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Development of grid resource discovery service based on semantic information
, Article SpringSim '07: Proceedings of the 2007 spring simulaiton multiconference ; Volume 1 , 2007 , Pages 141-148 ; 07359276 (ISSN) ; 1565553128 (ISBN); 9781565553125 (ISBN) ; Moshkenani, M. S ; Sharif University of Technology
2007
Abstract
Grid computing is a type of parallel and distributed system that provides the possibility of sharing, choosing and collecting the autonomous resources (such as computer, software, databases, and equipments) that are distributed geographically. Resource discovery is one of the key subjects in distributed systems and especially Grids. We should consider that Grid consists of different applications that each of them consist of different hardware and software resources, therefore recognizing these resources is important in a Grid system. Classical approaches to Grid resource discovery are either centralized or hierarchical [1] (and will maybe prove inefficient as the scale of Grid systems...
Harmonic class loading for damage identification in beams using wavelet analysis
, Article Structural Health Monitoring ; Volume 6, Issue 1 , 2007 , Pages 67-80 ; 14759217 (ISSN) ; Golafshani, A. A ; Beheshti Aval, S. B ; Noori, M ; Sharif University of Technology
2007
Abstract
The harmonic displacement response of a beam is utilized as the input signal function in wavelet analysis. Sudden changes in the spatial variation of transformed response identify the location of damages and defects. The damage incurred causes a change in the stiffness or mass of the beam. This causes a localized singularity which can be identified by a wavelet analysis of the displacement response. In this article, it is shown that using harmonic response is superior to the static deflection response and this approach is more effective in the presence of noise and more sensitive to the versatility of the applied harmonic loads. © 2007 SAGE Publications
Mammograms enhancement using wavelet transform and piecewise linear and nonlinear coefficient mapping
, Article Middle East Conference on Biomedical Engineering, MECBME ; Feb , 2014 , p. 107-110 ; Noubari, H. A ; Fatemizadeh, E ; Rezaee, M ; Khalili, M ; Sharif University of Technology
2014
Abstract
In this paper a multi-scale image enhancement strategy using wavelets as applied to digital mammograms is presented. For multiresolution wavelet analysis redundant dyadic discrete wavelet transform is utilized to allow translation invariance and low resolution enhancement capability. Two alternative nonlinear gain adjustments, piecewise linear and Gaussian form of gain adjustment are used for coefficient modification for the enhancement of subtle details such as microcalcification and low resolution edges of different lesion types. The results of comparing these methods of gain adjustment are presented. This comparing has done by defining new parameters for measuring quality of image based...
Sub-pixel image registration based on physical forces
, Article 2010 International Conference on Wireless Communications and Signal Processing, WCSP 2010, 21 October 2010 through 23 October 2010, Suzhou ; 2010 ; 9781424475551 (ISBN) ; Ghorbani, S ; Beheshti Shirazi, A. A ; Sharif University of Technology
2010
Abstract
A new method for image registration has been previously proposed by the authors, which the registration is based on physical forces. The registration parameters are translation and rotation. This method assumes images like charged materials that attract each other. In this case, one of the images moves in the same direction as the applied force while the other one is still. The movement of the image continues until the resultant force becomes zero. This approach estimates the registration parameters simultaneously and leading to a better optimized set of registration parameters. The registration error for this method is 1 to 3 pixels. In this paper we aim to develop this method for the...
Efficient electrochemical CO2 conversion by cobalt-based metal organic frameworks modified by bimetallic gold-silver nanostructures
, Article Catalysis Science and Technology ; Volume 13, Issue 12 , 2023 , Pages 3645-3654 ; 20444753 (ISSN) ; Saeidi, M ; Adel Rastkhiz, M ; Shahrestani, S ; Zarrabi, A ; Bai, J ; Simchi, A ; Akbarmolaie, S ; Sharif University of Technology
Royal Society of Chemistry
2023
Abstract
The ongoing and rapid growth of atmospheric CO2 levels causes a crucial worldwide concern. Herein, an efficient electrocatalyst has been introduced for electrochemical CO2 reduction reaction (CO2RR) to address the stability issue of ZIF-67. The catalyst consists of gold and silver nanostructures electrodeposited on the surface of a cobalt-based metal-organic framework (Au-Ag@ZIF-67). The uniform distribution of the Au-Ag alloy without any agglomeration on ZIF-67 was confirmed through microscopic observations. After 13.3 h of CO2RR, the specific surface area of Au-Ag@ZIF-67 slightly decreased, whereas that of ZIF-67 declined drastically, indicating excellent structural stability of the Au-Ag...
