检索结果-内蒙古大学图书馆

Exact and asymptotic solutions of wedge fields for sound propagation modeling using the physical theory of diffraction 46

Exact and asymptotic solutions of wedge fields for sound pro...

引用

46th International Congress and Exposition on Noise Control Engineering: Taming Noise and Moving Quiet, INTER-NOISE 2017

作者： Xiang, Ning Rozynova, Aleksandra Graduate Program in Architectural Acoustics Rensselaer Polytechnic Institute United States

Edge diffractions of sound propagation are relevant to predication of sound propagation over noise barrier, and objects in both urban environment and room-acoustic simulations. The need of developing accurate and cost-effective edge diffraction models has prompted recent investigations on edge diffractions with some progresses on solving multiple-order diffractions of finite wedges. This work explores an alternative approach based on the physical theory of diffraction (PTD). This approach is well suited for solving acoustic scattering problems from reflecting objects for noise prediction and room-simulation purposes. Some widely applied approaches based on the principle of geometrical acoustics are less suitable for geometrical shadow boundaries. The physical theory of diffraction emphasizes the physical principles. One of the important features of this physical acoustics (PA) approach is the ability to calculate the sound field more accurately inside shadow boundaries. This work exploits exact and asymptotic solutions of wedge fields based on the physical theory of diffraction. This paper will discuss implemented results of several canonical cases. © 2017 Institute of Noise Control Engineering. All rights reserved.

关键词： Diffraction

来源：评论

学校读者我要写书评

暂无评论

耦合空间的声学研究进展

引用

声学学报 2015年第2期40卷 331-337页

作者：向宁 Graduate Program in Architectural Acoustics Rensselaer Polytechnic Institute Troy New York

近年来由于混响室在演艺厅堂工程上的应用,唤发了对耦合空间声场研究的广泛兴趣。本文简短地回顾了马大猷先生对室内声学简正模态理论的贡献,对近代特别是最近15年来室内声学研究在耦合空间方面的发展,做了综述性讨论,包括简正模态分析... 详细信息

近年来由于混响室在演艺厅堂工程上的应用,唤发了对耦合空间声场研究的广泛兴趣。本文简短地回顾了马大猷先生对室内声学简正模态理论的贡献,对近代特别是最近15年来室内声学研究在耦合空间方面的发展,做了综述性讨论,包括简正模态分析和模态分解法、统计声学方法、几何声学方法、扩散方程、以及高分辨率实验技术和贝叶斯概率分析在耦合空间研究的应用。值马大猷先生诞辰一百周年之际,以此文缅怀德高望重的声学前辈。

关键词：室内声学几何声学扩散方程声学研究贝叶斯概率混响室模态分解大猷声场分布对耦合

来源：评论

学校读者我要写书评

暂无评论

Investigations of architectural configurations and acoustic parameters for multiple sources

Investigations of architectural configurations and acoustic ...

引用

20th International Congress on acoustics 2010, ICA 2010 - Incorporating the 2010 Annual Conference of the Australian Acoustical Society

作者： Robinson, Philip W. Xiang, Ning Braasch, Jonas Graduate Program of Architectural Acoustics Rensselaer Polytechnic Institute Troy NY United States

ISBN: (纸本)9781617827457

Much architectural acoustic research is devoted to a single source in a room. However, most situations involve competing sources. One context for understanding competition between multiple sources is operatic performance. Here, spectral and level differences between the singer on the stage and the orchestra in the pit, as reflected in the parameter Balance (B), allow the listener to discern both sources, but this is not a complete understanding of the situation. Human hearing is sensitive to more characteristics of the sound field than relative levels. Reflected sound, shaped by the acoustic enclosure, provides the auditory system information that can modify enjoyment and understanding of the signal. This research extends the single source room acoustic parameters Clarity (C), and Inter-aural cross-correlation(IACC) to multiple sound sources by examining their stage to pit ratios. In an opera house, there are specific surfaces which provide key early reflections to the audience from the singer, and separate surfaces that reflect sound from the orchestra. These surfaces can be manipulated separately in order to adjust the parameters of the singer's and orchestra's sound fields separately. This study utilizes acoustic modeling and subjective testing to investigate architectural and parametric configuration for listening to opera's multiple sources.

关键词： Acoustic fields

来源：评论

学校读者我要写书评

暂无评论

Bayesian design and fabrication framework for multilayered microperforated panel absorbers 46

Bayesian design and fabrication framework for multilayered m...

