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shariat--mohammad
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Upgrade Feasibility Studyof a Class D Gas Turbine
, M.Sc. Thesis Sharif University of Technology ; Ghorbanian, Kaveh (Supervisor)
Abstract
The purpose of this thesis is to investigate and identify the performance of a class D gas turbine and improve its efficiency.This thesis contains three parts: first part is to choose a specific engine in class D, for our case “Centaur 40”, then this engine, model and validate by GASTURB with existed data.Second part is tosurvey methods of pgradedemonstrated gas turbine with regard to upgraded Solar Centaur 40 “Taurus 60” using the FORTRAN code base on Stage Stacking method.Finally,the last part of this thesis is to investigate Compressor-Turbine matching. In this part the matching zone of the original and upgraded gas turbines are determined and effect of upgrading on matching zone is...
On Graph Partitioning Algorithms And It’s Applications in Image Segmentation
, M.Sc. Thesis Sharif University of Technology ; Daneshgar, Amir (Supervisor)
Abstract
The problem of partitioning vertices of a graph has been studied with different formulations according to their application. In this thesis we try to review some of these formulations and existing algorithms. In addition we try to investigate the correct definition for a specific application in image processing, namely image segmentation. At the end, we propose a new algorithm for partitioning vertices of a weighted graph according to the mentioned application and compare its performance with some similar algorithms
A learning automata and clustering-based routing protocol for named data networking
, Article Telecommunication Systems ; 2016 , Pages 1-21 ; 10184864 (ISSN) ; Movaghar, A ; Hoseinzadeh, M ; Sharif University of Technology
Springer New York LLC
2016
Abstract
Named Data Networking (NDN) is a new information-centric networking architecture in which data or content is identified by a unique name and saved pieces of the content are used in the cache of routers. Certainly, routing is one of the major challenges in these networks. In NDN, to achieve the required data for users, interest messages containing the names of data are sent. Because the source and destination addresses are not included in this package, routers forward them using the names that carried in packages. This forward will continue until the interest package is served. In this paper, we propose a routing algorithm for NDN. The purpose of this protocol is to choose a path with the...
Simulation of Heat & Momentum Balance of Vacuum Bottom Flow in Thermal Cracking Fired Heater
, M.Sc. Thesis Sharif University of Technology ; Farhadi, Fathollah (Supervisor)
Abstract
The delayed coking process is one of the common thermal process technique that used to improve the quality of heavy oil. In this process, heavy feeds such as vacuum residues have been heated in the furnace to temperatures up to the 480-500 °C. For the cracking reactions the heated feed have been sent to the drum that is placed after the furnace. Since the reactions begin inside the furnace and coke is one of the products, deposited on the wall of the tube. With the deposition of coke on the tube wall and the reduction of heat transfer, the temperature of the tube have been increased with the increasing of the flame temperature to save constant heat flux. Therefore, the study of thermal...
A learning automata and clustering-based routing protocol for named data networking
, Article Telecommunication Systems ; Volume 65, Issue 1 , 2017 , Pages 9-29 ; 10184864 (ISSN) ; Movaghar, A ; Hoseinzadeh, M ; Sharif University of Technology
Springer New York LLC
2017
Abstract
Named data networking (NDN) is a new information-centric networking architecture in which data or content is identified by a unique name and saved pieces of the content are used in the cache of routers. Certainly, routing is one of the major challenges in these networks. In NDN, to achieve the required data for users, interest messages containing the names of data are sent. Because the source and destination addresses are not included in this package, routers forward them using the names that carried in packages. This forward will continue until the interest package is served. In this paper, we propose a routing algorithm for NDN. The purpose of this protocol is to choose a path with the...
TSRN: A tabu search-based routing protocol for named data networking
, Article Wireless Personal Communications ; Volume 101, Issue 3 , 2018 , Pages 1411-1428 ; 09296212 (ISSN) ; Movaghar, A ; Hosseinzadeh, M ; Sharif University of Technology
Springer New York LLC
2018
Abstract
Information-centric network (ICN) has become a basic research topic with regard to the future architecture of the Internet. Storage and routing data is an important feature of ICN, as it improves network performance and content distribution. One of the challenges in this type of network is the routing problem. The objective of this paper is to propose a routing algorithm in the named data network. Owing to the impressive results presented by the enhanced heuristic methods, tabu search has been selected to develop the proposed algorithm. This work has been carried out in five major steps, Creating the initial solution, The mechanisms of generating a neighborhood, Evaluating the neighbor...
