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    The Course of Martin Heidegger’s Notion of Science in His Early Thought,Based on Works Preceding Being and Time

    , M.Sc. Thesis Sharif University of Technology Heshmati, Ata (Author) ; Sefidkhosh, Meysam (Supervisor)
    Abstract
    In this research, first of all, the main question of Heidegger and his epoch is investigated. If we read Heidegger along the tradition of German philosophy, then it is perceived that the problem of science is the most central subject matter standing against Heidegger. My question is this: how Heidegger reaches to this existential phenomenological view about science. Regarding that, by giving a coherent narration about a crucial problem called 'the crisis of science', in the first chapter I gave a short view to philosophies preceding Heidegger, some important of which is Dilthey's philosophy of life, phenomenology of Husserl, and south-west school of neo-Kantianism. The second chapter... 

    Analysis and evaluation of machine learning applications in materials design and discovery

    , Article Materials Today Communications ; Volume 35 , 2023 ; 23524928 (ISSN) Golmohammadi, M ; Aryanpour, M ; Sharif University of Technology
    Elsevier Ltd  2023
    Abstract
    Machine Learning (ML) appears to have become the main and foremost approach to both tackle the hurdles and exploit the opportunities of The Information Age. We present our analytical review of the past years applications of the developed ML models in Materials Science. We begin our analysis by highlighting the similarities and the basic difference between Machine Learning and Screening approaches, and focus our work on direct ML applications only. The general ML procedure to develop a successful ML model for materials is illustrated and explained. We also present charts and tables summarizing the relevant literature works into categories based on ML techniques, materials classes, and... 

    A framework for multi-objective optimisation of 3D part-build orientation with a desired angular resolution in additive manufacturing processes

    , Article Virtual and Physical Prototyping ; Volume 14, Issue 1 , 2019 , Pages 19-36 ; 17452759 (ISSN) Golmohammadi, A. H ; Khodaygan, S ; Sharif University of Technology
    Taylor and Francis Ltd  2019
    Abstract
    In additive manufacturing processes, the part build orientation (PBO) is one of the most important factors that can affect the characteristics of the quality product such as the amount of support structure and the surface roughness. In most previous methods, the optimal PBO cannot be determined with high precision and accuracy in 3D space. In this paper, to find the precise and accurate optimal PBO with a desired angular accuracy, a new Taguchi-based method, called the Zooming-Taguchi method, is proposed. The proposed simulation-based method can precisely find the optimal PBO in absence of the noise effects. In order to find the optimal PBO with the desired angular resolution, the zooming... 

    Explaining Moral Role of Artifacts With Regards to Value Laden Theory of Technology

    , M.Sc. Thesis Sharif University of Technology Hosseinpour, Hesam (Author) ; Sefidkhosh, Meysam (Supervisor) ; Taghavi, Mostafa (Supervisor)
    Abstract
    In this thesis we review different approaches to the theory of value laden technology and realize that there are at least two major ideas about this. Some philosophers believe that technology is not a mere instrument and has a value laden nature. In contrast some others count technology as something neutral which contains no social or moral value. After explaining this ideas, in the second chapter we examine different models which explain the relation between technology and moral and social values and show how this values can contribute in design and use of technologies. In chapter three we talk about different methods used to steer technology in a desirable way which is in accordance with... 

    Toward low-salinity waterflooding predictive capability development in carbonates for fast screening of oil-brine-rock candidates

    , Article Journal of Petroleum Science and Engineering ; Volume 221 , 2023 ; 09204105 (ISSN) Golmohammadi, M ; Mahani, H ; Ayatollahi, S ; Sharif University of Technology
    Elsevier B.V  2023
    Abstract
    Despite numerous studies on the low-salinity waterflooding (LSWF) technique, a robust predictive capability has not yet been established. Predictive capability development is essential to reduce costs and time during the early screening or prioritization of candidate fields for LSWF in the opportunity realization process (ORP). This study aims at proposing a set of screening methods that offer the best LSWF predictive capability for various crude oil-brine-carbonate rock systems. In this regard, the robustness of different methods for predicting oil recovery factor (RF) from core-scale spontaneous imbibition (SI) experiments in carbonate rocks was investigated here. The relevant small-scale... 

