نتایج جستجو برای: underwater acoustics

تعداد نتایج: 25089  

Journal: :The Journal of the Acoustical Society of America 1992

2014
Mark S. WOCHNER Kevin M. LEE Andrew R. MCNEESE Preston S. WILSON

This paper investigates the acoustic behavior of underwater air-filled resonators that could potentially be used in an underwater noise abatement system. The resonators are similar to Helmholtz resonators without a neck, consisting of underwater inverted air-filled cavities with combinations of rigid and elastic wall members, and they are intended to be fastened to a framework forming a station...

Journal: :CoRR 2017
Min Xu Yong-Yian Wang Anthony T. Chronopoulos Hao Yue

As one of open-source codes widely used in computational ocean acoustics, FOR3D can provide a very good estimate for underwater acoustic propagation. In this paper, we propose a performance optimization and parallelization to speed up the running of FOR3D. We utilized a variety of methods to enhance the entire performance, such as using a multi-threaded programming model to exploit the potentia...

2009
S. Bourennane A. Bendjama

This paper deals with the localization of the wideband sources. We develop a new approach for estimating the wide band sources parameters. This method is based on the high order statistics of the recorded data in order to eliminate the Gaussian components from the signals received on the various hydrophones. In fact the noise of sea bottom is regarded as being Gaussian. Thanks to the coherent s...

2014
L. Godinho A. Pereira Delfim Soares

Several numerical and analytical models have been used to study underwater acoustics problems. The most accurate and realistic models are usually based on the solution of the wave equation using a variety of methods. Here, a hybrid numerical-analytical model is proposed to address the problem of underwater sound scattering by an elastic shell structure, which is assumed to be circular and that ...

2011
Venkatesh Vadde Bhagya Lakshmi

Underwater acoustic signals need transducers to generate and detect signals with high power, linearity, dynamic-range and beamwidth. Among a variety of transducer designs, a Tonpilz transducer stands out for power and long-range applications. A Tonpilz transducer for underwater acoustic signaling is developed to scale and analyzed using FEM tools with Comsol. The underlying pressure-acoustics a...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه صنعتی شیراز - دانشکده مهندسی برق و الکترونیک 1390

سیستمهای (ofdm) مالتی پلکس فرکانس متعامد به علت مقاوم بودن نسبت به پراکندگی زمانی درکانال به یک روش مدولاسیون2 قابل اعتماد برای ارتباطات اکوستیکی زیرآب تبدیل شده است. درمقایسه با سیستمهای تک حاملی سنتی که معمولا” نیازمند طرح های پیچیده جبران سازی? می باشند سیستمهای ofdmبه علت عدم نیاز به طرح های پیچیده جبران سازی به طورکلی دارای ساختار ساده تری می باشند. جابجایی فرکانسی به عنوان یکی از عوامل ...

1997
Kainam T. Wong Michael D. Zoltowski

This paper introduces a novel ESPRIT-based closedform source localization algorithm applicable to arbitrarily spaced three-dimensional arrays of vector hydrophones, whose locations need not be known. Each vector hydrophone consists of two or three identical but orthogonally oriented velocity hydrophones plus one pressure hydrophone, all spatially co-located in a point-like geometry. A velocity ...

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