Sharif Digital Repository

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... 

Because of opportunistic spectrum access, cognitive radio networks is a promising solution for spectrum scarcity problem. In cognitive radio networks, users need to communicate through control channels in order to cooperate for sharing sensing information, channel sharing and spectrum management. As a result control channels security is of a great importance. If control channels get jammed, network's performance degrades dramatically; therefore, the jammers primary target in cognitive radio networks is to demolish control channels in order to disturb the network's performance. Traditionally hopping sequences were used to battle this problem but considering cognitive radio networks... 

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... 

In this article, we use an efficient analytical method called homotopy analysis method (HAM) to derive an approximate solution of nonlinear ion sound waves equation. Actually, we solved Korteweg-de Vries equation arises in a one-dimensional macroscopic plasma model describing the weakly nonlinear evolution of ion sound speed by the HAM. Unlike the perturbation method, the HAM does not require the addition of a small physically parameter to the differential equation. It is applica-ble to strongly and weakly nonlinear problems. Moreover, the HAM involves an auxiliary parameter, which renders the convergence param-eter of series solutions controllable, and increases the convergence, and... 

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... 

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... 

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...