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    Estimation of Power Peaking Factor (PPF)Parameter in VVER Reactor Using Soft Computing, Case Study: Bushehr Nuclear Power Plant

    , M.Sc. Thesis Sharif University of Technology Sharifi, Saeed (Author) ; Ghofrani, Mohammad Bagher (Supervisor) ; Moshkbar Bakhshayesh, Khalil (Supervisor)
    operation of a nuclear power plant. Therefore, constant monitoring of the reactor core with reliable methods is important. To monitor the reactor heart, it is necessary to estimate and calculate some parameters, with high speed and accuracy, such as power distribution inside the heart, reactivity feedback coefficients, PPF, DNBR, etc. Analytical methods are often used to calculate these parameters, which in case of failure of the sensors, the calculations will be practically disrupted, and the method used in this research can solve these problems by losing a small amount of accuracy.In this study using real data of Bushehr nuclear power plant (BNPP) and by soft computing methods and... 

    Forecasting the Possibility of Agricultural Drought using Markov Chain Based on Satellite data and Standard Precipitation Index

    , M.Sc. Thesis Sharif University of Technology Kolahdouzan, Mohammad Ehsan (Author) ; Abrishamchi, Ahmad (Supervisor)
    In comparison with flood, drought is a phenomenon that happens gradually and causes significant changes in water resources, environmental and economic damages specially farming. Due to random features of involving factors in occurrence and intensity of drought, it is assumed as a random process. Drought forecast has an important role in water resources management and control. Data validation, in drought forecast, is a matter of utmost importance. In recent years, satellite data is a type of data that has been used. Markov chain has been used here because one of the features of this method is that occurrence of each variable in current stage is dependent on its previous stage. On the other... 

    Comparison of River Daily Runoff Simulation Results using Time Series and IHACRES Rainfall-runoff Model

    , M.Sc. Thesis Sharif University of Technology Rahsepar Tolouei, Talaye (Author) ; Shamsaei, Abolfazl (Supervisor)
    Hydrologic models are the best tools to reduce hydrological uncertainties in rivers runoff estimation. Considering structure of model and calibration of parameters, there are several approaches to extend. In this study, we try to simulate daily river runoff by using two different approaches and then compare the results of them with each other. In first approach, IHACRES model is used to simulate rainfall- runoff, which is a conceptual model based on rainfall, runoff and evapotranspiration or temperature data. This model uses conceptual part to estimate effective rainfall and also it uses a transformation function to transform effective rainfall to output flow. This model works in daily time... 

    Short Time Effect of Auxetic Shoe on Kinematics and Kinetics of Vertebral Column During Drop Vertical Jump

    , M.Sc. Thesis Sharif University of Technology Rahmani Dahaghani, Mostafa (Author) ; Nourani, Amir (Supervisor) ; Arjmand, Navid (Supervisor)
    Investigating the influence of shoes on variables of human biomechanics is of a high importance. The purpose of this study was to examine the effect of auxetic Nike Free RN shoe on kinematics and kinetics of human body. It was asked from 11 healthy male to perform drop vertical jump in three conditions: with auxetic Nike Free RN, with conventional shoe and barefoot. 3D Cartesian positions of the markers, which were stuck to the subjects’ bodies, were recoeded using Vicon camera system. Ground reaction force and its center of pressure of each foot captured using two force plates. Moreover, activation of rectus abdominis, longissimus, iliocostalis lomburom and multifidus were recorded using... 

    Prediction of Lumbar Muscle Forces Due to Applied Externally Moment and Analaysing Coactivation Between Lumbar Muscles

    , M.Sc. Thesis Sharif University of Technology Khodadad Kani, Hadi (Author) ; Parnianpour, Mohammad (Supervisor) ; Shams Al-Allahi, Mohammad Bagher (Co-Advisor)
    The role of the lumbar muscles in maintaining posture and balancing externally applied loads has been studied for many years.preliminary studies used electromyograpy (EMG) to establish a relationship between trunk posture and muscle ativity.so developing a better undrestanding of the functional role of those muscles. Determination of lumbar muscle forces, will have an important role in reducing low back pain I future.For this reason,reaserchers have done many studies for understanding the resistence and function on the musulosketal system bye using of various protocls and have utilized of various biomechanical models for determining the effects of applied externally loads on lumbar... 

