Search for: termination
0.009 seconds
Total 97 records

    Study, Analysis & Optimizing The Process Of Approval, Design & Implementation Of Projects In The Iranian Oil Terminal Company(IOTC)

    , M.Sc. Thesis Sharif University of Technology Moosavi, Saeed (Author) ; Mostafavi, Mostafa (Supervisor)
    Since the Iranian oil terminals company(I.O.T.C.) has been the main and strategic gateway of exporting petroleum in the country and plays an important role in the optimum continuity of national, regional and international energy supply chain and also conducting the needed projects whit a desirable quality and minimum time and cost has a prominent influence on steady continuity of manufacturing, importing and exporting of petroleum and gas production. The main purpose of doing this thesis is diagnosing the process of approval, design and implementation of projects in the I.O.T.C., Thus, whit regarding to the modern needs of implementing projects and the necessity of reviewing the structure... 

    Introducing a Simulation-Based Model to Improve the Design and Layout of Workstations Inside Airport Terminals in Iran

    , M.Sc. Thesis Sharif University of Technology Amini Esfidvajani, Amin Mohammad (Author) ; Alvanchi, Amin (Supervisor)
    The airport terminal is difficult to plan and design due to the different components and the intricate complexity of its parts. At the airport terminal, we face a queue system which simulation is always a good way to analyze. In addition, computer simulation using modern softwares with the capability to model different types of systems, including the airport terminal, while being less realistic than analytical models, is less costly than operational Exercise.In this study, a supportive approach for better and specific management of Iranian airport terminal buildings with discrete-event simulation is proposed, considering the need for managing the airport terminals building in the country and... 

    Gaining Competitive Advantage through Marketing Strategies in Container Terminal: A Case Study on Shahid Rajaee Port in Iran

    , M.Sc. Thesis Sharif University of Technology Cheraghi, Hossein (Author) ; Miremadi, Ali Reza (Supervisor)
    The competitiveness of a port convinced shipping lines and shippers with a significant basis in selecting a port. Port authorities and port operators can make use of the competitive advantage as a parameter for counter measures by grasping the advantages and disadvantages of the ports and be a prime factor of opportunities and threats of the ports. Ports have a significant role in today’s networked business environment. They are being regarded as hubs that are part of various logistic systems. The very essence of a seaport is to link maritime networks and land network. These networks for the port are means of analyzing its competitiveness. A port overall competitiveness is determined by it’s... 

    A Systematic Model to Determine Minimum Separation for VToL in Terminal Phase

    , M.Sc. Thesis Sharif University of Technology Adeli Koudehi, Ali (Author) ; Malaek, Mohammad Bagher (Supervisor)
    For the VTOL aircraft mission profiles, terminal phases are considered the most crucial and convoluted due to the interrelated aspects involved in transition from level flight into vertical motion. Flight safety is the trivial, yet essential requisite that should be satisfied during all flight phases. This paper aims to present a comprehensive model for determining a safe distance for urban VTOL air taxies during the landing phase through predicting possible conflictions and reducing this possibility by performing a conflict resolution maneuver while maintaining the flight safety requirements.The safe distance during landing is calculated based on a Monte-Carlo simulation which employs the... 

    Investigation of E-Vtol Performance Parameters on the Characteristics of Civil Air-Taxi Network

    , M.Sc. Thesis Sharif University of Technology Kiani, Arash (Author) ; Malaek, Mohammad Bagher (Supervisor)
    Nowadays more than half of the world’s population lived in urban areas. That proportion is set to rise to 67% by 2050. This will cause urban mobility with serious problems. The concept of Urban Air Mobility (UAM) is proposed to avoid the problem to become a catastrophy. Due to environmental issues and also high operating costs, using copters as an air-taxi was not justifiable. As the technology in e-VTOL flourished, the desire of using of these vehicles in such a transportation system was increased. In this paper, besides previous investigations, the e-VTOL’s performance parameters’ influence on the characteristic of a civil air-taxi network is under investigation. In addition, this paper... 

