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    Designing Supply Chain and Logistics Network with Multiple Objective Functions under Uncertainty

    , M.Sc. Thesis Sharif University of Technology Safaei, Sepehr (Author) ; Rezapor Niari, Maryam (Supervisor)
    Abstract
    Wheat and flour are vital components of the food supply chain, and disruptions in their supply can have profound economic, social, and political impacts. This study focuses on optimizing the costs of the wheat and flour supply chain, encompassing production, imports, transportation, and shortages, while fostering economic and social development. A two-objective Mixed Integer Linear Programming (MILP) model is developed, integrating uncertainty through a two-stage stochastic programming approach based on scenarios. The augmented epsilon constraint method is utilized to address the bi-objective optimization problem. Key outcomes include identifying optimal locations for silo construction,... 

    Realization Law of Pragnanz and Closure of Gestalt Theory Using Neural Network Modeling and Active Learning Method

    , M.Sc. Thesis Sharif University of Technology Safaei, Negin (Author) ; Bagheri Shouraki, Saeed (Supervisor) ; Mirian Hossinabadi, Maryam (Supervisor)
    Abstract
    Human brain is one the most efficient biological neural network that is capable of performing most complicated tasks in very short time. Visual system as a part of the brain can process the visual records from the environment and perform very useful processes on them. The information provided from visual system processes play important roles in human intelligence. In this thesis we introduce and investigate one of the well-known theories about visual system called gestalt theories. These theories tried to define how a biological neural network can perform such results. Gestalt theorists developed rules of perception to explain their ideas including Law of Pragnanz, Similarity, Closure,... 

    3d Design of a Microfluidic Chip for Anticancer Drugs Screening

    , M.Sc. Thesis Sharif University of Technology Hashemi, Maryam Sadat (Author) ; Mashayekhan, Shohreh (Supervisor) ; Saadatmand, Maryam (Supervisor)
    Abstract
    Nowadays, advanced and inexpensive pre-clinical methods for investigating the effects of anti-cancer drugs are expanding. One of the latest three-dimensional laboratory modeling for evaluating the effects of drugs is the use of tumor-on-chip technology, which actually models the physiological system of the body through three-dimensional scaffolds, multicellular cultures, and shaped vascular systems. In this study, three-dimensional culture of cancer cells was performed in the form of spheroids. A chip of U-shaped microstructures with and without gaps was used to trap cells and form cancer spheroids. We simulated the simultaneous effect of drug and oxygen concentration distribution inside the... 

    Observer-free control of satellite attitude using a single vector measurement

    , Article IEEE Transactions on Aerospace and Electronic Systems ; Vol. 50, issue. 3 , 2014 , pp. 2070-2081 ; ISSN: 00189251 Safaei, F ; Namvar, M ; Sharif University of Technology
    2014
    Abstract
    The existing methods in attitude control of satellites are based on using the estimate of satellite attitude, which is usually generated by using multiple vector measurements. In this paper we propose an output feedback controller that directly uses a single vector measurement and does not use an attitude estimator. The output feedback gain is computed by solving a generalized Riccati differential equation (GRDE). The existence of a solution to the GRDE depends on a uniform controllability condition  

    Output feedback control of satellite attitude using a single vector measurement

    , Article Proceedings of the IEEE Conference on Decision and Control, 10 December 2012 through 13 December 2012, Maui, HI ; 2012 , Pages 490-495 ; 01912216 (ISSN) Safaei, F ; Namvar, M ; Sharif University of Technology
    2012
    Abstract
    The existing methods in attitude control of satellites are based on employing the estimate of satellite attitude which is usually generated by using multiple vector measurements. In this paper we propose an output feedback control law that directly uses a single vector measurement and gyro, and without any need for estimating the satellite attitude. The output feedback gain is computed by solving a generalized Riccati time varying differential equation. We assume the moment-of-inertia matrix of satellite is unknown. The controller guarantees asymptotic convergence of the attitude to its desired value. A realistic simulation is presented where a magnetometer is used to provide the single... 

