Loading...
Search for:
dashti-naserabadi--h
0.116 seconds
Total 8877 records
Direct evidence for conformal invariance of avalanche frontiers in sandpile models
, Article Physical Review E - Statistical, Nonlinear, and Soft Matter Physics ; Volume 79, Issue 3 , Volume 79, Issue 3 , 2009 ; 15393755 (ISSN) ; Moghimi-Araghi, S ; Dashti-Naserabadi, H ; Rouhani, S ; Sharif University of Technology
2009
Abstract
Appreciation of stochastic Loewner evolution (SLEκ), as a powerful tool to check for conformal invariant properties of geometrical features of critical systems has been rising. In this paper we use this method to check conformal invariance in sandpile models. Avalanche frontiers in Abelian sandpile model are numerically shown to be conformally invariant and can be described by SLE with diffusivity κ=2. This value is the same as value obtained for loop-erased random walks. The fractal dimension and Schramm's formula for left passage probability also suggest the same result. We also check the same properties for Zhang's sandpile model. © 2009 The American Physical Society
Roughening transition and universality of single step growth models in (2+1)-dimensions
, Article New Journal of Physics ; Volume 19, Issue 6 , 2017 ; 13672630 (ISSN) ; Saberi, A. A ; Rouhani, S ; Sharif University of Technology
2017
Abstract
We study (2+1)-dimensional single step model for crystal growth including both deposition and evaporation processes parametrized by a single control parameter p. Using extensive numerical simulations with a relatively high statistics, we estimate various interface exponents such as roughness, growth and dynamic exponents as well as various geometric and distribution exponents of height clusters and their boundaries (or iso-height lines) as function of p. We find that, in contrary to the general belief, there exists a critical value at which the model undergoes a roughening transition from a rough phase with in the Kardar-Parisi-Zhang universality to a smooth phase with , asymptotically in...
Statistics of toppling wave boundaries in deterministic and stochastic sandpile models
, Article Journal of Physics A: Mathematical and Theoretical ; Volume 45, Issue 4 , 2012 ; 17518113 (ISSN) ; Azimi Tafreshi, N ; Moghimi Araghi, S ; Sharif University of Technology
2012
Abstract
We study numerically the statistics of curves which form the boundaries of toppling wave clusters in the deterministic Bak, Tang and Wiesenfeld sandpile model and stochastic Manna model on a square lattice. We consider the Abelian version of each model. Multiple tests show that the boundary of toppling wave clusters in both deterministic and stochastic models can be described by SLE curves with diffusivity = 2
Classification of Two-dimensional Surface Growth Models using Schramm -Loewner Evolution
, Ph.D. Dissertation Sharif University of Technology ; Rohani, Shahin (Supervisor) ; Saberi, Abbas Ali (Co-Advisor)
Abstract
Rough surfaces and growth process are the important and significant problems of theoretical and condensed matter physics to model phenomena ranging from the extremely small (biological phenomena) to largest one (Earth’s relief). Although the equations that describe these processes are well defined, but the question of how to characterize these surfaces which display large fluctuations, is open. The existence of (often) scale invariant clusters and very large fluctuations in surface growth process are reminiscent of critical fluctuations in equilibrium systems. Therefore, it is natural to try characterizing the surface by means of critical exponents, i.e., by the scaling dimensions of various...
Three-dimensional Ising model, percolation theory and conformal invariance
, Article EPL ; Volume 92, Issue 6 , 2010 ; 02955075 (ISSN) ; Dashti Naserabadi, H ; Sharif University of Technology
2010
Abstract
The fractal structure and scaling properties of a 2d slice of the 3d Ising model is studied using Monte Carlo techniques. The percolation transition of geometric spin (GS) clusters is found to occur at the Curie point, reflecting the critical behavior of the 3d model. The fractal dimension and the winding angle statistics of the perimeter and external perimeter of the geometric spin clusters at the critical point suggest that, if conformally invariant in the scaling limit, they can be described by the theory of Schramm-Löwner evolution (SLE κ) with diffusivity of κ=5 and 16/5, respectively, putting them in the same universality class as the interfaces in 2d tricritical Ising model. It is...