    The estimation of formation permeability in a carbonate reservoir using an artificial neural network

    , Article Petroleum Science and Technology ; Vol. 30, issue. 10 , Apr , 2010 , p. 1021-1030 ; ISSN: 10916466 Yeganeh, M ; Masihi, M ; Fatholah,i S ; Sharif University of Technology
    Reservoir permeability is an important parameter that its reliable prediction is necessary for reservoir performance assessment and management. Although many empirical formulas are derived regarding permeability and porosity in sandstone reservoirs, these correlations cannot be accurately depicted in carbonate reservoir for the wells that are not cored and for which there are no welltest data. Therefore, having a framework for estimation of these parameters in reservoirs with neither coring samples nor welltest data is crucial. Rock properties are characterized by using different well logs. However, there is no specific petrophysical log for estimating rock permeability; thus, new methods... 

    An electrospun magnetic nanocomposite for a facile micro-scaled analysis approach

    , Article Analytical Methods ; Vol. 6, issue. 15 , 2014 , Pages 5838-5846 ; ISSN: 17599660 Bagheri, H ; Roostaie, A ; Daliri, R ; Sharif University of Technology
    A magnetic polyurethane (PU) nanocomposite was synthesized by an electrospinning technique and applied for isolation and preconcentration of fluoxetine from aquatic and biological samples. The nanocomposite was electrospun using a PU polymer solution containing the dispersed magnetic nanoparticles. The magnetic properties of iron nanoparticles, along with the use of an electrospinning technique, led to the formation of a suitable sorbent toward isolation of fluoxetine. The magnetic PU nanofibers could be subsequently removed from the sample solution by applying a permanent magnet. The scanning electron microscopy (SEM) image of the magnetic PU nanofibers confirms that their diameters are in... 

    Voltammetric monitoring of Cd (II) by nano-TiO2 modified carbon paste electrode sensitized using 1,2-bis-[o-aminophenyl thio] ethane as a new ion receptor

    , Article Sensors and Actuators, B: Chemical ; Vol. 192 , 2014 , pp. 648-657 ; ISSN: 09254005 Ramezani, S ; Ghobadi, M ; Bideh, B. N ; Sharif University of Technology
    The objective of the work ahead is presentation of a new carbon paste electrode (CPE) modified by TiO2 nanoparticles (TiO2NPs) and 1,2-bis-[o-aminophenyl thio] ethane (APTE) ligand as a selective cation receptor for determination of the Cd (II) ions using differential pulse anodic stripping voltammetry (DPASV). The electrode shows an excellent tendency to Cd (II) ions in presence of some interfering species. Under the optimum conditions, a linear calibration curve was obtained in the concentration range of 2.9 nM to 4.6 μM with a correlation coefficient of 0.9969 in the anodic potential of 0.54 (V vs. Ag/AgCl). The metal detection limit was 2.0 nM after 10 min preconcentration (S/N = 3). The... 

    State-of-the-art least square support vector machine application for accurate determination of natural gas viscosity

    , Article Industrial and Engineering Chemistry Research ; Vol. 53, issue. 2 , 2014 , pp. 945-958 ; ISSN: 08885885 Fayazi, A ; Arabloo, M ; Shokrollahi, A ; Zargari, M. H ; Ghazanfari, M. H ; Sharif University of Technology
    Estimation of the viscosity of naturally occurring petroleum gases is essential to provide more accurate analysis of gas reservoir engineering problems. In this study, a new soft computing approach, namely, least square support vector machine (LSSVM) modeling, optimized with a coupled simulated annealing technique was applied for estimation of the natural gas viscosities at different temperature and pressure conditions. This model was developed based on 2485 viscosity data sets of 22 gas mixtures. The model predictions showed an average absolute relative error of 0.26% and a correlation coefficient of 0.99. The results of the proposed model were also compared with the well-known predictive... 

    Sparse-induced similarity measure: Mono-modal image registration via sparse-induced similarity measure

    , Article IET Image Processing ; Volume 8, Issue 12 , 1 December , 2014 , Pages 728-741 ; ISSN: 17519659 Ghaffari, A ; Fatemizadeh, E ; Sharif University of Technology
    Similarity measure is an important key in image registration. Most traditional intensity-based similarity measures (e.g. sum-of-squared-differences, correlation coefficient, mutual information and correlation ratio) assume a stationary image and pixel-by-pixel independence. These similarity measures ignore the correlation among pixel intensities; hence, a perfect image registration cannot be achieved especially in the presence of spatially varying intensity distortions and outlier objects that appear in one image but not in the other. It is supposed here that non-stationary intensity distortion (such as bias field) has a sparse representation in the transformation domain. Based on this... 