    3D motion recognition using HMM and nearest neighbor method

    , Article Proceedings of the IASTED International Conference on Signal Processing, Pattern Recognition and Applications, SPPRA 2012 ; 2012 , Pages 17-22 ; 9780889869219 (ISBN) Safaei, A ; Jahed, M ; Sharif University of Technology
    ACTA Press  2012
    Abstract
    Gesture and motion recognition are needed for a variety of applications. The use of human hand motions as a natural interface tool has motivated researchers to conduct research in the modeling, analysis and recognition of various hand movements. In this work, we introduce a 3-D hand motion recognition. We use 3-D landmarked points on finger tips and joints followed by a HMM (Hidden Markov Model) to recognize hand motions. Experimentally, in an effort to evaluate the formation of hand gestures similar to those used in rehabilitation sessions, we studied three hand motions. Using natural hand motion features in an uncontrolled environment, we were able to classify, differentiate and quantify... 

    On the design of graphene oxide nanosheets membranes for water desalination

    , Article Desalination ; Volume 422 , 2017 , Pages 83-90 ; 00119164 (ISSN) Safaei, S ; Tavakoli, R ; Sharif University of Technology
    Elsevier B.V  2017
    Abstract
    According to current researches, graphene oxide (GO) membranes show promising desalination properties due to ease of synthesis, low production cost, and high efficiency. There are several experimental works to study ionic sieving properties of GO membranes. However, it is difficult to characterize atomistic mechanism of water permeation and ion rejection by experimental approaches. On the other hand, there exist a few reports in which the atomistic picture of water permeation across GO membranes is investigated by means of molecular dynamics (MD) simulation. In the present work, in addition to water desalination, the atomic scale mechanism of ion rejection is studied using large scale MD... 

    Quine-McCluskey classification

    , Article 2007 IEEE/ACS International Conference on Computer Systems and Applications, AICCSA 2007, Amman, 13 May 2007 through 16 May 2007 ; 2007 , Pages 404-411 ; 1424410312 (ISBN); 9781424410316 (ISBN) Safaei, J ; Beigy, H ; Sharif University of Technology
    2007
    Abstract
    In this paper the Karnaugh and Quine-McCluskey methods are used for symbolic classification problem, and then these methods are compared with other famous available methods. Because the data in classification problem is very large, some changes should be applied in the original Quine-McCluskey (QMC) algorithm. We proposed a new algorithm that applies the QMC algorithm greedily calling it GQMC. It is surprising that GQMC results are most of the time equal to QMC. GQMC is still very slow classifier and it can be used when the number of attributes of the data is small, and the ratio of training data to the all possible data is high. © 2007 IEEE  

    Entanglement Spectrum of One Dimensional Ising Model in Transverse Field

    , M.Sc. Thesis Sharif University of Technology Safaei, Alireza (Author) ; Langari, Abdollah (Supervisor)
    Abstract
    Entanglement spectrum is the set of eigenvalues of reduced density matrix for a definite state. It contains more information than the entanglement entropy. This spectrum can show entanglement measure, quantum phase transition and topological order in a system. In recent years, the entanglement spectrum for several models has been studied. The entanglement spectrum shows a correspondence to the energy spectrum within some specific regions, which are related to the edge state of the system; It has been verified for the Heisenberg ladder [1] and fractional quantum Hall effect [3]. Moreover, the topological order can be seen in the entanglement spectrum. There exists an acceptable adaption... 

