Loading...
Search for: mahdavi--i
0.111 seconds

    A modified ant colony system for finding the expected shortest path in networks with variable arc lengths and probabilistic nodes

    , Article Applied Soft Computing Journal ; Vol. 21, issue , August , 2014 , p. 491-500 Farhanchi, M ; Hassanzadeh, R ; Mahdavi, I ; Mahdavi-Amiri, N ; Sharif University of Technology
    2014
    Abstract
    The problem of finding the expected shortest path in stochastic networks, where the presence of each node is probabilistic and the arc lengths are random variables, have numerous applications, especially in communication networks. The problem being NP-hard we use an ant colony system (ACS) to propose a metaheuristic algorithm for finding the expected shortest path. A new local heuristic is formulated for the proposed algorithm to consider the probabilistic nodes. The arc lengths are randomly generated based on the arc length distribution functions. Examples are worked out to illustrate the applicability of the proposed approach  

    A genetic algorithm for optimization problems with fuzzy relation constraints using max-product composition

    , Article Applied Soft Computing Journal ; Volume 11, Issue 1 , 2011 , Pages 551-560 ; 15684946 (ISSN) Hassanzadeh, R ; Khorram, E ; Mahdavi, I ; Mahdavi Amiri, N ; Sharif University of Technology
    2011
    Abstract
    We consider nonlinear optimization problems constrained by a system of fuzzy relation equations. The solution set of the fuzzy relation equations being nonconvex, in general, conventional nonlinear programming methods are not practical. Here, we propose a genetic algorithm with max-product composition to obtain a near optimal solution for convex or nonconvex solution set. Test problems are constructed to evaluate the performance of the proposed algorithm showing alternative solutions obtained by our proposed model  

    A genetic optimization algorithm and perceptron learning rules for a bi-criteria parallel machine scheduling

    , Article Journal of the Chinese Institute of Industrial Engineers ; Volume 29, Issue 3 , 2012 , Pages 206-218 ; 10170669 (ISSN) Fazlollahtabar, H ; Hassanzadeh, R ; Mahdavi, I ; Mahdavi Amiri, N ; Sharif University of Technology
    2012
    Abstract
    This work considers scheduling problems minding the setup and removal times of jobs rather than processing times. For some production systems, setup times and removal times are so important to be considered independent of processing times. In general, jobs are performed according to the automatic machine processing in production systems, and the processing times are considered to be constant regardless of the process sequence. As the human factor can influence the setup and removal times, when the setup process is repetitive the setup times decreases. This fact is considered as learning effect in scheduling literature. In this study, a bi-criteria m-identical parallel machines scheduling... 

    A DEA approach for comparing solution efficiency in U-line balancing problem using goal programming

    , Article International Journal of Advanced Manufacturing Technology ; Volume 61, Issue 9-12 , August , 2012 , Pages 1161-1172 ; 02683768 (ISSN) Farkhondeh, H ; Hassanzadeh, R ; Mahdavi, I ; Mahdavi Amiri, N ; Sharif University of Technology
    Springer  2012
    Abstract
    Line balancing problem plays an important role in the decision making process to increase efficiency and productivity. Recently, U-shaped layout in many production lines has replaced the traditional straight line layout using just-in-time concept. Here, we propose a model, using multi-objective decision making approach to the U-shaped line balancing problem, to offer enhanced decision maker flexibility, by allowing for conflicting goals. The assembly line operation efficiency is the most significant aim in our study, and this efficiency relates to management of resources and the solution of line balancing problem. First, the U-shaped line balancing problem is solved considering the model's... 

    Reserve capacity of mixed urban road networks, network configuration and signal settings

    , Article Intelligent Transportation and Planning: Breakthroughs in Research and Practice ; February , 2018 , Pages 883-906 ; 9781522552116 (EISBN) Divsalar, M ; Hassanzadeh, R ; Mahdavi, I ; Mahdavi Amiri, N ; Sharif University of Technology
    IGI Global  2018
    Abstract
    The authors formulate the transportation mixed network design problem (MNDP) as a mixed-integer bi-level mathematical problem, based on the concept of reserve capacity. The upper level goal is to maximize the reserve capacity by signal settings at intersections, determine street direction and increase street capacities via addition of lanes. The lower level problem is a deterministic user equilibrium traffic assignment problem to minimize the user travel time. The model being non-convex, meta-heuristic methods are used to solve the problem. A hybridization of genetic algorithm with simulated annealing and a bee algorithm are proposed. Numerical examples are illustrated to verify the... 

