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A Study on the Effect of Foundation Uplift on Response of Soil-Structure Systems Using Endurance Time Method
, M.Sc. Thesis Sharif University of Technology ; Ghannad, Mohammad Ali (Supervisor) ; Esmaeil Pourestekanchi, Homayun (Supervisor)
Abstract
In recent decades, the soil-structure effect has been considered in seismic studies. Most of these researches are based on the premise that the foundation is bonded to the ground. However, several examples of structures that experienced uplift have been reported. Uplift affects the soil-structure contribution and nonlinear behavior of the structure. It seems that a parametric study should be done for the simultaneous effects of the soil-structure interaction, foundation uplift and inelastic behavior of the superstructure. Although the most accurate methods to estimate the behavior of structures is the nonlinear time history analysis, this analysis is very time consuming. The endurance time...
A new approach for solving resource constrained project scheduling problems using differential evolution algorithm
, Article International Journal of Industrial Engineering Computations ; Volume 7, Issue 2 , 2016 , Pages 205-216 ; 19232926 (ISSN) ; Sharif University of Technology
Growing Science
2016
Abstract
One subcategory of project scheduling is the resource constrained project scheduling problem (RCPSP). The present study proposes a differential evolution algorithm for solving the RCPSP making a small change in the method to comply with the model. The RCPSP is intended to program a group of activities of minimal duration while considering precedence and resource constraints. The present study introduces a differential evolution algorithm and local search was added to improve the performance of the algorithm. The problems were then solved to evaluate the performance of the algorithm and the results are compared with genetic algorithm. Computational results confirm that the differential...
Reshaping energy policy for sustainable development: Curbing Iran’s carbon emission monster via renewable energies
, Article Energy Sources, Part B: Economics, Planning and Policy ; Volume 11, Issue 9 , 2016 , Pages 830-840 ; 15567249 (ISSN) ; Maleki, A ; Sharif University of Technology
Taylor and Francis Inc
2016
Abstract
This paper formulates flow of energy from primary resources and import routes to different socio-economic sectors by making use of Long-Range Energy Alternatives Planning (LEAP) model. It presents a baseline of how Iran’s future production and consumption patterns evolve. It also seeks plausible scenario for renewable energies utilization and evaluates its mitigation potential and economic aspects. Model results indicate that exploitation of a "not-too-strict" package of renewable sources featuring 10 GW of wind and 19 GW of hydro by the end of 2035 will lead to CO2 emissions to be reduced up to an amount of 190.7 million tons in the study period. By accounting for the opportunity costs...
Development of an Analytical Framework for Evaluation of Climate Change Mitigation Policies on Iran’s Energy Security
, M.Sc. Thesis Sharif University of Technology ; Maleki, Abbas (Supervisor)
Abstract
Climate change and energy security are key drivers for future energy policy. While energy security has been a pillar of energy policy for about a century, concern about climate change is more recent and is bound to radically change the landscape of energy policy. Policy makers are now under increasing pressure to address these twin challenges: to develop cost-effective policies that will both ensure the security of our energy system and reduce greenhouse gas emissions.
Main Effort in this Project is to construct an integrated model of Iran’s energy system to serve as a policy analysis tool, by which policymakers are able to identify the future effects of a wide range of policies in...
Main Effort in this Project is to construct an integrated model of Iran’s energy system to serve as a policy analysis tool, by which policymakers are able to identify the future effects of a wide range of policies in...
Numerical Modeling of Non-Cemented and Cemented Ballast Aggregates under Triaxial Test with a Flexible Membrane Using Discrete Element Method (DEM)
, M.Sc. Thesis Sharif University of Technology ; Pak, Ali (Supervisor)
Abstract
This research deals with numerical simulation of triaxial test to determine behavior of non-cemented and cemented ballast aggregates used in base and subbase of roads and railroads. Ballast aggregates, thanks to their high strength and durability, are widely used in various fields including dam, river, road construction, and railway. One of the most widespread uses of this material is in the road body, and according to the recommendation of the British Highway Center, the materials used in the road body are well-graded gravel with the maximum size of 20 mm. Cement is also used as a corrective material to enhance the performance of road bodies. Therefore, knowing the characteristics of these...
The Impact of Information Sharing on Performance of an M/M/1 Queueing System
, M.Sc. Thesis Sharif University of Technology ; Abouee-Mehrizi, Hossein (Supervisor)
Abstract
Social media can be helpful to people in vast areas, especially in queuing systems, in the real world there is remarkably unknown information like service time, average waiting time or average queue length to customers, thus people are likely to share their experiences to posterior customers who want to use the same service. This research examines the impact of user-generated reviews, on the performances of a Markovian queuing system, we assumed that customers are not aware of the service rate, therefore they will assist next customers by writing reviews about their service time they had experienced. We intend to examine the impact of information on queueing performance such as system...
