Loading...
Search for: sadat-mirjafari--parisa
0.143 seconds

    The Effect of Travel Time Reliability on Morning Peak Travellers route choice in Large Metropolitan Area

    , M.Sc. Thesis Sharif University of Technology Sadat Mirjafari, Parisa (Author) ; 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 Mirjafari, Morteza (Author) ; 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) Shayegan, J ; 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) Niknam, T ; 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) Torkjazi, M ; 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) Mirjafari, M ; Amini, S ; Ranjbar, A. M ; Sharif University of Technology
    2005

    Experimental Study of Drying and Calcination of Simulated High-Level Waste (HLW)

    , M.Sc. Thesis Sharif University of Technology Farahzadi, Zahra (Author) ; 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... 

    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) Sadat Mozafari, A ; 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... 

    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) Mozafari, B ; 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 Niknam, T ; 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  

    Indoor Noise Pollution Modeling: A Case Study on Resalat Tunnel

    , M.Sc. Thesis Sharif University of Technology Sadat Mortazavi, Mandana (Author) ; 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... 

    Using Information Beyond Text to Generate Language Embedding Vectors

    , M.Sc. Thesis Sharif University of Technology Zeinab Sadat Taghavi (Author) ; 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 Safahieh, Amir Hossein (Author) ; 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 Sadat Alavi, Parisa (Author) ; 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... 

    Analysis of Launch Time in New Product Development With Risk Considerations

    , M.Sc. Thesis Sharif University of Technology Sadat Sharifonnasabi, Zahra (Author) ; Sheikhzadeh, Mehdi (Supervisor)
    Abstract
    The importance of New Product Development (NPD) projects has been realized more and more in recent years. Among different decisions to be made in NPD process, one of the most critical decisions is about the best time to launch new product(s). Due to existence of many internal and external influential factors, determining the optimal launch time is often too complicated and it is quite hard to systematically analyze it. Despite risky nature of NPD, risk considerations in determining the optimal launch time have not been addressed in literature due to the mentioned complexity. In this research, we developed a model that takes in to account risk considerations while systematically determining... 

    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) Hosseini Sohei, M ; 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... 

    Controlling longitudinal safe distance between vehicles

    , Article Promet - Traffic - Traffico ; Volume 21, Issue 5 , 2009 , Pages 303-310 ; 03535320 (ISSN) Sadat Hoseini, S. M ; Fathi, M ; Vaziri, M ; Sharif University of Technology
    2009
    Abstract
    Controlling the safe distances between vehicles on freeways can be used to prevent many accidents. In this research, image-processing techniques have been used to develop an online system that calculates the longitudinal distances between vehicles. This system facilitates controlling safe distances between vehicles without the need for high technology devices. Our approach is real-time and simple, but efficient operations have been used to reduce the image occlusion problem. The main concept of this system is using simple, quick, and effective algorithms for calculating the position of each vehicle in each image. In this way, traffic parameters like speed and distances between vehicles can... 

    A novel structure of dithered nested digital delta sigma modulator with low-complexity low-spur for fractional frequency synthesizers

    , Article COMPEL - The International Journal for Computation and Mathematics in Electrical and Electronic Engineering ; Volume 35, Issue 1 , 2016 , Pages 157-171 ; 03321649 (ISSN) Sadat Noori , S. A ; Farshidi, E ; Sadoughi, S ; Sharif University of Technology
    Emerald Group Publishing Ltd  2016
    Abstract
    Purpose - Digital Delta Sigma Modulator (DDSM) is used widely in electronic circuits including Radars, class-D power amplifiers and fractional frequency synthesizers. The purpose of this paper is to propose an implementation for MASH DDSMs named as Multi Modulus Reduced Complexity (MMRC) architecture. Design/methodology/approach - This architecture will use a very simple pseudorandom Linear Feedback Shift Register (LFSR) dither signal with period N-d to randomize the digital MMRC modulator used for fractional frequency synthesizers. Using error masking methodology, the MMRC modulator can decrease the hardware consumption and increase accuracy of the fractional frequency synthesizer. Rules... 

    Entropy-based video steganalysis of motion vectors

    , Article Entropy ; Volume 20, Issue 4 , 2018 ; 10994300 (ISSN) Sadat, E. S ; Faez, K ; Saffari Pour, M ; Sharif University of Technology
    MDPI AG  2018
    Abstract
    In this paper, a new method is proposed for motion vector steganalysis using the entropy value and its combination with the features of the optimized motion vector. In this method, the entropy of blocks is calculated to determine their texture and the precision of their motion vectors. Then, by using a fuzzy cluster, the blocks are clustered into the blocks with high and low texture, while the membership function of each block to a high texture class indicates the texture of that block. These membership functions are used to weight the effective features that are extracted by reconstructing the motion estimation equations. Characteristics of the results indicate that the use of entropy and... 

    Integration Frameworks for Assimilating Satellite Remote Sensing Observations with Hydrological Model Outputs

    , Ph.D. Dissertation Sharif University of Technology Sadat Soltani, Samira (Author) ; Ataie Ashtiani, Behzad (Supervisor)
    Abstract
    Global climate change and anthropogenic impacts lead to alterations in the water cycle, water resource availability and the frequency and intensity of floods and droughts. As a result, developing effective techniques such as hydrological modeling is essential to monitor and predict water storage changes. However, inaccuracies and uncertainties in different aspects of modeling, due to simplification of meteorological physical processes, data limitations and inaccurate climate forcing data limit the reliability of hydrological models. Assimilation of new observations constrains the dynamics of the model based on uncertainties associated with model and data, which can introduce missing water...