Mathematical model and computer simulations of telomere loss

2019 ◽  
Vol 465 ◽  
pp. 78-89 ◽  
Author(s):  
Ana Martinčić Špoljarić ◽  
Ivica Rubelj ◽  
Miljenko Huzak
Keyword(s):  
Mathematical Model ◽  
Computer Simulations ◽  
Telomere Loss

scholarly journals Effectiveness of a salt transport cascade in the renal medulla: computer simulations

1987 ◽  
Vol 252 (6) ◽  
pp. F1095-F1102 ◽  
Author(s):  
P. Lory
Keyword(s):  
Mathematical Model ◽  
Active Transport ◽  
Computer Simulations ◽  
Renal Medulla ◽  
Salt Transport ◽  
Countercurrent System ◽  
Federation Proc

Based on morphological observations, it has been concluded that the upper parts of the long descending limbs of Henle's loops should be able to secrete salts into the tubular fluid (Kriz, W. Federation Proc. 42:2379-2385, 1983). In the same article, a hypothesis is given depicting how this active transport in concert with certain characteristics of the medullary architecture might produce a transport cascade toward the papillary tip, thus supporting the accumulation of salts in this region. The effectiveness of the proposed mechanism can be judged by a mathematical model only. The computer simulations of the present study demonstrate that this mechanism indeed leads to an increase of the concentrating capability of the renal countercurrent system.

scholarly journals The charge percolation mechanism and simulation of Ziegler-Natta polymerizations, Part VII: Effects of the distribution of chromium active centers on silica on the polymerization of ethylene

2008 ◽  
Vol 73 (1) ◽  
pp. 97-111 ◽  
Author(s):  
Dragoslav Stoiljkovic ◽  
Branka Pilic ◽  
Misa Bulajic ◽  
Nebojsa Djurasovic ◽  
Nikolaj Ostrovskii
Keyword(s):  
Mathematical Model ◽  
Transition Metal ◽  
Induction Period ◽  
Computer Simulations ◽  
Chromium Oxide ◽  
Silica Surface ◽  
Chromium Concentration ◽  
Active Centers ◽  
Metal Compounds ◽  
Surface Discontinuity

The charge percolation mechanism (CPM) of olefin polymerization in the presence of transition metal compounds has been applied to explain the polymerization of ethylene by silica supported chromium oxide. In the previous work of this series, the fundamental issues and mechanism of this polymeri?zation were presented. In this work the compatibility of the CPM with the em?pirical findings is confirmed. The CPM has been applied to explain: the appea?rance of an induction period; the deactivation of active centers and the forma?tion of oligomers; the effects of chromium concentration on the silica surface, the silica surface discontinuity and the pore size of silica on polymerization and the formation of the structure of polyethylene. A mathematical model has been derived to explain the effects of the CrOx/SiO2 ratio on the productivity of Phil?lips catalysts in the polymerization of ethylene. The empirical findings have also been confirmed by computer simulations.

Fuzzy Track-Keeping Steering Design for a Precise Control of the Ship

2013 ◽  
Vol 196 ◽  
pp. 140-147 ◽  
Author(s):  
Józef Małecki
Keyword(s):  
Mathematical Model ◽  
Fuzzy Logic ◽  
Fuzzy Control ◽  
Computer Simulations ◽  
Control Law ◽  
Intelligence Gathering ◽  
Precise Control ◽  
Counter Measures ◽  
Command Signals ◽  
The Military

In this paper we design the fuzzy logic autopilot to precise control and a track-keeping control of the ship. Precise control of ship has known an increasing interest in the last years. The main benefits of usage of autopilot for control of ship can be removing a man from the dangers of the undersea environment and reduction in cost of exploration of deep seas. Currently, it is common to use the special ship to accomplish missions as the inspection of coastal and off-shore structures, cable maintenance, as well as hydrographical surveys. In the military field they are employed in such tasks as surveillance, intelligence gathering, torpedo recovery and mine counter measures. Hence, a problem of its ability to move along a reference path and keep a desired orientation is regarded. A non-linear mathematical model describes the vehicle’s dynamics. Command signals are generated by an autopilot with fuzzy control law implemented. Some results of computer simulations are provided to demonstrate effectiveness, correctness and usefulness of the approach.

scholarly journals Reliability model of the RTC System with trackside equipment equipped with a Peltier cell

