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    Effect of Environmental Interactions on Evolutionary Dynamics in Graph Structures

    , M.Sc. Thesis Sharif University of Technology Nemati, Hossein (Author) ; Ejtehadi, Mohammad Reza (Supervisor) ; Kaveh, Kamran (Co-Supervisor)
    Abstract
    Environmental heterogeneity, or environmental interactions in evolutionary graphs can drastically change the population dynamics compared to the uniform environment. Such heterogeneity can be imposed in different ways. In this study we choose periodic pattern for the environmental heterogeneity with different values for amplitude and period. Imposing periodic heterogeneity on cyclic graphs, we studied the fixation probability and time. We use birth-death Moran model as the update rule. We observe that with such heterogeneity, an advantageous type in the uniform environment can turn into deleterious in the presence of heterogeneity. Also, the opposite way can happen. The results show that... 

    Effect of Migration on Moran’s Evolutionary Dynamics

    , M.Sc. Thesis Sharif University of Technology Gorgi, Melika (Author) ; Ejtehadi, Mohammad Reza (Supervisor) ; Kaveh, Kamran (Co-Supervisor)
    Abstract
    Natural selection in structured populations is considered a crucial subject in evolutionary and population genetics. There is no explicit relationship between discrete-time stochastic models such as the Moran process and continuous-time models such as the Fisher-Kolmogorov equation. However, under specific conditions and within the limits of natural selection and weak selection, a connection can be found between these two models. To gain a better understanding of the specific relationship between these two models, we obtain partial differential equations for the spatiotemporal dynamics of natural selection by extending the birthdeath and death-birth processes of the Moran process to a... 

    Dark silicon and the history of computing

    , Article Advances in Computers ; Volume 110 , 2018 , Pages 1-33 ; 00652458 (ISSN); 9780128153581 (ISBN) Lotfi Kamran, P ; Sarbazi Azad, H ; Sharif University of Technology
    Academic Press Inc  2018
    Abstract
    For many years, computer designers benefitted from Moore's law and Dennard scaling to significantly improve the speed of single-core processors. The failure of Dennard scaling pushed the computer industry toward homogenous multicore processors for the performance improvement to continue without significant increase in power consumption. Unfortunately, even homogeneous multicore processors cannot offer the level of energy efficiency required to operate all the cores at the same time in today's and especially tomorrow's technologies. As a result of lack of energy efficiency, not all the cores in a multicore processor can be functional at the same time. This phenomenon is referred to as dark... 

    Temporal prefetching

    , Article Advances in Computers ; 2021 ; 00652458 (ISSN) Lotfi-Kamran, P ; Sarbazi Azad, H ; Sharif University of Technology
    Academic Press Inc  2021
    Abstract
    Many applications, including big-data server applications, frequently encounter data misses. Consequently, they lose significant performance potential. Fortunately, data accesses of many of these applications follow temporal correlations, which means data accesses repeat over time. Temporal correlations occur because applications usually consist of loops, and hence, the sequence of instructions that constitute the body of a loop repeats many times, leading to data access repetition. Temporal data prefetchers take advantage of temporal correlation to predict and prefetch future memory accesses. In this chapter, we introduce the concept of temporal prefetching and present two instances of... 

    Spatial prefetching

    , Article Advances in Computers ; 2021 ; 00652458 (ISSN) Lotfi Kamran, P ; Sarbazi Azad, H ; Sharif University of Technology
    Academic Press Inc  2021
    Abstract
    Many applications extensively use data objects with a regular and fixed layout, which leads to the recurrence of access patterns over memory regions. Spatial data prefetching techniques exploit this phenomenon to prefetch future memory references and hide their long latency. Spatial prefetchers are particularly of interest because they usually only need a small storage budget. In this chapter, we introduce the concept of spatial prefetching and present two instances of spatial data prefetchers, SMS and VLDP. © 2021 Elsevier Inc  

    Preface

    , Article Advances in Computers ; Volume 125 , 2022 , Pages ix-x ; 00652458 (ISSN); 9780323851190 (ISBN) Lotfi Kamran, P ; Sarbazi Azad, H ; Sharif University of Technology
    Academic Press Inc  2022