Non-fragile control and synchronization of a new fractional order chaotic system
, Article Applied Mathematics and Computation ; Volume 222 , 2013 , Pages 712-721 ; 00963003 (ISSN) ; Delshad, S. S ; Hamidi Beheshti, M. T ; Tavazoei, M. S ; Sharif University of Technology
2013
Abstract
In this paper, we address global non-fragile control and synchronization of a new fractional order chaotic system. First we inspect the chaotic behavior of the fractional order system under study and also find the lowest order (2.49) for the introduced dynamics to remain chaotic. Then, a necessary and sufficient condition which can be easily extended to other fractional-order systems is proposed in terms of Linear Matrix Inequality (LMI) to check whether the candidate state feedback controller with parameter uncertainty can guarantee zero convergence of error or not. In addition, the proposed method provides a global zero attraction of error that guarantees stability around all existing...
Robust synchronization of perturbed Chen's fractional-order chaotic systems
, Article Communications in Nonlinear Science and Numerical Simulation ; Volume 16, Issue 2 , 2011 , Pages 1044-1051 ; 10075704 (ISSN) ; Hamidi Beheshti, M. T ; Tavazoei, M. S ; Sharif University of Technology
2011
Abstract
In this paper, based on a stability theorem proved for linear fractional-order systems, a scheme for robust synchronization of two perturbed fractional-order Chen systems is proposed. In the proposed scheme, both master and slave systems are considered to be involved with external disturbances having unknown values. It is analytically shown that any set of bounded external disturbances can be damped by the proposed method, where synchronization error will be forced and then kept inside a ball around the origin. Since during the design procedure the radius of this ball could be easily chosen by the designer, the synchronization can be done with any desired accuracy. The proposed method can be...
An efficient fractal method for detection and diagnosis of breast masses in mammograms
, Article Journal of Digital Imaging ; Vol. 27, issue. 5 , 2014 , pp. 661-669 ; ISSN: 08971889 ; AhmadiNoubari, H ; Fatemizadeh, E ; Khalili, M ; Sharif University of Technology
2014
Abstract
In this paper, we present an efficient fractal method for detection and diagnosis of mass lesion in mammogram which is one of the abnormalities in mammographic images. We used 110 images that were carefully selected by a radiologist, and their abnormalities were also confirmed by biopsy. These images included circumscribed benign, ill-defined, and spiculated malignant masses. Firstly, we discriminated lesions automatically using new fractal dimensions. The results which were examined by different types of breast density showed that the proposed method was able to yield quite satisfactory detection results. Secondly, noting that contours of masses playing the most important role in diagnosis...
Robust outer synchronization between two complex networks with fractional order dynamics
, Article Chaos ; Volume 21, Issue 3 , 2011 ; 10541500 (ISSN) ; Míguez, J ; Hamidi Beheshti, M. T ; Tavazoei, M. S ; Sharif University of Technology
2011
Abstract
Synchronization between two coupled complex networks with fractional-order dynamics, hereafter referred to as outer synchronization, is investigated in this work. In particular, we consider two systems consisting of interconnected nodes. The state variables of each node evolve with time according to a set of (possibly nonlinear and chaotic) fractional-order differential equations. One of the networks plays the role of a master system and drives the second network by way of an open-plus-closed-loop (OPCL) scheme. Starting from a simple analysis of the synchronization error and a basic lemma on the eigenvalues of matrices resulting from Kronecker products, we establish various sets of...
Classification of abnormalities in mammograms by new asymmetric fractal features
, Article Biocybernetics and Biomedical Engineering ; Volume 36, Issue 1 , 2016 , Pages 56-65 ; 02085216 (ISSN) ; Ahmadi Noubari, H ; Fatemizadeh, E ; Khalili, M ; Sharif University of Technology
PWN-Polish Scientific Publishers
2016
Abstract
In this paper we use fractal method for detection and diagnosis of abnormalities in mammograms. We have used 168 images that were carefully selected by a radiologist and their abnormalities were also confirmed by biopsy. These images included asymmetric lesions, architectural distortion, normal tissue and mass lesion where in case of mass lesion they included circumscribed benign, ill-defined and spiculated malignant masses. At first, by using wavelet transform and piecewise linear coefficient mapping, image enhancement were done. Secondly detection of lesions was done by fractal method as a ROI. Since in investigation of breast cancer, it is important that fibroglandular tissues in both...
