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rashidi--mehdi
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Security-Constraint Unit Commitment Using Classical And Hybrid Methods
, M.Sc. Thesis Sharif University of Technology ; Ehsan, Mehdi (Supervisor) ; Rashidi-Nejad, Masoud (Supervisor)
Abstract
Fast growing load in power systems associated with a large gap between heavy load and light load periods, generation scheduling and unit commitment (UC) problem has become a crucial issue in Scheduling time horizon. In a vertically integrated power system, unit commitment determines when to start-up or shut-down units and how to dispatch online generators over a given scheduling horizon in order to minimize the operating costs. Therefore main objective of this thesis is selected as unit commitment considering ramp rate, emission and line flow constraints. In this thesis four main works has been done: at first generation scheduling considering next hour is done which may yield to increase...
Evaluation of the Behaviorof Earth and Rockfill Dams during Construction and First Impounding using Instrumentation data and Numerical Modeling (Case Study: Dam Gavoshan)
, M.Sc. Thesis Sharif University of Technology ; Haeri, Mohsen (Supervisor)
Abstract
Monitoring is of particular importance after impounding and during dam operation. In all large dams, by installation of the required instruments the pore pressure, soil mass pressure and displacement during construction, first impounding and operation are measured, then the performance of dam will be analyzed and evaluated. The aim of this study is to evaluate the performance of the "Gavoshan" dam, which has an important role on agriculture development and drinking water supply at west part of Country. To reach this, the values resulting from instruments have been implemented by FLAC software, using "Back Analysis" method. However, this assessment is complete when "back analysis" method is...
Visual Simultaneous Localization and Mapping using an RGB-D Camera
, M.Sc. Thesis Sharif University of Technology ; Kasaei, Shohreh (Supervisor)
Abstract
Simultaneous localization and mapping (SLAM) is the action of detecting robot pose in an unknown environment and building the environment map by use of input data that captured from robot sensors. In visual SLAM, the input data for the robot, is limited to camera sensors. Nowadays, SLAM is one of the main challenges in robotic research.For autonomous action, we need robot pose in the map of the environment. The map production in the indoor environment, there is no GPS data, is one of the research issue in robotic community, in last decade. In this thesis, a new and efficient method is proposed for SLAM at the level of objects. The maps produced by state of the art methods don’t have a...
Joint Pricing and Inventory Control of Deteriorating Items under Conditions of Finite Production, Partial Backlogging and Lost Sale
, M.Sc. Thesis Sharif University of Technology ; Haji, Alireza (Supervisor)
Abstract
When demand for a product is price sensitive, pricing and lot sizing decisions are interdependent. Similarly, when a product is highly perishable, the demand may need to be backlogged to avoid costs due to deterioration, i.e., perishability and backlogging are complementary conditions.In this thesis we stablish two economic production quantity models for deteriorating items under conditions of finite production, exponential decay and partial backordering and lost sale. Two joint pricing inventory control models are developed for the problem by employing different modeling approaches over an infinite planning horizon. In two models, customer is viewed to be impatient and the fraction of the...
Numerical Investigation on Oil/Water Separation through Coalescence in Membrane Pores
, M.Sc. Thesis Sharif University of Technology ; Moosavi, Ali (Supervisor)
Abstract
Oil/water separation is an important field, not only for scientific research, but also for environmental, economic, and social issues. On the one hand, oily wastewater, resulting from industries such as steel, aluminum, food, textile, leather, petrochemical and metal finishing, has become the most common pollutant all over the world. On the other hand, frequent oil spill accidents are of great concern since the discharge can lead not only to serious environmental pollution, but also a great loss of energy.
In crude oil removing water is necessary due to reducing corrosion, increasing thermal values of fuels obtained from crude oil, preventing catalists from destruction by water and...
In crude oil removing water is necessary due to reducing corrosion, increasing thermal values of fuels obtained from crude oil, preventing catalists from destruction by water and...
Feasibility Study of Improving the Quality of PEM Images by Considering TOF and the DOI Correction
, M.Sc. Thesis Sharif University of Technology ; Hosseini, Abolfazle (Supervisor)
Abstract
Breast cancer is the most common type of cancer in women and the second cause of death among them. The chance of successful treatment would be significantly increased if the disease is diagnosed at its early stages. There are numerous methods to diagnose breast cancer. One of the most important methods is positron emission mammography (PEM).The main aim of this study is to investigate the feasibility of improving PEM images by considering the time of flight corrections and the penetration depth of the rays in the crystals.In this study, a commercial PEM system, Naviscan PEM, is simulated using the GATE software. In the first phase of the study, two opposing planar detectors are used to study...
