Fa
  • Ph.D. (1988)

    Electrical Engineering - Electronics

    , England, England

  • B.Sc. (1980)

    Electrical Engineering - Electronics

    , Amirkabir University of Technology,

    Data not found

    Contact

    Curriculum Vitae (CV)

    Aberration detection of pertussis from the Mazandaran province, Iran, from 2012 to 2018: Application of discrete wavelet transform

    Yousef Alimohamadi, Seyed Mohsen Zahraei, Manoochehr Karami, Mehdi Yaseri, Mojtaba Lotfizad, Kourosh Holakouie-Naieni
    Journal PaperJournal of Acute Disease , Volume 9 , Issue 3, 2020 May 1, {Pages 114 }

    Abstract

    Objective: To define the level of alarm threshold for pertussis aberrations and to detect the aberrations of the reported suspected cases of pertussis from the Mazandaran province in the north of Iran.Methods: The included cases were composed of the suspected pertussis patients who came from Mazandaran province and registered in the Center for Disease Control and Prevention from 20 March 2012 to 20 March 2018. A discrete wavelet transform-based method was used to detect the aberrations. All analyses were performed using MATLAB Software version 2018a and Excel 2010.Results: A total of 1 162 cases were recruited in the study, including 545 (46.90%) males and 617 (53.10%) females, with median age of 1.47 (0.22-9.56) years. The median age of ma

    Timely detection of Pertussis outbreaks in Iran: The comparison performance of Wavelet-based outbreak detector, Exponential weighted moving average, and Poisson regression?…

    K Holakouie-Naieni, Y Alimohamadi, SM Zahraei, M Karami, M Yaseri, M Lotfizad
    Journal Paper , 2020 February 4, {Pages }

    Abstract

    Background Early detection of outbreaks is very important for surveillance systems. Due to the importance of the subject and lack of similar studies in Iran, the aim of this study was to determine the performance of the Wavelet-Based Outbreak detection method) WOD (in detecting outbreaks and to compare its performance with Poisson regression-based model and Exponential weighted moving average (EWMA) using data of simulated pertussis outbreaks in Iran. Methods The data on suspected cases of pertussis from 25th February 2012 to 23rd March 2018 in Iran was used. The performance of the WOD (Daubechies 10 and Haar wavelets), Poisson regression-based method, and EWMA Compared in terms of timeliness and detection of outbreak days using the simulat

    Spatio-temporal analysis of Pertussis using geographic information system among Iranian population during 2012-2018

    Yousef Alimohamadi, Seyed Mohsen Zahraei, Manoochehr Karami, Mehdi Yaseri, Mojtaba Lotfizad, Kourosh Holakouie-Naieni
    Journal PaperMedical Journal of The Islamic Republic of Iran (MJIRI) , Volume 34 , Issue 1, 2020 February 10, {Pages 150-156 }

    Abstract

    Background: In spite of existing vaccination programs in many countries, outbreaks of pertussis are still reported. In Iran, the suspected and confirmed cases of pertussis are reported annually. Due to the lack of similar studies, the purpose of the current study was to determine the Spatio-temporal distribution of Pertussis using Geographic Information System (GIS) to identify high-risk areas in Iran during 2012-2018.Methods: In the current cross-sectional study, registered data in the department of vaccine-preventable diseases in the Iranian ministry of health were used. To assess the temporal trend, the Cochran–Armitage test was used. To show the spatial distribution and to identify hotspot areas, Choropleth map and Getis-Ord Gi statis

    Timely detection of Pertussis outbreaks in Iran: The comparison performance of Wavelet-based outbreak detector, Exponential weighted moving average, and Poisson regression?…

    Yousef Alimohamadi, Seyed Mohsen Zahraei, Manoochehr Karami, Mehdi Yaseri, Mojtaba Lotfizad, Kourosh Holakouie-Naieni
    Journal Paper , 2020 February 4, {Pages }

    Abstract

    Background Early detection of outbreaks is very important for surveillance systems. Due to the importance of the subject and lack of similar studies in Iran, the aim of this study was to determine the performance of the Wavelet-Based Outbreak detection method) WOD (in detecting outbreaks and to compare its performance with Poisson regression-based model and Exponential weighted moving average (EWMA) using data of simulated pertussis outbreaks in Iran.Methods The data on suspected cases of pertussis from 25th February 2012 to 23rd March 2018 in Iran was used. The performance of the WOD (Daubechies 10 and Haar wavelets), Poisson regression-based method, and EWMA Compared in terms of timeliness and detection of outbreak days using the simulati

