• 전자공학회논문지B
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• 제32B권10호
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• pp.1347-1357
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• 1995

In this paper, we describe a modularized neuroclassifier for enhancing the recognition accuracy of mixed printed and handwritten numerals. This classifier combines four modularized subclassifiers using multi-layer perceptron module. The input of each subclassifier is comprised of a group of specialized feature sets. On applying this method to combining several subclassifiers for unconstrained handwritten numerals, the experimental result shows that the performance of individual subclassifier can be improved. In winner-take-all voting method, the result of subclassifier having the highest RF value is selected as the output. The generality of this classifier is tested with 1,080 printed and 3,000 handwritten numerals that was not shown in training the neural networks. Experimental results show 98.2% recognition rate. The typical recognition test with a threshold value(RF=1.5) has shown 97% recognition, 1% substitution and 2% rejection rates.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 춘계학술대회논문집
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• pp.168-171
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• 2003

Generally RF AGC (Roll Force Automatic Gauge Control) controls the roll gap using the variation of rolling force caused by the roll eccentricity and the entry thickness of material, but RE AGC takes the bad effect of the roll eccentricity. The Feed-forward (FF) AGC method, which controls the next stand roll gap by the estimation of the thickness variation due to skid mark is needed to supplement the shortage of RF AGC. In this paper, an adaptive filtering method which takes account of the kind of material, the final objective thickness and the rolling speed is proposed to predict skid mark thickness variation. In addition, an improved estimation method of control point using a speedometer and looper angle is suggested. Via on line test, the performance improvement of the suggested FF AGC method is verified.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2010년도 하계학술대회
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• pp.18-19
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• 2010

ATSC 방식의 지상파 디지털 TV 방송에서는 단일 주파수 망 구성 시 송신기들과 중계기들이 단일 주파수를 사용함에 따라 수신기에서 간섭 문제가 발생한다. 이를 해결하기 위하여 ATSC 권고에서는 각 송신기 및 중계기에 RF Watermark 방식의 식별 (TxID: Transmitter Identification) 신호를 할당하여 송신 및 중계 신호에 부가하여 전송하도록 권고하고 있다. 본 논문에서는 기존 DTV 신호에 부가되어 전송되는 RF Watermark 방식의 TxID 신호가 상용 DTV 수신기에 미치는 영향을 분산주파수망을 이용하여 실제 필드 테스트를 통해 살펴본다.

• 전산구조공학
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• 제9권1호
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• pp.125-132
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• 1996

본 연구는 총기대비용최소화기법에 의한 실용적이고 현실적인 해석모형을 제시하는데에 그 목적이 있으며, 주요목적중에 하나로서 철근콘크리트교량의 현장시험과 조사결과에 의해 도출된 저항계수(RF)라는 평가항목에 의해 현재 철근콘크리트부재들에 안전한 평가와 내하력을 결정하는데에 있다. 총기대비용최소화기법은 가정된 모델들의 신뢰성해석에 사용되며, 가정한 신뢰성모델과 신뢰성해석방법은 철근콘크리트부재들의 안전한 평가와 시스템계수에 적용되어진다.

• 정보와 통신
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• 제19권9호
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• pp.77-85
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• 2002

In this paper, we introduce an ADSRC(hdvanced DSRC) OFDM packet communication system which has been developed by ETRI. The ADSRC system is targeted to provide high terminal mobility, high data rate and seamless service in roadside environment for mobile office services. We discuss the requirements of the ADSRC communication system for mobile office services, and the system design specification to meet them with regard to air interface. The ADSRC packet communication systems consist of the MAC processor block, the OFDM packet modem block and the RF block. The MAC processor block handles medium access control and the test. The OFDM packet modem transmits data packets at up to 24Mbps adaptively and recovers the data from RF block. We describe the ADSRC packet communication system architecture and the ADSRC system protocol.

