Amirkabir University of TechnologyAUT Journal of Electrical Engineering2588-291041120090401A Micropower Multi Decade Dynamic Range Current-Mode True RMS-to-DC ConverterA Micropower Multi Decade Dynamic Range Current-Mode True RMS-to-DC Converter11027210.22060/eej.2009.272ENEbrahimFarshidiiE. Farshidi is a Faculty Member of the Department of Electrical Engineering, Shahid Chamran University of Ahvaz, Ahvaz, Iran (e-mail:
farshidi@scu.ac.ir).Sayed MasoudSayediiiS. M. Sayedi is a Faculty Member of the Department of Electrical and Computer Engineering, Isfahan University of Technology, Isfahan, Iran (email:
m_sayedi@cc.iut.ac.ir).Journal Article20140317A log-domain current-mode true RMS-to-DC converter based on a novel synthesis of a simplified current-mode low pass filter and a two-quadrant squarer/divider is presented. The circuit employs floating gate MOS (FG-MOS) transistors operating in weak inversion region. The converter features low power(<1.5uW), low supply voltage (0.9V), two quadrant input current, immunity from body effect, low circuit complexity, and very wide input dynamic range(0.7nA to 350nA). Simulation results by HSPICE show high performance of the circuit and confirm the validity of the proposed technique.https://eej.aut.ac.ir/article_272_7a614fd06c325499f1680b9896beedeb.pdfAmirkabir University of TechnologyAUT Journal of Electrical Engineering2588-291041120090401A Novel Subsampling Method for 3D Multimodality Medical Image Registration Based on Mutual InformationA Novel Subsampling Method for 3D Multimodality Medical Image Registration Based on Mutual Information111927310.22060/eej.2009.273ENMaryamZibaeifardiMaryam Zibaeifard is with Department of Computer Engineering and Information Technology, Amirkabir University of Technology, Tehran,
Iran (email: zibaeifard@ce.aut.ac.ir).MohammadRahmatiiiMohammad Rahmati is with Department of Computer Engineering and Information Technology, Amirkabir University of Technology, Tehran,
Iran (email: rahmati@aut.ac.ir), Corresponding author.Journal Article20140317Mutual information (MI) is a widely used similarity metric for multimodality image registration. However, it involves an extremely high computational time especially when it is applied to volume images. Moreover, its robustness is affected by existence of local maxima. The multi-resolution pyramid approaches have been proposed to speed up the registration process and increase the accuracy of the result. In this paper, we present a new improved method of sample selection for multi-stage registration based on mutual information. Instead of down-sampling of the whole image as it is done in the pyramid methods, we propose a new technique to find a suitable subset of image samples based on image information content, which results in a better estimate of the optimal transformation. A comparison for MR images indicates that our proposed method yields better registration than subsampling method, especially when subsampling factor is low. The experimental results involving three-dimensional clinical images of CT, MR and PET are presented for rigid registration.https://eej.aut.ac.ir/article_273_4734ba6f3de83d861c3176a6273cac6d.pdfAmirkabir University of TechnologyAUT Journal of Electrical Engineering2588-291041120090401Development of an Analytic Model for Flux Switching MotorsDevelopment of an Analytic Model for Flux Switching Motors212927410.22060/eej.2009.274ENMohammadMardanehiM. Mardaneh and M. Mirsalim (IEEE Senior Member) are with the Department of Electrical Engineering, Amirkabir University of Technology,
Tehran, Iran (Email: m_mardaneh@aut.ac.ir).MojtabaMirsalimiiM. Mirsalim is also with the Department of Electrical Engineering, San Antonio, TX, 78228 (e-mail: mmirsalim@stmarytx.edu).Journal Article20140317This paper presents developing an analytical model for flux switching motors. The motor is a class of variable reluctance motors that has two windings on stator; a field winding and an armature winding. Due to saliency of both stator and rotor poles, accurate modeling is difficult which arises from the nonlinear behavior of the machine. This paper presents a simple model which is able to predict the motor inductances. The advantage of this method is that it describes the parameters of motor based on its dimensions. The model predicts both the self and mutual inductances. In comparison with similar studies, the proposed model predicts the mutual-inductance of a flux switching motor very accurately. It should be noted that the mutual-inductance has not previously been considered by others in their analytic modeling of variable reluctance motors. The predicted results computed by the proposed analytic model are compared to that obtained by the two-dimensional finite element analysis.https://eej.aut.ac.ir/article_274_d947bf06a885db0d477d707121934ff8.pdfAmirkabir University of TechnologyAUT Journal of Electrical Engineering2588-291041120090401Cerebrospinal Pulsation Hydrodynamics in a 2D Simulation of Brain VentriclesCerebrospinal Pulsation Hydrodynamics in a 2D Simulation of Brain Ventricles313627510.22060/eej.2009.275ENN.MasoumiiN. Masoumi is with the Department of Chemical and Petroleum Engineering, Sharif University of Technology, Tehran, Iran (e-mail:
masoomy@mehr.sharif.edu)D. BastaniD. Bastani is with the Department of Chemical and Petroleum Engineering, Sharif University of Technology, Tehran, Iran (e-mail:
bastani@sharif.edu)S.NajarianS. Najarian is with the Robotic Surgery and Artificial Tactile Sensing Laboratory, Faculty of Biomedical Engineering, Amirkabir University of
Technology, Tehran, Iran (email: najarian@aut.ac.ir)F.FarmanzadF. Farmanzad is with the Department of Mechanical Engineering, Iran University of Science and Technology, Tehran, Iran (email:
