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Search Results: 1 - 10 of 1378 matches for " Mahdi Eftekhari "
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Automatic Model-Based Software Performance Optimization Based on MOPSO
Maryam Amoozegar,Mahdi Eftekhari
Intelligent Systems in Electrical Engineering , 2011,
Abstract: Software performance engineering in early life cycle of software development (software modeling) is very useful and cost effective, but not fully automated yet. This paper presents an optimization method based on multi-objective particle swarm optimization (MOPSO) for exploring the software design space automatically and proposes the best configuration in terms of performance evaluation. The software model is transformed in to a performance model, which is based on Layered Queueing Networks (LQNs). Then, the model will be optimized and feedback to the software model. One case study is utilized for evaluating the proposed method. The results obtained apparently show the optimization performance of MOPSO.
Comparison of different T-norm operators in classification problems
Fahimeh Farahbod,Mahdi Eftekhari
Computer Science , 2012, DOI: 10.5121/ijfls.2012.2303
Abstract: Fuzzy rule based classification systems are one of the most popular fuzzy modeling systems used in pattern classification problems. This paper investigates the effect of applying nine different T-norms in fuzzy rule based classification systems. In the recent researches, fuzzy versions of confidence and support merits from the field of data mining have been widely used for both rules selecting and weighting in the construction of fuzzy rule based classification systems. For calculating these merits the product has been usually used as a T-norm. In this paper different T-norms have been used for calculating the confidence and support measures. Therefore, the calculations in rule selection and rule weighting steps (in the process of constructing the fuzzy rule based classification systems) are modified by employing these T-norms. Consequently, these changes in calculation results in altering the overall accuracy of rule based classification systems. Experimental results obtained on some well-known data sets show that the best performance is produced by employing the Aczel-Alsina operator in terms of the classification accuracy, the second best operator is Dubois-Prade and the third best operator is Dombi. In experiments, we have used 12 data sets with numerical attributes from the University of California, Irvine machine learning repository (UCI).
A New Method to Measure the Similarity between Features in Machine Learning Using the Triangular Fuzzy Number
Hassan Nosrati Nahook,Mahdi Eftekhari
International Journal of Soft Computing & Engineering , 2013,
Abstract: In this paper, we present a new method to measure the similarity between features using fuzzy numbers. The proposed method uses the concept of geometry to calculate the degree of similarity between triangular fuzzy numbers defined on the features. We also prove some properties of the proposed similarity measure and use different data sets to compare the proposed method with existing methods. In the feature selection methods, the proposed similarity measure compared with other fuzzy similarity measures can be more efficient.
Using Na ve Bayes Classifier to Accelerate Constructing Fuzzy Intrusion Detection Systems
Mehran Amiri,Mahdi Eftekhari,Farshid Keynia
International Journal of Soft Computing & Engineering , 2013,
Abstract: A Bayesian classifier is one of the most widely used classifiers which possess several properties that make it surprisingly useful and accurate. It is illustrated that performance of Bayesian learning in some cases is comparable with neural networks and decision trees. Bayesian theorem suggests a straight forward process which is not based on search methods. This is the major point which satisfies the marvelous time complexity of Bayesian classifier. At the other hand, constructing phase of fuzzy intrusion detection systems suffer from time consuming processes which are based on search methods. In this paper we propose a novel method to accelerate such processes using Bayesian inference. Experimental results show meaningful time reduction.
A Study on Rational Function Model Generation for TerraSAR-X Imagery
Akram Eftekhari,Mohammad Saadatseresht,Mahdi Motagh
Sensors , 2013, DOI: 10.3390/s130912030
Abstract: The Rational Function Model (RFM) has been widely used as an alternative to rigorous sensor models of high-resolution optical imagery in photogrammetry and remote sensing geometric processing. However, not much work has been done to evaluate the applicability of the RF model for Synthetic Aperture Radar (SAR) image processing. This paper investigates how to generate a Rational Polynomial Coefficient (RPC) for high-resolution TerraSAR-X imagery using an independent approach. The experimental results demonstrate that the RFM obtained using the independent approach fits the Range-Doppler physical sensor model with an accuracy of greater than 10 ?3 pixel. Because independent RPCs indicate absolute errors in geolocation, two methods can be used to improve the geometric accuracy of the RFM. In the first method, Ground Control Points (GCPs) are used to update SAR sensor orientation parameters, and the RPCs are calculated using the updated parameters. Our experiment demonstrates that by using three control points in the corners of the image, an accuracy of 0.69 pixels in range and 0.88 pixels in the azimuth direction is achieved. For the second method, we tested the use of an affine model for refining RPCs. In this case, by applying four GCPs in the corners of the image, the accuracy reached 0.75 pixels in range and 0.82 pixels in the azimuth direction.
Bone Scan with Incidental Visualization of the Entire Colon
Mohammad Eftekhari,Armaghan Fard-Esfahani,Mahdi Haghighatafshar,Arash Keivan
Iranian Journal of Nuclear Medicine , 2010,
Abstract: A 57-year-old male with history of prostatectomy, cyctectomy, cecal urinary diversion for invasive prostate cancer and with a recent rise in PSA level, was referred for bone scintigraphy to rule out osseous metastatic disease. An interesting finding was abnormal tracer accumulation throughout the large bowel, which was proved to be due to urinary diversion.
Detection of Mycobacterium paratuberculosis in Feces and Milk Samples from Holstein Dairy Cows by PCR
Mahdi Soltani,Mohammad Reza Nassiry,Freidoun Eftekhari Shahroudi,Mohammad Reza Bassami
Biotechnology , 2008,
Abstract: Mycobacterium paratuberculosis, an acid-fast bacterium is the agent of Johne`s disease, an intestinal disease that cause poor nutrient intake in ruminants. Because of the heavy economic loses due to this disease, a diagnostic procedure must be defined that could determine the disease in its initial stages. PCR method based on specific IS900 locus primers was used. Feces and milk samples were collected from 68 Holstein dairy cows. 19 feces samples (of 68 samples) were PCR positive whereas 10 milk samples (of 56 samples) were positive. Results of this study showed that PCR might be the preferred method for detection of the disease with feces and milk samples because of its simplicity, sensitivity and rapidity.
Preana: Game Theory Based Prediction with Reinforcement Learning  [PDF]
Zahra Eftekhari, Shahram Rahimi
Natural Science (NS) , 2014, DOI: 10.4236/ns.2014.613099

