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Utilizing the moiré deflectometry-based detection method improves the detection sensitivity for gold nanoparticles trapped by optical tweezers
, Article Journal of the Optical Society of America B: Optical Physics ; Volume 38, Issue 7 , 2021 , Pages 2135-2140 ; 07403224 (ISSN) ; Khorshad, A. A ; Sharif University of Technology
The Optical Society
2021
Abstract
Gold nanoparticles (GNPs) are very often used as handles for nanotechnological micromanipulation. In this regard, optical trapping of GNPs is of great importance, in which locating the trapped GNP within the focal spot with nanometer precision is crucial. Very recently, we have introduced a new position detection system for optical tweezers based on moiré deflectometry (MD). Here we show, both theoretically and experimentally, that an MD detection system could provide significantly larger detection sensitivity for a trapped GNP compared to that provided by conventional back focal plane (BFP) detection systems. For instance, for a trapped 200 nm GNP, the detection sensitivity provided by the...
Wardrop's first principle: Extension for capacitated networks
, Article Scientia Iranica ; Volume 28, Issue 1 , 2021 , Pages 175-191 ; 10263098 (ISSN) ; Poorzahedy, H ; Nourinejad, M ; Sharif University of Technology
Sharif University of Technology
2021
Abstract
In transportation literature, User Equilibrium (UE) has been widely studied since early 1950's, many studies of which define equilibrium flow of traffic for uncapacitated networks based on Wardrop's first principle, implying also a Nash Equilibrium (NE). Although, in general, the two equilibria (UE and NE) are not explicitly the same, they are shown to be equivalent under special conditions for uncapacitated UE, when volume delay functions are separable, continuous, non-decreasing and non-negative. A good deal of research is devoted to explain UE in capacitated networks based on Wardrop's first principle and the concept of generalized costs. However, UE for capacitated networks, even under...
Wardrop's first principle: Extension for capacitated networks
, Article Scientia Iranica ; Volume 28, Issue 1 , 2021 , Pages 175-191 ; 10263098 (ISSN) ; Poorzahedy, H ; Nourinejad, M ; Sharif University of Technology
Sharif University of Technology
2021
Abstract
In transportation literature, User Equilibrium (UE) has been widely studied since early 1950's, many studies of which define equilibrium flow of traffic for uncapacitated networks based on Wardrop's first principle, implying also a Nash Equilibrium (NE). Although, in general, the two equilibria (UE and NE) are not explicitly the same, they are shown to be equivalent under special conditions for uncapacitated UE, when volume delay functions are separable, continuous, non-decreasing and non-negative. A good deal of research is devoted to explain UE in capacitated networks based on Wardrop's first principle and the concept of generalized costs. However, UE for capacitated networks, even under...
Ranking locations for hydrogen production using hybrid wind-solar: a case study
, Article Sustainability (Switzerland) ; Volume 13, Issue 8 , 2021 ; 20711050 (ISSN) ; Mostafaeipour, A ; Jahanshahi, E ; Jooyandeh, E ; Himri, Y ; Jahangiri, M ; Issakhov, A ; Chowdhury, S ; Hosseini Dehshiri, J ; Hosseini Dehshiri, S ; Techato, K ; Sharif University of Technology
MDPI
2021
Abstract
Observing the growing energy demand of modern societies, many countries have rec-ognized energy security as a looming problem and renewable energies as a solution to this issue. Renewable hydrogen production is an excellent method for the storage and transfer of energy generated by intermittent renewable sources such as wind and solar so that they can be used at a place and time of our choosing. In this study, the suitability of 15 cities in Fars province, Iran, for renewable hydrogen production was investigated and compared by the use of multiple multi-criteria decision-making methods including ARAS, SAW, CODAS, and TOPSIS. The obtained rankings were aggregated by rank averaging, Borda...
An Intrusion Detection System for Wormhole Attack Detection in MANETs
, M.Sc. Thesis Sharif University of Technology ; Movaghar, Ali (Supervisor)
Abstract
Mobile ad hoc networks (MANETs) have been attracting the attention of the researchers in the duration of last years. Because of lack of infrastructure in such networks, all network operations such as routing are done by the nodes themselves. On the other hand, standard MANETs' routing protocols suppose that all nodes are trusted. Thus, these protocols are prone to serious security attack. Wormhole attack is one of the attacks which abuse distributed routing in MANETs. This attack is held between two malicious nodes which are far away from each other. Mentioned nodes introduce themselves as one-hop neighbor of each other. Therefore, they deceive normal nodes and disturb the routing mechanism....
