scholarly journals Pathological Voice Source Analysis System Using a Flow Waveform-Matched Biomechanical Model

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Xiaojun Zhang ◽  
Lingling Gu ◽  
Wei Wei ◽  
Di Wu ◽  
Zhi Tao ◽  
...  
Keyword(s):  
Vocal Cord ◽  
Biomechanical Model ◽  
Source Analysis ◽  
Model Parameters ◽  
Mass Model ◽  
Voice Source ◽  
Fitting Procedure ◽  
Subglottal Pressure ◽  
Analysis System ◽  
Pathological Voice

Voice production occurs through vocal cord and vibration coupled to glottal airflow. Vocal cord lesions affect the vocal system and lead to voice disorders. In this paper, a pathological voice source analysis system is designed. This study integrates nonlinear dynamics with an optimized asymmetric two-mass model to explore nonlinear characteristics of vocal cord vibration, and changes in acoustic parameters, such as fundamental frequency, caused by distinct subglottal pressure and varying degrees of vocal cord paralysis are analyzed. Various samples of sustained vowel /a/ of normal and pathological voices were extracted from MEEI (Massachusetts Eye and Ear Infirmary) database. A fitting procedure combining genetic particle swarm optimization and a quasi-Newton method was developed to optimize the biomechanical model parameters and match the targeted voice source. Experimental results validate the applicability of the proposed model to reproduce vocal cord vibration with high accuracy, and show that paralyzed vocal cord increases the model coupling stiffness.

All Source Analysis System (ASAS). Block 1. Abbreviated HARDMAN analysis. Appendices to Volume 1

1992 ◽  
Author(s):  
James C. Whitfield ◽  
Kimball R. Stuhlmuller ◽  
Scott A. Jashinski ◽  
Edward Burke ◽  
Dean DeVault
Keyword(s):  
Source Analysis ◽  
Analysis System

Physiology and its Impact on the Performance of Singing

2015 ◽  
pp. 66-84
Author(s):  
Filipa M. B. Lã ◽  
Brian P. Gill
Keyword(s):  
Vocal Tract ◽  
Teaching Method ◽  
Vocal Technique ◽  
Voice Source ◽  
Advantages And Disadvantages ◽  
Physiological Processes ◽  
Subglottal Pressure ◽  
Source Signal ◽  
Frequency Components ◽  
Singing Performance

Singing performance is highly competitive; thus, finding strategies to accelerate the acquisition of knowledge that results in an efficient and effective vocal technique is of the utmost importance. There are many ways in which a singer may acquire an efficient and effective vocal technique, which can be based on the physiological processes of voice production. This chapter explores these processes within the context of singing performance. The authors examine three major aspects of singing: 1) efficient control of breathing, such that optimal airflow and subglottal pressure are available as needed, for a given frequency and intensity; 2) maximized laryngeal coordination, so that the voice source signal contains all the necessary frequency components for the desired tone; and 3) the modulation of the source signal by subtle shaping of the vocal tract. The advantages and disadvantages of various pedagogical methods are discussed, including breath management, known as appoggio, and different resonant strategies. The authors advocate for a scientifically-grounded teaching method, which allows for physiological differences between individuals, genders, and voice classifications.

scholarly journals Characterizing Vibrating Cantilevers for Liquid Viscosity and Density Sensing

2008 ◽  
Vol 2008 ◽  
pp. 1-9 ◽  
Author(s):  
Christian Riesch ◽  
Erwin K. Reichel ◽  
Franz Keplinger ◽  
Bernhard Jakoby
Keyword(s):  
Cross Sections ◽  
Quartz Crystal ◽  
Model Parameters ◽  
Additional Mass ◽  
Liquid Loading ◽  
Fitting Procedure ◽  
Saw Devices ◽  
Quartz Crystal Resonators ◽  
Macroscopic Parameters ◽  
Online Process

Miniaturized liquid sensors are essential devices in online process or condition monitoring. In case of viscosity and density sensing, microacoustic sensors such as quartz crystal resonators or SAW devices have proved particularly useful. However, these devices basically measure a thin-film viscosity, which is often not comparable to the macroscopic parameters probed by conventional viscometers. Miniaturized cantilever-based devices are interesting alternatives for such applications, but here the interaction between the liquid and the oscillating beam is more involved. In our contribution, we describe a measurement setup, which allows the investigation of this interaction for different beam cross-sections. We present an analytical model based on an approximation of the immersed cantilever as an oscillating sphere comprising the effective mass and the intrinsic damping of the cantilever and additional mass and damping due to the liquid loading. The model parameters are obtained from measurements with well-known sample liquids by a curve fitting procedure. Finally, we present the measurement of viscosity and density of an unknown sample liquid, demonstrating the feasibility of the model.

