Loading...
Search for: integer-linear-programming
0.007 seconds
Total 190 records

    Optimal production-distribution planning in electromotor manufacturing industries: a case study

    , Article International Journal of Advanced Operations Management ; Volume 12, Issue 1 , 28 May , 2020 , Pages 1-27 ; Print ISSN: 1758-938X; Online ISSN: 1758-9398 Heydarabadi, H ; Doniavi, A ; Babazadeh, R ; Shahmohammadi Azar, H ; Sharif University of Technology
    Inderscience Publishers  2020
    Abstract
    Optimal production-distribution planning prevents capital accumulation, reduces costs, unemployment of machinery, and provides a good plan to satisfying customer needs. In this paper, a mixed-integer linear programming (MILP) model is developed to determine optimal production-distribution planning in electromotor manufacturing industries. The proposed model is a multi-product and multi-period one in which optimal amounts of production, inventory and distribution are determined in different periods. Also, the possibility of capacity expansion of facilities in different periods are modelled to optimally determine the capacity increase if necessary. To validate the proposed model, it is applied... 

    A milp model for incorporating reliability indices in distribution system expansion planning

    , Article IEEE Transactions on Power Systems ; Volume 34, Issue 3 , 2019 , Pages 2453-2456 ; 08858950 (ISSN) Jooshaki, M ; Abbaspour, A ; Fotuhi-Firuzabad, M ; Farzin, H ; Moeini-Aghtaie, M ; Lehtonen, M ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2019
    Abstract
    Reliability cost is considered as an inevitable criterion in expansion planning studies of distribution systems. However, nonlinear expressions of reliability indices aggravate complexity of planning studies. To address this issue, this letter proposes a novel method to linearize mathematical model of the reliability-based distribution expansion planning problem. Using this variant of reliability indices, reliability costs can easily be involved in mixed-integer linear programming model of distribution expansion planning. Validity of the derived expressions is tested by simulation results. © 1969-2012 IEEE  

    Optimization-based distribution system reliability evaluation: An enhanced MILP model

    , Article 4th International Conference on Smart Energy Systems and Technologies, SEST 2021, 6 September 2021 through 8 September 2021 ; 2021 ; 9781728176604 (ISBN) Jooshaki, M ; Lehtonen, M ; Fotuhi Firuzabad, M ; Munoz Delgado, G ; Contreras, J ; Arroyo, J. M ; University of Vaasa ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2021
    Abstract
    Standard mathematical-programming-based models have attracted considerable attention for optimizing distribution system planning and operation due to their salient advantages. More specifically, mixed-integer linear programming (MILP) has proven very effective in modeling such problems. The availability of optimization software for efficiently solving MILP problems with guaranteed convergence to optimality while providing a measure of the distance to the optimal solution has made MILP models more popular. Although a plethora of efficient MILP formulations have been proposed for planning and operating studies of distribution grids, incorporating reliability into such models is still... 

    ISO's optimal strategies for scheduling the hourly demand response in day-ahead markets

    , Article IEEE Transactions on Power Systems ; Vol. 29, issue. 6 , 2014 , p. 2636-2645 ; ISSN: 8858950 Parvania, M ; Fotuhi-Firuzabad, M ; Shahidehpour, M ; Sharif University of Technology
    Abstract
    This paper presents a hierarchical demand response (DR) bidding framework in the day-ahead energy markets which integrates customer DR preferences and characteristics in the ISO's market clearing process. In the proposed framework, load aggregators submit aggregated DR offers to the ISO which would centrally optimize final decisions on aggregators' DR contributions in wholesale markets. The hourly load reduction strategies include load shifting and curtailment and the use of onsite generation and energy storage systems. The ISO applies mixed-integer linear programming (MILP) to the solution of the proposed DR model in the day-ahead market clearing problem. The proposed model is implemented... 

    A market mechanism to quantify emergency energy transactions value in a multi-microgrid system

    , Article IEEE Transactions on Sustainable Energy ; 2017 ; 19493029 (ISSN) Farzin, H ; Ghorani, R ; Fotuhi Firuzabad, M ; Moeini Aghtaie, M ; Sharif University of Technology
    Abstract
    In this paper, a new market mechanism is proposed to quantify the value of emergency energy transactions in renewable-based multi-microgrid (MMG) systems. To reach this goal, main requirements and features of such emergency market are identified. Subsequently, a hybrid market framework is proposed which integrates pool emergency transactions and bilateral contracts in order to reduce the system risk in face of different contingency events. For settling different transactions in this market, the main procedure which should be followed by distribution system operator (DSO) to properly address bidding of microgrids (MGs) as well as system technical constraints are introduced. In addition, a... 

