Optimization of Service Composition Problem in Cloud Manufacturing

, M.Sc. Thesis Sharif University of Technology Kerdegari, Adeleh (Author) ; Eshghi, Koroush (Supervisor)

Abstract

Service composition is an important problem in the cloud manufacturing paradigm in which, after receiving a customer request, combination of cloud services are determined for accomplishment of customer needs. Actually, customer need is decomposed to some distinct tasks such that each one is done by a company or a group of them. In this way, virtual and cloud-based production line can be developed based on requirements of customers. The ultimate goal of service composition is optimum assignment of tasks to factories while some objective functions (e.g. minimization of cost and time) and constraints (e.g. minimum reliability and availability) are considered. In this study, integer programming...

Maximum Weighted Mixed-Graph Orientation with Transportation Cost

, M.Sc. Thesis Sharif University of Technology Azadnia, Alireza (Author) ; Eshghi, Koroush (Supervisor)

Abstract

The following research considers the problem of maximum graph orientation aiming to maximize the total weight of satisfied origin-destination pairs for which the capacity of each edge is limited taking into account the distance and cost. the origin of this problem can be traced to biology literature and protein-protein interaction networks. since the problem is a combinatorial optimization one, in addition to deploying exact methods using mathematical programming, heuristic methods are also investigated. addressing the problem, we propose a two-step procedure. in the first stage are detected the paths between origin-destination pairs and in the second one, the solution to the problem is...

Time Management in a Multi-Modal Routing Problem, Case Study: Rocoland Online Supermarket

, M.Sc. Thesis Sharif University of Technology Taheria, Sina (Author) ; Eshghi, Koroush (Supervisor)

Abstract

Communication growth in today’s world has affected every aspect of our lives. Transportation is an important part of our communication. Traveling, going from one place to another in a city or distribution of goods are examples of transportation. Transportation in which more than one vehicle is used from origin to destination is known as a multimodal transportation. This thesis is about a multimodal transportation problem for distribution of goods. Objective function is to minimize cost and there are constraints on the availability of the fleet. Also, it is possible in our model to use more cars with additional cost when the size of the fleet is not enough. The model is solved by optimization...

Planning and Scheduling Operating Theater Subject to Capacity after Surgery Unit

, M.Sc. Thesis Sharif University of Technology Sheikhi, Zohre (Author) ; Eshghi, Koroush (Supervisor)

Abstract

In today’s modern world, there is an ever-increasing need for developing new ways to provide service in a health system in order to gain the satisfaction of the patients with economically effective methods. One of the challenges faced by a hospital is the allocation of the surgeries to the available surgeans. In this study, a mathematical model is proposed to schedule the operation rooms while considering the daily availability of the doctors, the expense of the operations, overtime hours, and post-operation care. The mathematical programming model is optimized as a stochastic model by using the approach of BIM.
An essential aspect of a hospital system design is the uncertainity of the...

2-Echelon Location Routing Problem

, M.Sc. Thesis Sharif University of Technology Torabbeigi, Maryam (Author) ; Eshghi, Koroush (Supervisor)

Abstract

Supply chain management seeks to coordinate supply chain processes to achieve certain goals; one of which is minimizing the overall cost of the system. In this study integration of different supply chain management decisions i.e. location, routing and inventory management is considered in a single model. The products are distributed in a two-echelon distribution system. One type of product is shipped from a single factory to multiple retailers with deterministic demands through a set of distribution centers. The products can be stored in second and third levels facilities. The product is perishable with a certain shelf life. The product is delivered in a way to be consumed before spoilage. A...

Two-Stage Stochastic Programming Model for Nurse Scheduling with Consideration of Work-force Type

, M.Sc. Thesis Sharif University of Technology Mirzavand Boroujeni, Niloufar (Author) ; Eshghi, Koroush (Supervisor) ; Sadri, Farzaneh (Co-Supervisor)

Abstract

The Nurse Scheduling Problem (NSP), is one of the most complicated problem in health care management systems. The problem is to determine a work schedule by considering some requirements such as governmental policies, staff and their managers satisfaction, etc. Nowadays, while the demand of treatment centers for nurses has increased especially in hospitals, the population of qualified nurses has decreased. In such a fuzzy situation, the managers of the treatment centers want a better nurse scheduling in order to increase the quality of giving services to their patients and consequently increase their income. In this thesis, a two-stage nurse scheduling problem with uncertainties in...

