Resonance Box Research Articles

Federico Fellini’s effect in Argentine cinema: The case of Leonardo Favio

A self-taught artist initially trained alongside Leopoldo Torre Nilsson, and considered today by both his country’s critics and his peers as one of the most important Argentinean directors, if not the most important, Leonardo Favio (1938–2012) often expressed his views on Italian cinema and Federico Fellini’s films without openly acknowledging their effect on his films. Despite this positioning, I intend to illustrate in this article how Favio’s cinematic universe has been traversed and shaped by Italian cinema, as by a red thread. More precisely, I aim to highlight how Favio, after incorporating several themes, characters and approaches of neorealist cinema in his only short and in his first film, included dialogues with Fellini’s cinematic universe in almost all his subsequent releases. The encounter with the cinema of Italian Maestro, without ever diminishing the originality and specificity of Favio’s films, turns them into a sort of resonance box for Fellinian echoes.

Effectiveness and brain mechanism of multi-target transcranial alternating current stimulation (tACS) on motor learning in stroke patients: study protocol for a randomized controlled trial

BackgroundTranscranial alternating current stimulation (tACS) has proven to be an effective treatment for improving cognition, a crucial factor in motor learning. However, current studies are predominantly focused on the motor cortex, and the potential brain mechanisms responsible for the therapeutic effects are still unclear. Given the interconnected nature of motor learning within the brain network, we have proposed a novel approach known as multi-target tACS. This study aims to ascertain whether multi-target tACS is more effective than single-target stimulation in stroke patients and to further explore the potential underlying brain mechanisms by using techniques such as transcranial magnetic stimulation (TMS) and magnetic resonance imaging (MRI).MethodsThis study employs a double-blind, sham-controlled, randomized controlled trial design with a 2-week intervention period. Both participants and outcome assessors will remain unaware of treatment allocation throughout the study. Thirty-nine stroke patients will be recruited and randomized into three distinct groups, including the sham tACS group (SS group), the single-target tACS group (ST group), and the multi-target tACS group (MT group), at a 1:1:1 ratio. The primary outcomes are series reaction time tests (SRTTs) combined with electroencephalograms (EEGs). The secondary outcomes include motor evoked potential (MEP), central motor conduction time (CMCT), short interval intracortical inhibition (SICI), intracortical facilitation (ICF), magnetic resonance imaging (MRI), Box and Block Test (BBT), and blood sample RNA sequencing. The tACS interventions for all three groups will be administered over a 2-week period, with outcome assessments conducted at baseline (T0) and 1 day (T1), 7 days (T2), and 14 days (T3) of the intervention phase.DiscussionThe study’s findings will determine the potential of 40-Hz tACS to improve motor learning in stroke patients. Additionally, it will compare the effectiveness of multi-target and single-target approaches, shedding light on their respective improvement effects. Through the utilization of techniques such as TMS and MRI, the study aims to uncover the underlying brain mechanisms responsible for the therapeutic impact. Furthermore, the intervention has the potential to facilitate motor learning efficiency, thereby contributing to the advancement of future stroke rehabilitation treatment.Trial registrationChinese Clinical Trial Registry ChiCTR2300073465. Registered on 11 July 2023.

Virtual Simulation Research on Resonance Box Vibration Characteristics of College Symphony Orchestra Driven by Artificial Intelligence Technology

Abstract This study focuses on applying artificial intelligence techniques to virtually simulate the vibration characteristics of the resonance box of a college symphony orchestra to improve the understanding and optimization of the acoustic performance of the instrument. The study uses the finite element method and digital waveguide technology to simulate and analyze the vibration characteristics of the stringed resonating musical instrument, which is realized by the vibration equation of an ideal string and the principle of digital waveguide algorithm. The experimental results show that the applied simulation technique can effectively simulate the vibration characteristics of the resonance box of the musical instrument, such as the ideal string vibration and the cavity coupling effect. In addition, the study involves the mathematical expressions of forced vibration and resonance and the effects of various materials on the modal frequencies of the resonance box. The application of artificial intelligence technology in studying acoustic characteristics of musical instruments significantly improves the accuracy and efficiency of simulation. It provides essential theoretical support for the design and production of musical instruments.

