scholarly journals Lump, its interaction phenomena and conservation laws to a nonlinear mathematical model

Author(s):  
Abdullahi Yusuf ◽  
Tukur Abdulkadir Sulaiman ◽  
Evren Hincal ◽  
Dumitru Baleanu
2021 ◽  
Author(s):  
Xiao-Zhong Zhang ◽  
Abdullahi Yusuf ◽  
Tukur Abdulkadir Sulaiman ◽  
Mustafa Inc ◽  
Dumitru Baleanu ◽  
...  

2020 ◽  
Vol 16 (32) ◽  
pp. 195-223
Author(s):  
Edgardo Pérez

In this paper, we present a nonlinear mathematical model, describing the spread of high-risk alcohol consumption behavior among college students in Colombia. We proved the existence and stability of the alcohol-free and drinking state equilibrium by means of Lyapunov function and LaSalle’s invariance principle. Also, we apply optimal control to study the impact of a preventive measure on the spread of drinking behavior among college students. Finally, we use numerical simulations and available data provided by the United Nations Office on Drugs and Crime (UNODC) and the Colombian Ministry of Justice to validate the obtained mathematical model.


2005 ◽  
Vol 49 (02) ◽  
pp. 69-79 ◽  
Author(s):  
Ming-Chung Fang ◽  
Jhih-Hong Luo ◽  
Ming-Ling Lee

In the paper, a simplified six degrees of freedom mathematical model encompassing calm water maneuvering and traditional seakeeping theories is developed to simulate the ship turning circle test in regular waves. A coordinate system called the horizontal body axes system is used to present equations of maneuvering motion in waves. All corresponding hydrodynamic forces and coefficients for seakeeping are time varying and calculated by strip theory. For simplification, the added mass and damping coefficients are calculated using the constant draft but vary with encounter frequency. The nonlinear mathematical model developed here is successful in simulating the turning circle of a containership in sea trial conditions and can be extended to make the further simulation for the ship maneuvering under control in waves. Manuscript received at SNAME headquarters February 19, 2003; revised manuscript received January 27, 2004.


Author(s):  
V.P. Ivanov

The article deals with the problem of synthesis of terminal control. A functional, a nonlinear mathematical model of a dynamic object, restrictions on the maximum permissible values of control are given. The control law is synthesized. The following statement is proved: the synthesis of the optimal control is carried out using the entire initial mathematical model of the dynamical object, but to calculate the control at any particular moment of time, it is possible to use a reduced (truncated) model, which simplifies the computational algorithms. Thus, there is an informational dualism of the manage- ment task. The approach is an extension of the principle of information redefinition of Yu.B. Germeier to the area of optimal terminal control.


Author(s):  
Mohammed Hajeeh

Repairable systems are either repaired perfectly to a state of as good as new or imperfectly. In this work, a system which undergoes imperfect repair is investigated. A nonlinear mathematical model is formulated for a system with the objective of finding the optimum failure and repair rate with the minimum costs subject to attaining a pre-specified performance level. Two imperfect repair models are examined. In the first model, the system is replaced by a new one after several failures. In the second model, the system is either replaced with a specific probability (1-p) or is imperfectly repaired after each failure with probability p. The optimal solution is presented in a closed form expression.


1987 ◽  
Vol 33 (5) ◽  
pp. 658-660 ◽  
Author(s):  
C Dotti ◽  
G P Ceda ◽  
L Denti ◽  
S Cavalieri ◽  
G Borasi ◽  
...  

Abstract To correct the results of a radioimmunoassay for beta-thyrotropin (TSH) subunit by eliminating the proportion ascribable to intact TSH, we have devised a method that experimentally reproduces the conditions under which the interference develops. Beta-TSH subunit was assayed in several preparations containing known concentrations of both beta-TSH and TSH. The TSH-induced overestimation of beta-TSH was linearly related to the concentration of antigen in the sample. At a constant concentration of TSH, therefore, the following equation is applicable: F = aE + b, where F is the measured (but overestimated) concentration of beta-TSH, E is the actual concentration of beta-TSH, and a and b are the slope and the intercept of the regression line, respectively. a and b, once expressed as a function of TSH, allow the correction of the overestimation. The analysis of the results according to the mass action and conservation laws shows that the antiserum is more avid for the interferent (intact TSH) than for the antigen (beta-TSH).


Author(s):  
A. K. Misra ◽  
Kusum Lata

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.


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