    Nondominated nash points: application of biobjective mixed integer programming

    , Article 4OR ; 2017 , Pages 1-21 ; 16194500 (ISSN) Charkhgard, H ; Savelsbergh, M ; Talebian, M ; Sharif University of Technology
    Abstract
    We study the connection between biobjective mixed integer linear programming and normal form games with two players. We first investigate computing Nash equilibria of normal form games with two players using single-objective mixed integer linear programming. Then, we define the concept of efficient (Pareto optimal) Nash equilibria. This concept is precisely equivalent to the concept of efficient solutions in multi-objective optimization, where the solutions are Nash equilibria. We prove that the set of all points in the payoff (or objective) space of a normal form game with two players corresponding to the utilities of players in an efficient Nash equilibrium, the so-called nondominated Nash... 

    A transportation network model with intelligent probabilistic travel times and two hybrid algorithms

    , Article Transportation Letters ; Volume 9, Issue 2 , 2017 , Pages 90-122 ; 19427867 (ISSN) Shiripour, S ; Mahdavi Amiri, N ; Mahdavi, I ; Sharif University of Technology
    Taylor and Francis Ltd  2017
    Abstract
    A main component of a transportation network is travel time or distance. Due to stochastic events such as accidents and failures in roads, a deterministic estimation of the travel time between two cities or regions is impossible. Also, on special occasions like holidays, with increase in the traveling population in the transportation network, probabilities of occurrence of these events increase. The increase in traveling population has a direct effect on the estimation of travel times and subsequently on the decision-making process. Therefore, provision of an appropriate model for the intelligent probabilistic travel times to distribute the population in a transportation network is a... 

    Nondominated nash points: application of biobjective mixed integer programming

    , Article 4OR ; Volume 16, Issue 2 , 2018 , Pages 151-171 ; 16194500 (ISSN) Charkhgard, H ; Savelsbergh, M ; Talebian, M ; Sharif University of Technology
    Springer Verlag  2018
    Abstract
    We study the connection between biobjective mixed integer linear programming and normal form games with two players. We first investigate computing Nash equilibria of normal form games with two players using single-objective mixed integer linear programming. Then, we define the concept of efficient (Pareto optimal) Nash equilibria. This concept is precisely equivalent to the concept of efficient solutions in multi-objective optimization, where the solutions are Nash equilibria. We prove that the set of all points in the payoff (or objective) space of a normal form game with two players corresponding to the utilities of players in an efficient Nash equilibrium, the so-called nondominated Nash... 

    Optimizing constrained single period problem under random fuzzy demand

    , Article International Conference on Numerical Analysis and Applied Mathematics, ICNAAM 2008, Psalidi, Kos, 16 September 2008 through 20 September 2008 ; Volume 1048 , 2008 , Pages 43-46 ; 0094243X (ISSN) ; 9780735405769 (ISBN) Taleizadeh, A. A ; Shavandi, H ; Riazi, A ; Sharif University of Technology
    2008
    Abstract
    In this paper, we consider the multi-product multi-constraint newsboy problem with random fuzzy demands and total discount. The demand of the products is often stochastic in the real word but the estimation of the parameters of distribution function may be done by fuzzy manner. So an appropriate option to modeling the demand of products is using the random fuzzy variable. The objective function of proposed model is to maximize the expected profit of newsboy. We consider the constraints such as warehouse space and restriction on quantity order for products, and restriction on budget. We also consider the batch size for products order. Finally we introduce a random fuzzy multi-product... 

