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pezeshki-najafabadi--ali
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Assessing Liquefaction Potential Based on Cone Penetration Test Results
, M.Sc. Thesis Sharif University of Technology ; Ahmadi, Mohammad Mehdi (Supervisor)
Abstract
This study aimed to model the cone penetration test using FLAC 2D software in order to investigate the silty soils that can be found in tailing dams. Additionally, the model of the direct simple shear test was built in the software to estimate the variation of liquefaction potential in these soils with in-situ conditions. It should be noted that the constitutive law used in this study was the NORSAND model which meets the requirements of modeling in both tests. After validating the models, several important parameters are considered as variables to examine their effects on the results of both experiments. Regarding the validation of the models, the constructed numerical models of the cone...
Unfolding of the Gamma-Ray Spectrum of the Scintillator Detectors Using the Neural Network Method
, M.Sc. Thesis Sharif University of Technology ; Vosoughi, Naser (Supervisor)
Abstract
The analysis of gamma-ray spectra of low resolution detectors is difficult and sometimes impossible, as a result of photo peak’s overlapping. The usual methods of radiation spectra analysis based on fitting of peaks to mathematical curves or detecting of peaks with numerical calculation, are valid for high resolution detectors. However these methods are less successful for lower resolution detectors such as the common scintillators. The wide peaks in the spectrum maybe overlap and make it difficult to analysis. To solve this problem, we test here a method, based on the use of the artificial neural network. At first spectra of elements are converted to the patterns which are suitable for the...
Effects of Foundation Uplift on Seismic Performance of 2D Frames Placed on Flexible Foundation
, M.Sc. Thesis Sharif University of Technology ; Ghannad, Mohammad Ali (Supervisor)
Abstract
In conventional method of modeling and design of structures it is assumed that structures are fixedly supported, however, this assumption is generally far from reality; because, not only the majority of buildings’ bases are not stiff enough to suppose them rigid, but also if their foundations are shallow there exist no piles underneath them, they may separate from their bases – the event which is called foundation uplift. Although according to past studies permission of foundation uplift as well as incorporation of base flexibility may markedly affect any structure’s dynamic response, is spite of about half a century which has elapsed since the beginning of these studies, it seems that still...
Coordination Mechanisms in Supply Chain by Contracts
,
Ph.D. Dissertation
Sharif University of Technology
;
Akbari Jokar, Mohammad Reza
(Supervisor)
Abstract
In decentralized Supply Chains, each member decides based on his own interests. Conflict of interests results in suboptimal decisions and poor performance for entire supply chains, as well seriously harms credibly information sharing across them. In this thesis, coordination of decisions in supply chains in the context of Capacity Procurement problem are studied in different situations in form of three models. In first model, a dyadic supply chain with stochastic demand and exogenous price is investigated by taking various costs into account. PARD and RCRS contracts are designed and proposed in order for coordination of decisions respectively in full and partial information updating...
Simultaneous coordination of capacity building and price decisions in a decentralized supply chain
, Article International Journal of Advanced Manufacturing Technology ; Volume 64, Issue 5-8 , 2013 , Pages 961-976 ; 02683768 (ISSN) ; Baboli, A ; Akbari Jokar, M. R ; Sharif University of Technology
2013
Abstract
In this paper, we investigate the simultaneous coordination of price and capacity building decisions in a dyadic supply chain. This problem is a combination of capacity reservation problem and pricing problem. While the coordination of supply chain with stochastic demand and fixed prices has received much attention in the literature, price-dependent and stochastic demand has been less considered. We study the latter case where a price-setting retailer faces a linear decreasing demand with respect to price. To capture the uncertainty of the demand, we add a stochastic variable to the demand function. In addition, we incorporate production rate and inventory cost on the supplier side. We...
