• Proceedings of the Korean Operations and Management Science Society Conference
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• 2002.05a
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• pp.248-252
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• 2002

Many sensors such as a structured grid pattern generator, a laser, and CCD camera to information have been used, but most of algorithms for a calibration are inefficient memory and experiment data are required. In this paper, the calibration algorithm of a structured grid pattern based on triang is introduced to calculate 3D information in the real world. The beams generated from str pattern generator established horizontally with the CCD camera are projected on the calibn CCD camera observes the intersection plane of a light and an object plane. The 3D infon calculated using observed and calibration data. This proposed method in this paper has advantages such as a memory saving and an experimental data since the 3D information are obtained simply triangulation method.

• Journal of Navigation and Port Research
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• v.38 no.1
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• pp.45-52
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• 2014

Fractal theory has been widely used to quantify the complexity of remotely sensed digital elevation models and images. Despite successful applications of fractals to a variety of fields including computer graphics, engineering and geosciences, the performance of fractal estimators depends highly on data sampling. In this paper, we propose an algorithm for computing the fractal dimension based on the triangular prism method and a new sampling method. The proposed sampling method combines existing two methods, that is, the geometric step method and the divisor step method to increase pixel utilization. In addition, while the existing estimation methods are based on $N{\times}M$ window, the proposed method expands to $N{\times}M$ window. The proposed method is applied to generated fractal DEM, Brodatz's image DB and real images taken in the campus to demonstrate its feasibility.

• Journal of Astronomy and Space Sciences
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• v.23 no.1
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• pp.71-90
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• 2006

This study is about , which constitutes Honcheonui(an armillary sphere) put of $\ulcorner$Uigijipseol$\lrcorner$ (Volume I) together with and -dealt with earlier than this subject. The study's construction on the text of is organized into 15 categories, including installation, observations, instructions for use, astronomical theories and formulas, etc. This study provides easy-to-understand illustrations of the figures shown in the original and contains detailed descriptions of the related calculation procedures. In the 'Instructions for Use of Honcheonui' discussed here, the readers are introduced to astronomical computation systems, mainly based on spherical trigonometry and proportional methods. The section also provides systematic and detailed reviews of astronomical theories and calculation procedures, allowing you to assess the level of astronomy knowledge at that time.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.12
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• pp.1883-1890
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• 2013

Location detection technology (LDT) is one of the core techniques for location based service (LBS) in wireless communication for improving resource management and quality of services. The location of a mobile station (MS) is estimated using the time of arrival (TOA) technique based on three circles with centers corresponding to coordinates of three base stations (BSs) and radius corresponding to distances between MS and BSs. For accurately estimating the location of MS, three circles should meet at a point for the trilateration method, but they generally do not meet a point because the radius is increased depending on the number of time delay for estimating the distance between MS and BS and the carrier frequency. The increased three circles intersect at six points and the three intersection points among them should be generally placed close to coordinate of the location for the specific MS. In this paper, we propose the shortest distance algorithm for TOA trilateration method, to select three interior intersection points from entire six points. The proposed approach selects three intersection points with the shortest distances between coordinates of MS and intersection points and determines the averaged coordinate of the selected three points, as the location of the specific MS. We demonstrate the performance of the proposed algorithm using a typical computer simulation example.

• The Journal of the Acoustical Society of Korea
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• v.22 no.8
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• pp.717-726
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• 2003

This paper presents the methods that design the Wavelet-based pitch detector for 2,4 kbps Harmonic-CELP Coder, and that achieve the effective waveform interpolation by decision window shape of the transition region, Waveform interpolation coder operates by encoding one pitch-period-sized segment, a prototype segment, of speech for each frame, generate the smooth waveform interpolation between the prototype segments for voiced frame, But, harmonic synthesis of the prototype waveforms between previous frame and current frame occur not only waveform errors but also discontinuity at frame boundary on that case of pitch halving or doubling, In addtion, in transition region since waveform interpolation coder synthesizes the excitation waveform by using overlap-add with triangularity window, therefore, Harmonic-CELP fail to model the instantaneous increasing speech and synthesis waveform linearly increases, First of all, in order to detect the precise pitch period, we use the hybrid 1st pitch detector, and increse the precision by using 2nd ACF-pitch detector, Next, in order to modify excitation window, we detect the onset, offset of frame by GCI, As the result, pitch doubling is removed and pitch error rate is decreased 5.4% in comparison with ACF, and is decreased 2,66% in comparison with wavelet detector, MOS test improve 0.13 at transition region.

