bluuebunny/crossref_metadata_2025 huggingface dataset:
Proposed project to retrofit an orchestra pit with acoustic metadiffusers
Authors: VáZQUEZ AMOS Rubén , DANCE Stephen , AYGUN Haydar , BALLESTERO Eric
Published: October 2024

There is a pressing need for effective acoustic diffusion treatment with a minimal thickness profile, in particular for the retrofitting of orchestra pits. Sound can reach dangerously high levels in these environments, but highly absorptive boundaries in an orchestra pit are usually
not desirable, among other reasons because it compromises ensemble conditions. Implementing diffusion retroactively would be difficult, as there is often little space for such treatment. Acoustic metadiffusers offer a promising solution to this, but lack real-world testing and scalable production.
This paper describes this knowledge gap, with a view to ultimately creating a target sound field optimised for musician's performance and safety. This would be made possible by the inherent flexibility of metamaterial design concepts, pointing towards the future development of metadiffusers,
specifically as regards to their practical implementation. The aim is to be able to soon fill this knowledge gap, contributing to advancing the understanding of acoustic diffusion treatments. An early stage study will be the assessment of the differences between near and far fields produced
by such scattering surfaces in order to be sure of the suitability of ultra thin diffusers for use as retrofitted treatment.
Physics-informed neural networks for localized assessment in Euler-Bernoulli beams
Authors: TELOLI Rafael , VENDOLA Etienne , TITTARELLI Roberta , RAMASSO Emmanuel , OUISSE Morvan
Published: October 2024

This study employs the Physics-Informed Neural Networks (PINNs) to address an inverse problem, specifically evaluating local changes in material properties within an Euler-Bernoulli beam through numerical simulations. In our numerical model, a viscoelastic material is strategically
introduced to a localized zone of the beam, inducing non-constant and complex alterations in the storage modulus. The training process incorporates the partial differential equation into the neural network's loss function, coupled with essential stability conditions for the machine learning
model, enhancing the efficiency of the training process. Notably, this methodology excels in characterizing structural behavior influenced by these intricate local changes in material properties, bypassing the need to identify the entire structure and consequently to deal with uncertainties
related to boundary conditions. The effectiveness of the approach is validated through numerical simulations, underscoring its potential for applications in efficiently assessing and understanding local material alterations within complex structural systems.
Can sound field amplification be of use in daycare centres? An explorative pilot study
Authors: BöCKERMAN Sandra , LYBERG-ÅHLANDER Viveka
Published: October 2024

This study evaluates the effects of Sound Amplification Systems (SFA) on reducing vocal strain in daycare staff and enhancing children's concentration in noisy environments. Utilizing a mixed-methods approach, structured questionnaires were distributed to 11 daycare staff members in
Turku, Finland, to gather both quantitative and qualitative data on their experiences with SFA. The analysis revealed that SFA significantly lowered vocal strain for staff, especially during group activities, and improved children's engagement by making speech more intelligible amidst background
noise. However, practical challenges such as SFA mobility and adaptability in diverse settings were identified. The findings suggest SFA's potential benefits in early childhood educational settings, while also highlighting the need for further research to address implementation challenges
and confirm these preliminary results with a larger participant sample.
Enhancing SONAR performance through statistically-informed sub-array processing
Authors: L'HER Alexandre , DRéMEAU Angélique , LE COURTOIS Florent , REAL Gaultier , CRISTOL Xavier , STéPHAN Yann
Published: October 2024

Ocean fluctuations affect acoustic propagation and reduce the performance of SONAR arrays. In particular, internal waves can lead to a loss of coherence in incident signals, reducing the efficiency of classical processing. Precise knowledge of the environment is necessary to predict
the degradation it causes. However, it is impossible to know the exact state of the ocean, it is therefore necessary to use statistical methods to study the ocean and acoustic propagation. In this work, statistical method, canonical correlation analysis (CCA), is used to find linear relationships
between acoustic variables of interest and oceanographic measurements. In particular, the coherence radius is inferred from empirical modes of temperature using the model learned by CCA. A sub-array processing scheme can then be informed by defining the length of the sub-arrays from the coherence
radius. To compensate for the loss of angular resolution inherent in sub-arrays, we introduce the use of a Bayesian algorithm exploiting l0 norm regularization. We show on experimental data from the ALMA 2017 campaign that the proposed processing improves detection when signal coherence is
low.
Dynamic substructuring for visco-elastic materials using a POD-based model reduction method: application to laminated panels
Authors: PERREY-DEBAIN Emmanuel , BERTHET Alexandre , CHAZOT Jean-Daniel , GERMèS Sylvain
Published: October 2024

