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tirandaz--mohammad-rasoul
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Experimental Study of the Pressure Distribution on the Surface of an Infinite Wing Influenced by Different Sweep Angles
, M.Sc. Thesis Sharif University of Technology ; Soltani, Mohammad Reza (Supervisor)
Abstract
A series of wind tunnel tests were performed to examine the effects of wing sweep and wing tip vortices on the pressure distribution of the upper surface of three wings with sweep angles of 23,33 and 40 degrees. The wing section had a laminar flow airfoil similar to that of NACA 6-series airfoils. All tests, were conducted at a chord Reynolds number of 8×〖10〗^5, and for a range of angle of attack -2 to14 degree. Generation of Wing tip vortices are eliminated by placing an End-plate on the wing tip. Static pressure distributions over the upper surface of the wing at three chordwise direction and at one spanwise direction along the quarter chord line are obtained. The results show that the...
A Survey on the Concept of Quantum Theory: Measurement Problem and A Critical Approach to Decoherence Interpretation
, M.Sc. Thesis Sharif University of Technology ; Shafiee, Afshin (Supervisor)
Abstract
Studying the puzzling aspects of quantum phenomenon is quite important subject from different points of view. It must be specially regarded through some major aspects such as: wave-particle dualty, Bell’s theorem no-go theorems, complementarity, entanglement and measurement problem. In this project, we survey subsequently the above topics with a careful attention regarding the measurement problem. One of the most relevant ways claiming to solve measurement problem is the decoherence theory. Scrutinizing the details of formalism and description basis of decoherence, we critically explain and asses the different aspects of this theory
Critical Investigation of Decoherecne Theory in Different Physical Contexts
, Ph.D. Dissertation Sharif University of Technology ; Shafiee, Afshin (Supervisor)
Abstract
Considering the consistency between the predictions of a theory with what is observed in experience, Quantum Mechanics is the most accurate theory in the history of physics. However, is does not present us an unmbigiuos and realistic description about the nature of the microscopic phenomena. At the heart of these issues is the so-called measurement problem. The formalism of the quantum mechanics is unitary and deterministic. Nevertheles, when one does measurements, the unitary process of the evolution of wave-function breaks due to a stochastic abruption. The results of the measurements are in correspondence with the everyday experience of the observer. Yet, the theory itself does not...
Investigation of Make to Order, Make to Stock and Vendor Managed Inventory Replenishment Strategies in Supply Chain Performance
, M.Sc. Thesis Sharif University of Technology ; Hajji, Rasoul (Supervisor)
Abstract
In recent years, numerous companies in various industries apply supply-chain management to improve their market competitiveness. Advances in information technology bring new approaches for managing supply chain activities. Consequently, emphasis on supply-chain coordination has increased in recent years. Vendor managed inventory (VMI) is an important coordination initiative. In VMI, the vendor assumes responsibility for managing inventories at retailers using advanced online messaging and data-retrieval systems. In this dissertation we investigate the effect of VMI on supply chain performance under make-to-order and make-to-stock environment. By using renewal reward theorem, we derive the...
Investigation of Graph Languages in Monadic Second Order Logic and ∆-regular Graph Automaton
, M.Sc. Thesis Sharif University of Technology ; Ardeshir, Mohammad (Supervisor) ; Ramezanian, Rasoul (Co-Advisor)
Abstract
In this thesis, we study monadic second order logic and the languages of graphs. We introduce the notion of ∆- regular graph automaton. Then we designed this finite automaton for processing on labeled graphs. Definability of graph languages which are recognizable by this automaton is shown. To do this, we first briefly introduced monadic second order logic, and then we studied definability of regular string and tree languages in monadic second order logic. In the last section of thesis, ∆- regular graph automaton is introduced
Emergence of molecular chirality due to chiral interactions in a biological environment
, Article Journal of Biological Physics ; Vol. 40, issue. 4 , Jul , 2014 , p. 369-386 ; Ghahramani, F. T ; Shafiee, A ; Sharif University of Technology
2014
Abstract
We explore the interplay between tunneling process and chiral interactions in the discrimination of chiral states for an ensemble of molecules in a biological environment. Each molecule is described by an asymmetric double-well potential and the environment is modeled as a bath of harmonic oscillators. We carefully analyze different time-scales appearing in the resulting master equation at both weak- and strong-coupling limits. The corresponding results are accompanied by a set of coupled differential equations characterizing optical activity of the molecules. We show that, at the weak-coupling limit, chiral interactions prohibit the coherent racemization induced by decoherence effects and...
Dissipative vibrational model for chiral recognition in olfaction
, Article Physical Review E - Statistical, Nonlinear, and Soft Matter Physics ; Volume 92, Issue 3 , 2015 ; 15393755 (ISSN) ; Taher Ghahramani, F ; Shafiee, A ; Sharif University of Technology
American Physical Society
2015
Abstract
We examine the olfactory discrimination of left- and right-handed enantiomers of chiral odorants based on the odorant-mediated electron transport from a donor to an acceptor of the olfactory receptors embodied in a biological environment. The chiral odorant is effectively described by an asymmetric double-well potential whose minima are associated to the left- and right-handed enantiomers. The introduced asymmetry is considered an overall measure of chiral interactions. The biological environment is conveniently modeled as a bath of harmonic oscillators. The resulting spin-boson model is adapted by a polaron transformation to derive the corresponding Born-Markov master equation with which we...
