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daghighi-masuleh--majid
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Total 211 records
Sliding Contact Problem of a Round Wedge with a FGM Coated Substrate
, M.Sc. Thesis Sharif University of Technology ; Adibnazari, Saeed (Supervisor)
Abstract
In this research, sliding contact problem of a rounded apex wedge with a FG coated substrate is investigated. The structure includes two components. The first is the FG coating and then, the homogeneous substrate which is connected to the FG coating. Usually, it is considered that the homogeneous substrate is a metal and properties at the connection are metallic. Then, properties varies gradually through the thickness of the FG coating, so, the material at the surface of the structure is a ceramic. It is assumed that, properties varies exponentially and continuously through the FG coating and the poisson’s ratio is constant. Beside, it is supposed that the conditions of coulomb friction...
Data-driven Nexus Analysis and Optimization of a Complex Thermo-gasdynamic Energy System and Implementation on an Old National Thermal Power plant in Operational Conditions
, M.Sc. Thesis Sharif University of Technology ; Mazaheri, Karim (Supervisor)
Abstract
The performance of the power plant decreases during its lifetime and deviates from its design and initial operation conditions; Maintenance issues, variety of operational patterns, market limitations and financial goals have been caused this situation. Knowing the appropriate actions and finding the optimal operation conditions of the power plant can support the system to restore its initial operational performance and bring it closer to its design condition. In this research, with historical data helps of a steam thermal power plant in Kermanshah, unsupervised machine learning techniques have been used to identify operational patterns, which lead to the identification of optimal operating...
Scheduling for data centers with multi-level data locality
, Article 2017 25th Iranian Conference on Electrical Engineering, ICEE 2017, 2 May 2017 through 4 May 2017 ; 2017 , Pages 927-936 ; 9781509059638 (ISBN) ; Kavousi, M ; Sharif University of Technology
2017
Abstract
One of the challenging problems in real-time data-parallel processing applications is to schedule tasks to different servers aiming to increase data locality for higher efficiency or lower delay, and at the same time, doing load balancing to stabilize the system of server-queues. We target this problem, and discuss efficient real-time task scheduling algorithms aimed not only to stabilize the system when the arrival rate is in the capacity region (i.e. throughput optimality condition), but also to minimize the mean delay of all tasks in heavy traffic regime when the arrival rate approaches the capacity boundary (i.e. heavy-traffic optimality condition). In this paper, we point out the data...
Adaptive random puncturing based secure block turbo coding
, Article 2010 5th International Symposium on Telecommunications, IST 2010, 4 December 2010 through 6 December 2010 ; December , 2010 , Pages 216-220 ; 9781424481835 (ISBN) ; Payandeh, A ; Aref, M. R ; Sharif University of Technology
2010
Abstract
Reliability and security are two important subjects in modern digital communications. A secure channel coding scheme provides both of reliability and security in one process to combat problems in an unreliable and insecure channel. In this paper, a secure block turbo coding scheme will be proposed and analyzed. Security and reliability are based on pseudo-random puncturing. Simulation results show that this scheme has superior performance and high security
The effect of nano-size additives on the electrical conductivity of matrix suspension and properties of self-flowing low-cement high alumina refractory castables
, Article Ceramics International ; Volume 36, Issue 4 , 2010 , Pages 1411-1416 ; 02728842 (ISSN) ; Sagaeian, A ; Daghighi, A ; Nemati, Z. A ; Sharif University of Technology
2010
Abstract
Influence of two nano-size additives oSubject:A. Suspensions. Subject:C. Electrical conductivity. Subject:Castable. Subject:E. Refractories. Subject:Castables. Subject:Electrical conductivity. Subject:Electrical property. Subject:High alumina. Subject:matrix. Subject:Mechanical strength. Subject:Nano-size. Subject:Polycarboxylate ethers. Subject:Refractory castables. Subject:Working time. Subject:Alumina. Subject:Cement additives. Subject:Electric conductivity. Subject:Ethers. Subject:Suspensions (fluids) Subject:Refractory materials. n electrical properties of suspension matrix of self-flowing low-cement high alumina refractory castable is investigated. For this purpose, castament FS 10 and...
A moving-mesh finite-volume method to solve free-surface seepage problem in arbitrary geometries
, Article International Journal for Numerical and Analytical Methods in Geomechanics ; Volume 31, Issue 14 , 2007 , Pages 1609-1629 ; 03639061 (ISSN) ; Torabi, S. O ; Saadat, M ; Daghighi, Y ; Jarrahbashi, D ; Sharif University of Technology
2007
Abstract
The main objective of this work is to develop a novel moving-mesh finite-volume method capable of solving the seepage problem in domains with arbitrary geometries. One major difficulty in analysing the seepage problem is the position of phreatic boundary which is unknown at the beginning of solution. In the current algorithm, we first choose an arbitrary solution domain with a hypothetical phreatic boundary and distribute the finite volumes therein. Then, we derive the conservative statement on a curvilinear co-ordinate system for each cell and implement the known boundary conditions all over the solution domain. Defining a consistency factor, the inconsistency between the hypothesis...
