1,720,987 research outputs found
Numerical model of the sound field inside cars for the creation of virtual audible reconstructions
No full textThe research undertaken aims to the development of a new numerical predictive technique, capable of producing such a detailed simulation, so that it can be used for the creation of “virtual” sound samples, theoretically indistinguishable from binaural recordings inside a real car. This way, a proposed (not existing yet) sound system could be compared with the existing ones by direct listening tests.
This paper describes the implementation of the numerical model, based on Boundary Elements for low frequencies and Pyramid Tracing for higher frequencies. The results of the two models are merged together, producing a binaural impulse response which can be convolved with the music signal. The performances of the system were evaluated by listening tests, in comparison with experimental measurements taken in a 1:5 scale model of a car compartment
Subjective comparison between Stereo Dipole and 3D Ambisonics surround systems for automotive applications
No full textA Sensible Technique to Detect Mollicutes Impurities in Human Cells Cultured in GMP Condition
No full textIn therapeutic trials the use of manipulated cell cultures for clinical applications is often required. Mollicutes microorganism contamination of tissue cultures is a major problem because it can determine various and severe alterations in cellular function. Thus methods able to detect and trace cell cultures with Mollicutes contamination are needed in the monitoring of cells grown under good manufacturing practice conditions, and cell lines in continuous culture must be tested at regular intervals. We here describe a multiplex quantitative polymerase chain reaction assay able to detect contaminant Mollicutes species in a single-tube reaction through analysis of 16S–23S rRNA intergenic spacer regions and Tuf and P1 cytoadhesin genes. The method shows a sensitivity, specificity, and robustness comparable with the culture and the indicator cell culture as required by the European Pharmacopoeia guidelines and was validated following International Conference on Harmonization guidelines and Food and Drug Administration requirements
IPA - A Subjective Assessment Method of Sound Quality of Car Sound Systems
Full text linkThe paper describes a new subjective evaluation method of the acoustical quality produced by a sound system inside a car compartment. The method produces a single rating number, called IPA (Index of Performance Acoustic), defined as a weighted average of the subjective responses to a questionnaire, being compiled during listening tests conducted with the subject seating inside different cars.
The paper describes the details of the subjective test, and focuses on the choice of questions in the questionnaire and of the weight to be employed. The principal innovation of the new method is the fact that the weights are changed according to the reliability of the subject (which is also inferred from the questionnaires), and thus the evaluation is very robust and almost immune from the inclusion in the panel of completely unreliable evaluators
Inverse numerical filters for linearisation of loudspeaker's response
No full textIn this paper a non-linear loudspeaker model, which accurately reproduces the low frequency behavior, is presented. This description, derived from an extension of the well known Small-Thiele equations, requires far less computational time and memory space than generic non linear structures. Moreover a noticeable further reduction of the number of operations and of the memory cells required has been achieved by means of a multirate architecture. Inversion of the proposed model allows digital prefiltering of the electrical signal in order to compensate for the nonidealities of the electro-acoustic conversion. The above filter structure implemented on a digital signal processor, placed between the audio signal source and the power amplifier allows effective compensation of loudspeaker linear (both magnitude and phase) and non-linear distortion. Measurement results obtained with a commercial woofer are discussed
Non-linear Digital Audio Processor for dedicated loudspeaker systems
No full textIn this paper a non-linear loudspeaker
model, which accurately reproduces the low frequency
behavior, is presented. This description, derived from
an extension of the well known Small-Thiele equations,
requires far less computational time and memory space
than generic non linear structures. Moreover a noticeable
further reduction of the number of operations and of
the memory cells required has been achieved by means
of a multirate architecture. Inversion of the proposed
model allows digital prefiltering of the electrical signal in
order to compensate for the non idealities of the electroacoustic
conversion. The above filter structure implemented
on a digital signal processor, placed between the
audio signal source and the power amplifier allows effective
compensation of loudspeaker linear (both magnitude
and phase) and non linear distortion. Measurement
results obtained with a commercial woofer are discussed
Comparative analysis of NK-cell receptor expression and function across primate species: Perspective on antiviral defenses
No full text
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