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American Gear Manufacturers Association 2022 Fall Technical Meeting, FTM 2022

作者： Wagner, Matthew Mark, William D. Isaacson, Aaron Applied Research Laboratory Pennsylvania State University United States Applied Research Laboratory Graduate Program in Acoustics Pennsylvania State University United States

ISBN: (纸本)9781713862246

The ability to detect the onset of a gear system failure via accelerometer measurements is of interest in a research environment as well as in gear systems deployed in the field. The goal in either case is to detect a failure as early as possible while simultaneously minimizing the risk of false shutdowns. The accelerometer based gear health monitoring system described herein was developed for use in a laboratory setting for monitoring power recirculating gear tests. In this environment it is desirable to detect the early onset of failures so the primary failure mode as well as the time to failure can be accurately determined. Minimizing false shutdowns is also critical to maximizing rig uptime and testing efficiency. The signal processing algorithm uses even-angle resampling along with time synchronous averaging to minimize the influence of vibration sources other than the gear mesh. In the case of hunting tooth ratio gearsets it is shown that it is possible to completely separate the damage response of each gear in the pair from a single accelerometer signal using these techniques. The average log ratio (ALR) algorithm is then employed to monitor the time synchronous averaged signals for the onset of damage. A summary of these signal processing concepts is given, along with an overview of system hardware, signal processing workflow, and sample data. Copyright ©2022.

关键词： Accelerometers

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Photoacoustic measurement of the optical absorption of aerosols 182

Photoacoustic measurement of the optical absorption of aeros...

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182nd Meeting of the Acoustical Society of America, ASA 2022

作者： Case, John Arthur Smith, Robert W. Graduate Program in Acoustics The Pennsylvania State University University ParkPA16802 United States Applied Research Laboratory The Pennsylvania State University State CollegePA16801 United States

Atmospheric optical absorption, including the contribution from aerosols, is important in modeling propagation of laser beams and for climate research. Photoacoustic methods have been used in the past for this purpose, as they directly measure absorption, rather than the sum of absorption and scattering. Acoustic operating frequency determines the sensed aerosol size range. The design of a windowless double-Helmholtz photoacoustic aerosol sensing system, operating at an acoustic frequency near 150 Hz, with the capability to measure an optical absorption with a 1/e length of 1 Mm, will be presented. In this design, environmental noise limits the instrument sensitivity. To improve immunity to environmental noise with an open resonator, an aluminum acoustic enclosure was built around the system, with welded vacuum flanges for inputs and outputs. Inlet and outlet acoustic mufflers were designed to limit the in-band noise entering the measurement system. A modulated 10 W 1064 nm fiber laser was used as the excitation source, and a high-sensitivity microphone placed within the open-cell cavity was used to measure the internal photoacoustic pressure fluctuations. The system was modeled using various computational tools, including MATlab, Simulink, and ANSYS, and then was constructed and tested. lab measurement results will be presented. © 2022 Acoustical Society of America.

关键词： Light absorption

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Learning-Based Tone Mapping to Improve 3D SAS ATR

Learning-Based Tone Mapping to Improve 3D SAS ATR

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IEEE International Symposium on Geoscience and Remote Sensing (IGARSS)

作者： Gregory D. Vetaw Benjamin Cowen Daniel C. Brown David P. Williams Suren Jayasuriya School of Electrical Computer and Energy Engineering Arizona State University The Applied Research Laboratory Graduate Program in Acoustics Pennsylvania State University

Automatic target recognition (ATR) for 3D synthetic aperture sonar (SAS) imagery is an intrinsic challenge in highly cluttered ocean environments, especially for objects partially or completely buried in the sediment. Conventional dynamic range compression (DRC) techniques such as log-compression, which is a type of tone mapping intended to appeal to the human visual system, can further obscure the sonar signatures of these already physically occluded objects and lead to suboptimal downstream ATR performance, particularly for convolutional neural networks (CNNs). In this paper, we present a novel machine learning-based approach for tone mapping sub-bottom SAS imagery as a pre-processing stage in the 3D SAS ATR pipeline. This learned tone mapping function can be jointly optimized with a CNN-based ATR algorithm. We train and validate our method on measured volumetric SAS data captured by the Sediment Volume Search Sonar (SVSS) system.

