Hasil untuk "Acoustics in engineering. Acoustical engineering"

Lissek Hervé, Vesal Rahim

Loudspeakers inherit their directivity from their geometry and dimensions. Enclosed loudspeakers are omnidirectional in the low frequency range, but their directivity depends on frequency for wavelengths smaller than the radiator size, precluding the directional control over the whole bandwidth. Loudspeakers pairs allow achieving simultaneously monopolar (in-phase) and dipolar (out-of-phase) sources, thus allowing directivity control. However, they are limited by their bulkiness, preventing extending controllable directivities over high frequencies. The Corona Discharge transducer (CDT) concept relies on ionizing an ultra-thin layer of air and oscillating it through an alternating electric field, generating sound without resorting to a mechanical membrane. This transducer combines a monopolar source linked to heat exchanges, and a dipolar linked to electrostatic forces, although these two sources strengths are interconnected, yielding a given unidirectional directivity. In this paper, we propose to leverage the combination of monopole and dipole at the heart of the CDT concept to achieve controllable directivities by stacking two independent CDTs. The very thin dimensions of the CDT allows achieving coincident controllable monopolar and dipolar sound sources making the control of directivity over the whole operating frequency ranges. An analytical model of the dual CDTs concept is first compared to full-wave simulations, and an experimental prototype is finally assessed in anechoic conditions. Our findings open the way to a new range of broadband directionally-controllable transducers that have application to sound generation, active noise reduction, or even non-reciprocal active acoustic metamaterials.

Jingyue Li, André Storhaug

With the advancement of Agentic AI, researchers are increasingly leveraging autonomous agents to address challenges in software engineering (SE). However, the large language models (LLMs) that underpin these agents often function as black boxes, making it difficult to justify the superiority of Agentic AI approaches over baselines. Furthermore, missing information in the evaluation design description frequently renders the reproduction of results infeasible. To synthesize current evaluation practices for Agentic AI in SE, this study analyzes 18 papers on the topic, published or accepted by ICSE 2026, ICSE 2025, FSE 2025, ASE 2025, and ISSTA 2025. The analysis identifies prevailing approaches and their limitations in evaluating Agentic AI for SE, both in current research and potential future studies. To address these shortcomings, this position paper proposes a set of guidelines and recommendations designed to empower reproducible, explainable, and effective evaluations of Agentic AI in software engineering. In particular, we recommend that Agentic AI researchers make their Thought-Action-Result (TAR) trajectories and LLM interaction data, or summarized versions of these artifacts, publicly accessible. Doing so will enable subsequent studies to more effectively analyze the strengths and weaknesses of different Agentic AI approaches. To demonstrate the feasibility of such comparisons, we present a proof-of-concept case study that illustrates how TAR trajectories can support systematic analysis across approaches.

Tanja E. J. Vos, Tijs van der Storm, Alexander Serebrenik et al.

Software engineering is the invisible infrastructure of the digital age. Every breakthrough in artificial intelligence, quantum computing, photonics, and cybersecurity relies on advances in software engineering, yet the field is too often treated as a supportive digital component rather than as a strategic, enabling discipline. In policy frameworks, including major European programmes, software appears primarily as a building block within other technologies, while the scientific discipline of software engineering remains largely absent. This position paper argues that the long-term sustainability, dependability, and sovereignty of digital technologies depend on investment in software engineering research. It is a call to reclaim the identity of software engineering.

Lili Chen, Winn Wing-Yiu Chow, Stella Peng et al.

PURPOSE OR GOAL: This study investigates how GenAI can be integrated with a criterion-referenced grading framework to improve the efficiency and quality of grading for mathematical assessments in engineering. It specifically explores the challenges demonstrators face with manual, model solution-based grading and how a GenAI-supported system can be designed to reliably identify student errors, provide high-quality feedback, and support human graders. The research also examines human graders' perceptions of the effectiveness of this GenAI-assisted approach. ACTUAL OR ANTICIPATED OUTCOMES: The study found that GenAI achieved an overall grading accuracy of 92.5%, comparable to two experienced human graders. The two researchers, who also served as subject demonstrators, perceived the GenAI as a helpful second reviewer that improved accuracy by catching small errors and provided more complete feedback than they could manually. A central outcome was the significant enhancement of formative feedback. However, they noted the GenAI tool is not yet reliable enough for autonomous use, especially with unconventional solutions. CONCLUSIONS/RECOMMENDATIONS/SUMMARY: This study demonstrates that GenAI, when paired with a structured, criterion-referenced framework using binary questions, can grade engineering mathematical assessments with an accuracy comparable to human experts. Its primary contribution is a novel methodological approach that embeds the generation of high-quality, scalable formative feedback directly into the assessment workflow. Future work should investigate student perceptions of GenAI grading and feedback.