    Toward sustainable optimization with stackelberg game between green product family and downstream supply chain

    , Article Sustainable Production and Consumption ; Volume 23 , 2020 , Pages 198-211 Pakseresht, M ; Shirazi, B ; Mahdavi, I ; Mahdavi Amiri, N ; Sharif University of Technology
    Elsevier B.V  2020
    Abstract
    Green products are increasingly considered by companies, owing to the significant attention of government regulations, customers’ requests and competitors. Here, we deal with Green Product Families (GPFs) by selecting green components, modules and products which are produced based on the assembling to order (ATO) approach to cover diverse customer needs. Designing a GPFs is important but not sufficient for sustainable optimization. In fact, we need to simultaneously consider the supply chain of a GPF to control the pollution generated in the downstream supply chain. For a sustainable optimization approach, this joint configuration is usually structured based on economic, environmental and... 

    A model for the time dependent vehicle routing problem with time windows under traffic conditions with intelligent travel times

    , Article RAIRO - Operations Research ; Volume 55, Issue 4 , 2021 , Pages 2203-2222 ; 03990559 (ISSN) Khanchehzarrin, S ; Shahmizad, M ; Mahdavi, I ; Mahdavi Amiri, N ; Ghasemi, P ; Sharif University of Technology
    EDP Sciences  2021
    Abstract
    A new mixed-integer nonlinear programming model is presented for the time-dependent vehicle routing problem with time windows and intelligent travel times. The aim is to minimize fixed and variable costs, with the assumption that the travel time between any two nodes depends on traffic conditions and is considered to be a function of vehicle departure time. Depending on working hours, the route between any two nodes has a unique traffic parameter. We consider each working day to be divided into several equal and large intervals, termed as a time interval of traffic. Here, allowing for long distances between some of the nodes, travel time may take more than one time interval of traffic,... 

    A genetic algorithm for a creativity matrix cubic space clustering: A case study in Mazandaran Gas Company

    , Article Applied Soft Computing Journal ; Volume 13, Issue 4 , 2013 , Pages 1661-1673 ; 15684946 (ISSN) Aalaei, A ; Fazlollahtabar, H ; Mahdavi, I ; Mahdavi Amiri, N ; Yahyanejad, M. H ; Sharif University of Technology
    2013
    Abstract
    Creativity is a promoting factor in organizations. Having employees in structured and organized configurations in a creative manner, helps in improving the productivity. We investigate different structural aspects of teams' network organization and the creativity within a knowledge development program (KDP). The proposed methodology being equipped with a heuristic clustering technique, classifies the employees with respect to creativity parameters and configures a creativity matrix. Applying the creativity matrix, clustering is performed via mathematical programming. For large problems, a genetic algorithm (GA) is developed to solve the mathematical model. We also employ the Taguchi method... 

    A heuristic methodology for multi-criteria evaluation of web-based e-learning systems based on user satisfaction

    , Article Journal of Applied Sciences ; Volume 8, Issue 24 , 2008 , Pages 4603-4609 ; 18125654 (ISSN) Mahdavi, I ; Fazlollahtabar, H ; Heidarzade, A ; Mahdavi Amiri, N ; Rooshan, Y. I ; Sharif University of Technology
    2008
    Abstract
    Web-based E-Leaning Systems (WELSs) have emerged as new means of skill training and knowledge acquisition, encouraging both academia and industry to invest resources in the adoption of these systems. Traditionally, most pre- and post-adoption tasks related to evaluation are carried out from the viewpoints of technology. Since users have been widely recognized as being a key group of stakeholders in influencing the adoption of information systems, their attitudes about these systems are considered as pivotal. Therefore, based on the theory of multi-criteria decision making and the research results concerning user satisfaction in the fields of human-computer interaction and information... 

    A multiobjective integrated multiproject scheduling and multiskilled workforce assignment model considering learning effect under uncertainty

    , Article Computational Intelligence ; Volume 36, Issue 1 , February , 2020 , Pages 276-296 Hematian, M ; Seyyed Esfahani, M. M ; Mahdavi, I ; Mahdavi Amiri, N ; Rezaeian, J ; Sharif University of Technology
    Blackwell Publishing Inc  2020
    Abstract
    Today, organizations try to decline academically expenses using humans and resources in addition to rising managers and operators' satisfaction. Meantime, a very important step in the process of decision is the assignment of human resources, particularly in connection with research and development (R&D) projects in which the system is highly dependent on the capabilities of human resources. In this study, we tried all the assumptions that come true in the real world, considered a model for applied R&D projects to reduce costs and increase the efficiency of projects. Therefore, an integrated multiproject scheduling and multiskill human resource assignment model under uncertainty has developed... 

