Loading...
Search for: panahi-velashedi--behnam
0.143 seconds

    Fabrication of Vascularized Scaffold Containing Cardiac Tissue-derived Decellularized Extracellular Matrix Using Bioprinter

    , M.Sc. Thesis Sharif University of Technology Panahi Velashedi, Behnam (Author) ; Mashayekhan, Shohreh (Supervisor)
    Abstract
    In this study, a new bioink was introduced for the production of tubular tissue structures for cardiac tissue engineering by bioprinter using the FRESH (Freeform Reversible Embedding of Suspended Hydrogels) method. The novel bioink that we used was a combination of cardiac extracellular matrix (cECM) and oxidized alginate. The cardiac extracellular matrix was used to increase the biomimetic of the printed structures to the actual tissue of the body, and also to create sites for cell adhesion, and to improve cell growth and survival. We used alginate oxide (oxidation degree: 5%) to increase the mechanical properties of the tissue. Alginate oxidation has been due to extracellular matrix (ECM)... 

    Accurate detection and recognition of dirty vehicle plate numbers for high-speed applications

    , Article IEEE Transactions on Intelligent Transportation Systems ; Volume 18, Issue 4 , 2017 , Pages 767-779 ; 15249050 (ISSN) Panahi, R ; Gholampour, I ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2017
    Abstract
    This paper presents an online highly accurate system for automatic number plate recognition (ANPR) that can be used as a basis for many real-world ITS applications. The system is designed to deal with unclear vehicle plates, variations in weather and lighting conditions, different traffic situations, and high-speed vehicles. This paper addresses various issues by presenting proper hardware platforms along with real-Time, robust, and innovative algorithms. We have collected huge and highly inclusive data sets of Persian license plates for evaluations, comparisons, and improvement of various involved algorithms. The data sets include images that were captured from crossroads, streets, and... 

    Large scale image search

    , M.Sc. Thesis Sharif University of Technology Panahi, Soraya (Author) ; Moghaddasi, Reza (Supervisor)
    Abstract
    Searching for images of the same object or scene in a large number of images is a major problem in computer vision. It has many applications specially in the search engines.For the goal of efficient image search, we need descriptors that are not only discriminative, but also short and need small amount of memory.In this thesis we analyze the image search methods in two categories: The first methods are based on converting the existed descriptors such as gist into a compact binary code. The second methods are based on building short descriptors, especially by some modifications in the framework of bag of features descriptor.Finally we will introduce a novel descriptor "bag of codes" which... 

    Chemical Modification of Glassy Carbon Electrode by Carbon Nanostructures/Conductive Polymers Composites and Its Application in The Study of Electrochemical Behaviour and Determination of Salbutamol and Isoprenaline

    , M.Sc. Thesis Sharif University of Technology Panahi, Saba (Author) ; Shahrokhian, Saeed (Supervisor)
    Abstract
    In the first part of thesis, the electropolymerization of pyrrole was performed in the presence of new coccine (NC) as a dopant anion on the surface of the electrode precoated with SWCNT. The modified electrode was used to study the voltammetric response of salbutamol (SAL). The results showed a remarkable increase in the anodic peak current of SAL in comparison to the bare GCE. The surface morphology PPY/CNT/GCE was thoroughly characterized by scanning electron microscopy (SEM) and cyclic voltammetry (CV) techniques. Under the optimized analysis conditions, the modified electrode showed two linear dynamic ranges of 0.02 – 0.1 μM and 0.1-10 μM with a detection limit of 6 nM for the... 

    Resource Allocation in Multi-project Scheduling with Resource Transfer Time and Cost

    , M.Sc. Thesis Sharif University of Technology Panahi, Yousef (Author) ; Shadrokh, Shahram (Supervisor)
    Abstract
    The project scheduling problem is one of the classic problems in project management that includes a range of optimization problems. One of the limitations we face in project scheduling problem is the resource constraint limitation. In many studies in the literature review, problems are based on the false assumption that a resource can be transferred between activities of a project or different projects without spending time and cost. The resource availability method in many fundamental researches in the context of resource constrained project scheduling problem (RCPSP) is considered as resource investment problems (RIP); while in many real world projects resources are rented for projects and... 