Extension of α[alpha]-labelings of quadratic graphs [electronic resource]

, Article International Journal of Mathematics and Mathematical Sciences ; Issue: 9-12 , 2004 , page 571-578 Eshghi, K ; Sharif University of Technology

2004

Abstract

In this paper, all graphs are finite without loops or multiple edges, and all parameters are positive integers. The symbols |A|, Pn, and Cn denote the cardinality of set A, a snake, and a cycle with n edges, respectively. A sequence of numbers in parentheses or square brackets indicates the labels of vertices of a graph or subgraph under consideration according to whether it is a snake or cycle, respectively

A fuzzy random minimum cost network flow programming problem [electronic resource]

, Article Journal of Industrial and Systems Engineering (JISE)-Iranian Institute of Industrial Engineering ; Article 3, Volume 6, Issue 1, Spring 2012, Page 34-47 Nematian, J. (Javad) ; Eshghi, Kourosh ; Sharif University of Technology

Abstract

In this paper, a fuzzy random minimum cost flow problem is presented. In this problem, cost parameters and decision variables are fuzzy random variables and fuzzy numbers respectively. The object of the problem is to find optimal flows of a capacitated network. Then, two algorithms are developed to solve the problem based on Er-expected value of fuzzy random variables and chance-constrained programming. Furthermore, the results of two algorithms will be compared. An illustrative example is also provided to clarify the concept

Price competition in duopoly supply chains with stochastic demand [electronic resource]

, Article Journal Of Manufacturing Systems ; 01/2014 Mahmoodi, A. (Anvar) ; Eshghi, Kourosh ; Sharif University of Technology

Abstract

In the literature, substantial researches have been carried out on supply chain coordination. The majority of these studies suggest a mechanism that enforces the supply chain members to follow the strategies that produce the equilibrium of an integrated supply chain. Moreover, most of researches do not consider the competition among supply chains

An efficient tabu search algorithm for the single row facility location problem [electronic resource]

, Article European Journal Of Operational Research ; Vol. 205, No. 1, pp. 98-105 Samarghandi, H. (Hamed) ; Eshghi, Kourosh ; Sharif University of Technology

Abstract

The general goal of the facility layout problem is to arrange a given number of facilities to minimize the total cost associated with the known or projected interactions between them. One of the special classes of the facility layout problem is the Single Row Facility Layout Problem (SRFLP), which consists of finding an optimal linear placement of rectangular facilities with varying dimensions on a straight line. This paper first presents and proves a theorem to find the optimal solution of a special case of SRFLP. The results obtained by this theorem prove to be very useful in reducing the computational efforts when a new algorithm based on tabu search for the SRFLP is proposed in this...

Sensitivity analysis of matching pennies game [electronic resource]

, Article Mathematical and Computer Modelling ; Volume 51, Issues 5–6, March 2010, Pages 722–735 Yarmand, H. (Hamed) ; Eshghi, Kourosh ; Sharif University of Technology

Abstract

In this paper, we have discussed the results of sensitivity analysis in a payoff matrix of the Matching Pennies game. After representing the game as a LP model, the sensitivity analysis of the elements of the payoff matrix is presented. The game value and the optimal strategies for different values of parameters are determined and compared

An ACO algorithm for the graph coloring problem [electronic resource]

, Article Computational Intelligence Methods and Applications, ICSC Congress on ; 2005 Salari, M. (Majid) ; Eshghi, Kourosh ; Sharif University of Technology

Abstract

Ant colony optimization (ACO) is a well-known metaheuristic in which a colony of artificial ants cooperate in exploring good solutions to a combinatorial optimization problem. In this paper, an ACO algorithm is presented for the graph coloring problem. This ACO algorithm conforms to max-min ant system structure and exploits a local search heuristic to improve its performance. Experimental results on DIMACS test instances show improvements over existing ACO algorithms of the graph coloring problem

A hybrid SA/TS algorithm for graph coloring problem [electronic resource]

, Article International Journal of Operational Research (IJOR) ; Volume 11, Number 2/2011 Pages 136-159 Pahlavani, A. (Ali) ; Eshghi, Kourosh ; Sharif University of Technology

Abstract

The graph colouring problem, as an important NP-complete problem, is considered in this paper and a hybrid meta-heuristic approach is developed to solve it. The initial solution of the algorithm, generated by a heuristic method, is used by a simulated annealing (SA) approach to generate new solutions until no progress in a number of solutions reported. At this stage, the algorithm will use a tabu search routine and this local search operator will be followed for some iterations. After finding a better solution, the algorithm is again followed through SA. Efficiency of the algorithm is showed through various experiments on well-known benchmark problems of DIMACS. Comparison with the available...

