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zeigham-nakhaei--mohammad-hossein
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Probabilistic Comparison of Sustainability of Pavement Maintenance Programs
, M.Sc. Thesis Sharif University of Technology ; Tabatabaee, Nader (Supervisor)
Abstract
With the increasing importance of the sustainable development perspective, coupled evaluation of the environmental, economic, and functional performance of pavement maintenance programs needs to be considered. This task requires the use of data and models from different sources, which introduce uncertainty in the analysis. The use of probabilistic analysis may allow decision-makers to reach more realistic conclusions. To this end, all phases of the pavement life cycle, including material production, construction, use, and salvage at the end of life, should be considered. The effect of pavement-vehicle interaction (PVI) in the operation phase has received less attention from researchers. In...
Path Simplification Game
, M.Sc. Thesis Sharif University of Technology ; Abam, Mohammad Ali (Supervisor)
Abstract
The problem of path simplification is an important problem in computer science. With the advances in navigation and geographical information based systems, simplification and data compression have gained considerable importance. The intends to find a path with less weight than the provided path while estimating the initial path with good accuracy and simplifying the storage and process cost of path information. This problem is not only useful in Geographical Information Systems, but it also has use cases in image processing and computer graphics and has been studied a lot in computational geometry. In this research, we introduce a simplification game that models the limited version of the...
Effectiveness Evaluation of Making Natural Childbirth Free of Charge on Household Decision in Choosing Delivery Method
, M.Sc. Thesis Sharif University of Technology ; Fatemi Ardestani, Farshad (Supervisor) ; Heidarzadeh, Mohammad (Co-Advisor)
Abstract
The rate of cesarean section delivery in Iran is high and during the past 14 years, leading up to 2014, kept rising. In this regard, decreasing cesarean section rate was targeted through the healthcare reform plan, which was offered by Ministry of Health and Medical Education. This plan kicked off on May4, 2014. One of the most important proceedings of this plan was making natural childbirth to be free in all hospitals, which are under the auspices of the medical universities. According to healthcare utilization models, lower prices of healthcare services, more health centers and more accessibility to them, increase the probability of using health care services. Current study evaluated the...
The effect of soil-structure interaction on damage index of buildings
, Article Engineering Structures ; Volume 30, Issue 6 , 2008 , Pages 1491-1499 ; 01410296 (ISSN) ; Ali Ghannad, M ; Sharif University of Technology
2008
Abstract
The effect of Soil-Structure Interaction (SSI) on Park and Ang Damage Index in a Bilinear-SDOF model is investigated under seismic loading. This is done through an extensive parametric study. Two non-dimensional parameters are used as the key parameters which control the severity of SSI: (1) a non-dimensional frequency as the structure-to-soil stiffness ratio index and (2) the aspect ratio of the structure. The soil beneath the structure is considered as a homogeneous elastic half space and is modeled using the concept of Cone Models. The system is then subjected to three different earthquake ground motions as the representative motions recorded on different soil conditions. The analysis is...
The effect of soil-structure interaction on hysteretic energy demand of buildings
, Article Structural Engineering and Mechanics ; Volume 24, Issue 5 , 2006 , Pages 641-645 ; 12254568 (ISSN) ; Ghannad, M. A ; Sharif University of Technology
Techno-Press
2006
Abstract
The effect of soil-structure interaction (SSI) on hysteresis energy demand of buildings using an ensemble of alluvium site records was investigated. The structure and the soil were molded separately and then combined to constitute the soil-structure model using the sub-structure method. The key parameters effecting the response of the soil-structure system were found to be a non-dimensional frequency as a representative of structure to soil stiffness ratio; and aspect ratio of the building. It was found that the hysteric energy dissipated in a structure under an earthquake can be highly effected when the stiffness of the soil beneath the structure is altered
Mechanical Design and Fabrication of a Parallel Hybrid Vehicle Powertrain Simulator
, M.Sc. Thesis Sharif University of Technology ; Saadat Foumani, Mahmoud (Supervisor)
Abstract
In this research, the mechanical section of a reduced-scale hybrid vehicle simulator was designed and fabricated. In order to scale down the vehicle dynamics, a method based on dimensional analysis was proposed. An internal combustion engine and an electric motor were selected as power sources and then, scaling was performed, according to the specifications of the combustion engine. Afterwards, the power transmission system was designed first in concept and then in more detail. Finally, the design was manufactured and assembled. The study was made in conjunction with another study responsible for the controlling section of the work, conducted by Safabakhsh The sponsor of these two researches...
