Model-Based Assessment of Geophysical Observations: From Numerical Simulations Towards Volcano Hazard Forecasting

2014 ◽  
pp. 71-76
Author(s):  
Gilda Currenti ◽  
Ciro Del Negro
Keyword(s):  
Numerical Simulations ◽  
Model Based

scholarly journals Model-Based Analysis of Yo-yo Throwing Motion on Single-Link Manipulator

2020 ◽  
Vol 32 (4) ◽  
pp. 822-831
Author(s):  
Hokuto Miyakawa ◽  
◽  
Takuma Nemoto ◽  
Masami Iwase
Keyword(s):  
Angular Velocity ◽  
Numerical Simulations ◽  
Integrated Model ◽  
Analysis Method ◽  
Model Based ◽  
Single Link ◽  
Throwing Motion ◽  
Model Based Analysis

This paper presents a method for analyzing the throwing motion of a yo-yo based on an integrated model of a yo-yo and a manipulator. Our previous integrated model was developed by constraining a model of a white painted commercial yo-yo and a model of a plain single-link manipulator with certain constraining conditions placed between two models. However, for the yo-yo model, the collisions between the string and the axle of the yo-yo were not taken into account. To avoid this problem, we estimate some of the yo-yo parameters from the experiments, thereby preserving the functionality of the model. By applying the new integrated model with the identified parameters, we analyze the throwing motion of the yo-yo through numerical simulations. The results of which show the ranges of the release angle and the angular velocity of the joint of the manipulator during a successful throw. In conclusion, the proposed analysis method is effective in analyzing the throwing motion of a manipulator.

scholarly journals Numerical simulations of one laser-plasma model based on Poisson structure

2020 ◽  
Vol 405 ◽  
pp. 109172
Author(s):  
Yingzhe Li ◽  
Yajuan Sun ◽  
Nicolas Crouseilles
Keyword(s):  
Numerical Simulations ◽  
Poisson Structure ◽  
Laser Plasma ◽  
Plasma Model ◽  
Model Based

scholarly journals Model-based design of transverse wall oscillations for turbulent drag reduction

2012 ◽  
Vol 707 ◽  
pp. 205-240 ◽  
Author(s):  
Rashad Moarref ◽  
Mihailo R. Jovanović
Keyword(s):  
Turbulent Flow ◽  
Numerical Simulations ◽  
Eddy Viscosity ◽  
Traditional Approach ◽  
Turbulent Viscosity ◽  
Transverse Wall ◽  
Mean Velocity ◽  
Model Based ◽  
Turbulent Drag ◽  
Linearized Model

AbstractOver the last two decades, both experiments and simulations have demonstrated that transverse wall oscillations with properly selected amplitude and frequency can reduce turbulent drag by as much as $40\hspace{0.167em} \% $. In this paper, we develop a model-based approach for designing oscillations that suppress turbulence in a channel flow. We utilize eddy-viscosity-enhanced linearization of the turbulent flow with control in conjunction with turbulence modelling to determine skin-friction drag in a simulation-free manner. The Boussinesq eddy viscosity hypothesis is used to quantify the effect of fluctuations on the mean velocity in flow subject to control. In contrast to the traditional approach that relies on numerical simulations, we determine the turbulent viscosity from the second-order statistics of the linearized model driven by white-in-time stochastic forcing. The spatial power spectrum of the forcing is selected to ensure that the linearized model for uncontrolled flow reproduces the turbulent energy spectrum. The resulting correction to the turbulent mean velocity induced by small-amplitude wall movements is then used to identify the optimal frequency of drag-reducing oscillations. In addition, the control net efficiency and the turbulent flow structures that we obtain agree well with the results of numerical simulations and experiments. This demonstrates the predictive power of our model-based approach to controlling turbulent flows and is expected to pave the way for successful flow control at higher Reynolds numbers than currently possible.

Numerical simulations of semiconvection

2006 ◽  
Vol 2 (S239) ◽  
pp. 317-319 ◽  
Author(s):  
Guillaume P. Bascoul
Keyword(s):  
Prandtl Number ◽  
Numerical Simulations ◽  
Massive Star ◽  
Scaling Laws ◽  
Main Sequence ◽  
Neutral Layer ◽  
The Core ◽  
Model Based ◽  
Thermohaline Convection ◽  
High Prandtl Number

AbstractUsing a semiconvective model based on thermohaline convection, we investigate the case of an expanding core of a main-sequence massive star. The numerical simulations at high Prandtl number show a flow consistent with the assumption that a dynamically neutral layer sits between the core and the radiative envelope. More simulations at low Prandtl number are needed to infer scaling laws applicable to astrophysical regimes.

scholarly journals Asymmetric drop coalescence launches fungal ballistospores with directionality

2017 ◽  
Vol 14 (132) ◽  
pp. 20170083 ◽  
Author(s):  
Fangjie Liu ◽  
Roger L. Chavez ◽  
S. N. Patek ◽  
Anne Pringle ◽  
James J. Feng ◽  
...  
Keyword(s):  
Surface Energy ◽  
Numerical Simulations ◽  
Relative Position ◽  
Colloidal Particles ◽  
Mechanistic Model ◽  
Fungal Species ◽  
Adaxial Side ◽  
Drop Coalescence ◽  
Model Based ◽  
Directional Control

Thousands of fungal species use surface energy to power the launch of their ballistospores. The surface energy is released when a spherical Buller's drop at the spore's hilar appendix merges with a flattened drop on the adaxial side of the spore. The launching mechanism is primarily understood in terms of energetic models, and crucial features such as launching directionality are unexplained. Integrating experiments and simulations, we advance a mechanistic model based on the capillary–inertial coalescence between the Buller's drop and the adaxial drop, a pair that is asymmetric in size, shape and relative position. The asymmetric coalescence is surprisingly effective and robust, producing a launching momentum governed by the Buller's drop and a launching direction along the adaxial plane of the spore. These key functions of momentum generation and directional control are elucidated by numerical simulations, demonstrated on spore-mimicking particles, and corroborated by published ballistospore kinematics. Our work places the morphological and kinematic diversity of ballistospores into a general mechanical framework, and points to a generic catapulting mechanism of colloidal particles with implications for both biology and engineering.

The Berry-Esseen bound of a wavelet estimator in non-randomly designed nonparametric regression model based on ANA errors

2020 ◽  
Vol 24 ◽  
pp. 21-38
Author(s):  
Xufei Tang ◽  
Xuejun Wang ◽  
Yi Wu ◽  
Fei Zhang
Keyword(s):  
Regression Model ◽  
Numerical Simulations ◽  
Nonparametric Regression ◽  
Random Variables ◽  
Nonparametric Regression Model ◽  
Wavelet Estimator ◽  
Negatively Associated ◽  
Model Based

Consider the nonparametric regression model Yni = g(tni) + εi, i = 1, 2, …, n,  n ≥ 1, where εi,  1 ≤ i ≤ n, are asymptotically negatively associated (ANA, for short) random variables. Under some appropriate conditions, the Berry-Esseen bound of the wavelet estimator of g(⋅) is established. In addition, some numerical simulations are provided in this paper. The results obtained in this paper generalize some corresponding ones in the literature.

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