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najafzadeh--ayda
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3D Multi Target Tracking
, M.Sc. Thesis Sharif University of Technology ; Kasaei, Shohreh (Supervisor)
Abstract
The purpose of multi target tracking, is tracking multiple target in each frame of video sequences simultaneously. Object tracking encounters many challenges. Two major challenges of tracking problem that we focus on in them in this thesis are detecting object in each frame of video sequence and handling occlusion problem. Our proposed method for multi target tracking considers one target as a main target and other targets as subsidiary targets. Proposed method track objects in initial view by Kalman filter that is adapted and tuned for multi target tracking. In case of occlusion our method uses data from auxiliary view for handling occlusion. In auxiliary view objects that are occluded in...
Multiple soccer players tracking
, Article Proceedings of the International Symposium on Artificial Intelligence and Signal Processing, AISP 2015, 3 March 2015 through 5 March 2015 ; March , 2015 , Pages 310-315 ; 9781479988174 (ISBN) ; Fotouhi, M ; Kasaei, S ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2015
Abstract
This paper, describes a solution for tracking multiple soccer players, simultaneously, in soccer ground. It adapts Kalman filter for tracking multiple players. Adapting Kalman filter is divided to four main tasks. The first task is defining the state vector for multiple object tracking. The second task is determining a motion model for estimating the position of soccer players in the next frame. The third task is defining an observation method for detecting soccer players in each frame. Finally, the fourth task is tuning the measurement noise covariance and estimating noise covariance. In the third task, a novel observation method for detecting soccer players is proposed. This method divides...
Entanglement Hamiltonian of Interacting Systems and its Applications in the Study of Strongly Correlated Systems
, M.Sc. Thesis Sharif University of Technology ; Vaezi, Mir Abolhassan (Supervisor)
Abstract
Recent advances in numerical computations in the field of strongly correlated systems have provided us to calculate the entanglement spectrum and the entanglement entropy for interacting systems. Calculating the explicit form of the entanglement Hamiltonian (a.k.a. the modular Hamiltonian) is considered as a difficult problem.In this dissertation, we intend to introduce a method and by means of the d ensity-matrix-renormalization-group algorithm to obtain for the first time the second quantization form of the entanglement Hamiltonian of interacting systems at zero temperature. We implement our method for one-dimensional Heisenberg spin chain and also Heisenberg model on a square lattice...
Anti-aggregation of gold nanoparticles for metal ion discrimination: a promising strategy to design colorimetric sensor arrays
, Article Sensors and Actuators, B: Chemical ; Volume 270 , 2018 , Pages 545-551 ; 09254005 (ISSN) ; Ghasemi, F ; Hormozi Nezhad, M. R ; Sharif University of Technology
2018
Abstract
The first report of anti-aggregation-based sensor arrays is presented. The strategy is based on the competitive interaction of citrate-capped gold nanoparticles (AuNPs) and heavy metal ions (i.e., Hg(II), Ag(I), Fe(III), and Pb(II)) with three aggregation reagents (i.e., cysteine, melamine, and arginine). In the presence of aggregation reagent, the color and UV–vis spectra of AuNPs are changed indicating the aggregation of AuNPs. Addition of the aggregation reagents which are firstly treated with the ions, causes AuNPs turn from the aggregation to the dispersion state. The anti-aggregation capability of ions towards various aggregation reagents is different because of distinct stability...
Design of an Optoelectronic Tongue Based on Anti-Aggregation of Gold Nanoparticles for Detection and Classification of Heavy Metal Ions
, M.Sc. Thesis Sharif University of Technology ; Hormozi-Nezhad, Mohammad Reza (Supervisor)
Abstract
The first report of anti-aggregation-based sensor arrays is presented. The strategy is based on the competitive interaction of citrate-capped gold nanoparticles (AuNPs) and heavy metal ions (i.e., Hg(II), Ag(I), Fe(III), and Pb (II)) with three aggregation reagents (i.e., cysteine, melamine, and arginine). In the presence of aggregation reagent,the color and UV–vis spectra of AuNPs are changed indicating the aggregation ofAuNPs. Addition of the aggregation reagents which are firstly treated with the ions, causes AuNPs turn from the aggregation to the dispersion state. The anti-aggregation capability of ions towards various aggregation reagents is different because of distinct stability...