Super Hydrophobic Ni Coating on Steel by Electrodeposition Method
, M.Sc. Thesis Sharif University of Technology ; Dolati, Abolghasem (Supervisor)
Abstract
In this study, the properties of super-hydrophobic Ni coating on carbon steel including wetting behavior and corrosion resistance of Nickel coatings deposited on the steel substrate were investigated. For this purpose, Nickel coatings deposited by electrodeposition method in deferent current density (10,20,30,50, 70 mA /cm2) in bath containing 1.5 mol of ethylene de-ammonium de-chloride, 0.5 mol H3BO3, 1 mol Nicl2.6H2o and then immersed in a bath containing 0.01 mol per liter myristic acid and ethanol for 24 hours and then placed in the room temperature for 14 days. Deferent tests were used for characterization, wettability properties, corrosion behavior and morphology of Ni coatings. The...
A Reinforcement Learning Approach for Dynamic Pricing (Case Study: Iran Electrical Power Grid)
, M.Sc. Thesis Sharif University of Technology ; Shadrokh Sikari, Shahram (Supervisor)
Abstract
Population growth and the escalating use of electric devices have led to a surge in electricity demand. However, the construction of adequate infrastructure to meet this additional demand is highly expensive. To address this issue that sometimes causes power outages, dynamic pricing for electricity, a demand management technique, has gained significant importance. By employing this method, prices can be adjusted on an hourly basis, enabling consumers to regulate their consumption in response to these price fluctuations. The prices can be determined based on different objective functions. This research aims to develop a comprehensive framework for determining the optimal hourly electricity...
Combustible organic materials : determination and prediction of combustion properties
, Book
De Gruyter
2018
The Study of Eliminating Gender Gap in Iran Labor Market on Participation Rate of Married Urban Women
, M.Sc. Thesis Sharif University of Technology ; Rahmati, Mohammad Hossein (Supervisor) ; Joshaghani, Hossein (Supervisor)
Abstract
The low female labor force participation rate in the Iranian labor market relative to the global average and even to countries that do not differ significantly from the socio-economic characteristics of our country is one of the important questions of the Iranian labor market. In this study, we seek to answer the question of whether the economic participation rate of married women will increase if the gender gaps in wages, job findings and job losses among women and men are eliminated in the Iranian labor market. To answer this question using household expenditure and income data and labor force data, we show that between the two categories of occupations, in terms of the share of women's...
Crack Detection in a Rotor using Traditional Mode Shape Based Modal Analysis Methods and Experimental Evaluation
, M.Sc. Thesis Sharif University of Technology ; Mohammad Navazi, Hossein (Supervisor)
Abstract
Fatigue crack growth can have harmful effects on the reliability rotary machine. While an early warning to crack, can be used to extend the life of these expensive machines and increase reliability.Structural Vibration Condition Monitoring as a primary fault detection method, achieved to a lot amazing result and for this reason studies vibration behavior of cracked rotational shaft is a big issue for engineers of dynamic machine.In this research, first check the fault detection methods based on structural vibration condition monitoring, mode shape methods were extracted. Then by modeling rotational shaft in computer and creation of crack on it, fault detection quality of these methods have...
Investigating and Analyzing the Optimal Method for Construction of Keshavarz Metro Station on Line Three of Esfahan Urban Railway
, M.Sc. Thesis Sharif University of Technology ; Sadaghiani, Mohammad Hossein (Supervisor)
Abstract
It is important to provide an appropriate and economically method with technical and engineering considerations to stabilize excavated underground spaces. The necessity of this, especially for the construction of underground metro stations located in the cities which faces many problems, is more evident. In this research, it has been tried to introduce an optimal method according to the type of area for the construction of the underground station. In order to obtain stress and strain condition in structural elements and surface deformations due to different stages of excavating, numerical modeling in FLAC3D has been used. By examining the parameters that affect the sustainability of this...
The Effect of Increasing The Value of Natural Gas Production on Property Value, Wages, Unemployment Rate and Birth Rate in The United States of America (2000-2011)
, M.Sc. Thesis Sharif University of Technology ; Rahmati, Mohammad Hossein (Supervisor)
Abstract
In the present study, the effects of increasing the value of shale gas production, either due to increased production or price increases, have been studied on economic variables such as employment, wage, property value and the number of births. In this regard, the data for each of these variables was used at the county level in the United States of America between 2000 and 2011. In order to estimate the desired effects, counties are divided into two types of boom and non-boom counties. The findings indicate that increasing natural gas production will lead to more employment and wage growth in boom counties than non-boom counties. Also, during the period of increasing production, the value of...
Inflationary Permanent and Long-Term Positive Interest Rate Shocks
, M.Sc. Thesis Sharif University of Technology ; Rahmati, Mohammad Hossein (Supervisor)
Abstract
Co-movement between inflation and nominal interest in response to an interest rate shock, dubbed neo-fisherianism, has been the subject of contentious debate since the advent of non-inflationary ZLB environment. We design an economic model rich with banking features to understand the economic responses to permanent and long-term interest rate shocks. We find that responses to a permanent positive interest rate shock depend on the monetary authorities’ speculation of the new long-term inflation rate, with the most probable outcome being a permanent increase in inflation. Responses to a long-term positive interest rate shock depict an increase and then decrease in inflation. We also discover...
