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UPFC Control based on New IP Type Controller
Shirvani, Mojtaba,Keyvani, Babak,Abdollahi, Mostafa,Memaripour, Ahmad The Korean Institute of Electrical Engineers 2012 Journal of Electrical Engineering & Technology Vol.7 No.5
This paper presents the application of Unified Power Flow Controller (UPFC) in order to simultaneous control of power flow and voltage and also damping of Low Frequency Oscillations (LFO) at a Single-Machine Infinite-Bus (SMIB) power system installed with UPFC. PI type controllers are commonly used controllers for UPFC control. But for the sake of some drawbacks of PI type controllers, the scope for finding a better control scheme still remains. In this regard, in this paper the new IP type controllers are considered as UPFC controllers. The parameters of these IP type controllers are tuned using Genetic Algorithms (GA). Also a stabilizer supplementary controller based UPFC is considered for increasing power system damping. To show the ability of IP controllers, this controller is compared with classical PI type controllers. Simulation results emphasis on the better performance of IP controller in comparison with PI controller.
MONEY AND INFLATION : INTERNATIONAL EVIDENCE BASED ON COINTEGRATION THEORY
SHIRVANI, HASSAN,WILBRATTE, BARRY 한국국제경제학회 1994 International Economic Journal Vol.8 No.1
This study investigates the relationship between money and inflation using cointegration tests. For a broad sample of countries, the paper finds that most time series data underlying a typical monetarist model are nonstationary, indicating that it is necessary to appropriately transform the data in order to render the confidence tests reliable. Our principal finding is that money and inflation are related only in countries with high inflation. [E31]
Yazdan Shirvany,Oskar Talcoth,Mikael Persson,Tonny Rubæk,Fredrik Edelvik,Stefan Jakobsson 대한의용생체공학회 2013 Biomedical Engineering Letters (BMEL) Vol.3 No.1
Purpose The aim of this paper is to evaluate the performance of an EEG source localization method that combines a finite element method (FEM) and the reciprocity theorem. Methods The reciprocity method is applied to solve the forward problem in a four-layer spherical head model for a large number of test dipoles. To benchmark the proposed method, the results are compared with an analytical solution and two state-of-the-art methods from the literature. Moreover,the dipole localization error resulting from utilizing the method in the inverse procedure for a realistic head model is investigated with respect to EEG signal noise and electrode misplacement. Results The results show approximately 3% relative error between numerically calculated potentials done by the reciprocity theorem and the analytical solutions. When adding EEG noise with SNR between 5 and 10, the mean localization error is approximately 4.3 mm. For the case with 10 mm electrode misplacement the localization error is 4.8mm. The reciprocity EEG source localization speeds up the solution of the inverse problem with more than three orders of magnitude compared to the state-of-the-art methods. Conclusions The reciprocity method has high accuracy for modeling the dipole in EEG source localization, is robust with respect to noise, and faster than alternative methods.
UPFC Control based on New IP Type Controller
Mojtaba Shirvani,Babak Keyvani,Mostafa Abdollahi,Ahmad Memaripour 대한전기학회 2012 Journal of Electrical Engineering & Technology Vol.7 No.5
This paper presents the application of Unified Power Flow Controller (UPFC) in order to simultaneous control of power flow and voltage and also damping of Low Frequency Oscillations (LFO) at a Single-Machine Infinite-Bus (SMIB) power system installed with UPFC. PI type controllers are commonly used controllers for UPFC control. But for the sake of some drawbacks of PI type controllers, the scope for finding a better control scheme still remains. In this regard, in this paper the new IP type controllers are considered as UPFC controllers. The parameters of these IP type controllers are tuned using Genetic Algorithms (GA). Also a stabilizer supplementary controller based UPFC is considered for increasing power system damping. To show the ability of IP controllers, this controller is compared with classical PI type controllers. Simulation results emphasis on the better performance of IP controller in comparison with PI controller.
