Searched for: subject:"Acoustics"
(1 - 20 of 191)

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Saeedifar, M. (author), Mansvelder, Jasmijn (author), Mohammadi, R. (author), Zarouchas, D. (author)
This study aims to use the passive and active acoustic-based health monitoring methods for impact damage assessment of composite structures. To this aim, a Carbon Fiber Reinforced Polymer (CFRP) composite plate was fabricated and subjected to a simulated low-velocity impact by performing repeated quasi-static indentation tests where a loading...
journal article 2019
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Suresh Kumar, C. (author), Fotouhi, Mohamad (author), Saeedifar, M. (author), Arumugam, V. (author)
This paper investigates the effect of temperature and hybridization on the impact damage evolution and post-impact residual strength of hemp/epoxy, basalt/epoxy and their hybrid laminates, using mechanical and acoustic emission (AE) based analysis. To start with, the specimens were impacted by a drop weight impact tower machine at two...
journal article 2019
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Shamasundar, R. (author)
Demand for hydrocarbon fuel is predicted to keep increasing in the coming decades in spite of easily accessible alternative fuels due to shifting geopolitical and economic situations. In order to find new hydrocarbon pockets, we need sharper images of earth’s subsurface. Also, the exploration of other sources of energy like geothermal will...
doctoral thesis 2019
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Koop, L. (author), Amiri Simkooei, A. (author), van der Reijden, K. J. (author), O’Flynn, Sarah (author), Snellen, M. (author), Simons, D.G. (author)
High resolution maps of sandy seafloors are valuable to understand seafloor dynamics, plan engineering projects, and create detailed benthic habitat maps. This paper presents multibeam echosounder backscatter classification results of the Brown Bank area of the North Sea. We apply the Bayesian classification method in a megaripple and sand...
journal article 2019
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Merino Martinez, R. (author), Sijtsma, P. (author), Rubio Carpio, A. (author), Zamponi, Riccardo (author), Malgoezar, A.M.N. (author), Snellen, M. (author), Schram, Christophe (author), Simons, D.G. (author)
Most acoustic imaging methods assume the presence of point sound sources and, hence, may fail to correctly estimate the sound emissions of distributed sound sources, such as trailing-edge noise. In this contribution, three integration techniques are suggested to overcome this issue based on models considering a single point source, a line...
journal article 2019
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Hassan, A.M. (author), Ayoub, M. (author), Eissa, M. (author), Musa, Tagwa (author), Bruining, J. (author), Zitha, P.L.J. (author)
This paper deals with on line viscosity measurements using integrated circuit technology, and is building on a previous paper on the use radio frequency identifier (RFID) technology for determining dielectric coefficients. It is asserted that the progress in RFID technology and integrated circuits, in particular in micro–electro–mechanical...
journal article 2019
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van der Neut, J.R. (author), Fokkema, J.T. (author), van den Berg, P.M. (author), Zapf, M (author), Ruiter, Nicole V (author), Taskin, U. (author), van Dongen, K.W.A. (author)
Synthetic-aperture (SA) imaging is a popular method to visualize the reflectivity of an object from ultrasonic reflections. The method yields an image of the (volume) contrast in acoustic impedance with respect to the embedding. Typically, constant mass density is assumed in the underlying derivation. Due to the band-limited nature of the...
journal article 2019
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Zhang, L. (author), Slob, E.C. (author)
We have derived a scheme for retrieving the primary reflections from the acoustic surface-reflection response by eliminating the free-surface and internal multiple reflections in one step. This scheme does not require model information and adaptive subtraction. It consists only of the reflection response as a correlation and convolution operator...
journal article 2019
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Hedayati, R. (author), Rubio Carpio, A. (author), Luesutthiviboon, S. (author), Ragni, D. (author), Avallone, F. (author), Casalino, D. (author), van der Zwaag, S. (author)
Studies on porous trailing edges, manufactured with open-cell Ni-Cr-Al foams with sub-millimeter pore sizes, have shown encouraging results for the mitigation of turbulent boundary-layer trailing-edge noise. However, the achieved noise mitigation is typically dependent upon the pore geometry, which is fixed after manufacturing. In this study,...
journal article 2019
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Han, J. (author), Zhang, Lingling (author), Zhang, Qunfei (author), Leus, G.J.T. (author)
Orthogonal signal-division multiplexing (OSDM) is a generalized modulation scheme to bridge the gap between orthogonal frequency-division multiplexing (OFDM) and single-carrier frequency-domain equalization. It allows significantly more flexibility in system design; however, over doubly-selective channels, it suffers from a special signal...
