• ETRI Journal
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• v.27 no.3
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• pp.280-288
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• 2005

This paper presents an efficient algorithm for using the two-axis magnetic compass in portable devices. The general magnetic compass module consists of a three-axis magnetic compass and a two-axis inclinometer to calculate tilt-compensated azimuth information. In this paper, the tilt error is compensated using just a two-axis magnetic compass and two-axis accelerometer. The third-axis data of the magnetic compass is estimated using coordinate information that includes the extended dip angle and tilt information. The extended dip angle is estimated during the normalization process. This algorithm can be used to provide the tilt-compensated heading information to small portable devices such as navigation systems, PDAs, cell phones, and so on.

• Journal of the Society of Naval Architects of Korea
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• v.42 no.3
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• pp.249-258
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• 2005

Recently, the vibration reduction at a local structure such as compass deck has been continuously requested by ship owner and shipbuilder. Because crews are afflicted with vibration, severe vibration problems even bring about a damage of structure. This study conducted to get an optimized stiffener size of compass deck to reduce the vibration level and decrease the weight of structure in ship. NASTRAN external call type optimization software (OptShip) which makes use of NASTRAN as a solver is used as an optimization tool. The results indicate that the optimum design is promising for real applications.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2006.06b
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• pp.77-85
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• 2006

The last target of this study is to develop ship's Digital Compass that can be substitute with conventional ship's Magnetic Compass. At first, new Digital Compass system was developed with three-axis high accuracy Flux-gate sensors and small sized step motor. Then after, new deviation correction theory without ship's swinging procedures was proposed to provide automatic deviation analysis, correction and renewal. Throughout the performance evaluation tests on the training ship 'SAE-NU-RI', the effectiveness of developed Digital Compass and proposed deviation correction theory are verified.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.08a
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• pp.29-36
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• 2004

The paper describes recent experimental results on the development of Digital Magnetic Compass (DMC), which can provide smart automatic correction functions to the magnetic interferences. The design methodology of magnetic sensing circuit with ring-core fluxgate sensor is represented. The performance results of the sensing circuits are discussed with error analysis by polynomial regressions. As test results, the sensing circuit filtered only the second harmonic signal that is proportional to the direction of earth's magnetic field, and it leads to the obtainment of bearing information. In addition, the total residual errors of DMC can be analyzed by the adoption of polynomial regressions. It shown that the possibility of high precise DMC, in the future.

• Journal of Elementary Mathematics Education in Korea
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• v.20 no.4
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• pp.541-561
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• 2016

In this paper we discussed about the contents which were related with geometric construction in elementary school. We examined how the compass has been used in the curriculum and textbooks. Thus we found several features. And we inspected the ideas and sequences about geometric construction in Waldorf mathematics education. Finally, we suggested how to change the contents to make the relationships between elementary school and middle school better.

• Proceedings of the KIEE Conference
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• 2008.04a
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• pp.69-70
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• 2008

통합 항법 시스템 구현시 각 센서 측정치의 동기를 맞추어 칼만 필터의 상태변호를 갱신을 해야 하지만, 상용 센서를 사용 할 경우 각 센서 측정치의 출력 동기를 맞추기 어려울 뿐만 아니라, 통합 항법 컴퓨터까지의 전송 과정에서 지연시간이 생기므로 특히 고기동 항체에서는 센서측정치 비동기로 인하여 항법 성능이 저하가 커진다. 본 논문에서는 GPS/INS/Magnetic compass 통합 항번 시스템의 동기 방법을 제안한다. 이 방법은 센서 하드웨어의 변경이 필요 없이 동기를 맞출 수 있어 상용 센서를 사용하여 항법 시스템을 개발할 때 유용하게 사용 할 수 있다. 이 방법의 성능을 검증하기 위해 고속 항체의 시나리오 구성하고 모의실험을 통해 유효성을 확인 할 수 있었다.

• Proceedings of the Korean Institute of Landscape Architecture Conference
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• 2007.10b
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• pp.127-132
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• 2007

Geomancy(風水, Fengshui in Chinese) is a geographic idea of the Orient that studies a piece of land(a site) to pursue the healthier and more comfortable life for people seeking a harmony with nature, and also, a practical science. Among the theoretical systems of the traditional geomancy handed down by the scriptures, the compass school(理氣論) makes researches into mountains, winds, the currents and amount of water circulation by using luo-pan(羅盤) for finding spot(穴), and it has been considered that it is the objective and logical analysis system of natural environment of selecting a good site by dividing the vitality of the ground into 12 levels of natural circulation principles and judging its direction by means of 88-direction method. In this context, researcher optimized the logic of 88-direction method by the 12-circulation system(胞胎法) of the compass school on the basis of directional theory, then after, using GIS analytical tool, researcher performed comparative analysis between the results from land suitability analysis of the subject site and the resulting value of the directional method in geomancy. The results therefrom indicated that more flexible directions and site could be chosen by applying 88-direction method. For the future research, it is required to apply wider variety of variables to the field study and more careful review of the case study with a focus on the 88-directiont method.

• Proceedings of KOSOMES biannual meeting
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• 2006.11a
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• pp.137-141
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• 2006

To consider the practical use of a ship's Digital Compass in earth's magnetic field high accurate Deviation and 얘 nation are required to obtain ship's true bearing. Variation can be obtain with World Magnetic Model (WMM) using the Earth's spherical harmonic model of the main field and of the secular variation at any location around the earth. Deviation can be obtain with deviation analysis and synthesis method based on the Poisson equations. As results of deviation and variation corrections to the Digital Compass, high accurate true bearing is obtained. This experiments are carried out during in the navigation of training ship 'SAE-NU-RI'.

• Journal of Navigation and Port Research
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• v.36 no.9
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• pp.699-706
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• 2012

This paper describes Declination interpolation method in the application of Digital Magnetic Compass(DMC) with small capacity memory for relatively low-priced system. The purpose of this study is to find accurate declination values using Declination Lookup Table(DLT) and Secular Variation Table(SVT) with the Bilinear interpolation method having four points data only. World Magnetic Model with Gauss coefficients produced by NOAA is used in the calculation of DLT and SVT at desired years. To verify the applicability of the proposed method, the simulation tests and the error analysis are carried out in this work. As results from tests, the interpolation error is within 0.01 degree that is much enough to implement high accurate DMC comparing with commercial DMCs on the market. In summary, the declination interpolation method, proposed in this study, can be useful in the application of DMC.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1429-1432
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• 2005

This work is towards the development of a low-cost, small-sized inertial navigation system(INS) which consists of 3 accelerometers, 3 semiconductor gyros and a magnetic compass sensor. This paper explains in detail the structure of the developed system and proposes a 3 dimensional attitude estimation algorithm with Indirect Kalman Filter. The experiments are performed with the developed system attached to a 6 DOF robot for showing the effectiveness of the algorithm.