    Automatic Hand and Wrist Motion Tracking and Assessment Using Stereo Vision and Video Processing

    , M.Sc. Thesis Sharif University of Technology Safaei, Amin (Author) ; Jahed, Mehran (Supervisor)
    Abstract
    Gesture and motion evaluation are needed for a variety of applications. The use of human hand motions as a natural interface tool has motivated researchers to conduct research in the modeling, analysis and evaluation of various hand movements. In particular, human-computer intelligent interaction has been a focus of research in vision-based gesture recognition. In this work, we introduce a 3-D hand model evaluation method that offers flexible and elaborate representation of hand motion. We used landmarked points on tips and joints of the fingers and calculated the 3-D coordinates of these points through a stereo vision system followed by an HMM (Hidden Markov Model) to recognize hand... 

    Fault Tolerance in Cloud Storage Systems Using Erasure Codes

    , M.Sc. Thesis Sharif University of Technology Safaei, Bardia (Author) ; Miremadi, Ghassem (Supervisor)
    Abstract
    International Data Company (IDC) has reported, at the end of 2020, the total amount of digital data stored in the entire world will reach 40 thousand Exabytes. The idea of accessing this volume of data, anywhere at any time by exploiting commodity hardware, led into the introduction of cloud storage. The abounded rate and variety of failures in the equipment used in cloud storage systems, placed fault tolerance, at top of the challenges in these systems. HDFS layer in Hadoop has provided cloud with reliable storage. Replication is the conventional method to protect data against failures in HDFS. But the storage overhead is a big deal and therefore designers are tending towards erasure codes.... 

    Attitude Control of Satellite Using a Single Vector Measurement and Gyro

    , Ph.D. Dissertation Sharif University of Technology Safaei, Fatemeh (Author) ; Namvar, Mehrzad (Supervisor)

    Energy-Aware Routing in Internet of Things

    , Ph.D. Dissertation Sharif University of Technology Safaei, Bardia (Author) ; Ejlali, Alireza (Supervisor)
    Abstract
    Internet of Things (IoT) is a communicative infrastructure, which establishes IP-based connections between many smart devices with limited energy supplies. The gathering of such an enormous number of connected devices would impose many challenges, with routing the most important issue. Standardization of the IPv6 Routing Protocol for Low-power and Lossy Networks (RPL) was a major step towards fulfilling the IoT routing requirements. The key element in determining the routing policies and creation of the topology in RPL is the objective function. According to our studies, more than 97% of the consumed energy of a node in wireless networks is due to transceiver activities. On the other hand,... 

    Preparation and characterization of poly-lactic acid based films containing propolis ethanolic extract to be used in dry meat sausage packaging

    , Article Journal of Food Science and Technology ; Volume 57, Issue 4 , 2020 , Pages 1242-1250 Safaei, M ; Roosta Azad, R ; Sharif University of Technology
    Springer  2020
    Abstract
    In this study, active poly lactic acid (PLA) films containing 0, 10, 20 and 40% w/w propolis extract (PE), as active agent, were developed. A high amount of phenolic content (PC) was measured in PE. The antioxidant effect of active PLA films was determined by measuring the PC of sausage slices after 0, 2 and 4 days storage at refrigerator. Results showed that phenolic compounds of PE were released from PLA films in quantities proportional to PE concentration. Disc diffusion test indicated that PE showed an inhibitory effect against Staphylococcus aureus and Pseudomonas aeruginosa bacterial species but was more effective against gram-positive species. PE containing PLA films had antimicrobial... 

    Incremental learning of planning operators in stochastic domains

    , Article 33rd Conference on Current Trends in Theory and Practice of Computer Science, SOFSEM 2007, Harrachov, 20 January 2007 through 26 January 2007 ; Volume 4362 LNCS , 2007 , Pages 644-655 ; 03029743 (ISSN); 9783540695066 (ISBN) Safaei, J ; Ghassem Sani, G ; Sharif University of Technology
    Springer Verlag  2007
    Abstract
    In this work we assume that there is an agent in an unknown environment (domain). This agent has some predefined actions and it can perceive its current state in the environment completely. The mission of this agent is to fulfill the tasks (goals) that are often assigned to it as fast as it can. Acting has lots of cost, and usually planning and simulating the environment can reduce this cost. In this paper we address a new approach for incremental induction of probabilistic planning operators, from this environment while the agent tries to reach to its current goals. It should be noted that there have been some works related to incremental induction of deterministic planning operators and... 