Dynamic substructuring is now a well established and powerful tool for engineers used to analyze the dynamic response of mechanical systems. The technique is particularly favored for the simulation of mechanical vibrations allowing different aspects to be studied. It consists in splitting
the global structure into several substructures from which reduced models are built. In Finite Element software, these reduced models, also called superelements, are generally built using the concept of Component Mode Synthesis. Difficulties arise when structures made of frequency-dependent
materials are considered since classical modal reduction algorithms are inapplicable as they are because of the frequency-dependence of the stiffness matrix. Based on the Balanced Truncation approach, a novel methodology for the construction of a superelement for the dynamic analysis of elastic
structures made with viscoelastic materials is presented. The methodology takes advantage of the Golla-Hughes-McTavish rheological model (GHM) before reducing the system via the Balanced Proper Orthogonal Decomposition (BPOD). The coupling of the superelement with a host structure is achieved
via the use of Lagrange multipliers. The reduced system takes the form of a constant matrix of very small size compared to the original FE model. The method is applied to laminated panels such as an automobile windscreen.
Optical interferometry based acoustic field characterization using physics informed neural networks
Authors: VERBURG Samuel A. , FERNANDEZ-GRANDE Efren , GERSTOFT Peter
Published: October 2024

The acousto-optic effect offers a non-contact way of measuring and visualizing acoustic fields in transparent fluids. Acoustic density fluctuations induce changes in the media's refractive index that can be measured using interferometry. While sensing methods based on acousto-optics
have gathered increasing attention, many of such methods are only sensitive to projections of the acoustic field along the optical path, limiting the fields that can be characterized to one or two dimensions, or requiring complex experimental setups. Recently, reconstruction methods that abide
by the physics of acoustic wave propagation showed unparalleled performance compared with classical reconstruction methods, reducing the sampling requirements and enabling to characterize three-dimensional acoustic fields. Nonetheless, such reconstruction methods rely on discrete approximations
which might be poor at describing spatially complex fields. In this work we use physics-informed neural networks (PINNs) to estimate the acoustic pressure over space from interferometer measurements. The network is flexible enough to represent complex acoustic fields, while its output is constrained
to fulfill the wave equation. Once trained on the data available for a given experiment, the PINN can estimate the acoustic pressure at arbitrary positions. The approach is tested in an experimental study, showing an improved performance compared with state-of-the-art reconstruction methods.
Experimental assessment of isolation performance of a building above metro lines: a case study with dual isolation levels
Authors: MASOUMI Hamid , VERBRAEKEN Karolien , MOTAL Tomas , ŠNAJDR Karel
Published: October 2024

This paper presents an assessment of the acoustic performance of a five-story residential building constructed directly above a metro line in Prague. The building has been isolated at two levels: first, on top of the distribution beams above the metro tunnel and secondly, at the ground
floor. The assessment of the building's performance has been conducted by a direct measurement of ground borne noise radiated inside the rooms and evaluating the vibration transmission loss through the isolation system. The transmission loss assessment was carried out using two different test
setups. Firstly, during train pass-byes, ground borne vibrations were simultaneously measured at various locations above and below the vibration cut. Secondly, at the same measurement points, the vibration levels were measured using hammer impacts. Finally, the transmissibility obtained from
both test setups was compared and discussed. Additionally, ground borne noise levels were measured inside rooms on different floors above the vibration cut. To identify noise events exclusively associated with train pass-byes, data obtained from synchronized vibration measurements at the center
of a room inside an apartment were used. Finally, the measured noise levels were compared with the limit values of noise exposure recommended by the Czech standards.
Using the Boundary Element Method for airfoil trailing edge noise prediction
Authors: BERTAGNOLIO Franck
Published: October 2024

This study investigates two aspects of the prediction of trailing edge noise from an airfoil using the Boundary Element Method to solve the scattering phenomenon. The first one consists in defining the surface pressure spectrum near the trailing edge as a source for the turbulent boundary
layer-trailing edge interaction, using either an empirical model or one-dimensional turbulent boundary layer theory. The second aspect focuses on the capability of the Boundary Element Method to handle general boundary conditions. It is applied to predict the noise emitted by a porous trailing
edge. This work is conducted in the context of aerodynamic noise from wind turbine blades, but has a wider range of engineering applications.
Noise-reducing double-layer porous pavement with steel slag as aggregate in the top layer
Authors: SANDBERG Ulf
Published: October 2024

This paper presents results of a trial replacing the natural aggregate in the top layer of a double-layer porous asphalt pavement with steel slag. A 200 m long motorway section was paved with this material and performance in terms of macrotexture and noise properties (made annually
with the CPX method) were monitored for an entire life-cycle of 7 years. The results in terms of noise reduction compared to the common Swedish reference pavement (SMA16) indicated an initial noise reduction of about 7 dB; only marginally lower than the same pavement with normal natural aggregate.
By time, this marginal loss in noise reduction was turned into a somewhat higher noise reduction after 5-6 years of service. This was surprising since the steel slag pavement appeared to clog a little more than the conventional double-layer asphalt pavement. Probably, there are (uncertain)
properties in the slag material which balances out the clogging effect. At the present time this pavement has reached an age of 7 years, which is similar as the conventional porous pavement has served on the same road over two lifecycles so far. With its lower noise-reducing deterioration
versus time, steel slag is a promising material for recycling in this way.
Double-tuning the inlet and outlet extension lengths of a family of straight-flow expansion chamber mufflers for broadband attenuation
Authors: KUMAR Randhir , MIMANI Akhilesh
Published: October 2024