    Prediction of natural gas flow through chokes using support vector machine algorithm

    , Article Journal of Natural Gas Science and Engineering ; Vol. 18, issue , 2014 , pp. 155-163 ; ISSN: 18755100 Nejatian, I ; Kanani, M ; Arabloo, M ; Bahadori, A ; Zendehboudi, S ; Sharif University of Technology
    In oil and gas fields, it is a common practice to flow liquid and gas mixtures through choke valves. In general, different types of primary valves are employed to control pressure and flow rate when the producing well directs the natural gas to the processing equipment. In this case, the valve normally is affected by elevated levels of flow (or velocity) as well as solid materials suspended in the gas phase (e.g., fine sand and other debris). Both surface and subsurface chokes may be installed to regulate flow rates and to protect the porous medium and surface facilities from unusual pressure instabilities.In this study a reliable, novel, computer based predictive model using Least-Squares... 

    Assessment of competitive dye removal using a reliable method

    , Article Journal of Environmental Chemical Engineering ; Vol. 2, issue. 3 , September , 2014 , p. 1672-1683 Abdi, J ; Bastani, D ; Abdi, J ; Mahmoodi, N. M ; Shokrollahi, A ; Mohammadi, A. H ; Sharif University of Technology
    In this study, a reliable and predictive model namely, least-squares support vector machine (LS-SVM) was developed to predict dye removal efficiency. Four LS-SVM models have been developed and tested using more than 630 series of experimental data which were obtained from our previous paper. These data consist of adsorbate type, adsorbent dosage, initial dye concentration, salt, absorbance time and dye removal efficiency. Direct Red 31 (DR31), Direct Green 6 (DG6) and Acid Blue (AB92) were used as a model dyes. The results show that the developed model is more accurate and reliable with the average absolute relative deviation of 0.678%, 0.877%, 0.581% and 0.978% for single systems and... 

    Simple and efficient method to measure vessel tortuosity

    , Article Proceedings of the 3rd International Conference on Computer and Knowledge Engineering, ICCKE 2013, Mashhad: Iran ; 2013 , Pages 219-222 ; 9781479920921 (ISBN) Pourreza, H. R ; Pourreza, M ; Banaee, T ; Sharif University of Technology
    Retinal vessels tortuosity is one of the important signs of cardiovascular diseases such as diabetic retinopathy and hypertension. In this paper we present a simple and efficient algorithm to measure the grade of tortuosity in retinal images. This algorithm consists of four main steps,vessel detection, extracting vascular skeleton via thinning, detection of vessel crossovers and bifurcations and finally calculating local and global tortuosity. The last stage is based on a circular mask that is put on every skeleton point of retinal vessels. While the skeleton of vessel splits the circle in each position, the local tortuosity is considered to be the bigger to smaller area ratio. The proposed... 

    Toward an intelligent approach for determination of saturation pressure of crude oil

    , Article Fuel Processing Technology ; Volume 115 , 2013 , Pages 201-214 ; 03783820 (ISSN) Farasat, A ; Shokrollahi, A ; Arabloo, M ; Gharagheizi, F ; Mohammadi, A. H ; Sharif University of Technology
    Bubble point pressure is a crucial PVT parameter of reservoir fluids, which has a significant effect on oil field development strategies, reservoir evaluation and production calculations. This communication presents a new mathematical model to calculate the saturation pressures of crude oils as a function of temperature, hydrocarbon and non-hydrocarbon reservoir fluid compositions, and characteristics of the heptane-plus fraction. The model was developed and tested using a total set of 130 experimentally measured compositions and saturation pressures of crude oil samples from different geographical locations covering wide ranges of crude oil properties and reservoir temperatures. In-depth... 

    Preconcentration and determination of carbaryl and carbofuran in water samples using ionic liquids and in situ solvent formation microextraction

    , Article Analytical Methods ; Volume 5, Issue 9 , 2013 , Pages 2406-2412 ; 17599660 (ISSN) Tehrani, M. S ; Givianrad, M. H ; Akhoundi, L ; Akhoundi, M ; Sharif University of Technology
    In the present work, a novel microextraction method named in situ solvent formation microextraction (ISFME) using ionic liquids (ILs) for preconcentration of carbaryl and carbofuran in water samples is introduced. In this method, a small amount of sodium hexafluorophosphate (NaPF6), as an ion pairing agent, was added to a sample solution containing a small quantity of 1-hexyl-3-methylimidazolium tetrafluoroborate [Hmim][BF4] as a hydrophobic ionic liquid. A cloudy solution formed as a result of formation of fine droplets of 1-hexyl-3-methylimidazolium hexafluorophosphate [Hmim][PF 6]. After centrifugation, the fine droplets of the extractant phase settled to the bottom of the conical-bottom... 

