A Simulation Study on the Effect of Glottal Boundary Conditions on Vocal Tract Formants

2017 ◽  
Author(s):  
Yasufumi Uezu ◽  
Tokihiko Kaburagi
Keyword(s):  
Boundary Conditions ◽  
Simulation Study ◽  
Vocal Tract

A digital vocal tract simulator with boundary conditions at lips and glottis

1981 ◽  
Vol 64 (11) ◽  
pp. 18-26 ◽  
Author(s):  
Tetsuya Nomura ◽  
Nobuhiro Miki ◽  
Nobuo Nagai
Keyword(s):  
Boundary Conditions ◽  
Vocal Tract

scholarly journals Effects of Loading and Boundary Conditions on the Performance of Ultrasound Compressional Viscoelastography: A Computational Simulation Study to Guide Experimental Design

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2590
Author(s):  
Che-Yu Lin ◽  
Ke-Vin Chang
Keyword(s):  
Boundary Conditions ◽  
Simulation Study ◽  
Viscoelastic Properties ◽  
Measurement Accuracy ◽  
Computational Simulation ◽  
Vertical Direction ◽  
Fixation Method ◽  
Element Analysis ◽  
Sample Container

Most biomaterials and tissues are viscoelastic; thus, evaluating viscoelastic properties is important for numerous biomedical applications. Compressional viscoelastography is an ultrasound imaging technique used for measuring the viscoelastic properties of biomaterials and tissues. It analyzes the creep behavior of a material under an external mechanical compression. The aim of this study is to use finite element analysis to investigate how loading conditions (the distribution of the applied compressional pressure on the surface of the sample) and boundary conditions (the fixation method used to stabilize the sample) can affect the measurement accuracy of compressional viscoelastography. The results show that loading and boundary conditions in computational simulations of compressional viscoelastography can severely affect the measurement accuracy of the viscoelastic properties of materials. The measurement can only be accurate if the compressional pressure is exerted on the entire top surface of the sample, as well as if the bottom of the sample is fixed only along the vertical direction. These findings imply that, in an experimental validation study, the phantom design should take into account that the surface area of the pressure plate must be equal to or larger than that of the top surface of the sample, and the sample should be placed directly on the testing platform without any fixation (such as a sample container). The findings indicate that when applying compressional viscoelastography to real tissues in vivo, consideration should be given to the representative loading and boundary conditions. The findings of the present simulation study will provide a reference for experimental phantom designs regarding loading and boundary conditions, as well as guidance towards validating the experimental results of compressional viscoelastography.

scholarly journals Impact of Boundary Conditions on the Performance Enhancement of Advanced Control Strategies for a Residential Building with a Heat Pump and PV System with Energy Storage

Energies ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1413
Author(s):  
Emmanouil Psimopoulos ◽  
Fatemeh Johari ◽  
Chris Bales ◽  
Joakim Widén
Keyword(s):  
Energy Storage ◽  
Boundary Conditions ◽  
Heat Pump ◽  
Simulation Study ◽  
Control Strategies ◽  
Thermal Storage ◽  
Hot Water ◽  
Final Energy ◽  
Advanced Control ◽  
The Impact

Operational control strategies for the heating system of a single-family house with exhaust air heat pump and photovoltaic system and “smart” utilization of energy storage have been developed and evaluated in a simulation study. The main aim and novelty of this study is to evaluate the impact on the benefit of these advanced control strategies in terms of performance (energy use and economic) for a wide range of boundary conditions (country/climate, occupancy and appliance loads). Short-term weather data and historic price data for the same year as well as stochastic occupancy profiles that include the domestic hot water load are used as boundary for a parametric simulation study for the system modeled in detail in TRNSYS 17. Results show that the control using a forecast of dynamic electricity price leads to greater final energy savings than those due to the control using thermal storage for excess PV production in all of the examined locations except Sweden. The impact on self-consumption using thermal storage of heat produced by the heat pump using excess PV production is found to decrease linearly with increasing household electricity for all locations. A reduction in final energy of up to 842 kWh year−1 can be achieved just by the use of these algorithms. The net energy cost for the end-user follows the same trend as for final energy and can result in cost savings up to 175 € year−1 in Germany and Spain due to the use of the advanced control.

