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    A Scheduling Method for Real-Time Tasks in Fog-Based Networks

    , M.Sc. Thesis Sharif University of Technology Motamed Hashemi, Arya (Author) ; Ejlali, Alireza (Supervisor)
    Abstract
    Due to the long physical distance between the users and the cloud data centers, the idea of considering fog layer was established to bring computations closer to the edge of the network, and provide a solution for latency-sensitive applications. In such applications, the tasks are offloaded, and assigned to the available virtual machines in the cloud or fog layers, which directly contribute to Quality of Service (QoS) requirements. Among various applications, the real-time applications require their tasks to finish before their deadlines. Therefore, an assignment or a scheduling algorithm is needed to assign incoming tasks to virtual machines in cloud or fog layer. Most of the research on... 

    Density Functional Theory Study on Interactions between Hydroxyurea as an Anticancer Drug and Tyrosyl Radical

    , M.Sc. Thesis Sharif University of Technology Bayat, Ahmad (Author) ; Fattahi, Alireza (Supervisor) ; Mahmoodi Hashemi, Mohammed (Supervisor)
    Abstract
    Quantum calculation based on the density functional theory (DFT) level and 6-311++G (d,p) basis set was employed to study the relation between the structure and radical scavenging activity of a series of hydroxybenzohydroxamic acid derivatives, namely: [HU]; hyroxyurea, [TX]; 3,4,5-trihydroxybenzamidoxime, [DX]; 3,4-dihydroxybenzohydroxamic acid, [4-HBA]; 4-hydroxybenzohydroxamic acid, [2,3-DHBA]; 2,3-Dihydroxybenzohydroxamic acid, [3,5-DHBA]; 3,5-Dihydroxybenzohydroxamic acid and [2-HBA]; 2-hydroxybenzohydroxamic acid in the gas phase, water and benzene environments. The hydrogen bond property of the studied structures and their radicals as well as radical cations was investigated using... 

    Study on the Kinetics of Uranium Adsorption in the Stirred Reactors, and Search for the Scalable Kinetic Models for This

    , M.Sc. Thesis Sharif University of Technology Hashemi Oalya, Ali (Author) ; Otukesh, Mohammad (Supervisor) ; Khanchi, Alireza (Supervisor)
    Abstract
    One of the main uranium separations of ore that uranium percent application of enhanced design strategies in the industrial cracking furnaces are of practical interest for oil, gas and petrochemical industries. For such engineering purposes the exact simulation of temperature, species concentration and flow fields in the furnace is essential. In this paper, a study was performed to simulate 3D flue gas flow pattern, temperature and species concentration field in the radiation section of an industrial cracking furnace using the computational fluid dynamics (100-500) ppm technique. The steady-state Reynolds Averaged Navier–Stokes (Resin in pulp)equations were solved, in a finite volume scheme,... 

    Synthesis of Metallophthalocyanine Nanoparticls and Its Application in the Oxidation of Organic Compounds,and Investigation of Hydrogen Bonding Effect on the Basicity of Amines and Orbital Interactions on Acidity Enhacment of Alcohols

    , Ph.D. Dissertation Sharif University of Technology Kheirjou, Somayyeh (Author) ; Mahmoodi Hashemi, Mohammad (Supervisor) ; Fattahi, Alireza (Supervisor)
    Abstract
    This thesis is divided into two parts: In part I, which is theoretical part, we were looking for a computational method which is extensively comparable with experimental results to determine pKa of wide variety of organic compounds. The pKa is an important property in many sciences such as chemistry, biology, and material science, since inclination of a compound to donate or accept a proton is fundamental to understanding many chemical and biochemical processes. Experimentally determined pKa values are not always available from literature sources and often estimated values are employed in their place. It is useful, therefore, to have reliable and accurate means of calculating relative and/or... 

    Theoretical Investigation of Hydrogen Bonding Effects on Acidity Enhancement of Beta Diketones in Gas and Solution Phase

    , M.Sc. Thesis Sharif University of Technology Rahimi, Mona (Author) ; Fattahi, Alireza (Supervisor) ; Mahmoodi Hashemi, Mohammad (Supervisor)
    Abstract
    Hydrogen bonding is an important weak interaction encountered in gas and liquid, as well as solid phase. The hydrogen bond plays a very vital role in many life processes and is one of the most frequently used terms in chemistry and biology. Beta diketones have several applications in organic, inorganic and analytical chemistry. Different substituents can affect the acidity of beta diketones. Investigation have shown that hydroxyl function group can increase the acidity of many organic molecules through interamolecular hydrogen bonding. The goal of this project is to investigate the acidity of hydroxyl containing beta diketones in the gas and solution phase. All the gas phase optimizations... 

