Michael Vorlnder
Hasil untuk "Acoustics in engineering. Acoustical engineering"
Menampilkan 20 dari ~6450534 hasil · dari CrossRef, DOAJ, arXiv, Semantic Scholar
Diego Firmenich, Leandro Antonelli, Bruno Pazos et al.
User stories are one of the most widely used artifacts in the software industry to define functional requirements. In parallel, the use of high-fidelity mockups facilitates end-user participation in defining their needs. In this work, we explore how combining these techniques with large language models (LLMs) enables agile and automated generation of user stories from mockups. To this end, we present a case study that analyzes the ability of LLMs to extract user stories from high-fidelity mockups, both with and without the inclusion of a glossary of the Language Extended Lexicon (LEL) in the prompts. Our results demonstrate that incorporating the LEL significantly enhances the accuracy and suitability of the generated user stories. This approach represents a step forward in the integration of AI into requirements engineering, with the potential to improve communication between users and developers.
Yong Deng, Adrian Paskert, Zhiyuan Zhang et al.
As a next-generation toolkit, microrobots can transform a wide range of fields, including micromanufacturing, electronics, microfluidics, tissue engineering, and medicine. While still in their infancy, acoustically actuated microrobots are becoming increasingly attractive. However, the interaction of acoustics with microstructure geometry is poorly understood, and its study is necessary for developing next-generation acoustically powered microrobots. We present an acoustically driven helical microrobot with a length of 350 μm and a diameter of 100 μm that is capable of locomotion using a fin-like double-helix microstructure. This microrobot responds to sound stimuli at ~12 to 19 kHz and mimics the spiral motion of natural microswimmers such as spirochetes. The asymmetric double helix interacts with the incident acoustic field, inducing a propulsion torque that causes the microrobot to rotate around its long axis. Moreover, our microrobot has the unique feature of its directionality being switchable by simply tuning the acoustic frequency. We demonstrate this locomotion in 2D and 3D artificial vasculatures using a single sound source.
Stefan Fichna, Steven van de Par, Bernhard U. Seeber et al.
Virtual acoustic environments enable the creation and simulation of realistic and eco-logically valid daily-life situations vital for hearing research and audiology. Reverberant indoor environments are particularly important. For real-time applications, room acous-tics simulation requires simplifications, however, the necessary acoustic level of detail (ALOD) remains unclear in order to capture all perceptually relevant effects. This study examines the impact of varying ALOD in simulations of three real environments: a living room with a coupled kitchen, a pub, and an underground station. ALOD was varied by generating different numbers of image sources for early reflections, or by excluding geo-metrical room details specific for each environment. Simulations were perceptually eval-uated using headphones in comparison to binaural room impulse responses measured with a dummy head in the corresponding real environments, or by using loudspeakers. The study assessed the perceived overall difference for a pulse stimulus, a played electric bass and a speech token. Additionally, plausibility, speech intelligibility, and externaliza-tion were evaluated. Results indicate that a strong reduction in ALOD is feasible while maintaining similar plausibility, speech intelligibility, and externalization as with dummy head recordings. The number and accuracy of early reflections appear less relevant, pro-vided diffuse late reverberation is appropriately represented.
Yinchu Wang, Liang Dong, Runze Zhou et al.
The vortex shedding and shock generated inside the pump used in nuclear power plants during operation lead to energy loss and efficiency reduction, and the noise induced by the flow affects the system’s safety and reliability. The groove-type geometry of shark skin surface has features such as low hydraulic drag coefficient and low turbulence noise and has been widely applied in energy engineering. This study adopted computational fluid dynamics (CFD) and computational aerodynamic acoustics (CAA) methods to research the effects of Space-V-groove and V-groove bionic impellers on hydraulic performance and acoustic characteristics. In addition, the impacts of both bionic groove geometries on the external characteristics, wall shear stress, blade surface velocity, and vortex core distribution were compared and analyzed. The results found that Space-V-groove can effectively improve hydraulic performance. At the rated flow rate, the drag reduction rates of Space-V-groove and V-groove pumps are 2.86% and 1.82%, while the total sound pressure level is reduced by 1.36% and 1.2%, respectively. The Space-V-groove geometry is more effective in destroying the shedding vortex and trailing vortex, thereby modifying the turbulence in the impeller flow path and reducing energy loss and noise.
Yang Hu, Zhiwang Zhang, Ying Cheng et al.