引用

46th International Congress and Exposition on Noise Control Engineering: Taming Noise and Moving Quiet, INTER-NOISE 2017

作者： Hou, Yiqiao Fackler, Cameron J. Xiang, Ning Graduate Program in Architectural Acoustics Rensselaer Polytechnic Institute TroyNY United States

Microperforated panel (MPP) sound absorbers are capable of providing high sound absorption coefficients without the use of fibrous materials. However, they typically function in limited frequency ranges. By combining multiple MPPs into a multilayer absorber system, the absorption bandwidth can be increased while maintaining high absorption coefficients. Each additional MPP layer added to such a multilayer absorber increases the overall complexity. Therefore, Bayesian model selection, which quantitatively embodies the principle of parsimony, is well-suited to the design of multilayer absorber systems to achieve a minimum number of layers. To demonstrate the Bayesian design framework, a practical multilayer absorber is designed. Based on this predicted design scheme, MPP samples are fabricated and used to conduct normal-incidence sound absorption measurements in an impedance tube. Fabrication uncertainties may lead to imprecise final absorption results, since each layer must accurately reflect four specific MPP parameters in order to match the desired design scheme. Therefore, quantifying fabrication uncertainty is of practical significance to satisfy application-specific requirements. In this work, Bayesian parameter estimation is used to infer the actual effective MPP parameters of the manufactured samples, from the experimentally measured absorption data. These results demonstrate that the design scheme can be well satisfied with Bayesian probabilistic inference. As a result, the MPP fabrication process is controlled by adjusting original design values to attain the ideal design scheme. © 2017 Institute of Noise Control Engineering. All rights reserved.

关键词： Fabrication

来源：评论

学校读者我要写书评

暂无评论

Model-based machine learning in acoustics applications from a Bayesian perspective 24

Model-based machine learning in acoustics applications from ...

引用

24th International Congress on acoustics, ICA 2022

作者： Xiang, Ning Chen, Ziqi Zhang, Jiahua Nolan, Mélanie Graduate Program in Architectural Acoustics Rensselaer Polytechnic Institute TroyNY United States

Recent acoustics investigations increasingly employ machine learning methods to analyze experimental data. Using well-understood models or hypotheses, acoustics analyses often embody two levels of inference: model selection and parameter estimation based on the chosen model. Model-based Bayesian analysis provides solutions of both inference levels centered around Bayes' theorem within a unified framework. The data-driven machine learning method represents a learning process from data in order to update our knowledge. This is exactly consistent with the core of Bayesian probability theory, which represents how our prior knowledge is updated in presence of the data. This paper discusses the model-based machine learning methods in a way of thinking like a Bayesian. In particular, it emphasizes that the well-understood models are considered as a part of the prior knowledge which are readily incorporated in the learning process. This paper highlights data-driven machine learning methods from a Bayesian perspective based on recent acoustics investigations, such as acoustic array signal processing, normal incident impedance tube measurements, chamber-based absorption measurements and wavenumber spectral analysis in enclosed spaces. Numerical challenges and promising solutions for two-levels of Bayesian learning are also discussed. © ICA *** rights reserved

关键词： Bayesian inference data-driven algorithms machine learning model-based analysis

来源：评论

学校读者我要写书评

暂无评论

Bayesian analysis for evaluation of interdependence between parameters of multilayer microperforated panel absorbers

Bayesian analysis for evaluation of interdependence between ...

引用

42nd International Congress and Exposition on Noise Control Engineering 2013: Noise Control for Quality of Life, INTER-NOISE 2013

作者： Xiang, Ning Schmitt, Andrew Fackler, Cameron Graduate Program in Architectural Acoustics Rensselaer Polytechnic Institute Troy NY United States

ISBN: (纸本)9781632662675

The Bayesian inference framework has recently been applied to a wide range of acoustics engineering problems. This paper demonstrates how two levels of inference -Bayesian model selection and parameter estimation - can be applied to the design of multilayer microperforated panel (MPP) absorbers. MPP absorbers are capable of producing high acoustic absorption coefficients without the use of fibrous porous materials, extending their potential use to many critical situations where traditional materials do not suffice. Combining several MPP layers can drastically increase the absorption bandwidth of an MPP absorber. When designing such multilayer MPP absorbers with the Bayesian inference framework, understanding the interdependence among the multi-layered MPP parameters is crucial. Occam's razor is embodied by the Bayesian framework, intrinsically producing a multilayer design which meets user-specified absorption requirements while minimizing the number of MPP layers used. In addition to the necessary number of MPP layers and corresponding parameter values, the Bayesian framework also provides quantitative measures of the interdependence between the MPP parameters across multilayer configurations. Focusing on the practical design of multilayer MPP absorbers, this paper discusses quantifying the interrelationship among the MPP parameters, obtaining estimates of their values, and minimizing the number of MPP layers required. Copyright© (2013) by Austrian Noise Abatement Association (OAL).

关键词： Multilayers

来源：评论

学校读者我要写书评

暂无评论

Near-field localization of sound sources using a spherical microphone array 24

Near-field localization of sound sources using a spherical m...

