• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2009년도 정보 및 제어 심포지움 논문집
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• pp.48-50
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• 2009

This paper presents an IAQ(Indoor Air Quality) Monitoring System using equipments for measurement of fine Particle($PM1{\sim}PM10$), $CO_2$, VOCs(Volatile Organic Compounds), temperature and humidity for IAQ monitoring of subway station which millions of people use a day. The necessity of IAQ monitoring system is getting increased for more effective subway station monitoring in line with the recent government's regulation for IAQ is reinforcing. Subway Station is an unusual case. The structure of subway station is closed and complicated. Therefore when data of equipments are transferred, transmission error can happen occasionally. To prevent transmission error, an IAQ Monitoring System is needed the appropriate position and selection of equipments or sensor module. In addition IT(Information Technology) can be utilized like "WiBro(Wireless Broadband)" and "GateWay" for facilitate movement of data and construction of IAQ monitoring system of subway station.

• 반도체공학회 논문지
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• 제1권1호
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• pp.14-22
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• 2023

본 논문에서는 dual change-sensing 기법을 사용하여 내부 노드 변환을 최소화시킨 저전력 플립플롭 회로를 제안한다. 제안하는 Dual Change-Sensing Flip-Flop(DCSFF)은 데이터 변환이 존재하지 않는 경우, 기존에 존재하던 플립플롭들 중 동적 전력 소모가 가장 낮다. 65nm CMOS 공정을 사용한 측정 결과에 따르면, conventional Transmission Gate Flip-Flop(TGFF)와 비교하여 data activity 가 0% 와 100% 일때, 각각 98%와 32%의 감소된 전력 소모를 보였다. 또한 Change-Sensing Flip-lop(CSFF)과 비교하여 제안하는 DCSFF 는 30% 의 낮은 전력 소모를 보였다.

• Journal of Power Electronics
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• 제15권3호
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• pp.685-694
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• 2015

The power loss of the controllable switches in modular multilevel converter (MMC) HVDC transmission systems is an important factor, which can determine the design of the operating junction temperatures. Due to the dc current component, the approximate calculation tool provided by the manufacturer of the switches cannot be used for the losses of the switches in the MMC. Based on the enabled probabilities of each SM in an arm, the current analytical models of the switches can be determined. The average and RMS currents can be obtained from the corresponding current analytical model. Then, the conduction losses can be calculated, and the switching losses of the switches can be estimated according to the upper limit of the switching frequency. Finally, the thermal resistance model of the switches can be utilized, and the junction temperatures can be estimated. A comparison between the calculation and PSCAD simulation results shows that the proposed method is effective for estimating the junction temperatures of the switches in the MMC.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 춘계학술대회논문집
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• pp.51-55
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• 2007

In this paper Statistical Energy Analysis has been considered to predict high frequency air borne interior noise. Dash panel Insulation is major part to reduce engine excitation noise. Transmission loss and absorption coefficient are considered to predict dash insulation performance. Transmission lose is derived from coupling loss factor and absorption coefficient is derived from internal damping loss factor. Material Biot properties were used to calculate each loss factors. Insulation geometry thickness distribution was hard to measure, so FeGate software was used to calculate thickness map from CAD drawing. Each predicted transmission losses between conventional insulation and light weight insulation were compared with SEA. Transmission loss measurement was performed to validate each prediction result, and it showed good correlation between prediction and measurement. Finally interior noise prediction was performed and result showed light weight insulation system can reduce 40% weight to keep similar performance with conventional insulation system, even though light weigh insulation system has lower sound transmission loss and higher absorption coefficient than conventional system.

• 한국통신학회논문지
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• 제32권10B호
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• pp.644-654
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• 2007

