• Magazine of the Korea Concrete Institute
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• v.16 no.1 s.78
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• pp.49-56
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• 2004

• Journal of Electrical Engineering and Technology
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• v.11 no.5
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• pp.1395-1403
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• 2016

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1993.04a
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• pp.203-204
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• 1993

• Journal of Korea Multimedia Society
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• v.8 no.6
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• pp.768-775
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• 2005

For sign languages are main communication means among hearing-impaired people, there are communication difficulties between speaking-oriented people and sign-language-oriented people. Automated sign-language recognition may resolve these communication problems. In sign languages, finger spelling is used to spell names and words that are not listed in the dictionary. There have been research activities for gesture and posture recognition using glove-based devices. However, these devices are often expensive, cumbersome, and inadequate for recognizing elaborate finger spelling. Use of colored patches or gloves also cause uneasiness. In this paper, a vision-based finger spelling recognition system is introduced. In our method, captured hand region images were separated from the background using a skin detection algorithm assuming that there are no skin-colored objects in the background. Then, hand postures were recognized using a two-dimensional grid analysis method. Our recognition system is not sensitive to the size or the rotation of the input posture images. By optimizing the weights of the posture features using a genetic algorithm, our system achieved high accuracy that matches other systems using devices or colored gloves. We applied our posture recognition system for detecting Korean Sign Language, achieving better than $93\%$ accuracy.

• International Journal of Air-Conditioning and Refrigeration
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• v.8 no.2
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• pp.39-50
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• 2000

Thermodynamic cycle analysis is presented to estimate the maximum liquefaction rate of hydrogen for various systems using a Gifford-McMahon(GM) cryocooler. Since the present authors` previous experiments showed that the gaseous hydrogen was liquefied approximately at the rate of 5.1 mg/s from the direct contact with a commercial two-stage GM refrigerator, this study has been proposed to predict how much the liquefaction rate can be increased in different configurations using the GM cooler and with improved heat exchangers. The optimal operating conditions have been analytically sought with real properties of normal hydrogen for the Linde-Hampson(L-H) system precooled by single-stage GM, the direct-contact system with two-stage GM, the L-H system precooled by two-stage GM, and the direct-contact system with helium GM-JT (Joule-Thomson). The maximum liquefaction rate has been predicted to be only about 7 times greater than the previous experiment, even though the highly effective heat exchangers may be employed. It is concluded that the liquefaction rate is limited mainly because of the cooling capacity of the commercially available GM cryocoolers and a practical scale of hydrogen liquefaction is possible only if the GM cooler has a greater capacity at 70-100 K.

• Journal of the Korean Society for Nondestructive Testing
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• v.28 no.4
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• pp.358-363
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• 2008

Ultrasonic nonlinearity has been considered as a promising method to evaluate the micro damage of material; however, its magnitude is so small that its measurement is not easy. Thus, in this study, we investigate the effects of such experimental system dependent factors in the measurement of ultrasonic nonlinear parameter by using contact PZT transducer. Experimental results showed that the effect of system dependent nonlinearity is reduced when the contact pressure and transducer input voltage are sufficiently large. These results will be very useful to find out the proper experiment condition to measure rather accurate nonlinear parameter.

• Proceedings of the KSRS Conference
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• v.2
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• pp.872-875
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• 2006

This paper introduces the result of a 3D climbing navigation system development which is based on PDA. In the visual viewpoint, this system is better than conventional systems that were developed 2D based. In addition, the proposed system was developed so that it could become compatible with these systems. In this paper, we will illustrate as the functional viewpoint than technical description about the system development.

• ETRI Journal
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• v.31 no.4
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• pp.463-465
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• 2009

In this letter, we present an event stream processing system that can evaluate a pattern query for a data sequence with predicates. We propose a pattern query language and develop a pattern query processing system. In our system, we propose novel techniques for run-time aggregation and negation processing and apply our system to stream data generated from vehicles to monitor unusual driving patterns.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.1028-1032
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• 2005

Due to excessive city's Traffic jam, which an energy and pollution problem of metropolis have risen seriouly, Many industrialized countries have developed many kind of new transportation system for the purpose of substituting the mass traffic. Maglev system has began the revenue operation from Japan and China recently and it is beginning highlighted the new system. We examined specification to be improved in the system and safety of maglev.

• Proceedings of the KIEE Conference
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• 2007.10c
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• pp.68-70
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• 2007

본 논문에서는 전력용변압기의 예방진단 IED(Intelligent Electronic Devices) 개발에 대하여 기술하였다. 유입식 전력용변압기의 예방진단을 위한 IED 및 제반 시스템 구성, IED에 탑재된 알고리즘에 대하여 설명한다. 또한 시스템내부의 통신형태 및 HMI 화면구성에 대하여 소개한다.