    No-wait flow shop scheduling using fuzzy multi-objective linear programming

    , Article Journal of the Franklin Institute ; Volume 345, Issue 5 , August , 2008 , Pages 452-467 ; 00160032 (ISSN) Javadi, B ; Saidi Mehrabad, M ; Haji, A ; Mahdavi, I ; Jolai, F ; Mahdavi Amiri, N ; Sharif University of Technology
    2008
    Abstract
    This study develops a fuzzy multi-objective linear programming (FMOLP) model for solving the multi-objective no-wait flow shop scheduling problem in a fuzzy environment. The proposed model attempts to simultaneously minimize the weighted mean completion time and the weighted mean earliness. A numerical example demonstrates the feasibility of applying the proposed model to no-wait flow shop scheduling problem. The proposed model yields a compromised solution and the decision maker's overall levels of satisfaction. © 2008 The#Franklin#Institute  

    A web-based methodology for convergent product fuzzy networks using the Steiner tree

    , Article Journal of Industrial and Production Engineering ; Volume 30, Issue 7 , 2013 , Pages 415-432 ; 21681015 (ISSN) Hassanzadeh, R ; Mahdavi, I ; Mahdavi Amiri, N ; Sharif University of Technology
    2013
    Abstract
    An important manufacturing technology spectrum is to consider rapid and sensitive assemblies through convergent product (CP) in digital environment. We integrate functions and sub-functions using a comprehensive mathematical optimization process. To form the CP, a web-based fuzzy network is considered in which a collection of base functions and sub-functions configure the nodes and each arc in the network is to be a link between two nodes. The aim is to find an optimal tree of functionalities in the network adding value to the product in the web environment. First, a purification process is performed in the product network to assign the links among bases and sub-functions. Then, fuzzy... 

    A web-based multi-optimisation approach for convergent product networks using the Steiner tree

    , Article International Journal of Services and Operations Management ; Vol. 17, issue. 2 , 2014 , pp. 142-167 ; ISSN: 17442370 Hassanzadeh, R ; Mahdavi, I ; Mahdavi-Amiri, N ; Sharif University of Technology
    2014
    Abstract
    We propose a methodology to determine value by adding functionalities for convergent products. A collection of base functions and sub-functions configure the nodes of a web-based (digital) network representing functionalities. Each arc in the network is to be assigned as the link between two nodes. The aim is to find an optimal tree of functionalities in the network adding value to the product in the web environment. First, a purification process is performed in the product network to assign the links among bases and sub-functions. Then, numerical values as benefits and costs are determined for arcs and nodes respectively, using a mathematical approach. Finally, the Steiner tree methodology... 

    Optimal pipe diameter sizing in a tree-structured gas network: A case study

    , Article International Journal of Industrial and Systems Engineering ; Volume 12, Issue 3 , 2012 , Pages 346-368 ; 17485037 (ISSN) Mohajeri, A ; Mahdavi, I ; Mahdavi Amiri, N ; Sharif University of Technology
    2012
    Abstract
    We design an optimal pipe diameter sizing in a tree-structured natural gas network. Design of pipeline, facility and equipment systems are necessary tasks to configure an optimal natural gas network. A mixed-integer programming model is formulated to minimise the total cost in the network. The aim is to optimise pipe diameter sizes so that the location-allocation cost is minimised. Pipeline systems in natural gas network must be designed based on gas flow rate, length of pipe, gas maximum drop pressure allowance and gas maximum velocity allowance. We use information based on relationship among gas flow rates and pipe diameter sizes considering gas pressure and velocity restrictions. We apply... 

    ICoSim-FMS: An intelligent co-simulator for the adaptive control of complex flexible manufacturing systems

    , Article Simulation Modelling Practice and Theory ; Volume 19, Issue 7 , August , 2011 , Pages 1668-1688 ; 1569190X (ISSN) Shirazi, B ; Mahdavi, I ; Mahdavi Amiri, N ; Sharif University of Technology
    2011
    Abstract
    We describe an intelligent co-simulator for real time production control of a complex flexible manufacturing system (CFMS) having machine and tool flexibility. The manufacturing processes associated with the CFMS are complicated with each operation being possibly done by several machining centers. The co-simulator design approach is built upon the theory of dynamic meta-model based supervisory control with the cooperation of its own embedded intelligent blocks. The system is implemented by coupling of the centralized simulation controller (CSC) and real-time simulator for enforcing dynamic strategies of shop floor control. The posteriori adaptive co-simulator is equipped with a concurrent... 