Stochastic nature of series of waiting times
, Article Physical Review E - Statistical, Nonlinear, and Soft Matter Physics ; Volume 87, Issue 6 , 2013 ; 15393755 (ISSN) ; Aghamohammadi, C ; Dashti Naserabadi, H ; Salehi, E ; Behjat, E ; Qorbani, M ; Khazaei Nezhad, M ; Zirak, M ; Hadjihosseini, A ; Peinke, J ; Tabar, M. R. R ; Sharif University of Technology
2013
Abstract
Although fluctuations in the waiting time series have been studied for a long time, some important issues such as its long-range memory and its stochastic features in the presence of nonstationarity have so far remained unstudied. Here we find that the "waiting times" series for a given increment level have long-range correlations with Hurst exponents belonging to the interval 1/2
Classification of (2+1 ) -dimensional growing surfaces using Schramm-Loewner evolution
, Article Physical Review E - Statistical, Nonlinear, and Soft Matter Physics ; Volume 82, Issue 2 , August , 2010 ; 15393755 (ISSN) ; Dashti Naserabadi, H ; Rouhani, S ; Sharif University of Technology
2010
Abstract
Statistical behavior and scaling properties of isoheight lines in three different saturated two-dimensional grown surfaces with controversial universality classes are investigated using ideas from Schramm-Loewner evolution (SLEκ). We present some evidence that the isoheight lines in the ballistic deposition (BD), Eden and restricted solid-on-solid (RSOS) models have conformally invariant properties all in the same universality class as the self-avoiding random walk (SAW), equivalently SLE8/3. This leads to the conclusion that all these discrete growth models fall into the same universality class as the Kardar-Parisi-Zhang (KPZ) equation in two dimensions
The spatial asymmetric two-dimensional continuous Abelian sandpile model
, Article Journal of Physics A: Mathematical and Theoretical ; Volume 41, Issue 43 , 2008 ; 17518113 (ISSN) ; Dashti Naserabadi, H ; Moghimi Araghi, S ; Sharif University of Technology
2008
Abstract
We insert some asymmetries into the continuous Abelian sandpile models, such as directedness and ellipticity. We analyze probability distribution of different heights and also find the corresponding field theories. Also we find the fields associated with some height variables. © 2008 IOP Publishing Ltd
The Abelian sandpile model on the honeycomb lattice
, Article Journal of Statistical Mechanics: Theory and Experiment ; Volume 2010, Issue 2 , 2010 ; 17425468 (ISSN) ; Dashti Naserabadi, H ; Moghimi Araghi, S ; Ruelle, P ; Sharif University of Technology
2010
Abstract
We check the universality properties of the two-dimensional Abelian sandpile model by computing some of its properties on the honeycomb lattice. Exact expressions for unit-height correlation functions in the presence of boundaries and for different boundary conditions are derived. Also, we study the statistics of the boundaries of avalanche waves by using the theory of SLE and suggest that these curves are conformally invariant and described by SLE 2
Whole-genome analysis of de novo somatic point mutations reveals novel mutational biomarkers in pancreatic cancer
, Article Cancers ; Volume 13, Issue 17 , 2021 ; 20726694 (ISSN) ; Mohseni, A ; Dashti, H ; Beheshti, A ; Dehzangi, A ; Rabiee, H. R ; Alinejad Rokny, H ; Sharif University of Technology
MDPI
2021
Abstract
It is now known that at least 10% of samples with pancreatic cancers (PC) contain a causative mutation in the known susceptibility genes, suggesting the importance of identifying cancer-associated genes that carry the causative mutations in high-risk individuals for early detection of PC. In this study, we develop a statistical pipeline using a new concept, called gene-motif, that utilizes both mutated genes and mutational processes to identify 4211 3-nucleotide PC-associated gene-motifs within 203 significantly mutated genes in PC. Using these gene-motifs as distinguishable features for pancreatic cancer subtyping results in identifying five PC subtypes with distinguishable phenotypes and...
