Loading...
Search for:
lahe-motlagh--peyman
0.1 seconds
Modeling and Sensitivity Analysis of Heavy Vehicles Tire With Target of Determining Stiffness and Damping Characteristics
, M.Sc. Thesis Sharif University of Technology ; Saadat Foumani, Mahmoud (Supervisor) ; Fallah Rajabzadeh, Famida (Supervisor)
Abstract
Tire is one component of the suspension system and has beneficial effects on reducing vibrations caused to the vehicle. This study aims to determine the factors affecting the damping and stiffness of the tire is carried out. The modeling of factors were identified. For testing the modeling effort is to be made to the instruments used to measure the damping and stiffness of the tires. To make the structural static analysis, dynamic and modal was to have sufficient structural strength and the displacements and stresses are sensibly placed. Factors that have influence on the hardness of the ring diameter, the outer diameter of the tire, tire pressure, tire tread depth, tire wall thickness,...
A Realistic Urban Mobility Model for Mobile Ad Hoc Network
, M.Sc. Thesis Sharif University of Technology ; Manzuri, Mohammad Taghi (Supervisor)
Abstract
A Mobile Ad hoc NETwork (MANET) is a set of wireless mobile nodes that form a self configured network. MANETs do not have infrastructure and are not currently deployed on large scales. So research in this area is simulation based. Mobility model in a mobile ad hoc network explains the movement pattern of mobile users and is designed to describe the change of their location, velocity and acceleration over time. One of the challenges in this field is the definition of a common mobility model that provides an accurate and realistic movement description of mobile nodes. In this thesis we want to study the mobility pattern of vehicles on Kish Island and compare it with different kinds of...
Performance Ehancement of Congestion Control Algorithm Through Traffic Flow Istinction
, M.Sc. Thesis Sharif University of Technology ; Jahangir, Amir Hossein (Supervisor)
Abstract
Congestion is an important issue in the network environment. To keep stable the perfor-mance of the network, congestion control algorithms have been extensively studied. Queue management method employed by the routers is one of the important issues in the congestion control study. Active Queue Management (AQM) has been proposed for early detection of congestion inside the network. AQM mechanisms control the queue length in a router by dropping arriving packets. The Random Early Detection (RED) is the most popular AQM mechanism used in routers on the Intenet to allow network users to simultaneously achieve high throughput and low average delay. The RED algorithm may cause heavy oscillation of...
Calculating Runoff Coefficient of Urmia Lake Basin by Empirical Models and Remot Sensing (RS) Technology
, M.Sc. Thesis Sharif University of Technology ; Tajrishy, Masoud (Supervisor) ; Arasteh, Peyman (Co-Advisor)
Abstract
Estimation of runoff in the ungauged basins is a challenge for hydrologists. The main objective of this research is to produce runoff coefficient map using SCS-CN (1972) and Kennessey (1930) as empirical models to for Urmia Lake basin between for 2006-2011.Both SCS-CN and Kennessey methods use slope, land use, and soil permeability data to estimate surface runoff. Accuracy of each model is tested along with the observed runoff using the Root Mean Square Error (RMSE).Urmia Lake basin includes about 400,000 hectares irrigated land, which constitutes around 10 percent of the entire basin area. To exclude the anthropological activities from the estimations, methods were applied only for 28...
A note on isometries of Lipschitz spaces
, Article Journal of Mathematical Analysis and Applications ; Vol. 411, Issue. 2 , 2014 , Pages 555-558 ; ISSN: 0022247X ; Sharif University of Technology
2014
Abstract
The main purpose of this article is to generalize a recent result about isometries of Lipschitz spaces. Botelho, Fleming and Jamison [2] described surjective linear isometries between vector-valued Lipschitz spaces under certain conditions. In this article, we extend the main result of [2] by removing the quasi-sub-reflexivity condition from Banach spaces
An integral type characterization of constant functions on metric-measure spaces
, Article Journal of Mathematical Analysis and Applications ; Volume 385, Issue 1 , January , 2012 , Pages 194-201 ; 0022247X (ISSN) ; Sharif University of Technology
2012
Abstract
The main purpose of this article is to generalize a characterization of constant functions to the context of metric-measure spaces. In fact, we approximate a measurable function, in terms of a certain integrability condition, by Lipschitz functions. Then, similar to Brezis (2002) [2], we establish a necessary and sufficient condition in order that any measurable function which satisfies an integrability condition to be constant a.e. Also, we provide a different proof for the main result of Pietruska-Pałuba (2004) [7] in the setting of Dirichlet forms
Generalized rademacher-stepanov type theorem and applications
, Article Zeitschrift fur Analysis und ihre Anwendung ; Volume 28, Issue 3 , 2009 , Pages 249-275 ; 02322064 (ISSN) ; Sharif University of Technology
2009
Abstract
The main purpose of this article is to generalize a theorem of Stepanov which provides a necessary and sufficient condition for almost everywhere differentiability of functions over Euclidean spaces. We state and prove an Lp-type generalization of the Stepanov theorem and then we extend it to the context of Orlicz spaces. Then, this generalized Rademacher-Stepanov type theorem is applied to the Sobolev and bounded variation maps with values into a metric space. It is shown that several generalized differentiability type theorems are valid for the Sobolev maps from a Lipschitz manifold into a metric space. As a byproduct, it is shown that the Sobolev spaces of Korevaar-Schoen and Reshetnyak...