    Evaluation of Exerted Drag Force on Alkane Saturated Air Bubbles in Aqueous Solutions by Experimental Studies

    , M.Sc. Thesis Sharif University of Technology Rajabzadeh Dezfuli, Mehdi (Author) ; Bastani, Dariush (Supervisor) ; Lotfi, Marzieh (Supervisor)
    Interfacial phenomena and properties of interphase surfaces in dynamic mode play an important role in industrial processes that include gas-liquid and liquid-liquid multiphase flows. As well as, interface knowledge leads to better understanding of natural and fundamental phenomena. The present study has been performed for understanding about dynamic behavior of interphase surfaces in the presence of nanoparticles and hexane vapor in gas-liquid dispersion systems. In this research, rising bubble method has been used as one of the most conventional techniques. Accordingly, aqueous solutions of nanosilica were prepared in concentrations of 50, 100, 200, 400 and 1200 ppm as continuous phase... 

    Combination of Linear MPC and Differential Game Theory for Optimal Cooperative Terminal Guidance Law with HIL Simulation

    , M.Sc. Thesis Sharif University of Technology Akbari, Mohammad Sadegh (Author) ; Nobahari, Hadi (Supervisor)
    In this research, a cooperative terminal guidance algorithm has been derived for simultaneous multi-interceptor collision with a target. This algorithm is obtained using the combination of model predictive control method and differential game theory. One of the features of this method is the calculation of the optimal guidance command in the form of an explicit relationship. Another feature of this method is its resistance to disturbances due to the use of differential game theory. The first innovation of this research is the use of this hybrid method to create a guidance algorithm, even in the non-cooperative guidance problem. The next innovation is in creating a cooperative terminal... 

    The Simultaneous Berth and Quay Crane Scheduling

    , M.Sc. Thesis Sharif University of Technology Zokaei Nikoo, Maryam (Author) ; Salmasi, Naser (Supervisor)
    This study addresses the simultaneous berth and quay crane (QC) scheduling problem in a container terminal. The berths are considered as a continuous area and the vessels arrive dynamically. QCs are allowed to move to other vessels before completing the process on an assigned vessel.The objective function is determined based on the practical applications of the problem. It deals with minimization of sum of the completion time of vessels. In this research, a mathematical model has been developed for the research problem. According to NP-hardness of the research problem, two meta heuristic algorithms based on Tabu Search are proposed. To solve the problem, these methods have two layers with... 

    Terminal Flight Path Optimization Pattern for High Traffic Airports for Noise

    , M.Sc. Thesis Sharif University of Technology Mostaghimi Rezazade, Saeed (Author) ; Malaek, Mohammad Bagher (Supervisor)
    The only problem in aviation and airport development is the noise print on population groups surrounding airports due to its high frequency it is so annoying for human ear. In order to overcome this problem technology has reached its edge and the only alternative is to deviate terminal flight path.In this thesis I tried find a pattern for optimizing terminal flight path considering a Boeing 737-800 taking off from Mehrabad airport’s runway 29. To do this we were in need of a huge database of airplane low speed model, geographic information and population knowledge.The common approaches used by FAA and other international organizations for modeling low speed flight were used. The influence of... 

    A 3D path planning algorithm based on PSO for autonomous UAVs navigation

    , Article 9th International Conference on Bioinspired Optimization Methods and Their Applications, BIOMA 2020, 19 November 2020 through 20 November 2020 ; Volume 12438 LNCS , 2020 , Pages 268-280 Mirshamsi, A ; Godio, S ; Nobakhti, A ; Primatesta, S ; Dovis, F ; Guglieri, G ; Sharif University of Technology
    Springer Science and Business Media Deutschland GmbH  2020
    In this paper, a new three-dimensional path planning approach with obstacle avoidance for UAVs is proposed. The aim is to provide a computationally-fast on-board sub-optimal solution for collision-free path planning in static environments. The optimal 3D path is an NP (non-deterministic polynomial-time) hard problem which may be solved numerically by global optimization algorithms such as the Particle Swarm Optimization (PSO). Application of PSO to the 3D path planning class of problems faces typical challenges such slow convergence rate. It is shown that the performance may be improved markedly by implementing a novel parallel approach and incorporation of new termination conditions.... 

