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The Effect of Travel Time Reliability on Morning Peak Travellers route choice in Large Metropolitan Area
, M.Sc. Thesis Sharif University of Technology ; Poorzahedy, Hossein (Supervisor)
Abstract
Data collected from street networks show that travel time in urban street networks is a stochastic variable, whose range of variation increases with the congestion level. Work and school trips comprise the major part of morning peak volumes, whose common characteristic is that they need to be made on time. For this reason, these travelers are pessimistic in their route choice, and try to choose routes which are more reliable. Travel time standard deviation is one of the common measures for estimating travel time reliability that is related to properties of day-to-day travel time distribution on a particular route. Based on the empirical data collected from Tehran street network, this paper...
Conjunctive Use of Surface and Ground Water Resources in Subject to Minimize the Storage and Pompage Costs in Drought Condition
, M.Sc. Thesis Sharif University of Technology ; Abrishamchi, Ahmad (Supervisor)
Abstract
Using a combination of groundwater and surface water, is defined as each project planned by combining these two sources which, in most cases, will achieve greater benefits than the non-integrated. The benefit is a set of privileges that technically, economically and environmentally justify the project. One of the prevalent and effective problems of fertile and flat plains of Khuzestan province, especially the Evan plain, is lack of proper drainage of agricultural land downstream of dams and irrigation networks which are covered by. In this plain also, according to statistics from Piezometers, the groundwater level is rising. At the first, the aim of this study is to study the current...
The effect of influent COD and upward flow velocity on the behaviour of sulphate-reducing bacteria
, Article Process Biochemistry ; Volume 40, Issue 7 , 2005 , Pages 2305-2310 ; 13595113 (ISSN) ; Ghavipanjeh, F ; Mirjafari, P ; Sharif University of Technology
2005
Abstract
The effect of up velocity and influent COD concentration on the activity of sulphate-reducing bacteria (SRB) in UASB reactors is discussed. To study these effects, four UASB reactors were built and utilized in parallel. Examinations were carried out in two different concentrations of molasses (500 mg COD/l and 1000 mg COD/l) and four different upward flow velocities. It was observed that at velocities greater than 1 m/h, SRB bacteria were easily washed out from the reactors due to lower density and lack of ability to form dense and firm granules. It was found that in low-strength wastewaters with a COD to sulphate ratio of 2, an upward velocity in the range of 1.5-2.5 m/h could be...
Reactive power pricing in deregulated environments using novel search methods
, Article Proceedings of 2004 International Conference on Machine Learning and Cybernetics, Shanghai, 26 August 2004 through 29 August 2004 ; Volume 7 , 2004 , Pages 4234-4239 ; 0780384032 (ISBN) ; Arabian, H ; Mirjafari, M ; Sharif University of Technology
2004
Abstract
In this paper two novel search methods for solving optimal power flow (OPF) have been presented and compared. Electricity is undergoing a restructuring process, moving from integrated environment towards deregulation and reduced regulation all around the world. Electrical energy markets are going to be created as a consequence of this process. In order to meet technical issues, system operator would need to apply some ancillary services. Reactive power is one of the most important ancillary services, which should be injected to power network in order to decrease the total loss and control the voltage profile. The main goal of this study is to present a method based on a Locational Marginal...
Reliability-based network flow estimation with day-to-day variation: A model validation on real large-scale urban networks
, Article Journal of Intelligent Transportation Systems: Technology, Planning, and Operations ; 2017 , Pages 1-23 ; 15472450 (ISSN) ; Sadat Mirjafari, P ; Poorzahedy, H ; Sharif University of Technology
2017
Abstract
Day-to-day variation in the travel times of congested urban transportation networks is a frustrating phenomenon to the users of these networks. These users look pessimistically at the path travel times, and learn to spend additional time to safeguard against serious penalties that await late arrivals at the destinations. These additional expenses are charges similar to the tolls in system equilibrium flow problem, but may not be collected. With this conjecture, the user equilibrium (UE) formulation of congested network flow problem would lack some necessary factors in addressing appropriate path choices. This study, following a previous work proposing pessimistic UE (PUE) flow, aims to show...
