• Proceedings of the Korean Information Science Society Conference
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• 2005.07a
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• pp.895-897
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• 2005

이차원 평면에 직교다각형이 주어져 있을 때, 직교다각형 위에 45도 각도로 기울어진 면들로 구성된 지형 구조인 지붕(roof)을 정의할 수 있다. 본 논문에서는 직교다각형에 대한 지붕의 다양한 기하학적 성질을 살펴본다. 이것은 인공위성으로부터 얻은 건물의 평면도 이미지로부터 3차원 지붕구조를 획득하여 출력함으로써 사실감있는 영상을 제공하는 데 활용될 수 있다.

• Communications of Mathematical Education
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• v.15
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• pp.141-146
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• 2003

중학교 기하교육의 목적은 학생들의 수학적인 상황을 보는 기하학적인 직관과 논리적 추론능력의 향상이다. 그러나 이 두 가지 모두 만족스럽지 못한 실정이다. 본 고에서는 중학교 기하교육의 문제를 직관기하와 형식기하의 단절이라는 보고, 직관기하에서 증명의 학습요소를 미리 학습하여 직관기하와 형식기하를 연결하자는 대안을 제시한다. 이를 위해 7-나 교과서의 증명요소를 분석하고자 하였다. 관련문헌을 검토하여 7가지 증명의 학습요소를 선정한 후, 교과서를 분석하였다. 분석 결과, 기호화를 제외한 다른 증명의 학습요소는 매우 빈약한 것으로 나타났다. 직관기하 영역에 대한 교과서 구성이 개선될 필요가 있음을 알 수 있다.

• Journal of the Korean Society of Clothing and Textiles
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• v.19 no.5
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• pp.801-810
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• 1995

부직포의 기공크기에 대한 특성을 측정하기 위해 이미지 프로세싱을 이용하였다. 아라미드부직포와 그 부직포를 시뮬레이션한 부직포에 대해서 기공의 크기를 대표하는 평균 기공크기와 그 분포를 이미지 분석의 두가지 방법으로, 즉, 형태학적인 방법과 기하학적인 방법을 통해 측정해보았다. 아라미드 부직포, 시뮬레이견 부직포이건 상관 없이 부직포의 밀도가 증가함에 따라 기공의 크기특성, 즉 기공의 면적, 수력반경, 그리고 기공내의 최대 내접원의 반경은 감소하였다. 형태학적인 방법과 기하학적인 방법은 부직포의 종류에 상관없이 기공의 크기를 측정함에 있어서 유의한 차이가 없었다. 이는 부직포내의 섬유의 배열방향이 무작위이기 때문이었다. 실제의 아라미드 부직포와 시뮬레이션 부직포의 기공크기에 대한 특성은 서로 비슷한 양상을 보여주었다.

• Journal of Astronomy and Space Sciences
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• v.13 no.2
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• pp.181-197
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• 1996

Thc CCD earth image experiment(CEIE) is one of the main payload of the KITSAT-1. Since it was launched on Age. 11, 1992, the CEIE has taken more than 500 images on the earth surface world-wide so far. An image from the space is very different from a feature on the real Earth surface due to various radiometric and geometric distortions. Preprocessing to remove those distortions has to take place before the image data are processed and analyzed further for various applications. This paper summarizes the result of the operation of the CEIE and describes the procedure to perform preprocessing including radiometric and geometric correction.

• Journal for History of Mathematics
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• v.19 no.1
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• pp.79-90
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• 2006

The purpose of this paper is to derive the ratios of trigonometric special angles from Euclid's by constructing regular pentagon and decagon. The intention of this paper is started from recognizing that teaching of the special angles in secondary math classroom excessively depends on algebraic approaches rather geometric approaches which are the origin of the trigonometric ratios. In this paper the method of constructing regular pentagon and decagon is reviewed and the geometric relationship between this construction and trigonometric special angles is derived. Through such geometric approach the meaning of trigonometric special angles is analyzed from a geometric perspective and pedagogical ideas of teaching these trigonometric ratios is suggested using history of mathematics.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.4A
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• pp.325-328
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• 2011

In this paper, we present a new and simple derivation of the Craig representation for the two-dimensional (2-D) Gaussian Q-function in the viewpoint of geometry. The geometric derivation also leads to an alternative Craig form for the 2-D Gaussian Q-function. The derived Craig form is newly obtained from the geometry of two wedge-shaped regions generated by the rotation of Cartesian coordinates over two correlated Gaussian noises. The presented Craig form can play a important role in computing the probability represented by the 2-D Gaussian Q-function.

