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fatemeh-tabatabaei
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ChemInform abstract: microwave-assisted rapid ketalization/acetalization of aromatic aldehydes and ketones in aqueous media [electronic resource]
, Article Journal of Chemical Research ; September 1999, Volume -, Number 9; Page(s) 562 to 563 ; Mirjalili, Bibi Fatemeh ; Sharif University of Technology
Abstract
Aromatic aldehydes and ketones are readily acetalized or ketalized under microwave irradiation in the presence of water as a solvent
Synthesis and characterization of poly(methacrylates) containing spiroacetal and norbornene moieties in side chain [electronic resource]
, Article Journal of Applied Polymer Science ; Volume 77, Issue 1, pages 30–38, 5 July 2000 ; Mirjalili, Bibi Fatemeh ; Sharif University of Technology
Abstract
A four-step synthetic strategy was applied to achieve novel methacrylic monomers. 5-Norbornene-2,2-dimethanol was prepared from a Diels–Alder reaction of cyclopentadiene and acrolein, followed by the treatment of the adduct with an HCHO/KOH/MeOH solution. The resulting 1,3-diol (1) was then acetalized with different aromatic aldehydes having OH groups on the ring to produce four spiroacetal derivatives. The reaction of methacryloyl chloride with the phenolic derivatives led to four new methacrylic monomers that were identified spectrochemically (mass, FTIR, 1H-NMR, and 13C-NMR spectroscopy). Free radical solution polymerization was used to prepare novel spiroacetal–norbornene containing...
Prediction of DNA/RNA Sequence Binding Site to Protein with the Ability to Implement on GPU
, M.Sc. Thesis Sharif University of Technology ; Koohi, Sommaye (Supervisor)
Abstract
Based on the importance of DNA/RNA binding proteins in different cellular processes, finding binding sites of them play crucial role in many applications, like designing drug/vaccine, designing protein, and cancer control. Many studies target this issue and try to improve the prediction accuracy with three strategies: complex neural-network structures, various types of inputs, and ML methods to extract input features. But due to the growing volume of sequences, these methods face serious processing challenges. So, this paper presents KDeep, based on CNN-LSTM and the primary form of DNA/RNA sequences as input. As the key feature improving the prediction accuracy, we propose a new encoding...
Robots’ cooperation for finding a target in streets
, Article 1st IFIP WG 1.8 International Conference on Topics in Theoretical Computer Science, 26 August 2015 through 28 August 2015 ; Volume 9541 , 2016 , Pages 30-43 ; 03029743 (ISSN) ; 9783319286778 (ISBN) ; Ghodsi, M ; Tabatabaei, A
Springer Verlag
2016
Abstract
We study the problem of finding a target t from a start point s in street environments with the cooperation of two robots which have a minimal sensing capability; that is, robots do not know any information about the workspace including information on distances, edges, coordinates, angles etc. They just can detect the discontinuities in the visibility region of their location. The robots can detect target point t as soon as it enters their visibility region and have communication peripherals to send messages to each other. Our aim is to minimize the length of the path passed by the robots. We propose an online algorithm for robots such that they move in the workspace and find the target....
Cross-Lingual Speaker Adaptation for Statistical Parametric Speech Synthesis
, M.Sc. Thesis Sharif University of Technology ; Sameti, Hossein (Supervisor)
Abstract
Speech synthesis and its applications have been very attractive recently. The main purpose of this technique is to produce a speech signal with natural characteristics of human speech like prosody and emotion. Among all existing methods for speech synthesis, statistical parametric speech synthesis methods are more promising because ofhigher flexibility in comparison to other methods. One of the applications of speech synthesis is speech to speech translation. In these systems, the generated voice in target language should have the same characteristics as the input voice in source language. The main purpose of this research is to review and evaluate the cross lingual speaker adaptation...
Hydroelastic Analysis of Surface Piercing Propeller
, M.Sc. Thesis Sharif University of Technology ; Seif, Mohamad Saeed (Supervisor)
Abstract
Surface piercing propellers are particular type of supercavitating propellers that are commonly used for High-speed vessels. Most studies on this type of propellers has been investigating the hydrodynamic forces. But in recent years with increase in SPPs diameter used in vessels, structural analysis of this type of propellers is considered. For this purpose, studies on the stresses exerted on the propeller structures under load is done with the help of Hydro elastic methods. In this type of analysis, structura of propeller is intended to be flexible and Displacements under pressure checked and Tensions resulting from it are studied.
The present Thesis using ANSYS software to analyze a...
The present Thesis using ANSYS software to analyze a...
Design of Low-Power Zero Temperature Coefficient (ZTC) CMOS Oscillators
, M.Sc. Thesis Sharif University of Technology ; Akbar, Fatemeh (Supervisor)
Abstract
The increasing demand for autonomous vehicles and reliable communication protocols and hardware interfaces, such as CAN bus and USB, underscores the necessity for stable clock sources that maintain a low temperature coefficient (TC) over wide temperature ranges. This demand is particularly emphasized in applications such as wearables, network sensors, downhole devices, WSNs, and IoT, where long-lasting battery life and frequency-stable clock sources over a broad temperature range (e.g. -20 °C to 100 °C) are crucial. Traditionally, variations in frequency caused by temperature have been mitigated by employing off-chip components like crystals or ceramic based oscillators, but this approach...