Coordination by contract for capacity and price decisions considering stochastic and price-dependent demand settings
, Article 41st International Conference on Computers and Industrial Engineering 2011, 23 October 2011 through 25 October 2011 ; 2011 , Pages 323-329 ; 9781627486835 (ISBN) ; Baboli, A ; Jokar, M. R. A ; Sharif University of Technology
2011
Abstract
In this paper, we investigate the simultaneous coordination of price and capacity building decision in a dyadic supply chain which is in the context of capacity reservation problem. While the coordination in this context with stochastic demand and fixed price has been received much attention in the literature, but the price-dependent and stochastic demand has been less considered. There is a price-setting buyer which faces a linear decreasing demand with respect to price. To capture the uncertainty nature of the demand we add a stochastic variable to the demand function. In addition, we incorporate production time and inventory cost in supplier side. We study the model in both additive and...
Welfare Cost of Fuel Subsidy to Manufacturing Firms
, Ph.D. Dissertation Sharif University of Technology ; Rahmati, Mohammad Hossein (Supervisor) ; Madanizadeh, Ali (Supervisor)
Abstract
This research aims to explore the effectiveness of past tariff evolutions in shaping firms' response to current input prices. Additionally, it investigates how asymmetric fuel pricing across different industries influences overall industry efficiency and prosperity. Furthermore, the study examines the impact of fuel subsidies on the equilibrium distribution of companies independent of welfare decline. In Chapter 1, utilizing microdata from Iranian industrial workshops between 1386-1396 (2007-2017) A key finding is that new firms exhibit a significant and stronger reaction to energy price variations compared to other firms when it comes to technology choices.Chapter 2 presents a structural...
Secondary particles spectra in the decay of a polarized top quark with anomalous tWb couplings
, Article Journal of Physics G: Nuclear and Particle Physics ; Volume 34, Issue 1 , 2007 ; 09543899 (ISSN) ; Sharif University of Technology
2007
Abstract
An analytic expression for energy and angular dependence of a secondary charged lepton in the decay of a polarized top quark with anomalous tWb couplings in the presence of all anomalous couplings are derived. The angular distribution of the b-quark is derived as well. It is presented that the charged lepton spin correlation coefficient is not very sensitive to the anomalous couplings. However, the b-quark spin correlation coefficient is sensitive to anomalous couplings and could be used as a powerful tool in the search for non-SM coupling. © 2007 IOP Publishing Ltd
Semileptonic decay of a polarized top quark in the noncommutative standard model
, Article Physical Review D - Particles, Fields, Gravitation and Cosmology ; Volume 74, Issue 2 , 2006 ; 15507998 (ISSN) ; Sharif University of Technology
2006
Abstract
In this paper we study the noncommutative effects to the lepton spectrum from the decay of a polarized top quark. It is shown that the lowest contribution comes from the quadratic terms of the noncommutative parameter. The deviations from the standard model are significant for small values of the noncommutative characteristic scale. However, the charged lepton spin correlation coefficient has a remarkable deviation from the standard model from very low values of the noncommutative characteristic scale to 1 TeV. © 2006 The American Physical Society
Community Detection in Bipartite Networks
,
M.Sc. Thesis
Sharif University of Technology
;
Hemmatyar, Ali Mohammad Afshin
(Supervisor)
;
Kavousi, Kaveh
(Co-Supervisor)
Abstract
In recent decades, a wide range of research has been done on the characteristics of networks in various domains. Community structure is one of the most important properties in networks. However, most community detection methods designed for unipartite networks. Bipartite networks are very important in many different fields because these networks explicitly shows conceptual connections between different types of entities, for example in bioinformatics science, business, social and economic systems. Recently, community detection in bipartite networks has risen attention by the technical community, due to the accessibility of huge bipartite network data from different domains and the spread of...
Coordination mechanism for capacity reservation by considering production time, production rate and order quantity
, Article Applied Mathematical Modelling ; Volume 37, Issue 20-21 , 2013 , Pages 8796-8812 ; 0307904X (ISSN) ; Akbari Jokar, M. R ; Baboli, A ; Campagne, J. P ; Sharif University of Technology
2013
Abstract
In this paper we study the coordination of a dyadic supply chain producing a high-tech product by contracts. The product has a short life cycle and the buyer faces stochastic demands during the selling period. We consider the production time, which causes the inventory costs on supplier's side. As the supplier builds production capacity in advance, the production rate is limited to the capacity created during the production time. In addition, we take into account the inventory cost and operational cost for the buyer. We examine the model under both full information and partial information updating situations, and propose a coordinating contract for each case. Our analysis includes the study...