    Non-line-of-sight error mitigation technique for wireless localization in micro-cell networks

    , Article 2011 4th IFIP International Conference on New Technologies, Mobility and Security, NTMS 2011 - Proceedings, 7 February 2011 through 10 February 2011, Paris ; 2011 ; 9781424487042 (ISBN) Dehghani, H. L ; Shadi, K ; Golmohammadi, S ; Sharif University of Technology
    2011
    Abstract
    Non Line of Sight (NLOS) propagation is a challenging issue which cause large errors in wireless localization systems. NLOS is especially a dominant source of errors in metropolitan area wireless networks like cellular ones. We discuss our algorithms within cellular network terminology. This paper contributes two novel algorithms. The first algorithm is to extract the NLOS state of base stations and the second one is a correction algorithm to enhance the measurements accuracy. Our introduced algorithms can easily operate with other wireless localization algorithms and reduced NLOS error. These algorithms are proposed for network-based localization because of the amount of calculation  

    A new pipeline implementation of an adaptive IIR filter for noise reduction application

    , Article IEEE International Symposium on Communications and Information Technologies: Smart Info-Media Systems, ISCIT 2004, Sapporo, 26 October 2004 through 29 October 2004 ; Volume 1 , 2004 , Pages 577-581 ; 0780385934 (ISBN) Golmohammadi, A ; Manzuri, M. T ; Ayat, S ; Sharif University of Technology
    2004
    Abstract
    the parallel form in adaptive HR filtering is an efficient realization that provides robust stability monitoring with less complexity than that of the direct form. This paper presents an implementation of two line parallel structure employing a real orthogonal transform and real coefficients second-order section as sub filters on FPGA. Architecture that is implemented is in pipeline fashion and it is independent from its building blocks and they may have its own implementation or in other system numbering. In the last section, we compared throughput of our architecture with a Ti DSP (TMS320C3x/4x), the results show that this architecture works better than the DSP  

    On the Topological Entropy of Geodesic Flows

    , M.Sc. Thesis Sharif University of Technology Reshadat, Zahra (Author) ; Razvan, Mohammad Reza (Supervisor) ; Nassiri, Meysam (Supervisor)
    Abstract
    Let M be a connected, compact, Riemannian manifold. Geodesic flow is a flow on the unit tangent bundle of M . This flow can be studied in dynamics prespective. for example entropy or complexity of the geodesic flow. in this thesis we will follow methods of entropy estimation or computing for geodesic flow. we will follow the method of anthony manning and Ricardo Mañe for proving such result. Maning present two results linking the topological entropy of the geodesic flow on M. we expalin how he find exponential growth rate volume of balls in universal cover as a lower bound for topologycal entropy. another theorem , Mañe represent the equlity between exponential growth rate of avrage of... 

    Classification of Partial Hyperbolic Diffeomorphisms on 3-manifolds

    , M.Sc. Thesis Sharif University of Technology Tahuri Turki, Ata (Author) ; Safdari, Mohammad (Supervisor) ; Nassiri, Meysam (Supervisor)
    Abstract
    In this dissertation, we will study partially hyperbolic diffeomorphisms. First, we are going to introduce partially hyperbolic diffeomorphisms and construct some examples. One of the important questions in the study of partially hyperbolic diffeomorphisms is their classification problem, which provides a deeper understanding of manifolds and also of partially hyperbolic diffeomorphisms themselves. We will go through this problem by examining Hammerlindl, Potrie’s [1]’s work. They have proved that a partially hyperbolic diffeomorphism on a 3-manifold with a virtually solvable fundamental group, that has no periodic torus tangent to contraction-center or expansion-center, is dynamically... 

    A compact model for predicting road traffic noise

    , Article Iranian Journal of Environmental Health Science and Engineering ; Volume 6, Issue 3 , 2009 , Pages 181-186 ; 17351979 (ISSN) Golmohammadi, R ; Abbaspour, M ; Nassiri, P ; Mahjub, H ; Sharif University of Technology
    2009
    Abstract
    Noise is one of the most important sources of pollution in the metropolitan areas. The recognition of road traffic noise as one of the main sources of environmental pollution has led to develop models that enable us to predict noise level from fundamental variables. Traffic noise prediction models are required as aids in the design of roads and sometimes in the assessment of existing, or envisaged changes in, traffic noise conditions. The purpose of this study was to design a prediction road traffic noise model from traffic variables and conditions of transportation in Iran. This paper is the result of a research conducted in the city of Hamadan with the ultimate objective of setting up a... 