    Examination of a solar desalination system equipped with an air bubble column humidifier, evacuated tube collectors and thermosyphon heat pipes

    , Article Desalination ; Volume 397 , 2016 , Pages 30-37 ; 00119164 (ISSN) Behnam, P ; Behshad Shafii, M ; Sharif University of Technology
    Elsevier  2016
    Abstract
    In this paper, the performance of a novel HDH solar desalination system equipped with a combination of heat pipe (HP), evacuated tube collector (ETC) and air bubble column humidifier is experimentally investigated. This novel HDH system uses advantages of ETC-HP as a highly efficient thermal absorption and conductor device, and at the same time employs the advantages of an air bubble column humidifier, i.e. high interface area and effective mixing in order to heat the water and humidify the air, respectively. The effects of various parameters including incoming air flow rate into the humidifier, initial depth of water in the humidifier, and adding fluids such as oil and water in the space... 

    Development a Double Cell Triaxial Permeameter for Measuring Saturated Hydraulic Conductivity of Highly Deformable Soils

    , M.Sc. Thesis Sharif University of Technology Ali Panahi, Pouya (Author) ; Sadeghi, Hamed (Supervisor)
    Abstract
    The measurement of saturated hydraulic conductivity in conventional methods is based on the assumption of non-deformable porous media. However, this assumption is violated in most cases, especially when dealing with highly deformable soils such as collapsible and expansive soils. An alternative is to use flexible wall triaxial devices, yet the deformation characteristics during wetting and sample saturation are missed. This issue is of great importance in soils with considerable amount of volume changes (e.g., problematic soils). It should be noted that errors included in measuring sample volume changes, water inflow/outflow rates, and the creation of sidewall leakage are essential factors... 

    MRI-PET image fusion based on NSCT transform using local energy and local variance fusion rules

    , Article Journal of Medical Engineering and Technology ; Vol. 38, issue. 4 , 2014 , p. 211-219 Amini, N ; Fatemizadeh, E ; Behnam, H ; Sharif University of Technology
    2014
    Abstract
    Image fusion means to integrate information from one image to another image. Medical images according to the nature of the images are divided into structural (such as CT and MRI) and functional (such as SPECT, PET). This article fused MRI and PET images and the purpose is adding structural information from MRI to functional information of PET images. The images decomposed with Nonsubsampled Contourlet Transform and then two images were fused with applying fusion rules. The coefficients of the low frequency band are combined by a maximal energy rule and coefficients of the high frequency bands are combined by a maximal variance rule. Finally, visual and quantitative criteria were used to... 

    A robust dual source level set method for three-dimensional echocardiography image segmentation

    , Article Journal of Theoretical and Applied Information Technology ; Volume 95, Issue 21 , 2017 , Pages 5701-5710 ; 19928645 (ISSN) Sahba, N ; Fatemizadeh, E ; Behnam, H ; Sharif University of Technology
    2017
    Abstract
    Echocardiography as a common place device has been widely used for diagnosis. Segmentation of left ventricle just using the standard level set formulation based on the magnitude of intensity cannot restrict the contour evolution completely due to the lack of sharp edges. This paper aims to introduce a robust method for segmentation of three-dimensional echocardiography images based on two boundary maps namely distance map and probabilistic map as stopping criteria of contour evolution which are extracted using two different approaches. The distance map is extracted by applying Free Form Deformation (FFD) method on manually determined landmarks of initial spherical volume to register the... 

    An optimized probabilistic edge based level set method for left ventricle segmentation in echocardiography images

    , Article Biomedical Research (India) ; Volume 28, Issue 8 , 2017 , Pages 3788-3793 ; 0970938X (ISSN) Sahba, N ; Fatemizadeh, E ; Behnam, H ; Sharif University of Technology
    Scientific Publishers of India  2017
    Abstract
    In this paper, an efficient approach for ultrasonic object segmentation with special application for left ventricle segmentation in echocardiography images is proposed. At first, an efficient hybrid trend for ultrasonic image edge detection is suggested. Then, a modified level set approach is introduced based on the extracted edges and the computed probabilistic map as the stopping criteria for the contour evolution. Both synthetic and clinical images are utilized as validation measures with respect to the prior techniques which indicate outperform results quantitatively and qualitatively. Left ventricle segmentation using proposed method illustrates expert-approved performance, providing a... 

