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alaei--yasaman
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A theoretical game approach for two- echelon stochastic inventory system
, Article Acta Polytechnica Hungarica ; Volume 12, Issue 4 , 2015 , Pages 221-239 ; 17858860 (ISSN) ; Hajji, A ; Alaei, R ; Behravesh, M ; Sharif University of Technology
Budapest Tech Polytechnical Institution
2015
Abstract
In this paper, we study the differences between the Centralized and Decentralized approaches in a two-echelon stochastic inventory system under the lost sale policy. We formulate the condition in which the retailer applies (r, Q) inventory policy, and his relation with the upper echelon who acts as a manufacturer. This situation has not been considered in the literature before. The Centralized approach results in optimal solution of the system and the Decentralized one is based on Stackelberg game in which the manufacturer is the leader. The demand arrives according to the stationary Poisson process. We drive the long-run average cost functions, then a set of computational steps are...
Performance evaluation of hybrid transfer switches in grounded and ungrounded medium-voltage electrical systems
, Article CIGRE/IEEE PES International Symposium Quality and Security of Electric Power Delivery Systems, CIGRE/PES 2003, 8 October 2003 through 10 October 2003 ; 2003 , Pages 91-96 ; 2858730156 (ISBN); 9782858730155 (ISBN) ; Mokhtari, H ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2003
Abstract
Application of a fast hybrid transfer switch (HTS) as a suitable tool for protection of sensitive electrical loads against power quality problems has attracted much attentions these days. In this paper, methods for desired control of a HTS which consists of a fast fault-detection method and a suitable firing and transfer strategy are proposed. Simulation results of a HTS under various operating conditions for two types of medium-voltage electrical systems, i.e. grounded (star connection) and ungrounded (delta connection) systems, with respect to total transfer time are presented. The results show the capability of the HTS and the proposed control methods in fast transferring of sensitive...
Cosmic Neutrinos at Neutrino Telescopes CP-violation, Source Properties and Beyond the Standard Model Physics
, Ph.D. Dissertation Sharif University of Technology ; Farzan, Yasaman (Supervisor)
Abstract
In this thesis, we studied the oscillation of neutrino flavors and the measurement of mixing parameters through the detection of cosmic neutrinos at neutrino telescopes. Most of the astrophysical explosions predict the emission of neutrino flux and kilometer-scale detectors are under construction for the observation of these neutrinos. Detection of astrophysical neutrinos opens a new window to understand the neutrino properties and also the properties of astrophysical sources.In this thesis first we review the phenomenology of neutrino flavor oscillation and characteristics of neutrino mass matrix. By introducing a new class of invariants (under general transformation of lepton fields bases)...
Dynamics of Two Coupled Neurons of Different Types of Excitability
, Ph.D. Dissertation Sharif University of Technology ; Razvan, Mohammad Reza (Supervisor)
Abstract
Excitability is one of the most important characteristics of a neuron. In 1948, Hodgkin identified three different types of excitability of neurons. Excitability an all of its types can be observed in Hodgkin-Huxley model of neuronal dynamics (H-H model) as a four-dimensional system of differential equations and in at least two dimensional reductions of H-H type models. By applying the theory of dynamical systems (e.g. bifurcation theory), one can give a mathematical definition of excitability.Excitability of the neuron is equivalent to that the neuronal model is near a bifurcation through which the state of the system approaches to a stable limit cycle. In this thesis, a two-dimensional...
A Game Theoretic Inventory Model for a Two-Echelon Supply Chain with Poisson Demand
, M.Sc. Thesis Sharif University of Technology ; Hajji, Alireza (Supervisor)
Abstract
In this research, we study the differences between the centralized and decentralized approaches in a two-stage serial supply chain including a manufacturer and a retailer under the lost sale policy. The centralized approach results in optimal solution of the system and the decentralized one is based on Stackelberg game in which the manufacturer is the leader. The retailer uses the continuous review (r, Q) policy and the demand arrives according to the stationary Poisson process. In order to obtain the solution for two approaches, a set of computational steps are developed. Furthermore, we provide a numerical example and the corresponding sensitivity analysis to compare the two approaches....