The acoustic router, capable of guiding sound waves along specific paths, holds a significant value in both science and engineering. Compared to traditional methods of implementing acoustic routing, the recently developed concept of topological acoustics, with its nontrivial topological phases, offers the potential to achieve a robust acoustic routing device. However, current investigations primarily focus on individual topological phases within a single bandgap, thereby limiting the exploration of diverse topological phases in multiple bandgaps and their hybridizations. In this study, we utilize topological acoustics to construct a robust dual-band acoustic router, which is challenging to achieve with traditional acoustics. By calculating Chern and valley topological phases in different bands, we reveal the competitive relations between different topological phases in a specific bandgap. Furthermore, by modifying the boundary meta-atoms, we have increased the operational frequency bands and proposed a triple-band acoustic router.
Jishen Zhu
Piezoelectric acoustic transducers enable the mutual conversion between mechanical energy and electrical energy. In recent years, piezoelectric transducers, as efficient and reliable sustainable energy harvesting devices, have demonstrated unique application value in various disciplines such as physics, acoustics, and engineering. This paper comprehensively reviews the current research status and future development directions of acoustic transducers. Firstly, the physical mechanism of the piezoelectric effect is thoroughly analyzed, and the basic operating mode of piezoelectric acoustic transducers is systematically explained. Furthermore, the characteristics and design directions of different types of piezoelectric materials are comprehensively reviewed, with a focus on exploring material innovation approaches to enhance performance. Moreover, various design methods, including layered, integrated, and curved structures, are summarized with emphasis on their crucial roles in improving sensitivity and adaptability. Techniques improving performance were also reviewed. Given the unique nature of piezoelectric effect, the research outlines applications of transducers in sonar systems, structural monitoring systems, and micro-piezoelectric systems. Through the above review, this paper provides profound insights into the research on piezoelectric acoustic transducers, emphasizing in-depth investigations in specific areas. It offers researchers from backgrounds including materials science, acoustics, and electronics different directions, ideas, and methods, thereby promoting innovation in wireless, sensing, and energy fields.
R. Anaghraj, M. K, R. Mini
Low-frequency broadband sound absorption with minimal dimensions and material cost is an ongoing research challenge in engineering acoustics. Common acoustic structures, such as microperforated panels (MPPs) and porous structures, are ineffective in alleviating low-frequency noise. In this context, a sound-absorbing panel consisting of two axially coiled-up tubes and MPP is proposed for effective low-frequency noise abatement. Initially, an electro-acoustic analogy-based analytical approach is developed to predict the acoustic absorption performance of series and parallel configurations of MPP and coiled-up tubes, and the findings are corroborated by full-field finite element simulations. The parametric analyses revealed that, by carefully choosing the geometric features of the coiled-up tubes, the absorption spectra of each tube can be coupled with that of MPP, and thus the bandwidth of absorption can be broadened. Furthermore, it is observed that the parallel configuration of MPP and coiled-up tubes significantly lowered the thickness of the absorber without affecting the absorption bandwidth. Importantly, the parallel configuration of MPP and coupled tubes demonstrated more than 80% absorption in the frequency range of 250 to 350 Hz.
P. Agrawal, Shengyang Zhuang, S. Dreher et al.
Advancements in additive manufacturing in composites have transformed various fields in aerospace, medical devices, tissue engineering, and electronics, enabling fine-tuning material properties by reinforcing internal particles and adjusting their type, orientation, and volume fraction. This capability opens new possibilities for tailoring materials to specific applications and optimizing the performance of 3D-printed objects. Existing reinforcement strategies are restricted to pattern types, alignment areas, and particle characteristics. Alternatively, acoustics provide versatility by controlling particles independent of their size, geometry, and charge and can create intricate pattern formations. Despite the potential of acoustics in most 3D printing, limitation arises from the scattering of the acoustic field between the polymerized hard layers and the unpolymerized resin, leading to undesirable patterning formation. However, this challenge can be addressed by adopting a novel approach that involves simultaneous reinforcement and printing the entire structure. Here, we present SonoPrint, an acoustically-assisted volumetric 3D printer that produces mechanically tunable composite geometries by patterning reinforcement microparticles within the fabricated structure. SonoPrint creates a standing wave field that produces a targeted particle motif in the photosensitive resin while simultaneously printing the object in just a few minutes. We have also demonstrated various patterning configurations such as lines, radial lines, circles, rhombuses, quadrilaterals, and hexagons using microscopic particles such as glass, metal, and polystyrene particles. Furthermore, we fabricated diverse composites using different resins, achieving 87 microns feature size. We have shown that the printed structure with patterned microparticles increased their tensile and compression strength by ∼38% and ∼75%, respectively.
