• Proceedings of the Acoustical Society of Korea Conference
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• autumn
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• pp.85-88
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• 2000

가늘고 긴 선배열을 해상에서 운용할 때 비선형 형상이 유도되므로 음원에 대한 정확한 탐지를 위하여 배열형상 추정이 필요하다. 방위센서를 이용한 배열형상 추정을 위하여 배열의 천 정도가 적은 경우에만 적용 가능한 다항 근사화 방법의 제한점을 극복하기 위하여 반복법을 제안하고, 수치 시뮬레이션을 통하여 반복회수에 따른 배열형상 추정결과를 분석하였다

• Convergence Security Journal
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• v.6 no.3
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• pp.37-47
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• 2006

In this research, We connect the terrestrial magnetism sensor of the Philips to a bluetooth communication system and measured 360 degree of the azimuth change the angle with an incline of 5 degrees to an order direction. The value of the azimuth to be measured sent to the Bluetooth communication system and analyzed the measuring value in the 100m as moved. Using the bluetooth, we could send the measuring value of the azimuth without the bearing error in the plain without an electric wave obstacle within a distance in straight line 100M. We got the value of the azimuth have 98% reliability to maintain at a level with the terrestrial magnetism sensor. Based on this research. We send the measuring value of the azimuth which the accuracy is improved to a mobile intelligent robot moving a land inclined equipped with this system and can track the azimuth of it.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.34 no.5
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• pp.471-478
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• 2016

This paper proposes the results of analysis of correlation between satellite geometry elements for an effective use of satellite images. To achieve accurate positional information, stereo images have normal range of convergence and BIE (BIsector Elevation) angles which are greatly influenced by azimuth and elevation angle of individual image. In this paper, the variations of convergence and BIE angles are estimated according to azimuth angle differences between two images and each elevation angle. The analysis provided strong support for predicting stereo geometry without complex analysis of epiploar geometry or mathematics. The experiment results showed that more than 150°, 130°, and 100° azimuth angle differences need to be constructed when elevation angle of two images is 50°, 60°, and 70°, respectively, in order to make the convergence and BIE angle within normal range. The results are expected to be fully used for various application using stereo images.

• The Journal of the Acoustical Society of Korea
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• v.35 no.5
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• pp.395-402
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• 2016

In this paper, a wideband adaptive beamforming approach for an acoustic vector sensor linear array is presented. It is a very important issue to estimate the stable covariance matrix for adaptive beamforming. In the conventional wideband adaptive beamforming based on coherent signal-subspace (CSS) processing, the error of bearing estimates is resulted from the focusing matrix estimation and the large number of data snapshot is necessary. To alleviate the estimation error and snapshot deficiency in estimating covariance matrix, the steered covariance matrix method in the pressure sensor is extended to the vector sensor array, and the subarray technique is incorporated. By this technique, more accurate azimuth estimates and a stable covariance matrix can be obtained with a small number of data snapshot. Through simulation, the azimuth estimation performance of the proposed beamforming method and a wideband adaptive beamforming based on CSS processing are assessed.

• Proceedings of the Acoustical Society of Korea Conference
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• 1984.12a
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• pp.107-112
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• 1984

수동 Wave-front curvature ranging 방법의 통계적성능에 대한 일반적 결과가 유도된다. 센서들의 비선형 및 부동간격 센서들의 운동효과로 인한 표적거리의 편의(bias) 및 편차9variance)가 센서간의 운동이 상관관계를 가지고 있을 때 유도된다. 이 논문은 센서운동이 정규분포(normal distribution)를 가지며 평균이 0, 같은 편차 및 투시할 수 있는 higher moment를 가지고 있다고 가정한다. 유도된 일반적 결과를 이용하여 거리편의 및 편차는 표적거리, 방위, 센서운동의 상관계수 및 방향각(heading)표준편차 변화에 대해 그림으로 나타나 있다. 표적거리가 센서간격보다 아주 큰 경우 센서간격이 감소할수록, 표적거리가 증가할수록, 거리편의 및 편차는 증가한다. 상관계수가 증가할수록 거리편의는 직선적으로 감소하며, 거리편차는 센서 방향각 오차가 클 때 최소가 되는 상관계수가 존재하며 이는 표적거리, 방위 및 센서간격의 복합함수이다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1995.04a
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• pp.117-133
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• 1995

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.168-172
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• 2005

An autopilot system of a ship is very important for a safe and convenient navigation, which is realized with getting an azimuth data from a gyrocompass, a magnetic compass and a GPS(Global Positioning System) compass. Magnetic compass an azimuth error is generated by a vessel magnetism material such as steels. The magnetic pole is detected by the magnetic field sensor, it does not coincide with the true north, therefore, the detected azimuth data can not but accompany error. In this paper, in order to detect the minimum change of azimuth data which generates errors of azimuth information, a search algorithm using the Kalman Filtering method is utilized. The digital electronic compass is designed with the integration algorithm using the merits of an earth's magnetic field sensor and a GPS receiver.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.6
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• pp.137-141
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• 2022

The method of estimating the azimuth by measuring the geomagnetism has been used for a very long time. However, there are many cases where an error occurs in the estimated azimuth due to disturbances in the earth's magnetic field due to metal structures inside and outside the room. Although many studies have been conducted to correct this, there is a limit to reducing the error. In this paper, we propose a method of estimating the azimuth by applying the measured geomagnetic sensor data to the neural network of the LSTM structure. Data preprocessing is very important for learning a neural network. In this paper, data is collected using the built-in acceleration sensor, gyro sensor, and geomagnetic sensor in the smartphone, and the geomagnetic sensor data is uniformly sampled using EKF. As a result, an average azimuth estimation error of 0.9 degrees was obtained using four hidden layers.

• Journal of the KSME
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• v.34 no.7
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• pp.546-557
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• 1994

원격 조정식 비익체(이하 RPV : Remoteloted Vehicle)의 안정성을 향상시키고 조정을 간략화하기 위하여 사용되고있는 관성센서에 관해서 알아본다. 관성센서의 기본 원리는 뉴톤의 운동 제3 법칙인 관성의 법칙이고, 특징은 외부 측정기준을 필요로 하지 않은 점에 있으므로, 관성센서를 탐재한 RPV는 공중에서 운동 상태를 외부의 정보 없이 검토할 수 있다. 실제적으로 기계용으로 실용화되고 있는 센서는 관성항법장치(INS:Inertial Navigation System)라고 불리워지는 매우 고급자립형 장치로부터 자이로 컴파스로 불리워지는 방위 자이로와 자기 방위 센서를 조합한 방법까지 여러 가지가 있지만, 여기에서는 산업용 소형 RPV의 크기, 가격 및 입수성에서 이용이 가능하다고 생각되는 센서를 중심으로 원리, 종류 및 응용예를 설명한다.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.1
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• pp.114-120
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• 2013

Recently, navigation systems based on wireless communication have been applied to the internal structures such as building or ship. If a stable azimuth information is obtained, these systems can effectively guide the direction of the user's progress through the information and then can improve the performance of guidance. Since conventional method which has acquired an azimuth information using geomagnetic and acceleration sensor(azimuth sensor hereafter) is sensitive to the effects of the magnetic field, it has unstable error range according to the surrounding environment. In order to improve these problems, this paper presents a new relative azimuth estimation algorithm using the displacement of a mobile node and its rotation angle based on Wireless communication. For the performance assessment of the proposed algorithm, experiments using rotating arm are performed and the results are confirmed that the proposed system can estimate the relative azimuth without using additional sensors.