journal article 2019
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Zhang, J. (author), Koutrouvelis, A. (author), Heusdens, R. (author), Hendriks, R.C. (author)
In this letter, we propose a decentralized framework for rate-distributed linearly constrained minimum variance (LCMV) beamforming in wireless acoustic sensor networks. To save the energy usage within the network, we propose to minimize the transmission cost and put a constraint on the noise reduction performance. Subsequently, we...
journal article 2019
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Zhang, L. (author), Thorbecke, J.W. (author), Wapenaar, C.P.A. (author), Slob, E.C. (author)
We have developed a scheme that retrieves primary reflections in the two-way traveltime domain by filtering the data. The data have their own filter that removes internal multiple reflections, whereas the amplitudes of the retrieved primary reflections are compensated for two-way transmission losses. Application of the filter does not require...
journal article 2019
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Duan, Zhiyao (author), Essid, Slim (author), Liem, C.C.S. (author), Richard, Gael (author)
In the physical sciences and engineering domains, music has traditionally been considered an acoustic phenomenon. From a perceptual viewpoint, music is naturally associated with hearing, i.e., the audio modality. Moreover, for a long time, the majority of music recordings were distributed through audio-only media, such as vinyl records,...
journal article 2019
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Manzaneque Garcia, T. (author), Lu, Ruochen (author), Yang, Yansong (author), Gong, Songbin (author)
This paper demonstrates low-loss acoustic delay lines (ADLs) based on shear-horizontal waves in thin-film LiNbO <sub>3</sub> for the first time. Due to its high electromechanical coupling, the shear-horizontal mode is suited for producing devices with large bandwidths. Here, we show that shear-horizontal waves in LiNbO <sub>3</sub> thin...
journal article 2019
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Han, J. (author), Chepuri, S.P. (author), Zhang, Qunfei (author), Leus, G.J.T. (author)
Orthogonal signal-division multiplexing (OSDM) is a promising modulation scheme that provides a generalized framework to unify orthogonal frequency-division multiplexing (OFDM) and single-carrier frequency-domain equalization. By partitioning each data block into vectors, it allows for a flexible configuration to trade off resource management...
journal article 2019
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Brand, Evelien (author), De Sloover, Lars (author), De Wulf, Alain (author), Montreuil, Anne Lise (author), Vos, S.E. (author), Chen, Margaret (author)
Sediment transport is a key element in intertidal beach morphodynamics, but measurements of sediment transport are often unreliable. The aim of this study is to quantify and investigate cross-shore sediment transport and the resulting topographic changes for a tide-dominated, sandy beach. Two fortnight-long field experiments were carried out...
journal article 2019
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Luesutthiviboon, S. (author), Malgoezar, A.M.N. (author), Merino Martinez, R. (author), Snellen, M. (author), Sijtsma, P. (author), Simons, D.G. (author)
The recently introduced high-resolution (HR)-CLEAN-SC algorithm for acoustic imaging provides ‘super-resolution’, i.e. the ability to discern sound sources located closer than the Rayleigh resolution limit. This is achieved by allowing the source markers to be relocated from the actual source locations within a certain constraint to avoid the...
journal article 2019
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Gaida, T.C. (author), Ali, Tengku Afrizal Tengku (author), Snellen, M. (author), Amiri Simkooei, A. (author), van Dijk, T.A.G.P. (author), Simons, D.G. (author)
Multi-frequency backscatter data collected from multibeam echosounders (MBESs) is increasingly becoming available. The ability to collect data at multiple frequencies at the same time is expected to allow for better discrimination between seabed sediments. We propose an extension of the Bayesian method for seabed classification to multi...
journal article 2018
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Bui, T.H. (author)
The thesis focuses on the investigation of thin-film surface acoustic wave (SAW) devices for liquid sensing applications. The piezoelectric material is a thin film of Aluminum Nitride (AlN), a CMOS compatible material, deposited by pulse DC reactive sputtering technique. A CMOS compatible process is developed and employed to fabricate the AlN/Si...
doctoral thesis 2018
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Merino Martinez, R. (author)
With the continuous growth in demand for air traffic and wind turbines, the noise emissions they generate are becoming an increasingly important issue. To reduce their noise levels, it is essential to obtain accurate information about all the sound sources present. Phased microphone arrays and acoustic imaging methods allow for the estimation of...
doctoral thesis 2018
Searched for: subject:"Acoustics"
(1 - 20 of 191)

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