This work presents a generalized end-correction expression for double-tuning the extensions of the concentric inlet and concentric/offset outlet ports of a family of straight-flow circular and elliptical expansion chamber mufflers as a function of geometrical parameters, which include
the wall-thickness, ratio of chamber-to-port diameter, aspect-ratio, and the offset distance along the major-axis. To this end, first, the transmission loss (TL) performance of configurations with non-tuned extensions given by half and quarter chamber lengths at the inlet and outlet, respectively,
was determined using 3-D FEA, which accounted for the multi-dimensional acoustic field at area-discontinuities. The effective lengths of the quarter-wave resonators at the inlet and outlet and the corresponding end-corrections were computed from the first and second resonance frequency peaks,
respectively. The 3-D FEA showed that by considering geometric length equal to the effective inlet and outlet length, three-fourths of the troughs in the TL spectrum were nullified, thereby delivering a broadband attenuation. The 3-D effects were incorporated into the 1-D model through end-correction
lengths. Parametric studies were conducted to examine the variation of end-corrections with different geometrical parameters, while the accuracy of the generalized end-correction expression was demonstrated by comparison against previous results.
Rolling noise minimization for railway wheels with constrained layer damping treatments
Authors: GARCIA-ANDRéS Xavier , MARTíNEZ-CASAS José , DENIA Francisco David , PIERINGER Astrid
Published: October 2024

The present work analyses the reduction of the radiated rolling noise by a Constrained Layer Damping (CLD) mounted on the railway wheel. For this purpose, a methodology has been developed combining the use of viscoelastic models that consider the dependence of the material properties
on frequency with an integral vibroacoustic model of the wheel. The CLD device, composed by a layer made of a viscoelastic material constrained towards the web by a steel layer positioned on the top, is characterised by design parameters considered relevant for sound radiation. The sound power
level (SWL) is computed for different configurations of CLDs on the wheel to find the optimal designs for rolling noise minimisation.
Sandwich structures in bio-composite material for sustainable acoustic solutions
Authors: DI GIULIO Elio , NAPOLITANO Marialuisa , BOCCARUSSO Luca , DURANTE Massimo , ROMANO Rosario Aniello , DRAGONETTI Raffaele
Published: October 2024

The use of bio-based materials in acoustic applications has gained a lot of attention recently as a functional and environmentally friendly alternative for synthetic materials. This is because conventional synthetic fibers have a significant impact on the environment and the health
risks of people. The focus is now on developing composite systems that minimize environmental harm by using energy and materials more efficiently, and by substituting synthetic or petroleum-based materials with more sustainable options, such as natural fibers. These natural fibers are favoured
for their biodegradability, sustainability, and widespread availability, earning them the label of "green materials." Thus, this paper aims to investigate the soundproofing capabilities of a novel sandwich structure composed of hemp fibers and bio-epoxy resin, aiming to broaden the
application field of natural fiber composite materials.
Microstructure design of a stack for independent control of thermal and viscous phenomena
Authors: DI GIULIO Elio , NGUYEN Cong Truc , DRAGONETTI Raffaele , PERROT Camille
Published: October 2024

\textit{Thermal and viscous energy conversion in a thermoacoustic device occurs inside a particular porous material, named stack/regenerator. Viscous losses and thermal exchanges arise thanks to the interaction of an acoustic field and the solid skeleton of a porous material. Its microstructure
strongly influences the amount of energy which can be converted or dissipated due to viscous and thermal boundary layers. Thermal and viscous losses are strictly interconnected, meaning that by altering the pore size (i.e. the hydraulic radius) of the microstructure, both thermal and viscous
effects are generally affected. However, there are cases where independent control of thermal or viscous effects could be crucial such as in the thermoacoustics devices. Enhancing heat exchanges while minimizing viscous losses becomes necessary to enhance power conversion. This work paves
the way to the design of a microstructure suitable for controlling viscous and thermal effects in a relatively independent way.
Impact of contextual and lip-sync-related visual cues on speech intelligibility through immersive audio-visual scene recordings in a reverberant conference room
Authors: GUASTAMACCHIA Angela , GALLETTO Andrea , RIENTE Fabrizio , SHTREPI Louena , PUGLISI Giuseppina Emma , ALBERA Andrea , ASTOLFI Arianna
Published: October 2024