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基于合成磁场的声学非互易

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Science Bulletin 2023年第19期68卷 2164-2169,M0003页

作者：陈召宪李正伟翁经锴梁彬陆延青程建春 Andrea Alù Collaborative Innovation Center of Advanced Microstructures Key Laboratory of Modern Acoustics of Ministry of EducationInstitute of AcousticsDepartment of PhysicsNanjing UniversityNanjing 210093China College of Engineering and Applied Sciences Nanjing UniversityNanjing 210093China Photonics Initiative Advanced Science Research CenterCity University of New YorkNew York NY 10031USA Physics Program Graduate CenterCity University of New YorkNew York NY 10016USA

通过设计特定的时空调制,合成磁性的概念最近被提出以实现对光子和声子等电荷中性粒子的非互易操控,但现有方案存在着隔离度低、信号频率变化等问题.本文设计了一种新型耦合共振腔系统,其中动态耦合的相位作为实现声学合成磁场的新机制... 详细信息

通过设计特定的时空调制,合成磁性的概念最近被提出以实现对光子和声子等电荷中性粒子的非互易操控,但现有方案存在着隔离度低、信号频率变化等问题.本文设计了一种新型耦合共振腔系统,其中动态耦合的相位作为实现声学合成磁场的新机制并打破了系统的时间反演对称性,最终取得了优异的声波非互易传输.基于旋转波近似方法,作者严格推导出了实现系统强非互易声传输的参数条件.通过优化动态耦合之间的相位差以及耦合强度,实验展示了隔离度达45-dB和正向传输率达0.85的优异单向声传输.此外,这种单向声传输具有始末态频率不变和隔离方向可电控等重要特性.该研究突破了现有声波单向操控机制在效率和隔离度方面的局限,并为实现弗洛奎和非线性声学拓扑绝缘体提供了新途径.

关键词：隔离度信号频率动态耦合非线性声学拓扑绝缘体耦合共振耦合强度声传输

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Design, Fabrication, and Testing of Stiffened Composite Panels with Acoustically Tailored Stiffeners 79

Design, Fabrication, and Testing of Stiffened Composite Pane...

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79th Vertical Flight Society Annual Forum and Technology Display, FORUM 2023

作者： Brown, Avery Moorhouse, Anna M. Bakis, Charles E. Smith, Edward C. Beck, Ben S. Shepherd, Micah R. Engineering Science and Mechanics Dept. Pennsylvania State Univ. University ParkPA United States Graduate Program in Acoustics Pennsylvania State Univ. University ParkPA United States Aerospace Engineering Dept. Pennsylvania State Univ. University ParkPA United States Engineering Acoustics Dept. Applied Research Laboratory State CollegePA United States Physics and Astronomy Dept. Brigham Young Univ. ProvoUT United States

ISBN: (纸本)9781713874799

Carbon fiber reinforced epoxy composites are being increasingly used for load bearing structural elements in large transport rotorcraft. However, due to the increased stiffness-to-density ratio of composites, problems associated with vibration and interior noise can be exacerbated by the use of composites in airframes. The current investigation explores the potential of optimized composite meta-structures to reduce vibration and interior noise in rotorcraft. The approach involves designing a taper into the thickness of blade stiffeners which, when combined with a limited amount of absorbing material in the thinned region, creates what is known as an "acoustic black hole" (ABH) in the stiffener. It is hypothesized that optimally designed ABH stiffeners can reduce broadband vibrations in stiffened panels. An optimization routine has been developed to determine the tradeoffs between vibration, mass, and buckling load due to compression parallel to the stiffeners. The tradeoffs are visualized using a 3-D Pareto front that helps the designer decide on the optimal design. Carbon/epoxy panels were made using vacuum-bag-oven processing with out-of-autoclave prepreg and verified to be of good quality. Panel vibration, buckling onset, and post-buckling load-deflection behavior were simulated using finite elements and measured using model testing and compression testing. Based on preliminary results, ABH-tapered stiffened panels have the ability to reduce radiated noise without a significant penalty in the mass and compressive load-bearing capability. Copyright © 2023 by the Vertical Flight Society. All rights reserved.

