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tahmasbi-nowtorki--koorosh
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Investigating the Challenges of Seabed Drilling in Deep Waters and Designing the Optimal Drilling Fluid
, M.Sc. Thesis Sharif University of Technology ; Ghazanfari, Mohammad Hossein (Supervisor) ; Tahmasbi Nowtorki, Koorosh (Supervisor) ; Kalhor Mohammadi, Mojtaba (Co-Supervisor)
Abstract
With the development of technology and the increase in the global need for energy, the drilling of oil and gas wells moves towards deep and ultra-deep waters, and since the drilling fluid plays an important role in the drilling operations, it requires drilling fluid with the characteristics It is a suitable function to overcome the serious challenges of drilling, including low temperature rheology and borehole heat transfer problems in these areas.The purpose of carrying out this research on the design of water-based and emulsion-based protective fluids is to use laboratory materials and equipment and conduct appropriate tests in order to evaluate the observations and tests performed in...
Trajectory control of autonomous mobile robots considering disturbance with machine learning agents
, Article Journal of the Brazilian Society of Mechanical Sciences and Engineering ; Volume 45, Issue 6 , 2023 ; 16785878 (ISSN) ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH
2023
Abstract
Mobile robots as automatic machines have the capability to move around various environments and have considered because of wide range of applications in the industrial settings. It is vital for a mobile robot to determine its errors in indeterminate conditions and provide a robust and high performance controller along with trajectory control. Hence, the research has attempted to give a learning-based controller method for wheeled mobile robots in the presence of disturbance. The proposed method, use LQR controller and the Bat algorithm based on machine learning agents to calculate and identify control errors and satisfy the stability. The wheeled mobile robot should track the reference path...
Chaos control in networked permanent magnet synchronous motor using Lyapunov-based model predictive subject to data loss
, Article Engineering Reports ; Volume 6, Issue 5 , 2024 ; 25778196 (ISSN) ; Sharif University of Technology
2024
Abstract
This study investigates the chaos control in the permanent magnet synchronous motor (PMSM) using a Lyapunov-based model predictive approach subject to data loss. PMSM, as a rich nonlinear dynamic, can demonstrate chaotic behavior when its parameters are in a certain area. Thus, the performance of the system will degrade in this condition. Moreover, in some networked applications, especially in the modern automation industry, data can be lost at the sensor-controller and controller-actuator links. It will lead the system to illustrate the chaotic behavior. Thus, by assuming a PMSM under data loss, a Lyapunov-based predictive model is applied to control the chaos in the PMSM in the presence of...
Optimization in Hub Location Allocation Problem
, M.Sc. Thesis Sharif University of Technology ; Eshghi, Koorosh (Supervisor)
Abstract
Hub location problem arises where the flow has to be routed between a set of origins and destinations, but direct links between all nodes are impossible or too costly. In these situations, e.g. transportation and communication systems, hubs serve as transshipment points to collect, transfer, and distribute the flow. In hub location allocation problem, hubs are located and non-hub nodes are allocated to them. In this thesis, two different models of capacitated multiple allocation hub location problem are discussed. In the first model, flow collection of hubs from non-hub nodes and in the second model, sum of flow collection and distribution of hubs from/to non-hub nodes is addressed. The...
Robust Facility Layout
, M.Sc. Thesis Sharif University of Technology ; Eshghi, Koorosh (Supervisor)
Abstract
Facility layout problem (FLP) is one of the classical problems that concern with planning for the placement of facilities. Two dimensional layout problem is one of the special layout problems that involves with the arrangement of facilities in non predefined shape. For solving the FLP, a number of information such as dimensions of facilities, relations between facilities, governing constrains etc., are required. But in the most research works, it has been assumed that the required information is precisely known. In this thesis, we challenge this assumption considering the size (length and width) of facilities as bounded variable parameters. In order to make the problem solvable in the sense...
Multi-service Healthcare Network Design Assuming Patients' Choice Behavior and Their Transfers Between Services
, M.Sc. Thesis Sharif University of Technology ; Eshghi, Koorosh (Supervisor)
Abstract
Efficient location of health centers is an essential decesion in healthcare strategic planning. Nowadays constructing multi-service health centers is highly paid attention because of multiple nature of most diseases. Concentrating patients' medical services in one center prevents them from traveling to different parts of cities, especially in mega cities. In this research we have developed a mathematical model for the location of multi-service health centers assuming probabilistic demand and service time. Medical services are divided in three groups: normal, emergency and preventive. Since patients may be referred to another service after recieving a service by doctors' order, health system...
Robust Supply Chain Network Desing
, M.Sc. Thesis Sharif University of Technology ; Koorosh, Eshghi (Supervisor)
Abstract
Recently, the multi-level and multi-facility industrial problem in supply chain management (SCM) has been widely investigated. Supply chain network design (SCND) is one of the most important strategic decisions in supply chain management. The problem is an important management problem in SCM and aggregates the strategic and tactical and operational level of supply chain planning. The supply networks comprise a number of manufacturing sites, a number of warehouses and distribution centers of unknown locations to be selected from a set of potential locations, and finally a number of customer zones at fixed locations. The system is modeled mathematically as a mixed-integer linear programming...