Ting-Wei Liu, C. Chan, R. Wu
In engineering acoustics, the propagation of elastic flexural waves in plate and shell structures is a common transmission path of vibrations and structure-borne noises. Phononic metamaterials with a frequency band gap can effectively block elastic waves in certain frequency ranges, but often require a tedious trial-and-error design process. In recent years, deep neural networks (DNNs) have shown competence in solving various inverse problems. This study proposes a deep-learning-based workflow for phononic plate metamaterial design. The Mindlin plate formulation was used to expedite the forward calculations, and the neural network was trained for inverse design. We showed that, with only 360 sets of data for training and testing, the neural network attained a 2% error in achieving the target band gap, by optimizing five design parameters. The designed metamaterial plate showed a −1 dB/mm omnidirectional attenuation for flexural waves around 3 kHz.
Utkarsh R. Patel, Yiqian Mao, Eric Michielssen
The Wigner-Smith (WS) time delay matrix relates a lossless system's scattering matrix to its frequency derivative. First proposed in the realm of quantum mechanics to characterize time delays experienced by particles during a collision, this article extends the use of WS time delay techniques to acoustic scattering problems governed by the Helmholtz equation. Expression for the entries of the WS time delay matrix involving renormalized volume integrals of energy densities are derived, and shown to hold true independent of the scatterer's geometry, boundary condition (sound-soft or sound-hard), and excitation. Numerical examples show that the eigenmodes of the WS time delay matrix describe distinct scattering phenomena characterized by well-defined time delays.
Zeinab Abou Khalil, Stefano Zacchiroli
Background: Software development results in the production of various types of artifacts: source code, version control system metadata, bug reports, mailing list conversations, test data, etc. Empirical software engineering (ESE) has thrived mining those artifacts to uncover the inner workings of software development and improve its practices. But which artifacts are studied in the field is a moving target, which we study empirically in this paper.Aims: We quantitatively characterize the most frequently mined and co-mined software artifacts in ESE research and the research purposes they support.Method: We conduct a meta-analysis of artifact mining studies published in 11 top conferences in ESE, for a total of 9621 papers. We use natural language processing (NLP) techniques to characterize the types of software artifacts that are most often mined and their evolution over a 16-year period (2004-2020). We analyze the combinations of artifact types that are most often mined together, as well as the relationship between study purposes and mined artifacts.Results: We find that: (1) mining happens in the vast majority of analyzed papers, (2) source code and test data are the most mined artifacts, (3) there is an increasing interest in mining novel artifacts, together with source code, (4) researchers are most interested in the evaluation of software systems and use all possible empirical signals to support that goal.
Utkarsh R. Patel, Yiqian Mao, Jack Hamel et al.
The Wigner-Smith (WS) time delay matrix relates an acoustic system's scattering matrix to its wavenumber derivative. The entries of the WS time delay matrix can be expressed in terms of energy density-like volume integrals, which cannot be efficiently evaluated in a boundary element method framework. This paper presents two schemes for efficiently populating the WS time delay matrix. The direct formulation casts the energy density-like volume integrals into integrals of the incident field and the field and/or its normal derivative over the scatterer surface. The indirect formulation computes the system's scattering matrix and its wavenumber derivative, again via surface integration, and then invokes the WS relationship to compute the WS time delay matrix. Both the direct and the indirect formulations yield equivalent results and can be easily integrated into standard boundary element codes.
Rédha Bendoumia
Guangyuan Huang, K. Seid, Zhigang Yang et al.
Purpose For flow around elongated bluff bodies, flow separations would occur over both leading and trailing edges. Interactions between these two separations can be established through acoustic perturbation. In this paper, the flow and the acoustic fields of a D-shaped bluff body (length-to-height ratio L/H = 3.64) are investigated at height-based Reynolds number Re = 23,000 by experimental and numerical methods. The purpose of this paper is to study the acoustic feedback in the interaction of these two separated flows. Design/methodology/approach The flow field is measured by particle image velocimetry, hotwire velocimetry and surface oil flow visualization. The acoustic field is modeled in two dimensions by direct aeroacoustic simulation, which solves the compressible Navier–Stokes equations. The simulation is validated against the experimental results. Findings Separations occur at both the leading and the trailing edges. The leading-edge separation point and the reattaching flow oscillate in accordance with the trailing-edge vortex shedding. Significant pressure waves are generated at the trailing edge by the vortex shedding rather than the leading-edge vortices. Pressure-based cross-correlation analysis is conducted to clarify the effect of the pressure waves on the leading-edge flow structures. Practical implications The understanding of interactions of separated flows over elongated bluff bodies helps to predict aerodynamic drag, structural vibration and noise in engineering applications, such as the aerodynamics of buildings, bridges and road vehicles. Originality/value This paper clarifies the influence of acoustic perturbations in the interaction of separated flows over a D-shaped bluff body. The contribution of the leading- and the trailing-edge vortex in generating acoustic perturbations is investigated as well.
