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A Model for optimizing railway alignment considering bridge costs, tunnel costs, and transition curves
, Article Urban Rail Transit ; Volume 5, Issue 4 , 2019 , Pages 207-224 ; 21996687 (ISSN) ; Shafahi, Y ; Hashemian, S. E ; Sharif University of Technology
Springer
2019
Abstract
Owing to wide-ranging searches (there are various alignments between two points) as well as complex and nonlinear cost functions and a variety of geometric constraints, the problem of optimal railway alignment is classified as a complex problem. Thus, choosing an alignment between two points is usually done based on a limited number of alignments designed by experts. In recent years, the study of railway alignment optimization has shown the importance of optimization and the introduction of various algorithms and their usefulness in solving different problems. It is expected that applying meta-heuristic optimization algorithms such as methods based on swarm intelligence can lead to better...
An Innovative Method to Monitor Power Production Performance of Wind Farms Using Web-GIS Technique
, M.Sc. Thesis Sharif University of Technology ; Abbaspour, Madjid (Supervisor) ; Mehdigholi, Hamid (Co-Advisor)
Abstract
Nowadays because of population growth and limitation of fossil fuels for power generation purpose, utilization of renewable energy sources has become highlighted. According to the geographical situation for use of wind energy, since some areas of Iran are in suitable conditions the manufacture of wind turbines and installation in wind farms has been under development recently. Monitoring the performance and operation of turbines and wind farms is an inevitable matter. Because of the suitable geographical location of Iran and pursuant to fair wind potential sites widespread this country, this phenomenon requires some backgrounds in many aspects to be achieved. One of the most important...
Hydropower plant site spotting using geographic information system and a MATLAB based algorithm
, Article Journal of Cleaner Production ; Volume 152 , 2017 , Pages 7-16 ; 09596526 (ISSN) ; Khanian, M ; Shamsai, A ; Sharif University of Technology
Abstract
Meanwhile with increasing demand for energy sources in the world, hydropower plants can be considered as clean energy sources for sustainable development. Hydropower plant environmental impact is almost none. They are easy to construct and operate with much lower cost in comparison with other types of power plants. Currently in Iran, Conventional methods for determining hydropower plant potent location are very complicated and do not always eventuated to the best result. This study focuses on run of river projects and proposes a new methodology to spot hydropower plan best location according to specific engineering criteria, using ArcGIS and an algorithm developed in MATLAB. An economic...
Novel minimum time trajectory planning in terrain following flights
, Article IEEE Transactions on Aerospace and Electronic Systems ; Volume 43, Issue 1 , 2007 , Pages 2-12 ; 00189251 (ISSN) ; Kosari, A. R ; Sharif University of Technology
2007
Abstract
A new methodology has been proposed to enhance inverse dynamics applications in the process of trajectory planning and optimization in terrain following flights (TFFs). The new approach uses a least square scheme to solve a general two-dimensional (2-D) TFF in a vertical plane. In the mathematical process, Chebyshev polynomials are used to model the geographical data of the terrain in a given route in a manner suitable for the aircraft at hand. The aircraft then follows the modeled terrain with sufficient clearance. In this approach the terrain following (TF) problem is effectively converted to an optimal tracking problem. Results show that this method provides a flexible approach to solve...
Forecasting Urban Groundwater Level Applying Geographical Information System (GIS) and Artificial Neural Network (ANN)
, M.Sc. Thesis Sharif University of Technology ; Abrishamchi, Ahmad (Supervisor)
Abstract
Groundwater beneath the cities is becoming an important and valuable resource. Conjunctive use of surface and groundwater is likely to become increasingly more common as urban population grows by time. Therefore, one important requirement for urban water management planning is forecasting the groundwater level fluctuations. Unfortunately less experience and information is available to evaluate the fluctuations of groundwater level in urban environment compare to the natural systems, also different processes (sources) are involved in an urban water cycle, which all together make it more complicated to study. Similar to many other megacities, there is a serious lack of hydrogeological and...
A New Representation for GIS Data Based on Vector Format
, M.Sc. Thesis Sharif University of Technology ; Vosughi Vahdat, Bijan (Supervisor) ; Bagheri Shouraki, Saeed (Co-Advisor)
Abstract
One of the important tools that we frequently use in life is the map. In every day movements we can use the maps in order to navigate and find our way. We also utilize the maps to find out more about our surrounding world. GIS is the key technology which can help us reach these goals. In GIS generally there are 2 methods for representing geographic data, these methods are Raster and Vector data representation. In this thesis our purpose is to find another way for representing GIS data by using vector format. In this new representation we can access to information which are not accessible in regular maps. So we generate a new flexible platform for GIS data. Thus in order to represent new...