Localizing exception faults in Android applications
, Article Scientia Iranica ; Volume 26, Issue 3 D , 2019 , Pages 1567-1588 ; 10263098 (ISSN) ; Heydarnoori, A ; Sharif University of Technology
Sharif University of Technology
2019
Abstract
In software programs, most of the time, there is a chance for occurrence of faults in general, and exception faults in particular. Localizing those pieces of code that are responsible for a particular fault is one of the most complicated tasks, and it can produce incorrect results if done manually. Semi-automated and fully-automated techniques have been introduced to overcome this issue. However, despite recent advances in fault localization techniques, they are not necessarily applicable to Android applications because of their special characteristics such as context-awareness, use of sensors, being executable on various mobile devices, limited hardware resources, etc. To this aim, in this...
Sagittal range of motion of the thoracic spine using standing digital radiography: A throughout comparison with non-radiographic data reviewed from the literature
, Article Scientia Iranica ; Volume 26, Issue 3B , 2019 , Pages 1307-1315 ; 10263098 (ISSN) ; Arjmand, N ; Sharif University of Technology
Sharif University of Technology
2019
Abstract
Previous studies have measured thoracic Range of Motion (RoM) using either skin-mounted devices or supine CT-imaging and have reported on quite different RoMs. Given the inherent shortcomings of measurements of vertebrae movements from the overlying skin, the present study aims to measure normal RoM of the thoracic spine in the sagittal plane using the upright digital radiography. Lateral radiographs of the thoracic spine were obtained from eight asymptomatic male subjects in upright standing and full forward flexion using a mobile U-arm digital radiographic system. Total (T1-T12), upper (T1-T6), and lower (T6-T12) thoracic RoMs were measured. A throughout comparison of available skin-based...
Localizing exception faults in Android applications
, Article Scientia Iranica ; Volume 26, Issue 3 D , 2019 , Pages 1567-1588 ; 10263098 (ISSN) ; Heydarnoori, A ; Sharif University of Technology
Sharif University of Technology
2019
Abstract
In software programs, most of the time, there is a chance for occurrence of faults in general, and exception faults in particular. Localizing those pieces of code that are responsible for a particular fault is one of the most complicated tasks, and it can produce incorrect results if done manually. Semi-automated and fully-automated techniques have been introduced to overcome this issue. However, despite recent advances in fault localization techniques, they are not necessarily applicable to Android applications because of their special characteristics such as context-awareness, use of sensors, being executable on various mobile devices, limited hardware resources, etc. To this aim, in this...
Sagittal range of motion of the thoracic spine using standing digital radiography: A throughout comparison with non-radiographic data reviewed from the literature
, Article Scientia Iranica ; Volume 26, Issue 3B , 2019 , Pages 1307-1315 ; 10263098 (ISSN) ; Arjmand, N ; Sharif University of Technology
Sharif University of Technology
2019
Abstract
Previous studies have measured thoracic Range of Motion (RoM) using either skin-mounted devices or supine CT-imaging and have reported on quite different RoMs. Given the inherent shortcomings of measurements of vertebrae movements from the overlying skin, the present study aims to measure normal RoM of the thoracic spine in the sagittal plane using the upright digital radiography. Lateral radiographs of the thoracic spine were obtained from eight asymptomatic male subjects in upright standing and full forward flexion using a mobile U-arm digital radiographic system. Total (T1-T12), upper (T1-T6), and lower (T6-T12) thoracic RoMs were measured. A throughout comparison of available skin-based...
A suction-controlled ring device to measure the coefficient of lateral soil pressure in unsaturated soils
, Article Geotechnical Testing Journal ; Volume 44, Issue 1 , 2020 ; Garakani, A. A ; Golshani, A ; Mirzaii, A ; Sharif University of Technology
ASTM International
2020
Abstract
A suction-controlled ring device has been developed to continuously measure the coefficient of lateral soil pressure in deformable unsaturated soil samples from the at-rest to the active condition under application of increasing vertical pressure and controlled matric suction. The device incorporates a thin aluminum specimen ring equipped with horizontal strain gages for recording the lateral soil strains. In addition, a sensor recording water volume changes is utilized to continuously monitor the degree of saturation of the soil sample during tests. The matric suction within the soil texture is controlled using the axis translation technique. In order to verify the performance of the ring...
