Entity

Time filter

Source Type


Ayati M.,University of Tehran | Bakhtiyari A.,Alborz institute of higher education | Gohari A.,Alborz institute of higher education
2016 4th International Conference on Control, Instrumentation, and Automation, ICCIA 2016 | Year: 2016

Boost convertor is utilized to increase amplitude of DC voltage with a high efficiency. In order to reach a desired output voltage, converter parameters are changed accordingly. These variations in the reference current may cause chaos and bifurcation in convertor dynamics which disrupt convertor functionality. This paper presents a new fuzzy delayed-feedback chaos controller for controlling boost converter. Using fuzzy controller improves the value of the inductor current and output of the converter. The resulted controller is also robust to small parameter variations of converter. © 2016 IEEE. Source


Ayati M.,University of Tehran | Bakhtiyari A.,Alborz institute of higher education | Gohari A.,Alborz institute of higher education
2016 4th International Conference on Control, Instrumentation, and Automation, ICCIA 2016 | Year: 2016

In this paper, a new fuzzy delayed-feedback controller is developed to eliminate chaotic behavior of buck converter. Here, the impact of initial parameters is studied on the chaos occurrence. Chaotic region borders and bifurcation diagram are drawn for the buck converter. In order to control chaos when the operating point is in the chaotic region, a delayed-feedback controller is used. Moreover, to have a stable and robust closed-loop system in the presence of reference voltage changes, a supervisory fuzzy logic controller is utilized to determine the parameters of delayed-feedback controller. Overall controller is called fuzzy delayed-feedback controller. It has been confirmed through simulations that proposed scheme increases efficiency and flexibility of the buck converter. © 2016 IEEE. Source


Shivanian E.,Imam Khomeini International University | Rahimi A.,Alborz institute of higher education | Hosseini M.,Alborz institute of higher education
International Journal of Computer Mathematics | Year: 2015

In this article, the meshless local radial point interpolation (MLRPI) method is applied to simulate three-dimensional wave equation subject to given appropriate initial and Neumann's boundary conditions. The main drawback of methods in fully 3-D problems is the large computational costs. In the MLRPI method, all integrations are carried out locally over small quadrature domains of regular shapes such as a cube or a sphere. The point interpolation method with the help of radial basis functions is proposed to form shape functions in the frame of MLRPI. The local weak formulation using Heaviside step function converts the set of governing equations into local integral equations on local subdomains where Neumann's boundary condition is imposed naturally. A two-step time discretization technique with the help of the Crank-Nicolson technique is employed to approximate the time derivatives. Convergence studies in the numerical example show that the MLRPI method possesses reliable rates of convergence. © 2015 Taylor & Francis Source


Karbalaei M.,Islamic Azad University at Tehran | Norouzi A.,Islamic Azad University at Tehran | Hosein Abadi B.F.,Islamic Azad University at Qazvin | Malmir R.,Alborz institute of higher education | Taheri F.,Alborz institute of higher education
Research Journal of Applied Sciences, Engineering and Technology | Year: 2013

The purpose of this study focuses on the relationship between product involvement and consumer risk perception. More specifically, the findings from the empirical study generally support the research hypotheses and the motivational process model of product involvement and consumer risk perception. The subjects were 380 of the potential buyers of cars in BGs' (Bahman Group) dealer in Tehran. Structural Equation Modeling (SEM) with Lisrel software was used for the data analysis. This study present a conceptual motivational process model, explicating the processes by which involvement and consumer risk perception are caused and influence one another, as well as subsequent behavioral responses of consumer. An empirical study, carry out to test the motivational process model and hypothesized casual relationships find overall support. © Maxwell Scientific Organization, 2013. Source

Discover hidden collaborations