An elementary model of torus canards

2011 ◽  
Vol 21 (2) ◽  
pp. 023131 ◽  
Author(s):  
G. Nicholas Benes ◽  
Anna M. Barry ◽  
Tasso J. Kaper ◽  
Mark A. Kramer ◽  
John Burke
Keyword(s):  
Elementary Model ◽  
Torus Canards

scholarly journals Canonical models for torus canards in elliptic bursters

2021 ◽  
Vol 31 (6) ◽  
pp. 063129
Author(s):  
E. Baspinar ◽  
D. Avitabile ◽  
M. Desroches
Keyword(s):  
Canonical Models ◽  
Torus Canards

Construction of an Elementary Model for the Dynamic Analysis of a Pressurized Water Reactor

2013 ◽  
Vol 284-287 ◽  
pp. 652-656 ◽  
Author(s):  
Chiung Wen Tsai ◽  
Chun Kuan Shih ◽  
Jong Rong Wang
Keyword(s):  
Transfer Functions ◽  
Feedback Loops ◽  
Dynamic Responses ◽  
Coolant Temperature ◽  
Inlet Temperature ◽  
Pressurized Water Reactor ◽  
Elementary Model ◽  
Pressurized Water ◽  
Water Reactor ◽  
Neutron Kinetics

A lumped-parameter numerical model was constructed based on the conservation laws of mass and energy and the point neutron kinetics with 6 groups of delayed neutron to represent the dynamics of primary loop of a pressurized water reactor (PWR) core. On the viewpoint of control theory, the coupled phenomenon of neutron kinetics and thermohydraulics can be recognized as a dynamic system with feedback loops which is caused by the Doppler effect and the coolant temperature difference. Scilab was implemented to representing the equivalent transfer functions and associated feedback loops of a PWR core. The dynamic responses were performed by the perturbations of coolant inlet flow, coolant inlet temperature, and reactivity insertion.

scholarly journals Generic torus canards

2017 ◽  
Vol 356-357 ◽  
pp. 37-64 ◽  
Author(s):  
Theodore Vo
Keyword(s):  
Torus Canards

Unsteady Numerical Simulation of the Flow in a Direct Transfer Pre-Swirl System

2008 ◽  
Author(s):  
Fabio Ciampoli ◽  
Nicholas J. Hills ◽  
John W. Chew ◽  
Timothy Scanlon
Keyword(s):  
Discharge Coefficient ◽  
Direct Transfer ◽  
Elementary Model ◽  
Discharge Coefficients ◽  
Significant Difference ◽  
Aero Engine ◽  
Velocity Coefficient ◽  
Unsteady Numerical Simulation ◽  
Unsteady Effects ◽  
Cooling Air

Results of fully unsteady numerical simulations of the flow in a direct transfer pre-swirl system are presented and compared with previously published experimental data from an aero-engine representative rig. The conditions considered include those where strong unsteady effects were observed experimentally. Two different rig builds are considered, with the main difference being in the design of the pre-swirl nozzles. The agreement between calculation and experiment is very good in terms of nozzle and receiver hole discharge coefficients and in identifying significant unsteady effects at certain conditions. Predicted cooling air delivery temperatures are lower than those measured. This may be due to heat transfer and other effects in the rig which have not been modelled. Present unsteady results also show agreement, where appropriate, with earlier steady CFD and an elementary model. Both calculations and measurements show similar performance in terms of delivery temperature for the two different builds studied, despite significant difference in pre-swirl nozzle discharge coefficients for the two builds. The calculations indicate that this is associated with the nozzle velocity coefficient being considerably higher than the discharge coefficient in one case.

scholarly journals Application of Modified Grey Forecasting Model to Predict the Municipal Solid Waste Generation using MLP and MLE

