• ETRI Journal
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• 제32권6호
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• pp.837-842
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• 2010

This paper proposes robust source localization methods for estimating the azimuth angle, elevation angle, velocity, and range using a low-complexity planar antenna array in impulsive non-Gaussian noise environments. The proposed robust source localization methods for wireless communication applications are based on nonlinear M-estimation provided from Huber and Hampel. Simulation results show the robustness performance of the proposed robust methods in impulsive non-Gaussian noise.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2007년도 공동학술대회 논문집
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• pp.279-284
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• 2007

The cultural noise sources in magnetotellurics were localized using the source localization method. Conventional beamforming techniques are not applicable for electromagnetic source localization. In this study, the matched field processing and genetic algorithm are used to localize an electromagnetic source and estimate the polarization direction. The source localization using MT field data shows the characteristics of estimated source distribution related to the strength of cultural noise.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.1075-1075
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• 2006

• 대한조선학회논문집
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• 제48권2호
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• pp.121-127
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• 2011

As considerable interests in noise emission from a ship have been increased, the need for localization of noise sources of the marine propeller generating cavitation and singing noise is looming large. In many practical cases, cavitation and singing noise occur on a particular position of the certain blade of the propeller. It is so important to know the position of noise source correctly in order to eliminate or suppress unwanted noise. In this study, we develop "noise source localization technology" using TDOA method. Experimental measurements carried out at the circulating water channel and towing tank show that noise source can be clearly identified and localized using TDOA method.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 춘계학술대회논문집
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• pp.489-494
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• 2003

Vibration localization characteristics of open loop repeated structures with mistuning are investigated in this paper. Mistuning of a periodic structure often creates significant non-uniformity in vibration responses. As a result of the localization, critical fatigue problems often occur in repeated structures. Therefore, it is of great importance to predict the vibration response of the mistuned repeated structures accurately. In this paper, a simplified model for the open-loop repeated structure is introduced and dimensionless parameters which influence the localization characteristics are identified. The effects of the parameters on the localization characteristics are investigated through numerical study.

• Investigative Magnetic Resonance Imaging
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• 제7권2호
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• pp.108-115
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• 2003

목적 : MRI를 촬영하면서 동시에 측정한 뇌전도 신호에 가장 크게 영향을 미치는 것은 경사자계 유발 잡음이다. MRI와 동시에 측정한 뇌전도 신호에서 전류원 국지화를 수행할 때, 경사자계 유발 잡음이 미치는 영향을 분석하고자 한다. 대상 및 방법 : 사람의 머리와 유사하게 만든 뇌전도 팬텀과 MR compatible 뇌전도 측정시스템, 그리고 3.0 Tesla MRI 시스템을 실험에 사용하였다. 3.0 Tesla MRI 시스템 안에 전류원이 설치되어 있는 뇌전도 팬텀을 놓고, EPI 촬영을 하는 동안 뇌전도 신호를 측정하였다. 경사자계의 세기와 전류원의 위치를 조절하면서 뇌전도 신호 측정을 하였고, 측정된 뇌전도 신호에 대하여 전류원 국지화를 수행할 때 나타나는 국지화 오차를 평가하였다. 결과 : 경사자계 유발잡음에 의한 국지화 오차는 경사자계의 세기와 전류원의 위치에 따라 변화하는 것을 관찰하였다. 또한 경사자계 유발잡음이 Gaussian 잡음보다 전류원 국지화에 미치는 영향이 큰 것을 관찰하였으며, 경사자계 유발 잡음의 전력이 뇌전도 신호 전력의 $10\%$ 이하일 때는 전류원 국지화에 미치는 영향이 미미함을 관찰하였다. 결론 : 경사자계 유발 잡음 전력을 뇌전도 신호 전력의 $10\%$ 이하로 줄인다면 MRI를 하면서 동시에 측정한 뇌전도 신호로도 전류원 국지화를 할 수 있음을 알 수 있었다.

• Smart Structures and Systems
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• 제22권5호
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• pp.621-630
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• 2018

Boundary effect and the noise robustness are the two crucial aspects which affect the effectiveness of the damage localization based on the mode shape measurements. To overcome the boundary effect problem and enhance the noise robustness in damage detection, a simple damage localization method is proposed based on the Singular Value Decomposition (SVD) for the mode shape of composite plates. In the proposed method, the boundary effect problem is addressed by the decomposition and reconstruction of mode shape, and the noise robustness in enhanced by the noise filtering during the decomposition and reconstruction process. Numerical validations are performed on plate-like structures for various damage and boundary scenarios. Validations show that the proposed method is accurate and effective in the damage detection for the two-dimensional structures.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 추계학술대회논문집
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• pp.704-709
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• 2003

Vibration localization characteristics of repeated mistuned structures are investigated by two ways. The mistuning often creates significant response discrepancies among subcomponents of the repeated structures. As a result of the discrepancies, critical fatigue problems often occur in repeated structures. Therefore, it is of great importance to predict the vibration response of the mistuned repeated structures accurately. In this paper, a simplified model is employed and dimensionless parameters that influence the localization characteristics are first identified. Through the parameter study, the two localization phenomena are investigated and compared.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1997년도 춘계학술대회논문집; 경주코오롱호텔; 22-23 May 1997
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• pp.211-216
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• 1997

The mode localization phenomenon in non-periodic multispan beam is theoretically investigated. When localization occurs, the free vibration amplitude of a normal mode becomes confined to a local region of the structure. It is well known that the weakly coupled periodic structures are sensitive to certain types of periodicity-breaking disorder, resulting in the mode localization. The results of this study indicate that the mode localization occurs also in nonperiodic structures and the degrees of mode localization of some modes are very sensitive to system parameters. Free vibration analysis of simply supported two-span beams of arbitrary span lengths is performed. Degrees of mode localization and their sensitivities to system parameters are appraised by considering the characteristic graph and the structural line defined in this study first.

• 제어로봇시스템학회논문지
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• 제16권5호
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• pp.415-419
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• 2010

A variety of methods for sound source localization have been developed and applied to several applications such as noise detection system, surveillance system, teleconference system, robot auditory system and so on. In the previous work, we proposed the sound source localization using the spatially mapped GCC functions based on TDOA for robot auditory system. Performance of the proposed one for the noise effect and estimation resolution was verified with the real environmental experiment under the single source assumption. However, since multi-talker case is general in human-robot interaction, multiple source localization approaches are necessary. In this paper, the proposed localization method under the single source assumption is modified to be suitable for multiple source localization. When there are two sources which are correlated, the spatially mapped GCC function for localization has three peaks at the real source locations and imaginary source location. However if two sources are uncorrelated, that has only two peaks at the real source positions. Using these characteristics, we modify the proposed localization method for the multiple source cases. Experiments with human speeches in the real environment are carried out to evaluate the performance of the proposed method for multiple source localization. In the experiments, mean value of estimation error is about $1.4^{\circ}$ and percentage of multiple source localization is about 62% on average.