    Sensitivity analysis of jacket-type offshore platforms under extreme waves

    , Article Journal of Constructional Steel Research ; Volume 83 , 2013 , Pages 147-155 ; 0143974X (ISSN) Hezarjaribi, M ; Bahaari, M. R ; Bagheri, V ; Ebrahimian, H ; Sharif University of Technology
    Jacket-type offshore platforms play an important role in oil and gas industries in shallow and intermediate water depths such as Persian Gulf region. Such important structures need accurate considerations in analysis, design and assessment procedures. In this paper, nonlinear response of jacket-type platforms against extreme waves is examined utilizing sensitivity analyses. Results of this paper can reduce the number of random variables and consequently the computational effort in reliability analysis of jacket platforms, noticeably. Effects of foundation modeling have been neglected in majority of researches on the response of jacket platforms against wave loads. As nonlinear response of... 

    Formulation of soil angle of shearing resistance using a hybrid GP and OLS method

    , Article Engineering with Computers ; Volume 29, Issue 1 , September , 2013 , Pages 37-53 ; 01770667 (ISSN) Mousavi, S. M ; Alavi, A.H ; Mollahasani, A ; Gandomi, A. H ; Arab Esmaeili, M ; Sharif University of Technology
    In the present study, a prediction model was derived for the effective angle of shearing resistance (φ′) of soils using a novel hybrid method coupling genetic programming (GP) and orthogonal least squares algorithm (OLS). The proposed nonlinear model relates φ′ to the basic soil physical properties. A comprehensive experimental database of consolidated-drained triaxial tests was used to develop the model. Traditional GP and least square regression analyses were performed to benchmark the GP/OLS model against classical approaches. Validity of the model was verified using a part of laboratory data that were not involved in the calibration process. The statistical measures of correlation... 

    Properties of functional brain networks correlate frequency of psychogenic non-epileptic seizures

    , Article Frontiers in Human Neuroscience ; Issue DEC , 2012 ; 16625161 (ISSN) Barzegaran, E ; Joudaki, A ; Jalili, M ; Rossetti, A. O ; Frackowiak, R. S ; Knyazeva, M. G ; Sharif University of Technology
    Frontiers Media S. A  2012
    Abnormalities in the topology of brain networks may be an important feature and etiological factor for psychogenic non-epileptic seizures (PNES). To explore this possibility, we applied a graph theoretical approach to functional networks based on resting state EEGs from 13 PNES patients and 13 age- and gender-matched controls. The networks were extracted from Laplacian-transformed time-series by a cross-correlation method. PNES patients showed close to normal local and global connectivity and small-world structure, estimated with clustering coefficient, modularity, global efficiency, and small-worldness metrics, respectively. Yet the number of PNES attacks per month correlated with a... 

    Prediction of reaction force on external indenter in cell injection experiment using support vector machine technique

    , Article ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE) ; Volume 2 , 2012 , Pages 537-543 ; 9780791845189 (ISBN) Abbasi, A. A ; Ahmadian, M. T ; Sharif University of Technology
    Evaluation of the reaction force on a tool which is used for exertion of force on biomaterials such as biological cells or soft tissues has applications in virtual reality based medical simulators or haptic tools. In this study, two least square based support vector machine (SVM) models have been constructed to predict the indentation or reaction force on mouse oocyte and embryo cells in cell injection experiment. Inputs of these two models are geometrical parameters of indented cell, namely dimple radius (a), dimple depth (w) and radius of the semicircular curve (R). Experimental data for calibration and prediction of the models have been captured from literatures. The performance of the... 

    Effect of deep breath on the correlation between the wrist and finger photoplethysmograms

    , Article 2012 19th Iranian Conference of Biomedical Engineering, ICBME 2012 ; 2012 , Pages 135-138 ; 9781467331302 (ISBN) Keikhosravi, A ; Zahedi, E ; Sharif University of Technology
    In this paper, a special probe is designed using an array of photodiodes and a 960 nm LED for recording the wrist photoplethysmogram (PPG). The design is based on Monte-Carlo simulation of light propagation in tissues. Two series of experiments were carried-out: normal breathing and deep breathing. In both experiments, finger and wrist PPG were simultaneously recorded from the index finger. In the first series of experiment, signals from 9 subjects were recorded and the correlation coefficient for the raw signals (AC+DC), the AC and DC components of wrist and finger PPG were (62.5% ± 12.1%), (91.2% ± 6.9%) and (61% ± 13.4%) respectively. In the second series of experiment (deep breathing),...