Improving Speech-to-Speech Translation in Audio Dubbing Systems
, M.Sc. Thesis Sharif University of Technology ; Sameti, Hossein (Supervisor)
Abstract
Direct speech-to-speech translation, in which all compontents are trained jointly, is advantageous over cascaded approaches, because this method employs a simple yet effective pipeline to produce the outputs with a little inference time. Direct speech-to-speech translation models suffer from data scarcity issue, because they need parallel speech data in source and target languages. In this thesis, we present a novel direct speech-to-speech translation model to translate Persian speech to English, which is based on discrete speech units and uses a conformer-based encoder which is pretrained and a transformer-based causal decoder which uses relative position multi-head attention to do the task...
Evaluation of behaviors of earth and rockfill dams during construction and initial impounding using instrumentation data and numerical modeling
, Article Journal of Rock Mechanics and Geotechnical Engineering ; Volume 9, Issue 4 , 2017 , Pages 709-725 ; 16747755 (ISSN) ; Haeri, S. M ; Sharif University of Technology
2017
Abstract
In this study, the behavior of gavoshan dam was evaluated during construction and the first impounding. A two-dimensional (2D) numerical analysis was conducted based on a finite difference method on the largest cross-section of the dam using the results of instrument measurements and back analysis. These evaluations will be completed in the case that back analysis is carried out in order to control the degree of the accuracy and the level of confidence of the measured behavior since each of the measurements could be controlled by comparing it to the result obtained from the numerical model. Following that, by comparing the results of the numerical analysis with the measured values, it is...
Effect of Artificial Aging after Multi Directional Forging of Super Saturated AA 2024
, M.Sc. Thesis Sharif University of Technology ; Kazeminezhad, Mohsen (Supervisor)
Abstract
So far, much research has been done on severe plastic deformation of aluminum alloy 2024, but there is limited information on the effect of artificial aging for this alloy in the supersaturated, post-MDF state. As one of the methods of extreme plastic deformation process, multidirectional forging process (single pass) has been performed on different alloys including aluminum alloy 2024 at ambient temperature. Alloy 2024 was subjected to solution treatment at 500°C for 1 hour and multi-directional forging process was immediately performed on it. Then, at temperatures of 100, 140, 190, 240, and 290 °C, the aging process was continued for one hour until artificial aging. In order to investigate...
Numerical analysis and monitoring of an embankment dam during construction and first impounding case study: siah sang dam
, Article Scientia Iranica ; Volume 25, Issue 2A , 2018 , Pages 505-516 ; 10263098 (ISSN) ; Heidari, M ; Azizyan, Gh ; Sharif University of Technology
Sharif University of Technology
2018
Abstract
Monitoring embankment dams is of crucial importance. In earth dams, the pore pressures, earth pressures, and displacements occurring during construction and function are measured at the time of the first impounding and exploitation by installing essential instruments, and so the dam's performance is evaluated and analyzed. Scope of the present research is the evaluation of Siah-Sang Dam performance through the results of instruments and back analysis, conducted by FLAC software. The Mohr-Coulomb elasticplastic model has been considered as the behavioral model of the dam, and the effect of the upstream shell's materials deformation has been modeled at the time of the initial impounding....
A novel 3-dimentional ultra high precision positioning platform for micro machining cutting tools
, Article 3rd International Conference on Control, Automation and Robotics, ICCAR 2017, 22 April 2017 through 24 April 2017 ; 2017 , Pages 284-288 ; 9781509060870 (ISBN) ; Yadegari, A ; Rashidi, D ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2017
Abstract
Ultra-high precision machining is proposed by externally actuating the work piece in linear motions in the X-Y plane and linear motion in the Z-axis. To solve the problems in the machining process such as nonlinearity and low repeatability positioning accuracy of machining tools in a larger scale, a novel platform for cutting tools in micro machining based on electrostatic linear micromotors and piezoelectric stack actuator system is presented. © 2017 IEEE
Developing a metamodel based upon the DOE approach for investigating the overall performance of microchannel heat sinks utilizing a variety of internal fins
, Article International Journal of Heat and Mass Transfer ; Volume 149 , 2020 ; Kazemeini, M ; Rashidi, A ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
In this study, the effects of geometry and operating conditions upon the thermal and hydraulic performance of Finned Microchannel Heat Sink (FMCHS) were investigated. Water and aluminum were considered as fluid and solid for the computational domain (30 mm × 0.8 mm × 0.8 mm). The Microchannel (MC) was supposed to have 0.65 mm height with an aspect ratio of 0.5. CFD analysis was applied for the assessments of four-types of micro-fins (i.e., conical, pyramidal, cylindrical and cubical). In order to evaluate the effects of height, diameter, the spacing of fins and Reynolds number on the overall performance of FMCHS, central composite design at five levels was used to generate design points....
