• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.22 no.4
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• pp.391-400
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• 2004

Railway curved zone have crucial effects on the speed of train. Length of transition curve is one of the important factor for alignment compatibility estimation in this sections, this value is decided by running speed and Cant. In this study, the extension method of transition curve is evaluated, based on the alignment of Jang Hang-Line, investigated field conditions of the sections in the curves exist. This research result show that changing of transition curve was proved by necessary to approximately two thirds of the curved sections, and method of fixing central point of track centerline and changing radius of curvature minimize the maximum shift in track centerline and deviation of radius, and also may be effective method for alignment suitability and speed up in case overall improvement is difficult.

• Proceedings of the Korean Statistical Society Conference
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• 2005.05a
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• pp.1-6
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• 2005

SAS의 PROC MIXED는 ANOVA 추정량보다 더 다양한 잔차최대우도추정법 또는 최대우도추정법으로 모수들을 추론할 수 있다. 혼합모형에 속하는 불균형중첩오차구조를 갖는 선형회귀모형에서 랜덤효과에 해당되는 그룹간의 분산과 고정효과에 해당되는 회귀계수들에 대한 신뢰구간을 구하기 위하여 대표본인 경우와 소표본인 경우에 대하여 PROC MIXED를 사용한다. 시뮬레이션을 실행한 결과, 대표본인 경우에는 모수들의 신뢰구간을 구하기 위하여 PROC MIXED를 활용할 수 있지만, 소표본인 경우에는 PROC MIXED를 사용할 경우, 그룹간 분산과 회귀계수 가운데 하나인 절편항에 대한 신뢰구간은 시뮬레이터된 신뢰계수가 명시한 신뢰계수를 지키지 못하는 것을 보인다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.8
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• pp.2119-2132
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• 1996

This paper proposes four approaches for approximately realizing nonlinear mappling of interval vectors by neural networks. In the proposed approaches, training data for the learning of neural networks are the paris of interval input vectors and interval target output vectors. The first approach is a direct application of the standard BP (Back-Propagation) algorithm with a pre-processed training data. The second approach is an application of the two BP algorithms. The third approach is an extension of the BP algorithm to the case of interval input-output data. The last approach is an extension of the third approach to neural network with interval weights and interval biases. These approaches are compared with one another by computer simulations.

• Journal of Advanced Navigation Technology
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• v.26 no.6
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• pp.504-509
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• 2022

In this paper, we deal with the stability condition of linear time-varying interval discrete systems with time-varying delays and unstructured uncertainty. For the time-varying interval discrete system which has interval matrix as its system matrices, time-varying delay time within some interval value and unstructured uncertainty which can include non-linearity and be expressed by only its magnitude, the stability condition is proposed. Compared with the previous result derived by using a upper bound solution of the Lyapunov equation, the new result is derived by the form of simple inequality based on Lyapunov stability condition and has the advantage of being more effective in checking stability. Furthermore, the proposed condition is very comprehensive, powerful and inclusive the previously published conditions of various linear discrete systems, and can be expressed by the terms of magnitudes of the time-varying delay time and uncertainty, and bounds of interval matrices. The superiority of the new condition is shown in the derivation, and the usefulness and advantage of the proposed condition are examined through numerical example.

• Journal of Advanced Navigation Technology
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• v.25 no.6
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• pp.551-556
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• 2021

In this paper, we deal with the stability condition of linear interval discrete systems with time-varying delays and unstructured uncertainty. For the interval discrete system which has interval matrix as its system matrices, time-varying delay time within some interval value and unstructured uncertainty which can include non-linearity and be expressed by only its magnitude, the stability condition is proposed. Compared with the previous result derived by using a upper bound solution of the Lyapunov equation, the new results are derived by the form of simple inequality based on Lyapunov stability condition and have the advantage of being more effective in stability application. Furthermore, the proposed stable conditions are very comprehensive and powerful, including the previously published stable conditions of various linear discrete systems. The superiority of the new condition is proven in the derivation process, and the utility and superiority of the proposed condition are examined through numerical example.