A non-existence theorem for isometric immersions
, Article Journal of Geometry and Physics ; Volume 59, Issue 3 , 2009 , Pages 263-266 ; 03930440 (ISSN) ; Sharif University of Technology
2009
Abstract
Let f : M {long rightwards arrow} over(M, -) be an isometric immersion between Riemannian manifolds. For certain conditions on M and over(M, -) in terms of curvatures and external diameter, we extend the non-embedding theorem of Chern and Kuiper to the isometric immersions of non-compact manifolds. Also, our results generalize and improve the main results of Jorge and Koutroufiotis [L. Jorge, D. Koutroufiotis, An estimate for the curvature of bounded submanifolds, Amer. J. Math. 103 (4) (1981) 711-725] and Veeravalli [A. R. Veeravalli, A sharp lower bound for the Ricci curvature of bounded hypersurfaces in space forms, Bull. Austral. Math. Soc. 62 (1) (2000) 165-170]. © 2008 Elsevier B.V....
An integral type characterization of lipschitz functions over metric-measure spaces
, Article Journal of Mathematical Analysis and Applications ; Volume 479, Issue 2 , 2019 , Pages 1708-1714 ; 0022247X (ISSN) ; Sharif University of Technology
Academic Press Inc
2019
Abstract
The main purpose of this article is to generalize a characterization of Lipschitz functions in the context of metric-measure spaces. The results are established in the class of metric-measure spaces which satisfy a strong version of the doubling (Bishop-Gromov regularity) condition. Indeed, we establish a necessary and sufficient condition in order that any measurable function which satisfies an integrability condition to be essentially Lipschitzian. © 2019 Elsevier Inc
Isometries of Lipschitz type function spaces
, Article Mathematische Nachrichten ; Volume 291, Issue 11-12 , 2018 , Pages 1899-1907 ; 0025584X (ISSN) ; Sharif University of Technology
Wiley-VCH Verlag
2018
Abstract
In this article, we describe isometries over the Lipschitz spaces under certain conditions. Indeed, we provide a unified proof for the main results of and in a more general setting. Finally, we extend our results for some other functions spaces like the space of vector-valued little Lipschitz maps and pointwise Lipschitz maps. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
A remark on the bourgain-brezis-mironescu characterization of constant functions
, Article Houston Journal of Mathematics ; Volume 46, Issue 1 , 2020 , Pages 113-115 ; Sharif University of Technology
University of Houston
2020
Abstract
The purpose of this paper is to describe a simple proof for a result originally presented by H. Brezis in [B], with roots in J. Bourgain, H. Brezis and P. Mironescu [BBM]. © 2020 University of Houston
A remark on isometries of absolutely continuous spaces
, Article Journal of Function Spaces ; Volume 2020 , 2020 ; Sharif University of Technology
Hindawi Limited
2020
Abstract
The purpose of this article is to study the isometries between vector-valued absolutely continuous function spaces, over compact subsets of the real line. Indeed, under certain conditions, it is shown that such isometries can be represented as a weighted composition operator. © 2020 Alireza Ranjbar-Motlagh
Generalizations of the Liouville theorem
, Article Differential Geometry and its Application ; Volume 26, Issue 3 , 2008 , Pages 339-345 ; 09262245 (ISSN) ; Sharif University of Technology
2008
Abstract
The purpose of this paper is to generalize the Liouville theorem for functions which are defined on the complete Riemannian manifolds. Then, we apply it to the isometric immersions between complete Riemannian manifolds in order to obtain an estimate for the size of the image of immersions in terms of the supremum of the length of their mean curvature vector in a quite general setting. The proofs are based on the Calabi's generalization of maximum principle for functions which are not necessarily differentiable. © 2007 Elsevier B.V. All rights reserved
Isometries between spaces of vector-valued differentiable functions
, Article Journal of Function Spaces ; Volume 2021 , 2021 ; 23148896 (ISSN) ; Sharif University of Technology
Hindawi Limited
2021
Abstract
