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Prediction of aerial-image motion blurs due to the flying vehicle dynamics and camera characteristics in a virtual environment
, Article Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering ; Volume 227, Issue 7 , 2013 , Pages 1055-1067 ; 09544100 (ISSN) ; Malaek, S. M. B ; Sharif University of Technology
2013
Abstract
This study presents comprehensive studies on practical means to predict aerial-image motion blurs due to the flying vehicle dynamics, including flying altitude; cruising speed; and angular velocities and finally installed camera characteristics; such as, frame rate and image size. The resulting predictions of blur values are in-turn used to generate blurry images to be fed as input data for later use in a de-blurring-in-the-loop of a Mono-simultaneous localization and mapping system. The whole process is coordinated by means of an integrated aerial virtual environment. The integrated aerial virtual environment consists of a three-dimensional graphical engine which could communicate with a...
An integrated virtual environment for feasibility studies and implementation of aerial MonoSLAM
, Article Virtual Reality ; Volume 16, Issue 3 , September , 2012 , Pages 215-232 ; 13594338 (ISSN) ; Malaek, S. M. B ; Sharif University of Technology
2012
Abstract
This work presents a complete framework of an integrated aerial virtual environment (IAVE), which could effectively help implementing MonoSLAM (single-camera simultaneous localization and mapping) on an aerial vehicle. The developed system allows investigating different flight conditions without using any preloaded maps or predefined features. A 3D graphical engine integrated with a full 6 DOF aircraft dynamic simulator together with its trajectory generator completes the package. The 3D engine generates and accumulates real-time images of a general camera installed on the aerial vehicle. We effectively exploit C++ to develop the 3D graphics engine (3DGE) and all its associated visual...
A simulation environment for path and image generation in an aerial single-camera vision system
, Article Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering ; Volume 225, Issue 5 , 2011 , Pages 541-558 ; 09544100 (ISSN) ; Malaek, S. M. B ; Sharif University of Technology
2011
Abstract
This work describes the essential tools and architecture of a simulation environment, which could help enhance general aviation training as well as safety issues, especially while dealing with flights over unfamiliar environments. It also describes how the authors could effectively generate any desired flight path and its associated surrounding images through implementing a virtual single camera with simultaneous localization and mapping (monocular simultaneous localization and mapping) techniques. The overall package enjoys an aerial three-dimensional (3D)/graphical engine integrated with a full six-degrees-of-freedom aircraft dynamics, which serves as its trajectory generator, together...
Integration of image de-blurring in an aerial Mono-SLAM
, Article Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering ; Vol. 228, issue. 8 , May , 2014 , p. 1348-1362 ; Gholampour, P ; Malaek, S. M. B ; Sharif University of Technology
2014
Abstract
In this article, we discuss the possibility of integrating image de-blurring techniques in an aerial simultaneous localization and mapping by a single camera (monocular simultaneous localization and mapping (Mono-SLAM)). We use an integrated aerial virtual environment together with a six-degree-of-freedom aircraft flight simulator to show the effectiveness of the approach to generate three-dimensional flight trajectories via integration of image de-blurring in the associated loop of the Mono-SLAM. The objective is to increase the overall performance of a flying mission over an unknown area by means of a vision-only method. The integrated aerial virtual environment produces and collects...
PBN-Based time-optimal terminal air traffic control using cellular automata
, Article IEEE Transactions on Aerospace and Electronic Systems ; Volume 57, Issue 3 , 2021 , Pages 1513-1523 ; 00189251 (ISSN) ; Amiri Atashgah, M. A ; Malaek, S. M. B ; Thulasiraman, P ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2021
Abstract
Over the last decade, there has been an increase in air transportation, which has raised awareness to provide necessary procedures to respond to air transportation demands and reduce delay costs. One such procedure, 'performance-based navigation (PBN),' currently studied, is expected to increase the airspace capacity based on aircraft's individual performances. This research describes an efficient and expandable model for allocating standard terminal arrival route during continuous descent approach (CDA) that effectively uses PBN requirements. As a case study, we have considered the 'Atlanta International Airport' and verified the model's accuracy using real-time traffic data. The model is...
