Loading...
Search for:
erfani-beyzaee--arash
0.155 seconds
Total 116 records
Model Predictive Control for Determining Optimal Real-time Operation of Heating (Cooling) System with Minimum Energy Consumption
, M.Sc. Thesis Sharif University of Technology ; Rajabi-Ghahnavieh, Abbas (Supervisor) ; Boroushaki, Mehrdad (Co-Advisor)
Abstract
Considering the increasing importance of energy conservation in recent decades, different technologies regarding energy system have been developed to satisfy this goal. Building section is responsible for a big portion of final energy consumption and greenhouse gasses emission around the globe. Utilizing energy consumption reduction techniques in the building sector is among the foremost solutions to achieve the energy conservation potentials in this sector which would be followed by a decline in greenhouse emissions. Considering the contribution of heating and coling systems in a building’s energy use, optimizing these systems could have a huge effect on a building’s final energy...
Hegel's ontology of power : the structure of social domination in capitalism
, Book
Cambridge University Press
2020
Structural integrity assessment of offshore jackets considering proper modeling of buckling in tubular members—a case study of resalat jacket
, Article Journal of Marine Science and Application ; Volume 21, Issue 4 , 2022 , Pages 145-167 ; 16719433 (ISSN) ; Sharif University of Technology
Editorial Board of Journal of Harbin Engineering
2022
Abstract
In the present research, results of buckling analysis of 384 finite element models, verified using three different test results obtained from three separate experimental investigations, were used to study the effects of five parameters such as D/t, L/D, imperfection, mesh size and mesh size ratio. Moreover, proposed equations by offshore structural standards concerning global and local buckling capacity of tubular members including former API RP 2A WSD and recent API RP 2A LRFD, ISO 19902, and NORSOK N-004 have been compared to FE and experimental results. One of the most crucial parts in the estimation of the capacity curve of offshore jacket structures is the correct modeling of...
Shear-flexural interaction in analysis of Reduced web section beams using VM link element
, Article International Journal of Engineering, Transactions B: Applications ; Volume 20, Issue 1 , 2007 , Pages 23-35 ; 1728-144X (ISSN) ; Kazemi, M. T ; Sharif University of Technology
Materials and Energy Research Center
2007
Abstract
Reduced web section beams in shear-yielding moment-resistant steel frames are used for energy dissipating of earthquakes. The finite element analysis indicates that failure mode of these beams are governed by the combination of shear force and flexural moment. Therefore the analysis of frames with reduced web section beams needs consideration of shear-flexural interaction in those sections. In the present paper, modeling and analysis of reduced web section beams are investigated by using a special element which is called VM link element. The elastic and inelastic shear and flexural deformations and tangential stiffnesses in this link element are considered by using the multi- surfaces...
VM link element for consideration of shear-flexural interaction
, Article 10th East Asia-Pacific Conference on Structural Engineering and Construction, EASEC 2010, Bangkok, 3 August 2006 through 5 August 2006 ; Volume 2 , 2006 , Pages 149-154 ; Kazemi, M. T ; Sharif University of Technology
2006
Abstract
A mixed shear-flexural beam element, which is called VM link element, is introduced. Dissimilar multi-surfaces in the shear-flexural space and non zero off diagonal components in flexibility matrixes are used for more realistic modeling of inelastic shear-flexural interaction. For preventing of intersecting among the yield surfaces, a new non-associated flow rule and a new kinematic hardening rule are developed. Capability of this element is examined for shear links used in eccentrically braced frames analysis for cyclic loading. It is shown that, the proposed link element is in a good agreement with the existing test results
Increasing robustness of one bit embedding spread spectrum audio watermarking against malicious attack
, Article Proceedings of the IASTED International Conference on Circuits, Signals, and Systems, Clearwater Beach, FL, 28 November 2004 through 1 December 2004 ; 2004 , Pages 69-73 ; 0889864551 (ISBN); 9780889864559 (ISBN) ; Ghaemmaghami, S ; IASTED ; Sharif University of Technology
2004
Abstract
In this paper, we change the correlation detector at receiver of spread spectrum (SS) audio watermarking to present a mechanism that prevents the system against malicious attack. The receiver of typical SS-based watermarking can only detect the watermark bit, while a pirate can send a pure signal that may incorrectly be detected as a watermarked signal. In our system we consider all conditions that we may have in SS-based watermarking system. By computing a threshold, we can detect watermark in any of two cases of having watermarked signal or pure original signal at the receiver. We reduce false alarm probability to approximately zero in our system. This mechanism, as compared to SS, comes...
Performance of Unbonded Post-Tensioned Concrete Slab Subjected to Temperature Variations
, M.Sc. Thesis Sharif University of Technology ; Kazemi, Mohammad Taghi (Supervisor)
Abstract
Tests have shown that concrete post-tensioned slab under heat condition suffer a significant reduction in stiffness and strength. Design and implementation of post-tensioned concrete slabs with large spans of industrial structures exposed to extreme variation in temperature can be possible with detailed research on its behavior under heating condition. In this study numerical modelling of PT concrete slabs with unbonded tendons under heating condition was created based on available test results in the literature. A parametric study has been carried out and the results are presented for concrete coefficient thermal expansion, thermal contact conductance between the concrete and the cables,...