Bringing Schrödinger's cat to life with non-equilibrium respiration
, Article Journal of Optics (United Kingdom) ; Volume 22, Issue 5 , 2020 ; Naeij, H. R ; Shafiee, A ; Sharif University of Technology
IOP Publishing Ltd
2020
Abstract
In this study, we have proposed a method based on non-equilibrium effects to generate the superposition of macroscopically distinguishable quantum states, known as Schrödinger cat states, by using a Mach-Zehnder interferometry type experiment. The interaction of the input number state with a Kerr medium in the presence of a couple of heat baths in different temperatures in the interaction picture and without imposing a Markov assumption is considered. We have shown that the study of dynamics of the cat states under non-equilibrium condition opens up a way for the robustness of quantum features against the destructive role of the environment, even at high temperature limits. It is verified...
Effect of an end plate on surface pressure distributions of two swept wings
, Article Chinese Journal of Aeronautics ; Volume 30, Issue 5 , 2017 , Pages 1631-1643 ; 10009361 (ISSN) ; Masdari, M ; Tirandaz, M. R ; Sharif University of Technology
2017
Abstract
A series of wind tunnel tests was conducted to examine how an end plate affects the pressure distributions of two wings with leading edge (LE) sweep angles of 23° and 40°. All the experiments were carried out at a midchord Reynolds number of 8×105, covering an angle of attack (AOA) range from −2° to 14°. Static pressure distribution measurements were acquired over the upper surfaces of the wings along three chordwise rows and one spanwise direction at the wing quarter-chord line. The results of the tests confirm that at a particular AOA, increasing the sweep angle causes a noticeable decrease in the upper-surface suction pressure. Furthermore, as the sweep angle increases, the development of...
Classicalization of quantum state of detector by amplification process
, Article Physics Letters, Section A: General, Atomic and Solid State Physics ; Volume 383, Issue 15 , 2019 , Pages 1677-1682 ; 03759601 (ISSN) ; Taher Ghahramani, F ; Asadian, A ; Golshani, M ; Sharif University of Technology
Elsevier B.V
2019
Abstract
It has been shown that a macroscopic system being in a high-temperature thermal coherent state can be, in principle, driven into a non-classical state by coupling to a microscopic system. Therefore, thermal coherent states do not truly represent the classical limit of quantum description. Here, we study the classical limit of quantum state of a more relevant macroscopic system, namely the pointer of a detector, after the phase-preserving linear amplification process. In particular, we examine to what extent it is possible to find the corresponding amplified state in a superposition state, by coupling the pointer to a qubit system. We demonstrate quantitatively that the amplification process...
Ownership Structure and Firm Value: Evidence from Tehran Stock Exchange
, M.Sc. Thesis Sharif University of Technology ; Talebian, Masoud (Supervisor) ; Ebrahimnejad, Ali (Supervisor)
Abstract
There are different kinds of ownership structures. In every economy special kinds of these structures are common. These structures include Pyramidal ownership, cross-ownership, etc. These structures empower shareholders to make a gap between their cash flow right and ownership right in a special firm so they could control more firms with the same capital. These structures have their pros and cons, like the internal capital market and tunneling. Of important factors affecting these structures are Legal protection of minor shareholders, shareholder concentration, and largest shareholder. In this research, we find that, unlike most countries, there is a negative relationship between a firm's...
Establishment of ISO/TS 16949:2002 Standard and Combining with Sapco 86 and AR/8601 Saipa Sazeh Gostar Requirements in Auto Parts Manufacturing Company
, M.Sc. Thesis Sharif University of Technology ; Hajji, Rasoul (Supervisor)
Abstract
The quality is the last word of customer satisfaction concept. The structure and the main goal of many of large and small companies have been formed with systems aggregate related to process and product quality. Whereas quality is not achieved only under the protection of inspecting and controlling, then the quality management standards have been designed and produced to control all the activities and organization effective processes. Quality management standards in auto industries have been developed with increasing of customer desire and their severity simultaneously. Which the set of some standards such as ISO 9000, QS 9000, VDA, … and the most ISO TS 16949 requirements have been used....
Economic Batch Quantity (EBQ) for a Single-Stage Production System with Rework and Scrapping
, M.Sc. Thesis Sharif University of Technology ; Haji, Rasoul (Supervisor)
Abstract
The classical economic batch quantity (EBQ) model assumes that all produced items have a perfect quality. But in real-life production systems, generation of defective items is inevitable. A portion of these defective items is considered to be scrap , while the other is assumed to be reworkable and reworking them can reduce costs and increase productivity. In this thesis we have studied the economic batch quantity for a single stage production system with rework and scrapping . We want to satisfy the customer demand and minimize total costs of the system like set up costs , production costs , rework costs , holding costs , shortage costs and scrapping costs . In the first chapter of this...