Juvé Daniel, Blanc-Benon Philippe

The research team in acoustics at the École Centrale de Lyon was founded 50 years ago by Prof. Geneviève Comte-Bellot. In this paper we describe the growth of this team, now known as the Acoustic center of the École Centrale de Lyon (or Centre Acoustique in French), from the early 1970s to the present day. We highlight the evolution of the research interests and experimental facilities, and provide a selection of “historical” references at the end of the paper. The main current research topics are listed and illustrated, and are complemented by a partial list of recent references.

Pagavino Manuel, Zotter Franz

Nearfield Acoustic Holography (NAH) retrieves vibro-acoustic patterns of sound sources from non-contact measurements of sound in their proximity. NAH obtains images of structural vibrations to analyze the underlying acoustic phenomena. Holographic problems are typically ill-posed and yield infinitely many solutions. Unique solutions are obtained by optimizing a cost function that targets an approximate solution obeying the laws of physics while simultaneously satisfying constraints that represent prior knowledge characterizing the expected result. Which constraints to choose is highly critical for success, and yet the most challenging question to answer. Accuracy fluctuates with the quantity and the quality of these constraints and requires skillful formulation and tuning. Despite ongoing research on novel constraints and parameter tuning methods, as well as rapid advancements in Deep Learning, the state-of-the-art still exhibits substantial deficiencies. As the proposed solution, this article studies a Variational Network for NAH with the idea to fuse physical knowledge with data-driven modeling. The network retrieves the strengths of equivalent sources from measurements by unrolling an iterative optimizer, whose regularizing parameters are inferred via supervised learning. The proposed method outperforms established solvers in a comparative study, using both simulated and real-world data, and it generalizes well to unseen vibration patterns.

Olivon Frédéric, Genot Aurelien, Durand Jean-Étienne et al.

Thermally choked nozzles, where choking is induced by heat addition rather than a geometrical throat, are a promising solution for dual-mode ramjet transitions to hypersonic speed. Despite their relevance, thermal throat boundary conditions for quasi-one-dimensional acoustic modelling are not derived in the state-of-the-art. This study introduces a generalized critical-throat acoustic boundary condition applicable to both geometrically and thermally choked flow configurations. A dedicated one-dimensional linear acoustic solver is formulated to incorporate this condition and is validated against two-dimensional Euler simulations. Particular attention is paid to the impact of entropy and acoustic waves at the critical throat. The results show that the new boundary condition improves the prediction of acoustic reflection, entropy noise production, and transmission coefficients, especially under thermally choked conditions where the commonly used quasi-steady assumption fails. For both the thermal-throat and geometric-throat configurations, the deviation in the acoustic transmission coefficient between the linear acoustic model using the proposed boundary condition and the simulations remains below 2%, while the deviation in the entropy-noise transmission coefficient remains below 5%, demonstrating the robustness of the proposed boundary condition.

Kim Jooyoung

This study explores the influence of crossover frequency on frequency response (FR) irregularities in 2.1-channel subwoofer-satellite systems at listening positions, introducing a data-driven optimization approach that focuses on minimizing the maximum absolute group delay (max|GD|) in low frequency range. While subwoofers paired with satellite speakers are increasingly employed for low-frequency reproduction, the role of phase-related effects, such as group delay (GD), in contributing to FR inconsistencies like amplitude dips has received limited attention in prior research. Experiments were carried out in two different rooms, with FR and GD analyzed over a crossover frequency range of 40–140 Hz. The findings suggest that minimizing max|GD| could reduce FR irregularities, with results from a Fixed Effects model indicating a statistically significant positive relationship between max|GD| and ΔGD-SPL (coefficient: 22.274, p-value < 0.0001). An optimization algorithm is proposed to identify a crossover frequency that minimizes max|GD|, offering a phase-focused approach that may enhance low-frequency reproduction for practical applications like studio monitoring and home audio.

