Islamic Azad University at West Tehran

www.wtiau.ac.ir
Tehran, Iran
SEARCH FILTERS
Time filter
Source Type

Sheikh Goodarzi M.,University of Tehran | Sakieh Y.,Gorgan University of Agricultural Sciences and Natural Resources | Navardi S.,Islamic Azad University at West Tehran
Geocarto International | Year: 2017

The present study adopts an integrative modelling methodology, which combines the strengths of the SLEUTH model and the Conservation Assessment and Prioritization System (CAPS) method. By developing a scenario-based geographic information system simulation environment for Hashtpar City, Iran, the manageability of the landscape under each urban growth scenario is analysed. In addition, the CAPS approach was used for biodiversity conservation suitability mapping. The SLEUTH model was implemented to generate predictive urban layers of the years 2020, 2030, 2040 and 2050 for each scenario (dynamic factors for conservation suitability mapping). Accordingly, conservation suitability surface of the area is updated for each time point and under each urban development storyline. Two-way analysis of variance and Duncan’s new multiple range tests were employed to compare the functionality of the three scenarios. Based on results, the managed urban growth scenario depicted better results for manageability of the landscape and less negative impact on conservation suitability values. © 2017 Informa UK Limited, trading as Taylor & Francis Group


Dargahi T.,Islamic Azad University at West Tehran | Javadi H.H.S.,Shahed University | Shafiei H.,University of Tehran
Wireless Personal Communications | Year: 2017

With the advances in technology, there has been an increasing interest both from research and industrial communities in the use of Underwater Wireless Sensor Networks (UWSNs). These networks are vulnerable to a wide class of security attacks. In fact, UWSNs are particularly more susceptible to attacks than their ground-base counterparts due to the challenges imposed by their deployment environment. This paper proposes a distributed approach to detect and mitigate routing attacks in such networks. An analytical model is provided to capture the interactions between various contributing parameters. Our simulation experiments validate the correctness and efficiency of the proposed approach. © 2017 Springer Science+Business Media New York


Siadatan A.,Islamic Azad University at West Tehran | Ghasemi S.,Shahid Beheshti University | Shamsabad Farahani S.S.,Shahid Beheshti University
International Journal of Engineering, Transactions A: Basics | Year: 2017

In this paper the method of sensorless startup of direct current brushless motor using third harmonic back Electromotive Force (EMF) and motor startup using microcontroller for pulse width modulation, power switch control and motor output analysis is presented which renders RPM control and high speed achievement for motor. The microcontroller is used for processor and metal-oxide semiconductor field-effect transistor (MOSFETs) are used for power circuit. Besides, the motor does not have any sensors to detect rotor position. Furthermore, the microcontroller modulates pulse width, controls power circuit and analyses motor output. The innovation in this research is that the third harmonic function is used for motor control and is compared with the Back-EMF force to recognize zero crossing. Moreover, N-type MOSFETs are used in power circuit high side and low side which are useful in the current rate of MOSFETs due to their similarities. Also, the IR2101 MOSFET drive is utilized for startup which improves the firing time of MOSFETs. Besides, using tantalum capacitors and putting resistor by the gate route of MOSFETs is efficient. Finally, experimental results are given to verify the validation of the proposed method. © 2017, Materials and Energy Research Center. All rights reserved.


Piri R.,Islamic Azad University at West Tehran | Kermani M.,Tehran University of Medical Sciences | Esrafili A.,Tehran University of Medical Sciences
Journal of Mazandaran University of Medical Sciences | Year: 2017

Background and purpose: Chlorophenol compounds are refractory and toxic contaminants that enter the environment as a result of industrial activities. They can contaminate water sources through leaking into the groundwater or being washed out from polluted soil. The aim of the present study was to evaluate the rate of 4-Chlorophenol (4-CP) degradation using the UV/NaPS process. Materials and methods: In this investigation, the photochemical oxidation process was conducted in a batch type laboratory-scale photoreactor (1.5 L) equipped with a 50000 μWS/Cm2 power. This study also investigated the effects of independent variables including sodium persulfate concentration (8.4-84 mmol/L), pH (3-10), 4-CP concentration (0.5.5 mmol/L), and reaction time (2-30 min) on the removal efficiency of 4-CP. The effluent concentration of 4-CP was measured by the UV-visible spectrophotometer at 280 nm wavelength. In addition, kinetic model was investigated. Results: The optimum removal efficiency of 4-C by UV/NaPS process was 89.3% with sodium persulfate concentration of 8.4 mmol/L, pH of 5, initial 4-CP concentration of 1.5 mmol/L, and reaction time of 30 min. Moreover, 60.4% of the total organic carbon (TOC) was removed under similar condition. In addition, the data was found to follow the first-order kinetics. Conclusion: Considering the growing use of UV radiation in water treatment processes and the considerable efficiency of UV/NaPS process in removing 4-CP, this method can be proposed for the elimination of 4-CP after performing cost-benefit analyses. © 2017, Mazandaran University of Medical Sciences. All rights reserved.


Khoshroo M.J.,Islamic Azad University at West Tehran | Fatemi O.,University of Tehran
CRIS 2010: Connecting Science with Society - The Role of Research Information in a Knowledge-Based Society - 10th International Conference on Current Research Information Systems | Year: 2010

The Supreme Council of Science, Research and Technology (SCSRT) of Iran which is headed by the presi-dent and consists of main decision makers of the country in research area including several ministers has ordered the development of a national current research information system, code named SEMAT, in the country in 2006. The main reasons of such system are to help top decision makers for research process in the country and also to help researchers to access scientific information. A group of representatives from SCRST is formed as the steering committee of SEMAT. For the first phase of the project, three sub-systems have been defined by the committee. In this paper the architecture of SEMAT and its main services are presented.