2020 ◽  
Vol 2 (2) ◽  
pp. 98-108
Author(s):  
Rafał Kowalik ◽  
Emil Sadowski
Keyword(s):  
Mathematical Model ◽  
Control Systems ◽  
Computer Simulations ◽  
Traffic Control ◽  
System Simulation ◽  
Reliability Model ◽  
Electronic Components ◽  
Component Failure ◽  
Rail Vehicle ◽  
Railway Tracks

The article presents a mathematical model assessing the reliability of rail traffic control systems with a mounted Peltier cell. The semiconductor element will be used for operating electronic components that are in the trackside equipment. In the prepared model, Markow processes were used to describe the states occurring between individual components of the RTC System. Simulation tests were mainly based on determining the average time of component failure. The presented results were carried out for 1,000, 2,000 and 3,000 rail vehicle crossings over the railway tracks equipped with RTC Systems. At the very end of the article the conclusions resulting from computer simulations were presented.

Influence of Density-Dependent Migration on Two Competitive Populations between Patches in Manufacturing Engineering

2011 ◽  
Vol 323 ◽  
pp. 247-251
Author(s):  
Zhi Qiang Ye ◽  
Xu Zhang
Keyword(s):  
Mathematical Model ◽  
Interspecific Competition ◽  
Computer Simulations ◽  
Positive Equilibrium ◽  
Density Dependent ◽  
Migration Rates ◽  
Manufacturing Engineering ◽  
Globally Stable ◽  
Two Populations

A mathematical model of two competitive populations with migrations between two patches in manufacturing engineering is proposed. It is assumed that migration rates of the two populations are not constants but density-dependent which are led mainly by the pressure from interspecific competition. Conditions for the persistence of the system are obtained which shows that appropriate migration rates facilitate the two competitive populations to cooperate well such that both the populations are persistent in every patch. The results are confirmed by computer simulations. It is also found that the positive equilibrium which is globally stable changes into bitable equilibrium as the parameters vary.

Persistence and Extinction of One-Prey and Two-Predators System

2004 ◽  
Vol 9 (4) ◽  
pp. 307-329 ◽  
Author(s):  
B. Dubey ◽  
R. K. Upadhyay
Keyword(s):  
Mathematical Model ◽  
Growth Rate ◽  
Global Stability ◽  
Computer Simulations ◽  
Local Stability ◽  
Ratio Dependent

In this paper, a mathematical model is proposed and analysed to study the dynamics of one-prey two-predators system with ratio-dependent predators growth rate. Criteria for local stability, instability and global stability of the nonnegative equilibria are obtained. The permanent co-existence of the three species is also discussed. Finally, computer simulations are performed to investigate the dynamics of the system.

scholarly journals Effect of Gravity on the Kinetics of Consolidation of Powder Bodies

2003 ◽  
Vol 35 (3-4) ◽  
pp. 291-304
Author(s):  
R. M. Kadushnikov ◽  
E. Y. Nurkanov ◽  
A. V. Shak ◽  
M. S. Petrov ◽  
V. V. Kartashov
Keyword(s):  
Mathematical Model ◽  
Computer Simulations ◽  
Sintering Kinetics ◽  
Sintered Glass ◽  
Kinetics Of

Physical mathematical model of sintering powders is suggested with respect to the influence of gravitation on sintering kinetics. Structure genesis and evolution in sintered glass-based particulate bodies is investigated both in computer simulations and “in situ”.

Study on Centering Technology of Two Large-Scale Rotating Machinery Coupling Shaft Axis

2012 ◽  
Vol 550-553 ◽  
pp. 3108-3112
Author(s):  
Qin Li ◽  
Fu Bao Li ◽  
Zhong Ke Li
Keyword(s):  
Mathematical Model ◽  
Computer Simulations ◽  
Large Scale ◽  
Rotating Machinery ◽  
Plane Mirror ◽  
Position Sensitive ◽  
Theoretical Results

This paper studies the centering accuracy of two large-scale rotating machinery coupling shaft. Laser LD and position sensitive sensors PSD are used to measure and adjust the centering of two shaft coupling, through the analysis of LD-double-PSD-angle prism, LD-double-PSD-plane mirror of the double LD-double-PSD, dual-LD-double PSD centering program, it established a double LD-double -PSD system mathematical model, and the computer simulations to get good results. Based on the theoretical results, the two axes large-scale rotating machinery LD-link LD-double-PSD centering system has been studied and designed.

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