Hassanpour Guilvaiee Hamideh, Mousavi Abbas, Berggren Martin et al.

Sonic black holes (SBHs) are waveguides intended to slow down the wave propagation speed and focus the energy towards the end of the device. However, the extent to which these effects occur, as well as the degree of wave dispersion introduced, has not been systematically quantified. This article investigates these aspects through transient finite-element computations, analyzing the properties of a novel, numerically optimized SBH with enhanced wave-focusing capabilities. The investigation utilizes the lossless acoustic wave equation as well as a linearized compressible flow formulation to account for viscothermal losses. We analyze the wave focusing and filtering properties of the SBH by monitoring the pressure amplitude and the transmission and reflection coefficients. Moreover, we examine the effective wave propagation speed along the centerline of SBH and assess the similarity of pressure wave packets using cross-correlations. Our results reveal that the optimized SBH not only enhances wave focusing but also on average effectively slows down wave propagation, demonstrating the device's potential as a true sonic black hole. By investigating two crucial aspects – wave-slowing effect and signal dispersion – that were not previously explored, we provide a deeper understanding of the device's functionality and operational mechanisms, including how its design influences wave-focusing performance and local wave speed.

Mohammed Latif Siddiq, Arvin Islam-Gomes, Natalie Sekerak et al.

Reproducibility is a cornerstone of scientific progress, yet its state in large language model (LLM)-based software engineering (SE) research remains poorly understood. This paper presents the first large-scale, empirical study of reproducibility practices in LLM-for-SE research. We systematically mined and analyzed 640 papers published between 2017 and 2025 across premier software engineering, machine learning, and natural language processing venues, extracting structured metadata from publications, repositories, and documentation. Guided by four research questions, we examine (i) the prevalence of reproducibility smells, (ii) how reproducibility has evolved over time, (iii) whether artifact evaluation badges reliably reflect reproducibility quality, and (iv) how publication venues influence transparency practices. Using a taxonomy of seven smell categories: Code and Execution, Data, Documentation, Environment and Tooling, Versioning, Model, and Access and Legal, we manually annotated all papers and associated artifacts. Our analysis reveals persistent gaps in artifact availability, environment specification, versioning rigor, and documentation clarity, despite modest improvements in recent years and increased adoption of artifact evaluation processes at top SE venues. Notably, we find that badges often signal artifact presence but do not consistently guarantee execution fidelity or long-term reproducibility. Motivated by these findings, we provide actionable recommendations to mitigate reproducibility smells and introduce a Reproducibility Maturity Model (RMM) to move beyond binary artifact certification toward multi-dimensional, progressive evaluation of reproducibility rigor.

Carolyn Seaman, Rashina Hoda, Robert Feldt

The paper entitled "Qualitative Methods in Empirical Studies of Software Engineering" by Carolyn Seaman was published in TSE in 1999. It has been chosen as one of the most influential papers from the third decade of TSE's 50 years history. In this retrospective, the authors discuss the evolution of the use of qualitative methods in software engineering research, the impact it's had on research and practice, and reflections on what is coming and deserves attention.

Zhimin Zhao

Foundation models (FMs), particularly large language models (LLMs), have shown significant promise in various software engineering (SE) tasks, including code generation, debugging, and requirement refinement. Despite these advances, existing evaluation frameworks are insufficient for assessing model performance in iterative, context-rich workflows characteristic of SE activities. To address this limitation, we introduce \emph{SWE-Arena}, an interactive platform designed to evaluate FMs in SE tasks. SWE-Arena provides a transparent, open-source leaderboard, supports multi-round conversational workflows, and enables end-to-end model comparisons. The platform introduces novel metrics, including \emph{model consistency score} that measures the consistency of model outputs through self-play matches, and \emph{conversation efficiency index} that evaluates model performance while accounting for the number of interaction rounds required to reach conclusions. Moreover, SWE-Arena incorporates a new feature called \emph{RepoChat}, which automatically injects repository-related context (e.g., issues, commits, pull requests) into the conversation, further aligning evaluations with real-world development processes. This paper outlines the design and capabilities of SWE-Arena, emphasizing its potential to advance the evaluation and practical application of FMs in software engineering.

