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Total 23 records

    Coincidence based mapping extraction with genetic algorithms

    , Article 3rd International Conference on Web Information Systems and Technologies, Webist 2007, Barcelona, 3 March 2007 through 6 March 2007 ; Volume WIA , 2007 , Pages 176-183 Qazvinian, V ; Abolhassani, H ; Haeri, S. H ; Sharif University of Technology
    2007
    Abstract
    Ontology Aligning is an answer to the problem of handling heterogenous information on different domains. After application of some measures, one reaches a set of similarity values. The final goal is to extract mappings. Our contribution is to introduce a new genetic algorithm (GA) based extraction method. The GA, employs a structured based weighting model, named "coincidence based model", as its fitness function. In the first part of the paper, some preliminaries and notations are given and then we introduce the coincidence based weighting. In the second part the paper discusses the details of the devised GA with the evaluation results for a sample dataset  

    Treatment of oil-contaminated drill cuttings of South Pars gas field in Iran using supercritical carbon dioxide

    , Article Iranian Journal of Science and Technology, Transaction B: Engineering ; Volume 30, Issue 5 , 2006 , Pages 607-611 ; 03601307 (ISSN) Goodarznia, I ; Esmaeilzadeh, F ; Sharif University of Technology
    2006
    Abstract
    New treatment technologies are currently being investigated for the treatment of contaminated drilling waste mud with oil. Supercritical fluid extraction is a promising technology that could be effectively used to extract this contaminated drilling waste mud. In this work, one step extraction efficiency of supercritical carbon dioxide to drilling waste mud of South Pars gas field has been investigated at a range of temperatures (55 to 79.5 °C), and over a pressure range of 160 to 220 bar. Extraction efficiencies were calculated based on cuttings weight loss. Results show that approximately 28.45% of cuttings weight loss in one step extraction at a pressure of 200 bar and temperature of 60 °C... 

    Capacity and output power estimation approach of individual behind-the-meter distributed photovoltaic system for demand response baseline estimation

    , Article Applied Energy ; Volume 253 , 2019 ; 03062619 (ISSN) Li, K ; Wang, F ; Mi, Z ; Fotuhi Firuzabad, M ; Duić, N ; Wang, T ; Sharif University of Technology
    Elsevier Ltd  2019
    Abstract
    Accurate customer baseline load (CBL) estimation is critical for implementing incentive-based demand response (DR) programs. The increasing penetration of grid-tied distributed photovoltaic systems (DPVS) complicates customers’ load patterns, making the CBL estimation more difficult because the volatile actual load and the intermittent PV output power are coupled together. A PV-load decoupling framework is proposed in this paper to address the above issue. The basic idea is to decouple the actual load power and the PV output power, then estimate them separately. To this end, historical PV output power data of each individual DPVS is required. However, pure historical PV output power data is... 

    Separation of rhenium and molybdenum from molybdenite leach liquor by the solvent extraction method

    , Article Minerals and Metallurgical Processing ; Volume 30, Issue 1 , February , 2013 , Pages 53-58 ; 07479182 (ISSN) Khoshnevisan, A ; Yoozbashizadeh, H ; Mohammadi, M ; Abazarpoor, A ; Maarefvand, M ; Sharif University of Technology
    2013
    Abstract
    Molybdenum resources around the world are mainly associated with porphyry copper ores. Molybdenite (MoS2) is the main Mo mineral that has rhenium in its crystal lattice. This paper investigates the recovery of rhenium and molybdenum from a molybdenite concentrate using a hydrometallurgical treatment method. The molybdenite concentrate is leached with nitric acid and subjected to solvent extraction to recover and separate rhenium and molybdenum from the leached liquor. The effects of pH and the chemicals' concentration on extraction characteristics of Mo and Re are investigated to define the best condition for selective extraction of these metals. The tested leached liquor contained of 8.2... 