Clustering and outlier detection using isoperimetric number of trees
, Article Pattern Recognition ; Volume 46, Issue 12 , December , 2013 , Pages 3371-3382 ; 00313203 (ISSN) ; Javadi, R ; Shariat Razavi, S. B ; Sharif University of Technology
2013
Abstract
We propose a graph-based data clustering algorithm which is based on exact clustering of a minimum spanning tree in terms of a minimum isoperimetry criteria. We show that our basic clustering algorithm runs in O(nlogn) and with post-processing in almost O(nlogn) (average case) and O(n2) (worst case) time where n is the size of the data-set. It is also shown that our generalized graph model, which also allows the use of potentials at vertices, can be used to extract an extra piece of information related to anomalous data patterns and outliers. In this regard, we propose an algorithm that extracts outliers in parallel to data clustering. We also provide a comparative performance analysis of...
The effect of chemical functional groups and salt concentration on performance of single-layer graphene membrane in water desalination process: A molecular dynamics simulation study
, Article Journal of Molecular Liquids ; Volume 301 , 2020 ; Moosavi, A ; Bagheri Sarvestani, A ; Shariat, M ; Sharif University of Technology
Elsevier B.V
2020
Abstract
In this study, the mechanisms of passing water and salt ions through nanoporous single-layer graphene membrane are simulated using classical molecular dynamics. The effects of functional groups placed in nanopores and feed water's salt concentration on water desalination are investigated. In order to understand the role of functional groups in desalination process, Methyl, Ethyl and a combination of Fluorine and Hydrogen molecules are distributed around the nanopores. In all cases, different number of functional molecules is employed in order to find an optimum distribution of the groups at hand. The results show that an appropriate distribution of Alkyl groups can properly stop the salt...
Sensitivity and generalized analytical sensitivity expressions for quantitative analysis using convolutional neural networks
, Article Analytica Chimica Acta ; 2021 ; 00032670 (ISSN) ; Kirsanov, D ; Olivieri, A. C ; Parastar, H ; Sharif University of Technology
Elsevier B.V
2021
Abstract
In recent years, convolutional neural networks and deep neural networks have been used extensively in various fields of analytical chemistry. The use of these models for calibration tasks has been highly effective; however, few reports have been published on their properties and characteristics of analytical figures of merit. Currently, most performance measures for these types of networks only incorporate some function of prediction error. While useful, these measures are incomplete and cannot be used as an objective comparison among different models. In this report, a new method for calculating the sensitivity of any type of neural network is proposed and studied on both simulated and real...
Sensitivity and generalized analytical sensitivity expressions for quantitative analysis using convolutional neural networks
, Article Analytica Chimica Acta ; Volume 1192 , 2022 ; 00032670 (ISSN) ; Kirsanov, D ; Olivieri, A. C ; Parastar, H ; Sharif University of Technology
Elsevier B.V
2022
Abstract
In recent years, convolutional neural networks and deep neural networks have been used extensively in various fields of analytical chemistry. The use of these models for calibration tasks has been highly effective; however, few reports have been published on their properties and characteristics of analytical figures of merit. Currently, most performance measures for these types of networks only incorporate some function of prediction error. While useful, these measures are incomplete and cannot be used as an objective comparison among different models. In this report, a new method for calculating the sensitivity of any type of neural network is proposed and studied on both simulated and real...
Gravitational Lensing of Gravitational Waves
, M.Sc. Thesis Sharif University of Technology ; Baghram, Shant (Supervisor) ; Rahvar, Sohrab (Supervisor)
Abstract
The discovery of gravitational waves by LIGO has undoubtedly opened a new window on our observations of the universe. In this way, valuable observational information can be obtained from near astrophysical sources to distant cosmic structures. In addition to the source of gravitational wave propagation, with the help of phenomena such as the magnification of light intensity by intermediate objects in the path of the gravitational wave to the observer, useful information can be obtained from the distribution of cosmic matter. The study of this effect is possible with the help of frequency changes per unit time. Therefore, what can be measured are the magnification effects of the...