    A practical exact algorithm for the shortest loop design problem in a block layout

    , Article International Journal of Production Research ; Volume 43, Issue 9 , 2005 , Pages 1879-1887 ; 00207543 (ISSN) Zanjirani Farahani, R ; Laporte, G ; Sharifyazdi, M ; Sharif University of Technology
    2005
    Abstract
    The problem of determining a shortest loop incident to each cell of a block layout is considered. A compact formulation is developed for this problem and a relatively simple algorithm is presented. It is shown that instances containing up to 60 cells can be solved optimally by using a commercial integer linear programming solver embedded within an iterative scheme. © 2005 Taylor & Francis Group Ltd  

    A new linear programming approach and genetic algorithm for solving airline boarding problem

    , Article Applied Mathematical Modelling ; Volume 36, Issue 9 , 2012 , Pages 4060-4072 ; 0307904X (ISSN) Soolaki, M ; Mahdavi, I ; Mahdavi Amiri, N ; Hassanzadeh, R ; Aghajani, A ; Sharif University of Technology
    Abstract
    The airline industry is under intense competition to simultaneously increase efficiency and satisfaction for passengers and profitability and internal system benefit for itself. The boarding process is one way to achieve these objectives as it tends itself to adaptive changes. In order to increase the flying time of a plane, commercial airlines try to minimize the boarding time, which is one of the most lengthy parts of a plane's turn time. To reduce boarding time, it is thus necessary to minimize the number of interferences between passengers by controlling the order in which they get onto the plane through a boarding policy. Here, we determine the passenger boarding problem and examine the... 

    Prioritizing demand response programs from reliability aspect

    , Article 2012 11th International Conference on Environment and Electrical Engineering, EEEIC 2012 - Conference Proceedings ; 2012 , Pages 229-234 ; 9781457718281 (ISBN) Nikzad, M ; Bashirvand, M ; Mozafari, B ; Ranjbar, A. M ; Sharif University of Technology
    IEEE  2012
    Abstract
    In this paper, the impact of demand response programs (DRPs) on reliability improvement of the restructured power systems is quantified. In this regard, the demand response (DR) model which treats consistently the main characteristics of the demand curve is developed for modeling. In proposed model, some penalties for customers in case of no responding to load reduction and incentives for customers who respond to reducing their loads are considered. In order to make analytical evaluation of the reliability, a mixed integer DCOPF is proposed by which load curtailments and generation re-dispatches for each contingency state are determined. Both transmission and generation failures are... 

    Optimizing a bi-objective multi-product multi-period three echelon supply chain network with warehouse reliability

    , Article Expert Systems with Applications ; Volume 42, Issue 5 , April , 2014 , Pages 2615-2623 ; 09574174 (ISSN) Pasandideh, S. H. R ; Niaki, S. T. A ; Asadi, K ; Sharif University of Technology
    Elsevier Ltd  2014
    Abstract
    Bi-objective optimization of a multi-product multi-period three-echelon supply chain network consisting of manufacturing plants, distribution centers (DCs) each with uncertain services, and customer nodes is aimed in this paper. The two objectives are minimization of the total cost while maximizing the average number of products dispatched to customers. The decision variables are: (1) the number and the locations of reliable DCs in the network, (2) the optimum number of items produced by plants, (3) the optimum quantity of transported products, (4) the optimum inventory of products at DCs and plants, and (5) the optimum shortage quantity of the customer nodes. The problem is first formulated... 

    MILP model of electricity distribution system expansion planning considering incentive reliability regulations

    , Article IEEE Transactions on Power Systems ; Volume 34, Issue 6 , 2019 , Pages 4300-4316 ; 08858950 (ISSN) Jooshaki, M ; Abbaspour, A ; Fotuhi Firuzabad, M ; Moeini Aghtaie, M ; Lehtonen, M ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2019
    Abstract
    This paper aims at proposing a mixed-integer linear formulation to incorporate reliability-oriented costs into the expansion planning model of electricity distribution networks. In this respect, revenue lost associated with the undelivered energy caused by network interruptions as well as costs incurred by the widely used reward-penalty regulations is considered as the major reliability-related costs from distribution companies point of view. A set of mixed-integer linear equations is proposed to calculate the most common distribution system reliability indices, i.e., expected energy not served, system average interruption frequency index, and system average interruption duration index. It... 

    Flexibility scheduling for large customers

    , Article IEEE Transactions on Smart Grid ; Volume 10, Issue 1 , 2019 , Pages 371-379 ; 19493053 (ISSN) Angizeh, F ; Parvania, M ; Fotuhi Firuzabad, M ; Rajabi Ghahnavieh, A ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2019
    Abstract
    Large customers are considered as major flexible electricity demands which can reduce their electricity costs by choosing appropriate strategies to participate in demand response programs. However, practical methods to aid the large customers for handling the complex decision making process for participating in the programs have remained scarce. This paper proposes a novel decision-making tool for enabling large customers to determine how they adjust their electricity usage from normal consumption patterns in expectation of gaining profit in response to changes in prices and incentive payments offered by the system operators. The proposed model, formulated as a mixed-integer linear... 

