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benders-decomposition
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Strategies for protecting supply chain networks against facility and transportation disruptions: An improved Benders decomposition approach
, Article Annals of Operations Research ; Volume 210, Issue 1 , 2013 , Pages 125-163 ; 02545330 (ISSN) ; Saharidis, G. K. D ; Davoudpour, H ; Malekly, H ; Yektamaram, S. A ; Sharif University of Technology
2013
Abstract
Disruptions rarely occur in supply chains, but their negative financial and technical impacts make the recovery process very slow. In this paper, we propose a capacitated supply chain network design (SCND) model under random disruptions both in facility and transportation, which seeks to determine the optimal location and types of distribution centers (DC) and also the best plan to assign customers to each opened DC. Unlike other studies in the extent literature, we use new concepts of reliability to model the strategic behavior of DCs and customers at the network: (1) Failure of DCs might be partial, i.e. a disrupted DC might still be able to serve with a portion of its initial capacity (2)...
A bi-objective robust optimization model for a blood collection and testing problem: an accelerated stochastic benders decomposition
, Article Annals of Operations Research ; 2018 ; 02545330 (ISSN) ; Pasandideh, S. H. R ; Aghaie, A ; Akhavan Niaki, S. T ; Sharif University of Technology
Abstract
Blood transfusion services are vital components of healthcare systems all over the world. In this paper, a generalized network optimization model is developed for a complex blood supply chain in accordance with Iranian blood transfusion organization (IBTO) structure. This structure consist of four types facilities. Blood collection centers, blood collection and processing centers, mobile teams and blood transfusion center have various duties in IBTO structure. The major contribution is to develop a novel hybrid approach based on stochastic programming, ε-constraint and robust optimization (HSERO) to simultaneously model two types of uncertainties by including stochastic scenarios for total...
The Planning and Scheduling of Operating Rooms under the Open Scheduling Strategy and Uncertainty
, M.Sc. Thesis Sharif University of Technology ; Rafiee, Majid (Supervisor)
Abstract
Operating rooms has always been considered as one of the most expensive, yet most profitable part of a hospital. Since many units in the hospitals are related to the operating room, improving efficiency in the operating room will result in increased efficiency in other units, so offering proper solutions in this area is very important. Suitable Planning and scheduling has a great impact on increasing the level of service and efficiency of the hospital. in this thesis, a mixed integer programming model for scheduling weekly elective patients in the surgical theater with the objective of maximizing the number of elective patients for the surgery and also the workload of the operating room...
A Novel Heuristic Mathematical Model for Cloud Manufacturing Service Composition Problem Focusing on Benders Algorithm
, M.Sc. Thesis Sharif University of Technology ; Fatahi Valilai, Omid (Supervisor)
Abstract
Today, Information Technology is a critical aspect for the development of the modern manufacturing industry. Network technology can connect customers, partners, and the general public to work together and provide resources across the supply chain to improve product performance. To meet the goal of higher performance with lower operational costs and shorter delivery times for new products, many network-driven or service-oriented models have been proposed. These models focus more on communicating with dispersed partners rather than Integrated management and generalization of dynamic resource partnerships. But, cloud manufacturing has been recognized in the literature for generating computing...
Optimizing Transmisson from Distant Wind Farms
, M.Sc. Thesis Sharif University of Technology ; Hosseini, Hamid (Supervisor)
Abstract
Wind power is site dependent and is by nature partially dispatchable. Furthermore, good wind sites are far from grid. Due to these problems, and along with the existing limitations in the transmission networks, a comprehensive analysis over an extended time is needed to properly explore all potential wind sites for wind capacity allocation. This problem is computationally expensive and decomposition methods are required to break down this problem. Here Benders decomposition approach is used, which is a popular technique for solving large-scale problems, to decompose the original problem into a master and a subproblem. The master problem is a linear problem, which allocates wind capacity to...
Planning of Energy Storage Systems in the Restructured Environment by Considering Uncertainties
, M.Sc. Thesis Sharif University of Technology ; Ehsan, Mahdi (Supervisor)
Abstract
Energy storage is a pivotal technology to dealing with increasing demand for reliability and challenges of renewable energy integration. This thesis provides a benders decomposition framework for expansion studies of energy storage systems (ESSs) in high wind penetrated power system and uncertainties of wind farms expansion and wind speed. This work proposes probabilistic and robust approaches to determine the optimal location and size of storage devices to reduse wind curtailment. The proposed methodologies are implemented on the modified IEEE 73-bus test system and their anticipated applicability are compared to each other and well verified
Wind farm optimal connection to transmission systems considering network reinforcement using cost-reliability analysis
, Article IET Renewable Power Generation ; Volume 7, Issue 6 , 2013 , Pages 603-613 ; 17521416 (ISSN) ; Hosseini, S. H ; Sharif University of Technology
2013
Abstract
In this study, a novel network reinforcement model incorporating optimal wind farms (WFs) integration to power systems is proposed. Based on the reinforcement model, new transmission lines are added to the network for eliminating the transmission network congestion. In addition, a methodology for determining the WFs optimal capacities, the economical WF lines transfer rates and the appropriate reinforcement plan, whereas maximising the total benefit using cost-reliability analysis is presented. In this way, the objective of the proposed optimisation problem has been divided into a master problem and two subproblems. Benders decomposition is employed to connect the master and subproblems of...