A revised version of ACO for cutting stock problem [electronic resource]

, Article International Journal of Industrial Engineering ; Vol 15, No 4 (2008), Pages 341-348 Eshghi, K. (Kourosh) ; Javanshir, Hassan ; Sharif University of Technology

Abstract

The one-dimensional cutting stock problem has many applications in industries and during the past few years has been one of the centers of attention among the researchers in the field of applied operations research. In this paper, a revised version of Ant Colony Optimization (ACO) technique is presented to solve this problem. This paper is a sequel to the previous ACO algorithm presented by the authors. In this algorithm, according to some probabilistic rules, artificial ants will select cutting patterns and generate a feasible solution. Computational results show the high efficiency and accuracy of the proposed algorithm for solving one- dimensional cutting stock problem

An algorithm for finding a feasible solution of graph labeling problems [electronic resource]

, Article Utilitas Mathematica Publishing Incorporated ; 2007, Vol. 72, pp. 163-174 Eshghi, K. (Kourosh) ; Azimi, Parham ; Sharif University Of Technology

Abstract

Graceful labeling is one of the best known labeling methods of graphs. Despite the large number of papers published on the subject of graph labeling, there are few particular techniques to be used by researchers to gracefully label graphs. In this paper, first a new approach based on the mathematical programming technique is presented to model the graceful labeling problem. Then a “branching method” is developed to solve the problem for special classes of graphs. Computational results show the efficiency of the proposed algorithm for different classes of graphs. One of the interesting results of our model is in the class of trees. The largest tree known to be graceful has at most 27 vertices...

Special classes of mathematical programming models with fuzzy random variables [electronic resource]

, Article Journal of Intelligent and Fuzzy Systems, Published In: IOS Press ; Volume 19, Number 2, 2008 Eshghi, K. (Kourosh) ; Nematian, Javad ; Sharif University of Technology

Abstract

In this paper, we will discuss two special classes of mathematical programming models with fuzzy random variables. In the first model, a linear programming problem with fuzzy decision variables and fuzzy random coefficients is introduced. Then an algorithm is developed to solve the model based on fuzzy optimization method and fuzzy ranking method. In the second model, a fuzzy random quadratic spanning tree problem is presented. Then the proposed problem is formulated and solved by using the scalar expected value of fuzzy random variables. Furthermore, illustrative numerical examples are also given to clarify the methods discussed in this paper

Applications of mathematical programming in graceful labeling of graphs [electronic resource]

, Article Journal of Applied Mathematics (Published by Hindawi) ; Vol. 10, No. 10, pp. 1-8 Eshghi, K. (Kourosh) ; Azimi, Parham ; Sharif University of Technology

Abstract

Graceful labeling is one of the best known labeling methods of graphs. Despite the large number of papers published on the subject of graph labeling, there are few particular techniques to be used by researchers to gracefully label graphs. In this paper, first a new approach based on the mathematical programming technique is presented to model the graceful labeling problem. Then a “branching method” is developed to solve the problem for special classes of graphs. Computational results show the efficiency of the proposed algorithm for different classes of graphs. One of the interesting results of our model is in the class of trees. The largest tree known to be graceful has at most 27 vertices...

A game theory approach for optimal routing: in wireless sensor networks [electronic resource]

, Article Published in: Wireless Communications Networking and Mobile Computing (WiCOM), 2010 6th International Conference on ; (2013), Vol. 3, No. 3, pp. 62-75 Arisian, B. (Babak) ; Eshghi, Kourosh ; Sharif University of Technology

Abstract

In this paper, a "Game Theory" approach for finding an optimal path in a "Wireless Sensor Network" is discussed. WSN is one of the most interesting research fields in the communication networks, and is the center of attention in recent years. In our model, a pricing and payment technique is presented to obtain an optimal path in a WSN by considering reliability, energy and traffic load. The proposed algorithm is able to find a path which improves network lifetime, load distribution and path reliability

An ACO algorithm for one-dimensional cutting stock problem [electronic resource]

, Article Journal of Industrial engineering International ; September 2005, Vol. 1, No. 1, pp. 10-19 Eshghi, K. (Kourosh) ; Javanshir, H ; Sharif University of Technology

Abstract

The one-dimensional cutting stock problem, has so many applications in lots of industrial processes and during the past few years has attracted so many researchers’ attention all over the world. In this paper a metaheuristic method based on ACO is presented to solve this problem. In this algorithm, based on designed probabilistic laws, artificial ants do select various cuts and then select the best patterns. Also because of the problem framework, effective improvements has been made to problem solving process. The results of that algorithm in sample problems, show high efficiency of the algorithm in different levels of problems

Ant colony algorithm for the shortest loop design problem [electronic resource]

, Article Computers and Industrial Engineering, Elsevier ; Volume 50, Issue 4, August 2006, Pages 358–366 Eshghi, K. (Kourosh) ; Kazemi, Morteza ; Sharif University of Technology

Abstract

In this paper, a new algorithm for solving the shortest loop design problem is presented. The shortest loop design problem is to find the shortest loop for an automated guided vehicle covering at least one edge of each department of a block layout. In this paper, first it is shown that this problem can be represented as a graph model. The properties of the presented model enable us to design a meta-heuristic based on ant colony system algorithm for solving the shortest loop design problem. Computational results show the efficiency of our algorithm in compare to the other techniques