Toward a hydrocarbon-based chemical for wettability alteration of reservoir rocks to gas wetting condition: implications to gas condensate reservoirs
, Article Journal of Molecular Liquids ; Volume 248 , 2017 , Pages 100-111 ; 01677322 (ISSN) ; Ghazanfari, M. H ; Sharif University of Technology
2017
Abstract
Recently, wettability alteration has been much attended by researchers for studying well productivity improvement in gas condensate reservoirs. Previous studies in this area only utilized water/alcohol based chemicals for this purpose. While, hydrocarbon nature of the blocked condensate in retrograde gas reservoirs, may motivate application of hydrocarbon based chemical agents. In this study, a new hydrocarbon based wettability modifier is introduced to alter wettability of carbonate and sandstone rocks to preferentially gas wetting condition. Static and dynamic contact angle measurements, spontaneous imbibition and core flooding tests were conducted to investigate the effect of proposed...
Design and construction of a non-linear model predictive controller for building's cooling system
, Article Building and Environment ; Volume 133 , 2018 , Pages 237-245 ; 03601323 (ISSN) ; Rajabi Ghahnaviyeh, A ; Boroushaki, M ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
This research aims to optimize a multi-zone Air Handling Unit's (AHU) energy consumption by using a Non-linear Model Predictive Control (NMPC) approach. In this paper, Genetic Algorithm (GA) and Non-linear autoregressive network with exogenous inputs (NARX) have been utilized to design NMPC for a multi-zone AHU. The NMPC problem could be divided into two main sections: internal model and the optimizer. NARX serves as the controller's internal model to predict the building's thermal dynamics. GA is then used to solve the NMPC problem and find the optimal value of the control signals at each time step. The proposed NMPC jointly minimizes energy consumption of the AHU and the deviation from the...
Application of a water based nanofluid for wettability alteration of sandstone reservoir rocks to preferentially gas wetting condition
, Article Journal of Molecular Liquids ; Volume 232 , 2017 , Pages 351-360 ; 01677322 (ISSN) ; Ghazanfari, M. H ; Sharif University of Technology
Elsevier B.V
2017
Abstract
Condensate and water banking around gas condensate wells result in vital well deliverability issues. Wettability alteration of near wellbore region to gas wetting condition is known to be the most novel and the only permanent method, to improve condensate well productivity. In this work, a water based nanofluid is used to change the wettability of sandstone reservoir rocks from strongly liquid wetting to intermediate gas wetting condition. Static contact angle measurements demonstrated significant increase of liquid phase contact angle as a result of chemical treatment with SurfaPore M nanofluid. The characteristics of SurfaPore M adsorption on sandstone rock are quantified through kinetic...
Thermal-aware Routing Algorithm in Fault-tolerant Optical Networks-on-Chip
, M.Sc. Thesis Sharif University of Technology ; Koohi, Somayyeh (Supervisor)
Abstract
During the recent years, the emerging technology of photonic, on-chip communication has been widely explored to resolve the problems of traditional electrical communication in terms of performance and power consumption. Micro-Resonator (MR) as the photonic building block for optical comunication is very sensitive to temperature and process variation. Variation of resonance wavelength of a micro-resonator as a result of temperature fluctuations causes tremendous error for optical data routing through the waveguides, and reduce the reliability of network. A temperature-aware routing algorithm enables the network to tolerate fault and continue working properly. Temperature variation of MRs is a...
About Space Time
, M.Sc. Thesis Sharif University of Technology ; Rastegar, Arash (Supervisor)
Abstract
Einstein's general theory of relativity is an admirable successful and unifier geometrical modeling among concepts of space, time and gravity. This theory along with special theory of relativity made a massive change in our physical view and this, especially in its historical context, has deep and interesting consequences in man's philosophical viewpoint which can be studied. Some parts of this thesis relates to these consequences. Some of these interesting consequences may be hidden by computional or mathematical viewpoint and often these equations do not contain enough intuition. in one part, we provide a formulizatin of Einstein's equaion that is intuitional which can be translated in...
Tropical Algebraic Geometry
, M.Sc. Thesis Sharif University of Technology ; Rastegar, Arash (Supervisor)
Abstract
Tropical algebraic geometry is a fairly new branch in geometry which is called so in honor of Brazilian mathematician Imre Simon who was pioneer of this field.The set equipped with the addition and multiplication is a semifield.Algebraic geometry objects like algebraic varieties can be defined over.Polynomials and rational functions are defined over.The functions that they define are piecewise linear and concave functions and the set of points where they are nonlinear is a tropical variety which is a concave polyhedral. Thus, tropical algebraic geometry is a piecewise linear version of algebraic geometry.Another approach to tropical algebraic geometry comes back to the works of Russian...