• The Korean Journal of Ceramics
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• 제3권4호
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• pp.257-262
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• 1997

Aluminum nitride(AIN) thin films were deposited on SiO$_2$/Si substrates by reactive sputtering for the application of SAW devices. The major deposition parameters such as pressure, nitrogen fraction, rf power, substrate distance were changed to find out the optimal condition for c-axis oriented thin films on an amorphous substrate. The effects of deposition parameters on the crystal structure, residual stress, and growth morphology of thin films were characterized by XRD, SEM, and TEM. The FWHM of (002) rocking curve of the films deposited at the proper condition was lower than 2.2$^{\circ}$(C=0.93$^{\circ}$). Cross-sectional TEM showed that self-aligned structure was developed just after slightly random growth at the initial stage. The frequency characteristics of test device fabricated from AIN thin films confirmed their piezoelectric property and applicability for SAW devices.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 심포지엄 논문집 정보 및 제어부문
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• pp.153-155
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• 2006

An automatic remote water measurement system was developed. This system sends automatic remote measured and collected water meters data automatically from the transmitter with CDMA modem through SK-Telecom network The water meter data are received through LAH TCP/IP and displayed as test file on IE(Internet Explorer) window. The existing water meters of mechanical type have so many problems to measure data. The person must visit the location of each water meters and write down the data records manually. In this system the RF module has attached each water meter Client/Server programs are developed by network socket programming.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.223-225
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• 2004

궤도회로방식을 대체할 무선통신을 이용한 열차제어방식의 경량전철시스템을 시험하기 위한 시험선로를 현재 건설하고 있다 열차제어시스템에서 사용하는 무선통신방식은 2.4[GHz]대역으로 국내 전파법에서 정의하고 있는 무선테이터통신시스템 및 아마추어 무선국의 주파수대역과 중복되고 있다 따라서 열차제어시스템용 무선통신장치에 의해서 시험선로 부근에서 사용가능성이 있는 무선데이터통신시스템 및 아마추어 무선국이 전파 간섭을 받고 있는지 확인하는 것이 필요하다. 본 논문에서는 경량전철시험선에 설치되는 무선통신장치의 배치위치 결정, 시험선지역의 전파환경측정결과 및 무선통신장치의 전파예측 등을 통하여 열차제어시스템용 무선통신장치의 사용가능성을 논하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1281-1282
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• 2008

Low cost TCO(Transparent Conductive oxide) thin films were prepared by 3" DC/RF magnetron sputtering systems. For the AZO preparation processes a 99.99% AZO target (Zn: 98 wt.%, $Al_2O_3$: 2 wt.%) was used. In order to verify feasibility of the AZO thin films to organic light emitting device (OLED) application, test organic light emitting device was fabricated based on AZO as TCO, TPD as hole transporting layer (HTL), Alq3 as both emitting layer (EML) and electron transporting layer (ETL), and aluminium as cathode, where the both ITO and AZO surfaces were treated using $O_2$ RF plasma. The I-V characteristics of the AZO/TPD/Alq3/Al OLEDs were evaluated. As the results, the performance of the OLEDs with AZO as transparent conducting anode could be useable.

• KSTLE International Journal
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• 제9권1_2호
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• pp.31-35
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• 2008

DLC (Diamond Like Carbon) films have predominant tribological properties like a high hardness, low friction and high chemical resistance; therefore, DLC films are applied in a wide range of industrial fields. This paper evaluated the characteristics of DLC films deposited on bearing steel with different hardness by RF-PECVD (Radio Frequency - Plasma Enhanced Chemical Vapor Deposition) method. Si-interlayer was deposited on bearing steel to improve adhesion strength by RF-Sputtering method. The DLC film structures were analyzed with Raman spectra and Gaussian function. Adhesion strength of DLC films was measured with a scratch tester. Friction and wear test were carried out with a ball-on -disc type to investigate the tribological characteristics. Experimental results showed that DLC films deposited on bearing steel under same deposition condition have typical structure DLC films regardless of hardness of bearing steel. Adhesion strength of DLC film is increased with a hardness of bearing steel. Friction coefficient of DLC film showed lower at the high hardness of bearing steel.