On the nonlinear dynamic responses of FG-CNTRC beams exposed to aerothermal loads using third-order piston theory
, Article Acta Mechanica ; Volume 229, Issue 6 , 2018 , Pages 2413-2430 ; 00015970 (ISSN) ; Rabiei Beheshti, A ; Sharif University of Technology
Springer-Verlag Wien
2018
Abstract
The purpose of this study is to analyze the nonlinear dynamic responses of functionally graded carbon nanotube-reinforced composite (FG-CNTRC) beams exposed to axial supersonic airflow in thermal environments. The dynamic model of the FG-CNTRC beam is developed with regard to the first-order shear deformation theory incorporating the von Kármán geometrical nonlinearity. The thermomechanical properties of the constituents are assumed to be temperature dependent. The third-order piston theory is adopted to estimate the nonlinear aerodynamic pressure induced by the supersonic airflow. Harmonic differential quadrature method is implemented to discretize the equations of motion in the spatial...
Entanglement-assisted communication in the absence of shared reference frame
, Article Physical Review A ; Volume 99, Issue 4 , 2019 ; 24699926 (ISSN) ; Raeisi, S ; Karimipour, V ; Sharif University of Technology
American Physical Society
2019
Abstract
Alice wants to convey the value of a parameter to Bob with whom she does not share a reference frame. What physical object can she use for this task? Shall she encode this value into the angle between two physical vectors such as the angle between two spins? Can she benefit from using entanglement? We investigate these questions here and show that an entangled state of two qubits has three parameters that are invariant under changes of the reference frame. We also calculate for specific examples the average information gain for different circumstances, where one of these parameters is used for communication. We compare our result with the special case of separable states and find that...
Prediction of current-induced local scour around complex piers: Review, revisit, and integration
, Article Coastal Engineering ; Volume 133 , 2018 , Pages 43-58 ; 03783839 (ISSN) ; Ataie Ashtiani, B ; Beheshti, A ; Hadjzaman, M ; Jamali, M ; Sharif University of Technology
Elsevier B.V
2018
Abstract
Complex piers (CPs), consisting of a column, pile cap and pile group, are commonly built as foundations for hydraulic and marine structures. Scour-hole development around CPs is studied in this paper. A total of 52 tests is carried out on 4 CP models, with experiments durations ranging from 24 to 120 h. All of the available experimental data for clear-water scour around CPs including the collected data of the present study and those previously published are reviewed and combined into a database. A special case of bridge piers with deep foundation or caisson instead of pile caps is also considered, which is herein called compound piers. The database contains 367 experiments for CPs and 162...
Scour hole influence on turbulent flow field around complex bridge piers
, Article Flow, Turbulence and Combustion ; Volume 97, Issue 2 , 2016 , Pages 451-474 ; 13866184 (ISSN) ; Ataie Ashtiani, B ; Sharif University of Technology
Springer Netherlands
2016
Abstract
Experimental results of detailed flow measurements using an Acoustic-Doppler Velocimeter (ADV) around a complex bridge pier (CBP) are presented. The pier consists of a column, a pile cap (PC) and a 2×4 pile group. The time-averaged velocities, turbulence intensities, and Reynolds stresses are studied and presented at different horizontal and vertical planes. Streamlines obtained from the velocity fields are used to show the complexity of the flow around the pier. It is shown that the main feature of the flow responsible for the entrainment of the bed sediments is a contracted (pressurized) flow below the PC toward the piles. A deflected flow around the PC and a strong down-flow along its...
Discussion of “Neuro-fuzzy GMDH systems based evolutionary algorithms to predict scour pile groups in clear water conditions” by M. Najafzadeh
, Article Ocean Engineering ; Volume 123 , 2016 , Pages 249-252 ; 00298018 (ISSN) ; Ataie Ashtiani, B ; Sharif University of Technology
Elsevier Ltd
2016
Abstract
The author utilized neuro-fuzzy based group method of data handling (NF-GMDH) to predict the local scour depth around pile groups under clear-water conditions. They collected the datasets from literature. To predict the local scour by using NF-GMDH, nine dimensional parameters were considered to define a functional relationship between input and output variables. The results of NF- GMDH networks were compared with that of the empirical equations. However, the collected datasets for pile group scouring, the method of implementing the empirical formula to calculate scour depth, and using the equation of Sheppard et al. (2004) suggested for single pier to predict local scouring around pile...