    Theoretical Investigation of Hydrogen Bonding Effects on Acidity Enhancement of Cyclic Amides and Barbiturates in Gas and Solution Phase

    , M.Sc. Thesis Sharif University of Technology Daneshfar, Maryam (Author) ; Fattahi, Alireza (Supervisor) ; Mahmoodi Hashemi, Mohammad (Supervisor)
    Abstract
    Hydrogen bonding is an important weak interaction encountered in gas, liquid, as well as solid phase. The hydrogen bond plays a very vital role in many life processes and is one of the most frequently used terms in chemistry and biology. Amides have several applications as drugs, antibacterials and antifungals. Different substituents can affect the acidity of amides. Investigation have shown that hydroxyl function group can increase the acidity of many organic molecules through interamolecular hydrogen bonding. The goal of this project is to investigate the acidity of cyclic amides and barbiturates by adding hydroxyl group in the gas and solution phase. All the gas phase optimizations and... 

    Organizational Structure Analysis for Productivity Assessment through Designing the ERP System – Case study, Healthcare Organization

    , M.Sc. Thesis Sharif University of Technology Hashemi Bahramani, Hossein (Author) ; Mostafavi, Mostafa (Supervisor) ; Tavakkolinia, Alireza (Co-Advisor)
    Abstract
    In an era of tight budgets, productivity measurement is a managerial concern. To analyze productivity precisely, real-time productivity measurement through an appropriate IT infrastructure is needed. Enterprise Resource Planning (ERP) is an IT tool which integrates all organizational units and facilitates real-time productivity measurement. To measure productivity levels continuously through an ERP system, organizational structure must be coherent.The main aim of this research is to propose coherent structures for a healthcare organization, as an introduction to facilitate real-time productivity measurement. To accomplish this purpose, present structure of the selected healthcare... 

    Theoretical Investigation of the Structural and Electronic Properties of Ionic Liquids and Their Adsorption on Graphene and Boron-Nitride Surfaces; Synthesis of α-Aminophosphonates Using Fe3O4 Magnetic Nanoparticles

    , Ph.D. Dissertation Sharif University of Technology Shakourian-Fard Jahromi, Mehdi (Author) ; Fattahi, Alireza (Supervisor) ; Mahmoodi Hashemi, Mohammad (Supervisor)
    Abstract
    This thesis is divided into three parts: In part I, structure and electronic properties of ionic liquids based on N7, N9-dimethylguaninium cation and α-amino acid (Gly, His, Phe, Try, and Tyr) anions and also ionic liquids based on 1-ethyl-3-methylimidazolium [emim]+ cation and alkyl-trifluoroborate ([RBF3]-, R=n-CmH2m+1 (m=1-5)) anions were discussed at the DFT(B3LYP)/6-311++G(d,p) level of theory. Then, the effect of chain length in anion on the nature and strength of interaction between cation and anion was investigated. Our results indicated that interaction energy values decrease with the increase in side chain size in anion. NBO and QTAIM results indicated that the interaction in these... 

    Theoretical Investigation of Hydrogen Bonding Effects on Interaction of Metal Nanoclusters with Histidine, Oxidation of Olefins by MnO4– & Acidity Enhancement of Alcohols

    , Ph.D. Dissertation Sharif University of Technology Jebeli Javan, Marjan (Author) ; Fattahi, Alireza (Supervisor) ; Mahmoodi Hashemi, Mohammad (Supervisor) ; Jamshidi, Zahra (Supervisor)
    Abstract
    This thesis is divided into three parts: In part I, interactions of neutral and anionic forms of histidine with coinage metal nano clusters M3 (M = Au, Ag and Cu) are investigated. Results demonstrate that nonconventional M…H-O hydrogen bonds and M-X bonds (X = N, O) play stabilization roles in interactions of histidine and metal nano clusters. Presence of negative charge in ligand leads to increase of binding energy of complexes. In the next step, the effects of coinage metal nano clusters on the gas-phase acidity of weak organic acid (histidine) have been explored. The acidity of isolated histidine is compared with the acidity of its Au3–, Ag3– and Cu3–complexed species. Moreover, pKa... 