Investigating the Robustness of Scale Free Supply Networks by Using the Concept of Assortative and Disassortative Networks
, M.Sc. Thesis Sharif University of Technology ; Koorosh, Eshghi (Supervisor)
Abstract
Supply networks are often faced with disruptions that hampered the flow of goods, and have brought irreparable consequences. In this thesis, we evaluate the robustness of three echelon scale free supply chain networks consist of manufacturers, distributers and retailers from the perspective of complex network topologies and investigate the effect of assortativity and disassortativity level on the robustness of scale free supply networks. For this purpose, we use the degree preserving rewiring approach in order to increase and decrease assortativity and disassortativity of scale free networks. Then we use metrics in order to investigate the robustness and flexibility of supply networks and...
A Meta-Heuristic Approach for a Special Class of Job Shop Scheduling Problem
, M.Sc. Thesis Sharif University of Technology ; Koorosh, Eshghi (Supervisor)
Abstract
The job shop scheduling problem is an important and applicable optimization problem and has been attracted by many researchers in recent decades. A huge amount of applications of job shop scheduling problem in industries and services has been found yet. During the last decade, the sequence dependent setup time constraint has been considered in many researches, but with respect to the knowledge of authors, very few of these researches have considered the inseparable setup. Furthermore, few of them have considered the release date assumption. In this thesis, the classical job shop scheduling problem and the inseparable sequence dependent setup time and release date constrained problem have...
Modeling and Solving On-line Ride Sharing Problem with Modified Dial-a-Ride Model
, M.Sc. Thesis Sharif University of Technology ; Eshghi, Koorosh (Supervisor)
Abstract
Today, considering the challenges that have been raised around fossil fuels and energy consumption in recent years, efforts have been made to reduce as much as possible the number of vehicles that are personal or single-passenger on the streets. For this purpose, a concept called travel sharing has been proposed in online platforms and businesses, where travelers can travel part or all of their journey with other travelers, but pay less money. The purpose of this research is to solve the problem of allocation and accessibility of passengers and cars in travel-sharing systems. To move in this direction, we have used mathematical programming tools and designed online algorithms to solve this...
Behavior of Angle Shear Connectors
, M.Sc. Thesis Sharif University of Technology ; Maleki, Shervin (Supervisor)
Abstract
The application of composite systems has rapidly advanced in bridge and building construction. Shear connectors are the most basic parts of the composite systems.The connectors transfer the shear forces between the slab and the beam. They also prevent separation of the slab from the beam.
Therefore researchers have done widespread studies on the behavior of shear connectors and their load carrying capacity. Steel angles are one of the shear connectors that can be used incompositesystems. Only limited number ofstudies has investigated thebehavior of thistype of connector.
The purpose of this thesis is to investigate the behavior of angle shear connectors embedded in solid concrete...
Therefore researchers have done widespread studies on the behavior of shear connectors and their load carrying capacity. Steel angles are one of the shear connectors that can be used incompositesystems. Only limited number ofstudies has investigated thebehavior of thistype of connector.
The purpose of this thesis is to investigate the behavior of angle shear connectors embedded in solid concrete...
Review of Contemporary Islamology Streams as Rational Traditions, Considering Macintyre View Points
, M.Sc. Thesis Sharif University of Technology ; Golshani, Mahdi (Supervisor)
Abstract
Shia theology has gone through different transformations throughout history. In the contemprorary age diverse studies have been carried out in order to discribe it’s preceding changes and future transformations. This tesis tends to show at first that “MacIntyre’s method of historical-philosophical study” is an overally justified model for such studeis, in comparison with the two other models of “Kuhn’s model of scientific revolutions” & “Lakatos’s research programs.” Afterwards, this model has been used for the study of shia theology and a brief narration of the rationality traditions of shia theology through the Iranian tradition has been given. The focus of this section has been on the...
Digital Marketing Management in Businesses and Startups Using Dynamic Systems Modeling
, M.Sc. Thesis Sharif University of Technology ; Shadrokh, Shahram (Supervisor)
Abstract
As today's world becomes more digital in every way, digital marketing has become a thriving industry, and digital marketing has become an important part of the world of digital business. Given the importance of this issue and the prominent role of startups in the today’s business world, in this project we discuss about digital marketing in start-ups business with a view to health sector using dynamic systems modeling. First, the effective variables are determined, then the relationships between them are determined and the model is designed. Finally, after analyzing the model factors and determining the extent and type of its impact on the main factors and variables, smooth the way to create...