지그비(ZigBee)는 무선 통신 표준 기술로서 이를 이용한 많은 서비스 응용들이 개발되고 있다. 이러한 서비스 응용들은 인터넷과의 연결을 위한 서비스 게이트웨이를 필요로 한다. 이러한 지그비 서비스 게이트웨이를 효율적으로 활용하기 위해서는, 지그비 서비스 게이트웨이는 프로파일에 따른 다양한 응용 메시지 변환, 새로운 노드의 추가/삭제에 따른 지그비 서비스의 추가/삭제에 대한 처리, 지그비 네트워크로의 불필요한 메시지 전달 차단과 같은 기능을 제공해야 한다. 본 논문에서는 이러한 기능들을 제공하는 새로운 형태의 지그비 서비스 게이트웨이, ZiGate를 제안한다. 제안하는 ZiGate는 지그비 네트워크와 연동하여 메시지 변환 모듈을 재설정하거나 불필요한 패킷을 차단하는 제공한다. 더불어, ZiGate는 프로파일 기반의 지그비 응용 메시지를 SOAP과 같은 텍스트 형과 이진 형을 갖는 인터넷 서비스 메시지로 상호 변환할 수 있는 기능을 동시에 제공한다. ZiGate 를 실제 구현하여 테스트베드에 설치 및 평가를 통하여, 본 논문에서는 제안하는 ZiGate가 효율적임을 보인다.

• 한국기계가공학회지
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• 제20권12호
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• pp.136-144
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• 2021

The purpose of this study was to develop and verify a precision transmission error measurement system for a gear pair. The transmission error measurement system of the gear pair was developed as a measurement unit, signal processing unit, and signal analysis unit. The angular displacement for calculating the transmission error of the gear pair was measured using an encoder. The signal amplification, interpolation, and transmission error calculation of the measured angular displacement were conducted using a field-programmable gate array (FPGA) and a real-time processor. A high-pass filter (HPF) was applied to the calculated transmission error from the real-time processor. The transmission error measurement test was conducted using a gearbox, including the master gear pair. The same test was repeated three times in the clockwise and counterclockwise directions, respectively, according to the load conditions (0 - 200 N·m). The results of the gear transmission error tests showed similar tendencies, thereby confirming the stability of the system. The measured transmission error was verified by comparing it with the transmission error analyzed using commercial software. The verification showed a slight difference in the transmission error between the methods. In a future study, the measurement and analysis method of the developed precision transmission error measurement system in this study may possibly be used for gear design.

• IEIE Transactions on Smart Processing and Computing
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• 제5권3호
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• pp.199-206
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• 2016

This paper describes a simple routing control system. We propose achieving high-speed data transmission without modifying the data frame configuration. To add a routing control signal, called the "labeling signal" in this paper, to the data frame, we use a frequency modulation technique on the transmitted frame. This means you need not change the data frame when you transmit additional signals. Using a prototype system comprising a field-programmable gate array and discrete elements, we investigate the system performance and devise a method to achieve high resolution. A three-channel routing control for a 10 Gb/s data frame was achieved, which confirms the advantages of the proposed system.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 춘계학술대회 논문집
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• pp.468-473
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• 2003

CCTV network has been implemented to transmit the image information of platfo gate and transfer section to local headquarters in the KNR(Korean National Railroa But. communication system for transferring image information around accident field has not been established yet. thus, at present implementation of communication equipment is necessary for dyn of unspecified accident to be transmitted to headquarters. Copper cable communication network is run by KNR, but it is processing installatio optics cable in connection with the implemental plan for high-speed network from n And, the capacity of communication channel will be guaranteed much more than een station and station, station and central headquarters when fiber optics cable is This study analyzes the image equipment of field for transmission and estimated m transmit image information of accident field to headquarters with using communicat ucture. And, the study considers implemental method of communication network for nce image transmission from dozens to hundreds kilometers.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 B
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• pp.1300-1302
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• 2003

CCTV network has been implemented to transmit the image information of platform, ticket gate and transfer section to local headquarters in the KNR(Korean National Railroad). But, communication system for transferring image information around accident field or wayside has not been established yet. thus, at present implementation of communication equipment is necessary for dynamic image of unspecified accident to be transmitted to headquarters. Copper cable communication network is run by KNR, but it is processing installation of optical cable in connection with the implemental plan for high-speed network from now on. And, the capacity of communication channel will be guaranteed much more than now between station and station, station and central headquarters when optical cable is completed. This study analyzes the image equipment of field for transmission and estimated matters to transmit image information of accident field to headquarters with using communication infrastructure. And, the study considers implemental method of communication network for long-distance image transmission from dozens to hundreds kilometers.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.1
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• pp.397-400
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• 2004

The design concept for 8kV light triggering thyristor(LTT) with integrated BOD was discussed here in detail. The trade-off between light triggering input source againsthigh dV/dt limitation has been treated via grooved P-base for gate design. The main application point used for high voltage DC transmission(HVDC) was represented.