In this article, we have developed a game theory based prediction tool, named Preana, based on a promising model developed by Professor Bruce Beuno de Mesquita. The first part of this work is dedicated to exploration of the specifics of Mesquita’s algorithm and reproduction of the factors and features that have not been revealed in literature. In addition, we have developed a learning mechanism to model the players’ reasoning ability when it comes to taking risks. Preana can predict the outcome of any issue with multiple steak-holders who have conflicting interests in economic, business, and political sciences. We have utilized game theory, expected utility theory, Median voter theory, probability distribution and reinforcement learning. We were able to reproduce Mesquita’s reported results and have included two case studies from his publications and compared his results to that of Preana. We have also applied Preana on Irans 2013 presidential election to verify the accuracy of the prediction made by Preana.

Towards Economic Single-Phase Motor  [PDF]
Mahdi Alshamasin
Energy and Power Engineering (EPE) , 2013, DOI: 10.4236/epe.2013.59058

Studying of operation balance in single-phase induction motors is an issue of interest due to the need for reducing the power consumption and increasing the motors’ life. The paper focuses on improving the motor performance by balancing the stator phase operation for the most common-used connection diagrams of single-phase capacitor-run induction motors (SPCRIMs) and three-phase induction motors (TPIMs) operating from single-phase supply (SPS). Therefore, a mathematical model is used to balance the motor operation by varying the frequency supply voltage. Characteristics of balancing parameters are investigated, various methods of motor balancing are presented and comparisons were done among these balancing methods.

Upper Airway Obstruction in the Infants and Children
F. Eftekhari
Iranian Journal of Radiology , 2008,
Abstract: Acute upper airway obstruction in the newborn and infants is considered one of many emergencies in the practice of pediatric radiology, and not uncommonly in general radiology. The reasons are relatively smaller caliber of the air way, ensuing inflammation which will quickly result in hypoxia, pulmonary edema and death. Physical examination and laryngoscopy may prove quite risky, causing additional spasm and sudden death. The imaging examinations such as conventional radiography of the neck, ultrasound or MR are much safer and will enable the radiologist arrive at reasonably accurate diagnosis and expedite medical or surgical treatment."nDuring this session we will address many causes of upper air way obstruction, the mechanism of obstruction and briefly review the treatment options."nCongenital anomalies that may interfere with integrity of the upper airways include various cysts, teratomas, goiter, hemangioma, lymphangioma (cystic hygroma), tracheal webs and compression by anomalous vessels."nInfectious causes include subglottic edema, supraglottitis (epiglottitis) and retropharyngeal ab-scess.Acquired lesions include post tracheostomy scars, tracheomalacia, foreign body aspiration and ingestion.After attending this session, the participants should be able to apply the key points in their daily practice and prevent catastrophic events.
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