Thang Tran, Feruza Amirkulova, Ehsan Khatami
Acoustic metamaterials are engineered microstructures with special mechanical and acoustic properties enabling exotic effects such as wave steering, focusing and cloaking. The design of acoustic cloaks using scattering cancellation has traditionally involved the optimization of metamaterial structure based on direct computer simulations of the total scattering cross section (TSCS) for a large number of configurations. Here, we work with sets of cylindrical objects confined in a region of space and use machine learning methods to streamline the design of 2D configurations of scatterers with minimal TSCS demonstrating cloaking effect at discrete sets of wavenumbers. After establishing that artificial neural networks are capable of learning the TSCS based on the location of cylinders, we develop an inverse design algorithm, combining variational autoencoders and the Gaussian process, for predicting optimal arrangements of scatterers given the TSCS. We show results for up to eight cylinders and discuss the efficiency and other advantages of the machine learning approach.
A. S. Dzurak, J. Epps, A. Laucht et al.
Quantum technology is exploding. Computing, communication, and sensing are just a few areas likely to see breakthroughs in the next few years. Worldwide, national governments, industries, and universities are moving to create a new class of workforce - the Quantum Engineers. Demand for such engineers is predicted to be in the tens of thousands within a five-year timescale. However, how best to train this next generation of engineers is far from obvious. Quantum mechanics - long a pillar of traditional physics undergraduate degrees - must now be merged with traditional engineering offerings. This paper discusses the history, development, and first year of operation of the world's first undergraduate degree in quantum engineering. The main purpose of the paper is to inform the wider debate, now being held by many institutions worldwide, on how best to formally educate the Quantum Engineer.
Rebekka Wohlrab, David Garlan
[Context and motivation:] For realistic self-adaptive systems, multiple quality attributes need to be considered and traded off against each other. These quality attributes are commonly encoded in a utility function, for instance, a weighted sum of relevant objectives. [Question/problem:] The research agenda for requirements engineering for self-adaptive systems has raised the need for decision-making techniques that consider the trade-offs and priorities of multiple objectives. Human stakeholders need to be engaged in the decision-making process so that the relative importance of each objective can be correctly elicited. [Principal ideas/results:] This research preview paper presents a method that supports multiple stakeholders in prioritizing relevant quality attributes, negotiating priorities to reach an agreement, and giving input to define utility functions for self-adaptive systems. [Contribution:] The proposed method constitutes a lightweight solution for utility function definition. It can be applied by practitioners and researchers who aim to develop self-adaptive systems that meet stakeholders' requirements. We present details of our plan to study the application of our method using a case study.
Jie Luo
Bilal Raza, Stephen G. MacDonell, Tony Clear
This study presents an analysis of the most recent literature addressing global software engineering (GSE). We examine the current state of GSE research using a new Systematic Snapshot Mapping (SSM) technique. We analysed 275 papers published between January 2011 and June 2012 in peer-reviewed conferences, journals and workshops. Our results provide a coarse-grained overview of the very recent literature addressing GSE, by classifying studies into predefined categories. We also follow and extend several prior classifications to support our synthesis of the data. Our results reveal that currently GSE studies are focused on Management and Infrastructure related factors. Most of the studies are conducted at the organizational level using methods such as interviews, surveys, field studies and case studies. We use inter-country network analysis to confirm that the USA and India are major players in GSE, with USA-India collaborations being the most frequently studied, followed by USA-China. Specific groups of countries have dominated the reported GSE project locations. In contrast, regions including Central Asia, South Asia (except India), Africa and South East Asia have not been covered in these studies. While a considerable number of GSE-related studies have been published they are currently quite narrowly focused on exploratory research and explanatory theories. The critical research paradigm has been untouched, perhaps due to a lack of criteria and principles for carrying out such research in GSE. An absence of formulative research, experimentation and simulation, and a comparative focus on evaluative approaches, all suggest that existing tools, methods and approaches from related fields are being tested in the GSE context. However, these solutions may not scale to cover GSE-related issues or may overlook factors/facets specific to GSE.
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