Euclidean Algorithm for Sound Generation

Euclidean algorithm is known by humanity for more than two thousand years. During this period many applications for it were found, covering different disciplines and music is one of those. Such algorithm application in music first appeared in 2005 when researchers found a correlation between world music rhythm and the Euclidean algorithm result, defining Euclidean rhythms as the concept.In the modern world, music could be created using many approaches. The first one being the simple analogue, the analogue signal is just a sound wave that emitted due to vibration of a certain medium, the one that is being recorded onto a computer hard drive or other digital storage called digital and has methods of digital signal processing applied. Having the ability to convert the analogue signal or create and modulate digital sounds creates a lot of possibilities for sound design and production, where sonic characteristics were never accessible because of limitations in sound development by the analogue devices or instruments, nowadays become true. Sound generation process, which usually consists of modulating waveform and frequency and can be influenced by many factors like oscillation, FX pipeline and so on. The programs that influence synthesised or recorded signal called VST plugins and they are utilising the concepts of digital signal processing.This paper aims to research the possible application of Euclidean rhythms and integrate those in the sound generation process by creating a VST plugin that oscillates incoming signal with one of the four basic wave shapes in order to achieve unique sonic qualities. The varying function allows modulation with one out of four basic wave shapes such as sine, triangle, square and sawtooth, depending on the value received from the Euclidean rhythm generator, switching modulating functions introduces subharmonics, with the resulting richer and tighter sound which could be seen on the spectrograms provided in the publication.

Towards a traceable divider for composite voltage waveforms below 1 kV

In the framework of the European Project 19NRM07 HV-com2 supporting the standardization in high-voltage testing with composite and combined wave shapes, a divider to employ in a test set-up for validation of electrical devices submitted to composite voltages below 1 kV has been developed at the Istituto Nazionale di Ricerca Metrologica (INRIM) and currently is under extensive testing. After a simulation stage, an available divider has been modified to comply with the IEC 60,060 requirements in terms of step response and scale factor. To be suitably fast in replying to step voltages, an adjustment of the components of the low-voltage arm has been made. The divider has been calibrated with traceability to the relevant INRIM National Standards and characterized exploiting its scale factor at different voltages and frequencies. The divider has been then inserted in a set-up with a sinusoidal generator, an impulse generator and coupling–blocking elements to carry out tests at low voltages (below 1 kV) with single voltages. In these tests, the divider showed a satisfactory attitude as converting device and its scale factor is traceable with suitable uncertainty.

A Low-Cost Modular Image-Based Approach to Characterize Large-Field Wave Shapes in Glass Wave Flume

Accurately determining water surface elevation and wave shapes in the hydraulic laboratory is critical for experimental research and physical understanding of ocean waves. Existing technologies such as wave gauges cannot capture the continuous wave profile across both space and time. This poses an issue, as nonlinear wave characteristics vary as a function of position and cannot be fully described using such point measurements. Furthermore, wave gauges are intrusive to the flow field. Alternative single-camera methods can’t capture wave characteristics in a large field-of-view properly without sacrificing resolution. In this paper, the authors propose an easy-to-use, low-cost method for measuring wave height and shape along the length of the flume over time. The method utilizes stitching of multiple web-cameras and the application of a Canny-based edge detection algorithm with experimentally determined thresholds and additional filters for maximum robustness and efficacy. Additionally, distortion correction is implemented in a computationally efficient manner. Video is acquired by three Logitech C920 PRO HD cameras recording at a resolution of 1280 × 720 at 24fps. The wave generator can generate waves with frequency between 0.1Hz and 1Hz. The experimental results show that wave height measurements can be obtained with a maximum resolution of 0.83mm with a relative error of ±1.5% when compared with a reference wave gauge measurement. This work demonstrates the ability to arbitrarily extend the horizontal field-of-view while providing more accurate measurement results.

Influence of Tsunami Aspect Ratio on Near and Far-Field Tsunami Amplitude

This study presents a numerical investigation of the source aspect ratio (AR) influence on tsunami decay characteristics with an emphasis in near and far-field differences for two initial wave shapes Pure Positive Wave and N-wave. It is shown that, when initial total energy for both tsunami types is kept the same, short-rupture tsunami with more concentrated energy are likely to be more destructive in the near-field, whereas long rupture tsunami are more dangerous in the far-field. The more elongated the source is, the stronger the directivity and the slower the amplitude decays in the intermediate- and far-fields. We present evidence of this behavior by comparing amplitude decay rates from idealized sources and showing their correlation with that observed in recent historical events of similar AR.

A multivibrator and oscillator trainer kit for an emerging pedagogy in engineering

Implementation of a complex circuit with hardware components in a conventional way seems to be quite difficult for the students. Resultant wave-shapes may not be accurate and determined values of different parameters may not be exact. Due to inaccurate outcomes and time-consuming process in a conventional way, researchers despond to continue their approach. In this paper, a trainer kit has been developed which is just like a laboratory with necessary components and aims to implement multivibrators (Bistable, Monostable, and Astable) and RC phase shift oscillators in the laboratory. A variable power supply is constructed in the trainer kit that provides 9 V dc to the multivibrators and 15 V dc to the oscillator. Potentiometer, voltage regulator, different active and passive components such as resistors, capacitor, op-amp, transistor, and numerous jumper wires are introduced in this kit. The trainer kit ascertains an easy implementation by eliminating complexity and assures accurate wave-shapes at the oscilloscope within a short time. To validate the proposed system, a survey program has been introduced among many students and faculty members. The outcome of the survey is the demonstration of student and instructor views and opinions which acknowledges the trainer kit as an efficient and compatible working platform.

Numerical Study of Density Ratio Influence on Global Wave Shapes Before Impact

The influence of the gas-to-liquid density ratio (DR) on the global wave shape before impact is studied through numerical simulations of the propagation of two different waves in a rectangular wave canal. Two different codes are used: the first one, named FSID, is a highly non-linear 2D bi-fluid potential code initially developed in the frame of SLOSHEL JIP (Kaminski et al. (2011)) to simulate incompressible inviscid free-surface flows without surface tension thanks to a desingularized technique and series of conformal mappings; the second one, named CADYF, is a bi-fluid high-fidelity front-tracking software developed by Ecole Polytechnique Montreal to simulate separated two-phase incompressible viscous flows with surface tension. The first studied wave leads to a flip-through impact while the second one leads to a large gas-pocket impact. Each condition is studied with water and three different gases with increasing densities corresponding to DR = 0.001, 0.003 and 0.005. The global wave shapes are compared a few tenths of second before the impact, before free surface instabilities triggered by the shearing gas flow have developed and also before any gas compressibility matters. Both codes give precisely the same global wave shapes. Whatever the condition studied, it is shown that DR has an influence on these global wave shapes. The trends observed from the simulations are the same as those described in Karimi et al. (2016) obtained from sloshing model tests with Single Impact Waves (SIW) in a 2D tank with a low filling level. A small part of the mechanical energy of the liquid is progressively given to the gas. The larger the DR, the larger this transfer of energy from the liquid to the gas. This explains an increasing delay of the wave front for increasing DRs.