    The non-linear effect of oil polarity on the efficiency of low salinity waterflooding: A pore-level investigation

    , Article Journal of Molecular Liquids ; January , 2021 ; 01677322 (ISSN) Golmohammadi, M ; Mohammadi, S ; Mahani, H ; Ayatollahi, S ; Sharif University of Technology
    Elsevier B. V  2021
    Abstract
    Oil polarity is an important property impacting the efficiency of low salinity waterflooding (LSWF). It directly affects fluid/fluid and rock/fluid interactions, controlling the interfacial properties and forces. However, the current findings in the literature on the effect of concentration of polar components on oil recovery by LSWF are contradictory. Therefore, the main objective of this paper is to investigate how the type of non-polar fractions and the concentration of acidic polar oil constituents change the trapped oil saturation at the pore-scale during LSWF. In this regard, we conducted a series of microfluidics LSWF experiments in both secondary and tertiary modes, using clay-free... 

    The non-linear effect of oil polarity on the efficiency of low salinity waterflooding: A pore-level investigation

    , Article Journal of Molecular Liquids ; Volume 346 , 2022 ; 01677322 (ISSN) Golmohammadi, M ; Mohammadi, S ; Mahani, H ; Ayatollahi, S ; Sharif University of Technology
    Elsevier B.V  2022
    Abstract
    Oil polarity is an important property impacting the efficiency of low salinity waterflooding (LSWF). It directly affects fluid/fluid and rock/fluid interactions, controlling the interfacial properties and forces. However, the current findings in the literature on the effect of concentration of polar components on oil recovery by LSWF are contradictory. Therefore, the main objective of this paper is to investigate how the type of non-polar fractions and the concentration of acidic polar oil constituents change the trapped oil saturation at the pore-scale during LSWF. In this regard, we conducted a series of microfluidics LSWF experiments in both secondary and tertiary modes, using clay-free... 

    Concurrent optimization of surface roughness, build time, and mechanical properties of additively manufactured product in terms of part build orientation

    , Article Progress in Additive Manufacturing ; Volume 8, Issue 6 , 2023 , Pages 1455-1471 ; 23639512 (ISSN) Darvishi, I ; Khodaygan, S ; Mohammadi, K ; Golmohammadi, A ; Sharif University of Technology
    Springer Science and Business Media Deutschland GmbH  2023
    Abstract
    With the increasing tendency to use the Additive manufacturing (AM) process and especially the Selective laser melting (SLM), improving the properties of the AM part becomes essential. Among the governing parameters for producing an AM part, part build orientation (PBO) is the most important one that can improve the properties by an appropriate adjusting. In this study, the surface roughness, build time, and mechanical properties of AM part are optimized and the results will be selected based on each objective function (OF) importance. To achieve this purpose, the OF for each property is derived from the literature. Then the OFs meta-modeled through the Kriging method and sample points of... 

    Strictly Toral Dynamics

    , M.Sc. Thesis Sharif University of Technology Talebi, Amin Sadat (Author) ; Esfahanizadeh, Mostafa (Supervisor) ; Nassiri, Meysam (Supervisor)
    Abstract
    This dissertation deals with nonwandering (e.g. area-preserving) homeomorphisms of the torus which are homotopic to the identity and strictly toral, in the sense that they exhibit dynamical properties that are not present in homeomorphisms of the annulus or the plane. This includes all homeomorphisms which have a rotation set with nonempty interior. There are two types of points: inessential and essential. It is known that the set of inessential points Ine(f ) is a disjoint union of periodic topological disks ("elliptic islands"), while the set of essential points Ess(f ) is an essential continuum, with typically rich dynamics ("the chaotic region"). One of the key results in this context is... 

    Fabrication of MEA based on sulfonic acid functionalized carbon supported platinum nanoparticles for oxygen reduction reaction in PEMFCs

    , Article RSC Advances ; 2015 , Pages 85775-85784 ; 20462069 (ISSN) Gharibi, H ; Yasi, F ; Kazemeini, M ; Heydari, A ; Golmohammadi, F ; Sharif University of Technology
    Royal Society of Chemistry  2015
    Abstract
    The Nafion ionomer affects the efficiency of the platinum (Pt) catalyst by blocking the active sites thereby restricting the gas permeability of the catalyst layer; but, there is a limitation in the quantity of Nafion ionomer that needs to be added without affecting the cell performance. Sulfonation of carbon-supported catalysts as mixed electronic and protonic conductors has been reported to be an efficient way to increase the triple-phase boundaries. In order to improve the utilization and activity of cathodic catalysts in the oxygen reduction reaction (ORR), Pt nanoparticles were loaded on a mixture of Vulcan XC-72R and MWCNTs, which were functionalized in a mixture of 96% sulfuric acid... 