• Journal of Advanced Navigation Technology
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• v.27 no.6
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• pp.871-876
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• 2023

In this paper, we deal with the stable conditions when two uncertainties exist simultaneously in a linear discrete time-varying interval system with time-varying delay time. The interval system is a system in which system matrices are given in the form of an interval matrix, and this paper targets the system in which the delay time of these interval system matrices and state variables is time-varying. We propose the system stability condition when there is simultaneous unstructured uncertainty that includes nonlinearity and only its magnitude and uncertainty in the system matrix of delayed state variables. The stable bounds for two types of uncertainty are derived as an analytical equation. The proposed stability condition and bounds can include previous stability condition for various linear discrete systems, and the values such as time-varying delay time variation size, uncertainty size, and range of interval matrix are all included in the conditional equation. The new bounds of stability are compared with previous results through numerical example, and its effectiveness and excellence are verified.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.12
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• pp.2521-2526
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• 2011

This paper proposes a speaker recognition algorithm using a perceptron neural network and LPC (Linear Predictive Coding) cepstrum coefficients. The proposed algorithm first detects the voiced sections at each frame. Then, the LPC cepstrum coefficients which have speaker characteristics are obtained by the linear predictive analysis for the detected voiced sections. To classify the obtained LPC cepstrum coefficients, a neural network is trained using the LPC cepstrum coefficients. In this experiment, the performance of the proposed algorithm was evaluated using the speech recognition rates based on the LPC cepstrum coefficients and the neural network.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2004.03a
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• pp.551-557
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• 2004

미래의 텔레매틱스(telematics)환경에서 차량항법과 관련된 주요 핵심 기술은 동적 경로 안내 이외에 차량 자체의 지능화를 통해 운전자에게 주행 중인 도로에서 급경사, 급커브 구간에 대한 정보를 사전에 경고함으로써 사고를 방지하는 운전자 보조 및 경고 시스템(driver assistance and warning system) 구현으로 전망되고 있다. 이와 같은 기술이 구현되기 위해서는 현재 차량항법용 수치도로지도에서 도로의 단순 위치정보만으로는 불가능하며 도로의 곡선구간에서 평면 곡선반경과 같은 도로의 선형설계요소에 대한 정보가 필수적이다. 따라서 본 연구에서는 현재 전국적으로 구축되어있는 1/1000 수치지도의 도로중심선을 이용하여 실제 도로의 평면 선형설계요소를 자동으로 추출하기 위한 알고리즘을 개발하였고 이를 GUI 환경의 프로그램으로 구현함으로써 기존 도로의 정확한 평면 선형정보를 경제적이면서 효율적으로 획득할 수 있게 되었다.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.110.2-110.2
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• 2016

4세대 방사광가속기는 0.1nm급 X-선 자유전자레이저(X-ray Free Electron Laser : XFEL) 광원을 빔라인 사용자들에게 제공하기 위하여 2011년 건설을 시작하였고, 2015년부터 장치를 설치하기 시작했으며 현재 건설 완료단계에 이르러 있다. 이 장치에서 진공시스템은 10-11 mbar의 초고진공이 요구되는 전자빔 발생장치인 RF Gun을 포함하는 입사장치구간(Injector)과 전체길이 800 m에 이르는 전자빔을 가속시키는 선형가속기구간(Linac) 그리고 결맞음 방사광을 발생시키는 언듈레이터구간으로 나눌 수 있다. 본 논문에서는 각 구간별 진공시스템에 대한 건설 현황에 대하여 보고하고자 한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.12C
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• pp.1262-1267
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• 2005

Elliptical basis function (EBF) neural network works stably under high-level background noise environment and makes the nonlinear processing possible. It can be adapted real time VAD with simple design. This paper introduces VAD implementation using EBF and the experimental results show that EBF VAD outperforms G729 Annex B and RBF neural networks. The best error rates achieved by the EBF networks were improved more than $70\%$ in speech and $50\%$ in silence while that achieved by G.729 Annex B and RBF networks respectively.