• Journal of Engineering Education Research
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• v.11 no.2
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• pp.79-89
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• 2008

The purpose of this study is to research the women engineers' recognition with a triangulation method and make suggestions on desirable education in engineering. The research period is for about 4 months from December 15, 2007 to April 4, 2008. The objects of the research are two groups of female engineers at D college located in the metropolitan area - the first group had 187 women engineering majors, 3 women graduate students and 2 women professors in engineering department, and the second group had 5 women engineering majors who once stayed out of school temporarily, 4 women engineering graduates, and 5 graduates who are currently working. The second group is intently selected in order to look into the detailed factors that affect the recognition of women engineers. The methods of the research varied and included were surveys on the web, personal interviews, focus meetings, surveys by e-mail and telephone, etc. The results of the study show what the women engineers want in engineering education includes to have role models of women engineers who can cast a vision to them, get a leadership training especially for when they lead a group that has both man and woman members. It was also found that experincing a cooperative learning through diverse projects is essential to build basic character training and competency, and practical education is required for the major or becoming a full time worker.

• Journal of Educational Research in Mathematics
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• v.27 no.4
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• pp.833-855
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• 2017

This study aims to reinvestigate the reason for introducing radian as a new unit to express the size of angles, what is the meaning of radian measures to use arc lengths as angle measures, and why is the domain of trigonometric functions expanded to real numbers for expressing general angles. For this purpose, it was conducted historical, mathematical and applied mathematical analyzes in order to research at multidisciplinary analysis of the radian concept. As a result, the following were revealed. First, radian measure is intrinsic essence in angle measure. The radian is itself, and theoretical absolute unit. The radian makes trigonometric functions as real functions. Second, radians should be aware of invariance through covariance of ratios and proportions in concentric circles. The orthogonality between cosine and sine gives a crucial inevitability to the radian. It should be aware that radian is the simplest standards for measuring the length of arcs by the length of radius. It can find the connection with sexadecimal method using the division strategy. Third, I revealed the necessity by distinction between angle and angle measure. It needs justification for omission of radians and multiplication relationship strategy between arc and radius. The didactical suggestions derived by these can reveal the usefulness and value of the radian concept and can contribute to the substantive teaching of radian measure.

• Korean Journal of Materials Research
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• v.7 no.11
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• pp.1007-1011
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• 1997

영활화혁발전소 보일러헤다 재질인 1Cr0.5Mo강의 파형에 따른 저주기 피로특성을 규명하고자 상온(298K) 및 고온(177K)의 삼각파와 사인파형 저주기 피로시험을 수행하였고 소성에너지법을 이용하여 파형에 따른 소성변형에너지와 피로수명과의 +관계를 분석하였다. 저주기 피로시 재료내부의 소성변형에너지를 히스테리시스루프의 면적으로 계산하여 구하였으며 이를통해 저주기 피로수명을 예측하였고 Coffin-Manson법 및 변형률분할법을 이용한 저주기 피로수명 결과와 서로 잘 일치하였다. 또한 상온 및 고온에서 피로반복수의 증가와 함께 재료가 반봅연화됨을 알 수 있었다.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.396-401
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• 2006

하천의 2차원 흐름, 유사이동 그리고, 오염 확산의 정도를 알아보기 위해 유한 요소법을 이용한 해석 방법이 널리 사용되고 있다. 유한 요소법을 이용할 때 유한 요소망 생성이 필수적이며, 해석 결과에 크게 영향을 주는 변수로 작용하게 된다. 본 연구에서는 복잡한 경계를 가진 하천의 유한 요소망 생성을 위해 대표적인 비구조적 요소망 생성 기법인 Delaunay 삼각화 기법과 흐름의 특성을 잘 나타낼 수 있도록 Transfinite 보간법을 이용한 구조적 요소망 생성 기법을 구현하였다. 그리고, 본 연구에 의해 생성된 유한 요소망의 형질 평가를 통해서 해석 결과에 대한 신뢰성을 높였으며, 요소망 생성 GUI 프로그램을 통하여 요소망에 대한 1차식의 요소와 2차식의 요소간의 변환, 되돌리기, 다시 실행 등의 기능을 지원하여 사용의 편리성을 추가하였다.

• 한국정보통신설비학회:학술대회논문집
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• 2006.08a
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• pp.185-188
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• 2006

본 논문에서는 Moment 법을 이용한 안테나 해석 프로그램에 대해 다룬다. Delaunay 삼각화 알고리즘에 근거하여 pre-processor를 구현한다. Moment법을 이용하여 main-processor를 구현한다. S-parameter를 주파수 영역과 Smith Chart에 표시하고, 방사패턴을 다양한 각도에서 확인 할 수 있도록 post-processor를 구현한다. 해석 결과의 신뢰성을 위해 20GHz 에서 동작하는 고 이득 및 고지향성을 갖는 마이크로스트립 패치 안테나 어레이를 설계하고 이를 제작 및 측정한다. 측정결과와 상용 툴의 결과와 구현한 프로그램의 결과를 비교 및 분석한다.