2021 ◽  
Vol 6 (5) ◽  
pp. 1276-1296
Author(s):  
Mohd Anjum ◽  
Sana Shahab ◽  
Mohammad Sarosh Umar
Keyword(s):  
Linear Regression ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Likelihood Estimation ◽  
Grey Model ◽  
Waste Generation ◽  
Elementary Model ◽  
Grey Forecasting ◽  
Solid Waste Generation ◽  
Forecasting Theory

Grey forecasting theory is an approach to build a prediction model with limited data to produce better forecasting results. This forecasting theory has an elementary model, represented as the GM(1,1) model , characterized by the first-order differential equation of one variable. It has the potential for accurate and reliable forecasting without any statistical assumption. The research proposes a methodology to derive the modified GM(1,1) model with improved forecasting precision. The residual series is forecasted by the GM(1,1) model to modify the actual forecasted values. The study primarily addresses two fundamental issues: sign prediction of forecasted residual and the procedure for formulating the grey model. Accurate sign prediction is very complex, especially when the model lacks in data. The signs of forecasted residuals are determined using a multilayer perceptron to overcome this drawback. Generally, the elementary model is formulated conventionally, containing the parameters that cannot be calculated straightforward. Therefore, maximum likelihood estimation is incorporated in the modified model to resolve this drawback. Three statistical indicators, relative residual, posterior variance test, and absolute degree of grey indices, are evaluated to determine the model fitness and validation. Finally, an empirical study is performed using actual municipal solid waste generation data in Saudi Arabia, and forecasting accuracies are compared with the linear regression and original GM(1,1). The MAPEs of all models are rigorously examined and compared, and then it is obtained that the forecasting precision of GM(1,1) model , modified GM(1,1) model, and linear regression is 15.97%, 8.90%, and 27.90%, respectively. The experimental outcomes substantiate that the modified grey model is a more suitable forecasting approach than the other compared models.

An elementary model of export tax war

2018 ◽  
Vol 154 (2) ◽  
pp. 307-325 ◽  
Author(s):  
Jean-Marc Malambwe Kilolo
Keyword(s):  
Elementary Model ◽  
Export Tax

An elementary model for fast detonations in tubular charges

2019 ◽  
Vol 23 (4) ◽  
pp. 573-591
Author(s):  
Irina Brailovsky ◽  
Leonid Kagan ◽  
Peter Gordon ◽  
Gregory Sivashinsky
Keyword(s):  
Elementary Model

Internal capacitance and resistance allow prediction of right ventricle outflow

1982 ◽  
Vol 243 (1) ◽  
pp. H99-H112 ◽  
Author(s):  
K. B. Campbell ◽  
J. A. Ringo ◽  
Y. Wakao ◽  
P. A. Klavano ◽  
J. E. Alexander
Keyword(s):  
Right Ventricle ◽  
Series Resistance ◽  
Predictive Performance ◽  
Ventricular Volume ◽  
Right Atrial ◽  
Model Structure ◽  
Time Varying ◽  
Predictive Capability ◽  
Elementary Model ◽  
Marginal Improvement

The relationship between right ventricle afterloading pressure (P) and outflow (Q) was studied in three isolated canine right ventricle (RV) preparations. Right atrial pressure was held constant while graded elevations in P were induced with stepwise occlusions of the right and left branches of the pulmonary artery. P and Q signals were collected and analyzed using a digital computer system. Data were analyzed by assuming a model structure for the RV and comparing resultant model predictions of Q with actual observations. The model structure was modified in accordance with the discrepancy between prediction and observation to improve the model's predictive capability. The initial model tested was the time-varying linear relationship between ventricular volume and pressure. Utilizing this model, accurate predictions of RV outflow in the face of varying pressure afterloads could not be made. The addition of a series resistance to this elementary model resulted in marked improvement in predictive performance. The addition of greater complexity to the model gave only marginal improvement to the model's predictive capability. It was concluded that a time-varying capacitance and series resistance adequately model internal properties of the RV that relate outflow to afterloading pressure.

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