    A review on state-of-the-art applications of data-driven methods in desalination systems

    , Article Desalination ; Volume 532 , 2022 ; 00119164 (ISSN) Behnam, P ; Faegh, M ; Khiadani, M ; Sharif University of Technology
    Elsevier B.V  2022
    Abstract
    The substitution of conventional mathematical models with fast and accurate modeling tools can result in the further development of desalination technologies and tackling the need for freshwater. Due to the great capability of data-driven methods in analyzing complex systems, several attempts have been made to study various desalination systems using data-driven approaches. In this state-of-the-art review, the application of various artificial intelligence and design of experiment data-driven methods for analyzing different desalination technologies have been thoroughly investigated. According to the applications of data-driven methods in the field of desalination, the reviewed... 

    Enhanced electrochemical activity of a hollow carbon sphere/polyaniline-based electrochemical biosensor for HBV DNA marker detection

    , Article ACS Biomaterials Science and Engineering ; Volume 5, Issue 5 , 2019 , Pages 2587-2594 ; 23739878 (ISSN) Salimian, R ; Shahrokhian, S ; Panahi, S ; Sharif University of Technology
    American Chemical Society  2019
    Abstract
    Herein, we present a novel, simple, and ultrasensitive electrochemical DNA (E-DNA) sensor based on hollow carbon spheres (HCS) decorated with polyaniline (PANI). A thiolated 21-mer oligonucleotide, characteristic of HBV DNA, is immobilized via electrodeposited gold nanoparticles on HCS-PANI. Cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS) are used to characterize the electrochemical properties of the prepared nanocomposite. Scanning electron microscopy is employed to investigate the morphological texture of the fabricated modifier. An enhanced intrinsic signal of PANI is probed to evaluate the biosensing ability of the prepared... 

    Nonlinear forced vibration analysis of micro-rotating shaft–disk systems through a formulation based on the nonlocal strain gradient theory

    , Article Archives of Civil and Mechanical Engineering ; Volume 23, Issue 2 , 2023 ; 16449665 (ISSN) Panahi, R ; Asghari, M ; Borjalilou, V ; Sharif University of Technology
    Springer Science and Business Media Deutschland GmbH  2023
    Abstract
    The paper presents an upgraded size-dependent formulation for micro-rotating shaft–disks system to study their nonlinear forced vibration behavior. The novel formulation is based on the nonlocal strain gradient theory (NSGT). To achieve this goal, first of all, by incorporating the geometrical nonlinearity within the Rayleigh beam theory, the governing equations of the lateral motion of the system are derived by the Hamilton principle and then converted into a complex form. By defining some dimensionless parameters, the normalized form of the complex governing equation is also extracted. In the next step, the Galerkin method is implemented to establish an infinite set of ordinary... 

    Error Resilient Coding of H.264 for Wireless Networks

    , M.Sc. Thesis Sharif University of Technology Agahian Panahi, Mohammad (Author) ; Kasaei, Shohreh (Supervisor)
    Abstract
    Nowadays, wireless communications for multimedia purposes is widely spreaded especially due to video communication demands. One of important considerations in this area is to receive video stream with less effect of errors related to transition channel as well as optimal utilization of bandwidth. The H.264 is exploited as the most efficient video compression standard and because of its predictive nature of encoder and decoder, it is very sensitive to error propagation, so error resilient technics should be applied along with the video compression to reduce the visual impacts of error occurrence and propagation. In this thesis existing methods of video error resilience, video quality measures... 

    Guarding a Terrain by Watchtowers

    , M.Sc. Thesis Sharif University of Technology Panahi Shahri, Masoume (Author) ; Zarei, Alireza (Supervisor)
    Abstract
    Guarding terrains(or covering terrains) is a well known problem in the field of visibility and computational geometry. The aim of this problem is to select a minimal set of elements (such as points on terrain, line segment, points above terrain ,...),as guard set, such that every point of the terrain is visible from at least one member of the guard set.
    This problem was introduced in 2-dimensions as art gallery problem. Various types of this problem have been defiend and studied in the literature. Guarding 3-dimensional terrains is an example of this problem. In 3-dimentional case, the guarded terrain can be modeled with triangulated irregullar network(TIN), as one of the surface models,... 