The Logic and Practical Path of Higher Education Curriculum Reform Based on Cognitive Psychology

Abstract Based on cognitive psychology theory, this study explores the doctrinal logic and practical path of higher education curriculum reform to enhance the effectiveness of higher education programs, with particular attention to improving students’ psychological quality and learning effectiveness. The study uses the finite element method and digital waveguide technology to simulate and analyze the stringed musical instrument. Accurate simulation of the vibration characteristics of the musical instrument is realized through the vibration equations of an ideal string and the principles of the digital waveguide algorithm. The experimental results show that the applied simulation technique can effectively simulate the vibration characteristics of the resonance box of the musical instrument, such as the ideal string vibration and the cavity coupling effect. In addition, the study involves the mathematical expressions of forced vibration and resonance and the effects of various materials on the modal frequencies of the resonance box. The application of artificial intelligence technology in studying acoustic properties of musical instruments significantly improves the accuracy and efficiency of simulation. It provides essential theoretical support for the design and production of musical instruments.

Kalimba tine boundary condition models

The kalimba or African thumb piano is a musical instrument with thin metal tines plucked by the thumbs at their free end. The opposite end is secured to a wood resonator with a three-point clamp that provides downward force in the middle, between points of upward force at the bridge and the back bar. The simplest model is an Euler-Bernoulli thin beam, free at the plucked end and clamped at the mount. Chapman [J. Acoust. Soc. Am 131, 945 (2012)] explored the benefits to modeling the bridge as a simply supported point, with a clamped condition at the load point in the middle. Considerations in the present work are related to the modes of vibration of the resonator box. (i) The bridge is the point where vibration is transmitted to the resonator box, itself designed to better radiate sound, and thus the mechanical impedance at that point provides a complex boundary condition to be implemented in the tine model. (ii) Measurements of the attack of the kalimba tones include harmonic content not predicted by the thin beam model; recent work on this “offset” boundary condition is approached computationally, extending beyond the theoretical thin beam model.

The Sound Characteristics Of The Baglama With Respect To Different Chest Shapes

Baglama is the most common folk string instrument in Turkey. It has a bowl-shaped resonator box called a chest which amplifies the sound. The chest can be constructed in various forms by the luthiers. This study aims to determine the sound characteristics of the baglama associated with different chest forms. First, a prototypical baglama was modeled and analyzed numerically with the SolidWorks, HyperMesh and Actran software programs. Operational Deflection Shape (ODS) measurements of the baglama were also carried out experimentally. The numerical results were compared with the experimental ones and had an excellent agreement. Using this experimentally validated numerical model, the natural frequencies, mode shapes and sound propagation properties of the baglama were investigated for chests of different geometries.

Authentication of a Stradivarius “Petite Violin” Type from 1723

By correlating the structural–functional dimensional data with a series of archaeometric and chemometric characteristics determined by dendrochronological analysis and by three instrumental techniques (Scanning Electronic Microscopy, coupled with Energy Dispersive X-ray, µ-FTIR Spectroscopy and Thermal Analysis in Dynamic Mode), a Stradivarius violin was authenticated as having been made by one of the two Stradivari sons (Francesco or Omobono) in 1723. It should be noted that the “petite” type violin, which comes from a private collection and was recently purchased on the open market, has the original label and is in a poor preservation state. There is only one revarnishing intervention on the violin, and it is older than 80 years. There have been several attempts at sampling (all of which are under 30 years old) for the wooden support and varnish (from the top cover of the resonance box), but the existence of some analysis results is unknown. The dimensional characteristics of the structural–functional components place the violin in “petite violins”, and it is one of the more than 40 still preserved as an authentic artifact.

Design of Micro Power Energy Harvesting by Using High-Powered Engine Noise (Case Study: Generator Set ITK)

Study on design of micro power energy harvesting using high-power engine noise was aimed to compare the output voltage generated between random noise and stable noise and also determined the piezoelectric circuit variation which produced by ITK’s generator set noise. The noise energy harvester consisted of a quarter wavelength resonator box, three fins, and 3 ceramics piezoelectric. Function generator used to produce a stable wave and the ITK’s engine used to generate random wave. The first experimental result showed that piezoelectric average output voltage from noise engine was higher than noise from function generator when the circuit variation was 1 piezoelectric, parallel circuit, and 3 parallel-series piezoelectric and the opposite, series circuits generated average output voltage was the lowest. The pattern of piezolectric average output voltage which was generated from noise engine source fluctuates, didn’t as stable as noise function generator. This research also got the result that three series piezoelectric generated average output voltage higher than the others with the value of 201,07 mV when SPL and f respectively was 103,5 dB and 223,62 Hz. A higher output would be generated by increase the number of piezoelectric and arranged them into series circuit.

