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multiobjective-optimization
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Simulation and Multi-Objective Optimization of a Solar Micro CCHP Using Intelligent Techniques
, M.Sc. Thesis Sharif University of Technology ; Boroushaki, Mehrdad (Supervisor)
Abstract
Today, due to the scarcity of fossil energy resources, security of energy supply, and increasing environmental concerns, we need to develop new technologies to promote energy-saving and reduce greenhouse gas emissions. One of the suitable options for this purpose is to use the simultaneous production of electric power, cooling, and heating. Meanwhile, trigeneration systems that provide part of their energy needs from the sun, due to the free solar energy source and low environmental impact, can be an ideal technology for clean and safe scattered production. The present study has suggested a trigeneration system of cooling, heating, and power generation based on the organic Rankin cycle and...
Effective Optimization of Oil Production by Waterflooding
,
Ph.D. Dissertation
Sharif University of Technology
;
Pishvaie, Mahmoud Reza
(Supervisor)
;
Khorasheh, Farhad
(Supervisor)
;
Salahshour, Karim
(Supervisor)
;
Kharrat, Riyaz
(Supervisor)
Abstract
Reservoir lifetime optimization is an important issue. The policies that are used for maximum production using optimization methods become challenging in the presence of uncertainty. Robust Optimization (RO) method is a technique to deal with uncertainty. Because of insufficient data, uncertainty is an inherent characteristic of reservoir model. This leads to inexact solutions of an optimization problem. Also, design based on uncertainty in economic parameters, especially uncertain oil price is a challenging issue. Taking the uncertainty explicitly is a solution when there is no measurement available. To take into account uncertainty several possible values (realizations) for the uncertainty...
Optimal Design and Operation of Energy Supply Systems of Energy Efficient Greenhouses Based on Dual Stage Multi-objective Optimization
, Ph.D. Dissertation Sharif University of Technology ; Roshandel, Ramin (Supervisor) ; Hellweg, Stefanie (Co-Supervisor)
Abstract
The purpose of this research is developing an analytical and decision-making tool that examines the interactions between greenhouse energy demand and yield production. Greenhouseholders can use the analytical tool to design and operate existintg and newly built greenhouses in an optimal way. Becides, the decision making tool helps planners and policymakers to improve the performance of greenhouses and extend greenhouse cultivation with respect to their economic or environmental objectives.In order to develop this decision making tool, existing models for greenhouses have been investigated and various algorithms have been combined to develop an integrated energy demand-plant growth model. The...
Optimization of Service Composition Problem in Multi-cloud Manufacturing Environment
, M.Sc. Thesis Sharif University of Technology ; Houshmand, Mahmoud (Supervisor)
Abstract
Technological progress, complexity in costumers’ needs and distributed resources make extreme competition in business environment. It produces some novel concepts. In this research, we concentrate on cloud manufacturing which was generated by using cloud computing concepts and focuses on resources sharing between various manufacturers. One of key problems in this field is service composition. In this work, I have proposed a mathematical model with binary variables for service composition problem in multi-cloud manufacturing environment. In this model, I’ve considered for qualities of services (cost, time, energy, reliability) as objective functions. Cost and time functions include the cost...
Sustainable Usage of Fly ash as Stabilizer in Rammed Earth Structures
, M.Sc. Thesis Sharif University of Technology ; Toufigh, Vahab (Supervisor)
Abstract
Rammed earth (RE) is an eco-friendly building material and has been capturing special attention among researchers. Many of the recently studied RE additives are extremely resource- and energy-consuming. On the other hand, the usage of fly ash (FA), which is a sustainable replacement for cement, has been scarcely investigated in RE construction. In this paper, an experimental investigation was performed on the physical and mechanical properties of RE materials stabilized with the combination of cement and alkali-activated FA. This scrutiny consists of density measurements, pulse velocity tests, unconfined compression tests, and direct shear tests. Additionally, the carbon dioxide emission and...
Comprehensive Optimization and Design a Telecom Charger with Wide Band Gap Devices
, M.Sc. Thesis Sharif University of Technology ; Tahami, Farzad (Supervisor) ; Nasiri-Gheidarik, Zahra (Co-Supervisor)
Abstract
Nowadays high efficiency and power density are desired for designing a power electronic converter. Technology advances in power semiconductor devices, makes it possible to design converters for operation in higher frequencies to reduce size of the converters. As the frequency is increased, switching losses and temperature is also increased, so designing a converter for high frequency operation needs some tradeoffs. LLC resonant converter as a promising solution for battery chargers has ability to adjust its output voltage during Constant Current and Constant Voltage modes. However, its operation mode would change based on switching frequency change. Therefore, for efficiency-oriented...