Quality of Life in Postmenopausal Female Members and Non-members of the Elderly Support Association
( Mina Shirvani ),( Mohammad Heidari ) 대한폐경학회 2016 대한폐경학회지 Vol.22 No.3
Objectives: The purpose of this study was to evaluate the quality of life (QOL) in postmenopausal members and non-members of the elderly support association in Borujen city, Iran. Methods: This study was a cross-sectional descriptive study being applied to the participants were postmenopausal women of over 55 years. Thus, 40 postmenopausal members of the elderly support association of Borujen city and 40 non-members were randomly selected. The 36 item short-form health survey (SF-36), with the 4 psychological, social, physical-movement, and environmental domains, was completed. Data were analyzed using SPSS software. Results: The mean total score of QOL of member of the association was significantly greater than non-members. Student`s t-test showed a significant relationship between QOL and membership of the association (P < 0.05). One-way analysis of variance (ANOVA) showed that the mean QOL of postmenopausal women, according to membership and marital status (P < 0.01), housing (P < 0.01), and underlying disease (P < 0.01), was statistically significant. Conclusions: According to the results, supportive measures, such as increasing the participation of the elderly in public life through proper preparations to join them and membership in peer groups such as support associations and non-governmental organizations (NGOs) can be greatly effective in improving QOL. The results showed that the QOL of the participants was at a moderate level and membership in support associations for the elderly was effected on the QOL in postmenopausal women. Moreover, considering the importance of the elderly in the community. (J Menopausal Med 2016;22:154-160)
Polyurethane/Poly(vinyl alcohol) Blend Membranes for Gas Separation
Hemmat Shirvani,Morteza Sadeghi,Hajar Taheri Afarani,Rouhollah Bagheri 한국섬유공학회 2018 Fibers and polymers Vol.19 No.5
This Study involves preparation and characterization of polyurethane (PU) and polyurethane/poly(vinyl alcohol) (PU/PVA) blend membranes for gas separation. PU was synthesized by two step polymerization based on isophorone diisocyanate (IPDI), 1,4-butanediamine (BDA), polytetramethylene glycol (PTMG) in the mole ratio of 3:2:1. The prepared blend membranes were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray Diffraction (XRD), and scanning electron microscopy (SEM). The effects of molecular weight of PVA, and blend composition on the gas transport properties of N2, O2, CO2 and CH4 were investigated. Obtained results show that the permeability of gases decreased in blend membranes by poly(vinyl alcohol) (PVA) molecular weights while their gas selectivity enhanced. Comparison of the gas separation performance of the prepared membranes to Robeson upper bound, reveal the enhancement of membrane performance by introducing PVA in PU matrix.
Asghar Shirvani,Mohammad Ali SHOGHALI 한국곤충학회 2010 Entomological Research Vol.40 No.4
A noctuid species, Eucoptocnemis tischendorfi (Püngeler, 1915) (Lepidoptera: Noctuidae), is first reported for the fauna of Iran and the female of Brachygalea miskoi Ronkay, 1997 is first described. Adults including genitalia of both species are illustrated.
Effect of cement stabilization on geotechnical properties of sandy soils
Shooshpasha, Issa,Shirvani, Reza Alijani Techno-Press 2015 Geomechanics & engineering Vol.8 No.1
An experimental program was performed to study the effects of cement stabilization on the geotechnical characteristics of sandy soils. Stabilizing agent included lime Portland cement, and was added in percentages of 2.5, 5 and 7.5% by dry weight of the soils. An analysis of the mechanical behavior of the soil is performed from the interpretation of results from unconfined compression tests and direct shear tests. Cylindrical and cube samples were prepared at optimum moisture content and maximum dry unit weight for unconfined compression and direct shear tests, respectively. Samples were cured for 7, 14 and 28 days after which they were tested. Based on the experimental investigations, the utilization of cemented specimens increased strength parameters, reduced displacement at failure, and changed soil behavior to a noticeable brittle behavior.