The effect of nanopores geometry on desalination of single-layer graphene-based membranes: A molecular dynamics study
, Article Journal of Molecular Liquids ; Volume 339 , 2021 ; 01677322 (ISSN) ; Chogani, A ; Shariat, M ; Moosavi, A ; Kariminasab, H ; Sharif University of Technology
Elsevier B.V
2021
Abstract
The water desalination process using nanoporous single-layer graphene membranes is simulated through classical molecular dynamics. The effect of nanopores shapes on the capacity of the membrane for filtration of water is investigated. According to the results, the geometry of the nanopores considerably affects the performance of the membrane and can completely change the water flow rate and salt rejection. The results reveal that the effective area of the nanopores plays a critical role and for a better understanding of the impact of this parameter, aspect ratio and the equal diameter of noncircular pores based on different methods such as equal area, equal perimeter, and hydraulic diameter...
Towards a self-adaptive service-oriented methodology based on extended SOMA
, Article Frontiers of Information Technology & Electronic Engineering ; Volume 16, Issue 1 , January 2015 , Pages 43-69 ; Moaven, S ; Habibi, J ; Beigi, G ; Naser-Shariat, M ; Sharif University of Technology
January 2015
Abstract
We propose a self-adaptive process (SAP) that maintains the software architecture quality using the MAPE-K standard model. The proposed process can be plugged into various software development processes and service-oriented methodologies due to its explicitly defined inputs and outputs. To this aim, the proposed SAP is integrated with the service-oriented modeling and application (SOMA) methodology in a two-layered structure to create a novel methodology, named self-adaptive service-oriented architecture methodology (SASOAM), which provides a semi-automatic self-aware method by the composition of architectural tactics. Moreover, the maintenance activity of SOMA is improved using...
Design and Manufacturing of an Exoskeleton Mechanism for Lower Limbs with Active and Semi-Passive Joints According to Biomechanical Principles
, M.Sc. Thesis Sharif University of Technology ; Zohoor, Hassan (Supervisor) ; Firoozbakhsh, Keikhosrow (Co-Advisor) ; Vossoughi, Gholamreza (Co-Advisor)
Abstract
Today, people living in all over the world are faced with the arrival of Biomechanics and Human need of rehabilitation equipment is growing. Wearable robots have created a new field in service robots’ world. Unlike industrial robots, these robots are strongly interacting with humans. Physical interaction between humans and robots considered one of the exciting and challenging research topics. With attention to this issue, research projects have been started in the department of mechanical engineering of Sharif University of technology to design, manufacture and control a wearable robot with few degrees of freedom used in the lower joints. In this thesis, initially focused on the conceptual...
Towards a self-adaptive service-oriented methodology based on extended SOMA
, Article Frontiers of Information Technology and Electronic Engineering ; Volume 16, Issue 1 , 2015 , Pages 43-69 ; 20959184 (ISSN) ; Moaven, S ; Habibi, J ; Beigi, G ; Naser Shariat, M ; Sharif University of Technology
2015
Abstract
We propose a self-adaptive process (SAP) that maintains the software architecture quality using the MAPE-K standard model. The proposed process can be plugged into various software development processes and service-oriented methodologies due to its explicitly defined inputs and outputs. To this aim, the proposed SAP is integrated with the service-oriented modeling and application (SOMA) methodology in a two-layered structure to create a novel methodology, named self-adaptive service-oriented architecture methodology (SASOAM), which provides a semi-automatic self-aware method by the composition of architectural tactics. Moreover, the maintenance activity of SOMA is improved using...