    Feature extraction using gabor-filter and recursive fisher linear discriminant with application in fingerprint identification

    , Article Proceedings of the 7th International Conference on Advances in Pattern Recognition, ICAPR 2009, 4 February 2009 through 6 February 2009, Kolkata ; 2009 , Pages 217-220 ; 9780769535203 (ISBN) Dadgostar, M ; Roshani Tabrizi, P ; Fatemizadeh, E ; Soltanian Zadeh, H ; Sharif University of Technology
    2009
    Abstract
    Fingerprint is widely used in identification and verification systems. In this paper, we present a novel feature extraction method based on Gabor filter and Recursive Fisher Linear Discriminate (RFLD) algorithm, which is used for fingerprint identification. Our proposed method is assessed on images from the biolab database. Experimental results show that applying RFLD to a Gabor filter in four orientations, in comparison with Gabor filter and PCA transform, increases the identification accuracy from 85.2% to 95.2% by nearest cluster center point classifier with Leave-One-Out method. Also, it has shown that applying RFLD to a Gabor filter in four orientations, in comparison with Gabor filter... 

    Extraction of molybdenum (VI) and vanadium (V) from nitrate solutions using coupling of acid and solvating extractants

    , Article International Journal of Engineering, Transactions A: Basics ; Volume 32, Issue 10 , 2019 , Pages 1366-1371 ; 17281431 (ISSN) Shakib, B ; Torab Mostaedi, M ; Outokesh, M ; Asadollahzadeh, M ; Sharif University of Technology
    Materials and Energy Research Center  2019
    Abstract
    In this study, solvent extraction method has been utilized for separation of molybdenum and vanadium from nitrate solution by utilizing coupling of acid and solvating extractants (D2EHPA and TBP extractants). The outcomes demonstrated that synergistic solvent extraction improves stability of formatted complexes for transfer to the organic phase. The main parameters such as pH value, concentration of extractants, NH4OH concentration as the stripping agent and contact time were optimized at 0.4, 15% (v/v) D2EHPA, 10% (v/v) TBP, 2 M and 30 min, respectively. The maximum separation factor of 24.84 was obtained with a new synergistic mixture of D2EHPA and TBP diluted with kerosene. According to... 

    A Novel Structural Based Similarity Measure for MRI and Ultrasound Registration

    , M.Sc. Thesis Sharif University of Technology Moaven, Aria (Author) ; Fatemizadeh, Emadodin (Supervisor)
    Abstract
    One of the most important issues in medical image processing is the registration of images with various imaging modalities, because in this case, one can take advantage of these imaging modalities and sometimes fuse and use the useful information of each one in the form of a single image.As it was said, MRI and ultrasound images each have their own disadvantages and advantages, and by considering these two modalities, they have tried to integrate the good features of these two. As we know, one of the destructive cases in the MRI image is the inhomogeneity of the image, a inhomogeneity due to the fact that the main magnetic field is not constant and makes the parts of the image brighter or... 

    On the parameter extraction of a five-parameter double-diode model of photovoltaic cells and modules

    , Article IEEE Journal of Photovoltaics ; Vol. 4, issue. 3 , 2014 , pp. 915-923 ; ISSN: 21563381 Hejri, M ; Mokhtari, H ; Azizian, M. R ; Ghandhari, M ; Soder, L ; Sharif University of Technology
    Abstract
    The main contribution of this paper is to present a new set of approximate analytical solutions for the parameters of a photovoltaic (PV) five-parameter double-diode model that can be used as initial values for the numerical solutions based on the Newton-Raphson method. The proposed formulations are developed based on only the limited information given by the PV manufacturers, i.e., the open-circuit voltage (V), the short circuit current (I), and the current and voltage at the maximum power point (Im). Compared with the existing techniques that require the entire experimental I-V curve or additional information such as the slope of the I-V curves of the open circuit and the short circuit... 

