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    Finite time control of robotic manipulators with position output feedback

    , Article International Journal of Robust and Nonlinear Control ; Volume 27, Issue 16 , 2017 , Pages 2982-2999 ; 10498923 (ISSN) Abooee, A ; Moravej Khorasani, M ; Haeri, M ; Sharif University of Technology
    This paper deals with the robust finite time tracking of desired trajectories for a wide group of robotic manipulators in spite of unknown disturbances, uncertainties, and saturations of actuators while only manipulator's positions are available and its velocities are not measurable physically. A new form of chattering-free second order fast nonsingular terminal sliding mode control scheme is introduced to design input torques for fulfilling the determined tracking objective in the adjustable total finite settling time. The proposed control algorithm is incorporated with two nonlinear observers to estimate disturbances and velocities of joints within finite settling times. The global finite... 

    Closed-loop powered-coast-powered predictive guidance for spacecraft rendezvous with non-singular terminal sliding mode steering

    , Article Acta Astronautica ; Volume 166 , 2020 , Pages 507-523 Kasaeian, S. A ; Ebrahimi, M ; Assadian, N ; Sharif University of Technology
    Elsevier Ltd  2020
    The present study aims to present a guidance algorithm based on the relative motion prediction for orbital rendezvous, in which a coast phase is allowed between two powered phases. In both powered phases, the solution of the Hill-Clohessy-Wiltshire equations is used to find the required state variables at each time instant. To track the required trajectory and compensate for any orbital perturbations and uncertainties, a non-singular terminal sliding mode method is utilized as the steering law. Then, the finite time convergence of the state variables is mathematically proved. In addition, the starting time of the second powered phase is adapted to perturbations and uncertainties by another... 

    Design of a continuous fractional-order nonsingular terminal sliding mode control with time delay estimation for fes control of human knee joint

    , Article 7th International Conference on Control, Instrumentation and Automation, ICCIA 2021, 23 February 2021 through 24 February 2021 ; 2021 ; 9780738124056 (ISBN) Karami, M ; Abbasi, M ; Vossoughi, G ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2021
    The design of a novel Continuous Fractional-Order Nonsingular Terminal Sliding Mode controller is the focus of this study. Time Delay Estimation technique is incorporated into the controller. The proposed method is responsible for controlling the human knee joint neuromusculoskeletal model via Functional Electrical Stimulation. A second-order nonlinear model with time-varying coefficients is used for characterizing the FES-stimulated neuromusculoskeletal model. The presence of time-varying coefficients often complicates precise control of knee joint through FES and impairs the performance of conventional methods. To this end, the TDECFONTSM has been proposed consisting of three components, a... 

    Solving bus terminal location problems using evolutionary algorithms

    , Article Applied Soft Computing Journal ; Volume 11, Issue 1 , 2011 , Pages 991-999 ; 15684946 (ISSN) Ghanbari, R ; Mahdavi Amiri, N ; Sharif University of Technology
    Bus terminal assignment with the objective of maximizing public transportation service is known as bus terminal location problem (BTLP). We formulate the BTLP, a problem of concern in transportation industry, as a p-uncapacitated facility location problem (p-UFLP) with distance constraint. The p-UFLP being NP-hard (Krarup and Pruzan, 1990), we propose evolutionary algorithms for its solution. According to the No Free Lunch theorem and the good efficiency of the distinctive preserve recombination (DPX) operator, we design a new recombination operator for solving a BTLP by new evolutionary and memetic algorithms namely, genetic local search algorithms (GLS). We also define the potential... 

    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... 

    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... 

    Energy and delay efficient strategies for content distribution using mobile-to-mobile cooperation

    , Article 6th IFIP/IEEE Wireless Days Conference, WD 2013, Valencia, 13 November 2013 through 15 November 2013 ; 2013 ; 21569711 (ISSN); 9781479905423 (ISBN) Bagheri, H ; Salehi, M. J ; Barua, B ; Khalaj, B. H ; Katz, M ; Sharif University of Technology
    IEEE Computer Society  2013
    In this paper we consider the content distribution to a set of mobile users interested in the same content. We use the concept of mobile clouds, which exploits cooperation between mobile terminals over the low-power short-range links. We propose, formulate and investigate the energy efficiency and delay of four realistic cooperative content delivery strategies. The derived results, through analysis of mathematical models and simulations, demonstrate around 65% to 95% energy saving gain in mobile cloud strategies compared to conventional multicasting. We also show that using mobile clouds, content distribution delay can be reduced for up to 85%  

    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... 

