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1

An iterative approach to sound source localization based on spherical beamforming

Szwajcowski Adam, Makuch Teresa, Celniak Weronika

Vibrations in Physical Systems

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2023

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Vol. 34, nr 2

art. no. 2023216

EN

Precise and efficient localization of sound sources is essential in many applications. Traditionally, methods that use beamforming tend to scan the entire space with fixed level of precision. Although effective, this approach is inefficient when searching for a single source. In this paper we propose an iterative algorithm for localizing a single sound source utilizing signals from a 4th order ambisonic microphone array. Two beamformers were implemented: one based on signals in A-format, incorporating delay-and-sum method, commonly used for sound source localization, and the second one based on B-format, operating in the spherical harmonic domain. By utilizing an iterative algorithm, we have significantly decreased the number of points to be evaluated to localize the sound source. For the delay-and-sum beamformer, the best outcome was obtained by using all 32 channels in every iteration. For the spherical-harmonics-based beamformer, the best strategy was to use first-order harmonics in the initial iteration and fourth-order harmonics in subsequent iterations.

2

Optymalna lokalizacja źródeł generacji rozproszonej w terenowej sieci średniego napięcia

Marzecki J.

Przegląd Elektrotechniczny

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2018

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R. 94, nr 3

151--154

PL

W artykule omawia się metodę lokalizacji źródeł generacji rozproszonej w terenowej sieci SN. Przedstawia się rolę generacji rozproszonej w regulacji napięć w sieci terenowej oraz model sieci SN przydatny w analizach technicznych. Omawia się kryteria optymalnej lokalizacji źródeł rozproszonych w sieci dystrybucyjnej oraz dokonuje się ich analizy. Przeprowadza się analizę dopuszczalnych wariantów lokalizacji źródeł rozproszonych w sieci terenowej SN przy zastosowaniu trzech kryteriów.

EN

The paper discusses a method of location of distributed generation sources in a MV rural network. The role of distributed generation in the voltage regulation in the rural network and a model of the MV network, useful to technical analysis, are presented. The criteria for the optimal location of distributed generation sources in the distribution network are discussed and their analysis is made. The analysis of permitted location variations of distributed generation sources in the MV rural network is made with the use of three criteria.

3

Time reversal seismic source imaging using peak average power ratio (PAPR) parameter

Franczyk A., Leśniak A., Gwiżdż D.

Acta Geophysica

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2017

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Vol. 65, no. 2

299--308

EN

The time reversal method has become a standard technique for the location of seismic sources. It has been used both for acoustic and elastic numerical modelling and for 2D and 3D propagation models. Although there are many studies concerning its application to point sources, little so far has been done to generalise the time reversal method to the study of sequences of seismic events. The need to describe such processes better motivates the analysis presented in this paper. The synthetic time reversal imaging experiments presented in this work were conducted for sources with the same origin time as well as for the sources with a slight delay in origin time. For efficient visualisation of the seismic wave propagation and interference, a new coefficient—peak average power ratio—was introduced. The paper also presents a comparison of visualisation based on the proposed coefficient against a commonly used visualisation based on a maximum value.

4

Heating source localization in a reduced time

Beddiaf S., Autrique L., Perez L., Jolly J. C.

International Journal of Applied Mathematics and Computer Science

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2016

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Vol. 26, no. 3

623--640

EN

Inverse three-dimensional heat conduction problems devoted to heating source localization are ill posed. Identification can be performed using an iterative regularization method based on the conjugate gradient algorithm. Such a method is usually implemented off-line, taking into account observations (temperature measurements, for example). However, in a practical context, if the source has to be located as fast as possible (e.g., for diagnosis), the observation horizon has to be reduced. To this end, several configurations are detailed and effects of noisy observations are investigated.

5

Passive sound source localization system

Baszun J.

Zeszyty Naukowe Politechniki Białostockiej. Informatyka

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2011

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Z. 7

5-16

EN

Acoustic source localization system for speech signals based on five microphone array was developed. Three dimensional position computation is based on time delay estimation between pairs of microphones. The psyhoacoustically motivated voice activity detector was used to robustly determine activity of speaker in presence of background noise. The detector was based on modulation properties of human speech. Good performance was obtain by selecting frames with speech and nulling frequency bands without speech components. As the result more precisely computation of the time delay was possible. Real experiments shown good immunity of the proposed algorithm to noise and reverberation.

PL

Opracowano metodę lokalizacji akustycznych źródeł dźwięku zorientowaną na sygnału mowy. System zbudowano w oparciu o macierz pięciu mikrofonów. Obliczenia pozycji źródła w trzech wymiarach dokonano na podstawie estymacji różnicy czasu przybycia dla par mikrofonów. Zastosowany psychoakustycznie motywowany detektor mowy umożliwia ocenę aktywności mówcy w obecności zakłóceń. Dobrą efektywność uzyskano poprzez selekcję ramek z mową oraz zerowanie zakresów częstotliwości w których sygnał zakłócający maskuje sygnał mowy. Jego zaletą jest możliwość precyzyjnego obliczania czasu opóźnienia. Eksperymenty w warunkach rzeczywistych pokazują dobrą odporność zaproponowanego algorytmu na szum i pogłos.

6

Source localization and sensor placement in environmental monitoring

Khapalov A.

International Journal of Applied Mathematics and Computer Science

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2010

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Vol. 20, no 3

445-458

EN

In this paper we discuss two closely related problems arising in environmental monitoring. The first is the source localization problem linked to the question How can one find an unknown 'contamination source'? The second is an associated sensor placement problem: Where should we place sensors that are capable of providing the necessary 'adequate data' for that? Our approach is based on some concepts and ideas developed in mathematical control theory of partial differential equations.