    Temporal prefetching

    , Article Advances in Computers ; Volume 125 , 2022 , Pages 31-41 ; 00652458 (ISSN); 9780323851190 (ISBN) Lotfi-Kamran, P ; Sarbazi Azad, H ; Sharif University of Technology
    Academic Press Inc  2022
    Abstract
    Many applications, including big-data server applications, frequently encounter data misses. Consequently, they lose significant performance potential. Fortunately, data accesses of many of these applications follow temporal correlations, which means data accesses repeat over time. Temporal correlations occur because applications usually consist of loops, and hence, the sequence of instructions that constitute the body of a loop repeats many times, leading to data access repetition. Temporal data prefetchers take advantage of temporal correlation to predict and prefetch future memory accesses. In this chapter, we introduce the concept of temporal prefetching and present two instances of... 

    Spatial prefetching

    , Article Advances in Computers ; Volume 125 , 2022 , Pages 19-29 ; 00652458 (ISSN); 9780323851190 (ISBN) Lotfi Kamran, P ; Sarbazi Azad, H ; Sharif University of Technology
    Academic Press Inc  2022
    Abstract
    Many applications extensively use data objects with a regular and fixed layout, which leads to the recurrence of access patterns over memory regions. Spatial data prefetching techniques exploit this phenomenon to prefetch future memory references and hide their long latency. Spatial prefetchers are particularly of interest because they usually only need a small storage budget. In this chapter, we introduce the concept of spatial prefetching and present two instances of spatial data prefetchers, SMS and VLDP. © 2022 Elsevier Inc  

    Synthesis, and Characterization of Binuclear Platinum (IV)with Coinage Metals

    , M.Sc. Thesis Sharif University of Technology Abbasi Kamran, Ehsan (Author) ; Jamali, Sirous (Supervisor)
    Abstract
    In this research binuclear platinum(IV) complexes with coinage metals have been synthesized and characterized. the trimethyl platinum(IV) complex [PtMe3(phthalazine)3]+X- has been prepared by the reaction of [PtMe3(THF)]4 with 3 equiv. phthalazine and used as initial material. The first complex, [PtMe3(µ-(phthalazine)2Cl)PtMe3], synthesized via reaction of 2 equiv. [Pt(Me)3(Phthalazine)3] with 1 equiv. [AuClSMe2]. The second complex, [PtMe3(µ-phthalazine)3Ag][BF4], synthesized by reaction of one equiv. of each compound [Ag(CH3CN)4]BF4 and [Pt(Me)3(Phthalazine)3] And the third complex, [PtMe3(µ-phthalazine)3Cu][PF6], synthesized like second one via reaction of [Cu(CH3CN)4]PF6 and... 

    Control of continuous time chaotic systems with unknown dynamics and limitation on state measurement

    , Article Journal of Computational and Nonlinear Dynamics ; Volume 14, Issue 1 , 2019 ; 15551415 (ISSN) Kaveh, H ; Salarieh, H ; Sharif University of Technology
    American Society of Mechanical Engineers (ASME)  2019
    Abstract
    This paper has dedicated to study the control of chaos when the system dynamics is unknown and there are some limitations on measuring states. There are many chaotic systems with these features occurring in many biological, economical and mechanical systems. The usual chaos control methods do not have the ability to present a systematic control method for these kinds of systems. To fulfill these strict conditions, we have employed Takens embedding theorem which guarantees the preservation of topological characteristics of the chaotic attractor under an embedding named "Takens transformation." Takens transformation just needs time series of one of the measurable states. This transformation... 

    A new approach to extreme event prediction and mitigation via Markov-model-based chaos control

    , Article Chaos, Solitons and Fractals ; Volume 136 , 2020 Kaveh, H ; Salarieh, H ; Sharif University of Technology
    Elsevier Ltd  2020
    Abstract
    Despite that the border between chaotic and stochastic systems is exactly defined, scientists, use high dimensional chaotic dynamics to model numerous stochastic models and sometimes use stochastic models to study chaotic systems. In this paper, we have investigated chaotic systems with a stochastic approach and proposed an estimator for the chaotic system which is used to present different algorithms for chaos control, extreme event prediction and extreme event mitigation. The stochastic estimator is constructed by meshing the phase space and applying the cell mapping method (with some considerations) which provides us with a model-free approximation of the systems. The algorithms are ideal... 

