• Journal of the Optical Society of Korea
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• v.15 no.3
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• pp.232-236
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• 2011

We analyze the linear equalizers used in optically amplified on-off-keyed (OOK) systems to combat chromatic dispersion (CD) and polarization mode dispersion (PMD), and we derive the mathematical minimum mean squared error (MMSE) performance of these equalizers. Currently, the MMSE linear equalizer for optical OOK systems is obtained by simulations using adaptive approaches such as least mean squared (LMS) or constant modulus algorithm (CMA), but no theoretical studies on the optimal solutions for these equalizers have been performed. We model the optical OOK systems as square-law nonlinear channels and compute the MMSE equalizer coefficients directly from the estimated optical channel, signal power, and optical noise variance. The accuracy of the calculated MMSE equalizer coefficients and MMSE performance has been verified by simulations using adaptive algorithms.

• Journal of the Korea Institute of Building Construction
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• v.12 no.3
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• pp.332-339
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• 2012

In this study, six mortar mixes were tested in order to examine the significance and limitations of hydrophilic fiber in terms of its capacity to enhance the tensile resistance of Hwangtoh mortar. Lyocell, polyamide and polyvinyl alcohol (PVA) fibers were selected for the main test parameters. The tensile capacity of mortars tested was evaluated based on the splitting tensile strength and the modulus of fracture, while their ductility was examined using the toughness indices specified in ASTM. Test results showed that the addition of lyocell and PVA fibers had little influence on the flow of the Hwangtoh mortars. To enhance the tensile capacity and toughness index of Hwangtoh mortar, it is proposed that fiber spacing above 0.0003 is required, regardless of the type of fiber.

• 한국HCI학회:학술대회논문집
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• 2008.02b
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• pp.91-96
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• 2008

Field trip education is frequently used in a primary education in Korea. However, it fails to provide specific research activities or feedback for students and lacks educational implication. We propose a mission-based field trip education using mobile phone. In this paper, we explain our design process, experiment at the zoo, and discuss the future work.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.1267-1274
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• 2005

The system which can manage and analyse the tunnel information in design and construction stage was developed through several years' research named ITIS(Intelligent Tunnel Information System). Now, the system is being modified and improved for the use of international tunnel construction information sharing. Some countries have their own management system for tunnel construction, and one of them, called DEST(Data Evaluation System for Tunneling), is adopted for the international cooperation for this research of development. The aimed system is operated under world wide web environment.

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1679-1681
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• 2001

In this paper, As the wavelet transform has the properties of multi-resolution analysis and time-frequency domain localization, application of wavelet transform is used at partial discharge(PD) signal detected by electromagnetic wave detection method to extract PD signal's various frequency component and its time domain. therefore we can analyzed PD signal's time-frequency domain simultaneously. On the other hand, using wavelet transform denoising process, inclued noise signal in detected PD signal is well elimiated. we can propose the true shape of PD signal.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.675-676
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• 2008

This paper presents adjustment of input order to improve clustering performance of ART1. We propose new method for On-line clustering which adjusts initial input data using buffer. We demonstrate the clustering performance of the proposed algorithm by testing it on Zoo data set from UCI and created artificial data set for simulation. Experimental results show that preposed method increases 7.8% of clustering performance than ART1 model on the average.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.8 s.350
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• pp.69-76
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• 2006

In this paper, we propose blind adaptation strategies for decision feedback equalizer (DFE) optimizing the operation mode between acquisitionand tracking modes based on adjustable soft decision devices. The proposed schemes select an optimal soft decision device to generate feedback samples for the DFE at a given noise to signal ratio, and apply corresponding adaptation rules which combine a blind infinite impulse response (IIR) filtering adaptation and the decision-directed least mean squared (DD-LMS) DFE adaptation. These adaptation approaches attempt to achieve not only smooth transition between acquisition and tracking of DFE but also mitigation of error propagation.

• Annual Conference on Human and Language Technology
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• 2001.10d
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• pp.302-309
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• 2001

말뭉치를 통한 통계적인 자연 언어 처리에 관한 연구가 다국어 처리 분야에서도 활발히 진행되고 있는 가운데, 본 논문에서는 병렬 말뭉치 구축 및 활용의 기본이 되는 문장 정렬을 위한 효과적인 방법을 제안한다. 먼저, 기존의 문장 길이를 이용한 방법을 한-영 문장 정렬에 적용해 보고, 길이 정보만을 이용했을 때의 한계점을 지적한다. 그리고, 사전과 품사 대응 확률을 이용한 단어 정렬을 통하여, 길이 기반의 정렬 방식이 갖는 문제점을 보완할 수 있는 방법을 제시한다. 실험을 통하여 제안한 방법이 길이에 기반한 방법에 비하여 높은 성능을 나타냄을 알 수 있었다. 또한 한-영 문장 정렬에의 어휘 정보 활용에 있어서 문제가 될 수 있는 요소가 어떤 것들이 있는지 알아본다.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1999.11a
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• pp.11-16
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• 1999

Discharge characteristics research for high voltage and large current electric machinery design, the development of ozonizer with high yield and efficiency for environment improvement, generation of plasma & laser and EMI EMC are research fields of Enersy & Environment Electromagnetic Laboratory(EEEL) in the school of electrical & electronic engineering of Yeungnam University. On this paper, we would like to introduce the discharge and ozone generation characteristics of ozonizers designed and manufactured by EEEL. After starting research for fluid gas discharge characteristics early in the 1980's, high voltage nozzle(HVN) type ozonizer, neon lamp(Nelamp) type ozonizer, ozone lamp(Olamp) type ozonizer and multi-discharge type ozonizer(MDO) have been investigated since 1990.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.7
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• pp.75-80
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• 2009

In this study, a Web server was constructed using LabVIEW's DataSocket, which makes possible acquisition, analysis, and saving in real time. The output value of the optical current sensor at the web server PC was measured and the output value was displayed using the Web browser of the client PC. DataSocket by LabVIEW makes the construction of a Web server easier than other languages and is compatible with other application programs. An optical current sensor was composed using a 1310 [nm] laser diode, and 9/125 [${\mu}m$] standard single mode optical fiber and was created to be a close type sensor. Data measurement using Web servers has the advantage of monitoring electric power systems at a great distance and can fuse IT technology and electric power systems. Also, this measurement uses inexpensive mounting and programming when compared to existing measurement equipment allowing the construction of a measurement system in any situation or surrounding.