Towards a self-adaptive service-oriented methodology based on extended SOMA
, Article Journal of Zhejiang University: Science C ; Volume 16, Issue 1 , 2015 , Pages 43-69 ; 18691951 (ISSN) ; Moaven, S ; Habibi, J ; Beigi, G ; Naser Shariat, M ; Sharif University of Technology
2015
Abstract
We propose a self-adaptive process (SAP) that maintains the software architecture quality using the MAPE-K standard model. The proposed process can be plugged into various software development processes and service-oriented methodologies due to its explicitly defined inputs and outputs. To this aim, the proposed SAP is integrated with the service-oriented modeling and application (SOMA) methodology in a two-layered structure to create a novel methodology, named self-adaptive service-oriented architecture methodology (SASOAM), which provides a semi-automatic self-aware method by the composition of architectural tactics. Moreover, the maintenance activity of SOMA is improved using...
Hybrid AC/DC Microgrid Planning
, M.Sc. Thesis Sharif University of Technology ; Fotouhi Firuzabad, Mahmoud (Supervisor) ; Rajabi Ghahnavie, Abbas (Co-Advisor)
Abstract
Nowadays, due to the increasing importance and penetration of microgrids, solving the microgrid optimal sizing problem has become more important. The current utility grid and conventional energy sources are mainly ac, however, increasing rate of the replacement of the ac load with dc load lead to a more efficient dc system. So choosing the optimal type of microgrid as a way to increase efficiency of these systems would be a serious issue. This thesis establishes a planning model which finds the optimal size and type of a microgrid to minimize total cost. Total cost includes investment, operation and reliability cost of the microgrid. Sizes of DGs, converters and transformer linking the...
Comparison between several methods of PPM demodulation based on iterative techniques
, Article Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) ; Volume 3124 , 2004 , Pages 554-559 ; 03029743 (ISSN); 3540225714 (ISBN); 9783540225713 (ISBN) ; Ferdosizadeh, M ; Abdoli, M. J ; Makouei, B ; Yazdanpanah, A ; Marvasti, F ; Sharif University of Technology
Springer Verlag
2004
Abstract
In this paper we examine demodulation methods for nonuniform Pulse Position Modulation (PPM), which is generated by the crossings of a modulating signal with a sawtooth wave. Here, we are interested in PPM at the Nyquist rate and illustrate the efficiency of the iterative methods. Several iterative methods such as Wiley/Marvasti, Time-varying, adaptive weight, Zero-order-hold, Voronoi, linear interpolation algorithms are discussed, where the PPM demodulation is converted as a nonuniform sampling reconstruction problem. Also another approach called the inverse system approach is introduced and the performance of the two algorithms is assessed. © Springer-Verlag 2004
Phase behavior and rheology of emulsions in an alkaline/cosolvent/crude oil/brine system
, Article Petroleum Science and Technology ; Volume 34, Issue 3 , 2016 , Pages 207-215 ; 10916466 (ISSN) ; Hemmati, M ; Shariat Panahi, H ; Masihi, M ; Karam Beigi, M. S ; Sharif University of Technology
Taylor and Francis Inc
2016
Abstract
Phase behavior of active crude oil/alkaline was systematically studied in the presence of cosolvents. For this purpose, several factors have been considered: alkaline concentration, oil concentration, and type of brine. The best composition was used to generate emulsion for rheology and displacement tests. Furthermore, precipitation of alkaline was eliminated by its synergy with EDTA. Next, rheology of emulsion was analyzed by which a Power law model was developed that indicates non-Newtonian behavior of emulsion. Moreover, the viscosity of emulsion was reduced by the addition of cosolvent as well as by the increase of alkaline concentration. Finally, the best formulation (containing...
Electromechanical resonator based on electrostatically actuated graphene-doped PVP nanofibers
, Article Nanotechnology ; Volume 24, Issue 13 , 2013 ; 09574484 (ISSN) ; Mohammadi, S ; Zad, A. I ; Sarvari, R ; Shariat Panahi, S. P ; Jokar, E ; Sharif University of Technology
2013
Abstract
In this paper we present experimental results describing electrical readout of the mechanical vibratory response of graphene-doped fibers by employing electrical actuation. For a fiber resonator with an approximate radius of 850 nm and length of 100 m, we observed a resonance frequency around 580 kHz with a quality factor (Q) of about 2511 in air at ambient conditions. Through the use of finite element simulations, we show that the reported frequency of resonance is relevant. We also show that the resonance frequency of the fiber resonators decreases as the bias potential is increased due to the electrostatic spring-softening effect