Farmanzad@iust.ac.ir)A.M.SeddighiA. M. Seddighi is with the Medical Science Department, Shahid Beheshti University, Tehran, Iran (email: Invincible19152@gmail.com)Journal Article20140317In this article, dynamics of the cerebrospinal fluid (CSF) was studied, using computational fluid dynamics. Using MRI images of two special cases, a 2-dimensional model of the ventricular system was made. CSF velocity and pressure distribution in ventricular system have high importance since the flow pattern of this liquid has an important effect on intracranial pressure, i.e., ICP, which has a key role in treatment of patients suffering from brain trauma. The pulsatile nature of CSF production, which is a result of arterial blood pressure in choroid plexuses, is considered for the first time. Finite element analysis of ventricular area with CFD analyzer software was processed using ADINA 8.2. Pressure distribution in different conditions of CSF production, i.e., constant input flow rate and pulsatile input flow rate, were compared. Comparison between the simulation results and reported experimental data depicted that modeling CSF with pulsatile production nature is more realistic. https://eej.aut.ac.ir/article_275_63923f49e5241343aa7acb6a06a751e7.pdfAmirkabir University of TechnologyAUT Journal of Electrical Engineering2588-291041120090401Nonlinear Modeling, Analysis and Design of an Active Antenna in S Frequency BandNonlinear Modeling, Analysis and Design of an Active Antenna in S Frequency Band374327610.22060/eej.2009.276ENP.TakookiP. Takook is with the Microwave/mm-Wave& Wireless Communication Research Lab, Radio Communication Center of Excellence,A.AbdipouriiA. Abdipour. is with the Department of Electrical Engineering, Amirkabir University of Technology, Tehran, Iran (e-mail: abdipour@aut.ac.ir).G.MoradiiiiG. Moradi. is with the Department of Electrical Engineering, Amirkabir University of Technology, Tehran, Iran (e-mail: ghmoradi@aut.ac.ir).A.TavakoliivA. Tavakoli. is with the Department of Electrical Engineering, Amirkabir University of Technology, Tehran, Iran (e-mail: tavakoli@aut.ac.ir)Journal Article20140317An active antenna for transmitter application in S frequency band is designed and analyzed using harmonic balance technique which is based on the nonlinear model of active devices. In this active antenna, the amplifier is integrated with the radiator which is a rectangular patch antenna. This patch antenna is analyzed employing full-wave momentum method. By applying nonlinear model of transistor in the amplifier and separating the linear and nonlinear parts, the harmonic balance equation is obtained. The splitting algorithm is applied to solve the harmonic balance equation and obtain the steady-state voltages at common port. The results of this method are compared with those of commercial simulators.https://eej.aut.ac.ir/article_276_db8e1af0cb3aca1ae2d0018624204529.pdfAmirkabir University of TechnologyAUT Journal of Electrical Engineering2588-291041120090401A Novel Active Filter for Mitigation of EMI and Other Adverse Effects of PWM Inverter-Fed AC MotorA Novel Active Filter for Mitigation of EMI and Other Adverse Effects of PWM Inverter-Fed AC Motor455327710.22060/eej.2009.277ENAbdolrezaEsmaeliiDr. A. Esmaeli is with the Reactors and Accelerators Research and Development School, Nuclear Science & Technology Research Institute, P.O
Box. 14155-1339, Tehran, Iran (e-mail: aesmaeli@aeoi.org.ir , esmaili20@yahoo.com).Journal Article20140317This paper presents novel active filter for mitigation electromagnetic interference (EMI) and other adverse effects of pulse width modulation (PWM) inverter-fed AC motor system. An active filter proposed and devised for this system is characterized by sophisticated connection of two small separate filters, capable of mitigating all the adverse effects. This paper provides high frequency models of PWM inverter, rectifier, DC link, induction motor and long cable. The configuration and design procedure of the proposed filter is presented.The whole system is modeled and simulated by commercially available simulation software. A practical system with EMI measurement system have been suggested to test designed equipment ability in emitting EMI and other adverse effects to comply with electromagnetic compatibility (EMC) standards. The simulation results are verified by experimental results, which show the reduction characteristics of the shaft voltage, bearing current, common mode current, leakage current and EMI.<span> </span>https://eej.aut.ac.ir/article_277_20f07591c6fcb220ffe637cda29bb3f6.pdfAmirkabir University of TechnologyAUT Journal of Electrical Engineering2588-291041120090401A Fast Localization and Feature Extraction Method Based on Wavelet Transform in Iris RecognitionA Fast Localization and Feature Extraction Method Based on Wavelet Transform in Iris Recognition556227810.22060/eej.2009.278ENSamiraKooshkestaniiS. Kooshkestani is with the engineering department, Shahed University, Tehran, Iran (e-mail:Samira_mis@yahoo.com),HamedSadjediiiH. Sadjedi is with the engineering department, Shahed University, Tehran, Iran (e-mail:sadjedi@shahed.ac.irMohammadPooyaniiiM. Pooyan is with the Engineering Department, Shahed University, Tehran, Iran (e-mail:pooyan@shahed.ac.i)Journal Article20140317With an increasing emphasis on security, automated personal identification based on biometrics has been receiving extensive attention. Iris recognition, as an emerging biometric recognition approach, is becoming a very active topic in both research and practical applications. In general, a typical iris recognition system includes iris imaging, iris liveness detection, and recognition. This research focused on the last issue and describes a new scheme for iris recognition. This paper proposes a new method to find the inner boundary of the Iris for localizing its area in the eye images. The proposed method besides having higher speed and lower calculation cost and simplicity, has got an acceptable precision for internal boundary localizing the proposed algorithm for feature extraction, characterizing the important information via biorthogonal wavelet and experimental results show that the proposed method has an encouraging performance.https://eej.aut.ac.ir/article_278_07cdfd23373b17c6b337251c22b7ea57.pdf