Magnetic resonance electrical properties tomography for small anomalies using boundary conditions: A simulation study

2017 ◽  
Vol 44 (9) ◽  
pp. 4773-4785 ◽  
Author(s):  
Joonsung Lee ◽  
Narae Choi ◽  
Jin Keun Seo ◽  
Dong-Hyun Kim
Keyword(s):  
Magnetic Resonance ◽  
Electrical Properties ◽  
Boundary Conditions ◽  
Simulation Study

scholarly journals Adaptive Integral Sliding Mode Based Course Keeping Control of Unmanned Surface Vehicle

2022 ◽  
Vol 10 (1) ◽  
pp. 68
Author(s):  
José Antonio González-Prieto ◽  
Carlos Pérez-Collazo ◽  
Yogang Singh
Keyword(s):  
Boundary Conditions ◽  
Control Problem ◽  
Simulation Study ◽  
Sliding Mode ◽  
External Disturbances ◽  
Unmanned Surface Vehicle ◽  
Yaw Rate ◽  
Different Types ◽  
Unknown Disturbances ◽  
System Uncertainties

This paper investigates the course keeping control problem for an unmanned surface vehicle (USV) in the presence of unknown disturbances and system uncertainties. The simulation study combines two different types of sliding mode surface based control approaches due to its precise tracking and robustness against disturbances and uncertainty. Firstly, an adaptive linear sliding mode surface algorithm is applied, to keep the yaw error within the desired boundaries and then an adaptive integral non-linear sliding mode surface is explored to keep an account of the sliding mode condition. Additionally, a method to reconfigure the input parameters in order to keep settling time, yaw rate restriction and desired precision within boundary conditions is presented. The main strengths of proposed approach is simplicity, robustness with respect to external disturbances and high adaptability to static and dynamics reference courses without the need of parameter reconfiguration.

Prediction of Microstructure and Resulting Rolling Forces by Application of a Material Model in a Hot Ring Rolling Process

2014 ◽  
Vol 622-623 ◽  
pp. 970-977 ◽  
Author(s):  
Gideon Schwich ◽  
Thomas Henke ◽  
Joachim Seitz ◽  
Gerhard Hirt
Keyword(s):  
Finite Element ◽  
Boundary Conditions ◽  
Simulation Study ◽  
Rolling Process ◽  
Ring Rolling ◽  
Transfer Time ◽  
Bulk Forming ◽  
Good Accordance ◽  
Ring Rolling Process ◽  
The Impact

Ring rolling is a versatile incremental bulk forming process. Due to the incremental character of the process, it consists of a large number of deformation and dwell steps. Finite element (FE) simulations of bulk forming processes are capable of predicting loads, stresses and material flow. In recent years, the finite element analysis of ring rolling processes has become feasible both in terms of calculation time as well as regarding the closed loop control of the kinematic degrees of freedom [1]. Accordingly, the focus of interest now includes the prediction of the microstructure evolution. The accuracy of such numerical simulations strongly depends on the models characterizing the material behavior and boundary conditions. In this paper, a finite element based simulation study was conducted, in order to evaluate the impact of boundary conditions such as transfer time, radiation, heat transfer and friction on the target values of the ring rolling process. The results of the simulation study were compared to ring rolling experiments on an industrial size ring rolling device. A good accordance regarding the evolution of the outer diameter and radial force was observed. Strong contingencies of transfer time on the forces throughout the process were detected and considered in the simulation study. In a post processing step, the evolution of the microstructure considering the dynamic and static recrystallization as well as the grain growth was calculated using the FE results. The calculated grain sizes show good accordance with the experimentally observed microstructure of the ring before and after the rolling. Furthermore, the impact of process parameters on the evolution of the grain size was investigated.

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