Efficiency improvement of solar stills through wettability alteration of the condensation surface: An experimental study
, Article Applied Energy ; Volume 268 , 2020 ; Soltani Goharrizi, A ; Ayatollahi, S ; Feilizadeh, M ; Dashti, H ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
The condensation process is of great importance in many heat transfer devices in which a large amount of energy must be transferred. Furthermore, condensation is a crucial part of energy conversion and affects the energy efficiency of thermal desalination plants and solar stills. During the condensation process in solar stills, an essential part of the energy is transferred through the condensation surface to produce fresh water. Therefore, the condensation surface plays a significant role in the working efficiency of solar stills. The wettability of the condensation surface influences the condensation mechanism, which, in turn, affects the efficiency of solar stills. This study aims to...
The Effect of Electroporation on Ultrasund Signals
, M.Sc. Thesis Sharif University of Technology ; Zahedi, Edmond (Supervisor)
Abstract
In this thesis, a cellular model of electroporation process and its detection by ultrasound signals is proposed. Electroporation is permeabilization of the cell membrane, caused by an external electric field. The resulted pores open cell’s membrane to large or hydrophilic molecules. The process of Electroporation has been used in Gene therapy and treatment of solid tumors. In this project, first we made a phantom of electroporated tissue and a phantom of normal tissue and then we simulated their responses to a linear array ultrasound transducer. By comparision of received signals from phantoms the probable effect of electroporation on ultrasound RF signals revealed. Results show up to 5 %...
Assessment of meat authenticity using portable Fourier transform infrared spectroscopy combined with multivariate classification techniques
, Article Microchemical Journal ; Volume 181 , 2022 ; 0026265X (ISSN) ; Weesepoel, Y ; Müller Maatsch, J ; Parastar, H ; Kobarfard, F ; Daraei, B ; Yazdanpanah, H ; Sharif University of Technology
Elsevier Inc
2022
Abstract
In the present contribution, the feasibility of portable Fourier transform infrared spectroscopy (FTIR) combined with multivariate classification techniques is assessed for classification of minced beef, lamb, chicken and pork samples. In this regard, both attenuated total reflectance-FTIR (ATR-FTIR) and diffuse reflectance-FTIR (DR-FTIR) methods are evaluated. First, principal component analysis (PCA) was used for exploring FT-IR spectra of four meat species to find similarities and dissimilarities among samples. Additionally, one-class classification (OCC) was utilized as a new approach for halal meat species certification. For OCC, two scenarios were defined: (i) 100% correct...
Asphaltene deposition during CO 2 injection and pressure depletion: A visual study
, Article Energy and Fuels ; Volume 26, Issue 2 , December , 2012 , Pages 1412-1419 ; 08870624 (ISSN) ; Ayatollahi, S ; Alamdari, A ; Zolghadr, A ; Dashti, H ; Kord, S ; Sharif University of Technology
2012
Abstract
Carbon dioxide miscible flooding has become a popular method for Enhanced Oil Recovery (EOR) because it not only efficiently enhances oil recovery but also considerably reduces green house gas emissions. However, it can significantly cause asphaltene deposition, which leads to serious production problems such as wettability alteration, plugging of the reservoir formation, blocking the transportation pipelines, etc. It is crucial to investigate the effects of different factors on asphaltene deposition. A novel experimental setup was prepared to employ a high-pressure visual cell for investigation of asphaltene deposition on a model rock under typical reservoir conditions. The evolution of...
Modeling and simulation of olefin polymerization at microstructure level
, Article Iranian Journal of Chemistry and Chemical Engineering ; Volume 27, Issue 2 , 2008 , Pages 13-22 ; 10219986 (ISSN) ; Ramezani Saadatabadi, A ; Sharif University of Technology
2008
Abstract
A new model based on a combination of the polymeric multigrain and multilayer models has been developed to predict the polymerization rate, particle growth, morphology, effective parameters on broadening of the molecular weight distribution, number and weight average of the molecular weight, isotacticity index and bulk density of polymer. Mathematical correlations and the kinetics used in this model are based on the polymeric multigrain and the multilayer models, respectively. In the modeling, multiplicity of active site using different kinetics parameters as well as Reactivation of catalyst during the polymerization have been considered,. Moreover, it considers mass transfer effects on...