A secure and efficient chaotic maps based authenticated key-exchange protocol for smart grid
, Article Wireless Personal Communications ; Volume 97, Issue 2 , 2017 , Pages 2551-2579 ; 09296212 (ISSN) ; Beheshti Atashgah, M ; Aref, M. R ; Sharif University of Technology
2017
Abstract
Nicanfar and Leung proposed a multilayer consensus elliptic curve based password authenticated key-exchange (MCEPAK) protocol for smart grid. They claimed that their protocol is secure against possible attacks. In this paper, we show that the MCEPAK protocol is vulnerable to the dictionary attack and an adversary can obtain the passwords of the appliances by eavesdropping the communicated messages in the protocol. Moreover, we state that the passwords can be discovered by curious operators of the building area networks and the neighbor area networks. Theses weaknesses motivated us to introduce a chaotic maps based authenticated key exchange protocol for smart grid. To the best of our...
Improvement on Q. Xie threshold proxy signature scheme against collusion attack
, Article 2011 19th Iranian Conference on Electrical Engineering, ICEE 2011, 17 May 2011 through 19 May 2011 ; May , 2011 , Page(s): 1 - 5 ; ISSN : 21647054 ; 9789644634284 (ISBN) ; Bayat, M ; Gardeshi, M ; Aref, M. R ; Sharif University of Technology
2011
Abstract
In a (t, n) threshold proxy signature scheme, the original signer can delegate the signing power to n proxy signers such that any t or more out of n proxy signers can sign messages on behalf of the original signer, but t -1 or less of the proxy signers cannot generate a proxy signature. In this paper, we will improve the security of Xie's threshold proxy signature scheme against the new types of collusion attack was presented by Liu and Tan in 2007 We also present that our improved scheme is more efficient than Xie's scheme in terms of computational complexities
A novel lattice-based proxy signature scheme
, Article ICEE 2012 - 20th Iranian Conference on Electrical Engineering, 15 May 2012 through 17 May 2012 ; May , 2012 , Pages 1224-1227 ; 9781467311489 (ISBN) ; Ajori, M ; Gardeshi, M ; Aref, M. R ; Sharif University of Technology
2012
Abstract
In a proxy signature scheme, an original signer delegates his/her signing capability to a proxy signer and then the proxy signer can sign messages on behalf of the original signer. The security of many proxy signature schemes that have been proposed depends, either directly or indirectly, on either the difficulty of big integers factoring problem or the difficulty of finding discrete logarithm in a finite group. These types of schemes cannot resist quantum attacks. In this paper, we propose a new lattice-based proxy signature scheme which can resist quantum attacks. The proposed scheme is based on the GGH-signature scheme and also satisfies all the security requirements of proxy signature...
ID-based strong designated verifier signature scheme and its applications in internet of things
, Article 27th Iranian Conference on Electrical Engineering, ICEE 2019, 30 April 2019 through 2 May 2019 ; 2019 , Pages 1486-1491 ; 9781728115085 (ISBN) ; Aref, M. R ; Bayat, M ; Barari, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
Strong designated verifier signature scheme is a concept in which a user (signer) can issue a digital signature for a special receiver; i.e. signature is produced in such way that only intended verifier can check the validity of produced signature. Of course, this type of signature scheme should be such that no third party is able to validate the signature. In other words, the related designated verifier cannot assign the issued signature to another third party. This article proposes a new ID-based strong designated verifier signature scheme which has provable security in the ROM (Random Oracle Model) and BDH assumption. The proposed scheme satisfies the all security requirements of an...
An ultra-lightweight RFID mutual authentication protocol
, Article 16th International ISC (Iranian Society of Cryptology) Conference on Information Security and Cryptology, ISCISC 2019, 28 August 2019 through 29 August 2019 ; 2019 , Pages 27-32 ; 9781728143736 (ISBN) ; Beheshti Atashgah, M ; Eghlidos, T ; Aref, M. R ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
In some applications of the Internet of Things (IoT), for privacy preserving and authentication of entities, it is necessary to use ultra-lightweight cryptographic algorithms. In this paper, we propose a new ultra-lightweight authentication protocol between RFID components, in which only simple operations are used. In this protocol, the server has access to the data gathered by the tag in the same authentication phase through the reader interface, instead of sharing a secret key. The proposed protocol is secure against several attacks, such as replay attacks, denial of service, offline guessing attacks, modification attacks, full disclosure attacks and impersonation attacks, in addition to...