A Study of Laboratory Proposals for Detecting Gravitational Entanglement in Quantum Interferometry
, M.Sc. Thesis Sharif University of Technology ; Khosravi, Nima (Supervisor) ; Karimipour, Vahid (Supervisor)
Abstract
In recent years, growing attention has been directed toward the possibility of testing the quantum nature of gravity using laboratory-scale systems; a pursuit motivated by the fundamental question of whether the gravitational field, like the other fundamental interactions, possesses quantum degrees of freedom or can be fully described by a classical theory. In this thesis, we begin by reviewing the principles of quantum interference and the role of path-dependent phase in experiments such as atomic interferometry and the gravitational Aharonov–Bohm effect, illustrating how these techniques enable the detection of extremely weak gravitational influences. We then introduce quantum entanglement...
Benchmarking of Monte Carlo model of Siemens Oncor® linear accelerator for 18MV photon beam: determination of initial electron beam parameters
, Article Journal of X-Ray Science and Technology ; Volume 27, Issue 6 , 2 January , 2020 , Pages 1047-1070 ; Hoseini Ghafarokhi, M ; Bolagh, R. S. M ; Haghparast, M ; Zarifi, S ; Nickfarjam, A ; Farhood, B ; Chow, J. C. L ; Sharif University of Technology
IOS Press
2020
Abstract
OBJECTIVE: This study aims to benchmark a Monte Carlo (MC) model of the 18 MV photon beam produced by the Siemens Oncor® linac using the BEAMnrc and DOSXYZnrc codes. METHODS: By matching the percentage depth doses and beam profiles calculated by MC simulations with measurements, the initial electron beam parameters including electron energy, full width at half maximum (spatial FWHM), and mean angular spread were derived for the 10×10 cm2 and 20×20 cm2 field sizes. The MC model of the 18 MV photon beam was then validated against the measurements for different field sizes (5×5, 30×30 and 40×40 cm2) by gamma index analysis. RESULTS: The optimum values for electron energy, spatial FWHM and mean...
Diabetes-associated thigh muscle degeneration mediates knee osteoarthritis–related outcomes: results from a longitudinal cohort study
, Article European Radiology ; Volume 33, Issue 1 , 2023 , Pages 595-605 ; 09387994 (ISSN) ; Moradi, K ; Guermazi, A ; Dolatshahi, M ; Zikria, B ; Najafzadeh, N ; Kalyani, R. R ; Roemer, F. W ; Berenbaum, F ; Demehri, S ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH
2023
Abstract
Objectives: We examined the association between diabetes mellitus (DM) and longitudinal MRI biomarkers for thigh muscle degeneration in patients with knee osteoarthritis (KOA) and their mediatory role in worsening KOA-related symptoms. Methods: The Osteoarthritis Initiative (OAI) participants with radiographic KOA (Kellgren-Lawrence grade ≥ 2) were included. Thighs and corresponding knees of KOA patients with versus without self-reported DM were matched for potential confounders using propensity score (PS) matching. We developed and used a validated deep learning method for longitudinal thigh segmentation. We assessed the association of DM with 4-year longitudinal muscle degeneration in...
Role of Thigh Muscle Changes in Knee Osteoarthritis Outcomes: Osteoarthritis Initiative Data
, Article Radiology ; Volume 305, Issue 1 , 2022 , Pages 169-178 ; 00338419 (ISSN) ; Dolatshahi, M ; Moradi, K ; Najafzadeh, N ; Eng, J ; Zikria, B ; Wan, M ; Cao, X ; Roemer, F. W ; Guermazi, A ; Demehri, S ; Sharif University of Technology
Radiological Society of North America Inc
2022
Abstract
Background: Longitudinal data on the association of quantitative thigh muscle MRI markers with knee osteoarthritis (KOA) outcomes are scarce. These associations are of clinical importance, with potential use for thigh muscle–directed disease-modifying interventions. Purpose: To measure KOA-associated longitudinal changes in MRI-derived muscle cross-sectional area (CSA) and adipose tissue and their association with downstream symptom worsening and knee replacement (KR). Materials and Methods: In a secondary analysis of the Osteoarthritis Initiative multicenter prospective cohort (February 2004 through October 2015), knees of participants with available good-quality thigh MRI scans at baseline...