Electromagnetic design optimization of a disk permanent magnet microgenerator
, Article Eighteenth International Conference and Exhibition on Electricity Distribution, CIRED 2005, Technical Reports - Session 1: Network Components, Turin, 6 June 2005 through 9 June 2005 ; Volume 4, Issue 2005-11034 , 2005 , Pages 23-27 ; 05379989 (ISSN) ; Amini, S ; Ranjbar, A. M ; Sharif University of Technology
2005
Particle swarm optimization method for optimal reactive power procurement considering voltage stability
, Article Scientia Iranica ; Volume 14, Issue 6 , 2007 , Pages 534-545 ; 10263098 (ISSN) ; Amraee, T ; Ranjbar, A. M ; Mirjafari, M ; Sharif University of Technology
Sharif University of Technology
2007
Abstract
This paper presents and utilizes an Improved Particle Swarm Optimization algorithm (IPSO) for reactive power management in restructured power systems. Reactive power procurement is modeled as a Security Constraint Optimal Power Flow (SCOPF), which incorporates a voltage stability problem. This is a major concern in power system control and operation. The model attempts to minimize the cost of reactive power procurement and energy losses as a main objective, while the technical criteria and voltage stability margin, especially, are treated as soft constraints. From a mathematical point of view, the reactive power market can be expressed as a nonlinear non-convex optimization problem with...
Optimal reactive power planning in harmonic distored power system using genetic algorithm
, Article IEEE TENCON 2004 - 2004 IEEE Region 10 Conference: Analog and Digital Techniques in Electrical Engineering, Chiang Mai, 21 November 2004 through 24 November 2004 ; Volume C , 2004 , Pages C347-C350 ; Ranjbar, A .M ; Arabian, H ; Mirjafari, M ; Sharif University of Technology
2004
Abstract
A continuous growth in nonlinear loads may cause an increment in harmonic distortion and some other important problems in power systems so considering power quality effects in optimal reactive power planning has become more crucial than before. In this paper, optimal reactive power planning based on voltage profile deviation and voltage THD decrement is studied. The planning problem is studied using reactive power injection in each bus bar and genetic algorithm is also used for solving optimization problem. Obtained results for 5-bus and 30-bus IEEE standard networks are also presented. ©2004IEEE
Cluster-based adaptive SVM: a latent subdomains discovery method for domain adaptation problems
, Article Computer Vision and Image Understanding ; Volume 162 , 2017 , Pages 116-134 ; 10773142 (ISSN) ; Jamzad, M ; Sharif University of Technology
2017
Abstract
Machine learning algorithms often suffer from good generalization in testing domains especially when the training (source) and test (target) domains do not have similar distributions. To address this problem, several domain adaptation techniques have been proposed to improve the performance of the learning algorithms when they face accuracy degradation caused by the domain shift problem. In this paper, we focus on the non-homogeneous distributed target domains and propose a new latent subdomain discovery model to divide the target domain into subdomains while adapting them. It is expected that applying adaptation on subdomains increase the rate of detection in comparing with the situation...
Experimental Study of Drying and Calcination of Simulated High-Level Waste (HLW)
, M.Sc. Thesis Sharif University of Technology ; Samadfam, Mohammad (Supervisor) ; Zahakifar, Fazel (Supervisor) ; Zaheri, Parisa (Co-Supervisor)
Abstract
One of the novel methods of stabilization of nuclear waste is the use of vitrification technology. In order to stabilize high level wastes (HLLW) in glass, it is required that the elements are in their oxide form. Therefore, it is necessary to evaporate the waste and turn it into a solid form so that the elements can be converted into oxide form in the calcination furnace. Hence, one of the challenges of stabilization is the optimization of evaporation and calcination conditions. In this research, the parameters affecting evaporation were first investigated. Using laboratory measurements of application: temperature (110 to 180 °C), presence of nitric acid (0.5 to 4 mol/L), ratio of zirconium...