    Theoretical Investigation of Hydrogen Bonding Effects on Interaction of Metal Nanoclusters with Biomolecules & Acidity Enhancement of Alcohols

    , Ph.D. Dissertation Sharif University of Technology Ali Akbar Tehrani, Zahra (Author) ; Fattahi, Alireza (Supervisor) ; Mahmoodi Hashemi, Mohammad (Supervisor) ; Jamshidi, Zahra (Co-Advisor)
    Abstract
    This thesis is divided into three parts: In part I, conformational properties of neutral, anionic, cationic and zwitterionic forms of glutathione tripeptide were investigated by means of DFT-B3LYP method with 6-31+G (d,p) basis set. Results show that glutathione is a very flexible molecule and its conformational energy landscape is strongly influenced by forming intramolecular hydrogen bond and its charge. Conformation of each amino acid in glutathione tripeptide depends on its orientation within the peptide sequence in addition to the conformation of other amino acids within the chain. Investigation of intramolecular hydrogen bonds in these conformers by means of AIM analysis demonstrates... 

    Rcci Curvature for Metric-Measure Space via Optimal Transport

    , M.Sc. Thesis Sharif University of Technology Taheri, Abolfazl (Author) ; Bahraini, Alireza (Supervisor) ; Ranjbar Motlagh, Alireza (Co-Advisor)
    Abstract
    One of the important questions in mathematics is generalized. In case of metric spaces, one of the questions is: Can we extend notions of Riemannian geometry to arbitrary metric spaces smoothly? Ricci curvature is one of the most important concepts in differential geometry. Ricci curvature is defined for the Riemannian manifold and has many applications in mathematics and physics like Einstein’s equation in relativity theory. There is a good notion for a metric space having “sectional curvature bounded below by K” or “sectional curvature bounded above by K”, due to Alexandrov. Can we define the concept of Ricci curvature in metric space? A motivation for this question comes from Gromov’s... 

    , M.Sc. Thesis Sharif University of Technology (Author) ; Khaloo, Alireza (Supervisor)
    Abstract
    Seismic design codes reduce loads by using response modification factor. Because of the reserved strength in structural elements and capacity of structure to dissipate energy, structures can be designed for lower seismic loads. This factor has modified over time. In this thesis, the effect of the reduction in behavior factor on the response of two kinds of reinforced concrete systems were evaluated. Moment resisting frames and dual systems with different heights and regularity in plan, heve been design according to the behavior factor which is recommended in the 3rd edition of the Iranian codes of practice for seismic resistance design of buildings (Standard No. 2800). Drift and... 

    Prediction of Financial Markets Using Combination of Artificial Intelligence and Technical Analysis

    , M.Sc. Thesis Sharif University of Technology (Author) ; Haji, Alireza (Supervisor)
    Abstract
    Generally, nowadays, machine learning methods are used in many different areas for their superiority over other methods of prediction. Although being a tough task, stock market prediction with machine learning approaches is being spread due to satisfying results published ever yday. Machine learning methods usually use varied kinds of data ,including structured data such as market data, technical indicators and some fundamental data as well as unstructured one entailing text and graph data in order to enhance their predictability capacity. In this thesis we aimed to find out more about the importance and the contribution of structured data in prediction and we tried to attain a framework... 

    ALR detector for coherent radar detection of rapid fluctuating signals

    , Article IEICE Transactions on Communications ; Volume E83-B, Issue 11 , 2000 , Pages 2519-2525 ; 09168516 (ISSN) Modarres Hashemi, M ; Sharif University of Technology
    Institute of Electronics, Information and Communication, Engineers, IEICE  2000
    Abstract
    In this paper, we consider the coherent radar detection of rapid fluctuating signals in the Gaussian noise. This problem has been previously solved by employing the GLR technique, but we use the ALR to improve the detection performance. So, after deriving an approximate ALR detector, we compare the new detector with the GLR and ' Square-law detectors and we show its superiority  

    Coronary artery lipid accumulation prevention through vibrating piezo electric nano plates embedded in smart stent

    , Article Medical Engineering and Physics ; Volume 118 , 2023 ; 13504533 (ISSN) Ahmadi Arpanahi, R ; Hosseini Hashemi, K ; Ahmadian, M. T ; Mohammadi, B ; Hosseini Hashemi, S ; Sharif University of Technology
    Elsevier Ltd  2023
    Abstract
    Considering the lipid concentration and side effects regarding the stents used by surgeons, a new heart stent model is proposed. In the new stent, a few piezo plates are designed and attached to the stents by which release of the lipids can take place due to the applied alternative voltages. Due to the vibrations of small-scale piezoelectric plates, the deposition of low-density-lipoproteins (LDL) floating in the blood flow in the coronary arteries is prevented. Small-scale effects are considered using nonlocal elasticity theory, and the interaction between fluid and solid is modeled using the Navier-Stokes equation. The effect of fluid parameters as well as applied voltage and geometry... 