    Control of continuous time chaotic systems with unknown dynamics and limitation on state measurement

    , Article Journal of Computational and Nonlinear Dynamics ; Volume 14, Issue 1 , 2019 ; 15551415 (ISSN) Kaveh, H ; Salarieh, H ; Sharif University of Technology
    American Society of Mechanical Engineers (ASME)  2019
    Abstract
    This paper has dedicated to study the control of chaos when the system dynamics is unknown and there are some limitations on measuring states. There are many chaotic systems with these features occurring in many biological, economical and mechanical systems. The usual chaos control methods do not have the ability to present a systematic control method for these kinds of systems. To fulfill these strict conditions, we have employed Takens embedding theorem which guarantees the preservation of topological characteristics of the chaotic attractor under an embedding named "Takens transformation." Takens transformation just needs time series of one of the measurable states. This transformation... 

    An overview: recent development of semiconductor/graphene nanocomposites for photodegradation of phenol and phenolic compounds in aqueous solution

    , Article Journal of Asian Ceramic Societies ; Volume 9, Issue 1 , 2021 , Pages 343-365 ; 21870764 (ISSN) Kaveh, R ; Alijani, H ; Sharif University of Technology
    Taylor and Francis Ltd  2021
    Abstract
    The development of graphene-based nanocomposites is currently the issue of enormous research interest. Recent advancements have exhibited that semiconductor/graphene nanocomposites can be purposed as a promising new category of catalysts for the heterogeneous photocatalytic treatment of wastewaters. Since semiconductor/graphene nanocomposites have been found efficient in degradation of organic pollutants, photodegradation of phenol and phenolic compounds as hazardous contaminants in aqueous solution has been most widely investigated by these aforementioned nanocomposites. In the present review, after introduction on the properties and the different synthesis methods of semiconductor/graphene... 

    Simultaneous removal of mercury ions and cationic and anionic dyes from aqueous solution using epichlorohydrin cross-linked chitosan @ magnetic Fe3O4/activated carbon nanocomposite as an adsorbent

    , Article Diamond and Related Materials ; Volume 124 , 2022 ; 09259635 (ISSN) Kaveh, R ; Bagherzadeh, M ; Sharif University of Technology
    Elsevier Ltd  2022
    Abstract
    An economical epichlorohydrin cross-linked chitosan @ magnetic Fe3O4/activated carbon nanocomposite, CH-EP@Fe3O4/AC, was successfully synthesized and used as a suitable adsorbent material for removal of a triphenylmethane cationic dye, Malachite green (MG), an anionic dye, Reactive red 120 (RR120), and Mercury ions (Hg2+) from aqueous solution. The prepared adsorbent has been characterized with Fourier transform infrared spectroscopy, X-ray diffraction, Scanning electron microscopy, Thermogravimetric analysis, Brunauer–Emmett–Teller analysis as well as Vibrating sample magnetometer. According to the result of Brunauer–Emmett–Teller isotherm, the prepared adsorbent has a specific surface area... 

    Aerodynamic Instability Modeling of a High Speed Centrifugal Compressor

    , M.Sc. Thesis Sharif University of Technology Saboori, Rozhin (Author) ; Ghorbanian, Kaveh (Supervisor)
    Abstract
    The present thesis investigates the surge phenomenon of high speed centrifugal compressors. Surge is a highly undesired condition and may cause severe damage to the machine and thus the plant. Traditionally, surge is avoided via a surge avoidance scheme wih recycle valve in discharge at the most common approach. A one dimensional technique is developed where the Greitzer lumped parameter model along with the Gravdahl one dimensional model is considered as the basis. Shaft dynamics, volume dynamics, losses, energy transfer and time lag are imbedded in the present model to improve the prediction of the compressor characteristics beyond the stability region. On the other hand, in order to... 