A lightweight anonymous authentication protocol for IoT wireless sensor networks
, Article 16th International ISC (Iranian Society of Cryptology) Conference on Information Security and Cryptology, ISCISC 2019, 28 August 2019 through 29 August 2019 ; 2019 , Pages 39-44 ; 9781728143736 (ISBN) ; Beheshti Atashgah, M ; Eghlidos, T ; Aref, M. R ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
Lightweight authentication protocols are crucial for privacy preserving in Internet of Things (IoT). Authentication protocols should be implementable for devices with constrained memory and computational power in this area, in addition to resistance against cryptographic threats. On the other hand, these protocols should not impose a heavy computational load on such devices. In this paper we proposed an authentication protocol that properly meets these features. Our protocol is suitable for wireless sensor networks (WSNs). In this protocol, authentication is fulfilled with low communication and computational loads between sensors and users through the gateway interface using a hash function...
Aerial Vision-Based Navigation and Monitoring in Special Conditions
, Ph.D. Dissertation Sharif University of Technology ; Malaek, Mohammad Bagher (Supervisor)
Abstract
This research is dedicated to specific issues in the field of Aerial Vision Based Navigation (VBN). It focuses mainly on vehicles with no pilot such as RPVs and small aircraft; having in mind their safety which must be close to commercial applications. Various methods have been studied and the simplest one; which is based on observation, identification and utilization of landmarks is selected for detailed implementation. In this work, we concentrate on using a single-camera while flying in an unknown environment (MonoSLAM). Other available sensors are accelerometer and GPS receiver to keep the cost down. Different studies show that using a low-cost single camera system is much more efficient...
Butanol Production from Bagasse Sugarcane Black Liquor by Native Strain and Clostridium Acetobutylicum Species
,
M.Sc. Thesis
Sharif University of Technology
;
Shayegan, Jalaleddin
(Supervisor)
;
Vossoughi, Manouchehr
(Supervisor)
;
Sedighi, Mahsa
(Co-Supervisor)
Abstract
Considering the limitations of fossil fuels in recent years, as well as increasing demand for biofuels, it is anticipated that future attention to biofuels will increase further. Among biofuels, due to some disadvantages of bioethanol and biodiesel fuel, there is a tendency to use biobutanol, which does not have the disadvantages of the mentioned fuels. The cost of chemical production of butanol also led researchers to use biotechnology production of butanol. According to studies, butanol production can be achieved by fermenting some sugars such as glucose, xylose, and ... by anaerobic microorganism, but the cost of using these sugars has resulted in the use of natural sources of these...
BF3·SiO2: an efficient reagent system for the one-pot synthesis of 1,2,4,5-tetrasubstituted imidazoles
, Article Tetrahedron Letters ; Volume 49, Issue 16 , 2008 , Pages 2575-2577 ; 00404039 (ISSN) ; Mirjalili, B. B. F ; Hashemi, M. M ; Sharif University of Technology
2008
Abstract
Silica-supported boron trifluoride (BF3·SiO2) is an efficient, readily available and reusable catalyst for the synthesis of 1,2,4,5-tetrasubstituted imidazoles using benzil, an aromatic aldehyde and an amine in the presence of ammonium acetate. This one-pot procedure is very simple, affording good to excellent yields. © 2008 Elsevier Ltd. All rights reserved
Application of Bhattacharyya distance as a dissimilarity index for automated prediction of epileptic seizures in rats
, Article 2010 International Conference on Intelligent and Advanced Systems, ICIAS 2010, 15 June 2010 through 17 June 2010 ; 2010 ; 9781424466238 (ISBN) ; Vosoughi Vahdat, B ; Shamsollahi, M. B ; Sayyah, M ; Sharif University of Technology
2010
Abstract
Seizures are defined as manifest of excessive and hypersynchronous activity of neurons in the cerebral cortex and represent a frequent malfunction of the human central nervous system. Therefore, the search for precursors and predictors of a seizure is of utmost clinical relevance and may even guide us to a deep understanding of the seizure generating mechanisms. In this study we analyzed invasive electroencephalogram (EEG) recordings in rats with experimentally induced generalized epilepsy with a nonlinear method called, dissimilarity index. In order to predict epileptic seizures automatically, Bhattacharyya distance between trajectory matrix of reference window, during an interval quite...