    TSRN: A tabu search-based routing protocol for named data networking

    , Article Wireless Personal Communications ; Volume 101, Issue 3 , 2018 , Pages 1411-1428 ; 09296212 (ISSN) Shariat, Z ; Movaghar, A ; Hosseinzadeh, M ; Sharif University of Technology
    Springer New York LLC  2018
    Information-centric network (ICN) has become a basic research topic with regard to the future architecture of the Internet. Storage and routing data is an important feature of ICN, as it improves network performance and content distribution. One of the challenges in this type of network is the routing problem. The objective of this paper is to propose a routing algorithm in the named data network. Owing to the impressive results presented by the enhanced heuristic methods, tabu search has been selected to develop the proposed algorithm. This work has been carried out in five major steps, Creating the initial solution, The mechanisms of generating a neighborhood, Evaluating the neighbor... 

    Dynamic Gossip

    , Article Bulletin of the Iranian Mathematical Society ; Volume 45, Issue 3 , 2019 , Pages 701-728 ; 10186301 (ISSN) van Ditmarsch, H ; van Eijck, J ; Pardo, P ; Ramezanian, R ; Schwarzentruber, F ; Sharif University of Technology
    Springer International Publishing  2019
    A gossip protocol is a procedure for spreading secrets among a group of agents, using a connection graph. The goal is for all agents to get to know all secrets, in which case we call the execution of the protocol successful. We consider distributed and dynamic gossip protocols. In distributed gossip, the agents themselves instead of a global scheduler determine whom to call. In dynamic gossip, not only secrets are exchanged but also telephone numbers (agent identities). This results in increased graph connectivity. We define six such distributed dynamic gossip protocols, and we characterize them in terms of the topology of the graphs on which they are successful, wherein we distinguish... 

    ST-CAC: a low-cost crosstalk avoidance coding mechanism based on three-valued numerical system

    , Article Journal of Supercomputing ; Volume 77, Issue 7 , 2021 , Pages 6692-6713 ; 09208542 (ISSN) Shirmohammadi, Z ; Khorami, A ; Omana, M. E ; Sharif University of Technology
    Springer  2021
    Appearances of specific transition patterns during data transfer in bus lines of modern high-performance computing systems, such as communicating structures of accelerators for deep convolutional neural networks, commercial Network on Chips, and memories, can lead to crosstalk faults. With the shrinkage of technology size, crosstalk faults occurrence boosts and leads to degradation of reliability and performance, as well as the increasing power consumption of lines. One effective way to alleviate crosstalk faults is to avoid the appearance of these specific transition patterns by using numerical-based crosstalk avoidance codes (CACs). However, a serious problem with numerical-based CACs is... 

    A new method for design of fixed wing micro air vehicle

    , Article Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering ; Volume 229, Issue 5 , April , 2015 , Pages 837-850 ; 09544100 (ISSN) Hassanalian, M ; Khaki, H ; Khosravi, M ; Sharif University of Technology
    SAGE Publications Ltd  2015
    This study attempts to present a new and comprehensive cycle for the design of fixed wing micro air vehicles. The idea is to propose a complete cycle containing all micro air vehicles design subjects such as aerodynamics, stability, structure, and navigation. The main aim of the cycle is to decrease the designing time for an optimum design. In this method, the sizing process is started simultaneously, which involves the following cases: specification of mission and aviation plan; determination of planform and aspect ratio; constraint analysis; estimation of plane weight. Completion of these four phases results in the specification of the geometry and dimensions of the wing in an optimum... 

    Cellulose-immobilized NHC-Cu(i) complex: An efficient and reusable catalyst for multicomponent synthesis of 1,2,3-triazoles

    , Article RSC Advances ; Volume 5, Issue 120 , Nov , 2015 , Pages 99498-99501 ; 20462069 (ISSN) Pourjavadi, A ; Habibi, Z ; Sharif University of Technology
    Royal Society of Chemistry  2015
    A novel cellulose supported copper NHC complex has been prepared by the reaction of cellulose supported imidazolium salt with copper(i) iodide. The catalyst is active in the synthesis of 1,2,3-triazoles via a one-pot reaction of alkyl/benzyl halides or tosylates and terminal alkynes, with sodium azide in water  

    Graphene oxide/poly(vinyl imidazole) nanocomposite: An effective support for preparation of highly loaded heterogeneous copper catalyst

    , Article Applied Organometallic Chemistry ; Volume 29, Issue 9 , June , 2015 , Pages 601-607 ; 02682605 (ISSN) Pourjavadi, A ; Safaie, N ; Hosseini, S. H ; Bennett, C ; Sharif University of Technology
    John Wiley and Sons Ltd  2015
    A heterogeneous polymeric catalyst was synthesized by immobilization of copper ions in a graphene oxide/poly(vinyl imidazole) nanocomposite. This catalyst has proven to be highly active in a practical protocol for click synthesis of 1,2,3-triazole via one-pot three-component cycloaddition of halides, terminal alkynes and sodium azide. The reaction was carried out in water medium and good to excellent yields of products were obtained using only 1.0 mol% of catalyst. The catalyst can be readily recovered and reused eight times under the described reaction conditions without significant loss of activity. The reaction also proceeded well with only 0.002 mol% of catalyst, which shows the high... 