A Review of Finite Element Studies in String Musical Instruments

String instruments are complex mechanical vibrating systems, in terms of both structure and fluid–structure interaction. Here, a review study of the modeling and simulation of stringed musical instruments via the finite element method (FEM) is presented. The paper is focused on the methods capable of simulating (I) the soundboard behavior in bowed, plucked and hammered string musical instruments; (II) the assembled musical instrument box behavior in bowed and plucked instruments; (III) the fluid–structure interaction of assembled musical instruments; and (IV) the interaction of a musical instrument’s resonance box with the surrounding air. Due to the complexity and the high computational demands, a numerical model including all the parts and the full geometry of the instrument resonance box, the fluid–structure interaction and the interaction with the surrounding air has not yet been simulated.

Dual-Frequency High-Electric-Field Generator for MRI Safety Testing of Passive Implantable Medical Devices

In this article, an electric (E) field generator is developed to generate uniform and high-strength E-fields at multiple frequencies. The system can be used to assess the radio frequency (RF) hazards of implantable medical devices (IMDs) in magnetic resonance imaging (MRI) environments. The novel system consists of three parts: 1) a signal generating and amplifying block; 2) a four-channel feeding network; and 3) a rectangular resonator box. Mixed modes are utilized to generate locally uniform E-fields inside the rectangular resonator at both 64 and 128 MHz. RF-induced heating for two passive IMD families are evaluated using both numerical and experimental methods inside the E-field generator. These results are compared with those obtained from standard American Society of Testing and Materials (ASTM) phantom testing. The results show that the novel E-field generator is capable of evaluating RF-induced heating for passive IMDs similar to that of the ASTM phantom. Furthermore, it integrates both 1.5- and 3-T RF-induced heating tests in a single system. It is much simpler compared to the ASTM test method which needs the RF coil as a source. Consequently, this small and efficient E-field generator can be used as an alternative system for RF-induced heating tests of passive IMDs in the MRI environment.

Extracting Vibration Characteristics and Performing Sound Synthesis of Acoustic Guitar to Analyze Inharmonicity

The produced sound quality of guitar primarily depends on vibrational characteristics of the resonance box. Also, the tonal quality is influenced by the correct combination of tempo along with pitch, harmony, and melody in order to find music pleasurable. In this study, the resonance frequencies of the modelled resonance box have been analysed. The free-free modal analysis was performed in ABAQUS to obtain the modes shapes of the un-constrained sound box. To find music pleasing to the ear, the right pitch must be set, which is achieved by tuning the guitar strings. In order to analyse the sound elements, the Fourier analysis method was chosen and implemented in MATLAB. Identification of fundamentals and overtones of the individual string sounds were carried out prior and after tuning the string. The untuned strings showed irregular fundamental frequencies and higher partials of decay. Octaves and power spectrums have been presented and discussed in this paper.

On auditory choreography: How walking anticipates sound and movement resonates

Abstract Benjamin Vandewalle and Yoann Durant label their performance as an auditory choreography. Starting from an elaboration on the etymology of choreography I research what the auditory dimension adds and changes to choreography. Choreographing based on auditory decisions inverses sound and movement. This inversion has consequences from the process to the end result. Based on the sonic quality as main decision principle I unravel the creation process of Hear in seven main action: to stand, to walk, to breathe, to look, to move, to disappear and to sound. This division reveals how the actual choreographing doesn't stop at the end of the creation process. In the second half of the paper, I turn to the experience of an auditory choreography, where the body of the audience functions as a resonance box. The discomfort of a blindfold during the experience, leads to the installation of a delicate intimacy and reveals the close connection between sound, touch and movement. The precariousness of the installed intimacy triggers and enforces the audience imagination. Through my own experience of Hear I discover how the audience in an auditory choreography becomes a co-creator.

Detection of coupled vibration modes of a guitar resonance box.

Guitar is a popular musical instrument, but the design mainly depends on experience because of its complex structure. Based on resonant absorption mechanical spectra, a device has been developed to detect the coupled vibration modes of a guitar resonance box. The resonant frequencies of the guitar string are measured, and its dispersion relations accord with theoretical calculation. Two resonant absorption peaks at 81 Hz and 116 Hz have been found to be the coupled vibration modes of the resonance box of a guitar, which contribute to its acoustical quality.

