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Element free galerkin mesh-less method for fully coupled analysis of a consolidation process
, Article Scientia Iranica ; Volume 16, Issue 1 A , 2009 , Pages 65-77 ; 10263098 (ISSN) ; Pak, A ; Sharif University of Technology
2009
Abstract
A formulation of the Element Free Galerkin (EFG), one of the mesh-less methods, is developed for solving coupled problems and its validity for application to soil-water problems is examined through numerical analysis. The numerical approach is constructed to solve, two governing partial differential equations of equilibrium and the. continuity of pore water, simultaneously. Spatial variables in a weak form, the displacement increment and excess pore, water pressure increment, are discretized using the same EFG shape functions. An incremental constrained Galerkin weak form is used to create the discrete system equations and a fully implicit scheme is used to create the discretization of the...
A Model for Temperature Distribution Prediction of a Non-Newtonian Fluid in an Agitated Vessel by CFD Method
, M.Sc. Thesis Sharif University of Technology ; Farhadi, Fathollah (Supervisor)
Abstract
In this thesis heat transfer coefficient and temperature distribution of two Non-Newtonian and a Newtonian fluids in stirred vessel are investigated using Computational Fluid Dynamic (CFD). This vessel is agitated with new impeller called MAXBLEND. Non-Newtonian fluids are aqueous solutions of carboxymethyl cellulose 1.5%w/w and xanthan gum 3% w/w and Newtonian fluid is glycerin. This vessel is simulated in laminar regime with Reynolds number less than 14. The results of simulation are compared with correlation proposed by Kawase et al. Furthermore as a new research for this impeller, the effects of vessel diameter and position of impeller in the vessel on heat transfer coefficient are...
Analyzing the Interplay of Power Management and Communication Reliability of Wireless Networks in Embedded Applications
, M.Sc. Thesis Sharif University of Technology ; Ejlali, Alireza (Supervisor)
Abstract
Due to safety critical applications of the embedded systems, reliability is one of the most important properties of these systems. Wireless networks also have error prone data transmission channels and limited power consumption. Therefore reliability and power conservation are two vital characteristics of the wireless network especially in embedded applications. Since achieving to a desirable level of data reliability is power consuming, we must consider a trade-off between power consumption and data reliability. In wireless networks power consumption can be categorized into: power consumption in wireless devices and power consumption in data transmission. For decrement of wireless devices...
Sum of all shortest Path in Undirected Unweighted Planar Graphs
, M.Sc. Thesis Sharif University of Technology ; Ghodsi, Mohammad (Supervisor)
Abstract
Computing the sum of all-pairs shortest paths is a fundamental problem in graph theory with applications in chemistry, network analysis, and more. The Wiener index of a graph is defined as the sum of shortest path distances over all unordered pairs of vertices. It was first introduced by Harry Wiener in 1947. Let (\ G\ ) be a planar graph. The distance between two vertices (\ x,\ y\ \in\ V\left(G\right)), denoted by (\ d_{G\left(x,\ y\right)}), is defined as the length of a shortest path between (\ x\ ) and (\ y\ )\ in (\ G\ ), if such a path exists; otherwise, (\ d_{G\left(x,\ y\right)}=\ \infty). The Wiener index of (\ G\ ), denoted by (\mathcal{W}\left(G\right)), is given by:...
Confidential Access to the Outsourced Relational Data
, M.Sc. Thesis Sharif University of Technology ; Jalili, Rasool (Supervisor)
Abstract
In recent years, there has been a trend toward outsourcing data to the cloud provider. These companies must tackle the data security challenges. Generally these parties are assumed to be honest but curious. In past years, the research communities have been investigating different solution to ensure confidentiality.
In addition to data confidentiality access and pattern confidentiality is a high-priority issue in some cases so. potential adversary should be unable to drive information from the observed access pattern to the outsourced data. Despite the fact that there are more investigation in the field of data confidentiality, concern over data security are the rise in outsourcing data,...
In addition to data confidentiality access and pattern confidentiality is a high-priority issue in some cases so. potential adversary should be unable to drive information from the observed access pattern to the outsourced data. Despite the fact that there are more investigation in the field of data confidentiality, concern over data security are the rise in outsourcing data,...
A coupled hydro-mechanical analysis for prediction of hydraulic fracture propagation in saturated porous media using EFG mesh-less method
, Article Computers and Geotechnics ; Vol. 55, issue , January , 2014 , p. 254-266 ; Pak, A ; Soga, K ; Sharif University of Technology
2014
Abstract
The details of the Element Free Galerkin (EFG) method are presented with the method being applied to a study on hydraulic fracturing initiation and propagation process in a saturated porous medium using coupled hydro-mechanical numerical modelling. In this EFG method, interpolation (approximation) is based on nodes without using elements and hence an arbitrary discrete fracture path can be modelled.The numerical approach is based upon solving two governing partial differential equations of equilibrium and continuity of pore water simultaneously. Displacement increment and pore water pressure increment are discretized using the same EFG shape functions. An incremental constrained Galerkin...
Some numerical issues using element-free galerkin mesh-less method for coupled hydro-mechanical problems
, Article International Journal for Numerical and Analytical Methods in Geomechanics ; Volume 33, Issue 7 , 2009 , Pages 915-938 ; 03639061 (ISSN) ; Soga, K ; Pak, A ; Sharif University of Technology
2009
Abstract
A new formulation of the element-free Galerkin (EFG) method is developed for solving coupled hydromechanical problems. The numerical approach is based on solving the two governing partial differential equations of equilibrium and continuity of pore water simultaneously. Spatial variables in the weak form, i.e. displacement increment and pore water pressure increment, are discretized using the same EFG shape functions. An incremental constrained Galerkin weak form is used to create the discrete system equations and a fully implicit scheme is used for discretization in the time domain. Implementation of essential boundary conditions is based on a penalty method. Numerical stability of the...
Centrality-based group formation in group recommender systems
, Article 26th International World Wide Web Conference, WWW 2017 Companion, 3 April 2017 through 7 April 2017 ; 2019 , Pages 1187-1196 ; 9781450349147 (ISBN) ; Khalili, S ; Elahe Ghalebi, K ; Grosu, R ; Mojde Morshedi, S ; Movaghar, A ; Sharif University of Technology
International World Wide Web Conferences Steering Committee
2019
Abstract
Recommender Systems have become an attractive field within the recent decade because they facilitate users' selection process within limited time. Conventional recommender systems have proposed numerous methods focusing on recommendations to individual users. Recently, due to a significant increase in the number of users, studies in this field have shifted to properly identify groups of people with similar preferences and provide a list of recommendations for each group. Offering a recommendations list to each individual requires significant computational cost and it is therefore often not efficient. So far, most of the studies impose four restrictive assumptions: (1) limited number of...
Investigate Laboratory Production of Hydroxyurea
, M.Sc. Thesis Sharif University of Technology ; Bastani, Dariush (Supervisor) ; Seifkordi, Ali Akbar (Supervisor) ; Zegordi, Elahe (Co-Advisor)
Abstract
Hydroxyurea is an anticancer drug that is commonly used to treat chronic myeloid leukemia (white blood cell cancer in bone marrow), polycythemia vera (red blood cell cancer), sickle cell anemia, solid tumors, and in particular leukemia. In this research, in addition to analyzing all available methods for synthesis of hydroxyurea, the most economical method for synthesis of hydroxyurea which is Hantzsch method was chosen; then we synthesized hydroxyurea crystals using a precipitation or crystallization process. To do so, two hydroxylamine hydrochloride and potassium cyanate reactants have been used in the semi batch reactor. Since the reaction efficiency and purity of the synthesized...