    Design of an RMPC with a time-varying terminal constraint set for tracking problem

    , Article International Journal of Robust and Nonlinear Control ; Volume 26, Issue 12 , 2016 , Pages 2623-2642 ; 10498923 (ISSN) Razi, M ; Haeri, M ; Sharif University of Technology
    John Wiley and Sons Ltd  2016
    This paper presents a robust model predictive control algorithm with a time-varying terminal constraint set for systems with model uncertainty and input constraints. In this algorithm, the nonlinear system is approximated by a linear model where the approximation error is considered as an unstructured uncertainty that can be represented by a Lipschitz nonlinear function. A continuum of terminal constraint sets is constructed off-line, and robust stability is achieved on-line by using a variable control horizon. This approach significantly reduces the computational complexity. The proposed robust model predictive controller with a terminal constraint set is used in tracking set-points for... 

    Investigation of the impact of synthesized hydrophobic magnetite nanoparticles on mass transfer and hydrodynamics of stagnant and stirred liquid–liquid extraction systems

    , Article Chemical Engineering Research and Design ; Volume 147 , 2019 , Pages 305-318 ; 02638762 (ISSN) Hatami, A ; Azizi, Z ; Bastani, D ; Sharif University of Technology
    Institution of Chemical Engineers  2019
    The impact of modified magnetite nanoparticles (MMNPs)on hydrodynamics and mass transfer in liquid–liquid extraction process was assessed using a ternary chemical system of toluene-acetic acid–water. The organic phase which contained toluene and acetic acid was dispersed through water, and the mass transfer of acetic acid between two phases was investigated. The hydrophobic modified magnetite nanoparticles (MMNPs)prepared through an optimized in-situ method were added to the dispersed phase at different concentrations (0.001−0.005 wt%). Two separate conditions were provided in the experiments, i.e. stagnant and stirred continuous phase. The latter case was provided by a rotor at two... 

    A robust finite-time hyperchaotic secure communication scheme based on terminal sliding mode control

    , Article 24th Iranian Conference on Electrical Engineering, ICEE 2016, 10 May 2016 through 12 May 2016 ; 2016 , Pages 854-858 ; 9781467387897 (ISBN) Abooee, A ; Moravej Khorasani, M ; Haeri, M ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2016
    In this paper, a new robust finite-time hyperchaotic secure communication scheme is proposed by combining robust finite-time synchronization of two hyperchaotic systems and hyperchaotic multiplication masking technique. The mentioned synchronization is achieved by introducing new terminal sliding mode controllers. As a main novelty of the introduced scheme, an adjustable total finite time is obtained such that the decrypted message signal will be completely identical with the transmitted message signal for times larger than the discussed finite time. Compared with other secure communication schemes, the suggested method has several advantages including finite-time stability for dynamical... 

    Multi-party secret key agreement over state-dependent wireless broadcast channels

    , Article IEEE Transactions on Information Forensics and Security ; Volume PP, Issue 99 , 2016 ; 15566013 (ISSN) Jafari Siavoshani, M ; Mishra, S ; Fragouli, C ; Diggavi, S. N ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2016
    We consider a group of m trusted and authenticated nodes that aim to create a shared secret key K over a wireless channel in the presence of an eavesdropper Eve. We assume that there exists a state dependent wireless broadcast channel from one of the honest nodes to the rest of them including Eve. All of the trusted nodes can also discuss over a cost-free, noiseless and unlimited rate public channel which is also overheard by Eve. For this setup, we develop an information-theoretically secure secret key agreement protocol. We show the optimality of this protocol for "linear deterministic" wireless broadcast channels. This model generalizes the packet erasure model studied in literature for...