    Fuzzy local binary patterns: A comparison between Min-Max and Dot-Sum operators in the application of facial expression recognition

    , Article Iranian Conference on Machine Vision and Image Processing, MVIP, Zanjan ; 2013 , Pages 315-319 ; 21666776 (ISSN) ; 9781467361842 (ISBN) Mohammadi, M. R ; Fatemizadeh, E ; Sharif University of Technology
    Abstract
    The Local Binary Patterns (LBP) feature extraction method is a theoretically and computationally simple and efficient methodology for texture analysis. The LBP operator is used in many applications such as facial expression recognition and face recognition. The original LBP is based on hard thresholding the neighborhood of each pixel, which makes texture representation sensitive to noise. In addition, LBP cannot distinguish between a strong and a weak pattern. In order to enhance the LBP approach, Fuzzy Local Binary Patterns (FLBP) is proposed. In FLBP, any neighborhood does not represented only by one code, but, it is represented by all existing codes with different degrees. In FLBP, any... 

    An efficient diagnosis method for data mining on single PD pulses of transformer insulation defect models

    , Article IEEE Transactions on Dielectrics and Electrical Insulation ; Volume 20, Issue 6 , 2013 , Pages 2061-2072 ; 10709878 (ISSN) Darabad, V. P ; Vakilian, M ; Phung, B. T ; Blackburn, T. R ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2013
    Abstract
    Reviewing the various Partial Discharges (PD data mining researches which have been reported so far, this study compares the performance of different feature spaces and different classifiers employed for PD classification in insulation condition monitoring of power transformers. In this process, first a knowledge basis is developed through construction of 4 different types of PD models in the high voltage laboratory. Background noise is considered as one class in this knowledge basis. The high frequency time domain current signals of high voltage equipment are captured over one power frequency cycle. The single PD activities within this captured signal are extracted by application of a... 

    Large-scale image annotation using prototype-based models

    , Article ISPA 2011 - 7th International Symposium on Image and Signal Processing and Analysis ; 2011 , Pages 449-454 ; 9789531841597 (ISBN) Amiri, S. H ; Jamzad, M ; European Association for Signal Processing (EURASIP); IEEE Signal Processing Society; IEEE Region 8; IEEE Croatia Section; IEEE Croatia Section Signal Processing Chapter ; Sharif University of Technology
    Abstract
    Automatic image annotation is a challenging problem in the field of image retrieval. Dealing with large databases makes the annotation problem more difficult and therefore an effective approach is needed to manage such databases. In this work, an annotation system has been developed which considers images in separate categories and constructs a profiling model for each category. To describe an image, we propose a new feature extraction method based on color and texture information that describes image content using discrete distribution signatures. Image signatures of one category are partitioned using spectral clustering and a prototype is determined for each cluster by solving an... 

    Experimental study and thermodynamic modeling for determining the effect of non-polar solvent (hexane)/polar solvent (methanol) ratio and moisture content on the lipid extraction efficiency from Chlorella vulgaris

    , Article Bioresource Technology ; Volume 201 , 2016 , Pages 304-311 ; 09608524 (ISSN) Malekzadeh, M ; Abedini Najafabadi, H ; Hakim, M ; Feilizadeh, M ; Vossoughi, M ; Rashtchian, D ; Sharif University of Technology
    Elsevier Ltd 
    Abstract
    In this research, organic solvent composed of hexane and methanol was used for lipid extraction from dry and wet biomass of Chlorella vulgaris. The results indicated that lipid and fatty acid extraction yield was decreased by increasing the moisture content of biomass. However, the maximum extraction efficiency was attained by applying equivolume mixture of hexane and methanol for both dry and wet biomass. Thermodynamic modeling was employed to estimate the effect of hexane/methanol ratio and moisture content on fatty acid extraction yield. Hansen solubility parameter was used in adjusting the interaction parameters of the model, which led to decrease the number of tuning parameters from 6... 

