Abstract
Computational study of world music outliers reveals countries with distinct recordings
Botswana is the country with the most distinct musical recordings around the world while China has the most distinct recordings in relation to its neighbours, according to research by Queen Mary University of London.
The study, published in PLOS ONE, demonstrates the first time computational tools have been used to compare world music cultures at a large scale. In particular, the researchers aimed to identify recordings that have outstanding musical characteristics – referred to as ‘outliers’.
The researchers also explored geographical patterns of music outliers for different sets of features and found that Benin has the most outlier recordings with respect to rhythm and harmony, French Guiana with respect to timbre and Zimbabwe with respect to melody.
For more information: https://www.sciencedaily.com/releases/2017/12/171221122551.htm
Cochlear implants for people with severe to profound deafness
Cochlear implants have been available in the United Kingdom for over 20 years and are the only successful treatment available for people with severe to profound deafness. They can transform lives by restoring an individual’s ability to hear and understand speech or help a deaf person hear for the first time. Pioneering research into the devices at the Institute of Sound and Vibration Research (ISVR) has improved their performance and led to changes in health policy by the UK’s National Institute for Health and Clinical Excellence (NICE).
For more information: https://www.southampton.ac.uk/engineering/research/impact/cochlear_implants_for_people_with_severe_to_profound_deafness.page
Overlapping signal separation method using superresolution technique based on experimental echo shape
Overlapping signals separation is a difficult problem, where time windowing is unable to separate signals overlapping in time, and frequency domain filtering is unable to separate signals with overlapping spectra. In this work, a simulation under MATLAB is implemented to illustrate the concept of overlapping signals. We propose an approach for resolving overlapping signals based on Fourier transform and inverse Fourier transform. The proposed approach is tested under MATLAB, and the simulation results validate the effectiveness and the accuracy of the proposed approach. The approach is developed using Gerchberg superresolution technique to cope with signals with low signal-to-noise ratio. For practical work, an echo shape determination is required to apply the proposed technique. The experimental results show accurate localization of multiple targets.
For more information: https://www.hindawi.com/journals/aav/2017/7132038/
Vibration monitoring for defect diagnosis on a machine tool: a comprehensive case study
The application of vibration monitoring and analysis was carried out on a lathe. The characteristic frequencies of tapered roller bearings, gear mesh frequencies and belt drive frequencies were found to locate the source of vibration. Multi-harmonics of fundamental defect frequencies were observed. From the real-time observation, experimental prediction of defects has been found to be correct and accurate. This case study shows that vibration analysis plays a vital role in monitoring the condition of the machine tool.
For more information: https://www.iiav.org/ijav/index.php?va=viewpage&vaid=177&id_number=73
Investigations on wave propagation of the pressure pulsation in a Helmholtz-type hydraulic silencer with a hemispherical vessel
The Helmholtz-type hydraulic silencer is one of the most practical silencers for attenuating pressure pulsations in hydraulic systems owing to its simple structure and reasonable cost. Maximum attenuation performance can be attained at the resonance frequency in accordance with the principle of Helmholtz resonance. Therefore, it is extremely important to precisely determine the resonance frequency at the design stage. It was clarified in our previous study that the shape of the volume vessel affects the resonance frequency of the silencer because of the wave propagation of pressure pulsation inside the volume vessel. In this study, the attenuation characteristics and wave propagation in a silencer with a hemispherical vessel are investigated. A mathematical model that takes into account the propagation of a one-dimensional wave in the radial direction of the hemispherical vessel is proposed and compared with the step section approximation model and the classic lumped parameter model. Furthermore, the effectiveness of the theoretical analysis is verified by experiments, wherein the dimensional specifications of the vessel and neck are adjusted.
For more information: http://vibrationacoustics.asmedigitalcollection.asme.org/article.aspx?articleID=2551858
Acoustics, ultrasound and vibration research
NMI is responsible for maintaining and disseminating Australia’s standards for acoustics (sound power level, sound pressure level and sound intensity level), vibration (acceleration and velocity) and ultrasound (ultrasound power).
NMI undertakes research and development activities as part of its charter to continually improve the Australian standards. This includes development of novel measurement techniques to assist in the measurement of air- and structure-borne sound and vibration, and development and implementation of equipment to provide the highest possible accuracy in a calibration facility. The dissemination of measurement standards and supply of research assistance to Australian industry for the measurement of sound and vibration are also undertaken.
NMI participates in numerous international technical committees to give Australian representation in such bodies as International Organization for Standardization (ISO) and International Electrotechnical Commission (IEC), and supply training and support to the measurement institutes of a number of other countries.
For more information: http://www.measurement.gov.au/ScienceTechnology/Pages/Acoustics,UltrasoundandVibrationResearch.aspx
Structural reliability, monitoring and uncertainty
Uncertainty and variability of mechanical systems are issues of increasing concern, both in the design phase and in operational conditions. Vibrations are often the cause of non-nominal behaviour or, in some cases, even structural degradation.
Our research group develops numerical formalisms and algorithms to deal with non-determinism in analysis and design. After a decade of intensive research on non-probabilistic methods, a fuzzy finite element method is now available for use in conjunction with commercial finite element (FE) software. In the area of probabilistic methods, we have validated an inverse identification strategy to quantify scatter in structural model parameters that use both experimental data sets and numerical FE models. Recent efforts focus on the identification of spatial scatter and uncertainty using interval fields and random fields.
For more information: https://www.mech.kuleuven.be/en/research/mod/research-areas
Smart system dynamics
The smart system dynamics research focuses on the development, implementation/realization and experimental validation of innovative mechatronic concepts that aim at improving the performance of dynamic systems with respect to vibrations, noise emission, safety, throughput often in a trade-off with energy efficiency. This research combines the development of smart systems for specific applications and their experimental validation and industrial implementation, with the development of design, analysis and modelling methodologies and supporting theoretical contributions.
For more information: https://www.mech.kuleuven.be/en/research/mod/research-areas