Siadatan A.,Islamic Azad University at West Tehran | Kazemi Karegar H.,Shahid Beheshti University | Najmi V.,Shahid Beheshti University
PECon2010 - 2010 IEEE International Conference on Power and Energy | Year: 2010

The high impedance fault detection in power system is one of the hard works and if the fault does not clear then the power system may get into damage. In this paper a new method for high impedance fault detection is proposed. The proposed method is based on the chaotic and doffing function. The paper will propose the appropriate formula and the setting parameters. The method is applied on a sample distribution network and the simulation results show that the new method properly works. ©2010 IEEE.


Siadatan A.,Islamic Azad University at West Tehran | Afjei E.,Shahid Beheshti University
International Review of Electrical Engineering | Year: 2012

The Switched Reluctance Motor (SRM) is a high speed; simple and robust structure motor with high output torque and no windings on its rotor. In this paper, a two-layer 6 by 4 switched reluctance motor is proposed and investigated. The motor is simulated employing 3D Finite Element Method (FEM) to realize the motor characteristics. The flux linkage and static torque profile of the motor as well as the flux density flow of the motor through the rotor, stator and shaft is extracted by the simulation results. Furthermore, the prototype of the motor is fabricated to determine the validity of the results obtaining from simulation. The experimental analysis is performed using one conventional SRM which is coupled to fabricated motor as a load. The setup provides torque-speed and torque-current characteristics of the motor the shape as well as the measurement of the motor are taken out. © 2012 Praise Worthy Prize S.r.l. - All rights reserved.


Babaei P.,Islamic Azad University at West Tehran
Proceedings of the 2010 International Conference on Signal and Image Processing, ICSIP 2010 | Year: 2010

This paper proposes an automatic vehicles counting, classification and tracking for identifying Traffic flows in an intersection which is a fundamental task for video surveillance in urban traffic management. In intelligent transportation systems (ITS), especially in field of urban traffic management, intersections monitoring is one of the critical and challenging tasks. Where, objects have different characteristics such as varying velocities, stop and go. Therefore it is necessary to use a hybrid scheme of adaptive background mixture model to learn background model faster and more accurately, instead of using single rate of adaptation, which is not adequate. The main focus of this paper is to analyze activities at intersection in number of traffic zones for counting and classifying vehicles and then tracking to extract traffic flows which assists in regulating traffic lights for using in smart cameras. Traffic zones definition in intersection video, based on trajectories clustering; greatly reduce the time and volume of computation. Smart camera's fundamental purpose is to efficiently reduce the transmission rate and also analyze an intersection scene and report statics and information of interest which is not an image. Ground-truth experiments with urban traffic sequences show that our proposed algorithm is very promising relative to results using other techniques. ©2010 IEEE.


Moghassemi H.R.A.,Islamic Azad University at West Tehran
Proceedings - 7th International Conference on Networked Computing and Advanced Information Management, NCM 2011 | Year: 2011

License Plate Recognition system (LPR) plays a significant role in many application such as access control, traffic control, and the detection stolen vehicles. A LPR system can be divided into the detection and recognition stages. For license plate detection, a proposal method with to phase is used. At the first phase regions of around plate is clip out by help of vertical and horizontal projections. Next accurate location of plate is recognizing by connected component analysis and clustering techniques. Due to the positioning of vehicle towards the camera, the rectangular of license plate can be rotated and skewed in many ways. So skew detection and correction is requiring after plate detection. In this study an efficient method is proposed to skew detection and recognition. Zernike and wavelet moments features with rotation and scale invariant property are used to recognition of license plate characters. Proposed algorithms are robust to the different lighting condition, view angle, the position, size and color of the license plates when running in complicated environment. The overall performance of success for the license plate achieves 93.54% when the system is used to the license plate recognition in various conditions. © 2011 AICIT.


Farhadian M.,Iranian Materials and Energy Research Center | Sangpout P.,Iranian Materials and Energy Research Center | Hosseinzadeh G.,Islamic Azad University at West Tehran
Journal of Energy Chemistry | Year: 2015

The shape of nanostructure has important effects on their properties, therefore in this study, we have prepared and characterized three different morphologies of WO3 nanostructures i.e. nanorod, nanosphere and nanoplate for surveying shape effect on their photocatalytic properties toward degradation of Rhodamine B (RhB) dye. Obtained results show that nanoplate WO3 in comparison with others has the best photocatalytic activity. According to SEM, and photocatalytic degradation results, the reason for this behavior is the sharp edges and corners of WO3 nanoplates. Because of their low coordination number, atoms located in the edges and corners of the WO3 nanoplates have more activity, adsorb more RhB and therefore give more photocatalytic activity to the WO3 nanoplates. Using of different scavengers showed that hydroxyl radicals are mainly responsible for photocatalytic activity of WO3 nanoplates and nanospheres but for WO3 nanorods, superoxide radicals are the main photocatalytic degradation agents. © 2015 Dalian Institute of Chemical Physics, the Chinese Academy of Sciences. Published by Elsevier B.V.

Loading Islamic Azad University at West Tehran collaborators
Loading Islamic Azad University at West Tehran collaborators