Neurophysiological Analysis of the Genesis Mechanism of EEG During the Interictal and Ictal Periods Using a Multiple Neural Masses Model

2017 ◽  
Vol 28 (01) ◽  
pp. 1750027 ◽  
Author(s):  
Zhen Ma
Keyword(s):  
Matching Pursuit ◽  
Neural Mass Model ◽  
Model Parameters ◽  
Eeg Signals ◽  
Neural Signals ◽  
Mass Model ◽  
Neurophysiological Mechanism ◽  
Norm Minimization ◽  
Neural Mass ◽  
Inhibitory Strength

Electroencephalography (EEG) is an important method to investigate the neurophysiological mechanism underlying epileptogenesis to identify new therapies for the treatment of epilepsy. The neurophysiologically based neural mass model (NMM) can build a bridge between signal processing and neurophysiology, which can be used as a platform to explore the neurophysiological mechanism of epileptogenesis. Most EEG signals cannot be regarded as the outputs of a single NMM with identical model parameters. The outputs of NMM are simple because the diversity of neural signals in the same NMM is ignored. To improve the simulation of EEG signals, a multiple NMM is proposed, the output of which is the linear combination of the outputs of all NMMs. The NMM number is not fixed and is minimized under the premise of guaranteeing the fitting effect. Orthogonal matching pursuit is used to solve a constrained [Formula: see text] norm minimization problem for NMM number and the strength of every NMM. The results showed that the NMM number was significantly lower during the ictal period than during the interictal period, and the strength of major NMMs increased. This indicates that neural masses fuse into fewer larger neural masses with greater strength. The distribution of excitatory and inhibitory strength during the ictal and interictal periods was similar, whereas the excitation/inhibition ratio was higher during the ictal period than during the interictal period.

Nonlinear Vocal Fold Dynamics in a Two-Mass Model of Speech Arising From Asymmetric Intraglottal Flow

2011 ◽  
Author(s):  
Byron D. Erath ◽  
Matías Zañartu ◽  
Sean D. Peterson ◽  
Michael W. Plesniak
Keyword(s):  
Vocal Fold ◽  
Vocal Tract ◽  
Vocal Folds ◽  
Attractive Alternative ◽  
Nonlinear Phenomena ◽  
Mass Model ◽  
Sustained Oscillations ◽  
Voiced Speech ◽  
Subglottal Pressure ◽  
Vocal Fold Dynamics

Voiced speech is initiated as air is expelled from the lungs and passes through the vocal tract inciting self-sustained oscillations of the vocal folds. While various approaches exist for investigating both normal and pathological speech, the relative inaccessibility of the vocal folds make multi-mass speech models an attractive alternative. Their behavior has been benchmarked with excised larynx experiments, and they have been used as analysis tools for both normal and disordered speech, including investigations of paralysis, vocal tremor, and breathiness. However, during pathological speech, vocal fold motion is often unstructured, resulting in chaotic motion and a wealth of nonlinear phenomena. Unfortunately, current methodologies for multi-mass speech models are unable to replicate the nonlinear vocal fold behavior that often occurs in physiological diseased voice for realistic values of subglottal pressure.

Extraction of Quasi-Linear Viscoelastic Parameters for Lower Limb Soft Tissues From Manual Indentation Experiment

1999 ◽  
Vol 121 (3) ◽  
pp. 330-339 ◽  
Author(s):  
Y. P. Zheng ◽  
A. F. T. Mak
Keyword(s):  
Lower Limb ◽  
Soft Tissues ◽  
Model Parameters ◽  
Viscoelastic Parameters ◽  
Fitting Procedure ◽  
Ultrasound Indentation ◽  
Initial Modulus ◽  
Linear Viscoelastic ◽  
Young Subjects ◽  
Three Body

A manual indentation protocol was established to assess the quasi-linear viscoelastic (QLV) properties of lower limb soft tissues. The QLV parameters were extracted using a curve-fitting procedure on the experimental indentation data. The load-indentation responses were obtained using an ultrasound indentation apparatus with a hand-held pen-sized probe. Limb soft tissues at four sites of eight normal young subjects were tested in three body postures. Four QLV model parameters were extracted from the experimental data. The initial modulus E0 ranged from 0.22 kPa to 58.4 kPa. The nonlinear factor E1 ranged from 21.7 kPa to 547 kPa. The time constant τ ranged from 0.05 s to 8.93 s. The time-dependent material parameter α ranged from 0.029 to 0.277. Large variations of the parameters were noted among subjects, sites, and postures.

scholarly journals BRANE UNIVERSES TESTED AGAINST ASTRONOMICAL DATA

2004 ◽  
Vol 13 (08) ◽  
pp. 1669-1702 ◽  
Author(s):  
MARIUSZ P. DABROWSKI ◽  
WŁODZIMIERZ GODŁOWSKI ◽  
MAREK SZYDŁOWSKI
Keyword(s):  
Cosmological Constant ◽  
Likelihood Method ◽  
Model Parameters ◽  
Density Parameter ◽  
Brane Model ◽  
Fitting Procedure ◽  
Type Ia ◽  
The Difference ◽  
Age Of The Universe ◽  
Phantom Matter