Muhammad Ali. Un'icona dell'emancipazione degli afroamericani

Heavyweight champion Muhammad Ali’s worldwide fame resulted not only from his extraordinary accomplishments in the ring but also from his unconventional social activism, public fight against racial discrimination, forthright commitment to black separatism, and blunt criticism of the Vietnam War. The article outlines Ali’s role as a spokesperson and resonance box for the radical wing of the African-American community, highlighting a few contradictions and a subsequent switch to a less extremist stance that eventually enabled the whole U.S. society to identify itself with him.

Spatial distribution, territoriality and sound production by tropical cryptic butterflies (Hamadryas, Lepidoptera: Nymphalidae): implications for the ''industrial melanism" debate

Las Hamadryas son mariposas neotropicales que emiten sonido y pasan mucho tiempo posadas en árboles, donde son crípticas. Se estudió cinco especies en Costa Rica y Panama. Cada especie tiene una altura característica para posarse. Se posaron menos del lado sur de los árboles y evitaron las partes soleadas en días calurosos. Los machos dejaron su percha para volar hacia otras Hamadryas y hacia "mariposas" de cartón. Cuando se retiró los machos de los árboles éstos fueron tomados con mucha mayor frecuencia por otros machos. La mayoría de las interacciones aéreas de H. femnia se dieron entre las 1 3 : 00 y las 1 5 :00 h y fueron más frecuentes en la estación lluviosa. De noche, los machos compartían los árboles. El sonido característico del grupo es producido por venas modificadas en las alas delanteras.

The Sound Field Around a Tuning Fork and the Role of a Resonance Box

Atypical two-tine tuning fork is barely audible when held vibrating at an arm's length. It is enough, however, to touch its base to a table or, better, to a resonance box and the emitted sound becomes much louder. An inquiring student may pose questions: Why is a bare tuning fork such a weak emitter of sound?What is the role of the resonance box?Where does energy connected with larger intensity of emitted acoustic waves come from?

Vibration Characteristics of Violin Bow String and its Timbre Effect

This paper analyzes the modes of vibration of the strings and the strings of the material, the thickness effect on pronunciation, the establishment of a mass-spring model of vibrating strings and studied when the force pulling the strings and plucked violins panel vibration. Spectrum analysis and processing by MATLAB, the vibration of the resonance box is directly converted into sound, a sound judgment using spectral analysis methods.

Towards a physical model of the berimbau: Obtaining the modal synthesis of the cabaza

The worldwide presence of Brazilian culture grows every day. However, some of the musical instruments used in its principal cultural activities lack of a formal acoustic analysis which would make them more understandable for the rest of the world. One of them is the berimbau-de-barriga (berimbau), which consists of a string (wire) attached to an arched rod and a resonance box called cabaza. Modeling the berimbau will not only open up possibilities for its application to other musical genres, but will also allow the incorporation of its characteristics into new virtual instruments. The present work describes the modal synthesis of the cabaza, i.e., modeling this sounding box as a parallel bank of digital resonators. Impulse response measurements were obtained using a force hammer, and second-order resonator frequency-responses were fit to the data using Matlab.

Tonal characterisation of a wooden resonance box

In acoustic studies of musical string instruments, it is a common practice to identify vibration modes of the instrument resonance box. Usually, when a finite element method is employed, typical shell elements instead of solid elements are used for modelling the box, and its viscous properties are typically not taken into account. Although previous researches have indicated that this does not have much impact on the calculation of vibration modes, questions arise when the characteristics of a tonal signal are to be investigated. The problem with such modelling practice is that when shell elements are used and viscous properties are excluded, can we still effectively distinguish the subtle differences of tonal characteristics among those fine instruments. In this work we examine the effects of using different types of finite elements as well as applying viscoelastic properties of wooden materials on the tonal characteristics of sound radiation. By conducting this research for a simply structured wooden resonance box, we are attempting to answer questions such as whether we can afford to exclude either viscous properties or the use of solid elements or both in the study of tonal characteristics. If this is not permissible, then in what way these properties will affect the tonal characteristics.

Research on Mechanical Fault Diagnosis Based on Cascaded Bistable Stochastic Resonance and Fractal Box Dimension

Combining the filtering performance of cascaded bistable stochastic resonance with measurement capability of fractal box dimension for non-linear characteristics of signals, a method of mechanical fault diagnosis based on cascaded bistable stochastic resonance and fractal box dimension was presented. The experiment results showed that this method removed high frequency noise efficiently and obtained precise fractal dimension. In order to implement mechanical fault diagnosis, the non-linear characteristics of mechanical vibration signals were measured by fractal dimension accurately.