Recent hearing research has benefitted from the latest Virtual Reality systems that allowed the reproduction of immersive Audio-Visual scenarios to achieve more ecological listening tests. Indeed, efforts have been spent to identify the aspects that convey actual ecological validity,
particularly investigating the effects of visual cues and self-motion on Speech Intelligibility through tests mainly based on simulated scenes. However, work must still be addressed when sceneries developed through real recordings inside reverberant environments are concerned. This study used
3rd-order ambisonics recordings and stereoscopic 360° videos inside a reverberant conference hall to create three virtual audio-visual scenes where speech intelligibility tests were performed, introducing informational noise from different angles. A 16-speaker spherical array synced with
a headmounted display was used to administer the immersive tests to 50 normal-hearing subjects. Firstly, tests only composed of the auditory scenes were compared, based on the achieved scores, with tests also providing contextual and positional source-related visual cues, both with and without
self-motion, for a total of four different test configurations. Then, to complete the investigation of the visual cues' impact on speech intelligibility, ten normal-hearing subjects were recruited to performaudio-visual tests incorporating lip-sync-related visual cues for the target speech.
Striking the right note: balancing AVAS in tomorrow's soundscapes
Authors: GUTIERREZ Florestan , ROBIN Xavier , CHARON Antoine
Published: October 2024

Soundscapes of tomorrow are defined now. Not just a mobile sonic brand signature, the AVAS is also an attention grabber and an imposed alert. The method invoked for its design must be collaborative and involve the brand, designers, marketers, stakeholders, but also drivers, residents
and question its position in the soundscape. Defining the aesthetic with a shared semantic, listening, testing, in simulation, on road, with people, with sensors; any sound design should be the result of a collaborative process because it talks to people, improve the perceived quality of products,
and improve the quality of life. If well made. Also AVAS sound is also regulated by international standards that are defining boundaries in the selection of the right sound. The signal emitted by the AVAS loudspeaker should follow these rules, in terms of minimum level and spectrum content
at specific pedestrians' locations around the car. The simulation of the propagation of the sound from the loudspeaker to these positions in early phase of the design is important to avoid big design mistake. 3D acoustic simulations using FE acoustic software Actran and dedicated post-processing
for AVAS are performed to confirm the correct location of loudspeaker and spectral content.
The SpeaK methodology for sound design
Authors: SUSINI Patrick , HOUIX Olivier , MISDARIIS Nicolas , BARTHELEMY Romain
Published: October 2024

The first meetings of a sound design project aim to present the request which may concern the identity of a brand or the emotion associated with a new product. It is then crucial to elaborate recommendations for the sound designer. However, the major difficulty encountered is to specify
the request in terms of sound features. The Speak methodology is based on an efficient co-design workshop to help participants, ranging from the project manager to the communication manager, to specify their request with words related to sound features. Frist, a lexicon composed of 35 words
often used by professionals is presented to the participants; each word is related to a sound feature explained by a definition and highlighted by a corpus of sound examples. Then, a card game is provided to each participant; each card is associated with a word from the lexicon. The rule during
the workshop is to use only the cards to describe the desired audible intention; each participant can select or reject a word, and exchange with other participants focusing only on the sound features. Finally, participants are actively involved in the process to develop sound recommendations.
During the presentation, we will focus on a specific project.
Investigation of light earth sound transmission loss at the wall scale
Authors: GLé Philippe , BLINET Thibaut , GUIGOU-CARTER Catherine , HELLOUIN DE MENIBUS Arthur
Published: October 2024

A fine understanding of the acoustic dissipation in walls made from biobased concrete is needed to predict and design properly their performances and to create comfortable spaces. This understanding is one of the objective of LOB+HIE (LOW BETON / HIGH EARTH) project, funded by Ademe,
and focusing on the use of light earth (a biobased concrete resulting from the mix between clay and hemp shiv) to meet acoustic requirements in a public worksite. Acoustic data are already available in the literature at the material scale for this kind of solution. The aim of the present work
is to provide experimental reference data at the wall scale for sound transmission on full-scale vertical walls, and then to extend it to other configurations by numerical simulations. The work is organised in three parts, including the transmission loss measurements on two different walls,
the modelling of the walls with numerical simulations using a transfer matrix method approach, and finally the extension by simulation to other wall configurations, with a view to producing design aids for use by building professionals.
Feedback control of thermoacoustic instabilities in sequential combustor with nanosecond repetitively pulsed discharges
Authors: DHARMAPUTRA Bayu Adi , NOIRAY Nicolas , SHCHERBANEV Sergey
Published: October 2024

Controlling thermoacoustic instabilities is a necessary task for the development and operation of gas turbines. With the increasing proportion of renewable energy sources, gas turbines must have flexibility in terms of both fuel and load. This implies that thermoacoustic instabilities
must be controlled under different operating conditions. Active control strategies are indeed very suitable in this case, as they can adapt to the changes in operating conditions. Nanosecond repetitively pulsed discharges (NRPD) has shown to be promising active control actuators because they
require no moving parts. In this study, the effectiveness of feedback and open-loop control law with NRPD actuation to suppress thermoacoustic instabilities in a lab-scale sequential combustor is evaluated. The effect of the controller parameters on the NO emissions of the combustor is also
quantified. The results indicate that there is a trade-off between acoustic pulsation reduction and NO emission.
ETICS measurements and prediction - Verification and validation of a predictive model for the improvement of airborne sound insulation of thick external linings
Authors: SCROSATI Chiara , SCHIAVI Alessandro , PETTONI POSSENTI Vincenzo , BARBARESI Luca
Published: October 2024

