecommunication network for world-wide peace

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 하계종합학술대회 논문집(1)
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• pp.19-22
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• 2004

This paper implemented 2.14GHz band Adaptive Hybrid Doherty (AHD) amplifier, as well as, wished to improve the high power characteristics and efficiency by composing bias adjustment circuit with LDMOS. Finally, through CAE, confirmed that AHD amplifier have superior performance than hybrid balanced amplifier. Superior characteristics of AHD amplifier is expected to affect immensely in amplifier field hereafter.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1991년도 추계학술대회 논문집 학회본부
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• pp.231-233
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• 1991

This paper discribes a study on the switching character of MOS-GTO and the design of gate drive circuit. Chopping power supply converter, synchronious and asyncronious motor speed adjustment, inverter, etc., needs low drive energy "high frequency" switches. To fulfill these need, switches must have rapid switching time and insulated gate control. MOS-GTO structure is well suited to these constraints. The power switch is serial installation of a GTO thyrister and a MOS Transistor. The gate of the GTO is linked to positive pole of the cascode structure via a MOS high voltage transistor and ground via a transient absorber diode. This high performance MOS-GTO assembly considerably increases the strength which facilitate the drive of GTO thyristers.

• 전력전자학회논문지
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• 제11권2호
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• pp.184-191
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• 2006

본 논문은 HVDC 시스템의 고장분석과 제어게인 파라미터정정에 대한 내용을 다루고 있다. 본 논문에서 다루는 내용은 정류실패에 의한 과전압에 의해서 유발된 실제의 케이블 사고를 다룬다. 그리고 고장을 분석하기 위해서 샘플링 타임이 50us인 정밀 PSCAD/EMTDC Model을 이용하였으며, 최종적으로 분석결과에 의해 HVDC시스템의 제어 파라미터가 정정되었다.

• Journal of Advanced Marine Engineering and Technology
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• 제27권6호
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• pp.696-703
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• 2003

A photovoltaic power generation system is an infinite and clean energy system. Recently. because of the realization of high efficiency and low cost PV modules, the studies on the PV system have extensively increased. In this paper. we present an online scheme for parameter estimation of solar cell, based on the model adjustment technique and a real-coded genetic algorithm(RCGA). The ideal diode model and the diode model with series and shunt resistors are used to estimate their parameters, Simulation works using field data in the form of a V-I characteristic curve are carried out to demonstrate the effectiveness of the proposed method.

• 전력전자학회논문지
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• 제9권6호
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• pp.584-591
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• 2004

기존의 아날로그 점호각 제어방법은 op-amp, 저항 및 커패시터 등을 사용하였기 때문에 아날로그 회로의 특성상 온도와 소자의 경년변화에 따라 파라메타 값이 변동하며 전원전압의 노이즈에 민감하게 반응하는 단점이 있었다. 따라서 본 논문에서는 디지털 사이리스터 점호회로를 이용하여 기존의 아날로그 점호회로 장점인 선형특성, 그리고 전원전압 노이즈 온도 및 갱년변화에 의한 수동소자의 변동에 강인한 특징을 갖는다. 또한 디지털 시스템의 장점인 연산기능을 이용하여 전원전압의 불평형 발생시 디지털 시스템의 특징인 연산기능을 이용하여 전원전압의 불평형을 검지하고 보상알고리즘을 도입하여 언제나 리플이 없는 출력전압을 만들어내어 사이리스터 전력변환 시스템의 안정적인 운전이 가능하게 할 수 있는 장점이 있다.

• 한국통신학회논문지
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• 제7권4호
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• pp.135-150
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• 1982

Nowadays, The function of telecommunication contributes to maintaining the peace of the world, and the international cooperation in the communication field can not be emphasized too much. The pioneers in telecommunication field dvoted their lives to the infinite love for humanity. However, the modern communication system in our country was initiated, in the later part of the Lee-Dynasty, not for the international cooperation but for the invasive avarices of the neighbouring nations such as Japan and China. The true international cooperation should be based on the love of humanity and the peace of the world such as the pioneers'. This paper proposes to resarch the historic process of initiation and development of the international organs relating to telecommunication as well as the international telecommunication network. Finally, I will make the following suggestions for the promotive direction of the true international cooperation. 1. Intensification of the radio administrative power. 2. Promotion of the international cooperation on the man-power and economy in telecommunication field. 3. Establishment and adjustment of research institutes of telecommunication. 4. Promotion of space communications. 5. Establishment of the world telecommunication network for world-wide peace.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 합동 추계학술대회 논문집 정보 및 제어부문
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• pp.176-179
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• 2001

A portable bio-signal measurement system for 24-hours continuous health monitoring of the elderly and the disabled is presented. The measurement system has the functions of acquisition of various bio-signals such as ECG, EMG and EEG, wireless data transmission/receive and adjustment of parameters such as gain and cut-off frequency. The data is sent to a host computer or other device via a Bluetooth. The design targets of the developing system for volume and power consumption are $20{\times}30{\times}5(mm^3)$ and 8mW.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(2)
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• pp.565-568
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• 2003

The conventional analog-based firing circuit can be implemented by comparing a linearly decreasing periodic sawtooth waveform synchronized to the ac line, with a voltage corresponding to the desired converter delay angle. This circuit requires a large number of components (resistance and capacitor) and careful adjustment of the synchronization circuity In this paper a novel firing circuit is proposed for thyristor switch is elements. The proposed circuit is implemented on the basis of the analog cosine method using FPGA and microprocessor.

• 한국해양공학회지
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• 제21권3호
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• pp.1-7
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• 2007

In this study, the heat balance test of an engine was conducted, and the heat released to coolant is measured and corrected using a power adjustment factor for high fuel temperature to simulate heat rejection of the engine. An engine-converter matching simulation program which can compute the engine speed, transmission output speed, transmission input and output power is developed from the vehicle, transmission and engine performance curve. With this information and the engine heat rejection characteristics, the engine and transmission heat rejection rates can be determined at given condition. In analyzing the air mass flow, a sub program computing the air mass flow rate from the equation of the pressure balance between cooling fan static pressure rise and pressure losses of cooling components is developed.