A contourlet-based face detection method in color images
, Article 3rd IEEE International Conference on Signal Image Technologies and Internet Based Systems, SITIS'07, Jiangong Jinjiang, Shanghai, 16 December 2007 through 18 December 2007 ; 2007 , Pages 727-732 ; 9780769531229 (ISBN) ; Jamzad, M ; Sharif University of Technology
2007
Abstract
The first step of any face processing system is detecting the location in images where faces are present. In this paper we present an upright frontal face detection system based on the multi-resolution analysis of the face. In this method firstly, skin-color information is used to detect skin pixels in color images; then, the skin-region blocks are decomposed into frequency sub-bands using contourlet transform. Features extracted from sub-bands are used to detect face in each block. A multi-layer perceptrone (MLP) neural network was trained to do this classification. To decrease false positive detection we use eyes and lips template matching. These templates achieved by averaging...
Emerging OCDMA communication systems and data networks [Invited]
, Article Journal of Optical Networking ; Volume 6, Issue 9 , 2007 , Pages 1138-1178 ; 15365379 (ISSN) ; Sharif University of Technology
Optical Society of American (OSA)
2007
Abstract
I present an in-depth review of the trends and the directions taken by researchers worldwide in optical code-division multiple-access (OCDMA) systems. I highlight those trends and features that I believe are essential to the successful introduction of various OCDMA techniques in communication systems and data networks in the near future. In particular I begin by giving a comprehensive review of the construction of optical orthogonal codes (OOCs). Specifically I discuss the recently developed algorithms that are based on matrix algebra, which simplify and enhance the efficiencies of algorithms in OOC generation. In communication systems studies I first focus on and discuss various OCDMA...
Detection of a band-limited signal using an orthonormal, fully-decimated filter-bank
, Article Scientia Iranica ; Volume 14, Issue 6 , 2007 , Pages 555-565 ; 10263098 (ISSN) ; Tadaion, A. A ; Nayebi, M. M ; Aref, M. R ; Sharif University of Technology
Sharif University of Technology
2007
Abstract
In this paper, two methods are proposed for the detection of a band-limited signal in unknown variance white Gaussian noise. The complex amplitude and the frequency of the signal and the noise variance are assumed as unknown parameters. Using wavelet concepts, an orthonormal, fully-decimated filter-bank is employed to decompose the signal into its subband components. It is shown that, in this process, the noise is also decomposed into orthonormal zero-mean components. In the output, if a band-limited target signal is present, the respective single subband component (or two components in marginal cases) containing the target signal presents a non-zero mean. The presence of a non-zero mean...
Data acquisition and resistance measurements using a simple program
, Article Scientia Iranica ; Volume 14, Issue 5 , 2007 , Pages 467-473 ; 10263098 (ISSN) ; Azimi, P ; Poseh, G. H ; Sharif University of Technology
Sharif University of Technology
2007
Abstract
The goal of this paper is to describe a simple method for the automated data acquisition and analysis of data taken by programmable instruments. Device controls and communication method are explained and some typical illustrative examples showing the potential applications of the method in real experiments are presented. This method offers a quick and flexible way to control many instruments by using a multi-device arrangement of a stacking method in a parallel operation. The General-Purpose Interface Bus (GPIB) is used here for remote control of the devices. By using Excel and Visa interactive programs and using GPIB interface, easy communication and data transfer between instruments and a...
Turn-off chelation-enhanced fluorescence sensing of carbon dot-metallic deep eutectic solvent by imidazole-based small molecules
, Article Sensors and Actuators B: Chemical ; Volume 344 , 2021 ; 09254005 (ISSN) ; Bagheri, H ; Es-haghi, A ; Sharif University of Technology
Elsevier B.V
2021
Abstract
Low accuracy, requirement of expensive instruments, derivatization and multi-step sample preparation, inconsistencies during the fabrication process, time-consuming procedures and utilization of eco-unfriendly chemicals are some limitations of various developed methods for detection of 4-methylimidazol (4-MeI). Herein, a rapid and miniaturized fluorescent probe based on the ultrasound‒assisted formation of carbon dots (CDs) in a metallic deep eutectic solvent (MDES) was developed and conveniently implemented to detect 4-MeI in commercial dark soft drinks. In-situ synthesis of CDs-chelated metals in the presence of the target analyte facilitates a kinetically fluorescence emission with no...