The increasing demand of the reduction of carbon emissions and the consumption of energy resources due to the construction sector leads to the concept of Zero-Energy buildings. It is therefore crucial ensuring technical and engineering compatibility between future advancements in energy
efficiency and sound insulation. The sound insulation requirements for residential buildings are mandatory in Italian Regulations, tested on-site after construction completion. A noteworthy challenge is the potential synergy between specifications for energy efficiency and the sound insulation
properties in building materials. This paper deals with the validation of the prediction model for the improvement of airborne sound insulation due to thick external linings, particularly materials used in ETICS (External Thermal Insulation System), based on mechanical properties of involved
materials. Standard ISO 9052-1 for the determination of dynamic stiffness is intended for materials used under floating floors in dwellings. However, based on the methods of this standard, it is possible to perform measurements (with both hammer and shaker) even on thick linings materials,
and use the results for the implementation of computational models for the predictions of airborne sound insulation improvement, as a function of frequency, with good accuracy.
Synthesizing source directivity using DeepONet room acoustic predictions
Authors: BORREL-JENSEN Nikolas , MEYER-KAHLEN Nils
Published: October 2024

Incorporating source directivity when simulating spatial room impulse responses for virtual environments is crucial for achieving natural results. Directly injecting the directional source as the initial condition for a wave equation to solve would require re-running a numerical solver
for each new directivity pattern, source position or orientation. Here we show that learned surrogate models can lead to large efficiency benefits if such variation shall be simulated. Although training such models is a computationally expensive process, performing inference over them is typically
fast. Here we show how to exploit that property by training a deep neural operator network (DeepONet) only using omni-directional sources, and predicting the pressure on a variable grid of points, to which directivity filters are applied to generate arbitrary patterns. We show the fit of directictivity
patterns to their re-synthesized versions from the output of a DeepONet.
A positive semi definite tensor factorization method for separation of non stationary noise sources
Authors: ROUAL Sarah , CHARDON Gilles , SOUSSEN Charles , SENSIAU Claude
Published: October 2024

In the aircraft industry, noise mitigation has emerged as an increasingly pressing issue, underscoring the critical importance of advancing our understanding of noise origins within turbofan engines. This paper presents the application of Positive Semi Definite Tensor Factorization
(PSDTF), a potential method for the analysis of engine static tests conducted with far-field microphone arrays. By extending the capabilities of Non-negative Matrix Factorization (NMF), PSDTF offers an effective algorithm for source separation. Leveraging on cross spectral matrices to harness
phase information across microphones, this approach aims at separating the contributions of several noise sources, avoiding the need for a precise acoustical model (sound propagation, source directivity, etc.). Experimental findings on a controlled experiment demonstrate the superiority of
PSDTF over conventional NMF variants in achieving higher-quality source separation.
Perceptual attributes for soundscape assessment: translation into Portuguese
Authors: MICHALSKI Ranny , ANTUNES Sonia , ALVES Sonia , CARVALHO Maria Luiza
Published: October 2024

Soundscapes have been a growing tool in managing urban sounds through the ISOs series 12913 parts 1 to 3. The ISO/TS 12913-2: 2018 standard (Acoustics - Soundscape - Part 2: Data collection and reporting requirements) provides technical specifications and protocols, as well as a questionnaire
for soundscape characterization with perceptual attributes based on soundscape studies. However, such attributes are provided only in the English language, which raises questions about the applicability and reliability of these attributes in regions where English is not the mother tongue.
To address this gap, the Soundscape Attribute Translation Project (SATP), an international collaboration with soundscape researchers was established with the aim of validating the translation of perceptual attributes for soundscape assessment in different languages and geographic regions as
a way of disseminating and promoting their widespread use, both in academia and in practice. This article presents the results of the work, realized in Brazil and Portugal, contributing to the translation of the perceptual attributes for soundscape assessments from English into Portuguese
language through a cross-cultural study.
Hierarchical porous metamaterial for sound absorption
Authors: KUZNETSOVA Svetlana , ALLEIN Florian , DELEPLANQUE Samuel , DUBUS Bertrand , MINIACI Marco
Published: October 2024