关键词： Optimal systems

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Design optimization and performance comparison of three styles of one-dimensional acoustic black hole vibration absorbers

Design optimization and performance comparison of three styl...

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作者： McCormick, Cameron A. Shepherd, Micah R. Graduate Program in Acoustics/Applied Research Lab The Pennsylvania State University University Park PA16802 United States

Structures whose thickness is tapered according to a power law exhibit the ‘acoustic black hole’ (ABH) effect, which can be leveraged for effective vibration reduction without a net increase in weight. However, classic ABH theory is not explicit about the precise topology of the taper, which may have significant practical effects in structures containing ABHs. In this paper, three styles of one-dimensional ABH vibration absorbers are examined, referred to herein as ‘standard symmetric’, ‘standard nonsymmetric’, and ‘double-leaf’. Each style of ABH is embedded in a beam and a multi-objective approach is used to identify the set of ABH designs that optimally minimize the beam's vibration response and its overall mass. Comparison of the results show that each style of ABH has a similar trade-off between the two objectives, but that the choice of style – particularly as regards the application of added damping – can have significant effects on overall performance. © 2019 Elsevier Ltd

关键词： Economic and social effects

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Quantifying sound transmission of building structures for optimization in early-stage design 50

Quantifying sound transmission of building structures for op...

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50th International Congress and Exposition of Noise Control Engineering, INTER-NOISE 2021

作者： Broyles, Jonathan M. Shepherd, Micah R. Brown, Nathan C. Department of Architectural Engineering Pennsylvania State University 104 Engineering Unit A University ParkPA United States Applied Research Laboratory Graduate Program in Acoustics Pennsylvania State University 201 Applied Science Building University ParkPA United States

ISBN: (纸本)9781732598652

Technological advancements in computational building modeling have enabled designers to conduct simulations at the component level. With the evolution of parametric modeling, designers can evaluate multiple design options and identify the best performing solutions before expending resources on physical testing and eventual construction. However, to conduct design space exploration or optimization, an objective function is necessary to evaluate performance. While defined objectives exist for design goals such as sustainability, energy usage, structural performance, and daylighting, there does not yet exist an encompassing objective that can accurately quantify the sound transmission of structures in building design. This paper proposes four transmission rating strategies that can describe air-borne and impact performance of floors, walls, or other acoustic barriers. The approaches consider air-borne and structure-borne sound for four floor constructions, revealing strengths and weaknesses across the methods. Implementation of the approaches in an optimization framework is discussed, along with practical methods for optimizing the objectives in early-stage design. © INTER-NOISE 2021 .All right reserved.

关键词： Floors

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A 3D GAN Architecture for Volumetric Synthetic Aperture Sonar

A 3D GAN Architecture for Volumetric Synthetic Aperture Sona...

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OCEANS

作者： Greg D. Vetaw Albert Reed Daniel C. Brown Suren Jayasuriya School of Electrical Computer and Energy Engineering Arizona State University The Applied Research Laboratory Graduate Program in Acoustics Pennsylvania State University

ISBN: (纸本)9781665427883

Synthetic aperture sonar (SAS) is used extensively in underwater imaging for visualizing the seafloor and objects present on it. However, processing SAS images can be time-consuming and tedious, with machine learning techniques being ineffective due to the lack of available data. In particular, automated target recognition (ATR) with 3D SAS data for machine learning is challenging in many ways due to the complexity with working with 3D volumetric data. Recently, researchers have introduced generative adversarial networks (GANs) to help perform 2D SAS image generation for data augmentation. Following this line of work in this paper, we introduce a 3D-GAN architecture to generate photorealistic 3D SAS data which matches the fidelity of real data. In particular, we discuss novel latent space sampling and normalization to help 3D GANs overcome mode collapse for generating volumetric SAS information. Experimental results are shown on real 3D SAS data, showing the potential of using 3D GANs for dataset augmentation in the future.