Design of Optimum Railroad Alignments Using Ant Colony Optimization
,
M.Sc. Thesis
Sharif University of Technology
;
Shafahi, Yousef
(Supervisor)
Abstract
Optimum railroad alignment, which can be categorized into continuous problems, has been a conundrum for engineers because of two reasons: At the first, there is a wide variety of information that is necessary for finding optimum one. Secondly, the major costs of a railway, such as length-dependent, traffic-dependent, volume-dependent and location-dependent are affected by the numerous factors so that, it may be difficult to formulate them. In order to solve large scale continuous optimization problems, there are two approaches: firstly, such problems may be tackled with a combinatorial optimization algorithm, e.g. ant colony optimization (ACO), by the continuous range of allowed values are...
Assessing the Ecological Potential of Tehran City Using Sustainable Urban Criteria
, M.Sc. Thesis Sharif University of Technology ; Abrishamchi, Ahmad (Supervisor)
Abstract
The citizens’ dissatisfaction with the decreased life and residential care quality is increasing as a result of the rapid growth and development of cities. To find an effective solution to reduce and control these harmful effects is one of the main concerns of urban managers and planners in most countries. In this research, various ecological and sustainability criteria were selected through library-based studies and relative recognition of the region. The Maps were mostly provided through satellite imagery and some by using synoptic data collected from the official aerology website of the country, Iran. Through surveying the experts, different criteria were evaluated and based on the...
A logit-based model for facility placement planning in supply chain management
, Article International Journal of Logistics Systems and Management ; Volume 20, Issue 1 , 2015 , Pages 122-147 ; 17427967 (ISSN) ; Shnaiderman, M ; Tavana, M ; Ceder, A ; Sharif University of Technology
Inderscience Enterprises Ltd
2015
Abstract
The facility placement in supply chain management entails suppliers and consumers along with the terminals in between for distributing commodities. This study seeks to find the best terminal placement by taking into consideration the costs for both transportation and terminal construction. We call this a supplier-terminal-consumer (STC) problem and show that the STC is an NP-hard quadratic assignment problem. The NP-hard problems in real-size are proven to be intractable; hence, we develop a two-fold heuristic method for solving the STC problems. First, we identify the commodity flow by using a logit-based mathematical programming (Logit-MP) methodology based on the demand for the commodity...
Finding paths with minimum shared edges
, Article Journal of Combinatorial Optimization ; Volume 26, Issue 4 , 2013 , Pages 709-722 ; 13826905 (ISSN) ; Sack, J. R ; Zarrabi Zadeh, H ; Sharif University of Technology
Abstract
Motivated by a security problem in geographic information systems, we study the following graph theoretical problem: given a graph G, two special nodes s and t in G, and a number k, find k paths from s to t in G so as to minimize the number of edges shared among the paths. This is a generalization of the well-known disjoint paths problem. While disjoint paths can be computed efficiently, we show that finding paths with minimum shared edges is NP-hard. Moreover, we show that it is even hard to approximate the minimum number of shared edges within a factor of 2log1-εn, for any constant ε>0. On the positive side, we show that there exists a (k-1)-approximation algorithm for the problem, using...
City hazardous gas monitoring network
, Article Journal of Loss Prevention in the Process Industries ; Volume 18, Issue 4-6 , 2005 , Pages 481-487 ; 09504230 (ISSN) ; Mansouri, N ; Sharif University of Technology
2005
Abstract
In our today's societies, many dangerous chemicals are produced and transported. Due to the vast use of chemicals, more chemical accidents are taking place with huge losses. In this study a city hazardous gas monitoring network was designed to detect the dispersion of toxic and combustible gases in the primary stages. The network could cover hazardous chemical facilities, important hazardous chemical routes, warehouses and special locations which may be the targets of terrorist attacks. The network is consisted of several local networks and a central control panel complex. Each local network has a local control panel in the center and many detectors and sounders around it at distances less...
Study of the Necessity and Feasibility of ASR Method of Artificial Recharge Projects in Hamoon-Jazmoorian Basin (in IRAN)
, M.Sc. Thesis Sharif University of Technology ; Hashemian, Jamaloddin (Supervisor)
Abstract
Artificial recharge is an effective method of enhancing groundwater resources. Different methods are being used for aquifer recharge, including direct surface and subsurface method, Combined and indirect methods. Among these, direct surface methods such as flood spreading and ditch and furrow techniques are most commonly used methods. They are frequently used in Iran too, but what is disregarded herein, is the application of modern methods of artificial recharge such as ASR and ASTR. ASR and ASTR are methods of artificial recharge through injection wells/borings, in order to recharge deep-seated or those aquifers which are separated by impermeable stratum from the surface. These methods,...
A Customized Particle Swarm Method to Solve Highway Alignment Optimization Problem
, Article Computer-Aided Civil and Infrastructure Engineering ; Volume 28, Issue 1 , January , 2013 , Pages 52-67 ; 10939687 (ISSN) ; Bagherian, M ; Sharif University of Technology
2013
Abstract
Optimizing highway alignment requires a versatile set of cost functions and an efficient search method to achieve the best design. Because of numerous highway design considerations, this issue is classified as a constrained problem. Moreover, because of the infinite number of possible solutions for the problem and the continuous search space, highway alignment optimization is a complex problem. In this study, a customized particle swarm optimization algorithm was used to search for a near-optimal highway alignment, which is a compound of several tangents, consisting of circular (for horizontal design) and parabolic (for vertical alignment) curves. The selected highway alignment should meet...
