• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1998.06a
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• pp.42-45
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• 1998

In this paper, a fuzzy control technique using adjustable scale factors and Lyapunov Function for the precise position control of DC servo system is introduced. The suitable scale factors were selected and the stable control input using the stability theory of Lyapunov function cam be applied. Therefore, the controlled system have the robustness against disturbances and can be stabilized because of reinforced adaptivity. This proposed fuzzy controller is implemented on a 80586 micro-computer which have of fuzzy inference routine part, manipulating part of scale factors and DT-2801 data aquisition board.

• Journal of Educational Research in Mathematics
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• v.11 no.1
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• pp.223-238
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• 2001

Decimal fractions are the practical system of notations representing real numbers. The set of decimal fractions with the definition of comparison of decimal fractions and the identification of their double representations is essentially the field of real numbers. Therefore, we have to clarify the concept of decimal fractions. However, there are problematics that the aquisition of the concept of decimal fractions is not easy. In this paper, we attempt to eradicate the problematics relevant to the acquisition of decimal fractions discussed above and find the desirable direction of instruction of meaning for mathematical symbols: The case of decimal fractions. In J. Hiebert & decimal fractions. First of all, we clarify the essence of them - ratio, operator and linearity. And we compare and analyse the theories about decimal fractions of Resnick, Drexel, Brousseau and Hiebert and the contents of texts about decimal fractions in Korea. Finally, we suggest the efficient instruction methods which are faithful to the essence of decimal fractions and choose some methods among them to plan the classroom instruction and implement the methods in the classroom.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.664-669
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• 2002

Intertidal zone (tidal flat) is a place which is sometimes dry and sometimes wet depending on the tidal rhythm. Direct measurement of topography in the intertidal zone is very difficult to be achieved. The interface between wet and dry parts in the tidal flat, which can be identified from near infrared band of satellite image, is a 'depth contour' which corresponds to the sea level at the time of satellite pass. Aquisition of topography data in tidal flat is possible by combining various techniques such as (1) identification of the interface between wet and dry parts, (2) GCP correction of satellite image, and (3) realtime prediction of sea level elevation at the time of satellite pass. The algorithm was successfully applied in obtaining topography (bathymetry) data in the intertidal zone of Asan Bay in the west coast of Korea from 26 satellite images. The method is expected to be very efficient in making bathymetry data base in the western and southern parts of Korea where tidal flats are well developed in wide regions.

• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2405-2407
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• 1999

In recent, the application of polymeric insulators for outdoor is significantly increasing. These materials have shown good performance in service, but had disadvantages under long-term exposure to contamination and moisture, resulting in some problems. Thus, this study concentrated on the development of technique evaluating the insulating status. Experiment was referred to lEC publ. 587, with data aquisition system to monitor leakage current. The components of leakage current investigated were waveform and 3rd harmonic. FFT was conducted for the analysis of harmonic components. The distortion of waveform with application time of voltage was evident, and so the 3rd harmonic component.

• IE interfaces
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• v.15 no.4
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• pp.374-381
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• 2002

In this paper, we design and implement a real-time route guidance system(RGS) in large-scale networks. Coupled with the well-known mathematical routing algorithms, we devise an RGS for knowledge aquisition and self-learning ability within the framework of the expert system. Through off-line construction of database, on-line treatment of unexpected traffic accidents, etc., the developed RGS can provide drivers with good quality real-time routing information. The practical effectiveness of the proposed system is demonstrated in terms of response time and route appropriateness.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2006.06a
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• pp.119-122
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• 2006

홍채인식 시스템의 성능은 입력된 눈 영상으로부터 정확한 홍채 영역의 검출 및 효율적인 홍채코드의 생성 등의 영향을 받으나, 이를 위해서는 입력된 눈 영상에서 홍채 패턴이 선명해야 한다는 선행 조건이 존재한다. 초점이 맞지 않아 흐리게 나온 영상 눈을 감은 영상, 속눈썹에 의해 홍채영역이 가려진 영상, 움직임에 의해 블러링된 영상, 또는 홍채가 아닌 속눈썹 등의 다른 부분에 초점이 맞춰진 영상 등에서는 선명한 홍채 패턴을 얻을 수 없으므로 전체 인식 성능을 떨어뜨리는 요인이 된다. 그러므로 이러한 영상들을 자동으로 걸러내 제거해주는 눈 영상 화질 측정 방법이 필요하다. 본 논문에서는 눈 영상의 초점이 잘 맞는지 측정하는 방법을 제안하고 자체적으로 획득한 데이터베이스를 이용해 이를 테스트하였다.

• Journal of Korean Society for Quality Management
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• v.30 no.3
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• pp.111-119
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• 2002

Gears are essential elements for mechanical power transmission. Geometric precision is the main factor for characterizing gear grade and qualify. Gear pitch is one of the crucial measurements, which is defined as a distance between two adjacent gear teeth. It is well-known that variability in gear pitches may causes wear-out and vibration noise. Therefore maintaining pitch errors at a low level plays a key role in assuring the gear quality to customers. This paper is concerned with a case study, which presents a computerized system for Inspecting pitch errors in a gear machining process. This system consists of a PC and window-based programs. Although the start and stop is manually accomplished, the process of measuring and analyzing pitch data is automatically conducted in this system. Our purpose lies in reducing inspection cost and time as well as Increasing test reliability. Its operation is briefly illustrated by example. Sometimes a strong autocorrelation is observed from pitch data. We also discuss a process monitoring scheme taking account of autocorrelations.

• Journal of the Korean Society of Systems Engineering
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• v.5 no.1
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• pp.43-48
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• 2009

Korean Tilting trains have been tested on conventional lines since the beginning of 2007 for evaluating its reliability. We achieved some major performance tests which are the maximum operation speed, 180km/h test and the maximum curves increasing speed, over 30 percentage comparing with non-tilling operation train. In order to analysis reliability data of tilting train, we have used the special system engineering frame with interfacing between component suppliers effectively. And also we have developed the data aquisition system which consists of monitor, sensors and depot computer etc. As a results of calculation, until now we realized that the reliability are getting more increasing than starting point of running field test.

• Journal of Intelligence and Information Systems
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• v.7 no.2
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• pp.65-81
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• 2001

This paper presets the process of knowledge aquisition by partitioning the phase of analysis & design for knowledge-base module construction of Expert System into five steps to derive rule systematically. Also, this paper presents the process and the task that knowledge engineer must do work each step. The knowledge-base module of STAFS expert system was constructed by considering the destruction rate and the commander\`s intention using the proposed rule derivation methodology.

• Proceedings of the Korea Contents Association Conference
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• 2011.05a
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• pp.157-158
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• 2011

건설현장의 온도, 습도, 조도, GPS 위치정보 및 대기중의 CO2 농도 등의 환경 데이터는 공사 진행에 따라 설계 변경 또는 개선 등의 필요성이 있는 경우에 유용하게 이용될 수 있다. 건설현장에서의 이러한 환경 데이터를 획득 및 처리하기 위한 하나의 USN 시스템을 구현하여 본사 또는 해당 부서에 필요한 시간에 온라인으로 제공함으로써 현장의 현황파악을 위한 기초 자료 제공은 물론 시간과 노력을 줄일 수 있으며 특히 공사현장이 먼 거리에 떨어져 있을수록 더욱 유용하게 적용될 수 있다. 온도, 습도, 조도, GPS 위치정보는 설치 장소에 따라 적절한 해당 측정 정보를 제공하였으며 대기중의 CO2 농도는 자동차 또는 혼잡한 시내 거리 등에서 조금 높은 수치를 보였다.