    Comparison of ECG fiducial point extraction methods based on dynamic bayesian network

    , Article 2017 25th Iranian Conference on Electrical Engineering, ICEE 2017, 2 May 2017 through 4 May 2017 ; 2017 , Pages 95-100 ; 9781509059638 (ISBN) Akhbari, M ; Shamsollahi, M. B ; Jutten, C ; Sharif University of Technology
    Abstract
    Cardiovascular diseases are one of the major causes of mortality in humans. One way to diagnose heart diseases and abnormalities is processing of cardiac signals such as electrocardiogram (ECG) signal. In many ECG analysis, location of peak, onset and offset of ECG waves must be extracted as a preprocessing step. These points are called ECG fiducial points (FPs) and convey clinically useful information. In this paper, we compare some FP extraction methods including three methods proposed recently by our research team. These methods are based on extended Kalman filter (EKF), hidden Markov model (HMM) and switching Kalman filter (SKF). Results are given for ECG signals of QT database. For all... 

    Extended common spatial and temporal pattern (ECSTP): A semi-blind approach to extract features in ERP detection

    , Article Pattern Recognition ; Volume 95 , 2019 , Pages 128-135 ; 00313203 (ISSN) Jalilpour Monesi, M ; Hajipour Sardouie, S ; Sharif University of Technology
    Elsevier Ltd  2019
    Abstract
    Common spatial pattern (CSP) analysis and its extensions have been widely used as feature extraction approaches in the brain-computer interfaces (BCIs). However, most of the CSP-based approaches do not use any prior knowledge that might be available about the two conditions (classes) to be classified. Therefore, their applications are limited to datasets that contain enough variance information about the two conditions. For example, in some event-related potential (ERP) detection applications, such as P300 speller, the information is in the time domain but not in the variance of spatial components. To address this problem, first, we present a novel feature extraction method termed extended... 

    Double layer mesoscopic electron contact for efficient perovskite solar cells

    , Article Sustainable Energy and Fuels ; Volume 4, Issue 2 , 2020 , Pages 843-851 Chavan, R. D ; Yadav, P ; Tavakoli, M. M ; Prochowicz, D ; Nimbalkar, A ; Bhoite, S. P ; Bhosale, P. N ; Hong, C. K ; Sharif University of Technology
    Royal Society of Chemistry  2020
    Abstract
    Interface engineering has emerged as a great strategy for fabrication of high efficiency and stable perovskite solar cells (PSCs). Here, we deposit a thin layer of ZnS as a buffer layer at the interface of the perovskite absorber and electron transporting layer (ETL) using the atomic layer deposition (ALD) process. The impact of the ZnS layer on the photovoltaic characteristics of PSCs was investigated by comparison of two mesoscopic configurations, in which the ZnS layer is grown on compact TiO2 and on mesoporous TiO2 surfaces. Our results revealed that the addition of an ultrathin ZnS layer between the perovskite and ETL drastically improves the charge extraction properties and reduces... 

    Efficient carrier utilization induced by conductive polypyrrole additives in organic-inorganic halide perovskite solar cells

    , Article Solar Energy ; Volume 207 , 2020 , Pages 1300-1307 Zarenezhad, H ; Balkan, T ; Solati, N ; Halali, M ; Askari, M ; Kaya, S ; Sharif University of Technology
    Elsevier Ltd  2020
    Abstract
    The morphology of the perovskite layer, the effective extraction of the charge carriers, and their transport are the main factors determining the power conversion efficiency (PCE) of the perovskite solar cells (PSCs). In this work, we demonstrated that the geometric and electronic structures of the PSCs could be modified by using a conductive polymer additive in the lead (Pb) halide layer prepared by a two-step deposition method. Polypyrrole (PPy) as a conductive polymer is used in the perovskite layers which could increase the PCE of CH3NH3PbI3-xClx mixed-halide PSCs. By adding an optimized amount of PPy, PCE has been raised from 10.4 to 13.2%. PPy acts as a conductive channel facilitating... 