Gao Cong, Hu Chuandeng, Hou Bo et al.

To attenuate low-frequency noise in square ventilation ducts, a tunable duct silencer consisting of composite Helmholtz resonators (HR) that precisely controlled by a step motor was proposed in this paper. An analytical model based on temporal coupled mode theory (TCMT) is applied to explain the sound absorption mechanism. The design breaks the limitation that the operating frequency of a silencer is fixed after manufacturing and avoids the degradation of ventilation conditions by attaching to the duct as a side branch. By using a step motor to drive the tunable cavity HR, the silencer can achieve accurate and continuous adjustment of the operating frequency over the entire operating frequency spectrum. In the experiment, the silencer has an absorption bandwidth of 250 Hz and ranges from 710 Hz to 960 Hz. Porous material is inserted into the cavities of HR to improve the damping properties. When integrated into the simulation model, it enables the rapid design of silencer dimensions for different sound absorption frequencies. The design demonstrates a new solution for low frequency sound attenuation in ventilation ducts and provides a potential technique for the future development of active controlled duct silencers.

Rahier Gilles, Peyret Christophe

The article presents a fairly simple way to take solid bodies into account in acoustic radiation calculations using integral methods, while still using the free-space Green’s function. The approach is based on the Kirchhoff method and on a locally plane reflection assumption. It can be applied to both analytical noise sources and acoustic disturbances provided by numerical simulations, to fixed or mobile noise sources, concentrated or widely spread in a moving medium. The time-domain formulation is an important advantage for periodic signals rich in harmonics (rotors or propellers impulsive noise) and for broadband signals (profile or jet noise). The formulation and calculation algorithm are described in detail. The method’s accuracy and limitations are shown first by comparing the results with analytical solutions for the acoustic scattering of a point source by a sphere, for a fluid at rest. An application example is then given for a wing in a Mach 0.5 flow, and the results are compared with the numerical solution of the linearized Euler equations, in the presence of a mean flow. In addition, the article proposes expressions for direct calculation of the pressure gradient by Kirchhoff and Ffowcs Williams-Hawkings surface formulations.

Štorkán Jaroslav, Vampola Tomáš

The influence of the geometric configuration of the human vocal tract (HVT) on the character of acoustic energy distribution during phonation of the vowel [a:] has been analysed. The computationally efficient mathematic models of the HVT have been assembled based on super elements and an isoparametric element with higher degree of polynomial shape function. The assembled models enable the easy and quick geometrical reconfiguration of the HVT and they can be used for the time-consuming optimization process with aim to find the suitable geometric configuration of the HVT to generated the so-called singer’s formant.

Arandia-Krešić Srećko, Turalija Stipe, Alujević Neven et al.

This study focuses on the realisation of a small-scale inerter by relative acceleration feedback and its use to isolate vibration. Two accelerometers attached to the two mechanical terminals of an electrodynamic force actuator are used to obtain the relative acceleration signal. This signal is then amplified by a constant gain and fed back to the two electrical terminals of the electrodynamic actuator as a voltage command. This sensor-actuator system is coupled to a two Degree-Of-Freedom (DOF) mechanical oscillator to study the feedback loop’s stability and the maximum achievable inertance effect. A fully coupled simulation model including the dynamics of the two inertial accelerometers and the electrodynamic actuator is developed. It is shown that, because of the active control system emulating an inerter, an antiresonance appears in the transfer admittance function of the two DOF mechanical system. Therefore, significant vibration isolation effect can be achieved in the narrow frequency band around the antiresonance. The antiresonance frequency is easily tuned by adjusting the feedback gain. The synthetized inertance is a complex frequency dependent function, which is predominantly real-valued in the frequency range between 5 and 1600 Hz. It is shown that it does not depend on the mechanical system properties, but only on the properties of the transducers used and the signal conditioning in the feedback loop. As a result, this frequency range can be adjusted according to a particular application.