A Multi-objective Model Predictive Control Approach to the Energy Trading Problem in Vehicle-to-Grid System
, M.Sc. Thesis Sharif University of Technology ; Haeri, Mohammad (Supervisor)
Abstract
Electric vehicles (EVs) will be used rampantly in future transportation system. Although the uncontrolled charging of these EVs will be threatening for the stability and sustainability of the grid, a well-suited energy trading policy may provide a number of beneficial services to the grid as well as preserving the sustainability of the system along with heightening the performance of operation. In this paper, by taking advantage of block rate tariff, a wholesale pricing policy is introduced. A multi-objective approach is utilized to address the cost reduction and load levelling services, concurrently, in order to guarantee the profits of the both the grid and EVs. Due to the high...
A Model to Integrate Supply and Production in a Sustainable Supply Chain
, M.Sc. Thesis Sharif University of Technology ; Najafi, Mehdi (Supervisor)
Abstract
Financial benefits are no longer the only decision makers’ criteria and they consider environmental and social merits due to the modern nature of management and international competing. As a result, sustainable supply chain management (SSCM) rises noticeably in popularity among academics for researching on it and industrialists for applying it. Having reviewed respective researches, The SSCM is addressed by an integrated approach in this rsearch for selecting green suppliers and finding optimal production plan in two phase. In first phase, thank to related literature, a framework including environmental criteria is purposed for evaluating suppliers by Analytic network process method (ANP)....
Optimal Design of Tolerances in the Non-rigid Assemblies under the Thermal Impact
, M.Sc. Thesis Sharif University of Technology ; Khodaygan, Saeed (Supervisor)
Abstract
Tolerance allocation in the recent mechanical assembly is significant because it straightly affects product performance and cost. Loose tolerances may cause the quality defect while tight tolerances can increase the cost. Thermal effects and the temperature gradients are one of the factors that caused changes in the size and geometry of the components during the performance of mechanical assemblies. This thesis proposes a new approach for tolerance design considering the thermal effects, to achieve lower manufacturing cost and good product quality. Finite element analysis is used to determine the deformation of components in an assembly. The neural network is trained using experimental...
Waste Load Allocation in Rivers by Means of the Game Theory Case Study: Dez river
, M.Sc. Thesis Sharif University of Technology ; Abrishamchi, Ahmad (Supervisor) ; Arhami, Mohammad (Supervisor)
Abstract
Nowadays, by development of technology and population, rivers have been faced environmental issues. In one hand, due to the several factors that can affect rivers pollution, it is not easy to propose a comprehensive solution for the above mentioned issues, while, on the other hand, it is necessary to address and resolve some of these issues as soon as possible. Considering rives as a system, there are lots of economic, political and quite a few other factors which try to change the condition to their own interest. In order to find a solution that satisfies all the effective parameters up to a certain limit, a mathematical tool, called the Game theory method, is utilized. In this research, we...
Expansion Planning of Urban Gas & Electricity Infrastructures Considering Grid Interoperability
, M.Sc. Thesis Sharif University of Technology ; Rajabi Ghahnavieh, Abbas (Supervisor) ; Moeini Aghtaee, Moein (Co-Supervisor)
Abstract
The present work has proposed an integrated methodology for combined gas & electricity distribution network expansion planning, which considers network expansion constraints (substation installation, feeder/pipeline installation, etc), load growth, and conversion technologies. The planning aims to determine the optimal reinforcement of existing energy network to meet the load growth in the planning horizon. To take the advantages of new technologies, CHP, fuel cell, & microturbine have been included in the problem.This paper employs gravitational search algorithm (GSA) to solve multi-objective problem, including minimization of cost, voltage drop, & pressure drop. GSA that introduced in...
A Simulation Framework for Evaluation of Multi-objective Master Production Scheduling Policy and Rolling Schedules in Make-to-order Supply Chains
, M.Sc. Thesis Sharif University of Technology ; Mahlooji, Hashem (Supervisor)
Abstract
This research studies multi-objective master production schedule (MPS) and advanced order commitment (AOC) in two-stage supply chains. Simulation-based experimental analysis evaluates the impact of environmental and MPS design factors on schedule cost and instability. The results provide insight into multi-objective MPS design considerations through rolling schedule policies. The study reveals that the manufacturer's production smoothness utility coefficient and its interaction with other experimental factors considerably impact the system's performance. In addition, it introduces a simulation framework with embedded mixed integer programming models that could be used as a framework for...
2-D Design and Optimization of Axial Flow Compressor Blade with 2-Objective Method
, M.Sc. Thesis Sharif University of Technology ; Hajilouy Benisi, Ali (Supervisor)
Abstract
Axial compressors are utilized to increase compressible flow pressure in an efficient manner where mass flow rate is high, such as aviation engines and power generation gas turbines. The flow is compressed within this machine through several stages. Each stage consists of a rotor blade row followed by a stator blade row. Energy transfer to the air is performed on the rotor by changing its velocity vector. Then, pressure is recovered from velocity by diffusion, meanwhile turning the flow direction through stator blades. These blades have been designed and optimized with various methods evolved with developing computational and manufacturing facilities. In this thesis the aerodynamic design of...