    Study and optimization of amino acid extraction by emulsion liquid membrane

    , Article Separation Science and Technology ; Volume 43, Issue 11-12 , 2008 , Pages 3075-3096 ; 01496395 (ISSN) Mohagheghi, E ; Alemzadeh, I ; Vossoughi, M ; Sharif University of Technology
    2008
    Abstract
    A batch extraction of an essential amino acid, phenylalanine, from an aqueous solution of different concentrations by an Emulsion Liquid Membrane (ELM) was developed using D2EHPA as a cationic carrier, Span 80 as the surfactant, paraffin, and kerosene as the diluents, and HCl as the internal electrolyte. All effective parameters such as the initial pH of the aqueous external phase, the electrolyte concentration in the aqueous internal phase, carrier, and surfactant concentration in the emulsion, the volume ratio of the organic to aqueous internal phase (Roi), the volume ratio of the W/O emulsion to the aqueous external phase (Rew) and time were examined and optimized using the Taguchi... 

    RCTP: Regularized common tensor pattern for rapid serial visual presentation spellers

    , Article Biomedical Signal Processing and Control ; Volume 70 , September , 2021 ; 17468094 (ISSN) Jalilpour, S ; Hajipour Sardouie, S ; Sharif University of Technology
    Elsevier Ltd  2021
    Abstract
    Common Spatial Pattern (CSP) is a powerful feature extraction method in brain-computer interface (BCI) systems. However, the CSP method has some deficiencies that limit its beneficiary. First, this method is not useful when data is noisy, and it is necessary to have a large dataset because CSP is inclined to overfit. Second, the CSP method uses just the spatial information of the data, and it cannot incorporate the temporal and spectral information. In this paper, we propose a new CSP-based algorithm which is capable of employing the information in all dimensions of data. Also, by defining the regularization term for each mode of information, we can diminish the noise effects and overfitting... 

    Improving dye removal and antifouling performance of polysulfone nanofiltration membranes by incorporation of UiO-66 metal-organic framework

    , Article Journal of Environmental Chemical Engineering ; Volume 10, Issue 3 , 2022 ; 22133437 (ISSN) Ahmadipouya, S ; Mousavi, S. A ; Shokrgozar, A ; Mousavi, D. V ; Sharif University of Technology
    Elsevier Ltd  2022
    Abstract
    In the present work, a series of polysulfone (PSf) mixed-matrix nanofiltration membranes containing highly water stable UiO-66 metal-organic framework (MOF) were prepared via a simple phase inversion technique. At first, UiO-66 particles were synthesized via a solvothermal technique, activated via two various activation methods, including Soxhlet extraction and centrifugation methods. Then their adsorption performance was investigated for adsorption of anionic methyl orange (MO)/methyl red (MR) and cationic methylene blue (MB)/malachite green (MG) dyes from water. The activated UiO-66 particles via the Soxhlet extraction method (named S-UiO-66) showed better performance for dye adsorption... 

    Superheated water extraction of catechins from green tea leaves: Modeling and simulation

    , Article Scientia Iranica ; Volume 16, Issue 2 C , 2009 , Pages 99-107 ; 10263098 (ISSN) Goodarznia, I ; Abdollahi Govar, A ; Sharif University of Technology
    2009
    Abstract
    Catechins from fresh green tea leaves as potential sources of anticancer and antioxidant components were target materials in this work. Superheated water extraction, which is a kind of leaching operation, and solvent partition with chloroform and ethyl acetate were utilized to recover Catechins from tea leaves. Then, a mathematical model was developed to simulate the superheated water extraction of Catechins. The unsteady state mass balance of the solute in solid and superheated water phases led to two partial differential equations. The model was solved numerically using a linear equilibrium relationship. The model parameters were predicted applying existing experimental correlations. An...