The Effects of Intentional Process Models on Goal Modeling and Process Conformance Checking
, M.Sc. Thesis Sharif University of Technology ; Rafiei, Majid (Supervisor) ; Khedmati, Majid (Supervisor)
Abstract
In recent years, requirement engineering and goal modeling have gained more attention among different organisations. Therefore, different methods have been designed to discover stakeholders’ requirements and translate them into process and organizational goals. Various goal models have been introduced to represent these goals and their relations towards each other. Still, these methods are manual representations of different process scenarios and do not relate to the actual behavior. In 2014, Map Miner Method (MMM) was introduced to discover intentional process models from event logs. MMM uses Hidden Markov Model (HMM) as a means to represent the process as a map model of strategies and...
A Trajectory Recommendation System for Efficient Finding of Passengers
, M.Sc. Thesis Sharif University of Technology ; Khedmati, Majid (Supervisor) ; Rafiee, Majid (Supervisor)
Abstract
Recommending routes to city taxis in order to improve their performance in finding passengers can reduce traffic, pollution and waiting time for passengers, as well as this, increasing the efficiency of taxis can increase their income. In this study, by analyzing trajectory data obtained from 536 taxis in San Francisco over a period of one month, we generated networks of cells, each of which has time-dependent characteristics such as the probability of finding a passenger, the capacity of each cell, or the amount of demand exists is in the cell and the average speed of passing through that cell. also, the connections between these cells in order to make more use of the experiences of taxi...
Extracting Mental Models Through Textual Analysis
, M.Sc. Thesis Sharif University of Technology ; Khosravizadeh, Parvaneh (Supervisor) ; Vazirnezhad, Bahram (Co-Advisor)
Abstract
Mental models are a reflection of the individuals’ cognitive structure. In fact, these models are the conceptual frameworks that people form based on their experiences and knowledge. These models gives the individuals the ability to predict the results of an action and interpret their surroundings. In this cognitive-linguistic study, mental models are defined as concepts and the relationships between them in a particular context. Considering this definition of mental models, we could extract the mental models of two American presidents of opposing parties, Barack Obama and George W. Bush, from their speech transcriptions during their presidential periods and classify their concepts in to...
Improving Artificial Neural Network Predictive Performance Using Panel Data
, M.Sc. Thesis Sharif University of Technology ; Khedmati, Majid (Supervisor) ; Rafiee, Majid (Supervisor)
Abstract
The purpose of the present study is to develop neural network estimation method for hybrid or panel data which have a combination of two cross-sectional and time series structures and because of the features of both structures, their use in different sciences offers many advantages; and the analytical methods for this data structure are also different from other one-dimensional structures, so different and specific regression models are presented for this data structure. However, in the artificial neural network method, modeling the development for this data structure is neglected, so in the present study, using the concepts of panel regression methods and their application to the...
Impelementation of Numerical Method For Hydrodynamic Behavior for Salvage of a Sunken Ship
, M.Sc. Thesis Sharif University of Technology ; Abbaspour, Majid (Supervisor)
Abstract
One of the utmost important factors during salvage operation of drowned ships is raising velocity. Uncontrolled raise is a dynamic phenomenon which can lead to the sudden tensions, collapse in airbags or ships. Studing this issue helps the engineers which kinds of problems are more important during salvage operations. This study focus on modeling and analysis of raising movment of the ship with FLOW-3D and ABAQUS software.
In FLOW-3D environment, hydrodynamic analysis of rising movment of drowned ship has been done. We should mention that applied forces and velocities and other parameters from the FLOW-3D output should be passed IMCA Criteria to avoid uncontrollable raise. In ABAQUS...
In FLOW-3D environment, hydrodynamic analysis of rising movment of drowned ship has been done. We should mention that applied forces and velocities and other parameters from the FLOW-3D output should be passed IMCA Criteria to avoid uncontrollable raise. In ABAQUS...
The Application of Profile Monitoring in Healthcare for Disease Monitoring- case Study
, M.Sc. Thesis Sharif University of Technology ; Rafiee, Majid (Supervisor)
Abstract
Profile Monitoring is a new research topics in the field of statistical process control. In many applications of statistical quality control, sometimes quality of a process or product described by a relationship between a response variable and one or more independent variables.The researchers call this relationship profile. The study seeks to demonstrate that monitoring profiles In addition, the industry can be effective in medical field and improves control of the patient's condition by a doctor. Profiles are usually modeled with a linear regression equation, non-linear or polynomial. finally, the results of this study, using actual data, models and methods to predict and control...
Experimental Study on Extracting Clean Energy from Vortex Induced Vibration
, M.Sc. Thesis Sharif University of Technology ; Abbaspour, Majid (Supervisor)
Abstract
Two experimental models were designed and tested to extract energy from vortex induced vibrations of a elastically mounted one degree of freedom rigid cylinder in the Reynolds range of 120000 < Re <220000. In the first model the amplitude and frequency of the movement was measured then a second model was designed to be tested in the Emam Hossein marine laboratory. The model was designed in a way that many of its properties like mass ratio, spring constant and damping coefficient were able to be altered. In this study the vortex induced vibration of an elastically mounted cylinder was scrutinized in high Reynolds and very low mass ratios for the first time and an amplitude ratio of 2.49 were...