Minimum cost multiple multicast network coding with quantized rates
, Article Computer Networks ; Volume 57, Issue 5 , 2013 , Pages 1113-1123 ; 13891286 (ISSN) ; Salehi Fathabadi, H ; Khalaj, B. H ; Khodayifar, S ; Sharif University of Technology
2013
Abstract
In this paper, we consider multiple multicast sessions with intra-session network coding where rates over all links are integer multiples of a basic rate. Although having quantized rates over communication links is quite common, conventional minimum cost network coding problem cannot generally result in quantized solutions. In this research, the problem of finding minimum cost transmission for multiple multicast sessions with network coding is addressed. It is assumed that the rate of coded packet injection at every link of each session takes quantized values. First, this problem is formulated as a mixed integer linear programming problem, and then it is proved that this problem is strongly...
MILP model for integrated expansion planning of multi-carrier active energy systems
, Article IET Generation, Transmission and Distribution ; Volume 13, Issue 7 , 2019 , Pages 1177-1189 ; 17518687 (ISSN) ; Aghaei, J ; Gharehpetian, G. B ; Safdarian, A ; Sharif University of Technology
Institution of Engineering and Technology
2019
Abstract
In growing economic energy systems, the interdependency of various energy infrastructures has led to a change in countries' policies in their expansion planning of energy networks. In this study, a mixed-integer non-linear programming (MINLP) model is proposed for expansion planning of the multi-carrier systems including electricity and gas distribution networks. The optimal planning determines the best location, time, and alternative for network assets in order to minimise investment costs and reduce losses. Also, as another distinctive feature of this study, given the integration of electricity and gas distribution networks and the complexity of the problem, a new MILP model using...
Dynamic interdiction networks with applications in illicit supply chains
, Article Omega (United Kingdom) ; 2019 ; 03050483 (ISSN) ; Zolfagharinia, H ; Najafi, M ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
We study the interdiction of illegal product distribution in a network with multiple sources (origins) and sinks (destinations). This work contributes to the literature of dynamic maximum flow interdiction problems by addressing multiple commodities in a network of relationships. The related distribution network consists of (1) criminals, who are hierarchically connected, and seeking to maximize the total profit flow from origins to destinations, and (2) enforcement officers aiming to minimize criminals’ long-term success by monitoring and arresting them, using the limited resources at their disposal. Considering several real-world operational details, we first propose a mixed-integer...
Dynamic interdiction networks with applications in illicit supply chains
, Article Omega (United Kingdom) ; 2019 ; 03050483 (ISSN) ; Zolfagharinia, H ; Najafi, M ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
We study the interdiction of illegal product distribution in a network with multiple sources (origins) and sinks (destinations). This work contributes to the literature of dynamic maximum flow interdiction problems by addressing multiple commodities in a network of relationships. The related distribution network consists of (1) criminals, who are hierarchically connected, and seeking to maximize the total profit flow from origins to destinations, and (2) enforcement officers aiming to minimize criminals’ long-term success by monitoring and arresting them, using the limited resources at their disposal. Considering several real-world operational details, we first propose a mixed-integer...
Dynamic interdiction networks with applications in illicit supply chains
, Article Omega (United Kingdom) ; Volume 96 , October , 2020 ; Zolfagharinia, H ; Najafi, M ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
We study the interdiction of illegal product distribution in a network with multiple sources (origins) and sinks (destinations). This work contributes to the literature of dynamic maximum flow interdiction problems by addressing multiple commodities in a network of relationships. The related distribution network consists of (1) criminals, who are hierarchically connected, and seeking to maximize the total profit flow from origins to destinations, and (2) enforcement officers aiming to minimize criminals’ long-term success by monitoring and arresting them, using the limited resources at their disposal. Considering several real-world operational details, we first propose a mixed-integer...
