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karamzadeh-motlagh--armin
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Structure Learning From Distributed Noisy Data
, M.Sc. Thesis Sharif University of Technology ; Motahari, Abolfazl (Supervisor) ; Manzuri Shalmani, Mohammad Taghi (Co-Supervisor)
Abstract
Probabilistic graphical models have great applications in studying and analyzing realworld data. For instance, these models have been used in reconstructing gene regularity networks. Specifically, learning the edges’ structure of graphical models is of great importance.Knowledge about the underlying structure of a graphical model brings about a valuable framework for the decomposition of the model’s distribution and reveals important information such as dependency among dimensions of samples, etc. Most existing methods for structure learning obtain the underlying structure of the model in a centralized fashion and without considering noise in data. In many applications, data exist in a...
Post-disaster Resilience of Transportation Network using Route Diversity Factor
, M.Sc. Thesis Sharif University of Technology ; Nasiri, Habibollah (Supervisor)
Abstract
Natural hazards such as earthquake take many lives each year and cause significant damages to infrastructures such as transportation networks. Whether after occurrence of a natural disaster like storm in order to evacuate, or after an abrupt event such as earthquake in order to provide emergency measures, a transportation network should maintain its functionality and performance in an acceptable degree and should recover in an effectively short period of time. In this study, the link or the set of links which their removal causes significant damage to the transportation network are identified. A specific index (N-Q index) has been used to describe the performance of the network. In addition,...
Optimization of Heat Recovery and Water Capture System from Boiler Flue Gas
, M.Sc. Thesis Sharif University of Technology ; Saboohi, Yadollah (Supervisor)
Abstract
Thermal energy and water in flue gases varies with the type of fuel and thermal conversion system. Flue gas temperature is maintained in the range of 140 (℃) to 200 (℃) and it is subject to the sulfur content of the fuel. Vapor content of the flue gas is in the range of 10%_20% of volumetric flow. Considerable part of vapor may be recovered which can be used as cooling water make up. There are various means and methods for water capture and heat recovery which includes shell-tube heat exchanger among others. Selection of appropriate material and heat exchanger is conditioned by corrosion, temperature of flue gas and it’s economic feasibility. Identification of an optimal design of...
Design and Manufacturing of a Multi Functional Device For Experimental Fatigue Test and Special Facilities for Symmetric and Anti Symmetric Loading on Gears
, M.Sc. Thesis Sharif University of Technology ; Durali, Mohammad (Supervisor)
Abstract
The goal of this research is design and manufacturing of a device for fatigue test and 3D crack propagation in spur gear roots. Clearly it should be able to test gear in oscillated bending load and control the amplitude and period of loading. Designed setup in this project using a electro hydraulic actuator can do it up to 50 KN and 10 Hz in amplitude and frequency and a PLC controls it during the test time. System can load gears symmetric or anti symmetric and simulate the effect of shaft misalignments, bearing damage and gear production tolerances on the gear loading. System completely designed, built and tested during this project and using experimental data, its performance was...
Wake interference of two identical oscillating cylinders in tandem: An experimental study
, Article Ocean Engineering ; Volume 166 , 2018 , Pages 311-323 ; 00298018 (ISSN) ; Khorasanchi, M ; Day, S ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
This study aims to assess the impact of the spacing between cylinders on their dynamic behaviour. Observations during this experiment have helped to identify the effect of spacing on excitation mechanism of each cylinder as well as establishing the relationship between cylinders response and the spacing between them. Arrays of cylindrical Structures in close proximity are common in variety of engineering structures, particularly in the offshore industry. If the cylinders are flexible, and are subject to excitation from fluid flow, then the dynamics is influenced by complex interactions between the cylinders, dependent on a variety of parameters. Two cylinders were flexibly mounted in tandem...
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
A banach—stone type theorem for space of vector-valued differentiable maps
, Article Analysis Mathematica ; Volume 49, Issue 3 , 2023 , Pages 841-854 ; 01333852 (ISSN) ; Sharif University of Technology
Akademiai Kiado ZRt
2023
Abstract
This article describes the surjective linear isometries between spaces of p-times differentiable maps from a domain of the Euclidean space into a certain Banach space. © 2023, Akadémiai Kiadó
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...