Experimental Study and Optimization of Laser Assisted Machining of Particle Reinforced Aluminum Matrix Composite
, M.Sc. Thesis Sharif University of Technology ; Movahhedy, Mohammad Reza (Supervisor) ; Khodaygan, Saeed (Co-Supervisor)
Abstract
In this thesis, the process of laser assisted machining (LAM) of metal matrix composites (MMC) is experimentally studied. The effects of process parameters (cutting speed, feed rate and depth of cut), laser parameters (laser power, laser frequency and laser beam angle), and the percentage of reinforcing particles on the tool wear and the surface roughness are investigated. Furthermore, the effects of these parameters on the built-up edge (BUE), chip shape, and workpiece temperature are explored.The experiments were performed using uncoated tungsten carbide and PCD tools under dry conditions. In order to analyze the sensitivity of the process parameters, the Plackett-Burman method was used...
Integrated Safe Design of Industrial Processes under Uncertainty
,
M.Sc. Thesis
Sharif University of Technology
;
Rashtchian, Davood
(Supervisor)
;
Sharifzadeh, Monireh
(Supervisor)
Abstract
Chemical industries are associated with hazardous chemicals and extreme operating conditions. Unsafe events can incur dramatic costs in terms of the loss of life, financial penalties and damages to the environment. Therefore, design of industrial processes which can be operated safely over a wide range of operating conditions is vital. Nevertheless, operation of industrial processes is a strong function of their design. If the process is initially poorly designed, ensuring its safe operation, if not impossible, would require costly modifications at the operational phases. This observation is due to the fact that process design decisions (e.g. design of process equipment) often have a...
Transmission Expansion Planning for Implementing Distant Wind Power Plants
, M.Sc. Thesis Sharif University of Technology ; Abbaspour Tehrani Fard, Ali (Supervisor) ; Fotuhi Firuzabad, Mahmud (Supervisor)
Abstract
Increasing the fuel cost and concerns about pollutions have facilitated the use of renewable energies. Wind power as a renewable energy has been considered as a good representative for conventional resources of electrical energy. The biggest obstacles for efficient use of the wind energy are changeability and uncontrollability in wind farm generation and to be far from the demand center. Also, conventional approaches cannot be applied to analyze the effects of this energy on power system. With increment in the penetration of the wind energy in power system, the necessity of considering its effects, especially large scale wind farm, in transmission expansion planning (TEP) studies is...
Transmission Expansion Planning in Deregulated Environments
, Ph.D. Dissertation Sharif University of Technology ; Hosseini, Hamid (Supervisor) ; Oloomi Buygi, Majid (Co-Advisor) ; Shahidehpour, Mohamad (Co-Advisor)
Abstract
This study presents a multi-objective optimization framework for transmission expansion planning in restructured electricity markets under uncertainty considerations. Deregulation of power system has introduced new objectives and requirements for transmission expansion planning problem. Also, the unbundling of electricity industry introduced new uncertainties and escalated the existing ones in network planning. Under these circumstances there is an emerging need for new planning models to cope with restructured electricity industry requirements.The conventional least-cost approaches which represent the transmission expansion planning as a single objective optimization problem could not...
Design and Analysis of Tuned Mass Damper for Reduction of Boat Roll Motion
, M.Sc. Thesis Sharif University of Technology ; Khorasanchi, Mahdi (Supervisor)
Abstract
The turbulent waves of the sea and their impact have always been one of the challenges of marine activities. Recently, with the world economic development and the boom of maritime tourism, providing comfort for the occupants of ships and boats has become one of the issues of engineering concern. Therefore, different methods are used to address this challenge. In this article, we first review these methods and then try to choose the optimal method and design a system for a relatively small boat that can compete with other methods. The method of choice is "damping mass", which has never been used to reduce the movement of boats. In this paper, by obtaining the equations governing the physics...
Design of a Heat Exchanger in an Organic Rankine Cycle Used for Engine Waste Heat Recovery
, M.Sc. Thesis Sharif University of Technology ; Morad, Mohammad Reza (Supervisor)
Abstract
In this project a heat pipe heat exchanger is designed for using in an organic rankine cycle. The cycle parameter and heat exchanger parameter are optimized at the same time. The cycle is optimized in three scenario and the results are compared. In the first scenario the objective function is the net power output of the cycle, in the second scenario the objective function is the ratio of net power output and heat transfer area(POPA) and the objective function of third optimization is POPA and exergy destruction rate(EDR). With first scenario as base case, in second scenario POPA is increased 94% and in second scenario EDR and POPA are increased 9% and 75% respectively. The results show that...
Solving Multi-objective Integer Optimization Problems by Using Benders Decomposition Method
, M.Sc. Thesis Sharif University of Technology ; Eshghi, Kourosh (Supervisor)
Abstract
Real-world decision-making problems usually have several criteria for evaluating the performance of alternatives. On the other hand, mathematical programming is a very practical tool for modeling and solving decision-making problems and multi-objective mathematical programming has high importance among researchers and managers in this field of study. However, the field of multi-objective integer programming is considered a rigorous category. Methods for solving these types of problems can be divided into three different approaches. There are few approaches and methods for solving multi-objective mixed-integer optimization problems in litreture.In this research, an extension of benders...