Absorption of sound is of great importance in several engineering applications, from room acoustics to engine noise reduction. Porous media are practical and commonly used to address this issue. However, their performance is limited at large wavelengths, where more material is required.
Inspired by recursive patterns at multiple scale lengths, typical of many biological systems, we propose here a new design based on hierarchical multilayered porous materials. Two hierarchical designs are investigated: periodic and gradient. In both cases it is found that the increase of the
hierarchy level allows to simultaneously (i) increase the absorption, and (ii) reduce the quantity of porous material required. Both the cases of normal and oblique incidences are examined. The absorption coefficient is calculated via the transfer matrix method and the finite element method,
supporting measurements in an impedance tube. The porous media are described through the JCA model. An optimization algorithm based on the metaheuristic Greedy Randomized Adaptive Search Procedure is developed to optimize the organization of the porous layers, and practical tips are given
on the most suitable choice of parameters (static air-flow resistivity, angle of incidence) to obtain the highest absorption amplification at desired low frequencies.
Designed honeycomb lattice for improving vibration control
Authors: PEREIRA DA SILVA Carlos Eduardo , RODRIGUES MACHADO Marcela , MUKHOPADHYAY Tanmoy
Published: October 2024

Honeycombs represent common cellular structures characterised by two-dimensional arrays of unit cells arranged in-plane and stacked parallelly in the out-of-plane direction, exhibiting a periodic structure. Due to the interconnected network of these unit cells, honeycombs possess higher
porosity and lower mass density than their matrix materials, resulting in superior specific stiffness/strength and specific energy absorption. The arrangement of repeating unit cells profoundly impacts the mechanical properties of these lightweight materials. This study explores a 2D metamaterial
cellular system inspired by the lightweight characteristics of honeycombs. In this system, squared honeycomb cells with additional lumped masses can influence vibrating modes. Unlike conventional methods employing discrete mass-spring resonators, this approach intentionally adds masses to
create complete or incomplete stop bands wherein wave propagation is either wholly or partially suppressed along specific directions. The dispersion curves of wave bands and the sensitivity of bandgaps concerning design parameters are estimated using the finite element method and Block's theorem.
Numerical simulations demonstrate the stop band behaviour, providing insights for optimisation strategies and a deeper comprehension of these remarkable cellular material systems and improvements in the design with enhanced vibro-acoustics performance and control.
Systematic analysis of acoustic source localization maps for performance assessment
Authors: PARISOT-DUPUIS Hélène , JOMAIN Jérémy , MELLOT Bertrand , MERY Fabien
Published: October 2024

Noise pollution is a raising problematic mainly associated to the development of industry, cities, and transportation. In that context, the characterization of noise sources is key point to help the understanding of noise generation mechanisms and to be able to develop effective noise
reduction strategies. Microphones phased array measurements can be used as input to solve the inverse problem of source localization allowing to obtain source maps for each frequency of interest. Conventional beamforming (CBF) is the most famous source localization algorithm which uses the
interpretation of the propagation delays measured between each array microphones. However, the analysis of output source maps can be made difficult by the low spatial resolution in the low-frequency range and the presence of side-lobes associated with microphones distribution that can lead
to additional wrong sources. This paper presents a systematic analysis of source maps to identify potential noise sources by using different methods (local maxima, Metropolis-Hastings). The set of potential noise sources can then be compared to the set of real sources to assess the CBF performances.
This methodology is successfully applied to measurements performed in anechoic room for various source configurations highlighting CBF limitations (spatial resolution, correlated sources, reflective environment).
Band structures based phononic crystals in quasi-Sierpinski fractals with defects
Authors: DOS SANTOS Victor , DOS SANTOS José , MIRANDA JUNIOR Edson
Published: October 2024

This study presents a detailed analysis of the effects of geometric defects in phononic crystals, focusing on the use of a distribution of Sierpinski fractals for the strategic placement of inclusions. Using theoretical and computational approaches, we investigate the influence of these
defects on the material's band structure. Phononic crystals, designed based on fractal geometry inspired by the Sierpinski pattern, are particularly sensitive to the introduction of inclusions, resulting in disorder in the periodic structure. Our study examines in detail how different defect
configurations affect the formation of localized modes and the energy distribution in the material's band structure. The results obtained provide valuable insights into how the presence of geometric defects can be exploited or minimized in the design of phononic crystals for practical applications,
including acoustic isolation, vibration control, and the development of advanced acoustic devices. These results contribute to the understanding and advancement of fractal phononic crystals, paving the way for future research and promising technological applications, both in terms of frequency
and attenuation, depending on the complexity and hierarchy of the fractal structures used.
Theoretical investigation of new composite based on metamaterial able to strongly attenuate heat and noise propagation for civil engineering
Authors: RASOANOAVY Faliniaina
Published: October 2024

