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Badge-based User Behavior Analysis in Social Media
, M.Sc. Thesis Sharif University of Technology ; Rabiee, Hamid Reza (Supervisor)
Abstract
As human societies develop and get more complex, the trend of social media changes to satisfy the more specialized needs of its users. Community-based Question and Answering sites are examples of very successful cases of those social media which respond to users’ pecialized needs. The survival of these Community-based Question and Answering sites do heavily depends on the voluntary contributions of their users. Hence, many of these Community-based Question and Answering sites apply gamification tools such as badges, points and reputation to prevent users’ churn and also to incentive new comers to participate in site-activities. The main purpose of this research is to investigate if the...
A hybrid model for simulation of fluid-structure interaction in water entry problems
, Article Physics of Fluids ; Volume 33, Issue 1 , 2021 ; 10706631 (ISSN) ; Rahbar Ranji, A ; Haddadpour, H ; Moghadas, H ; Sharif University of Technology
American Institute of Physics Inc
2021
Abstract
A hydroelastic hybrid model is developed to simulate the fluid-structure interaction in water entry problems using the partitioned approach. The interactions between a flat plate and the water are modeled by a hydroelastic model using explicit and implicit couplings. Both couplings are unstable due to numerical instability associated with the fluid added mass. To overcome the instability, an extended Wagner's model is combined with the hydroelastic model, and a hybrid model is developed. The extended Wagner's model is the extension of the classical Wagner's model that is used to estimate the fluid inertial, damping, and restoring forces of a flexible plate within the potential flow theory....
Hydro-aerodynamic mathematical model and multi-objective optimization of wing-in-ground effect craft in take-off
, Article Proceedings of the Institution of Mechanical Engineers Part M: Journal of Engineering for the Maritime Environment ; Volume 232, Issue 4 , 2018 , Pages 421-433 ; 14750902 (ISSN) ; Seif, M. S ; Sharif University of Technology
SAGE Publications Ltd
2018
Abstract
Hydro-aerodynamic mathematical model and multi-objective optimization of a popular wing-in-ground effect craft are presented in this research using a hydro-aerodynamic practical method and the genetic algorithm. The primary components of the wing-in-ground effect craft configuration include a compound wing, catamaran hull form and a power-augmented ram platform. The hydro-aerodynamic practical method with low computational time and high accuracy is performed by coupling hydrodynamic and aerodynamic considerations using the potential flow theory in ground effect and the semi-empirical equations proposed for high-speed marine vehicles. The trade-off between hydrodynamic and aerodynamic...
An additive theory for finite elastic-plastic deformations of the micropolar continuous media
, Article Acta Mechanica ; Volume 206, Issue 1-2 , 2009 , Pages 81-93 ; 00015970 (ISSN) ; Naghdabadi, R ; Sohrabpour, S ; Sharif University of Technology
2009
Abstract
In this paper, the method of additive plasticity at finite deformations is generalized to the micropolar continuous media. It is shown that the non-symmetric rate of deformation tensor and gradient of gyration vector could be decomposed into elastic and plastic parts. For the finite elastic deformation, themicropolar hypo-elastic constitutive equations for isotropicmicropolar materials are considered.Concerning the additive decomposition and the micropolar hypo-elasticity as the basic tools, an elastic-plastic formulation consisting of an arbitrary number of internal variables and arbitrary form of plastic flow rule is derived. The localization conditions for the micropolar material obeying...