The Study of Effective Parameters on Thorium Extraction by Cyanex 272 in an Emulsion Liquid Membrane System
, M.Sc. Thesis Sharif University of Technology ; Samadfam, Mohammad (Supervisor) ; Zaheri, Parisa (Supervisor) ; Zahakifar, Fazel (Co-Supervisor)
Abstract
This study used the emulsion liquid membrane method to investigate the extraction and separation of thorium from nitrate solution. According to the results obtained from the studies, Cyanex 272 was a suitable option for selectively extracting thorium. For simultaneous extraction and stripping of thorium from dilute aqueous solutions, an emulsion liquid membrane system consisting of Cyanex 272 as an extractant, Span 80 as a surfactant and sulfuric acid solution as a receiving phase (internal phase) was used. Emulsion liquid membrane method has high mass transfer flux due to high surface to volume ratio, which causes high extraction efficiency and fast transfer of thorium ions from its low...
Indoor Noise Pollution Modeling: A Case Study on Resalat Tunnel
, M.Sc. Thesis Sharif University of Technology ; Vaziri, Manouchehr (Supervisor)
Abstract
Noise or noise pollution, is defined as an unwanted sound, produced mostly by motor vehicles in urban areas. If the noise exceeds its limit, adverse effects on users and citizens are expected. Thus the assessment of the noise level and its comparison with allowable values is mandatory. Traffic induced noise depends upon different factors such as traffic, weather, and, sound barriers. Noise pollution study has a long history all over the world. Many studies, mostly representing the outdoor noise pollution models, have been done in recent years. This paper presents an assessment of traffic-induced noise in a heavily traveled tunnel, locally referred to as Resalat tunnel, which is located in...
Design and Implementation of a FlexRay Transceiver
, M.Sc. Thesis Sharif University of Technology ; Atarodi, Mojtaba (Supervisor)
Abstract
With the advancement of automotive industry, the number of electronic systems that need to communicate with each other has increased. An effective strategy to meet these growing demands is using bus-based protocols, which can establish safe communication among numerous nodes with reasonable cost, weight, and space requirements. The objective of this thesis is the design and implementation of a transceiver based on the FlexRay protocol. The significance of this protocol lies in its ability to provide higher data transmission rates compared to other protocols like CAN and LIN, and its role as the foundational communication medium among various domains in modern vehicle architectures. In this...
Using Information Beyond Text to Generate Language Embedding Vectors
, M.Sc. Thesis Sharif University of Technology ; Sameti, Hossein (Supervisor)
Abstract
In this thesis, we introduce a novel Artificial Intelligence (AI) system inspired by the philosophical and psychoanalytical concept of imagination as a ``Re-construction of Experiences". Our AI system is equipped with an imagination-inspired module that bridges the gap between textual inputs and other modalities, enriching the derived information based on previously learned experiences. A unique feature of our system is its ability to formulate independent perceptions of inputs. This leads to unique interpretations of a concept that may differ from human interpretations but are equally valid, a phenomenon we term as ``Interpretable Misunderstanding". We employ large-scale models,...
Fabrication Patient-Specific Drill Guide Templates for Cervical Pedicle Screw Placement
, M.Sc. Thesis Sharif University of Technology ; Arjmand, Navid (Supervisor) ; Parnianpour, Mohammad (Supervisor) ; Azimi, Parisa (Co-Supervisor)
Abstract
One of the most common spinal surgeries involves spinal fusion or vertebral fixation, which is used to treat various conditions such as intervertebral disc disease, scoliosis (lateral deviation of the spinal column), fractures, infections, or the presence of tumors in the spinal column. In this surgical procedure, the use of pedicle screws and titanium rods prevents motion and friction between two vertebrae. Screws may enter the vertebrae in the wrong position and angle, causing bone weakening, rupture of nerve roots or blood vessels, weakness or lack of sensation in some parts of the body, spinal cord injury, and in severe cases, paralysis of the patient. For this reason, fusion surgery is...