Modeling vibrational behavior of silicon nanowires using accelerated molecular dynamics simulations
, Article Scientia Iranica ; Volume 27, Issue 2 , 2021 , Pages 819-827 ; 10263098 (ISSN) ; Delafrouz, P ; Sharif University of Technology
Sharif University of Technology
2021
Abstract
The classical methods utilized for modeling nano-scale systems are not practical because of the enlarged surface e ects that appear at small dimensions. Contrarily, implementing more accurate methods is followed by prolonged computations as these methods are highly dependent on quantum and atomistic models, and they can be employed for very small sizes in brief time periods. In order to speed up the Molecular Dynamics (MD) simulations of the silicon structures, Coarse-Graining (CG) models are put forward in this research. The procedure involves establishing a map between the main structure's atoms and the beads comprising the CG model and modifying the parameters of the system so that the...
Detection of geochemical anomalies using a fractal-wavelet model in Ipack area, Central Iran
, Article Journal of Geochemical Exploration ; Volume 220 , 2021 ; 03756742 (ISSN) ; Afzal, P ; Yasrebi, A. B ; Gholinejad, M ; Wetherelt, A ; Sharif University of Technology
Elsevier B.V
2021
Abstract
The purpose of this study is to detect geochemical anomalies utilizing a Wavelet-Number (W-N) fractal model based on combination of a two-dimensional Discrete Wavelet Transformation (DWT) signal analysis and a Concentration-Area (C-A) fractal modeling. The DWT was carried by Sym8 as a selected wavelet pattern (by energy matching method) for Zn and Pb based on rock samples collected from the Ipack area, Central Iran. In addition, the DWT was decomposed by continuous wavelet coefficients at five levels and a final image was synthesized. Furthermore, the DWT data were classified using a fractal-wavelet model for delineation of both Zn and Pb anomalies from background levels in this area....
Investigation of time-frequency analysis and transitional boundary layer over a pitching airfoil
, Article Scientia Iranica ; Volume 28, Issue 2 B , 2021 , Pages 860-876 ; 10263098 (ISSN) ; Soltani, M. R ; Maghrebi, M. J ; Sharif University of Technology
Sharif University of Technology
2021
Abstract
Transitional boundary layer over a pitching airfoil at low Reynolds number (Re = 2:7 × 105) is experimentally investigated using space-frequency and time-frequency analyses of hot- film signals. Boundary layer events are visualized based on the space-frequency and time-frequency plots. The precursor phenomenon for turbulent and fully separated flows is presented based on the time-frequency analysis. A new technique based on time-frequency analysis of hot- film signals is introduced to measure the transition onset and relaminarization locations. This technique functions based on the analysis of high-frequency disturbances of the measured data. Significant attention has been drawn to the...
Investigation of time-frequency analysis and transitional boundary layer over a pitching airfoil
, Article Scientia Iranica ; Volume 28, Issue 2 B , 2021 , Pages 860-876 ; 10263098 (ISSN) ; Soltani, M. R ; Maghrebi, M. J ; Sharif University of Technology
Sharif University of Technology
2021
Abstract
Transitional boundary layer over a pitching airfoil at low Reynolds number (Re = 2:7 × 105) is experimentally investigated using space-frequency and time-frequency analyses of hot- film signals. Boundary layer events are visualized based on the space-frequency and time-frequency plots. The precursor phenomenon for turbulent and fully separated flows is presented based on the time-frequency analysis. A new technique based on time-frequency analysis of hot- film signals is introduced to measure the transition onset and relaminarization locations. This technique functions based on the analysis of high-frequency disturbances of the measured data. Significant attention has been drawn to the...
Phase II monitoring of generalized linear profiles under different types of changes
, Article Scientia Iranica ; Volume 28, Issue 1 E , 2021 , Pages 557-571 ; 10263098 (ISSN) ; Mahlooji, H ; Sharif University of Technology
Sharif University of Technology
2021
Abstract
Various control charts have been proposed to monitor generalized linear pro les in Phase II. However, the robustness of the proposed methods in detecting di erent types and especially di erent directions of changes is not well-studied in the literature. In real-world applications, di erent kinds of change such as drift and multiple changes are likely to occur, which can be isotonic (increasing) or antitonic (decreasing). This paper studies the robustness of the Rao Score Test (RST) method, T2, and Multivariate Exponential Weighted Moving Average (MEWMA) in di erent types, drift and multiple, and directions of changes. The RST method also bene ts from a change-point detection approach whose...