    Alarm Thresholds for Pertussis Outbreaks in Iran: National Data Analysis

    Yousef Alimohamadi, Seyed Mohsen Zahraei, Manoochehr Karami, Mehdi Yaseri, Mojtaba Lotfizad, Kourosh Holakouie-Naieni
    Journal PaperOsong Public Health and Research Perspectives , Volume 11 , Issue 5, 2020 October , {Pages 309 }

    Abstract

    ObjectivesThe purpose of the current study was to determine the upper threshold number of cases for which pertussis infection would reach an outbreak level nationally in Iran.MethodsData on suspected cases of pertussis from the 25 th February 2012 to the 23 rd March 2018 from the Center for Disease Control and Prevention in Iran was used. The national upper threshold level was estimated using the exponentially weighted moving average (EWMA) method and the Poisson regression method.ResultsIn total, 2,577 (33.6%) and 1,714 (22.3%) cases were reported in the Spring and Summer respectively. There were 1,417 (18.5%) and 1,971 (25.6%) cases reported in the Autumn and Winter, respectively. The overall upper threshold using the EWMA and the Poisson

    The comparative performance of wavelet‐based outbreak detector, exponential weighted moving average, and Poisson regression‐based methods in detection of pertussis outbreaks in?…

    Yousef Alimohamadi, Seyed Mohsen Zahraei, Manoochehr Karami, Mehdi Yaseri, Mojtaba Lotfizad, Kourosh Holakouie‐Naieni
    Journal PaperPediatric Pulmonology , 2020 August 22, {Pages }

    Abstract

    Background Early detection of outbreaks of transmissible diseases is essential for public health. This study aimed to determine the performance of the wavelet‐based outbreak detection method (WOD) in detecting outbreaks and to compare its performance with the Poisson regression‐based model and exponentially weighted moving average (EWMA) using data of simulated pertussis outbreaks in Iran. Method The data on suspected cases of pertussis from 25th February 2012 to 23rd March 2018 in Iran was used. The performance of the WOD (Daubechies 10 [db10] and Haar wavelets), Poisson regression‐based method, and EWMA Compared in terms of timeliness and detection of outbreak days using the simulation of different outbreaks. In the current stud

    The comparative performance of wavelet‐based outbreak detector, exponential weighted moving average, and Poisson regression‐based methods in detection of pertussis outbreaks in …

    Y Alimohamadi, SM Zahraei, M Karami, M Yaseri, M Lotfizad, ...
    Journal Paper , , {Pages }

    Abstract

    Timely detection of Pertussis outbreaks in Iran: The comparison performance of Wavelet-based outbreak detector, Exponential weighted moving average, and Poisson regression …

    Y Alimohamadi, SM Zahraei, M Karami, M Yaseri, M Lotfizad, ...
    Journal Paper , , {Pages }

    Abstract

    Visual tracking via decision-based particle filtering based on sparse representation

    Mohamad Hosein Davoodabadi Farahani, Mojtaba Lotfizad
    Journal PaperJournal of Electronic Imaging , Volume 27 , Issue 4, 2018 July , {Pages 043027 }

    Abstract

    Many approaches for effective object tracking have been proposed in the literature, among which the sparse representation has been a successful method for finding the best candidate with the minimal reconstruction error. We propose a generic object tracking algorithm using the sparse representation of the target’s local patches. Sparse codes are adopted as a confidence measure to avoid drifting from the target during tracking. Experiments demonstrate that mentioned confidence measure can specify appearance change of the target accurately. Furthermore, given this measure, we propose a double search scheme for tracking targets. By using this approach, the proposed tracker can work with fewer particles than its rivals and as a result does no

    Improved clipped affine projection adaptive algorithm

    Mehdi Bekrani, Ruhollah Bibak, Mojtaba Lotfizad
    Journal PaperIET Signal Processing , Volume 13 , Issue 1, 2018 August 21, {Pages 103-111 }

    Abstract

    In this study, a modification to the affine projection adaptive filtering algorithm is proposed which is based on a three-level clipping of the input signal as applied to the weight update process. This clipping operation causes the input signal to be quantised into three levels, namely, 0, 1, and −1. By doing so, the proposed scheme, in addition to reducing the computational complexity, achieves an error convergence performance that is comparable to, or even at times better than that of the conventional affine projection algorithm (APA) for a certain range of the clipping threshold. The proposed adaptive algorithm is compared with some low complexity variants of APA with respect to the convergence rate and computational complexity, and i