Deformation and Annealing Behavior of an Austenitic Stainless Steel
, M.Sc. Thesis Sharif University of Technology ; Serajzadeh, Siamak (Supervisor)
Abstract
In this research, non-isothermal annealing process at temperatures ranging between 400°C to 830 °C was investigated in warm and cold-rolled austenitic stainless steel 304L. First, the wide variety of austenitic to martensitic structure was produced by the multi-pass rolling process at room temperature -8 °C, 200 °C, and 280°C. The n exponent in Olson-Cohen equation was governed 2.83 after non-linear curve fitting to assess the fraction of deformation-induced martensite as a function of strain. Afterward, Abaqus/Explicit method was utilized to achieve the stored energy and plastic strains distribution through the thickness. Then, Cellular automata and Galerkin-finite element models were...
Optimal reactive power dispatch in a joint active / reactive market model
, Article 2006 International Conference on Power System Technology, POWERCON2006, Chongqing, 22 October 2006 through 26 October 2006 ; 2006 ; 1424401119 (ISBN); 9781424401116 (ISBN) ; Amraee, T ; Ranjbar, A. M ; Mirjafari, M ; Shirani, A. R ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2006
Abstract
The participants in auction-based electricity markets need to take part in a competition way which operates based on the concept of supply and demand theory to buy or sell the electricity. However, to have a feasible market solution, reactive power services are necessary to support the transmission of power from generation to end-users. This paper presents a methodology for optimal reactive power procurement, consistent with the auction-based electricity market mechanism. The proposed reactive power market is run in subsequence of the primary electricity market, allowing active power modification in light of available transmission capacity and reactive power resources. The IEEE 30-bus test...
Optimal reactive power dispatch in a joint active / reactive market model
, Article 2006 IEEE PES Transmission and Distribution Conference and Exposition: Latin America, TDC'06, Caracas, 15 August 2006 through 18 August 2006 ; 2006 ; 1424402883 (ISBN); 9781424402885 (ISBN) ; Amraee, T ; Ranjbar, A. M ; Mirjafari, M ; Shirani, A. R ; Sharif University of Technology
2006
Abstract
The participants in auction-based electricity markets need to take part in a competition way, which operates, based on the concept of supply and demand theory to buy or sell the electricity. However, to have a feasible market solution, reactive power services are necessary to support the transmission of power from generation to end-users. This paper presents a methodology for optimal reactive power procurement, consistent with the auction-based electricity market mechanism. The proposed reactive power market is run in subsequence of the primary electricity market, allowing active power modification in light of available transmission capacity and reactive power resources. The IEEE 30-bus test...
A hybrid of particle swarm and ant colony optimization algorithms for reactive power market simulation
, Article Journal of Intelligent and Fuzzy Systems ; Volume 17, Issue 6 , 2006 , Pages 557-574 ; 10641246 (ISSN) ; Ranjbar, A. M ; Amraee, T ; Mirjafari, M ; Shirani, A. R ; Sharif University of Technology
2006
Abstract
In Particle Swarm Optimization (PSO) algorithm, although taking an active role to guide particles moving toward optimal solution, the most-fit candidate does not have a guide itself and only moves along its velocity vector in every iteration. This may yield a noticeable number of agents converge into local optima if the guide (i.e. the most fit candidate) agent cannot explore the best solution. In this paper, an attempt is made to get the advantage of the Ant Colony Optimization (ACO) methodology to assist the PSO algorithm for choosing a proper guide for each particle. This will strengthen the PSO abilities for not getting involved in local optima. As a result, we present a promising new...
Utilizing network coding for file dessimination in peer-to-peer systems
, Article 3rd International Conference on New Technologies, Mobility and Security, NTMS 2009, 20 December 2009 through 23 December 2009, Cairo ; 2009 ; 9781424462735 (ISBN) ; Movaghar, A ; Sadat Bathaee, N ; Sharif University of Technology
2009
Abstract
Network coding was first introduced in information theory for increasing the multicast rate in the networks with directed links. We can model many of the content distribution networks and overlay networks with such a network. Therefore, the solutions introduced in information theory can be used in these networks. In this paper, we analyze using of network coding in uncoordinated cooperative content distribution systems. Reaching the optimum performance in an uncoordinated system needs blocks of the system to be "equally important". In that case, we can retrieve the whole data without need of central controller or complex algorithms. In part of this paper, we exactly define the concept of...