Vulnerability assessment of urban groundwater resources to nitrate: the case study of Mashhad, Iran
, Article Environmental Earth Sciences ; Volume 76, Issue 1 , 2017 ; 18666280 (ISSN) ; Ataie Ashtiani, B ; Beheshti, A ; Sharif University of Technology
Springer Verlag
2017
Abstract
Groundwater vulnerability assessment of urban areas is a challenging task in the fast trend of urbanization around the globe. This study introduces a new approach for modifying well-known parameters of common vulnerability indexes to adjust them for urban areas. The approach is independent of a specific weighting system. The aquifer of Mashhad city, contaminated by domestic wastewater, is selected as a case in this study. In order to evaluate the aquifer vulnerability due to anthropogenic activities, at first, parameters of depth to groundwater, recharge, land use, and soil are modified based on their basic concepts and their influences on contamination attenuation. Then, the modified...
Using Web-GIS technology as a smart tool for resiliency management to monitor wind farms performances (Ganjeh site, Iran)
, Article International Journal of Environmental Science and Technology ; 2018 ; 17351472 (ISSN) ; Abbaspour, M ; Radfar, R ; Mohammadi, A ; Sharif University of Technology
Center for Environmental and Energy Research and Studies
2018
Abstract
Considering the wide spread locations of wind farms in Iran, it is important to develop a suitable decision support system (DSS) to fulfill proper management of wind farms. Extensive literature survey indicates that there are no integrated forms of DSS to manage a set of wind farms. The existing wind farms are performing independently, and there is no practical method for exchanging the online data. DSS can contribute to optimal operation of wind farms, operation and maintenance scheduling, pricing policy, etc. In this study, a geographic information system and RETSCREEN software were linked to the designed DSS to achieve a more suitable result. Also, a huge number of data are constantly...
Development of a Model to Investigate Energy Production Potential from Sea Applying GIS Technique
, M.Sc. Thesis Sharif University of Technology ; Abbaspour, Majid (Supervisor)
Abstract
The growing requirements for renewable energy production lead to the development of a new series of systems, including wave and tidal energy conversion systems. Due to their sensitivity and the impact of the aggressive marine environment, the selection of the most adequate location for these systems is a major and very important task. Several factors, such as technological limitations, environmental conditions, administrative and logistic conditions, have to be taken into account in order to support the decision for best location. The aim of the present study is to provide an Atlas of IRAN Offshore Renewable Energy Resources (hereafter called ‘the Atlas’) to map out wave and tidal resources...
Study and Assessment of Groundwater Vulnerability and Contamination to Nitrate: A Case Study of Mashhad City
, M.Sc. Thesis Sharif University of Technology ; Ataie-Ashtiani, Behzad (Supervisor)
Abstract
Groundwater resources in arid and semi-arid regions, which the most parts of them have not had enough surface water, is of great importance. Due to the paramount importance of these vital resources, many scholars have conducted various studies on groundwater contamination and, especially, on nitrate as the best indicator of groundwater contamination because of its ability to transport, its low absorption, and its durability in water. In this study, using qualitative methods, groundwater contamination of Mashhad aquifer was evaluated, and then in order to obtain better adjustment with urban areas, these methods were modified which resulted in better correlation with measured nitrat. Based on...
Design of Water Conveyance Systems Route Applying Satellite Images, Geographic Information System(GIS) & Genetic Algorithm
, M.Sc. Thesis Sharif University of Technology ; Shamsai, Abulfazl (Supervisor)
Abstract
To reduce construction costs selecting the optimal route for water conveyance line entails ample observation and considering all effective parameters. Some part of Aidoghmoush dam project of water conveyance line located in Azerbijan the east has been investigated in this research. First, by investigating, effective factors in determining the optimal route have been identified and then categorized into two groups of quantitative criteria(technical-economical) and qualitative criteria(environmental). Quantitative objectives include: slope, transportation system, infrastructures, fault and soil type. Qualitative objectives include: environmental considerations, land use and land cover. Because...
Offline Map-Matching for GPS Observations
, M.Sc. Thesis Sharif University of Technology ; Abam, Mohammad Ali (Supervisor)
Abstract
Location observations from Global Positioning System (GPS) loggers are an important source of data for travel behavior researchers. Using GPS, requires a receiver, a digital map and a software that matches the user logged positions to the map. Identifying the location of the GPS data points on a coded map of the transportation network is not a trivial process. There is always an error in calculating the coordinates obtained from the GPS satellites, and also the available maps are not accurate enough. As a result, map-matching always carries some errors. Thus, different algorithms to do this mapping more precisely are presented. The output of the map-matching process is the identification of...