A rewarding-punishing coordination mechanism based on Trust in a divergent supply chain
, Article European Journal of Operational Research ; Volume 230, Issue 3 , 2013 , Pages 527-538 ; 03772217 (ISSN) ; Baboli, A ; Cheikhrouhou, N ; Modarres, M ; Akbari Jokar, M. R ; Sharif University of Technology
2013
Abstract
Coordination of decentralized supply chains using contract design is a problem that has been widely addressed in the literature. We consider a divergent supply chain including a supplier and several retailers producing fashion products with short sale seasons. The retailers cooperate with the supplier as sales agents; i.e.; they work in the framework of revenue sharing contracts. Because of their proximity to the market, retailers can provide more accurate demand forecasts to the supplier that is used to decide on issues such as capacity building and market prices with regard to retailers stiff due dates, different lead times and different price-dependent demand functions. To ensure abundant...
Model predictive control of blood sugar in patients with type-1 diabetes
, Article Optimal Control Applications and Methods ; Volume 37, Issue 4 , 2016 , Pages 559-573 ; 01432087 (ISSN) ; Shahrokhi, M ; Sharif University of Technology
John Wiley and Sons Ltd
2016
Abstract
In this article, two adaptive model predictive controllers (AMPC) are applied to regulate the blood glucose in type 1 diabetic patients. The first controller is constructed based on a linear model, while the second one is designed by using a nonlinear Hammerstein model. The adaptive version of these control schemes is considered to make them more robust against model mismatches and external disturbances. The least squares method with forgetting factor is used to update the model parameters. For simulation study, two well-known mathematical models namely, Puckett and Hovorka which describe the dynamical behavior of patient's body have been selected. The performances and robustness of the...
Anomalous single top quark production at the LHC
, Article Physica Scripta ; Volume 82, Issue 3 , 2010 ; 00318949 (ISSN) ; Pooya, G ; Sharif University of Technology
2010
Abstract
The anomalous top quark interactions with gluon (tug, tcg) allow the production of single top quarks at the Large Hadron Collider (LHC). Using the angular distribution of the charged lepton from the W boson in the top decay, we show that with the data of 10 fb-1 of integrated luminosity and in the collisions with the center of mass energy of 14TeV, the anomalous up and charm quarks coupling parameters κu,c/Λ can be measured down to 0.005 and 0.007 TeV-1, respectively
Experimental and analytical study of telescopic lead yielding damper
, Article Journal of Constructional Steel Research ; Volume 150 , 2018 , Pages 371-383 ; 0143974X (ISSN) ; Pournamazian Najafabadi, E ; Sharif University of Technology
2018
Abstract
In this study, a novel type of passive energy dissipation device called a Telescopic Lead Yielding Damper (TLYD) is proposed and analyzed. This device comprises co-axial steel cylinders and lead rings, such that these rings act as shear locks between the steel cylinders. TLYDs dissipate energy through the plastic shear deformation of lead metal. The telescopic mechanism used in TLYDs allows these small-sized dampers to tolerate large axial displacements with low fatigue. For each telescopic level, a yield plateau is added to the hysteresis behavior of TLYD devices. Each yield plateau resists a different performance level, namely design-based and maximum credible earthquakes. Seven...