引用

24th International Congress on acoustics, ICA 2022

作者： Xiang, Ning Metzgen, Tommy Graduate Program in Architectural Acoustics Rensselaer Polytechnic Institute TroyNY United States

Spherical microphone arrays have been widely used in various acoustical applications, such as detection and localization of sound sources. In this work, the spherical harmonics theory supports formulations of parametric models for a spherical microphone array to localize sound sources. In the source presence, the parametric models are critical to localize an unknown number of multiple sound sources. This work applies two levels of Bayesian inference for enumeration and localization of potentially multiple sources. This work focuses on near-field localization of sound sources. Upon a positive detection, Bayesian model selection and parameter estimation are carried out within a unified framework to localize near-field sound sources including source distances and direction-of-arrivals. This paper discusses model formulations, uncertainties of localization parameters using preliminary experimental data. © 2022 Proceedings of the International Congress on acoustics. All rights reserved.

关键词： Spheres

来源：评论

学校读者我要写书评

暂无评论

Diffusion equation modelling for energy flow analysis in reverberation chambers 50

Diffusion equation modelling for energy flow analysis in rev...

引用

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

作者： Hao, Ryan Xiang, Ning Graduate Program in Architectural Acoustics Rensselaer Polytechnic Institute TroyNY12180 United States

ISBN: (纸本)9781732598652

Noise is a growing concern in the built environment. Sound absorbers are a viable option for noise treatments. However, their characterization of absorption coefficient in standardized chambers still show challenges for high accuracy as required in practice. In recent years, experimental analysis has shown that assumptions of diffuse sound fields made in well-known reverberation chamber are unfulfilled [1]. Specifically, where sound intensities in chamber-based measurement methods are presumed to be isotropic, or diffuse. Diffusion equation models (DEM) have shown dramatic changes in energy flow in the presence of highly absorptive materials under test. This has been attributed to well-documented inconsistencies reported from reverberation chamber measurements across different laboratories. This work will demonstrate that the DEM is proving to be a computationally efficient and viable method for predicting sound energy flows, garnering an increasing amount of interest from the acoustical community. © INTER-NOISE 2021 .All right reserved.

关键词： Reverberation

来源：评论

学校读者我要写书评

暂无评论

Measuring the uniform diffusion coefficient: Synthesized aperture goniometer measurements

Measuring the uniform diffusion coefficient: Synthesized ape...

引用

157th Meeting Acoustical Society of America 2009

作者： Robinson, Philip Xiang, Ning Antonio, Peter D. Graduate Program in Architectural Acoustics Rensselaer Polytechnic Institute Troy NY 12180 United States

There are currently two methods to measure the diffusion / scattering from acoustical surfaces: reverberation chamber measurement and in-situ measurement using a semicircular array of microphones called a goniometer. Each of these methods has advantages and drawbacks. The reverberation chamber method accounts for random incidence, but produces inconsistent results for materials of the same profile but different absorption. It does not distinguish between one-dimensional and two-dimensional surface topologies, since the sample is rotated, and is also inapplicable to high absorption materials. The goniometer measurement quantifies directivity as well as diffusion, but presents challenges related to processing power, as many microphones are required to achieve reasonable resolution. Using a procedure akin to synthesized aperture radar, a 2.5 deg. resolution polar plot of the 180 deg. response is achieved by scanning eight microphones rather than employing a full array of 72. Also, since the direct sound and reflected sound arrive at the receiver in close succession when measuring low incident angles, special processing must be exercised in order to resolve the relationship between the sounds. This research addresses the challenges of the goniometer measurement and attempts to use a synthesized aperture goniometer to derive accurate diffusion and directivity properties of materials. © 2009 Acoustical Society of America.

关键词： Microphones

来源：评论

学校读者我要写书评

暂无评论

Sound absorber design of multilayered microperforated panels using Bayesian inference 47

Sound absorber design of multilayered microperforated panels...

引用

47th International Congress and Exposition on Noise Control Engineering: Impact of Noise Control Engineering, INTER-NOISE 2018

作者： Xiang, Ning Fackler, Cameron J. Hou, Yiqiao Graduate Program in Architectural Acoustics Rensselaer Polytechnic Institute TroyNY12180 United States

Noise control engineering often requires broadband sound absorbers with high absorption coefficients. Additionally, in some applications, traditional fibrous materials may be restrictive for use. Microperforated panel (MPP) sound absorbers are a potential solution meeting non-fibrous, hygienic requirements. Although they typically possess limited absorption bandwidth, the absorption bandwidth may be increased by combining multiple MPPs into a multilayer system while maintaining high absorption. In addition to increasing the overall absorption bandwidth, each additional MPP layer also increases the number of design parameters by four. Therefore, Bayesian model selection, quantitatively implementing the principle of parsimony, represents a well-suited method for the design of multilayer absorber systems which penalizes overlayered configurations. This work designs a practical multilayer absorber to demonstrate the Bayesian design framework involving two levels of probabilistic inference, namely Bayesian model selection and parameter estimation. To experimentally validate the Bayesian design, manufactured MPP samples are measured in an impedance tube. This paper discusses the Bayesian design formulation, efficient implementation of two levels of Bayesian inference, and experimental validation for a multilayered microperforated panel absorber. © INTER-NOISE 2018 - 47th International Congress and Exposition on Noise Control Engineering: Impact of Noise Control Engineering. All rights reserved.

关键词： Bandwidth

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：