Data-Driven Pricing Based on Demand Prediction Using Machine Learning Methods
, M.Sc. Thesis Sharif University of Technology ; Sedghi, Nafiseh (Supervisor)
Abstract
Pricing plays an important and essential role in the profit and income of companies. The importance of pricing is not only related to its role in the company's profitability, but it also changes the customer's understanding and loyalty towards the company and can create the company's reputation or destroy it. Determining the right price will increase product sales and increase customer loyalty and create a competitive advantage for the company. One of the most important and influential variables in product pricing is the amount of demand. The main challenge of companies for product pricing is the uncertainty in their demand. In order to deal with this problem, data-driven pricing is used....
Silica chloride/wet SiO2 as a novel heterogeneous system for the deprotection of acetals under mild conditions [electronic resource]
, Article Phosphorus, Sulfur, and Silicon and the Related Elements ; Volume 178:2667-2670, Issue 12, 2003 ; Pourjavadi, Ali ; Zolfigol, Mohammad Ali ; Bamoniri, Abdolhamid
Abstract
A combination of silica chloride and wet SiO2 was used as an effective deacetalizating agent for the conversion of acetals to their corresponding carbonyl derivatives under mild and heterogeneous condition
Characterization of Warm Mix Asphalt Containing Reclaimed Asphalt Binders
, M.Sc. Thesis Sharif University of Technology ; Tabatabaei, Nader (Supervisor)
Abstract
Utilization of RAP in HMA reduces the initial costs, conserves natural sources and avoids disposal problems. Aged binder from RAP will have some effects on resultant binder. To date, solvent extraction and recovery is the only method that physically separates the RAP binder from the RAP aggregate for characterization. Time consuming for recovery, altering the physical properties of the recovered asphalt binder like binder hardening and the possibility that Asphalt binder is not completely extracted from the aggregate are the weak points of this method. Addressing the need for non-solvent based RAP binder characterization; procedures for low temperature characterization of RAP binder...
Walking in streets with minimal sensing
, Article Journal of Combinatorial Optimization ; Volume 30, Issue 2 , 2014 , Pages 387-401 ; ISSN: 13826905 ; Ghodsi, M ; Sharif University of Technology
2014
Abstract
We consider the problem of walking a robot in an unknown polygon called “street”, starting from a point (Formula presented.) to reach a target (Formula presented.). The robot is assumed to have minimal sensing capability in a way that cannot infer any geometric properties of the environment, such as its coordinates, angles or distances; but it is equipped with a sensor that can only detect the discontinuities in the depth information (or gaps). Our robot can also locate the target point (Formula presented.) as soon as it enters in robot’s visibility region. In addition, one pebble is assumed to be available to the robot to be used as an identifiable point and to mark any position of the...
Characterization of RAP Binder and Warm Mix Asphalt Containing High RAP Percentage and Crumb Rubber
, M.Sc. Thesis Sharif University of Technology ; Tabatabaei, Nader (Supervisor)
Abstract
Increased environmental concerns and high oil prices have encouraged highway agencies to maximize the use of recycled materials like Reclaimed Asphalt Pavements (RAP) in pavement construction. However, utilization of RAP has limited to low percentage, generally less than 25%. This is due aged, stiffer, and less strain tolerant asphalt binder in RAP. As the RAP proportion increases, a large amount of the aged binder will be introduced into the mixture. The excessive stiffness of HMA mixture tends to lead to less workable mixture. Studies were conducted to examine the effect of Sasobit on the workablility of high RAP mixtures. The results indicated while the utilization of Sasobit had improved...
Study of the Effects of Rrest Time and Loading Time on Viscoplastic Strain of Asphalt Concrtee
, M.Sc. Thesis Sharif University of Technology ; Tabatabaei, Nader (Supervisor)
Abstract
Asphalt concrete exhibits viscoelastic and viscoplastic behavior which is dependent on rate and temperature. To model this behavior, various mechanical modelshave been presented in which total strain, as the response of the applied stress, is decomposed by various researchers to recoverable and permanent strains.Accumulation and expansion of permanent response result in rutting which is a dominant and prevalent distress in hot mixed asphalt (HMA) in hot climates. The available models are not capable of accurately calculate the viscoplastic strain under cyclic loading.
To close this gap, recovered viscoelastic strain at rest (unloading) period was introduced. This parameter accounted for...
To close this gap, recovered viscoelastic strain at rest (unloading) period was introduced. This parameter accounted for...
