scholarly journals Mathematical model system of course mode gyro compass

2006 ◽  
Vol 28 (2) ◽  
Author(s):  
О.А. Сущенко
Keyword(s):  
Mathematical Model ◽  
Model System ◽  
Gyro Compass

A mathematical model to achieve sustainable forest management

2015 ◽  
Vol 06 (04) ◽  
pp. 1550040 ◽  
Author(s):  
A. K. Misra ◽  
Kusum Lata
Keyword(s):  
Mathematical Model ◽  
Sustainable Forest Management ◽  
Forest Products ◽  
Model System ◽  
Forest Resources ◽  
Genetically Engineered ◽  
Population Pressure ◽  
Nonlinear Mathematical Model ◽  
Modeling Process ◽  
Genetically Engineered Plants

Forest resources are important natural resources for all living beings but they are continuously depleting due to overgrowth of human population and their development activities. Therefore, conservation of forest resources is an important problem for sustainable development. In view of this, in this paper, we have proposed and analyzed a nonlinear mathematical model to study the effects of economic and technological efforts on the conservation of forest resources. In the modeling process, it is assumed that due to increase in population size, the demand of population (population pressure) for forest products, lands, etc., increases and to reduce this population pressure, economic efforts are employed proportional to the population pressure. Further, it is assumed that technological efforts in the form of genetically engineered plants are applied proportional to the depleted level of forest resources to conserve them. Model analysis reveals that increase in economic and technological efforts increases the density of forest resources but further increase in these efforts destabilizes the system. Numerical simulation is carried out to verify analytical findings and explore the effect of different parameters on the dynamics of model system.

Instability and Mitotic Patterns in Tissue Growth

1973 ◽  
Vol 95 (3) ◽  
pp. 324-327 ◽  
Author(s):  
Leon Glass
Keyword(s):  
Mathematical Model ◽  
Tumor Growth ◽  
Mitotic Activity ◽  
Model System ◽  
Tissue Growth ◽  
Dimensionless Number

A mathematical model which reproduces several qualitative features of cancerous tumor growth is proposed. The onset of unstable growth is characterized by a dimensionless number, which is defined in terms of the parameters describing the system. Patterns of mitotic activity of the model system are compared with experimentally observed patterns of mitotic activity in cancerous tissues.

scholarly journals Impact of Hygiene on Malaria Transmission Dynamics: A Mathematical Model

2021 ◽  
Author(s):  
Temidayo Oluwafemi ◽  
Emmanuel Azuaba
Keyword(s):  
Mathematical Model ◽  
Malaria Transmission ◽  
Basic Reproduction Number ◽  
Human Population ◽  
Reproduction Number ◽  
Model System ◽  
Transmission Dynamics ◽  
The Impact ◽  
Disease Free ◽  
The Basic Reproduction Number

Malaria continues to pose a major public health challenge, especially in developing countries, 219 million cases of malaria were estimated in 89 countries. In this paper, a mathematical model using non-linear differential equations is formulated to describe the impact of hygiene on Malaria transmission dynamics, the model is analyzed. The model is divided into seven compartments which includes five human compartments namely; Unhygienic susceptible human population, Hygienic Susceptible Human population, Unhygienic infected human population , hygienic infected human population and the Recovered Human population  and the mosquito population is subdivided into susceptible mosquitoes  and infected mosquitoes . The positivity of the solution shows that there exists a domain where the model is biologically meaningful and mathematically well-posed. The Disease-Free Equilibrium (DFE) point of the model is obtained, we compute the Basic Reproduction Number using the next generation method and established the condition for Local stability of the disease-free equilibrium, and we thereafter obtained the global stability of the disease-free equilibrium by constructing the Lyapunov function of the model system. Also, sensitivity analysis of the model system was carried out to identify the influence of the parameters on the Basic Reproduction Number, the result shows that the natural death rate of the mosquitoes is most sensitive to the basic reproduction number.

scholarly journals The Dynamic of Heterosexual Transmission of HIV-AIDS Model with Treatment

2017 ◽  
Vol 6 (2) ◽  
Author(s):  
Kehinde Adekunle Bashiru
Keyword(s):  
Mathematical Model ◽  
Equilibrium Points ◽  
Model System ◽  
Transmission Dynamics ◽  
Heterosexual Transmission ◽  
Asymptotically Stable ◽  
Effect Of Treatment ◽  
The Impact ◽  
Disease Free ◽  
Hiv Aids

A Mathematical Model of HIV/AIDS with Heterosexual transmission in the presence of treatment was examine in this paper, it ascertained the impact of treated individuals on the transmission dynamics of HIV/AIDS. Equilibrium points of the model system were found, stability analysis and numerical simulation were carried out, it was discovered that HIV/AIDS can die out with test of time as Ro < 1 . It was observed that the model had a disease free equilibrium which was asymptotically stable for Ro < 1 and unstable for Ro > 1. Graphical representations of the numerical analysis showing the effect of treatment on the model were also presented.

Constant-Speed Oscillation of a Pump Turbine Observed on a Pumped-Storage Model System

2019 ◽  
Vol 141 (5) ◽  
Author(s):  
Jinhong Hu ◽  
Jiandong Yang ◽  
Wei Zeng ◽  
Jiebin Yang
Keyword(s):  
Mathematical Model ◽  
Characteristic Curve ◽  
Model System ◽  
Constant Speed ◽  
Negative Slope ◽  
Maximum Deviation ◽  
Pump Turbine ◽  
Storage Model ◽  
Oscillation Process ◽  
Pumped Storage

The hydraulic characteristics of pump turbines in off-design conditions, especially the S-shaped characteristics, are crucial for the safety and stability of the unit. To explore the S-characteristics of pump turbines through a transient method, an experimental investigation was conducted based on a pumped-storage model system at Wuhan University. By shutting down the circulating pump, a special transient process was triggered, forcing the pump turbine to operate in turbine mode, turbine brake mode, and reverse rotational pump mode. As the rotational speed of the pump turbine was maintained almost constant in the oscillation process with a maximum deviation of 0.6%, this transient operation was named as constant-speed oscillation (CSO). The parameters for global performance and pressure pulsations in the vaneless gap were measured and analyzed. In addition, the one-dimensional rigid column theory was used to establish a mathematical model for simulation. The results from simulation were quantitatively compared with the experimental results. Finally, the reason for the CSO was theoretically explained based on stability analysis through the established mathematical model. It was observed that the positive slope of ned–Qed characteristic curves at no-flow resulted in this oscillation. In contrast, the simulation was performed under the same conditions with a modified ned–Qed characteristic curve, which had a negative slope at no-flow. However, the results showed that, with the modified characteristic curve, the pump turbine would stabilize at no-flow.

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