• Proceedings of the Acoustical Society of Korea Conference
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• 1996.06a
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• pp.18-21
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• 1996

예인형 선배열 소나에서 기존의 선배열 빔형성 기법을 적용하면 예인함 기동시 선배열 형상 변형에 의해 심각한 성능 저하 현상이 나타난다. 이러한 문제 해결을 위해 센서배열 변형을 고려한 견실한 빔형성 기법은 선배열 형상 추정을 위해 칼만필터를 이용한 형상 추정기법을 이용하고, 변형보상 빔형성을 위해 선배열 세그먼트 기울기 추정값을 이용하는 변형보상 빔형성 알고리즘을 제안하였다. 제안된 기법을 기존의 빔형성 기법을 적용하여 시뮬레이션에 의해 제안된 기법의 보상성능을 입증 하였다.

• The Journal of Korean Philosophical History
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• no.23
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• pp.67-97
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• 2008

In this paper, I found the leadership core-value of the Sunbai(선배) a man of refined taste. I studied twelve Sunbai considered as a man of refined taste in this research. I focused on the aspect showing common worth among their various abilities and cultural contributions, a point of view of classifying them into one form called Sunbai a man of refined taste. As the core value is the basis of supporting the individual identity, so the leadership core-value is the source and philosophical base of displaying the leadership. Our Sunbai combining character and knowledge show common structure in their personal growth and showing the leadership. It is that they embodied the stage of cultivating themselves(修身, Self), considering the relation with others(齊家, Relation), leading the organization(治國, Team), and making efforts for and having influence on the community(平天下, Community) throughout their own life. I examined how to display the leadership in the four fields on a case by case basis and then constructed the leadership model of the Sunbai a man of refined taste by synthesizing them. As a result, I considered their leadership core-value as the intercommunication and named it 'Leadership of Muaesabang(無碍四方)'. Also, I confirmed that it is still very valuable in these days of aiming at the open society and the harmony of the diverse civilization.

• Proceedings of the Acoustical Society of Korea Conference
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• 1998.06c
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• pp.469-472
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• 1998

수중에서 발생된 기포들의 상화작용에 의한 방출주파수의 변화를 알아보기 위해 선배열 기포에 대해 이론적으로 연구하였다. 기포들의 결합진동에 의한 방출주파수는 가능한 가장 저주파수의 음파가 발생됨을 설명하였으며, 일부의 기포가 음원역할을 하는 실제적인 선배열 기포의 경우는 방출주파수가 기포의 총 개수보다는 음원기포의 개수와 기포간 거리에 좌우됨을 밝혔다. 이러한 이론결과는 참고문헌[6]의 실험결과에 비교적 잘 일치하였다. 이것은 기포간의 결합진동은 기포들의 초기 발생조건에 따라 이론적으로 다르게 다루어야 함을 의미한다.

• Journal of the Korea Institute of Military Science and Technology
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• v.9 no.2 s.25
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• pp.20-25
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• 2006

Low frequency towed line array with high array gain and beam resolution is a long range surveillance sensor for anti-submarine warfare. The beam characteristics is however deteriorated due to the distorted line array sensor caused by low towing speed, wind, current, and towing ship maneuvering. An adaptive beamforming method is utilized in this paper to enhance the distorted line array beam performance by estimating and compensating the nonlinear array shape. A polynomial curve fitting in the least square sense is used to estimate the array shape iteratively with the distributed heading sensors data along the array. Real time array shape estimation and nonlinear array beam calculation is applied to a very long towed line array sensor system and the beam performance is evaluated and compared to the linear beamformer for the simulation and sea trial data.

• The Korean Publising Journal, Monthly
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• s.228
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• pp.7-7
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• 1998

한 분야에서 일가를 이룬 원로들이 자신들의 삶을 되돌아보는 글을 펴내 잔잔한 감동을 일으키고 있다. 이러한 회고록들은 연약한 육체와 황폐한 정신으로 몸살을 앓고 있는 현대인에게 인생선배가 달여주는 '보약'이다.

• The Journal of the Acoustical Society of Korea
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• v.25 no.7
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• pp.346-355
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• 2006

Acoustic data from a shallow water experiment in the East Sea of Korea (MAPLE IV) is Processed to investigate the Performance of matched-field geo-acoustic inversion and source localization. The receiver array consists of two legs as in an L-shape. one vertical and the other horizontal lying on the seabed. Narrowband multi-tone CW source was towed along a slightly inclined bathymetry track. The matched-field geo-acoustic inversion includes comparisons between three processing techniques. all based on the Bartlett processor as; (1) the coherent processing of the data from the full array, (2) the incoherent Product of each output from both the horizontal and vertical arrays, and (3) the cross correlation between the horizontal and vertical arrays. as well as processing each array leg separately. To verify the inversion results. matched-field source localization for low level source signal components were performed using the same Processors used at the inversion stage.

• Digital Contents
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• no.7 s.146
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• pp.14-15
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• 2005

김선배 전 현대정보기술 대표이사가 지난달 1일자로 한국정보통신수출진흥센터(ICA) 제2대 원장에 취임했다. 김 신임 원장은“앞으로 ICA가 정보통신분야의 국제협력에 중추적인 역할을 할 수 있도록 노력하겠다”고 말했다. 김 신임 원장은 금융ㆍ건설ㆍ정보통신 등 다양한 분야에서 전문성을 쌓아왔고 현대정보기술 대표이사와 한국소프트웨어산업협회장 등을 역임했다.

• The Journal of the Acoustical Society of Korea
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• v.33 no.6
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• pp.383-391
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• 2014

In order to detect underwater acoustic signals, various SONAR array types have been developed, including towed line array SONAR system (TASS). However, the TASS suffers from performance degradation which is caused by aperture deformation during a turn, because the TASS have a long-aperture array. A parabolic array model for turning TASS have been developed to solve the degradation problem occurred during a turn. In this paper, adaptive beamforming system is developed using the parabolic TASS model to cancel interference signals. The developed beamforming system is based on generalized sidelobe canceller (GSC) structure and self-tuning adaptive algorithm.

• 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.

• The Journal of the Acoustical Society of Korea
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• v.39 no.4
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• pp.255-262
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• 2020

In modern passive sonar systems, a towed array sensor is used to minimize the effects of own ship noise and to get a higher SNR. The thin and long towed array sensor can be guided in a non-linear form according to the maneuvering of tow-ship. If this change of the array shape is not considered, the performance of beamformer may deteriorate. In order to properly beamform the elements in the array, an accurate estimate of the array shape is required. Various techniques exist for estimating the shape of the linear array. In the case of a method using a heading sensor, the estimation performance may be degraded due to the effect of heading sensor noise. As means of removing this potential error, weighted polynomial fitting technique for estimating array shape is developed here. In order to evaluate the performance of proposed method, we conducted computer simulation. From the experiments, it was confirmed that the proposed method is more robust to noise than the conventional method.