Systematic Planned (Preventive) Maintenance in Hospitals And Medical Centers of Iran
,
M.Sc. Thesis
Sharif University of Technology
;
Haji, Rasoul
(Supervisor)
Abstract
Based on the latest statistical figures, more than 50 billion Rials worth of medical equipment exists in Iran’s medical centers. In spite of this, Breakdown maintenance is used in all hospitals, which means that the equipment is utilized as long as it is not out of order and only in such a situation, i.e. a breakdown, the necessary repair operation is conducted on the equipment. In fact, no maintenance is carried out to prevent a breakdown, while the “prevention from breakdown” concept has long been introduced in the majority of industries in many countries including Iran and its positive impacts are undisputable. This thesis aims at proposing a solution for the implementation of a “planned...
A Semantic-Aware Authorization Model Based on Deontic Logic
, Ph.D. Dissertation Sharif University of Technology ; Jalili, Rasoul (Supervisor)
Abstract
Semantic technology provides an abstraction layer above existing computational environments, especially the Web, to give information a well-defined meaning. Moving toward semantic-aware environments imposes new security requirements. One of the most important requirement is the authorization and security policy inference based on the existing semantic relationships in the abstract (conceptual) layer. Most of the authorization models proposed for these environments so far are incomplete and their inference rules are not guaranteed to be consistent, sound, and complete. To have a sound and complete system for policy specification and inference, in this thesis, a family of modal logics, called...
Formal Verification of Privacy Property Using Applied Pi Calculus and Epistemic Logic
, M.Sc. Thesis Sharif University of Technology ; Ramezanian, Rasoul (Supervisor)
Abstract
Applied pi calculus is a variant of the pi calculus with extensions for modeling cryptographic protocols. In such a calculus, the security guarantees are usually stated as equivalences. While process calculi provide a natural means to describe the protocols themselves, epistemic logics are often better suited for expressing certain security properties such as secrecy and anonymity. These methods studied in this work to investigation the verification of privacy properties in security protocols. And finally, a new approach is introduced to bridge the gap between these two approaches: using the set of traces generated by a process as models. In this method an epistemic logic has constructs for...
Query Correctness Assurance for Outsourced Databases
, M.Sc. Thesis Sharif University of Technology ; Jalili, Rasoul (Supervisor)
Abstract
In the secure data outsourcing scenario, verification of the reply of an unreliable server includes assessing the authenticity, completeness and it’s integrity. In this thesis, an efficient method, with emphasis on freshness, has been introduced to evaluate the correctness of the replies from a server. It takes in hand different application needs, inherent differences in the data, and different update mechanisms. This method evaluates freshness by using timestamps alongside the data being out sourced. Due to the requirement of verifying not only the freshness of the response, but the correctness of the timestamps as well, two general methods for evaluating and verifying the responses were...
Access Control in Semantic Social Network
, M.Sc. Thesis Sharif University of Technology ; Jalili, Rasoul (Supervisor)
Abstract
Growth of tools that ease sharing information and resources in social networks can cause privacy issues for the users. Protecting user’s personal information against unauthorized access is a crucial task, and it is considered as a first step for preserving user’s privacy in such networks. Policies, access control rules, and the way rules are applied to online social networks are issues that are less investigated and most existing frameworks have used simple models. Growth of users joining social networks and significant volume of resources shared in these networks make such environments suitable for using semantic technology. Semantic technology is used for modeling various resources, users,...
“Determination of Economic Order and Production Quantity in Inventory System Regarding the Quality of Items”
, M.Sc. Thesis Sharif University of Technology ; Haji, Rasoul (Supervisor)
Abstract
EOQ and EPQ models have been among the most important and commonly used techniques for about 100 and 60 years respectively .But, they are involved in some assumptions that sometimes prevent them from being implemented in real situation of industry and production. One of these unrealistic assumptions is that all of items received or produced are of perfect quality. In order to overcome this constraint and make the mentioned models closer to the real environmentsome researches have been done. To this end,following the previous attemptsin this project we assumed to have destructive inspections and existence of imperfect and rejected items after rework. In our models, considering 3 circumstances...
Analysis of Non-monotonicity Property in Access Control for Pervasive Computing Environment
, M.Sc. Thesis Sharif University of Technology ; Jalili, Rasoul (Supervisor)
Abstract
Access control, which is the process of mediating every request to resources and data maintained by a system and determining whether the request should be granted or denied, plays an important role in the system security. The existing of non-monotonicity property in a deduction and decision making process means that some of the previous deductions or decisions may be retracted by adding new information and premises. Based on the definition, in a non-monotonic access control system, adding new information or access control rules may invalidate some of the previous conclusions (permissions/prohibitions). The requirements such as decision making based on the imperfect information, supporting...