New design in civil engineering need reduction of cost of material. Engineers and researcher are focused on material parameter to improve proposed alternatives. In this work we are developed theoretical tool based on finite element method to evaluate transmission noise and heat transfer
along composite wall for civil engineering. In this work, composite based metamaterial is used for wall elaboration. At first Time noise level in broad band high frequency level was extracted using frequency acoustic finite element method, and using advection, diffusion model heat transfer
distribution was also extracted. Finally, combination of constitutive model with metaheuristic optimization enabled us optimal parameters of the material composite, for specific condition. Constitutive resulted and discussion will have detailed in the paper. Keywords: frequency acoustic analysis,
advection diffusion, genetic algorithm, civil engineering, material science, metamaterial
The European DeuteroNoise project: impact of anthropogenic noise on marine invertebrate deuterostomes
Authors: ZAMBON Giovanni , BENOCCI Roberto , SABBADIN Giacomo , MANNI Lucia , CANDIANI Simona , BOZZO Matteo , PENNATI Roberta , CHATZIGEORGIOU Marios , NORLAND Sissel , CAVAZOS CONTRERAS Ingrid Margarita , RISTORATORE Filomena , SPAGNUOLO Antonietta , ZAFFARONI CAORSI Valentina
Published: October 2024

Underwater noise is considered an emergent pollutant negatively affecting marine fauna; however, its effects on marine invertebrates are almost unknown. In the frame of the project DeuteroNoise, financed by JPI Oceans, we tested the effects of anthropogenic underwater noise on the behavioral
performances and physiology of Deuterostome species. Experimental designs for noise exposure in the laboratory were performed inside tanks and directed toward each species studied. For all species, the playback experiments were performed inside water tanks using an underwater speaker connected
to an amplifier and a computer. The animals were exposed to pink noise (higher intensities at 63-125 Hz) at different intensities. Behavioral and physiological responses varied among species depending on the anatomy of their sensitive system and the studied response (e.g. movement, development,
heartbeat).
Experimental validation of an hybrid analytical-numerical technique to estimate the directivity of ultrasonic piezoelectric actuators
Authors: DE BONO Emanuele , COLLET Manuel , GRANDO Jerome , EGE Kerem
Published: October 2024

The generation of guided waves is a common approach for structural health monitoring. The optimization of the excitation strategies very much benefits from the availability of efficient simulation tools. On the one hand, the application of finite elements (FEs) for the analysis of wave
propagation problems leads to large models which tend to be computationally costly for optimization studies. On the other hand, semi-analytical approaches provide useful analytical expressions for parametric studies, but may lead to inaccurate estimations of tuning frequencies and directionality,
especially at high frequencies. This is mostly because of the simplifying assumptions regarding the stress field at the interface between the actuator patches and the plate. An interesting methodology couples the analytical far-field solution of the plate response with a local FE model of
the interface stresses between plate and patches. This method allows the analysis of complex actuation configurations for various purposes, such as directivity steering. In this contribution, we experimentally validate such hybrid FE-analytical technique. A Scanning Laser Doppler velocimeter
is employed to retrieve both temporal and spatial Fourier Transforms on a polycarbonate plate, excited by piezoelectric patches, and the directivity patterns of the first symmetric and antisymmetric modes are compared to the numerical predictions.
Mind map for cross-reading the glossary of urban morphology and soundscape research
Authors: BICER Nehir Bera , ALANYALI ARAL Ela
Published: October 2024

Urban morphological research has a long-established and systematic method of analysis that provides a clear and shared research framework. Since the late 1990s, the International Seminar on Urban Form (ISUF) has compiled a glossary of urban morphology for the agenda of urban researchers.
The soundscape literature emerged in the late 1960s and early 1970s. Since then, there have been numerous studies dealing with the sonic dimension of urban complexity from different perspectives. In order to create an overarching framework, attempts have been made since the early 1970s to
define the principles and processes of soundscape research. There is a comprehensive glossary created by the Wold Soundscape Project Team (WSP) in 1978 which has been of great importance for further soundscape studies. This paper argues that there is a link between urban morphology research
and soundscape research. A cross-reading between the two glossaries therefore has the potential to offer an alternative reading of urban research by revealing the commonalities or differences in the sonic-morphological conceptual schemes.
Acoustic scene analysis of spatial and temporal distribution of sound arrival direction and frequency spectra
Authors: SAKODA Keishi , ICHIRO Yamada
Published: October 2024

In the outdoor monitoring of aircraft noise, not only the target aircraft sounds to be monitored arrive, but also various environmental sounds also arrive at the monitoring site, and the sound situation changes from moment to moment. The authors have studied and reported on a method
to classify environmental sound sources and to evaluate the influence of environmental sounds on aircraft sound monitoring by analyzing the spatial-temporal distribution of sound arrival direction and sound level of various environmental sounds at the monitoring site as a sound scene. This
paper will make a report on a result of the acoustic scene analysis by using the sound spectra as additional input data in the scene analysis. We will also explain about a procedure for automatic classification of sound sources using the result of the scene analysis briefly.
On application of sound power radiation of rolling tyre measured using CPX-based methodology
Authors: LEUNG Randolph Chi Kin , RAI Sanjaya , LI Dong Fang
Published: October 2024