This article characterizes the isometries between spaces of all differentiable functions from a compact interval of the real line into a strictly convex Banach space. © 2021 Alireza Ranjbar-Motlagh
A note on the Poincaré inequality
, Article Studia Mathematica ; Volume 154, Issue 1 , 2003 , Pages 1-11 ; 00393223 (ISSN) ; Sharif University of Technology
Instytut Matematyczny
2003
Abstract
The Poincaré inequality is extended to uniformly doubling metric-measure spaces which satisfy a version of the triangle comparison property. The proof is based on a generalization of the change of variables formula
Besov type function spaces defined on metric-measure spaces
, Article Journal of Mathematical Analysis and Applications ; Volume 505, Issue 2 , 2022 ; 0022247X (ISSN) ; Sharif University of Technology
Academic Press Inc
2022
Abstract
The purpose of this article is to study the Besov type function spaces for maps which are defined on abstract metric-measure spaces. We extend some of the embedding theorems of the classical Besov spaces to the setting of abstract spaces. © 2021 Elsevier Inc
Poincaré inequality for abstract spaces
, Article Bulletin of the Australian Mathematical Society ; Volume 71, Issue 2 , 2005 , Pages 193-204 ; 00049727 (ISSN) ; Sharif University of Technology
Australian Mathematical Publishing Association
2005
Abstract
The Poincaré inequality is generalised to metric-measure spaces which support a strong version of the doubling condition. This generalises the Poincaré inequality for manifolds whose Ricci curvature is bounded from below and metric-measure spaces which satisfy the measure contraction property. Copyright Clearance Centre, Inc
Synthesis and analysis of the properties of ferro-fluids
, Article ICONN 2010 - Proceedings of the 2010 International Conference on Nanoscience and Nanotechnology, 22 February 2010 through 26 February 2010, Sydney, NSW ; 2010 , Pages 91-93 ; 9781424452620 (ISBN) ; Ghane Motlagh, B ; Ghane Golmohamadi, F ; Ghane Motlagh, R ; Rouhani, S ; Sharif University of Technology
2010
Abstract
We report the rheological properties of ferro-fluid (FF) containing iron oxide nano-particles. At first, a FF was synthesized by using chemical co-precipitaton[1]. The microstructure study using SEM revealed that the FF contained nano-particles with the mean particle size of 35nm. The XRD study revealed that we have well crystallized structures of magnetite; they appeared to be approximately single crystalline structures. The rheological results proved that the FF has non Newtonian behavior, it is a shear thinning fluid in all magnetic fields, Moreover, the magnetic field increases the viscosity in a definite shear rate due to the nano-particles agglomerations and formation of chain-like...
On harmonic maps from stochastically complete manifolds
, Article Archiv der Mathematik ; Volume 92, Issue 6 , 2009 , Pages 637-644 ; 0003889X (ISSN) ; Sharif University of Technology
2009
Abstract
The main purpose of this article is to generalize a theorem about the size of minimal submanifolds in Euclidean spaces. In fact, we state and prove a non-existence theorem about harmonic maps from a stochastically complete manifold into a cone type domain. The proof is based on a generalized version of the maximum principle applied to the Lapalace-Beltrami operator on Riemannian manifolds. © 2009 Birkhäuser Verlag Basel/Switzerland
Hydrodynamic Interactions of Artificial Reef using a Laboratory Model
,
M.Sc. Thesis
Sharif University of Technology
;
Borghei, Mahmoud
(Supervisor)
;
Aghtouman, Peyman
(Supervisor)
Abstract
Resources management is essential duo to sustainable development and marine resources limitations. There are several ways to restore coastal damaged ecosystems, one of the best and most cost effective solution is establishment of artificial reefs. A popular type of artificial reef is named Reef ball, a hollow hemisphere. In some regions these habitats has also been used as submerged breakwater. These structures recover and protect endangered species ecosystem although they provide aesthetic view to a beach. Main application of these structures is to provide a safe environment for marine creature. In this study initially Transmission coefficient variation in two-dimensional model experiments...