Correction to “The role of porosity evolution in frictional instabilities: A parametric study using a spring-slider dynamic system”

2011 ◽  
Vol 38 (13) ◽  
pp. n/a-n/a ◽  
Author(s):  
Y. Mitsui ◽  
M. Cocco
Keyword(s):  
Dynamic System ◽  
Parametric Study ◽  
Porosity Evolution

Effects of Partially-Filled Containers in Dynamic Behavior of Tanker Trains Traveling on Curved Tracks

2008 ◽  
Author(s):  
Iman Hazrati Ashtiani ◽  
Davood Younesian ◽  
Mehrnoosh Abedi ◽  
Ebrahim Esmailzadeh
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Dynamic System ◽  
Dynamic Analysis ◽  
Parametric Study ◽  
Fluid Density ◽  
Moment Arms ◽  
Rail Irregularities ◽  
Curved Track ◽  
The Moment

Dynamic analysis of a partially-filled tanker train traveling on a curved track is studied in this paper. A partially-filled tanker is dynamically modeled when it is traveling along a real curved track. For three classes of tracks, rail irregularities are randomly generated by using Monte-Carlo simulation. An equivalent dynamic system is used to model sloshing motion of the fluid. Two derailment indexes i.e. derailment quotient and unloading ratio are obtained numerically as safety indicators. A parametric study is carried out to investigate how different parameters like the operational speed, fluid modeling, rail irregularities, and fluid density may affect the derailment potential. It is found that descending of the center of gravity and consequently reduction of the moment arms is more dominant than the oscillating forces due to sloshing motion.

scholarly journals Complex of global functional network as the core of consciousness

2021 ◽  
Author(s):  
Keiichi Onoda
Keyword(s):  
Dynamic System ◽  
Brain Activity ◽  
Posterior Part ◽  
Neural Basis ◽  
Attention Networks ◽  
The Core ◽  
Hierarchical Partition ◽  
Brain Fmri ◽  
The Brain

Finding the neural basis of consciousness is a challenging issue, and it is still inconclusive where the core of consciousness is distributed in the brain. The global neuronal workspace theory (GNWT) emphasizes the role of the frontoparietal regions, whereas the integrated information theory (IIT) argues that the posterior part of the brain is the core of consciousness. IIT has proposed “main complex” as the core of consciousness in a dynamic system, which is a set of elements that the information loss in a hierarchical partition approach is the largest among that of all its supersets and subsets. However, no experimental study has reported the core of consciousness using the main complex for actual brain activity. This study estimated the main complex of brain dynamics using a functional MRI. The whole-brain fMRI data of eight conditions (seven tasks and a rest state) were divided into multiple elements based on network atlases, and the main complex of the dynamic system was estimated for each condition. It is assumed that, if there is a set of elements in the complex that are common to all conditions, the set is likely to contain the core of consciousness. Executive control, salience, and dorsal/ventral attention networks were commonly included in the main complex across all conditions, implying that these networks are responsible for the core of consciousness. This finding is consistent with the GNWT, as these networks are across the prefrontal and parietal regions.

Parametric Study and Experimental Correlation of an SMA Based Damping and Passive Vibration Isolation Device

2002 ◽  
Author(s):  
Dimitris C. Lagoudas ◽  
Mughees M. Khan ◽  
John J. Mayes ◽  
Benjamin K. Henderson
Keyword(s):  
Dynamic System ◽  
Shape Memory ◽  
Parametric Study ◽  
Vibration Isolation ◽  
Preisach Model ◽  
Trade Offs ◽  
Passive Vibration Isolation ◽  
Non Linear ◽  
Prototype Device ◽  
Isolation Device

In this work, the effect of pseudoelastic response of shape memory alloys (SMAs) on damping and passive vibration isolation will be presented. This study has been conducted by developing and utilizing a shape memory alloy (SMA) model (a physically based SMA model) to perform extensive parametric studies on a non-linear hysteretic dynamic system, representing an actual SMA damping and passive vibration isolation prototype device. The prototype device consists of SMA tubes undergoing pseudoelastic transformations under transverse loading. To accurately model the non-linear hysteretic response of SMA tubes present in the prototype device, a Preisach model (an empirical model based on system identification) has also been modified to simulate the response of the prototype device. Both the simplified SMA model and the Preisach model have been utilized to perform experimental correlations with the results obtained from actual testing of the prototype device. The investigations show that variable damping and tunable isolation response are major benefits of SMA pseudoelasticity. Correlation of numerical simulations and experimental results has shown that large amplitude displacements causing phase transformations of SMA components are necessary for an SMA based vibration isolation device to be effective in reducing the transmissibility of a dynamic system. It has also been shown that SMA based devices can overcome performance trade-offs inherent in a typical softening spring-damper vibration isolation system. In terms of modeling, the Preisach model gave relatively accurate results due to close proximity in predicting actual SMA component behavior. However, for a generic parametric study, the simplified SMA model has been found to be more useful as it is motivated from the constitutive response of SMAs and hence, could easily incorporate different changes in system conditions.

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