The present paper provides a comprehensive account of sound power radiation measurement from a rolling tyre, utilising a methodology that employs an advanced PolyU Mark III Close-Proximity (CPX) trailer enclosure which is aimed to provide CPX measurement per relevant ISO stsandard with
suppressed background noise within the interior. The interior walls and ceiling of the enclosure are equipped with diffuser panels, creating a reverberant environment suitable for sound power measurement using the comparison method. The optimal design of the enclosure, which minimizes acoustic
resonance and ensures a uniform distribution of acoustic energy, is determined through extensive numerical simulations. During tyre/road sound power measurements, the spatially averaged sound pressure level (SPL) distributions within the enclosure are obtained with a reference sound source
(RSS) of known sound power. The relationships between the RSS SWLs and the corresponding SPLs are established at all vehicle speeds. These relationships can then be utilised to deduce the total SWL, as well as its 1/3-octave spectrum, from the captured averaged SPL radiated by a tyre rolling
at any vehicle speed. The effectiveness of the CPX-based sound power measurement are illustrated. Additionally, the potential of utilising the measured SWLs for predicting pass-by noise radiation to roadside is discussed.
Characterisation and simulation of a general ventilation filter based on a double porosity approach
Authors: BéCOT François-Xavier , CHEVILLOTTE Fabien , BESSAC François , GINESTET Alain
Published: October 2024

The air filters installed in ventilation systems are designed for collecting dust and particles. These filters usually consist in folded paper or textile, arranged either as a flat slab or in a V-shape frame. Some of them may also contain activated carbon in order to remove molecular
compounds. Experimental results show that they can significantly attenuate the upstream sound sources such as fans or other regenerated noise. Though, these acoustic properties are not strictly speaking designed and often result from the tailored filtering capacities. The present work proposes
a three-stage methodology to design and optimize the acoustic performance of these filters. The first stage is the characterization of the intrinsic acoustic parameters of the paper or textile. The second stage consists in the validation of these parameters regarding sound attenuation as measured
in impedance tube. This includes analytical and finite element computations to correctly account for the mounting conditions of the specimen in the impedance tube. The final stage consists in predicting the sound attenuation measured on the full-size filter, set in shape using the porous composite
material theory. The obtained results provide a satisfactory correspondence allowing for an accurate design at an early stage of the project.
Analysis and suppression research of high lift device noise based on large aeroacoustic wind tunnel test
Authors: SONG Yubao
Published: October 2024

The exterior noise of large aircrafts is an important aspect for the airworthiness certification. The high-lift device is one of the key noise sources for large aircrafts, thus the analysis and reduction of high-lift device noise is important and meaningful. Based on the 5.5m×4.0m
Aeroacoustic Wind Tunnel and a half model for the aeroacoustic study of large scale aircrafts, the high-lift device noise properties were studied experimentally. First, the experimental platform, the test model, the test system and noise reduction design were introduced. Then, based on the
experimental results, the noise characteristics of the high-lift devices were analyzed. The effects on the noise from the angle of attack and the wind speed were compared. The effects on the high-lift device noise from the noise reduction design on slat and flap were investigated. The results
show that, the high-lift device noise has a broad frequency spectrum, with some peak frequency components. As the angle of attack is increased, the noise of the model is generally increased in the medium to high frequency range. With the wind speed increased, the noise is increased dramatically,
and the frequency spectra keep a good similarity. The peak noise is suppressed by the noise reduction design.
INNOVATIVE TECHNOLOGIES FOR UNMANNED SYSTEMS
Authors:   MIREA – Russian Technological University, Pushkin Pavel Yurievich , Rizaeva Yulia Nikolaevna ,   MIREA – Russian Technological University, Sukhaterin Alexey Borisovich ,   MIREA – Russian Technological University
Published: October 2024

Specialists in the motor transport industry are faced with a large-scale task of developing unmanned systems: highly automated vehicles and supporting infrastructure. The article analyzes the state policy of the formation and implementation of innovative, modern and end-to-end technologies for unmanned vehicles and road transport infrastructure. The authors provide an overview of innovative technologies presented in documents at the federal level that influence the development of unmanned systems, prospects and possibilities for their use in the motor transport industry. Innovative foreign and domestic experience in the use of modern innovative technologies in organizing freight and passenger road transport in Russia, the USA, Germany, Israel, and China is presented.
IMPROVING THE EFFICIENCY OF MANAGING THE PROCESSES OF TRANSPORTATION OF NETWORK CARGO DELIVERYBY ROAD
Authors:   Penza State University of Architecture and Construction, Zhestkova Svetlana Anatol’evna
Published: October 2024

A methodology for designing a routing problem using the method of fictitious nodes and branches, taking into account restrictions, is given. The constraints are taken into account when reciprocating through the branches of the decision tree to block the cell with the maximum estimate. The results of the application of the developed methodology are presented, using the example of cargo transportation from the administrative center located in the Penza region to retail outlets in Penza per shift.