Wireless electrochemical preparation of gradient nanoclusters consisting of copper(II), stearic acid and montmorillonite on a copper wire for headspace in-tube microextraction of chlorobenzenes
, Article Microchimica Acta ; Volume 185, Issue 1 , 2018 ; 00263672 (ISSN) ; Bagheri, H ; Sharif University of Technology
Springer-Verlag Wien
2018
Abstract
This work introduces a new gradient fiber coating for microextraction of chlorobenzenes. Nanoclusters of organoclay-Cu(II) on a copper wire were fabricated by wireless electrofunctionalization. The resultant gradient coatings are more robust, and thermally and mechanically stable. Wireless electrofunctionalization was carried out in a bipolar cell under a constant deposition potential and using an ethanolic electrolyte solution containing stearic acid and montmorillonite. Stearic acid acts as an inexpensive and green coating while montmorillonite acts as a modifier to impart thermal stability. The gradient morphology of the nanoclusters was investigated by scanning electron microscopy,...
Modeling of retention behaviors of most frequent components of essential oils in polar and non-polar stationary phases
, Article Journal of Separation Science ; Volume 34, Issue 13 , 2011 , Pages 1538-1546 ; 16159306 (ISSN) ; Ebrahimi Najafabadi, H ; Sharif University of Technology
2011
Abstract
The gas chromatography retention indices of 100 different components of essential oils, on three columns with stationary phases of different polarities, were used to develop robust quantitative structure-retention relationship (QSRR) models. Two linear models with only one variable, i.e. solvation entropy, were developed, which explain 95 and 94% of variances of the test set for dimethyl silicone and dimethyl silicone with 5% phenyl group columns, respectively. These models are extremely simple and easy to interpret, but they show higher errors compared with more robust models such as partial least square (PLS) and ridge regressions. For the third column (polyethylene glycol (PEG)), 24...
The use of ladder particle swarm optimisation for quantitative structure-activity relationship analysis of human immunodeficiency virus-1 integrase inhibitors
, Article Molecular Simulation ; Volume 37, Issue 15 , 2011 , Pages 1221-1233 ; 08927022 (ISSN) ; Ebrahimi-Najafabadi, H ; Sharif University of Technology
2011
Abstract
This contribution focuses on the use of ladder particle swarm optimisation (LPSO) on modelling of oxadiazole- and triazolesubstituted naphthyridines as human immunodeficiency virus-1 integrase inhibitors. Artificial neural network (ANN) and Monte Carlo cross-validation techniques were combined with LPSO to develop a quantitative structure-activity relationship model. The techniques of LPSO, ANN and sample set partitioning based on joint x-y distances were applied as feature selection, mapping and model evaluation, respectively. The variables selected by LPSO were used as inputs of Bayesian regularisation ANN. The statistical parameters of correlation of deterministic, R2, and...
Fast Centralized Model Predictive Control of Signal Splitting in Large Scale Urban Road Networks
, M.Sc. Thesis Sharif University of Technology ; Haeri, Mohammad (Supervisor)
Abstract
With the rapid increase in the number of vehicles and the limitations on the extension of transportation network infrastructure, the need for utilizing proper methods to reduce traffic congestion has become increasingly important. One way to reduce traffic congestion is to control the signal splitting of traffic lights. Model predictive control (MPC) has been utilized so far by using different models of traffic flow dynamics in this field. Due to the high computational effort of MPC at each step time, the real-time implementation for large-scale networks has become a big challenge. Store-And-forward (SAF) is one of the traffic flow models that, due to its simplicity, makes it possible to...
Mathematical performance modelling of adaptive wormhole routing in optoelectronic hypercubes
, Article Journal of Parallel and Distributed Computing ; Volume 67, Issue 9 , Volume 67, Issue 9 , 2007 , Pages 967-980 ; 07437315 (ISSN) ; Sarbazi Azad, H ; Sharif University of Technology
2007
Abstract
In this paper, an analytical performance model for adaptive wormhole routing in the hypercube-based optical transpose interconnection system (OTIS-hypercube) is proposed and validated. Using this model, the performance merits of the OTIS-hypercube are discussed. We also compare the performance of the OTIS-hypercube with that of equivalent hypercube network under different implementation constraints. Compared to pure simulation results, the presented model can serve as a more appropriate and compact method to display the performance characteristics of OTIS-hypercube networks. © 2007 Elsevier Inc. All rights reserved