Optimization of Radiotherapy Plan under Uncertainty
, M.Sc. Thesis Sharif University of Technology ; Rafiee, Majid (Supervisor)
Abstract
As a method of cancer treatment or improvement of cancer-related complications, external radiation therapy is prescribed by physicians, in case of detection of a tumor in a region of patient’s body. Over time, various techniques have been developed for external beam radiation therapy. Among which, Intensity Modulated Radiation Therapy (IMRT), due to its ability to adjust the intensity of radiation beams, has a higher capacity to generate appropriate dose distribution based on tumor size and volume and it is one of the most widely used techniques in cancer treatment centers.The core process in treatment planning is using appropriate computer algorithms which results in posing enough damage to...
Selection of Resilience Supply Portfolio with Uncertainties
, M.Sc. Thesis Sharif University of Technology ; Rafie, Majid (Supervisor)
Abstract
Supplier selection and order quantity allocation problem is one of the most complex making decision problems comes into account. In the past, supplier selection done based on criteria such as price, quality and delivery time. Today's supply chains with the aim of expanding business activities and improving their performances, Follow process such as outsourcing, product development, and selection of multi-supplier strategies. This conditions will bring opportunities and threats for supply chains. One of the possible risks to supply chains are disruption risks and disruption has been a great concern in the past decade and disruption of suppliers are one of the new topics that have recently...
Transplant Process Optimization in Kidney Donation Problem
, M.Sc. Thesis Sharif University of Technology ; Rafiee, Majid (Supervisor)
Abstract
At the present, End-stage renal disease(ESRD) is the ninth-leading cause of death in the USA.according methods of medical treatment for End-stage renal disease (ESRD), transplantation is the most viable renal replacement therapy for ESRD patients, there is a disparity between the demand for kidneys for transplantion and the supply. Incompatible inblood-type and antigen matching between patient-donor pairs is cause of shortage in disparity between the demand and the supply.paired kidney exchange of kidney among incompatible patient-donor pairs.PKE can be solve many difficulties in matching patient with incompatible donors. Kidney transplant surgeries in PKE must take place simultaneously...
Optimal Design of Hydrofoil for Marine Current Turbine
, M.Sc. Thesis Sharif University of Technology ; Abbaspour, Majid (Supervisor)
Abstract
Marine current power has been utilized in recent years as one of the most foreseeable renewable energy sources. In this study a multi-objective hydrofoil optimal design is carried out for use in marine current turbine in order to improve hydrodynamic performance due to low speed current in Qeshm channel. A particle swarm optimization code using FORTRAN is developed and coupled with XFoil software as flow solver that is based on panel method. B-spline curve is used to parameterize the hydrofoil shape and the coordinates values of the control points are designated to act as optimization parameters. Validity of flow solver examined by comparison made between computed data against experimental...
Proposing a Solution Algorithm for Operating Room Scheduling Problem Using Open Scheduling and Elective Patient Strategy
, M.Sc. Thesis Sharif University of Technology ; Rafiee, Majid (Supervisor)
Abstract
Operating rooms have always been the most expensive and also the most profitable section in hospitals which include approximately one third of cost and two third of income. The management always wants to decrease the cost of hospitals. On the other hand, usually this goal stands against other goals such as patient’s satisfaction. So the manager should make a balance between these goals. In this research, we will propose an integer programming model for operating room scheduling problem without uncertainty for elective patients. In order to make the model more realistic, we want to make connection between operating room theatre and intensive care units. Also, we will consider desirable...
Fluence Map Optimization in IMRT Planning under Uncertainty
, M.Sc. Thesis Sharif University of Technology ; Rafiee, Majid (Supervisor)
Abstract
Cancer is one of the main causes of death among all people around the world. This shows that more and more attention should be paid to cure cancer. One of the most common cancer treatments is radiation therapy. Among all radiation therapy treatments, Intensity-Modulated Radiation Therapy is a very effective and flexible ways to treat cancer. There are numerous mathematical problems to find the perfect treatment plan. One of these mathematical problems is Fluence Map Optimization in which we try to find the best dose intensity for each tumor and surrounding organs. The main purpose in this problem is to minimize the number of cancerous cells which are being destroyed while minimizing the...
Development of a Model to Investigate Energy Production Potential from Sea Applying GIS Technique
, M.Sc. Thesis Sharif University of Technology ; Abbaspour, Majid (Supervisor)
Abstract
The growing requirements for renewable energy production lead to the development of a new series of systems, including wave and tidal energy conversion systems. Due to their sensitivity and the impact of the aggressive marine environment, the selection of the most adequate location for these systems is a major and very important task. Several factors, such as technological limitations, environmental conditions, administrative and logistic conditions, have to be taken into account in order to support the decision for best location. The aim of the present study is to provide an Atlas of IRAN Offshore Renewable Energy Resources (hereafter called ‘the Atlas’) to map out wave and tidal resources...