A hybrid fuzzy logic and PID controller for control of nonlinear HVAC systems
, Article System Security and Assurance, Washington, DC, 5 October 2003 through 8 October 2003 ; Volume 3 , 2003 , Pages 2249-2254 ; 08843627 (ISSN) ; Rashidi, F ; Rashidi, M ; Sharif University of Technology
2003
Abstract
Heating, Ventilating and Air Conditioning (HVAC) plant is a multivariable, nonlinear and non minimum phase system, which control of this plant, is very difficult. This paper presents a new approach to control of HVAC system. The proposed method is a hybrid of fuzzy logic and PID controller. Simulation results show that this control strategy is very robust, flexible and alternative performance. To evaluate the usefulness of the proposed method, we compare the response of this method with PID controller. The simulation results show that our method has the better control performance than PID controller
Kinetics Modeling of Platinum Leaching from Reforming Spent Catalysts by iodine/iodide Solution
, M.Sc. Thesis Sharif University of Technology ; Baghalha, Morteza (Supervisor)
Abstract
Platinum is one of the most used catalysts in refining and petrochemical industries. Also, Platinum uses in other industries like automobile catalytic convertor. As respect to importance of Platinum in these industries, growth of its consumption in recent decades and its very high price, recovery of Platinum is essential. Hence, many of various methods including hydro-metallurgy are applied. In despite of these wide spreading experimental investigations, due to low information about the reactions and the nature of reaction products, a few investigations were done on kinetics of Platinum recovery. A new method that used iodine solution to extract Platinum from spent reforming catalysts was...
Anomaly Detection in Software Defined IP Networks
, M.Sc. Thesis Sharif University of Technology ; Akbari, Behzad (Supervisor)
Abstract
With growth in using the Internet and entrance of online stores and internet banks to daily people life, security has become a vital part of this new world. This causes, industrial companies started to produce security devices such as fire walls for protecting network from outside attackers and Intrusion Detection/Prevention Systems (IPS/IDS) for detection of attacks inside network. IPS/IDS causes network overload due to requiring copy of packet or flow information. With introducing Software Defined Networking (SDN) architecture, there is a hope to solve the issue with combining IPS/IDS and SDN features. Therefore, we propose two novel approaches for fast network scanning and SYN Flood...
Improving Write Efficiency in MLC PCM Memory
, M.Sc. Thesis Sharif University of Technology ; Sarbazi-Azad, Hamid (Supervisor)
Abstract
With increasing number of cores and developing sophisticated applications in today’s computer systems, larger main memory capacity is increasingly demanded. Unfortunately, DRAM cannot satisfy the increasing demand for larger main memory capacity due to its power and scalability limits that makes further scaling of DRAM infeasible. Phase Change Memory (PCM) is one of the most promising candidates to be used at main memory level of the memory hierarchy because it is more scalable, denser, and consumes less standby power compared to DRAM. PCM is a new resistive memory which is capable of storing data based on resistance values. The wide resistance range of PCM allows for storing multiple bits...
A Survey on the Effect of Travel Mode Choice on Life Satisfaction by the
Approach of Consonant and Dissonant Travellers
,
M.Sc. Thesis
Sharif University of Technology
;
Kermanshah, Mohammad
(Supervisor)
Abstract
The pursuit of a desirable life and the enhancement of citizens' life satisfaction has long been primary objectives of politicians and urban planners. While various definitions of life satisfaction have been proposed by scholars, it can be conceptualized as a comprehensive, long-term appraisal of one's quality of life, influenced by a range of factors pertaining to their living conditions. Given that mobility is an integral aspect of contemporary societies, transportation and travel mode are widely regarded as key determinants of life satisfaction. It is noteworthy that individual priorities in selecting travel modes are shaped by personal and social characteristics, which may not always...
Design and Fabrication of Inductive High Temperature Superconducting Fault Current Limiter
,
Ph.D. Dissertation
Sharif University of Technology
;
Vakilian, Mehdi
(Supervisor)
;
Fardmanesh, Mehdi
(Supervisor)
Abstract
The continuous rise in electricity demand and the ever growing power generation in different power networks over the world have caused the short circuit level in the power systems to exceed the operational rating of the installed power devices (including cables, circuit breakers and buses). Replacing these devices with new higher rating devices is an expensive solution. From this point of view, utilizing fault current limiters is an economical solution. Superconducting fault current limiters form an efficient category of current limiters. This type is expected to be studied and used widely in future due to their advantages. In this thesis, the first chapter reviews the superconductivity...
Thermal, mechanical and acoustic damping properties of flexible open-cell polyurethane/multi-walled carbon nanotube foams: Effect of surface functionality of nanotubes
, Article Polymer International ; Volume 60, Issue 3 , NOV , 2011 , Pages 475-482 ; 09598103 (ISSN) ; Shojaei, A ; Rashidi, A. M ; Sharif University of Technology
2011
Abstract
This article demonstrates the properties of open-cell flexible polyurethane foams incorporating multi-walled carbon nanotubes. Three different types of highly functionalized nanotubes having carboxyl, hydroxyl and amide functional groups were synthesized. Neat polyurethane foam and three nanocomposite foams filled with 0.1 wt% of treated nanotubes were prepared. It was found that thermal stability, mechanical properties and acoustic damping were improved significantly by incorporation of small amounts of nanotubes. The nanotubes modified with carboxyl groups were found to have much more influence compared to the other two functional groups, possibly due to better interfacial interaction and...