We discuss observational constrains coming from supernovae imposed on the behaviour of the Randall–Sundrum models. We test the models using the Perlmutter SNIa data as well as the new Knop and Tonry/Barris samples. The data indicates that, under the assumption that we admit zero pressure dust matter on the brane, the cosmological constant is still needed to explain current observations. We estimate the model parameters using the best-fitting procedure and the likelihood method. The observations from supernovae give a large value of the density parameter for brane matter Ωλ,0≃0.01 as the best fit. For high redshifts z>1.2, the difference between the brane model and the ΛCDM (Perlmutter) model becomes detectable observationally. From the maximum likelihood method we obtained the favored value of Ωλ,0=0.004±0.016 for Ωk,0=0 and Ω m ,0=0.3. This gives the limit Ωλ,0<0.02 at 1σ level. While the model with brane effects is preferred by the supernovae type Ia data, the model without brane fluid is still statistically admissible. We also discuss how fit depends on restrictions of the sample, especially with respect to redshift criteria. We also pointed out the property of sensitive dependence of results with respect to the choice of ℳ parameter. For comparison the limit on brane effects which comes from CMB anisotropies and BBN is also obtained. The uncertainty in the location of the first peak gives a stronger limit Ωλ,0<1.0×10-12, whereas from BBN we obtain that Ωλ,0<1.0×10-27. However, both very strict limits are obtained with the assumption that brane effects do not change the physics in the pre-recombination era, while the SNIa limit is model independent. We demonstrate that the fit to supernovae data can also be obtained if we admit the phantom matter p=-(4/3)ϱ on the brane, where this matter mimics the influence of the cosmological constant. We show that phantom matter enlarges the age of the universe on the brane which is demanded in cosmology. Finally, we propose to check for dark radiation and brane tension by the application of the angular diameter of galaxies minimum value test.

Biomechanical Model Representing Energy Storing Prosthetic Feet

2010 ◽  
Author(s):  
Francy L. Sinatra ◽  
Stephanie L. Carey ◽  
Rajiv Dubey
Keyword(s):  
Motion Analysis ◽  
Lower Limb ◽  
Biomechanical Model ◽  
Body Segment ◽  
Prosthetic Foot ◽  
Biomechanical Models ◽  
Prosthetic Feet ◽  
Analysis System ◽  
Lower Limb Amputees ◽  
Metabolic Information

Previous studies have been conducted to develop a biomechanical model for a human’s lower limb. Amongst them, there have been several studies trying to quantify the kinetics and kinematics of lower-limb amputees through motion analysis [5, 10, 11]. Currently, there are various designs for lower-limb prosthetic feet such as the Solid Ankle Cushion Heel (SACH) from Otto Bock (Minneapolis) or the Flex Foot from Ossur (California). The latter is a prosthetic foot that allows for flexibility while walking and running. Special interest has been placed in recording the capabilities of these energy-storing prosthetic feet. This has been done through the creation of biomechanical models with motion analysis. In these previous studies the foot has been modeled as a single rigid-body segment, creating difficulties when trying to calculate the power dissipated by the foot [5, 20, 21]. This project studies prosthetic feet with energy-storing capabilities. The purpose is to develop an effective way of calculating power by using a biomechanical model. This was accomplished by collecting biomechanical data using an eight camera VICON (Colorado) motion analysis system including two AMTI (BP-400600, Massachusetts) force plates. The marker set that was used, models the foot using several segments, hence mimicking the motion the foot undergoes and potentially leading to greater accuracy. By developing this new marker set, it will be possible to combine the kinematic and kinetic profile gathered from it with previous studies that determined metabolic information. This information will allow for the better quantification and comparison of the energy storage and return (ES AR) feet and perhaps the development of new designs.

scholarly journals Chaos and Stability of Spur Gear Transmission System for Locomotive Based on Energy Method and Floquet Theory

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Junguo Wang ◽  
Bo Lv ◽  
Yongxiang Zhao
Keyword(s):  
Floquet Theory ◽  
Gear Tooth ◽  
Spur Gear ◽  
Transmission System ◽  
Gear Transmission ◽  
Model Parameters ◽  
Lumped Mass ◽  
Mass Model ◽  
Model Parameter ◽  
Gear Transmission System

Considering the internal and external excitations such as time-varying mesh stiffness (TVMS), backlash, transmission error, torque of the traction motor, and load torque of the wheel/rail, a lumped mass model of the spur gear drive system for a railway locomotive is established. Based on Ma models in the relevant literatures, TVMS is calculated by simplifying a gear tooth as a cantilever beam on the root circle, taking into account the effects of extended tooth contact as well as revised foundation stiffness. The bifurcation diagrams and Lyapunov exponent curves of the model parameters are drawn by the numerical method, and the mechanism of chaos evolution of the gear transmission system is analyzed. According to the Floquet theory, variation curves of the maximum Floquet multiplier with pinion speed and support stiffness ratio are drawn by numerical methods. Combined with the bifurcation diagram of the system, the influences of model parameter on the stability of the system are analyzed, and the evolution laws of periodic motion and bifurcation phenomenon are gained. These research results provide the theoretical evidence of model parameter design of the locomotive transmission system.

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