Stratified flow with natural convection weakly stratified fluid

2016 ◽  
Vol 11 (1) ◽  
pp. 88-93
Author(s):  
K.V. Moiseev
Keyword(s):  
Mathematical Model ◽  
Natural Convection ◽  
Linear Approximation ◽  
Layered Structure ◽  
Stratified Flow ◽  
Flow Cell ◽  
Stratified Fluid ◽  
Model Based ◽  
Layered Flows

In work on the basis of a mathematical model based on a linear approximation, we study the formation of the layered flows with natural convection, poorly stratified inhomogeneous liquid. The regions of the parameters under which a layered structure of the flow-cell in a side heating.

Optimal control strategy for cancer remission using combinatorial therapy: A mathematical model-based approach

2021 ◽  
Vol 145 ◽  
pp. 110789
Author(s):  
Parthasakha Das ◽  
Samhita Das ◽  
Pritha Das ◽  
Fathalla A. Rihan ◽  
Muhammet Uzuntarla ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Optimal Control ◽  
Control Strategy ◽  
Optimal Control Strategy ◽  
Combinatorial Therapy ◽  
Model Based ◽  
Cancer Remission

A note on design-based versus model-based variance estimation in stereology

2002 ◽  
Vol 34 (03) ◽  
pp. 484-490 ◽  
Author(s):  
Asger Hobolth ◽  
Eva B. Vedel Jensen
Keyword(s):  
Mathematical Model ◽  
Original Problem ◽  
Variance Estimation ◽  
Point Of View ◽  
Systematic Sampling ◽  
Variance Estimator ◽  
Shape Model ◽  
Model Based ◽  
Versus Model ◽  
Special Case

Recently, systematic sampling on the circle and the sphere has been studied by Gual-Arnau and Cruz-Orive (2000) from a design-based point of view. In this note, it is shown that their mathematical model for the covariogram is, in a model-based statistical setting, a special case of the p-order shape model suggested by Hobolth, Pedersen and Jensen (2000) and Hobolth, Kent and Dryden (2002) for planar objects without landmarks. Benefits of this observation include an alternative variance estimator, applicable in the original problem of systematic sampling. In a wider perspective, the paper contributes to the discussion concerning design-based versus model-based stereology.

scholarly journals 27 years of the HIV epidemic amongst men having sex with men in the Netherlands: An in depth mathematical model-based analysis

Epidemics ◽  
2010 ◽  
Vol 2 (2) ◽  
pp. 66-79 ◽  
Author(s):  
Daniela Bezemer ◽  
Frank de Wolf ◽  
Maarten C. Boerlijst ◽  
Ard van Sighem ◽  
T. Deirdre Hollingsworth ◽  
...  
Keyword(s):  
Mathematical Model ◽  
The Netherlands ◽  
Model Based ◽  
Hiv Epidemic ◽  
Sex With Men ◽  
Model Based Analysis

Fitting Spherical Surface and Evaluating Sphericity Error Based on the Minimum Zone Principle

2014 ◽  
Vol 687-691 ◽  
pp. 1373-1376 ◽  
Author(s):  
Lei Zhang ◽  
Li Li Liu ◽  
Chuan Hui Huang ◽  
Xing Hua Lu ◽  
Gen Sun
Keyword(s):  
Mathematical Model ◽  
Spherical Surface ◽  
Least Square ◽  
Model Based ◽  
Minimum Zone

To address the fitting spherical surface and evaluating sphericity error, a mathematical model based on the minimum zone principle is presented. And the presented model is answered by GA. An example shows the performance of the proposed method by comparison with the methods based on the least square principle.

scholarly journals Model-Based Design Approach to Improve Performance Characteristics of Hydrostatic Bearing Using Multivariable Optimization

Mathematics ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 388
Author(s):  
Waheed Ur Rehman ◽  
Xinhua Wang ◽  
Yiqi Cheng ◽  
Yingchun Chen ◽  
Hasan Shahzad ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Feedback Control ◽  
External Load ◽  
Sliding Mode ◽  
Feedforward Control ◽  
Spindle Speed ◽  
Performance Criteria ◽  
Model Based ◽  
Hydrostatic Bearings ◽  
Robust Control Design

Research in the field of tribo-mechatronics has been gaining popularity in recent decades. The objective of the current research is to improve static/dynamics characteristics of hydrostatic bearings. Hydrostatic bearings always work in harsh environmental conditions that effect their performance, and which may even result in their failure. The current research proposes a mathematical model-based system for hydrostatic bearings that helps to improve its static/dynamic characteristics under varying conditions of performance-influencing variables such as temperature, spindle speed, external load, and clearance gap. To achieve these objectives, the capillary restrictors are replaced with servo valves, and a mathematical model is developed along with robust control design systems. The control system consists of feedforward and feedback control techniques that have not been applied before for hydrostatic bearings in the published literature. The feedforward control tries to remove a disturbance before it enters the system while feedback control achieves the objective of disturbance rejection and improves steady-state characteristics. The feedforward control is a trajectory-based controller and the feedback controller is a sliding mode controller with a PID sliding surface. The particle swarm optimization algorithm is used to tune the 6-dimensional vector of the tuning parameters with multi-objective performance criteria. Numerical investigations have been carried out to check the performance of the proposed system under varying conditions of viscosity, clearance gap, external load and the spindle speed. The comparison of our results with the published literature shows the effectiveness of the proposed system.

scholarly journals ANALYTICAL METHODS FOR CALCULATING FAN AERODYNAMICS

2015 ◽  
Vol 55 (6) ◽  
pp. 373
Author(s):  
Jan Dostal ◽  
Jan Kuzel
Keyword(s):  
Mathematical Model ◽  
Analytical Methods ◽  
Preliminary Design ◽  
Computer Programme ◽  
Aerospace Research ◽  
Model Based ◽  
The Creation ◽  
The Mathematical Model ◽  
Measuring Unit

This paper presents results obtained between 2010 and 2014 in the field of fan aerodynamics at the Department of Composite Technology at the VZLÚ aerospace research and experimental institute in Prague – Letnany. The need for rapid and accurate methods for the preliminary design of blade machinery led to the creation of a mathematical model based on the basic laws of turbomachine aerodynamics. The mathematical model, the derivation of which is briefly described below, has been encoded in a computer programme, which enables the theoretical characteristics of a fan of the designed geometry to be determined rapidly. The validity of the mathematical model is assessed continuously by measuring model fans in the measuring unit, which was developed and manufactured specifically for this purpose. The paper also presents a comparison between measured characteristics and characteristics determined by the mathematical model as the basis for a discussion on possible causes of measured deviations and calculation deviations.

Movement Time to an Array of Controls

1993 ◽  
Vol 37 (9) ◽  
pp. 625-629 ◽  
Author(s):  
Errol R. Hoffmann
Keyword(s):  
Mathematical Model ◽  
Theoretical Result ◽  
Movement Time ◽  
Element Model ◽  
Optimum Control ◽  
Fitts Law ◽  
Model Based ◽  
Array Density

Two tasks in which subjects aim at an array of devices were considered: moving to one knob within an array and moving the finger on a numeric keypad. It was shown by a mathematical model based on Fitts' law, that when the array density is specified for the array of knobs or keys, there is an optimum control size for minimum movement time. The theoretical result was obtained by considering a two-element model of the movement, the first being a reach to the general location of the control and the second describing the insertion of the fingers into the space between adjacent controls. As the first element has a movement time that decreases with increase of control size and the second a time increasing with control size, there is an optimum control size where the movement time is a minimum.

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