    Design of an S-Band Ultra-Low-Noise Amplifier with Frequency Band Switching Capability

    Majid Shakibmehr, Mojtaba Lotfizad
    Journal PaperJournal of Electrical and Computer Engineering Innovations , Volume 5 , Issue 1, 2017 November 1, {Pages 13-18 }

    Abstract

    In this paper, an ultra-low-noise amplifier with frequency band switching capability is designed, simulated and fabricated. The two frequency ranges of this amplifier consist of the 2.4 to 2.5 GHz and 3.1 GHz to 3.15 GHz frequency bands. The designed amplifier has a noise figure of less than 1dB, a minimum gain of 23 dB and a VSWR of less than 2 in the whole frequency band. The design process starts with increasing the stability factor in the source through manipulating the inductor placement technique. Then the input and output matching circuits for the first frequency band are designed. This process is completed by utilizing two similar stages placed successively in order to achieve the desired gain level. Since no degradation of the nois

    Visual Tracking using Corner based Centrist Descriptor with a Robust Localization Algorithm

    Mahdi Tanbakuchi, Mojtaba Lotfizad
    Journal PaperInternational Journal of Computer Applications , Volume 153 , Issue 6, 2016 January , {Pages }

    Abstract

    In this paper an algorithm for object tracking in the visual domain based on a novel localization method is proposed. First a part of the search area, preferably the interest points is chosen. The proposed approach drastically speeds up the process of tracking, meanwhile the intensity histogram and Centrist descriptor which is known for good coding capability of small patches of an image will be used for target’s description. In order to increase the accuracy of the descriptor, this descriptor is applied to small blocks of image to encode most of the image around the target’s interest points. By providing the description of object’s interest points, a 1-NN classifier is used to distinguish the corresponding target’s interest points

    Design of a High-Frequency Very Low-Power Direct Digital Frequency Synthesizer

    Mojtaba Hasannezhad, Abumoslem Jannesari, Mojtaba Lotfizad
    Journal PaperJournal of Circuits, Systems and Computers , Volume 25 , Issue 08, 2016 August , {Pages 1650085 }

    Abstract

    This paper presented a low-power Direct Digital Frequency Synthesizer (DDFS) using non-uniform sine-weighted digital-to-analog convertor (DAC). To avoid the need for a sharp filter to generate signals near and beyond the Nyquist frequency, parallel DACs, which cause to speed relaxation in a single DAC as well, and return-to-zero (RZ) technique were used. To reduce the area and power in parallel DACs, non-uniform sine-weighted DAC design method was proposed. This technique causes to reduce power consumption in DACs up to 48.47%, and nearly the same amount of reduction in the area. Meanwhile, by modifying weights of DAC cells, Gilbert cell, the latter block in DDFS structure, was omitted. Although these proposed methods are quite frequency in

    Clipped LMS/RLS Adaptive Algorithms: Analytical Evaluation and Performance Comparison with Low-Complexity Counterparts

    Mehdi Bekrani, Mojtaba Lotfizad
    Journal PaperCircuits, Systems, and Signal Processing , Volume 34 , Issue 5, 2015 May 1, {Pages 1655-1682 }

    Abstract

    The high computational load of conventional adaptive FIR filters applied to long system identification and their weak tracking ability has encouraged researchers to seek for efficient adaptive algorithms for this kind of applications. One of the efficient solutions is the three-level clipped LMS/RLS adaptive algorithm. In this paper, an insight into the performance of these adaptive algorithms that evaluates the amount of steady-state misalignment error of clipped LMS/RLS adaptive algorithms employed for identification of time-invariant and time-varying systems, is presented. Employing it, we compare the misalignment performance with their low-complexity adaptive algorithm counterparts theoretically. In addition, we derive th

    Variable step size modified clipped LMS algorithm

    Amin Aref, Mojtaba Lotfizad
    Conference PaperKnowledge-Based Engineering and Innovation (KBEI), 2015 2nd International Conference on , 2015 November 5, {Pages 546-550 }