Correlation for Nusselt number in pure magnetic convection ferrofluid flow in a square cavity by a numerical investigation
, Article Journal of Magnetism and Magnetic Materials ; Volume 322, Issue 22 , November , 2010 , Pages 3607-3613 ; 03048853 (ISSN) ; Ebrahimi, B ; Shafii, M. B ; Saidi, M. H ; Saidi, M. S ; Sharif University of Technology
2010
Abstract
Magnetic convection heat transfer in a two-dimensional square cavity induced by magnetic field gradient is investigated numerically using a semi-implicit finite volume method. The side walls of the cavity are heated with different temperatures, the top and bottom walls are isolated, and a permanent magnet is located near the bottom wall. Thermal buoyancy-induced flow is neglected due to the nongravity condition on the plane of the cavity. Conditions for the different values of non-dimensional variables in a variety of ferrofluid properties and magnetic field parameters are studied. Based on this numerical analysis, a general correlation for the overall Nusselt number on the side walls is...
Fetal electrocardiogram R-peak detection using robust tensor decomposition and extended Kalman filtering
, Article Computing in Cardiology ; Volume 40 , 2013 , Pages 189-192 ; 23258861 (ISSN) ; 9781479908844 (ISBN) ; Niknazar, M ; Jutten, C ; Shamsollahi, M. B ; Rivet, B ; Sharif University of Technology
2013
Abstract
In this paper, we propose an efficient method for R-peak detection in noninvasive fetal electrocardiogram (ECG) signals which are acquired from multiple electrodes on mother's abdomen. The proposed method is performed in two steps: first, we employ a robust tensor decomposition-based method for fetal ECG extraction, assuming different heart rates for mother and fetal ECG; then a method based on extended Kalman filter (EKF) in which the ECG beat is modeled by 3 state equations (P, QRS and T), is used for fetal R-peak detection. The results show that the proposed method is efficiently able to estimate the location of R-peaks of fetal ECG signals. The obtained average scores of event 4 and 5 on...
Alterations of the electroencephalogram sub-bands amplitude during focal seizures in the pilocarpine model of epilepsy
, Article Physiology and Pharmacology ; Volume 16, Issue 1 , 2012 , Pages 11-20 ; 17350581 (ISSN) ; Niknazar, M ; Sayyah, M ; babapour, V ; Vahdat, B. V ; Shamsollahi, M. B ; Sharif University of Technology
2012
Abstract
Introduction: Temporal lobe epilepsy (TLE) is the most common and drug resistant epilepsy in adults. Due to behavioral, morphologic and electrographic similarities, pilocarpine model of epilepsy best resembles TLE. This study was aimed at determination of the changes in electroencephalogram (EEG) sub-bands amplitude during focal seizures in the pilocarpine model of epilepsy. Analysis of these changes might help detection of a pre-seizure state before an oncoming seizure. Methods: Rats were treated by scopolamine (1mg/kg, s.c) to prevent cholinergic effects. After 30 min, pilocarpine (380 mg/kg, i.p) was administered to induce status epilepticus (SE) and 2 hours after SE, diazepam (20 mg/kg,...
Analytical solution for creeping motion of a viscoelastic drop falling through a Newtonian fluid
, Article Korea Australia Rheology Journal ; Vol. 26, issue. 1 , 2014 , pp. 91-104 ; ISSN: 1226119X ; Norouzi, M ; Firoozabadi, B ; Sharif University of Technology
2014
Abstract
In this paper, an analytical solution for steady creeping motion of viscoelastic drop falling through a viscous Newtonian fluid is presented. The Oldroyd-B model is used as the constitutive equation. The analytical solutions for both interior and exterior flows are obtained using the perturbation method. Deborah number and capillary numbers are considered as the perturbation parameters. The effect of viscoelastic properties on drop shape and motion are studied in detail. The previous empirical studies indicated that unlike the Newtonian creeping drop in which the drop shape is exactly spherical, a dimpled shape appears in viscoelastic drops. It is shown that the results of the present...
Theoretical and experimental study on the motion and shape of viscoelastic falling drops through Newtonian media
, Article Rheologica Acta ; Volume 55, Issue 11-12 , 2016 , Pages 935-955 ; 00354511 (ISSN) ; Norouzi, M ; Firoozabadi, B ; Sharif University of Technology
Springer Verlag
2016
Abstract
In this paper, creeping motion of a viscoelastic drop falling through a Newtonian fluid is investigated experimentally and analytically. A polymeric solution of 0.08 % xanthan gum in 80:20 glycerol/water and silicon oil is implemented as the viscoelastic drop and the bulk viscous fluids, respectively. The shape and motion of falling drops are visualized using a high speed camera. The perturbation technique is employed for both interior and exterior flows, and Deborah and capillary numbers are considered as perturbation parameters up to second order. The product of Deborah and capillary numbers is also used as a perturbation parameter to apply the boundary condition on the deformation on the...