    A logit-based model for facility placement planning in supply chain management

    , Article International Journal of Logistics Systems and Management ; Volume 20, Issue 1 , 2015 , Pages 122-147 ; 17427967 (ISSN) Bagloee, S. A ; Shnaiderman, M ; Tavana, M ; Ceder, A ; Sharif University of Technology
    Inderscience Enterprises Ltd  2015
    The facility placement in supply chain management entails suppliers and consumers along with the terminals in between for distributing commodities. This study seeks to find the best terminal placement by taking into consideration the costs for both transportation and terminal construction. We call this a supplier-terminal-consumer (STC) problem and show that the STC is an NP-hard quadratic assignment problem. The NP-hard problems in real-size are proven to be intractable; hence, we develop a two-fold heuristic method for solving the STC problems. First, we identify the commodity flow by using a logit-based mathematical programming (Logit-MP) methodology based on the demand for the commodity... 

    Multi-antenna coded caching

    , Article IEEE International Symposium on Information Theory - Proceedings, 25 June 2017 through 30 June 2017 ; 2017 , Pages 2113-2117 ; 21578095 (ISSN) ; 9781509040964 (ISBN) Shariatpanahi, S. P ; Caire, G ; Khalaj, B. H ; Sharif University of Technology
    In this paper we consider a single-cell downlink scenario where a multiple-antenna base station delivers contents to multiple cache-enabled user terminals. Based on the multicasting opportunities provided by the so-called Coded Caching technique, we investigate three delivery approaches. Our baseline scheme employs the coded caching technique on top of max-min fair multicasting. The second one consists of a joint design of Zero-Forcing (ZF) and coded caching, where the coded chunks are formed in the signal domain (complex field). The third scheme is similar to the second one with the difference that the coded chunks are formed in the data domain (finite field). We derive closed-form rate... 

    Predicting the competitive position of extended gates: The case of inland customs zones

    , Article European Journal of Transport and Infrastructure Research ; Volume 18, Issue 4 , 2018 , Pages 433-456 ; 15677141 (ISSN) Sherafatipour, S ; Saffarzadeh, M ; Tavasszy, L ; Fatemi Ardestani, S. F ; Sharif University of Technology
    Editorial Board EJTIR  2018
    The extended gate concept aims to reduce the pressure on international ports by postponing administrative processes from these border gates to inland terminals. At present, this approach is used mainly in the container transport industry in European and Asian ports. In this paper we study an extended gate concept, where inland customs services are made available from all entry points of a country. Our aim is to predict the portion of the current flow through border gates that is diverted to these inland customs zones. We propose a time-series gravity models to predict these changes and estimate the parameters of this model using publicly available data for different cargo groups. The focus... 

    An MP-based approximation algorithm on reliability evaluation of multistate flow networks

    , Article Reliability Engineering and System Safety ; Volume 191 , 2019 ; 09518320 (ISSN) Forghani Elahabad, M ; Kagan, N ; Mahdavi Amiri, N ; Sharif University of Technology
    Elsevier Ltd  2019
    In recent decades, multistate two-terminal reliability problem has attracted several researchers, and accordingly many exact and approximation approaches have been proposed in the literature in terms of minimal cuts (MCs) or minimal paths (MPs) to address this problem. Here, an MP-based approximation approach is developed based on exact algorithms. With all the MPs at hand, the approach rearranges the MPs ascendingly with respect to their lengths and then sets the flow on some MPs to be zero which turns to reduce the computing cost in solving the problem. We provide the complexity results, and by employing some benchmarks and one thousand randomly generated networks illustrate that not only... 

    Linear multicast beamforming schemes for coded caching

    , Article 52nd Asilomar Conference on Signals, Systems and Computers, ACSSC 2018, 28 October 2018 through 31 October 2018 ; Volume 2018-October , 2019 , Pages 172-176 ; 10586393 (ISSN); 9781538692189 (ISBN) Tolli, A ; Kaleva, J ; Shariatpanahi, S. P ; Khalaj, B ; Matthews M. B ; Sharif University of Technology
    IEEE Computer Society  2019
    A single cell downlink scenario is considered, where a multiple-antenna base station delivers contents to cache-enabled user terminals. Depending on the available degrees of freedom, several multicast messages are transmitted in parallel to distinct subsets of users. In the multicast beamformer design, we restrict ourselves to linear receiver implementation, which does not require successive interference cancellation unlike in the more optimal baseline scheme. With a small loss in performance, the complexity of both the receiver and transmitter implementation can be significantly reduced. © 2018 IEEE  