Phase identification of singlephase customers and PV panels via smart Meter data
, Article IEEE Transactions on Smart Grid ; Volume 12, Issue 5 , 2021 , Pages 4543-4552 ; 19493053 (ISSN) ; Safdarian, A ; Aminifar, F ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2021
Abstract
With proliferation of single-phase rooftop photovoltaic (PV) panels, phase balancing in low voltage (LV) distribution feeders becomes the point of concern. In this way, identification of the hosting phase of connected single-phase customers and PV panels is a prerequisite. This paper proposes an optimization model for the phase identification problem. The objective is to minimize the summation of the absolute error between estimated and measured variables. Smart meters (SMs) data including active and reactive power absorptions/injections, nodal voltage magnitudes, and network configuration data form the input of the model. Potential errors in the input data are captured in the model while...
Voltage security constrained multi-period optimal reactive power flow using benders and optimality condition decompositions
, Article IEEE Transactions on Power Systems ; Volume 28, Issue 2 , 2013 , Pages 696-708 ; 08858950 (ISSN) ; Parniani, M ; Sharif University of Technology
2013
Abstract
This paper proposes a new coordinated voltage control scheme to ensure voltage security of power systems. The scheme schedules reactive power injection from VAR sources, including synchronous generators and condensers, capacitor banks, switchable reactors and FACTS devices, to ensure desired loading margin of power systems for a given horizon of time. The problem is treated as voltage security constrained multi-period optimal reactive power flow (VSC-MPORPF). To incorporate scheduling of both continuous and discrete VAR sources, the VSC-MPORPF is formulated as a mixed-integer nonlinear programming problem, and is solved using generalized Benders decomposition (GBD). Multi-period formulation...
Coordinated Voltage Control of Power Systems in Normal and Emergency Operation States
, Ph.D. Dissertation Sharif University of Technology ; Parniani, Mostafa (Supervisor)
Abstract
One of the main objectives in operating a power system is to maintain the system voltage properly to avoid equipment damage and transfer power efficiently. Automatic control of transmission network voltage provides significant improvements in security, quality and efficiency of power system operation. This thesis investigates coordinated voltage control of power systems in normal, alert and emergency states. The aim is to propose a comprehensive framework for real-time operation of practical power systems, ensuring secure operation of the system in the normal state and after occurrence of sever contingencies.
At the first, a new coordinated voltage control scheme is proposed to ensure...
At the first, a new coordinated voltage control scheme is proposed to ensure...
Optimal Bundle Pricing for Limited Stocks and Stochastic Demand
, M.Sc. Thesis Sharif University of Technology ; Modarres Yazdi, Mohammad (Supervisor)
Abstract
This study investigates the bundle pricing strategy in which a seller offers both individual products and a bundle comprising one unit of each individual product. Moreover in order to motivate costumers, usually a discount is offered for the bundle option. This strategy is an important price discrimination tool for companies that serve customers with heterogeneous preferences and implementing it can maximize seller’s expected profits. In this study two mathematical programming models for the mixed bundle pricing problem are developed. The first model investigates the inventory and ordering decisions in this problem. In order to solve this model, a solution approach based on the benders...
Transmission Expansion Planning Considering Optimal Wind Farms Integration
, Ph.D. Dissertation Sharif University of Technology ; Hosseini, Hamid (Supervisor)
Abstract
The significant growth of wind generation in power systems, in form of wind farms connected to transmission networks, is changing the present transmission reinforcement planning in the mid-term horizon and transmission expansion planning in the long-term horizon approaches. In this thesis, the optimal wind farms integration to the power system and uncertainty of wind farms output power are considered as two major items in the proposed models and the novel transmission reinforcement and expansion planning models considering optimal wind farms integration are presented. According to these models, the optimal capacity of wind farms and wind farms lines, and the new transmission lines of the...
Robust Scheduling of Flexible Units in Real-time Market Considering Demand Response Effects
, M.Sc. Thesis Sharif University of Technology ; Hosseini, Hamid (Supervisor)
Abstract
With the expansion of renewable energy resources in power systems, due to the uncertainty with the output power of these power plants, there is a price sparks and load curtailment for some hours. One of the most important reasons for this sparks is the limited ability of units to provide unexpected changes in net load; on the other hand, the retirement of units with flexible thermal capacity, this liability in providing net load changes is more visible than before, because of the limited in ramprate of power plants at a specified time interval. For this reason, some of the independent system operators (ISO) have introduced various strategies to increase the system's flexibility to provide...
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...
Transmission Expansion Planning Considering Network Topology Optimization
, M.Sc. Thesis Sharif University of Technology ; Fotuhi-Firuzabad, Mahmud (Supervisor)
Abstract
With increasing demand levels in recent years, transmission congestion is considered as one of the most important power system constraints. This limitation can result in higher operational costs and load curtailment. Furthermore, in power systems with high penetration of wind power, a significant amount of wind curtailment may occur due to congestion of transmission lines. Thus, in order to guarantee a reliable and economic operation of the power system, new transmission lines should be constructed with a rational plan. Very high investment costs are required for building new transmission lines to meet the growing demand. This fact as well as the other associated difficulties emphasize the...