关键词： Three-dimensional displays Target recognition Image synthesis Sea floor Imaging Data visualization Machine learning

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Indirect Calibration of Hyperspectral Images Using Rock Samples

Indirect Calibration of Hyperspectral Images Using Rock Samp...

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Workshop on Hyperspectral Image and Signal Processing: Evolution in Remote Sensing, WHISPERS

作者： Daniel C. Zanotta Leonardo D. Araújo Marcelo K. De Souza Delano M. Ibanez Luiz G. Silveira Maurício R. Veronez Vizlab — X-Reality and GeoInformatics Lab UNISINOS São Leopoldo RS Brazil Graduate Program in Applied Computing at Vale do Rio dos Sinos University São Leopoldo RS Brazil PETROBRAS - Petrobras Research and Development Center (CENPES) RJ Brazil

ISBN: (数字)9798331513139

ISBN: (纸本)9798331513146

This paper presents a methodology for the indirect calibration of hyperspectral images using radiometric measurements from field samples. While hyperspectral imaging (HSI) is essential in remote sensing, its accuracy depends on precise calibration, which is often challenging in the field. Most approaches rely on a single standard panel used as absolute reference and the empirical line method. This often leads to mistakes and uncertainties in the analysis. In this paper we propose an alternative that utilizes radiometric data from rock samples with known spectral properties to indirectly calibrate hyperspectral images. The results show specific improvements in accuracy, particularly in the shape of the curves, compared to standard calibration method. The calibrated images offer better material differentiation and more reliable spectral signatures, which are crucial for geological mapping and mineral exploration. This approach can enhance the reliability of hyperspectral data analysis in geological and environmental studies, especially in situations where time and logistics are challenging.

关键词： Accuracy Uncertainty Coal Signal processing Rocks Radiometry Calibration Minerals Standards Hyperspectral imaging

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Mineralogical Classification of Sedimentary Rocks by Spectral Matching Techniques Based on Library and Field-Work References

Mineralogical Classification of Sedimentary Rocks by Spectra...

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Workshop on Hyperspectral Image and Signal Processing: Evolution in Remote Sensing, WHISPERS

作者： Daniel C. Zanotta Lais V. De Souza Marcelo K. De Souza Alysson S. Ayres Vinícius F. Sales Graciela R. Racolte Delano M. Ibanez Luiz G. Silveira Maurício R. Veronez Vizlab — X-Reality and GeoInformatics Lab UNISINOS São Leopoldo RS Brazil Graduate Program in Applied Computing at Vale do Rio dos Sinos University São Leopoldo RS Brazil PETROBRAS - Petrobras Research and Development Center (CENPES) RJ Brazil

ISBN: (数字)9798331513139

ISBN: (纸本)9798331513146

Sedimentary rocks are of great importance for the oil and gas industry. Spectral matching using known references made on hyperspectral images is one of the most rapid and cost effective alternatives for the detailed analysis in these areas, since they can adequately catch the specific absorption features of the multiple minerals available. In many initiatives, scientists run the methods with standard spectral references, usually from spectral libraries or samples from other places. However, for the success of their application, they must be used along with spectral references that accurately describe the actual constituents of the surface. In this paper we scrutinize three different ways for mineralogical mapping performed by spectral matching techniques. The results showed that using reference spectra from samples collected directly on the surveyed environment can considerably improve the results, reaching high scores, pointing out that many places share common substances, but each specific material has particular differences that cannot be generalized.

关键词： Costs Systematics Signal processing Rocks Gas industry Libraries Minerals Petroleum industry Standards Hyperspectral imaging

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