A New Voltage-Tunable Light Deflector by Use of Off-Axis Acoustic Domain in CdS Crystals

1972 ◽  
Author(s):  
Seijiro FURUKAWA ◽  
George MOTOSUGI
Keyword(s):  
Acoustic Domain

Finite Elements with Nonreflecting Boundary Conditions Formulated by the Helmholtz Integral Equation

1999 ◽  
Vol 121 (2) ◽  
pp. 214-220
Author(s):  
Shu-Wei Wu
Keyword(s):  
Integral Equation ◽  
Finite Elements ◽  
Surrounding Medium ◽  
Constraint Equation ◽  
Thin Body ◽  
Source Surface ◽  
Element Formulation ◽  
Artificial Boundary ◽  
Acoustic Domain ◽  
Helmholtz Integral

In the proposed approach, an acoustic domain is split into two parts by an arbitrary artificial boundary. The surrounding medium around the vibrating surface is discretized with finite elements up to the artificial boundary. The constraint equation specified on the artificial boundary is formulated with the Helmholtz integral equation straightforwardly, in which the source surface coincides with the vibrating surface discretized with boundary elements. To ensure the uniqueness of the numerical solution, the composite Helmholtz integral equation proposed by Burton and Miller was adopted. Due to the avoidance of singularity problems inherent in the boundary element formulation, this method is very efficient and easy to implement in an isoparametric element environment. It should be noted that the present method also can be applied to thin-body problems by using quarter-point elements.

scholarly journals Secure Audio-Visual Data Exchange for Android In-Vehicle Ecosystems

2021 ◽  
Vol 11 (19) ◽  
pp. 9276
Author(s):  
Alfred Anistoroaei ◽  
Adriana Berdich ◽  
Patricia Iosif ◽  
Bogdan Groza
Keyword(s):  
Data Exchange ◽  
Key Exchange ◽  
Visual Data ◽  
Security Applications ◽  
Diffie Hellman ◽  
Audio Data ◽  
Diffie Hellman Key Exchange ◽  
Visual Domain ◽  
Audio Video ◽  
Acoustic Domain

Mobile device pairing inside vehicles is a ubiquitous task which requires easy to use and secure solutions. In this work we exploit the audio-video domain for pairing devices inside vehicles. In principle, we rely on the widely used elliptical curve version of the Diffie-Hellman key-exchange protocol and extract the session keys from the acoustic domain as well as from the visual domain by using the head unit display. The need for merging the audio-visual domains first stems from the fact that in-vehicle head units generally do not have a camera so they cannot use visual data from smartphones, however, they are equipped with microphones and can use them to collect audio data. Acoustic channels are less reliable as they are more prone to errors due to environmental noise. However, this noise can be also exploited in a positive way to extract secure seeds from the environment and audio channels are harder to intercept from the outside. On the other hand, visual channels are more reliable but can be more easily spotted by outsiders, so they are more vulnerable for security applications. Fortunately, mixing these two types of channels results in a solution that is both more reliable and secure for performing a key exchange.

Estimation of Error in Acoustic Analysis

1994 ◽  
Author(s):  
Ravi P. Tetambe ◽  
C. Rajakumar
Keyword(s):  
Pressure Distribution ◽  
Stress Analysis ◽  
Error Estimation ◽  
Acoustic Analysis ◽  
Frequency Domain Analysis ◽  
Error Estimator ◽  
Estimation Of Error ◽  
Acoustical Analysis ◽  
Acoustic Cavities ◽  
Acoustic Domain

Abstract Application of error estimation in acoustical analysis is shown. Based on the Zienkiewicz-Zhu1 error estimator for stress analysis, a procedure for predicting the error in pressure distribution computed from a frequency domain analysis of acoustic cavities is outlined. Examples are presented to illustrate the usefulness of the error estimator in adaptively meshing the acoustic domain to minimize the error at different excitation frequencies.

Active Noise Control for Hearing Screening Test

2010 ◽  
Vol 1 (3) ◽  
pp. 67-78
Author(s):  
Dhifaf Azeez ◽  
Mohd Alauddin Mohd Ali ◽  
Hafizah Husain ◽  
Gan Kok Beng ◽  
Cila Umat
Keyword(s):  
Screening Test ◽  
Ambient Noise ◽  
Noise Control ◽  
Sampling Rate ◽  
Active Noise Control ◽  
Hearing Screening ◽  
Labview Software ◽  
Active Noise ◽  
Human Ear ◽  
Acoustic Domain

A hearing screening test is a method to determine human ear disorders and conventional audiometers and audiologists are required to perform the test. However, this procedure is difficult to implement, especially in a remote site such as a factory or a school due to the ambient noise that may cause test inaccuracy. In this work, the application of active noise control (ANC) is proposed to reduce the ambient noise using a personal computer in a hearing screening test. The ANC algorithm was simulated in MATLAB software and implemented using a computer with data acquisition modules and LabVIEW software. Results show that anti-noise was successfully generated in the electrical domain but no reduction was observed in the acoustic domain. ANC is a deterministic application that requires a real-time operating system to respond to the input with precisely timed output. To have an effective ANC system, the processing time has to be less than 0.125 ms at 8 KHz sampling rate.