Polar codes for a quadratic-Gaussian Wyner-Ziv problem
, Article Proceedings of the International Symposium on Wireless Communication Systems ; 2013 , Pages 718-722 ; 21540217 (ISSN) ; 9783800735297 (ISBN) ; Behroozi, H ; Sharif University of Technology
2013
Abstract
In this work, we study the performance of polar codes for lossy compression of a Gaussian source with a side information at decoder; known as the quadratic-Gaussian Wyner-Ziv problem. First we extend the binary polar codes to q-ary for the Wyner-Ziv problem. We show that the nested q- Ary polar codes are optimal for this case. Then we present two polar coding schemes for the Gaussian Wyner-Ziv problem. In the first scheme, we achieve a rate above the Wyner-Ziv rate-distortion function with a gap of 0.5 bits compared with the optimal rate. This scheme utilizes a successive cancellation decoder and is optimal in weak side-information cases when the decoder side-information noise variance is...
On the performance of polar codes for lossy compression of Gaussian sources
, Article 2013 Iran Workshop on Communication and Information Theory, IWCIT 2013 ; 2013 ; 9781467350235 (ISBN) ; Behroozi, H ; Sharif University of Technology
2013
Abstract
In this work, we study the lossy source coding of a Gaussian source with polar codes. We show through two distributions on discrete alphabet, quantized approach as well as Central Limit Theorem (CLT) approach, when the alphabet size grows to infinity, polar codes can achieve the rate distortion bound for a Gaussian source. By comparing the rate of convergence on two distributions, we show that the quantized approach have a better convergence rate than the CLT approach
Evaluating the Effectiveness of Supportive Innovation Policies on New Technology-Based Firms’ Success in Reaching the Growth Stage
, M.Sc. Thesis Sharif University of Technology ; Miremadi, Iman (Supervisor) ; Vesal, Mohammad (Supervisor)
Abstract
New technology-based firms (NTBFs) are the driving force behind creating innovation and technology in countries and can play a crucial role in job creation and economic growth. These companies also facilitate technology transfer and strengthen the absorptive capacity of national innovation systems. Therefore, given the externalities of these companies, as well as their significant role in promoting innovation, governments around the world implement policies to support these firms. In Iran, the Vice President for Science and Technology has implemented policies to support NTBFs since 2013. Recently, a few studies have been carried out to evaluate these policies. However, the number of these...
Large deviation principle for semilinear stochastic evolution equations with monotone nonlinearity and multiplicative noise
, Article Differential and Integral Equations ; Volume 23, Issue 7-8 , Apr , 2010 , Pages 747-772 ; 08934983 (ISSN) ; Zangeneh, B. Z ; Sharif University of Technology
2010
Abstract
We demonstrate the large deviation property for the mild solutions of stochastic evolution equations with monotone nonlinearity and multiplicative noise. This is achieved using the recently developed weak convergence method, in studying the large deviation principle. An Itô-type inequality is a main tool in the proofs. We also give two examples to illustrate the applications of the theorems
Source Coding with Polar Codes
, M.Sc. Thesis Sharif University of Technology ; Behroozi, Hamid (Supervisor)
Abstract
Polar codes were introduced by Arikan in 2009. These codes are the first family of codes that with low encoding complexity and successive cancellation decoder, can achieve the channel capacity. Polar codes, at first were implemented for channel coding, but in 2010 performance of these codes in binary and q-ary alphabet source was studied. It is shown that these codes can perform efficiently in channel coding and source coding. On the other hand, one of the most important continuous sources are Gaussian sources. Due to the importance of Gaussian sources and good performance of polar codes, we try to evaluate the performance of these codes in Gaussian sources. Note that, these codes have...
3D Reconstruction of Soccer Players from Arbitrary Close-up View-points Using Multi-view Videos
, M.Sc. Thesis Sharif University of Technology ; Kasaei, Shohreh (Supervisor)
Abstract
In thi¬s thesis we studied 3d reconstruction of synchronized multi-view videos containing dynamic scenes of complicated deformable surfaces and fast motions, such as soccer scenes. Our pupose is to extract shape and motion of scene simultaneousely via a spacio-temporal framework. To this end, we translate our problem to a registration problem both in stereo and temporal pairs. We review 3D reconstruction methods and their related concepts like stereo correspondence and scene flow. This review is necessary to choose the best solution.In proposed solution we formulate 3d recnstruction problem as an optimization problem.Using variational framework we integrate error functional over image planes...
Sales and Marketing Cooperation: Mechanisms and Consequences
, Ph.D. Dissertation Sharif University of Technology ; Najmi, Manoochehr (Supervisor)
Abstract
Previous studies and field evidences show that creating appropriate interactions between sales and marketing departments is a challenge for many organizations. The main objective of this research is to develop and elaborate a conceptual framework in which "cooperation mechanisms" between sales and marketing and it’s "consequences" determined and provide an explanation that shows how configuration of sales and marketing relationship affects its consequences. The results show that "organizational ambidexterity" is the core consequence in proper architecture of the relationship between sales and marketing. In the strategy literature, combination of the dual capabilities of exploration and...