    Aerodynamic Design Methodology for Changing Axial Compressor Capacity

    , M.Sc. Thesis Sharif University of Technology Mofrad, Ehsan (Author) ; Ghorbanian, Kaveh (Supervisor)
    Abstract
    Axial compressor design is a very complex and expensive process. In general, for design and development of a new axial compressor, manufacturing companies usually intend to employ an existing and successful axial compressor as an starting point and modify and upgrade it. In this regard, dimensional scaling is a common method for derivative axial compressors. The goal of dimensional scaling is to get a different capacitywhile minimizing the development time and cost. In this thesis, theNASA eight stage transonic axial flow compressor is chosen as the base model for dimensional scaling to lower and upper size of its original dimension. The scaled compressor is analyzed with a quasi 2-D code.... 

    Development of a Design Tool for Restaging of Centrifugal Compressors

    , M.Sc. Thesis Sharif University of Technology Jahani, Zeinab (Author) ; Ghorbanian, kaveh (Supervisor)
    Abstract
    The purpose of this research is theoretical and numerical investigations on centrifugal compressor. A computer code has been developed to simulate single-zone and two-zone model, based on the revised formulation for real gas, using Peng-Robinson equations. Single-zone modeling, also known as meanline method, established based on 1-D equations of fluid dynamics considering ideal gas relations, empirical loss correlations, slip factors, impeller efficiency and no wake or separation regions. Considering usual significant separated regions in the gas path of impellers, two-zone (jet and wake zone) model has been developed to achieve a more reliable simulation by using fewer correlations based on... 

    Design of Heat Exchanger in Thermoacoustic Systems

    , M.Sc. Thesis Sharif University of Technology Hasibi, Iman (Author) ; Ghorbanian, Kaveh (Supervisor)
    Abstract
    In this research, the principles of design of Heat Exchangers in thermoacoustic systems are developed. The Heat Exchangers as a essential part of thermoacoustic systems, complete the thermodynamic cycle in these systems. In this thesis, principles and algorithms of design for Shell&Tube, Plate and Screen Heat Exchangers are described and these principles are validated for each kind of Heat Exchangers. Then the balance of exergy is studied in thermoacoustic systems and at the end, for every Heat Exchangers amount of exergy destruction is evaluated for oscillating and non-oscillating fluids. Based on fitness functions of exergy destruction, heat transfer area and acoustic pressure drop, Heat... 

    Modeling and Developing a Control System for Centrifigual Compressors

    , M.Sc. Thesis Sharif University of Technology Rajabi, Alireza (Author) ; Ghorbanian, Kaveh (Supervisor)
    Abstract
    Compression systems are widely used in industry. Dynamic Modeling is a necessary step in design procedure of a safe compression system. A dynamic model should be adequate and simulate dominant elements of system. One important element of industrial compression systems is downstream pipelines. In this work, a dynamic model including pipeline acoustics is developed. It is accepted that changes of working gas molecular weight can cause inception of instabilities in compression systems. The dynamic model used to study mechanisms of these instabilities. A conventional control system is modeled and tuned for the compression system. The ability of this control system to prevent such instabilities... 

    Preliminary Analysis of a Thermo Acoustic Heat Pump (THP) In Lab Scale

    , M.Sc. Thesis Sharif University of Technology Khatib, Abolfazl (Author) ; Ghorbanian, Kaveh (Supervisor)
    Abstract
    thermoacuostic heat pump (THP) is One of the most important thermoacuostic applications which is used for heat lost recovery in industrial applications and civil applications.In this project, we have a quick review on thermoacuostic theory and researches in this field. Also a thermoacuostic heat pump in a lab scale will be designed and analyzed.For achieving this goal, first, mathematical equations of thermoacuostic systems are reviewed; a thermoacuostic heat pump is designed on the base of Tijani method and final model is validated by DeltaEC software. In the next step, after investigating about laboratory equipments which is used in testing process, we generate test matrix and study about...