• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 추계종합학술대회 논문집
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• pp.1133-1136
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• 1998

본 논문에서 최적화이론이란 이 논문에서 두 개의 회로를 비교하고 트랜지스터의 개수를 적게 사용하여 전력소비를 줄일 수 있었고, 면적을 적게 축소하였다. 그리고 입출력에서 사용하는 제어는 크게 두 개로 나누었다. 첫 번째로 인버터를 사용해서 순차적으로 진행하도록 한 파이프라인의 회로를 설계하였고, 두 번째로 논리회로를 이용해서 n개의 MUX를 동시에 동작하도록 제어하였다. 두 개의 회로에서 트랜지스터의 개수와 반도체 칩의 면적 그리고 소비전력을 비교하여본다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1999년도 가을 학술발표회 논문집
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• pp.201-208
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• 1999

The NATM(New Austrian Tunnelling Method) has been used for tunnelling since 1980's. But Collapses of tunnel under construction take place frequently, especially at urban areas because of adjacent buildings, underground conduits and traffic loads. This paper is a case study on the reinforcement method of subway tunnel at urban areas. In this study, ground inspection, geological investigation, laboratory test and numerical analysis by means of FDM program were carried out. The tunnel excavation was stopped because of over excessive brake of tunnel crown and shotcrete was installed to prevent deformation of adjacent ground as the temporary method. From the result of field survey and geological investigation, it is found that the soft weathered soil was distributed to the ground of tunnel invert unlike original investigation. The results of the analysis and the study show that the SGR(Space Grouting Rocket) method and Umbrella method can be applied for the stability of tunnel excavation and in addition the reinforcement of concrete lining is required for long-term stability of tunnel.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제19권1호
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• pp.61-79
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• 2015

This study discussed about how pseudo-thinking process actually occurs in the mind of the students, used Piaget's frame work of the assimilation and accommodation process. The data collection is conducted using Think-Out-Loud (TOL) method. The study reveals that pseudo thinking process of covariational reasoning occurs originally from incomplete assimilation, incomplete accommodation process or both. Based on this, three models of incomplete thinking structure constructions are established: (1) Deviated thinking structure, (2) Incomplete thinking structure on assimilation process, and (3) Incomplete thinking structure on accommodation process.

• Journal of applied mathematics & informatics
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• 제6권2호
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• pp.433-446
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• 1999

Let G denote either of the groups $GL_2(q)$ or $SL_2(q)$. The mapping $theta$ sending a matrix to its transpose-inverse is an auto-mophism of G and therefore we can form the group $G^+$ = G.<$theta$>. In this paper conjugacy classes of elements in $G^+$ -G are found. These classes are closely related to the congruence classes of invert-ible matrices in G.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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• pp.695-697
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• 2006

Elshayal $Smart{\copyright}$ software is an almost First Arabian GIS $software{\copyright}$ which completely developed by Arabian developers team and independent of any commercial software package. The software current Features are View and Edit shape files, build new layers, add existing layers, remove layers, swap layers, save layers, set layer data sources, layer properties, zoom in & zoom out, pan, identify, selecting features, invert selection, show data table, data query builder, location query builder, build network, find shortest path, print map, save map image, copy map image to clipboard, save project map, edit move vertex, edit move features, snap vertexes, set vertex XY, move settings, converting coordinate system, applying VB script, copy selected features to another layer, move selected features to another layer, delete selected features, edit data table, modify table structure, edit map features, drawing new features, GPS tracking, 3D view, etc... The software expected Features are: Viewing raster image and image geo-referencing, read other map formats such as DXF Format and Tiger Line Format.

• 대한전기학회논문지:전력기술부문A
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• 제51권12호
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• pp.624-629
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• 2002

This paper presents the first Simulation model using EMTDC program to analyze the electrified train voltage distribution characteristics in ac auto-transformer 1110 railroads. In general, all of the electrified train supply system has the characteristics that the train supply line is a naturally non-symmetrical and unbalanced system. Also, it is needed to model the Scott transformer which invert the balanced 3-phase quantity into 2-phase. Therefore, the general simulation methodology using previous simplified equivalent circuit or RMS based program can't obtain the accurate results to reflect the real-time operation because these methodology is basically assumed on completely 3-phase balanced system. To overcome these defects, in this paper, the EMTDC simulation model to analysis the completely electrified railroad system with Scott transformer and AC auto-transformer is presented. Also, the correctness of EMTDC modeling is confirmed by the old basic concepts and we think that this EMTDC model has the future powerful capability for application of railroad system analysis.

• 한국철도학회논문집
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• 제5권4호
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• pp.253-259
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• 2002

This paper presents the first simulation model using EMTDC program to analyze the electrified train voltage distribution characteristics in ac auto-transformer fed railroads. In general, all of the electrified train supply system has the characteristics that the train supply line is a naturally non-symmetrical and unbalanced system. Also, it is needed to model the Scott transformer which invert the balanced 3-phase quantity into 2-phase. Therefore, the general simulation methodology using previous simplified equivalent circuit or RMS based program can't obtain the accurate results to reflect the real-time operation because these methodology is basically assumed on completely 3-phase balanced system. To overcome these defects, in this paper, the EMTDC simulation model to analysis the completely electrified railroad system with Scott transformer and AC auto-transformer is presented. Also, the correctness of EMTDC modeling is confirmed by the old basic concepts and we think that this EMTDC model has the future powerful capability for application of railroad system analysis.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2003년도 Proceedings of the international symposium on the fusion technology
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• pp.459-463
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• 2003

Waveform inversion requires extracting a reliable low frequency content of seismic data for estimating of the low wave number velocity model. The low frequency content of the seismic data is usually discarded or neglected because of the band-limited response of the source and the receivers. In this study, however small the spectral of the low frequency seismic data is, we assume that it is possible to extract a reliable phase information of the low frequency from the seismic data and use it in waveform inversion. To this end, we exploit the frequency domain finite element modeling and source-receiver reciprocity to calculate the $Frech\`{e}t$ derivative of the phase of the seismic data with respect to the earth model parameter such as velocity, and then apply a damped least squares method to invert the phase of the seismic data. Through numerical example, we will attempt to demonstrate the feasibility of our method in estimating the correct velocity model for prestack depth migration.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2003년도 Proceedings of the international symposium on the fusion technology
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• pp.402-409
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• 2003

Inversion of traveltime requires an efficient algorithm for computing the traveltime as well as its $Frech\hat{e}t$ derivative. We compute the traveltime of the head waves using the damped wave solution in the Laplace domain and then present a new algorithm for calculating the $Frech\hat{e}t$ derivative of the head wave traveltimes by exploiting the numerical structure of the finite element method, the modem sparse matrix technology, and SWEET algorithm developed recently. Then, we use a properly regularized steepest descent method to invert the traveltime of the Marmousi-2 model. Through our numerical tests, we will demonstrate that the refraction tomography with large aperture data can be used to construct the initial velocity model for the prestack depth migration.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집B
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• pp.692-697
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• 2000

In Particle Tracking Velocimetry, the analysis of double-exposed photographic plate can be carried out either by means of Young's fringe analysis or by a digital image processing technique. In this study, we used digital image processing to two images in one frame far analyzing in-cylinder flow fields, and compared PTV with PSV(Particle Streak Velocimetry). Additionally, this technique was verified by two different calibration method. One is interpolation by invert distance, the other is interpolation by area ratio. Finally, the results between two interpolation methods were similar in whole flow fields.