    Rapid depressurization dynamics of solid propellant rocket motors

    , Article 43rd AIAA/ASME/SAE/ASEE Joint Propulsion Conference, Cincinnati, OH, 8 July 2007 through 11 July 2007 ; Volume 8 , 2007 , Pages 7871-7879 ; 1563479036 (ISBN); 9781563479038 (ISBN) Tahsini, A. M ; Farshchi, M ; Sharif University of Technology
    American Institute of Aeronautics and Astronautics Inc  2007
    Transient internal ballistics of a solid propellant rocket motor during rapid depressurization due to opening of an auxiliary nozzle for active thrust termination has been considered in this work. Prediction of thrust termination and reversing dynamics is required for successful stage separation in multi-stage rockets. Quasi one-dimensional unsteady Euler equation with a transient propellant burning model that accounts for the effects of time rate of change of the chamber pressure on the burning rate have been used to simulate the internal ballistics of a rocket motor. The compressible convective flow solver used in this study is based on Roe's scheme. The effects of rapid chamber pressure... 

    A probabilistic approach for remote terminal unit placement in power distribution systems

    , Article INTELEC, International Telecommunications Energy Conference (Proceedings) ; 2011 ; 02750473 (ISSN) ; 9781457712494 (ISBN) Razi Kazemi, A. A ; Dehghanian, P ; Karami, G ; Sharif University of Technology
    This paper investigates a reliability-centered approach for the placement procedure of remote terminal units (RTUs) in power distribution systems. Entire attempt is contributed to incorporate the practical aspects interrelated with the problem, e.g. the accessibility to the candidate substations, the load point criticality, as well as the load probabilistic behavior and consequently the inevitable variation in the electricity price. The placement process is done through an optimization problem wherein the common reliability indices, as the decisive factors in the placement process, are going to be minimized. The approach is successfully applied to a real power distribution feeder of Iran's... 

    Multimedia multicast based on multiterminal source coding

    , Article IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences ; Volume E93-A, Issue 9 , 2010 , Pages 1639-1649 ; 09168508 (ISSN) Aghagolzadeh, A ; Nooshyar, M ; Rabiee, H. R ; Mikaili, E ; Sharif University of Technology
    Multimedia multicast with two servers based on the mul- titerminal source coding is studied in some previous researches. Due to the possibility of providing an approach for practical code design for more than two correlated sources in IMTSC/CEO setup, in this paper, the framework of Slepian-Wolf coded quantization is extended and a practical code design is presented for IMTSC/CEO with the number of encoders greater than two. Then the multicast system based on the IMTSC/CEO is applied to the cases with three, four and five servers. Since the underlying code design approach for the IMTSC/CEO problem has the capability of applying to an arbitrary number of active encoders, the proposed MMBMSC... 

    Finite-Time guidance laws for landing process of a spacecraft subjected to disturbances

    , Article 2016 4th International Conference on Control, Instrumentation, and Automation, ICCIA 2016, 27 January 2016 through 28 January 2016 ; 2016 , Pages 296-300 ; 9781467387040 (ISBN) Abooee, A ; Moravej Khorasani, M ; Haeri, M ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2016
    This paper investigates the finite-Time landing of a spacecraft on a celestial target subjected to disturbances and air drag forces. Based on nonsingular fast terminal sliding mode control, a novel guidance law is designed to accomplish the landing goal within a specified finite time while the upper bound of disturbances is assumed to be known. Finally, a numerical example of the spacecraft landing problem is simulated by applying the proposed scheme. The obtained results illustrate that the designed guidance law can achieve the landing goal in the specified finite time  

    Identification of a novel multifunctional ligand for simultaneous inhibition of amyloid-beta (aβ42) and chelation of zinc metal ion

    , Article ACS Chemical Neuroscience ; Volume 10, Issue 11 , 2019 , Pages 4619-4632 ; 19487193 (ISSN) Asadbegi, M ; Shamloo, A ; Sharif University of Technology
    American Chemical Society  2019
    Zinc binding to β-amyloid structure could promote amyloid-β aggregation, as well as reactive oxygen species (ROS) production, as suggested in many experimental and theoretical studies. Therefore, the introduction of multifunctional drugs capable of chelating zinc metal ion and inhibiting Aβ aggregation is a promising strategy in the development of AD treatment. The present study has evaluated the efficacy of a new bifunctional peptide drug using molecular docking and molecular dynamics (MD) simulations. This drug comprises two different domains, an inhibitor domain, obtained from the C-terminal hydrophobic region of Aβ, and a Zn2+ chelating domain, derived from rapeseed meal, merge with a... 

    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...