Global analysis of a delay SVEIR epidemiological model
, Article Iranian Journal of Science and Technology, Transaction A: Science ; Volume 37, Issue A4 , 2013 , Pages 483-489 ; 10286276 (ISSN) ; Razvan, M. R ; Yasaman, S ; Sharif University of Technology
2013
Abstract
This paper is concerned with global analysis of a delay SVEIR epidemiological model in a population of varying size. By using Lyapunov stability method and LaSalle's invariance principle for delay systems, we prove that when there is no endemic equilibrium, the disease free equilibrium is globally asymptotically stable, otherwise the endemic equilibrium is globally stable
Particles in the early Universe: Interface of Cosmology and Particles Massive Neutrinos and Cosmology
, M.Sc. Thesis Sharif University of Technology ; Golshani, Mehdi (Supervisor) ; Farzan, Yasaman (Supervisor)
Abstract
Neutrino flavor oscillations are clear evidence of massive neutrinos. It has been for more than a decade that neutrino physics became one of active topics in the field of particle physics and various experiments started studying the flavor oscillation of neutrinos. Unfortunately, experiments studying the flavor oscillations are only sensitive to the mass square difference, and they are incapable of providing more information about the absolute mass scale of neutrinos. Additionally, sterile neutrinos having non-standard interactions are under vast investigations and studies. Determination of neutrino masses and their effective number is among the most challenging problems by which...
Fermi surface nesting and possibility of orbital ordering in FeO
, Article Physics Letters, Section A: General, Atomic and Solid State Physics ; Volume 374, Issue 36 , August , 2010 , Pages 3793-3796 ; 03759601 (ISSN) ; Jafari, S. A ; Sharif University of Technology
2010
Abstract
Remarkable inter-band nesting in FeO Fermi surface, hints to examine energy of orbitally ordered states, which turn out to be more stable. We propose this method as a general scheme to check for possibility of orbital ordering in first principle calculations, and demonstrate it for known examples, LiVO2 and LaMnO3
Evaluation of marketing-pricing decisions in a two-echelon supply chain
, Article Engineering Economics ; Volume 24, Issue 2 , 2013 , Pages 135-143 ; 13922785 (ISSN) ; Behravesh, M ; Karegar, N ; Sharif University of Technology
Kauno Technologijos Universitetas
2013
Abstract
This paper discusses the interaction between one manufacturer and a single retailer in a channel in which both are willing to optimize their profit by adjusting pricing and advertising decisions. The manufacturer produces and sells a product at wholesale price to the retailer who in turn distributes it to consumers with retail price. The market demand is simultaneously affected by retail price, brand advertising of the manufacturer, and local advertising of the retailer. A Cobb-Douglas demand function is used to demonstrate the relationship between the parameters. Decision variables are two firms’ prices and their advertising investments. The problem is modelled under integrated policy and...
Skiptree: a new scalable distributed data structure on multidimensional data supporting range-queries
, Article Computer Communications ; Volume 33, Issue 1 , 2010 , Pages 73-82 ; 01403664 (ISSN) ; Ghodsi, M ; Toossi, M ; Sharif University of Technology
2010
Abstract
This paper presents a new balanced, distributed data structure for storing data with multidimensional keys in a peer-to-peer network. It supports range queries as well as single point queries which are routed in O (log n) hops. Our structure, called SkipTree, is fully decentralized with each node being connected to O (log n) other nodes. We propose modifications to the structures, so that the memory usage for maintaining the link structure at each node is reduced from the worst case of O (n) to O (log n log log n) on the average and O (log2 n) in the worst case. It is also shown that the load balancing is guaranteed to be within a constant factor. Our experimental results verify our...