    Forced Vibration Analysis of Rotating Micro-Shaft Based on the Non-local Strain Gradient Theory

    , M.Sc. Thesis Sharif University of Technology Panahi Dorcheh, Ramin (Author) ; Asghari, Mohsen (Supervisor)
    Abstract
    Nowadays, with progresses made in manufacturing technologies, it is possible to produce micro-scale products such as micro-electromechanical systems. Micro-motors are one type of these systems that can be used in such applications as power supply of electronic devices. To achieve a better performance, these systems must rotate at high rotational speeds (about one million revolutions per minute). At such a high rotational speed, vibrational analysis is highly crucial. The results of recent studies indicate the inability of classical theories of continuum mechanics to analyze the behavior of these micro systems. Therefore, in this research, the rotor of micro-motors are modeled using the... 

    The Effect of Shear Connectors in the Protected Zone of the Connection of Composite Beams to Steel Columns

    , M.Sc. Thesis Sharif University of Technology Panahi, Mohsen (Author) ; Kazemi, Mohammad Taghi (Supervisor)
    Abstract
    The use of concrete and steel composite structural systems has been extensively studied both numerically and experimentally. Composite concrete and steel beams consist of a steel beam on which the concrete slab is constructed using shear connections. The performance of concrete slabs and steel beams in steel composite concrete structures is generally provided by welded shear connectors on the upper flange of the steel beam. In this study, a more accurate model in numerical form will be conducted to investigate the effect of shear connectors installed in the composite beam in the critical area of beam to column connection, which is considered as a protected zone. The main objective of this... 

    Automatic segmentation of brain MRI in high-dimensional local and non-local feature space based on sparse representation

    , Article Magnetic Resonance Imaging ; Volume 31, Issue 5 , 2013 , Pages 733-741 ; 0730725X (ISSN) Khalilzadeh, M. M ; Fatemizadeh, E ; Behnam, H ; Sharif University of Technology
    2013
    Abstract
    Automatic extraction of the varying regions of magnetic resonance images is required as a prior step in a diagnostic intelligent system. The sparsest representation and high-dimensional feature are provided based on learned dictionary. The classification is done by employing the technique that computes the reconstruction error locally and non-locally of each pixel. The acquired results from the real and simulated images are superior to the best MRI segmentation method with regard to the stability advantages. In addition, it is segmented exactly through a formula taken from the distance and sparse factors. Also, it is done automatically taking sparse factor in unsupervised clustering methods... 

    Adaptive sparse representation for MRI noise removal

    , Article Biomedical Engineering - Applications, Basis and Communications ; Volume 24, Issue 5 , October , 2012 , Pages 383-394 ; 10162372 (ISSN) Khalilzadeh, M. M ; Fatemizadeh, E ; Behnam, H ; Sharif University of Technology
    World Scientific  2012
    Abstract
    Sparse representation is a powerful tool for image processing, including noise removal. It is an effective method for Gaussian noise removal by taking advantage of a fixed and learned dictionary. In this study, the variable distribution of Rician noise is reduced in magnetic resonance (MR) images by sparse representation based on reconstruction error sets. Standard deviation of Gaussian noise is used to find these errors locally. The proposed method represents two formulas for local error calculation using standard deviation of noise. The acquired results from the real and simulated images are comparable, and in some cases, better than the best Rician noise removal method due to the... 

    Thermodynamic analysis of a novel combined power and refrigeration cycle comprising of EKalina and ejector refrigeration cycles

    , Article International Journal of Refrigeration ; Volume 104 , 2019 , Pages 291-301 ; 01407007 (ISSN) Behnam, P ; Faegh, M ; Shafii, M. B ; Sharif University of Technology
    Elsevier Ltd  2019
    Abstract
    A novel combined power and refrigeration cycle is introduced and analyzed from the thermodynamic standpoint. The proposed cycle is an integration of a Kalina cycle equipped with an ejector (EKalina) and an ejector refrigeration cycle (ERC). In order to enhance the overall cycle performance, the possibility of employing two-phase ejectors in combined power and refrigeration cycles is studied. A parametric analysis is conducted to investigate the effects of the key thermodynamic parameters namely turbine inlet pressure, split ratio, basic ammonia concentration, heat source and evaporator temperatures on the cycle performance. The developed model is also verified with available data and it is...