• Tunnel and Underground Space
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• v.12 no.1
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• pp.10-18
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• 2002

Rock joint system makes a heavy effect on the behavior of rock structures. The definition of a 3D rock joint system is very important in 2D or 3D numerical analysis for the prediction of the behavior of a discontinuous rock mass. To enhance the reality of a 3D definition of rock joint system, it is essential to estimate the unbiased statistics of basic geometric attributes of rock joints. In this study, we have proposed the statistical analysis and derived the related equations for an estimation of statistics of joint size and intensity. Geometry of rock joints in 3 dimensional space can be defined by the aggregate of location, size, orientation and intensity. The dimensional limit of survey method and its data makes 3D geometric attributes probabilistic. In the estimation of statistics of joint size, we have discussed the technique to correct the bias from a dimensional limit and derived the equation of 3D joint intensity by stereological approaches.

• Korean Journal of Remote Sensing
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• v.14 no.1
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• pp.69-82
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• 1998

SAR imagery can overcome the limitations of electro-optical sensor imagery and provide us Information which plays a supplementary role. But it is necessary to remove a variety of geometric errors in SAR imagery. An accurate geometric correction of SAR imagery is not easy task to achieve, though some techniques and theories are introduced. We also have difficulties such as transformation problem between 'International' ellipsoid in Radarsat system and 'Bessel' ellipsoid. Two widely used correction method, one is made by simulated image, and the other by collinearity equation, usually use DEM. In this study, the merits and demerits of geocoding methods respectively and the effective method for Korean terrain were found.

• Journal of the Korean GEO-environmental Society
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• v.9 no.5
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• pp.61-69
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• 2008

In general, it has been usually used the method that assess rock slope stability using stereographic projection method, limit equilibrium analysis, numerical analysis and slope stability evaluation table. Several methods for assessing the stability of rock slopes has been proposed on the basis of site investigation data. These method adopted different evaluation items and weighting factors by researchers, organization and nation. But the researches for each evaluation items were insufficient. So the effectiveness of rock slope stability evaluation items for geometrical configuration (slope height, slope direction and angle, dip and dip direction of major discontinuity, absolute value for the direction difference for slope and major discontinuities) and topographical characteristic (possibility of topographical water concentration, upper natural slope angle, slope configuration) using 315 failure and stable highway rock slope analysis data, AV (abnormal value) analysis and NMAV (normalized maximum abnormal value) analysis were evaluated.

• Archives of design research
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• v.18 no.2 s.60
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• pp.325-334
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• 2005

The purpose of this thesis is to explore the fundamental reasons and general circumstances of the introduction of geometric shape to the 20th century's design education. The modern design education was directly influenced by the German Kindergarten Movement and its educational ideal, so they began to employ geometric shapes in visual education. When Friedrich Frobel, a professional German child educator of the 19th century, invented the 'Spielgaben,' it soon became a popular educational tool. It was a turning point in the child educational system, from then they began to actively employ 'tools' in art education. The Spielgaben was created based on the geometric principle of a popular block game of the 19th century. On the other hand, a game program called 'Bechaftigungsmaterial' led early Modernists to adopt geometric shape in their works. Then, geometric shape were applied to a primary educational program designed by the Bauhaus that gave birth to the Modern design education in the 20th century. likewise, the substantial reasons why the principles of point/line/plain and geometric shapes had been taken in the 20th century design education can be explained through this historical background. This research is to investigate how Kindergarten Movement and Modern design education can be associated with each other, particularly in the light of geometric elements. Therefore, I first referred to the historic records in order to reveal their relation, and then analyzed the similarities and differences between the two activities. In result, I could explore the relationship between child educational tools and the 20th century's design education.