    Bioactive Packaging Study to Improve the Quality of Food Products

    , M.Sc. Thesis Sharif University of Technology Safaei, Maryam (Author) ; Roostaazad, Reza (Supervisor)
    Abstract
    One of the most important concerns in food industry is decreasing the contamination of food and increasing their shelf life. Antimicrobial/antioxidant packaging, an active packaging concept, can be considered an extremely challenging technology that could have a significant impact on shelf-life extension and food safety of meat and meat products. Due to harmfulness of chemical preservatives, their use has been limited and therefore natural antimicrobial/antioxidant agents have become more popular. Propolis is a natural resinous substance, with a high polyphenol content, produced by honeybees and characterized by antimicrobial, anti-inflammatory and antioxidant properties, which make it... 

    Molecular Dynamics Simulation of Water Nanofiltration by Graphene Oxide Membranes

    , M.Sc. Thesis Sharif University of Technology Safaei, Sina (Author) ; Tavakoli, Rohollah (Supervisor)
    Abstract
    According to current researches, graphene oxide (GO) membranes show promising desalination properties due to ease of synthesis, low production cost, and high efficiency. There are several experimental works to study ionic sieving properties of GO membranes. However, it is difficult to characterize atomistic mechanism of water permeation and ion rejection by experimental approaches. On the other hand, there exist a few reports in which the atomistic picture of water permeation across GO membranes is investigated by means of molecular dynamics (MD) simulation. In the present work, in addition to water desalination, the atomic scale mechanism of ion rejection is studied using large scale MD... 

    Model Checking of Stochastic Activity Networks

    , M.Sc. Thesis Sharif University of Technology Maryam Bagheri (Author) ; Movaghar, Ali (Supervisor)
    Abstract
    Modeling and performance evaluation of the real time distributed systems is a significant problem. Stochastic activity network is one of the high level models used for this purpose. This network is an extension of generalized stochastic Petri net which is more powerful and flexible than other Petri net extensions. Checking the satisfiability of properties such as performance, dependability and user's expected properties is considerable in these models. Thus, using the approaches and generating modeling and model checking tools with the mentioned purpose is attractive. A model checker automatically checks the correctness of the system behaviors as properties against the model by getting the... 

    Robust Estimation and Control of a Planet Lander

    , M.Sc. Thesis Sharif University of Technology Ahmadvand, Reza (Author) ; Kiani, Maryam (Supervisor)
    Abstract
    This study has focused on the important problem of landing on a planet as an important current and future space mission. In this regard, dynamics modeling and integrated state estimation and control problems have been investigated in different views. To this aim, first a novel concurrent representation for translational and rotational kinematics has been developed based on the extension of modified Rodrigues parameters to dual space. This parameter set, called dual modified Rodrigues parameters (DMRP), is then utilized to establish an integrated roto-translational dynamic. The proposed DMRP-based kinematics and dynamics have been verified via comparison to traditional methods of... 

    Optimal Energy Trading in a Smart Grid Based on Extremum-seeking Algorithm

    , M.Sc. Thesis Sharif University of Technology Asgari, Houman (Author) ; Babazadeh, Maryam (Supervisor)
    Abstract
    Prevalent deployment of Distributed Energy Resources(DERs) in the demand side of electrical energy grids has several advantages such as greenhouse gases emission reduction, mitigation of power losses in the distribution grids and abatement of the dependency on the wholesale generation companies. At the same time, it paves the way for the advent of local interactive energy trading frameworks. In the following thesis, a distributed data-driven algorithm is developed for market-clearing in a community-based local energy market. The social welfare maximization is considered as the objective of the energy trading. The production and demand of electricity are the decision variables of sellers and...