    Abstract

    In this paper we introduce an Modified Clipped LMS (MCLMS) algorithm with a variable step size. In the MCLMS algorithm two parameters, the step size and the threshold control the convergence rate of the adaptive filter coefficients and also determine the final mean-square error. The computational complexity decreased dramatically by a large threshold. However, this selection results in a low convergence rate. Since the convergence time is inversely proportional to the step size, a large step size is often selected for fast convergence. But a large step size results in an increased final mean square error. Therefore in this paper we choose a large threshold and propose a variable step size for the MCLMS algorithm. The advantages of this prop

    Achieving Better Performance of S-MMA Algorithm in the OFDM Modulation

    Saeed Ghazi-Maghrebi, Babak Haji Bagher Naeeni, Mojtaba Lotfizad
    Journal PaperJournal of Information Systems & Telecommunication , Volume 1 , Issue 1, 2013 January , {Pages 17-Sep }

    Abstract

    Effective algorithms in modern digital communication systems provide a fundamental basis for increasing the efficiency of the application networks which are in many cases neither optimized nor very close to their practical limits. Equalizations are one of the preferred methods for increasing the efficiency of application systems such as orthogonal frequency division multiplexing (OFDM). In this paper, we study the possibility of improving the OFDM modulation employing sliced multi-modulus algorithm (S-MMA) equalization. We compare applying the least mean square (LMS), multi modulus algorithm (MMA) and S-MMA equalizations to the per tone equalization in the OFDM modulation. The paper contribution lies in using the S-MMA technique, for weight

    Achieving Better Performance of S-MMA Algorithm in the OFDM Modulation

    S Ghazi-Maghrebi, BHB Naeeni, M Lotfizad
    Journal Paper , , {Pages }

    Abstract

    A target-based color space for sea target detection

    Saeed Mirghasemi, Hadi Sadoghi Yazdi, Mojtaba Lotfizad
    Journal PaperApplied Intelligence , Volume 36 , Issue 4, 2012 June 1, {Pages 960-978 }

    Abstract

    Sea target detection is a vital application for military and navigation purposes. A new supervised clustering method based on the combination of the PSO and FCM techniques is presented for the sea target detection problem. The color components of the target and non-target pixels in the RGB color space are used as features to train the classification algorithm. The new classifier is presented in the form of a new color space which we call the Target-based Color Space (TCS); in fact the RGB color space is converted to this new space through a 3?3 matrix. The Particle Swarm Optimization (PSO) algorithm is then used to search for the optimum weights of the conversion matrix which results in a more discriminating clustering space

    A new color space to discriminate skin regions using fuzzy quadratic programming

    Amir Mazaherie, Saeed Mirghasemi, Mojtaba Lotfizad
    Conference PaperInternational Conference on Graphic and Image Processing (ICGIP 2011) , Volume 8285 , 2011 October 1, {Pages 82853R }

    Abstract

    This paper presents a new color space through linear conversion in which the cost function has fuzzy quadratic (FQ) characteristic. Training samples are used to create an efficient color space with respect to desired application. Quadratic Programming (QP) technique is engaged to extract the conversion matrix. According to fuzzy feature of the cost function, several matrices are introduced to generate the new color space for skin segmentation. The proposed method involves two steps. First a second order cost function established based on separating target pixels from non-target ones while followed by some constraints. In the second stage, a quadratic optimization is used to solve problem efficiently. Finally, the results of fuzzy approach a

    A new mathematical analysis of the cyclic prefix effect on removing ISI and ICI in DMT systems

    Saeed Ghazi-Maghrebi, Hossein Motahayeri, Karen Der Avanesian, Mojtaba Lotfizad
    Conference PaperTENCON 2011-2011 IEEE Region 10 Conference , 2011 November 21, {Pages 237-241 }

    Abstract

    In this paper, a new mathematical analysis is presented that shows the effects of cyclic prefix insertion on removing inter symbol interference (ISI) and inter carrier interference (ICI) in the discrete multi-tone (DMT) systems. In the DMT, for subcarriers modulating, the input data stream is divided into lower rate sub-streams. The ISI is eliminated almost entirely by adding a guard interval (GI) at the beginning of each DMT symbol. However, rather than using an empty GI, this interval is filled with the end part of the DMT symbol. Through this method ISI and ICI are avoided. In all the previous works, the authors have shown the above results by only matrix analysis, without any information insight in different steps, but in this work we a

    Current Teaching

      Data not found

    Teaching History

      Data not found

    Top

    New

      no record found