Experimental study of three-dimensional flow field around a complex bridge pier
, Article Journal of Engineering Mechanics ; Volume 136, Issue 2 , 2010 , Pages 143-154 ; 07339399 (ISSN) ; Ataie Ashtiani, B ; Sharif University of Technology
2010
Abstract
In this paper, three-dimensional turbulent flow field around a complex bridge pier placed on a rough fixed bed is experimentally investigated. The complex pier foundation consists of a column, a pile cap, and a 2×4 pile group. All of the elements are exposed to the approaching flow. An acoustic-Doppler velocimeter was used to measure instantaneously the three components of the velocities at different horizontal and vertical planes. Profiles and contours of time-averaged velocity components, turbulent intensity components, turbulent kinetic energy, and Reynolds stresses, as well as velocity vectors are presented and discussed at different vertical and horizontal planes. The approaching...
Analysis of threshold and incipient conditions for sediment movement
, Article Coastal Engineering ; Volume 55, Issue 5 , 2008 , Pages 423-430 ; 03783839 (ISSN) ; Ataie Ashtiani, B ; Sharif University of Technology
2008
Abstract
Prediction of threshold conditions and incipient motion is the essential issue for the study of sediment transport. This work compares existing empirical threshold curves proposed for Shields diagram, a method based on the concept of probability of sediment movement, and an empirical method based on movability number. These methods are used to predict the incipient motion conditions for experimental runs taken from various studies. Most of the experimental data, used in this work, have not been used before in derivation of alternative formulations for Shields diagram and other methods. The empirical threshold curves based on the Shields entrainment function was the least successful at...
Three dimensional analysis of an AC electric arc furnace
, Article IECON Proceedings (Industrial Electronics Conference), 3 November 2009 through 5 November 2009 ; 2009 , Pages 3697-3702 ; Nazari, A ; Ataei, M ; Khademhosseini Beheshti, H ; Karimi, H ; Sharif University of Technology
2009
Abstract
AC electric arc furnaces (EAFs) highly reduce power quality of the network by generating disturbances such as flicker and harmonics. These disturbances are due to the nonlinear electromagnetic and thermal field behaviors of the AC arcs. Analysis of these nonlinear behaviors is required for improving power quality in the network. This paper presents a three-dimensional finite element modeling of the electromagnetic fields in an AC three-phase electric arc furnace. The model includes the electrodes, arcs and molten bath. Current density, voltage and magnetic field intensity in the arcs, molten bath and electrodes are predicted as a result of applying the three-phase AC voltages to the EAF....
Nonlinear seismic behavior of elliptic-braced moment resisting frame using equivalent braced frame
, Article Steel and Composite Structures ; Volume 40, Issue 1 , 2021 , Pages 45-64 ; 12299367 (ISSN) ; Haghollahi, A ; Talebi Kalaleh, M ; Beheshti Aval, B ; Sharif University of Technology
Techno-Press
2021
Abstract
Recently, the elliptic-braced moment resisting frame (ELBRF) which is a new lateral bracing system installed in the middle bay of the frame in the facade of buildings is introduced. This system not only prevents a solution for opening space problem in view of architectural aspects, but also improves the structural behavior. The main drawback of its using in view of numerical modeling in multistory buildings is lack of curved frame element in design and analysis software. To overcome this shortcoming, in this paper, for the first time, an equivalent element for elliptic brace is presented for ELBRF through a laboratory program and nonlinear finite element analysis, which will contribute to...
Designing and implementing basic sciences ontology based on concepts and relationships of relevant thesauri
, Article Iranian Journal of Information Processing Management ; Volume 30, Issue 3 , Nov , 2015 , Pages 677-696 ; 22518223 (ISSN) ; Ejei, F ; Sharif University of Technology
Iranian Research Institute for Scientific Information and Documentation
2015
Abstract
Currently, the main portion of knowledge is stored in electronic texts and documents and for transferring that knowledge effectively, we must use proper methods to gather and retrieve relevant information. Ontologies provide means to produce structured documents and use intelligent search instead of keyword search. Ontology defines the common words and concepts used to describe and represent an area of knowledge. However, developing ontologies is a time consuming and labor work. So, many ontology developers try to facilitate and speed up this process by reusing other resources. In fact, thesaurus contains semantic information and hierarchical structure that make it an appropriate resource...