Discrete Element Simulation of Creep Behavior in Asphalt Mixtures
,
M.Sc. Thesis
Sharif University of Technology
;
Tabatabaei, Nader
(Supervisor)
Abstract
Composite nature of asphalt mixtures necessitates a micromechanical scheme which depends on distinctive characteristics of various constitutive phases. In this regard, discrete element method was utilized to predict the creep behavior of asphalt mixtures and strain response in primary, secondary and tertiary stages. In this research, a modified mixture modeling procedure was considered to better simulate permanent deformation response of asphalt mixtures under creep loading. A random distribution of mastic and aggregate particles with respect to a typical dense gradation was implemented to reconstruct cylindrical specimens. A bonding model represented the cohesion effect in mastic...
Optimal strategy for walking in streets with minimum number of turns for a simple robot
, Article Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) ; Vol. 8881, issue , 2014 , p. 101-112 ; Ghodsi, M ; Sharif University of Technology
2014
Abstract
We consider the problem of walking a simple robot in an unknown street. The robot that cannot infer any geometric properties of the street traverses the environment to reach a target t, starting from a point s. The robot has a minimal sensing capability that can only report the discontinuities in the depth information (gaps), and location of the target point once it enters in its visibility region. Also, the robot can only move towards the gaps while moving along straight lines is cheap, but rotation is expensive for the robot. We maintain the location of some gaps in a tree data structure of constant size. The tree is dynamically updated during the movement. Using the data structure, we...
Walking in streets with minimal sensing
, Article Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), Chengdu ; Volume 8287 LNCS , 2013 , Pages 361-372 ; 03029743 (ISSN); 9783319037790 (ISBN) ; Ghodsi, M ; Sharif University of Technology
2013
Abstract
We consider the problem of walking in an unknown street, starting from a point s, to reach a target t by a robot which has a minimal sensing capability. The goal is to decrease the traversed path as short as possible. The robot cannot infer any geometric properties of the environment such as coordinates, angles or distances. The robot is equipped with a sensor that can only detect the discontinuities in the depth information (gaps) and can locate the target point as soon as it enters in its visibility region. In addition, a pebble as an identifiable point is available to the robot to mark some position of the street. We offer a data structure similar to Gap Navigation Tree to maintain the...
CRA based Control of non-minimum phase fractional order systems
, Article Proceedings of the IEEE International Conference on Control Applications ; 2012 , Pages 855-858 ; 9781467345033 (ISBN) ; Haeri, M ; Sharif University of Technology
2012
Abstract
In this paper the characteristic ratio assignment (CRA) method is employed to control transient response of a class of non-minimum phase fractional order systems. Since fractional order all-pass filter could not be realized, the fractional unstable zeros are converted to integer unstable zeros by multiplying complementary polynomials to numerator and denominator polynomials of system's transfer function. Doing so, the closed loop system would be an integer order all-pass filter multiple an all-pole fractional transfer function determined from CRA method. Computer simulation results are presented to illustrate the performance of the proposed method. m
Sensitivity analysis of CRA based controllers in fractional order systems
, Article Signal Processing ; Volume 92, Issue 9 , September , 2012 , Pages 2040-2055 ; 01651684 (ISSN) ; Haeri, M ; Sharif University of Technology
Elsevier
2012
Abstract
This paper focuses on robust performance analysis of a closed loop fractional order system through a sensitivity approach. The characteristic ratio assignment method is selected to attain a desired closed loop transient response. Then, we compute the sensitivity of such a desired transfer function with respect to its characteristic ratio and we explore its specifications. The relation between the coefficient diagram shape and the relative stability of the closed loop system is discussed. Also, the closed loop poles variations due to the changes in the characteristic ratios are investigated. Finally, we study a pseudo second order process to verify the robust performance of the characteristic...
CRA based control of fractional order systems subject to control signal constraint
, Article International Conference on Control, Automation and Systems ; 2011 , Pages 268-272 ; 15987833 (ISSN) ; 9781457708350 (ISBN) ; Haeri, M ; Sharif University of Technology
2011
Abstract
An approach is proposed to control transient response of fractional order systems with maximum permissible control signal. This goal is achieved using a newly suggested characteristic ratio assignment method. Based on the proposed method, the generalized time constant τ and the characteristic ratios including their pattern, an adjustable parameter β, and the product of two successive characteristic ratios ρ are determined such that predefined level of overshoot and time specification of closed loop step response are obtained while the control signal is confined to a pre assigned maximum magnitude. The raised issue is solved by defining an optimization problem in which the design parameters...
Design of fractional order proportional-integral-derivative controller based on moment matching and characteristic ratio assignment method
, Article Proceedings of the Institution of Mechanical Engineers. Part I: Journal of Systems and Control Engineering ; Volume 225, Issue 8 , December , 2011 , Pages 1040-1053 ; 09596518 (ISSN) ; Haeri, M ; Sharif University of Technology
2011
Abstract
This paper presents a new analytical method to design fractional-order proportional- integral-derivative (PID) controllers. The control parameters are calculated so that the closedloop system approximates a desired transfer function with transient response requirements. This function is determined based on the characteristic ratio assignment method. The control parameters are calculated by matching the first three moments of the closed-loop transfer function with the corresponding values of the desired system. Furthermore, to ensure closed-loop stability the proposed method is improved by using the shifted moments around the crossover frequency. Illustrative examples are given to show the...