The relative importance of the business model motive for customer participation in the sharing economy
, Article Sustainable Production and Consumption ; Volume 34 , 2022 , Pages 190-201 ; 23525509 (ISSN) ; Aslani, S ; Talebian, M ; Sharif University of Technology
Elsevier B.V
2022
Abstract
The sharing economy, defined by peer-to-peer interactions through a platform, has been gaining ground in recent years. In this study, we discuss the relative importance of customers' perceived motives to participate in the two most common models of the sharing economy: access-based consumption and ownership-transfer. We focus on taxi-hailing and post-delivery as examples of access-based consumption and second-hand trade as an example of the ownership-transfer. While these two contain heterogeneous business model patterns that can motivate customers differently, common motives are significant in both models. We study common motives and motives aligned with the business model patterns, which...
SkipTree: A Scalable range-queryable distributed data structure for multidimensional data
, Article 16th International Symposium on Algorithms and Computation, ISAAC 2005, Hainan, 19 December 2005 through 21 December 2005 ; Volume 3827 LNCS , 2005 , Pages 298-307 ; 03029743 (ISSN); 3540309357 (ISBN); 9783540309352 (ISBN) ; Toossi, M ; Ghodsi, M ; Sharif University of Technology
2005
Abstract
This paper presents the SkipTree, a new balanced, distributed data structure for storing data with multidimensional keys in a peer-to-peer network. The SkipTree supports range queries as well as single point queries which are routed in O(log n) hops. SkipTree is fully decentralized with each node being connected to O(logn) other nodes. The memory usage for maintaining the links at each node is O(log n log log n) on average and O(log2 n) in the worst case. Load balance is also guaranteed to be within a constant factor. © Springer-Verlag Berlin Heidelberg 2005
Investigating the Behaviour of Some Kind of Fibre-reinforced Concrete
, M.Sc. Thesis Sharif University of Technology ; Khonsari, Vahid (Supervisor)
Abstract
While there are many advantages associated with concrete, including high compressive strength, durability and so forth, on the contrary, it has several disadvantages which may make engineers somewhat reluctant to use it. These include low tensile strength, high brittleness, low resistance to impact, large dimensions of structural cross sections, etc. In recent years, there have been many attempts to surmount these disadvantages by various means such as adding pozzolans, using FRPs, fibres, etc. In this project, the effects of using a special type of high strength steel fibre is studied. In order to investigate the effect of this fibre on the compressive behavior of concrete, 30 cylindrical...
Exploring cognitive activation writing strategies among iranian english language teachers
, Article Language Related Research ; Volume 12, Issue 5 , 2021 , Pages 433-462 ; 23223081 (ISSN) ; Hassanzadeh, M ; Masoudi, M ; Sharif University of Technology
Tarbiat Modares University
2021
Abstract
In order to engage students in higher-level thinking, cognitive activation (CA) strategies have been advanced and utilized in mathematics. CA develops when learners are challenged, confronted with conflicts, asked to think and explain clearly on their learning, and realize connections between new and previous content. Extending the theme to English language teaching (ELT), this study investigated Iranian English language teachers‟ knowledge and practice of cognitive activation writing strategies (CAWS). In so doing, a model was proposed based on a questionnaire that was developed and validated in the present study. Through this scale, knowledge and practice of CAWS by 213 English as a...
Exploring cognitive activation writing strategies among iranian english language teachers
, Article Language Related Research ; Volume 12, Issue 5 , 2021 , Pages 433-462 ; 23223081 (ISSN) ; Hassanzadeh, M ; Masoudi, M ; Sharif University of Technology
Tarbiat Modares University
2021
Abstract
In order to engage students in higher-level thinking, cognitive activation (CA) strategies have been advanced and utilized in mathematics. CA develops when learners are challenged, confronted with conflicts, asked to think and explain clearly on their learning, and realize connections between new and previous content. Extending the theme to English language teaching (ELT), this study investigated Iranian English language teachers‟ knowledge and practice of cognitive activation writing strategies (CAWS). In so doing, a model was proposed based on a questionnaire that was developed and validated in the present study. Through this scale, knowledge and practice of CAWS by 213 English as a...