Study of Solutions for Skin Temperature Reduction in Process Fired Heaters
, M.Sc. Thesis Sharif University of Technology ; Farhadi, Fatholah (Supervisor)
Abstract
Fired heaters are large and complex items used in process plants. Tubular furnaces used mainly in chemical, petrochemical, and refinery process plants. For many process plants, the fired heater performance will determine process unit run-length. High tube metal temperature and coking in the process-fired heaters is one of the serious problems of process plants. Coke forms because the oil in tubes is no longer thermally stable at the operating conditions. Oil film temperature in the inside wall of tube somewhere that, process fluid has highest temperature and lowest velocity. Therefore, process fluid peak film temperature will determined rate of coke formation. This temperature is dependent...
An efficient power-aware VM allocation mechanism in cloud data centers: a micro genetic-based approach
, Article Cluster Computing ; 2020 ; Izadi, M ; Ghobaei Arani, M ; Sharif University of Technology
Springer
2020
Abstract
Efficiency in cloud servers’ power consumption is of paramount importance. Power efficiency makes the reduction in greenhouse gases establishing the concept of green computing. One of the beneficial ways is to apply power-aware methods to decide where to allocate virtual machines (VMs) in data center physical resources. Virtualization is utilized as a promising technology for power-aware VM allocation methods. Since the VM allocation is an NP-complete problem, we use of evolutionary algorithms to solve it. This paper presents an effective micro-genetic algorithm in order to choose suitable destinations between physical hosts for VMs. Our evaluations in simulation environment show that...
Effects of carbon sources in production of PHB(poh-p-hydroxybutyric acid)by Ralstonia eutropha
, Article CHISA 2006 - 17th International Congress of Chemical and Process Engineering, Prague, 27 August 2006 through 31 August 2006 ; 2006 ; 8086059456 (ISBN); 9788086059457 (ISBN) ; Yaghmaee, S ; Hamedi, J ; Sharif University of Technology
2006
Technical, Economic and Environmental Assessment of Alternative Vehicles Instead of Gasoline in Mega Cities (Case Study: Tehran)
, M.Sc. Thesis Sharif University of Technology ; Abbaspour, Majid (Supervisor)
Abstract
Today, the increase in greenhouse gases and the accumulation of thesegases in the atmosphere has caused a destructive environmental impact. Transportation systems in the country consume 25 % of the energy, which isalso the main cause of air pollution in addition to the imposition of fuelconsumption and fuel imports this has led to the design and deployment of vehicles with new technologies, necessity and importance that hybridvehicles is one of the new technologies. Considering that the average speedin road traffic is low and internal combustion engines have lower efficiencyand higher emissions, the hybrid vehicle reduces the current costs (fuelconsumption) and external costs (air pollution)...
Model for Evaluation of Optimal Allocation of Natural Gas Resources in Iran
, M.Sc. Thesis Sharif University of Technology ; Saboohi, Yadollah (Supervisor)
Abstract
Structural changes in the energy sector, including the need to diversify sources of energy supply, security of supply, energy consumption growth in developing countries, rising oil prices and the exhaustibility of fossil fuel reserves, environmental issues, increased consumption of petrochemical products etc., has led to increased share of natural gas in primary energy supply. Iran has a wide range of options to use natural gas endowment. The present research aims to develop a model for optimal allocation of natural gas to various applications.The gas distribution system is modeled in the present study. Technical onstraints together with economic characteristics are considered in the model....
Simulation and Control of Solid Oxide Fuel Cell
, M.Sc. Thesis Sharif University of Technology ; Pishvaie, Mahmoud Reza (Supervisor)
Abstract
The advent of maturing fuel cell technologies presents an opportunity to achieve significant improvements in energy conversion efficiencies at different scales and environmental conservation simultaneously. This work deals with modeling, simulation and control of planar solid oxide fuel cell with internal reformer. The presented model is based on conservation laws (mass, energy, and momentum), besides an electrochemical model with all sorts of voltage losses (ohmic losses, activation overpotentials, and concentration overpotentials). Methane steam reforming, water-gas shift reaction, and hydrogen oxidation are the main reactions in this modeling scheme. The obtained governing equations lead...
Energy planning and policy making; The case study of Iran
, Article Energy Sources, Part B: Economics, Planning and Policy ; Volume 11, Issue 8 , 2016 , Pages 682-689 ; 15567249 (ISSN) ; Vakili, A ; Eshraghi, H ; Hamidinezhad, A ; Naseri, I ; Sharif University of Technology
Taylor and Francis Inc
2016
Abstract
Due to the limited resources of fossil fuels, energy supply–demand management and planning especially in the supply-side of the energy system have increasingly become very important. This article assesses Iran’s energy system in order to find the main causes of the considerably high energy intensity in the country compared with similar economies in size and production. Accordingly, fundamental policies and strategies are proposed in order to manage the recognized bottlenecks. The conclusions suggest strongly that not only the fossil-based energy system, but also incompatible patterns of production and consumption in the reference energy system as well as the use of conventional technologies...