Nguyen Cong Truc, Li Dengke, Xiong Ziming et al.

Melamine foam, categorized as an open-cell foam structure, absorbs sound through its three-dimensional network of thin struts. The pore size polydispersity within the open-cell melamine microstructure is evidenced from a top-down approach and confirmed by scanning electron microscope (SEM)-image analysis. The remarkable ability of melamine foams to mitigate sound energy is attributed to the pore size distribution, which encompasses co-existing pores of distinct characteristic sizes. Consequently, low-frequency and high-frequency fluid flows will follow different paths within the pore structure. A poly-sized model, which provides a connection between microstructure polydispersity and macroscopic properties, is successfully applied to three different melamine foams. This work highlights the significance and implications of polydispersity effects on the acoustic behavior of open-cell foams.

Scholz Magdalena F., Brammer Anthony J., Marburg Steffen

An invertible, generalisable population model for the time course of the prevalence of a health effect resulting from habitual exposure to a physical agent, such as vibration, and noise, is proposed. The model includes a time-dependent factor representing the daily exposure, expfac(t), applied to a polynomial fit of prevalence-time data recorded in a population group and one additional numerical parameter, a'1, to adjust the model for exposure-specific conditions. A model is constructed for the prevalence of vibration-induced white finger (VWF) to confirm and validate its performance. A 4th-order polynomial fits representative data recorded in a population group from the commencement of exposure. Using the same polynomial coefficients and solely adjusting expfac(t) enables the model to fit period prevalence data for VWF from all available population groups as a function of time. Adjusting a'1 enables the model to predict the point prevalence. If expfac(t) is specified in terms of the daily 8-h, energy-equivalent, frequency-weighted triaxial acceleration, the prevalences observed in different populations groups can be interrelated and interpolated to a common value (e.g., 10%) by inverting the model. This will enable tolerable daily exposures suitable for occupational environments to be defined for hand-transmitted vibration.

Marx David, Margnat Florent, Bailliet Hélène et al.

Reflection of propagating modes is studied at the exit of a cylindrical acoustic wave guide from both an experimental and a numerical point of view. The plane mode and several purely azimuthal higher modes are extracted by means of modal decomposition and the uncoupled reflection coefficients of each mode are obtained using two microphonic antennas for Helmholtz numbers below 5.3. The reflection at the open end of the guide is studied for different guide terminations: without flange, with a finite flange, with an infinite rigid flange. A numerical model based on finite elements is set to mimic the experimental protocol: generation of the acoustic wave by a locally vibrating wall (to represent the flush-mounted loudspeakers used in the experiments), computation of the acoustic field in a cylindrical duct geometry and radiation in open space (represented by a half sphere). Results are also compared with the theoretical predictions from the literature when available. For the plane mode, the difference between the three sources of data is less than 5%; overall, the agreement allows to discern an effect of termination for the plane mode and for the first higher mode. An end with finite flange leads to intermediate behaviours between without flange and with an infinite flange only for the reflection coefficient of the plane mode.

Ausiello Ludovico, Ducceschi Michele, Duran Sebastian et al.

The variability in responses of acoustic instruments can be attributed to a combination of fluctuations in critical parameters of wood, such as density, stiffness, and strength, and design features such as body shapes or bracing geometries. Recent studies have successfully implemented the sine sweep method with small exciters to measure the acoustic response of guitars, yielding frequency responses with high coherence over a bandwidth reaching up to 8 kHz. This paper proposes validating a cost-effective measurement system which integrates electro-dynamic transducers and wide-band test signals (sine sweep and noise) against the traditional impact hammer method in the case of unbraced plates. Data from four actuators of different size and power will be presented together with a simple strategy to assess reliable and neutral excitation points, thanks to two complementary models which describe the interaction between exciter and plate. The paper will then showcase the applications of this measurement system in two scenarios. The first case study will focus on a cost-effective method for selecting acoustic wood, while the second will explore experimental real-time spectral analysis using pink noise. These case studies demonstrate the measurement system’s adaptability and immediacy, providing valuable insights for enhancing the design and performance of acoustic instruments.