    Empirical comparison of sliding friction and wear behaviors of gray and white cast iron

    , Article ASME 2010 10th Biennial Conference on Engineering Systems Design and Analysis, ESDA2010, 12 July 2010 through 14 July 2010, Istanbul ; Volume 1 , 2010 , Pages 489-493 ; 9780791849156 (ISBN) Hashemi, M ; Ghajar, R ; Sharif University of Technology
    2010
    Abstract
    In this paper, sliding friction and wear behaviors of gray cast iron A35 and white cast iron manufactured by quenching from the same cast iron in water were studied and compared by employing pin-on-disk wear tests. Microstructure of the worn surfaces before and after the wear tests were investigated by optical microscope observations. These images show that flakes separated from the surface in gray cast iron due to delamination process, while in white cast iron, the separation of materials from its surface is in the form of powder. In addition, the gray cast iron had higher graphite volume fraction with Type-A graphite flake morphology. The results show that white cast iron has less rate of... 

    Investigation of the small-scale effects on the three-dimensional flexural vibration characteristics of a basic model for micro-engines

    , Article Acta Mechanica ; Volume 226, Issue 9 , September , 2015 , Pages 3085-3096 ; 00015970 (ISSN) Hashemi, M ; Asghari, M ; Sharif University of Technology
    Springer-Verlag Wien  2015
    Abstract
    The coupled three-dimensional flexural vibrations of a micro-rotating shaft–disk system, as a basic model for micro-engines, are investigated in this paper by considering small-scale effects utilizing the modified couple stress theory. Governing equations of motion are derived by the use of Hamilton’s principle. Then, implementing the Galerkin approach, an infinite set of ordinary differential equations is obtained for the system. With truncated two-term equations, expressions for the first two natural frequencies are written, and for the two corresponding modes, the maximum rotational speed up to which the system will be stable is analytically determined. Parametric studies on the results... 

    Analytical study of three-dimensional flexural vibration of micro-rotating shafts with eccentricity utilizing the strain gradient theory

    , Article Meccanica ; Volume 51, Issue 6 , 2016 , Pages 1435-1444 ; 00256455 (ISSN) Hashemi, M ; Asghari, M ; Sharif University of Technology
    Springer Netherlands  2016
    Abstract
    In this work, some vibrational response parameters of strain gradient based micro-spinning Rayleigh beams with mass eccentricity distribution are investigated within infinitesimal deformation conditions. Governing equations of motion are derived utilizing the Hamilton’s principle. The gyroscopic effects and rotary inertia are both included in the formulation. By applying the Galerkin method, analytical expressions for natural frequencies of the micro beam in forward and backward whirl motions are obtained. In addition, an expression for the vibrational amplitude of the micro-beam due to mass eccentricity distribution is determined. Some numerical results are presented to study the effect of... 

    Size-dependent vibrational behavior of a Jeffcott model for micro-rotor systems

    , Article Journal of Mechanical Science and Technology ; Volume 30, Issue 1 , 2016 , Pages 35-41 ; 1738494X (ISSN) Hashemi, M ; Asghari, M ; Sharif University of Technology
    Korean Society of Mechanical Engineers  2016
    Abstract
    In this study, several analytical expressions are obtained for the vibrational characteristics of a Jeffcott model for micro-rotor systems based on the strain gradient theory to investigate the small-scale effects on the model. The Jeffcott model consists of a massless microrotating shaft and a disk as a rotor with eccentricity. The disk is mounted on the middle of the shaft. Two second-order differential equations associated with the oscillating motion of the rotor in the plane perpendicular to the longitudinal axis are presented and transformed into a complex form. The stiffness of the system is determined by obtaining the deflection of a strain-gradient-based nonrotating microbeam... 

    On the size-dependent flexural vibration characteristics of unbalanced couple stress-based micro-spinning beams

    , Article Mechanics Based Design of Structures and Machines ; Volume 45, Issue 1 , 2017 , Pages 1-11 ; 15397734 (ISSN) Hashemi, M ; Asghari, M ; Sharif University of Technology
    2017
    Abstract
    On the basis of the modified couple stress theory, some analytical results are obtained for vibrational parameters of micro-spinning Rayleigh beams with an axial mass-eccentricity distribution. The modified couple stress theory is a nonclassical continuum theory capable to capture the size effects in small-scale structures. After writing the governing equations of motion, they are transformed to the complex form. Then by utilizing the Galerkin method, analytical expressions for natural frequencies of the micro-spinning beam in forward and backward whirl motions are obtained. Critical speeds are also analytically presented in the two whirl motions for different modes. Moreover, the...