Formation Control of Networked Autonomous Aerial Robots Subject to False Data Injection
, Article ICRoM 2024 - 12th RSI International Conference on Robotics and Mechatronics ; 2024 , Pages 28-33 ; 979-833152973-4 (ISBN) ; Attar, M ; Sharif University of Technology
2024
Abstract
This study investigates the leader-following formation control problem for the networked second-order autonomous arial robot systems under directed topology. It is assumed that the leader's velocity is time varying and formation control will be achieved under the assumption. The formation controller will be designed to form the desired formation of all followers and reached the consensus of velocity. Moreover, it has assumed that agents may expose to a false data injection as a cyber-attack and this affair can affect the transferred sensor information that agents share with each other and break the formation. Finally, a Kalman filter and a chi-square anomaly detector is proposed to detect...
Decision Analysis and Revenue Management In Health-Care
,
M.Sc. Thesis
Sharif University of Technology
;
Koorosh, Eshghi
(Supervisor)
Abstract
Nowadays, Resource Capacity Management (RCM) is one of the main challenges for industries which have a limited capacity to meet the demands. Revenue Management (RM) is a technique that controls the supply, improves the quality of Capacity Management and maximizes the revenue. Supplying the products and services to different groups of customers is a decision making problem.While the classic RM techniques take into account only the expected revenue, preferences of decision makers strongly affect the results. In this study, utility theory has been proposed because the healthcare industries are usually nonprofitable and they are not highly focused on the revenue gained by their products and...
Train Timetabling Optimization in Metro Networks
, M.Sc. Thesis Sharif University of Technology ; Koorosh, Eshghi (Supervisor)
Abstract
Train scheduling is a significant issue in the railway industry in recent years because it has an important role in railway infrastructure. In this paper, the timetabling problem of a multiple tracked railway network is discussed. More specifically, a general model with specific attention to “Tehran Metro” is presented here in which a set of operational and safety requirements are also considered. The model handles the trains overtaking in a station and innovatively considers the capacity of stations. An objective function is to minimize the total travel time. The problem is NP-hard so the real size problem cannot be solved in acceptable amount of time. In order to reduce the processing time...
Integration of Pricing and Ordering in a Supply Chain
, M.Sc. Thesis Sharif University of Technology ; Eshghi, Koorosh (Supervisor)
Abstract
Last decade witnessed a virtual explosion of information about customers and their priorities. This information gives some potentials to companies that increase their revenues, especially when new technologies make the possibility of changing prices with low costs. Simultaneously, companies had large development in dynamic management of supply chain in both internal operations of companies and their communications. Although pricing decisions have some effects on operations, but integration of operations and marketing are very common subjects in science and business. In this thesis, we consider the integration of dynamic pricing and ordering in a supply chain. Then, we present a dynamic...
Modeling Multi-path Covering Routing Problem
, M.Sc. Thesis Sharif University of Technology ; Koorosh, Eshghi (Supervisor)
Abstract
The location problem is one of the main topics at the strategic level. This problem is investigated along with many areas such as network design and path covering problems. Routing between source and destination nodes is done in such a way that maximizes traffic coverage and reduces costs as much as possible. Routing problems are considered in goods distribution areas and urban transit systems. Goods distribution from set of cross-docks can help to reduce costs and improve resource efficiency. So, this topic is considered in this research and a suitable model is proposed. Defining and developing of the road and rail transportation networks are main topics in urban traffic management which...
Critical graphs in index coding
, Article IEEE International Symposium on Information Theory - Proceedings ; 2014 , p. 281-285 ; Shahrasbi, A ; Gohari, A ; Sharif University of Technology
2014
Abstract
In this paper we define critical graphs as minimal graphs that support a given set of rates for the index coding problem, and study them for both the one-shot and asymptotic setups. For the case of equal rates, we find the critical graph with minimum number of edges for both one-shot and asymptotic cases. For the general case of possibly distinct rates, we show that for one-shot and asymptotic linear index coding, as well as asymptotic non-linear index coding, each critical graph is a union of disjoint strongly connected subgraphs (USCS). On the other hand, we identify a non-USCS critical graph for a one-shot non-linear index coding problem. In addition, we show that the capacity region of...
Optimum power of a nonlinear piezomagnetoelastic energy harvester with using multidisciplinary optimization algorithms
, Article Journal of Intelligent Material Systems and Structures ; 2020 ; Jamshiddoust, A ; Farrokhabadi, A ; Sharif University of Technology
SAGE Publications Ltd
2020
Abstract
Energy-harvesting devices have been widely used to generate electrical power. Through the use of energy harvesting techniques, ambient vibration energy can be captured and converted into usable electricity in order to create self-powering systems. In the present study, to further improve the efficiency of energy-harvesting devices, a nonlinear piezomagnetoelastic energy harvester is proposed in two different configurations that is parallel and series. In order to optimize the generated electrical power, the physical parameters of the harvester are chosen as the design variables. Classical and Metaheuristic algorithms, namely, random search, genetic algorithm, and simulated annealing are...