Human Genome Sequence Analysis Using Statistical and Machine Learning Methods
,
M.Sc. Thesis
Sharif University of Technology
;
Manzuri Shalmani, Mohammad Taghi
(Supervisor)
Abstract
During recent decades, dramatic advances in Genetics and Molecular Biology, has provided scientists with enormous amounts of molecular genomic information of different living organisms, from DNA sequences to complex 3d structures of proteins. This information is raw data which their analysis can provide better understanding of genome mechanisms, discriminating healthy and tumor cells, predicting disease type, making drugs based on genome information, and many more applications. Here, one important issue is the inevitable use of computer science and statistics to analyze these data; such that according to the vast amount of data, would provide intelligent methods, which yield most accurate...
Study of Customers’ Motivations and the Impact of Touchpoints on Motives to Use Different Industries of the Sharing Economy
, M.Sc. Thesis Sharif University of Technology ; Talebian, Masoud (Supervisor) ; Aslani, Shirin (Supervisor)
Abstract
With the rise of the sharing economy, customers’ motivations to participate has become a controversial phenomenon. The sharing economy has different industries that might itself be a reason for the emergence of different incentives in customers. Moreover, these industries can affect motivation by controlling various touchpoints Two dimensions, quantity and quality illustrate the impact of touchpoints The encounter of touchpoints with both of the provider and consumer side might confuse companies to choose the best composition of has been conducted to identify the importance of motives to use different industries of the sharing economy and examine the impact of the brands’ touchpoints . In...
A Machine Learning Simulator for Task Offloading and Resource Allocation in IoV
, M.Sc. Thesis Sharif University of Technology ; Bayat Sarmadi, Siavash (Supervisor)
Abstract
Recent years have witnessed significant advancements in the smart transportation industry. Timely execution of processes and tasks prior to deadlines is crucial and sensitive. With the advancement of the automotive industry and smart transportation vehicles, the number of smart vehicles is increasing day by day. However, not all devices can perform their respective tasks on time, hence the need for edge network servers to assist in task execution .Decision-making regarding task execution methods and resource allocation in mobile networks poses a significant challenge. In recent research, given the complexity of the issue and the advancements in machine learning algorithms, the efficacy of...
Study on Structure, Mechanical Properties, and Flammability of PC/ABS
, M.Sc. Thesis Sharif University of Technology ; Bagheri, Reza (Supervisor) ; Seyed Reyhani, Morteza (Supervisor)
Abstract
Polycarbonate (PC) is known as one of the engineering plastics with remarkable mechanical properties, but the application of this polymer is limited due to its high notch sensitivity. Blending polycarbonate with other polymers such as acrylonitrile butadiene styrene (ABS) is a method to resolve this disadvantage. PC/ABS blends are commonly used in automotive industry, electrical and electronic devices. As PC and ABS are not completely miscible, a variety of compatibilizers are used to achieve a suitable microstructure and high engineering properties. Considering crucial applications of PC/ABS blends, different flame retardants are also used to reduce the flammability. These flame retardants...
Dithiocarbamates as an efficient intermediate for the synthesis of 2-(alkylsulfanyl)thiazoles in water
, Article Tetrahedron Letters ; Volume 57, Issue 8 , 2016 , Pages 883-886 ; 00404039 (ISSN) ; Hasani, L ; Ali Alaei, M ; Saidi, M.R ; Sharif University of Technology
Elsevier Ltd
2016
Abstract
A simple, green and high-yielding procedure for the synthesis of 4-substituted-2-(alkylsulfanyl)thiazoles from the reaction of dithiocarbamates and α-halocarbonyl containing compounds in water is described. Also, a one-pot, two-step procedure for the synthesis of 2-(alkylsulfanyl)thiazoles from acetophenone and dithiocarbamates was developed. © 2016 Elsevier Ltd. All rights reserved