Learning Interpretable Representation of Drugs based on Microscopy Images
, M.Sc. Thesis Sharif University of Technology ; Rohban, Mohammad Hossein (Supervisor)
Abstract
In this study, we aim to learn representations from microscopic cell images that effectively capture the features of drugs affecting the cells, allowing us to identify effective drugs for treating a disease. We employ two parallel learning paths using predictive and generative models. Specifically, we have achieved a predictive model on the RxRx19a dataset that, unlike previous models, is interpretable, optimized, and robust to dras- tic changes in drug properties. Additionally, we have developed the first generative model on this dataset, which not only generates high-quality images but also discovers a meaningful latent space. This latent space divides the representation into relevant...
A new model for robust facility layout problem [electronic resource]
, Article Information Sciences, Elsevier ; Volume 278, 10 September 2014, Pages 498–509 ; Eshghi, Kourosh ; Salmani, Mohammad Hassan ; Sharif University of Technology
Abstract
The Facility Layout Problem (FLP) is the problem of locating each department in a long plant floor without any overlap between departments in order to minimize the material handling cost. The main purpose of this study is to show the effectiveness of a robust approach to solve FLP. In this study, it is assumed that the departments’ length and width are not predetermined. For modeling this kind of uncertainty, the size of each department is considered as a bounded variable and two new parameters are also introduced to implement a robust approach. Moreover, a new adaptive algorithm is designed to determine the robust layout with respect to the decision makers’ requirements. Furthermore, the...
Interaction of Parallel Tunnels; Case Study: Interaction of Towhid Tunnel and Tehran Metro line 7 Tunnel
, M.Sc. Thesis Sharif University of Technology ; Sadaghiani, Mohammad Hossein (Supervisor)
Abstract
Influence of excavating the Tehran metro line 7 tunnel on surface settlement, stresses and deformations induced in Towhid tunnel is investigated using numerical modeling. Construction of Metro tunnel as the new one must be carried out without imposing any damage to the Towhid tunnel as the existing tunnel. Towhid tunnel is a set of twin tunnels along the Chamran highway in Tehran. The tunnels were constructed using sequential excavation method and lined with cast in place reinforced concrete; on the other side metro line 7 is being constructed using 2 EPB tunnel boring machines and lined with reinforced concrete segments. This research consists of the study of the effects of pillar width,...
Pore-Scale Experimental Study of Foam/Nano-Foam Flooding to Heavy oil in Heterogeneous Five-Spot System: Stability Analysis and Displacement Mechanisms
,
M.Sc. Thesis
Sharif University of Technology
;
Ghazanfari, Mohammad Hossein
(Supervisor)
Abstract
Foam injection for enhanced oil recovery is concerned by petroleum engineers because it decreases adverse effects of fingering and gravity segregation caused by the injected fluid .Obviously foam stability is an important factor in the efficiency of this process. So investigating it is an imperative. One of the ways that less studied and can improve foam stability is using of nanoparticles. In this project effect of nanoparticles on foam stability and displacement mechanism during foam flooding has been discussed.
Study consisted of two sets of experiments. In the first part, the static foam stability in the presence of silica nanoparticles has been investigated. Also influence of...
Study consisted of two sets of experiments. In the first part, the static foam stability in the presence of silica nanoparticles has been investigated. Also influence of...
Modeling and Simulation of Miscible Flow through Fractured Porous Media Using Random Walk Method
, M.Sc. Thesis Sharif University of Technology ; Ghazanfari, Mohammad Hossein (Supervisor)
Abstract
Miscible displacement in fluid flowing through a porous medium plays an important role in many environmental and industrial applications; for instance, miscible displacements in enhanced oil recovery processes and pollutant spreading in groundwater. A large number of numerical approaches have been developed to solve the advection-dispersion equation that describes the behavior of miscible displacement in porous media. Most of these numerical models suffer from numerical dispersion. Random walk seems to be an effective method to overcome this problem especially in heterogeneous media. Here, a random walk model was developed and used for simulating miscible displacement in heterogeneous porous...
Spherical Graphite Cast iron Production from Sponge Iron
, M.Sc. Thesis Sharif University of Technology ; Ashuri, Hossein (Supervisor)
Abstract
Due to the increasing spread of metal industries and the need for raw material as feed for electric furnaces in order to produce cast iron and steel, as well as scrap deficiency and rising prices, the use of sponge iron as a substitute for scrap was considered in this project Therefore, in order to achieve the chemical analysis of the sorel ingot that is special for spherical graphite cast iron production with low manganese and chromium content, the direct reduction process was carried out using tunnel kiln method on low-manganese iron ore concentrate.After the investigation on direct reduction parameters including the saggers and coal grading,the produced sponge iron has melted in...