Pan-cancer integrative analysis of whole-genome De novo somatic point mutations reveals 17 cancer types
, Article BMC Bioinformatics ; Volume 23, Issue 1 , 2022 ; 14712105 (ISSN) ; Kazemi, A ; Hamidieh, K ; Dashti, H ; Tahaei, M. S ; Rabiee, H. R ; Alinejad Rokny, H ; Dehzangi, I ; Sharif University of Technology
BioMed Central Ltd
2022
Abstract
Background: The advent of high throughput sequencing has enabled researchers to systematically evaluate the genetic variations in cancer, identifying many cancer-associated genes. Although cancers in the same tissue are widely categorized in the same group, they demonstrate many differences concerning their mutational profiles. Hence, there is no definitive treatment for most cancer types. This reveals the importance of developing new pipelines to identify cancer-associated genes accurately and re-classify patients with similar mutational profiles. Classification of cancer patients with similar mutational profiles may help discover subtypes of cancer patients who might benefit from specific...
The feasibility of two handheld spectrometers for meat speciation combined with chemometric methods and its application for halal certification
, Article Foods ; Volume 11, Issue 1 , 2022 ; 23048158 (ISSN) ; Müller Maatsch, J ; Weesepoel, Y ; Parastar, H ; Kobarfard, F ; Daraei, B ; Aliabadi, M. H. S ; Yazdanpanah, H ; Sharif University of Technology
MDPI
2022
Abstract
Handheld visible-near-infrared (Vis-NIR) and near-infrared (NIR) spectroscopy can be cost-effective, rapid, non-destructive and transportable techniques for identifying meat species and may be valuable for enforcement authorities, retail and consumers. In this study, a handheld Vis-NIR (400–1000 nm) and a handheld NIR (900–1700 nm) spectrometer were applied to discriminate halal meat species from pork (halal certification), as well as speciation of intact and ground lamb, beef, chicken and pork (160 meat samples). Several types of class modeling multivariate approaches were applied. The presented one-class classification (OCC) approach, especially with the Vis-NIR sensor (95–100% correct...
Development of a model for Planning and Management of flood in Multi-Reservoir and Multi-Purpose River Basin (Case Study: Karkheh river basin)
, M.Sc. Thesis Sharif University of Technology ; Abrishmachi, Ahmad (Supervisor)
Abstract
The study of flood control operation in large scale multipurpose reservoir systems is deals with various objectives, such as flood damage reduction, hydropower generation and reliability of the system for supplying demands after flood seasons. The introduction of these objectives, introduces a conflict in objective function where tradeoff must be made. The purpose of this study is helping to decision making process in evaluation, planning and operation phases through preparing the Pareto curves that include various optimum alternatives for operation. For this purpose, we develop a multiobjective optimization model, based on use the mixed-integer linear programming. This model considers two...
Fracture characterizing and modeling of a porous fractured carbonate reservoir
, Article Society of Petroleum Engineers - SPE/EAGE Reservoir Characterization and Simulation Conference 2009 - Overcoming Modeling Challenges to Optimize Recovery, 19 October 2009 through 21 October 2009 ; Volume 1 , 2009 , Pages 303-319 ; 9781615677443 (ISBN) ; Bagheri, M. B ; Ulhaq, S ; Sharif University of Technology
2009
Abstract
Anisotropy and heterogeneity in reservoir properties introduce challenges during the development of hydrocarbon reservoirs in naturally fractured reservoirs. In reservoir simulations, grid-block properties are frequently assigned to obtain reasonable history matches. Even then, accuracy with regard to some aspects of the performance such as water or gas cuts, breakthrough times, and sweep efficiencies may be inadequate. In some cases, this could be caused by the presence of substantial flow through natural fractures. In this work the fracture characterization and modeling was performed in a highly fractured carbonate reservoir in SW Iran. It was observed that reservoir simulation based on...
Development of a Framework for Software Architecture Extraction of Existing Projects Based on Their Requirements
, M.Sc. Thesis Sharif University of Technology ; Habibi, Jafar (Supervisor)
Abstract
The architecture of a software system, its elements and the way they interact is a valuable treasure for understanding the system. If architecture description of a system is not available, working on its extraction and reconstruction should be done. For a software with huge size and vast complexity, architecture extraction by hand and without any predefined method is nearly impossible. So, it is essential for software architecture extractor to use a framework and a well-defined process related to it, for extracting the software architecture. It can help him to use automated tools as much as possible in addition to havingauniquelogicalstructureforperformingthearchitectureextractionprocess. In...