Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 49 for “"Sound transmission"”.
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Sound transmission through lined ducts in parallel.
Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1979.
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Control of Sound Transmission with Active-Passive Tiles
Nowadays, numerous applications of active sound transmission control require lightweight partitions with high transmission loss over a broad frequency range and simple control strategies. In this work an active-passive sound transmission control approach is investigated that potentially addresses …
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Structure-borne sound transmission within electric power steering systems
… todetermine the contributions of structure-borne sound sources to receiver responses at target positions.The classical TPA approach is based on contact forces at the interface between sourceand receiver to characterise the dynamic loads induced by the source and frequency responsefunctions (FRFs) …
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Sound transmission loss characteristics of three layer composite wall constructions
Thesis. 1975. Ph.D.--Massachusetts Institute of Technology. Dept. of Mechanical Engineering.
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An investigation of sound transmission irregularity in a one dimensional enclosure
Thesis: B.S., Massachusetts Institute of Technology, Department of Physics, 1949
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Active control of sound transmission through plates in a reverberant environment
Active control of sound transmission through an elastic plate placed between two reverberation chambers is studied experimentally. Active acoustic control is performed using piezoelectric sensors and actuators bonded to the plate. The control technique uses an adaptive control algorithm. Results …
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Near-Field Pressure Distributions to Enhance Sound Transmission into Multi-Layer Materials
… also plays a role in preventing acoustic transmission, as the wave speed difference between air and solid materials results in an increase of the resulting propagation angles, creating near-field pressure distributions in the solid material. By utilizing evanescent pressure distributions, …
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Sound Transmission Loss Between Spaces Connected by Multiple Paths: A Newmeasurement Technique
Made available in DSpace on 2014-12-10T19:06:53Z (GMT). No. of bitstreams: 1 7212372.pdf: 3257018 bytes, checksum: b726831fca5d5a6c2d72b9322a8936ab (MD5) Previous issue date: 1971
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Active control of sound transmission/radiation from elastic plates using multiple piezoelectric actuators
… a theoretical analysis of active control of sound radiation from elastic plates with the use of piezoelectric transducers as actuators. A strain-energy model (SEM), based upon the conservation of strain energy, for a laminate beam with attached or embedded finite-length spatially distributed …
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Smart double panel with decentralised active damping units for the control of sound transmission
… is formulated and a parametric study of passive sound transmission is performed using the mathematical model. In Chapter three the performance of decentralised feedback control systems using absolute and relative velocity is analysed theoretically. In Chapter four the stability and performance of …
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Implications to underwater sound transmission of inhomogeneities in the mixed layer of the ocean
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Meteorology, 1962.
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Effects of tympanic-membrane perforations on middle-ear sound transmission : measurements, mechanisms, and models
Thesis (Ph. D.)--Massachusetts Institute of Technology, Whitaker College of Health Sciences and Technology, 1998.
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Control of sound transmission into payload fairings using distributed vibration absorbers and Helmholtz resonators
A new passive treatment to reduce sound transmission into payload fairing at low frequency is investigated. This new solution is composed of optimally damped vibration absorbers (DVA) and optimally damped Helmholtz resonators (HR). A fully coupled structural-acoustic model of a composite cylinder …
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In-situ measurement methods for characterisation and diagnosis of airborne sound transmission through multi-layered building partitions
… for characterisation and diagnosis of airborne sound transmission through building partitions. Using standard tests, the airborne sound insulation of partitions can be measured as the Sound Reduction Index ‘SRI’. While the SRI provides the frequency dependence of sound insulation (or …
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Identification of sound transmission paths within a hermetic reciprocating refrigeration compressor via multiple-input/single-output modeling
… (MISO) modeling, the propagation paths of sound within a reciprocating refrigeration compressor have been investigated and ranked. By investigating the nature of sound propagation within reciprocating compressors, it is hoped that compressor manufacturers can effectively formulate …
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MODELING AND DESIGN OF A SMART DOUBLE-PANEL SYSTEM FOR THE CONTROL OF SOUND TRANSMISSION INTO AIRCRAFT CABIN
… used in the design of trim panels and additional sound absorption materials are also used in fuselage structures. However, this improvement in interior noise reductions is limited to mid-range and high-range frequencies (above about 1000 Hz). In fact, double-panel sidewall systems currently used …
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Determination of Backup Alarm Masked Threshold in Construction Noise
Sound transmission devices have advanced filtering abilities that theoretically protect the ear from harmful Masking noise while amplifying the sounds that need to be heard, such as backup alarms. Therefore, such devices should provide improved signal detection in noise when compared to their …
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Decentralised velocity feedback control for thin homogeneous and lightweight sandwich panels
… to weight ratio but also exhibit undesirable sound transmission properties which could cause problems with vehicle interior noise. The aim of this work is to assess the performance of decentralised velocity feedback control on lightweight sandwich panels.<br/>The first part of this thesis …
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