scholarly journals Analysis and Application of Screens for Acoustic Impedance in a Speaker Box with a Passive Radiator to Decrease Standing-Wave Influence

2020 ◽  
Vol 10 (3) ◽  
pp. 866
Author(s):  
Yuan-Wu Jiang ◽  
Dan-Ping Xu ◽  
Zhi-Xiong Jiang ◽  
Jun-Hyung Kim ◽  
Ki-Hong Park ◽  
...  
Keyword(s):  
Standing Wave ◽  
Acoustic Resonance ◽  
Experimental Result ◽  
Parameter Method ◽  
Analysis Tool ◽  
Analysis Method ◽  
The Finite Element Method ◽  
Lumped Parameter ◽  
Acoustic Domain ◽  
Lumped Parameter Method

Micro speakers are playing an increasingly important role with the development of multimedia devices. This study applies the lumped-parameter method, which uses an equivalent circuit to model the electromagnetic and mechanical domains. The acoustic domain is modeled using the finite element method. Based on the analysis tool, the use of a screen is analyzed, and the screen is designed to depress the acoustic resonance in the sound-pressure-level curve and improve the performance. The samples are fabricated, and the experiment verifies the analysis method. The experimental result shows that the peak and dip due to the standing wave are cancelled, and the frequency response is smooth when the screen is used.

Subsonic acoustic domain in GaAs

1969 ◽  
Vol 7 (1) ◽  
pp. 129-133 ◽  
Author(s):  
M. Schulz ◽  
B.K. Ridley
Keyword(s):  
Acoustic Domain

Frequency Spectrum of Acoustic Domain Caused by Variable Rise-Time Pulse

1981 ◽  
Vol 20 (S3) ◽  
pp. 265 ◽  
Author(s):  
Yoshiaki Tokunaga ◽  
Tomonobu Hata ◽  
Toshio Hada
Keyword(s):  
Frequency Spectrum ◽  
Rise Time ◽  
Acoustic Domain ◽  
Time Pulse

Auditory-Visual Perception of Speech with Reduced Optical Clarity

1979 ◽  
Vol 22 (2) ◽  
pp. 212-223 ◽  
Author(s):  
Norman P. Erber
Keyword(s):  
Auditory Perception ◽  
Hearing Impaired ◽  
Auditory Training ◽  
Optical Distortion ◽  
Acoustic Cues ◽  
Sensation Level ◽  
Training Technique ◽  
Children Speech ◽  
Acoustic Domain ◽  
Impaired Children

Optical cues for visual and auditory-visual (A-V) perception of speech were varied by placing a sheet of rough-surfaced Plexiglas between talker and lipreader and systematically changing the distance between Plexiglas and talker. This distorts the optical environment in a way that is analogous to masking or filtering in the acoustic domain. In studies with normal-hearing adults and with hearing-impaired children, speech (words, sentences) was presented live under different degrees of optical distortion, and observers attempted to identify the stimuli. Visual-alone (lipreading) scores dropped abruptly to the chance level as Plexiglas distance (blurring) was increased. A-V scores were relatively high for clear conditions but diminished gradually as Plexiglas distance (blurring) was increased. Under extremely poor optical conditions, A-V scores reached a plateau. This represents essentially auditory perception without meaningful optical cues for speech. Results parallel those of previous acoustic studies that compared auditory with A-V perception of speech as a function of S/N ratio or sensation level, demonstrating a reciprocal aspect of optical and acoustic cues for speech perception. Optical distortion seems to have potential as an auditory training technique to shift attention of hearing-impaired observers to non-dominant acoustic cues during A-V perception of speech.

scholarly journals Reading fluency and statistical learning across modalities and domains: online and offline measures

2021 ◽  
Author(s):  
Ágnes Lukács ◽  
Dorottya Dobó ◽  
Ágnes Szőllősi ◽  
Németh Kornél ◽  
Krisztina Sára Lukics
Keyword(s):  
Statistical Learning ◽  
Reading Fluency ◽  
Reading Difficulties ◽  
Reaction Times ◽  
Choice Task ◽  
Learning Abilities ◽  
Forced Choice Task ◽  
Learning Impairment ◽  
Acoustic Domain ◽  
Different Levels

The vulnerability of statistical learning has been demonstrated in reading difficulties in both the visual and acoustic domains. We examined segmentation abilities of adolescents with three different levels of reading fluency in the acoustic verbal and visual nonverbal domains. We applied online target detection tasks, where the extent of learning is reflected in differences between reaction times to predictable versus unpredictable targets. Explicit judgments of well-formedness were also elicited in an offline two-alternative forced choice task. A significant online learning effect was observed in all groups in both domains, and online patterns were similar in participants with low, medium and high reading fluency. On the offline measures, all groups were at chance in the visual, but not the verbal domain. These findings suggest that there is no robust statistical learning impairment associated with reading problems either in the visual or the acoustic domain in adolescents. Results also imply that offline measures may mask learning abilities, and measuring learning online can provide a deeper understanding of the learning process and of its potential deficits.

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