Evaluating the Effect of Crumb Rubber on the Fracture Properties of Asphaltic Materials Using a Standardized Composite
, M.Sc. Thesis Sharif University of Technology ; Motamed, Arash (Supervisor)
Abstract
Fatigue cracking has a major impact on the performance of flexible pavements. Many test methods have been established to evaluate and estimate the fatigue life of asphaltic materials. Most of these test methods cannot successfully examine the fatigue properties of asphaltic materials. Recent studies demonstrate that using a standardized composite, which consists of glass beads and asphalt binder, can simulate the stress states that binder experiences in the field. This research used standardized composite to investigate the effect of crumb rubber on the fracture properties of asphaltic materials. To validate the test results, the authors conducted fracture tests on the Fine Aggregate Matrix...
Novel View Synthesis Using Light Field Camera
, M.Sc. Thesis Sharif University of Technology ; Amini, Arash (Supervisor)
Abstract
In the last two decades, novel view synthesis has become increasingly important in the movie and game industries. The new generated views correspond to virtual viewpoints, where no real camera has taken snapshot. Depending on the amount of available information from the scene, different approaches have been proposed to create novel views. If the depth information is available, then by knowing camera relative motion, novel views can be constructed. The conventional cameras only record the intensity of the captured scene, and discard the depth information. In the recent concept of light field cameras, by locating an array of micro-lenses between the camera sensor and the main lens, one can...
Developing a New Method to Evaluate and Quality Control of Chip Seal
, M.Sc. Thesis Sharif University of Technology ; Motamed, Arash (Supervisor)
Abstract
Chip seal is one of the most economical pavement maintenance practice that extends pavement life. To ensure chip seal good performance several quality control methods have been developed. However, most of these methods are qualitative and only measure the stone loss under a certain number on loading. This research developed a new method for quality control of chip seal, based on the assumption that characteristics of the bond between chips and pavement surface play a key role in chip seal performance. To validate this test method, the authors used a wheel track loading test. The results from this research clearly showed that the characteristics of the bond between chips and pavement surface...
Investigating the Effect of Various Additives on the Curing Time of Chip Seal and Chip Seal Treatments in Different Climate Conditions.
,
M.Sc. Thesis
Sharif University of Technology
;
Motamed, Arash
(Supervisor)
Abstract
Recently, a new method to investigate chip seal performance has developed by a research team at Sharif University of Technology. This study investigates the effect of various additives such as CRM, SBR Latex, Hydrated Lime and Ordinary Portland Cement (OPC), on the curing time of chip seal by this method. In addition, the chip seal treatments were investigated in different climate conditions like Wet and Wet-Freeze zones. The overall performance of mixture specimens evaluated using creep loading test. In fact, the bonding properties between aggregates and surface of Hot Mix Asphalt measured. The test results were analyzed by using of the work and time parameters. These parameters were...
Brandom’s Conception of Trust
, M.Sc. Thesis Sharif University of Technology ; Abazari, Arash (Supervisor)
Abstract
A Spirit of Trust results from Brandom's thirty-year effort to give a pragmatistic reading of Hegel's Phenomenology of Spirit. In A Spirit of Trust, Brandom reformulates Hegel's arguments in the language of contemporary Analytical Philosophy and gives a unique interpretation of Hegel's key concepts. In this Thesis, we will examine one of its key concepts, namely, Trust; We will pursue the following questions: First, What is Trust? And what is its connection to other aspects of Brandom's philosophy? Second, How does Trust help us in overcoming Alienation? Third, Are Confession and Forgiveness, which are the constitutive concepts of Trust, psychologistic or normative? Fourth, What is the...
Design of Stress Absorbing Membrane Interlayer (Sami) and Overlay to Reduce Reflective Cracking
, M.Sc. Thesis Sharif University of Technology ; Motamed, Arash (Supervisor)
Abstract
Cracks or construction joints in an overlayed pavement can propagate into the overlay over time due to various factors, the most important of which are traffic and temperature loading, and cause premature failure of pavement. This propagated cracks are called reflective cracks and the phenomenon of crack propagation into the overlay is called reflective cracking. Use of stress-absorbing membrane interlayers (SAMI) is one of the ways can reduce the occurrence of reflective cracking and/or delay it. One of the most common SAMIs is an asphalt mixture consists of bitumen and aggregate layed down between the old and the veneer layers. The function of the SAMI depends on several factors such as...
An Investigation on the Effect of Filler Type and Content on the Performance of Asphaltic Materials
, M.Sc. Thesis Sharif University of Technology ; Motamed, Arash (Supervisor)
Abstract
The objective of this research is evaluating the effect of filler type and content on the characteristics of asphaltic materials. The properties of the asphalt mixture are greatly influenced by its components. As asphalt mixtures are composed of two prominent components, aggregates and binder, the change in type and contents of these materials may lead to altering the performance of asphalt mixtures. Aggregates in the asphalt mixtures are categorized into three groups based on their particle sizes: coarse aggregate, fine aggregate and mineral filler. The effect of filler on the characteristics of asphalt mixtures can be examined by changing the type and content of filler and holding the...