    The utilization of patients’ information to improve the performance of radiotherapy centers: A data-driven approach

    , Article Computers and Industrial Engineering ; Volume 172 , 2022 ; 03608352 (ISSN) Moradi, S ; Najafi, M ; Mesgari, S ; Zolfagharinia, H ; Sharif University of Technology
    Elsevier Ltd  2022
    Abstract
    The high demand for radiotherapy services, combined with the limited capacity of available resources, patient unpunctuality, and series of appointments, makes Patient Appointment Scheduling (PAS) in radiotherapy centers very challenging. Although most centers use a First-Come-First-Serve (FCFS) policy for appointment scheduling, this approach does not consider patients’ behaviors, and consequently, it performs poorly. This type of inappropriate scheduling usually leads to inefficiency at the center and/or patient dissatisfaction. This study provides a data-driven approach to patient appointment scheduling to deal with the challenges mentioned above, and it considers patients’ histories of... 

    The Inventory – Routing Problem Considering Discount

    , M.Sc. Thesis Sharif University of Technology Asvadi, Saman (Author) ; Shavandi, Hassan (Supervisor)
    Abstract
    In this research, the inventory – routing problem considering discount is studied. The problem consists of a supplier and several retailers who form a network of demand and supply points. In this research, offering discount to retailers is considered as an appropriate policy for reducing total costs of the supply chain. The supplier can augment the utility of her trucks by offering discounts and incentives to the retailers and delivering them amounts of product beyond their economic ordering quantity. This way, the supplier can have full truck-loads instead of lower than full truck-loads while delivering the demands of the retailers. This, can result in a decrease in transportation costs and... 

    Multi Objective Optimization of Distributed Energy Systems Considering Renewables and Fossil Fuel Resources

    , M.Sc. Thesis Sharif University of Technology Maroufmashat, Azadeh (Author) ; Sattari Khavas, Sourena (Supervisor) ; Roshandel, Ramin (Supervisor)
    Abstract
    Urban energy systems are responsible for the majority of the energy consumption around the world and they play an important role in energy issues such as economic security and climate change. Furthermore, there are growing concerns about the depletion of fossil fuel resources and the negative effect they have had on the ecosystem. To this end, a holistic and integrated approach is necessary for the optimal design and operation of urban energy systems that makes expressive betterment in energy efficiency and environmental impact. The aim of this research is to develop an optimum methodology for communities in the context of energy hub. The energy hub is a novel concept to systematically... 

    Optimal equilibrium selection of price-maker agents in performance-based regulation market

    , Article Journal of Modern Power Systems and Clean Energy ; Volume 10, Issue 1 , 2022 , Pages 204-212 ; 21965625 (ISSN) Rayati, M ; Sheikhi, A ; Ranjbar, A. M ; Sun, W ; Sharif University of Technology
    State Grid Electric Power Research Institute Nanjing Branch  2022
    Abstract
    This paper analyzes the oligopolistic equilibria of multiple price-maker agents in performance-based regulation (PBR) markets. In these markets, there are price-maker agents representing some frequency regulation (FR) providers and a number of independent price-taker FR providers. A model of equilibrium problem with equilibrium constraints (EPECs) is employed in this paper to study the equilibria of a PBR market in the presence of price-maker agents and price-taker FR providers. Due to the incorporation of the FR providers' dynamics, the proposed model is reformulated as a mixed-integer linear programming (MILP) problem over innovative mathematical techniques. An optimal equilibrium point is... 

    Optimum Unit Size in Generation Expansion Planning Based on Reliability Criteria

    , M.Sc. Thesis Sharif University of Technology Tohidi, Yaser (Author) ; Fotuhi Firouzabad, Mahmud (Supervisor)
    Abstract
    Increasing demand in power systems necessitates the Generation Expansion Planning (GEP) which is to determine the type, size, and location of new generating units in a planning horizon. The final solution of GEP is based on the minimum cost and/or optimum reliability taking into account various constraints such as capacity of units and lines, operating constraints, and budget restrictions. This paper presents a model based on scenarios for generation expansion planning and units retirement decision. The proposed model could be used by vertically integrated utilities as well as the ISOs in electricity markets to obtain generation expansion schemes. In this approach, uncertainty of units are...