    The effect of microthread design on magnitude and distribution of stresses in bone: a three-dimensional finite element analysis

    , Article Dental Research Journal ; Volume 15, Issue 5 , 2018 , Pages 347-353 ; 17353327 (ISSN) Golmohammadi, S ; Eskandari, A ; Movahhedy, M. R ; Shirmohammadi, A ; Amid, R ; Sharif University of Technology
    2018
    Abstract
    Background: The researches regarding the influence of microthread design variables on the stress distribution in bone and a biomechanically optimal design for implant neck are limited. The aim of the present study is to compare the effect of different microthread designs on crestal bone stress. Materials and Methods: Six implant models were constructed for three-dimensional finite element analysis including two thread profile (coarse and fine) with three different lengths of microthreaded neck (1 mm, 2 mm, and 3 mm). A load of 200 N was applied in two angulations (0° and 30°) relative to the long axis of the implant and the resultant maximum von Mises equivalent (EQV), compressive, tensile,... 

    Designing IoT-based Video/Audio Processing Systems

    , M.Sc. Thesis Sharif University of Technology Golmohammadi, Zahra (Author) ; Gholampour, Iman (Supervisor) ; Haj Sadeghi, Khosrou (Supervisor)
    Abstract
    The use of IoT-based technologies is expanding in many areas today. The use of audio and video processing in IoT systems has been used as an alternative to human operators by increasing power and reducing processing costs. Due to the large volume of audio and video data and bandwidth limitations, complete data transfer to cloud processing servers is not cost-effective in terms of efficiency and energy consumption. As a result, the solution that has provided good results is to discharge these device tasks to the available clouds. In other words, the capacity of resources in the environment can be used to optimize the total latency of the system and energy consumption. In this dissertation, we... 

    Stationary Measures on Homogeneous Spaces

    , M.Sc. Thesis Sharif University of Technology Rajabzadeh, Hesameddin (Author) ; Haji Mirsadeghi, Mir Omid (Supervisor) ; Nasiri, Meysam (Supervisor)
    Abstract
    Let be a sub-semigroup of SL(d;Z) which acts strongly irreducible on Rd, i.e. there is not any invariant finite union of nontrivial proper subspaces of Rd. acts on Td by homeomorphisms. We will show that under these assumptions every infinite invariant subset of Td under the action of is dense in Td. For instance, if x is a point in Td which is not rational, then x = Td. In this thesis, we will follow the method of Y. Benoist and J.F. Quint for proving such results. Their method is to prove some kind of rigidity for the stationary measures for the action of on Td. Actually, every atomless stationary measure is the lebesgue measure on Td which is invariant under all the elements of... 

    Buckling Analysis of Reinforced Composite Conical Shells under Axial Compressive Load using GDQ Method

    , M.Sc. Thesis Sharif University of Technology Gholami, Peyman (Author) ; Kouchakzadeh, Mohammad Ali (Supervisor) ; Shakouri, Meysam ($item.subfieldsMap.e) ; Noghabi, Mohammad ($item.subfieldsMap.e)
    Abstract
    The object of this study is to determine the buckling load of reinforced composite conical shells under axial compression. . Shells are reinforced by stringers and rings and the boundary conditions are assumed to be simply supported. At first the equilibrium equations are obtained using the first order shear deformation theory (FSDT), smeared stiffener technique and principle of minimum potential energy. In the following, the resulting equations which are the system of five variable coefficient partial differential equations in terms of displacement components are investigated by generalized differential quadrature method (GDQM). Finally the standard eigenvalue equation is formed and the... 

    Investigation of Low Salinity Waterflooding Predictive Capability and the Development of a Tool for Screening Candidates

    , M.Sc. Thesis Sharif University of Technology Golmohammadi, Meysam (Author) ; Mahani, Hassan (Supervisor) ; Ayatollahi, Shahab (Supervisor)
    Abstract
    Among different enhanced oil recovery (EOR) methods, low salinity waterflooding (LSWF) has been attractive to researchers because of its relative simplicity and lower environmental problems compared to other conventional EOR methods. Numerous researchers have attempted to find the main cause of the low salinity effect (LSE). According to previous studies, several experimental techniques have been proposed for predicting LSE and screening potential field candidates. However, there is a lack of a systematic investigation of all (or even some of) the methods to compare and determine their LSE predictive capability. Predictive capability development is essential because it saves costs and time...