    A nonlinear model for a capacitated random transportation network

    , Article Journal of Industrial and Production Engineering ; Oct , 2015 , Page 500-515 ; 21681015 (ISSN) Shiripour, S ; Mahdavi Amiri, N ; Mahdavi, I ; Sharif University of Technology
    Taylor and Francis Ltd  2015
    Abstract
    In this study, we consider a capacitated location–multi-allocation–routing problem with population-dependent random travel times. The objective is to find appropriate locations as server locations among the candidate locations, allocate the existing population in each demand node to server locations, and determine the movement path of each member to reach its corresponding server with respect to the simultaneous change of the random travel times so that the expected total transportation time is minimized. In our study, the concept of population-dependent random travel times incurs two issues: (1) consideration of some random factors in computing the travel times and (2) impact of the... 

    Planning a capacitated road network with flexible travel times: a genetic algorithm

    , Article Journal of Mathematical Modelling and Algorithms in Operations Research ; Volume 14, Issue 4 , December , 2015 , Pages 425-451 ; 2214-2487 (ISSN) Shiripour, S ; Mahdavi Amiri, N ; Mahdavi, I ; Sharif University of Technology
    Botanical Society of America Inc  2015
    Abstract
    We are concerned with a capacitated location-multi allocation-routing problem in a road network with flexible travel times. It is assumed that all links are two-way and capacities of the server nodes and arcs for accepting of population are limited. The aim of our work is to find numbers and locations of server nodes, allocation of the existing population in existing demand nodes on the network to the servers and the allocation of existing population in each node to different routes to determine the decided server for each member so that total transportation time is minimized. Here, two basic concepts are considered: multi allocation and flexible travel times. The concept of multi allocation... 

    Multiple attribute group decision making in interval type-2 fuzzy environment using a new distance formulation

    , Article International Journal of Operational Research ; Volume 24, Issue 1 , 2015 , Pages 17-37 ; 17457645 (ISSN) Heidarzade, A ; Mahdavi, I ; Mahdavi Amiri, N ; Sharif University of Technology
    Inderscience Enterprises Ltd  2015
    Abstract
    Type-2 fuzzy sets are generalisations of ordinary fuzzy sets in which the membership grades are characterised by fuzzy membership functions. Here, we consider the problem of finding the distance between two interval type-2 fuzzy sets (IT2-FSs). We define the formulation of calculating the distance between two IT2-FSs based on a new definition of centroid for an IT2-FS and explain an algorithm for obtaining it. Then, based on our proposed distance formulation, we present a method to deal with fuzzy multiple attributes group decision-making (FMAGDM) problems. We also use two examples to illustrate the FMAGDM process of the proposed method. The method provides us with a useful way to deal with... 

    A heuristic zero/one programming for a bi-objective web-based convergent product networks

    , Article International Journal of Advanced Operations Management ; Volume 7, Issue 1 , 2015 , Pages 63-84 ; 1758938X (ISSN) Hassanzadeh, R ; Mahdavi, I ; Mahdavi Amiri, N ; Sharif University of Technology
    Inderscience Enterprises Ltd  2015
    Abstract
    In the proposed work, by applying the Steiner tree, a bi-objective mathematical model is developed to consider promotion of convergent products to satisfy two objectives of cost and benefit. The results are some new products with more utility for both the buyer and the producer. The methodology proposed to determine value adding functionalities for convergent products. A collection of base functions and sub-functions configure the nodes of a web-based (digital) network representing functionalities. Each arc in the network is to be assigned as the link between two nodes. The aim is to find an optimal tree of functionalities in the network adding value to the product in the web environment.... 

    Optimal location-multi-allocation-routing in capacitated transportation networks under population-dependent travel times

    , Article International Journal of Computer Integrated Manufacturing ; Volume 29, Issue 6 , 2016 , Pages 652-676 ; 0951192X (ISSN) Shiripour, S ; Mahdavi Amiri, N ; Mahdavi, I ; Sharif University of Technology
    Taylor and Francis Ltd  2016
    Abstract
    A capacitated location-multi-allocation-routing model is presented for a transportation network with travel times between the nodes represented by links on the network. The concept of multi-allocation arises from the possibility of allocating the population in a demand node to more than one server node. In normal conditions, travel time between two nodes is a fixed value. However, since the flow of population in a link can affect the travel time, here the impact of the population flow on link time is considered to be simultaneous. This way, distribution of the population over the network has a direct influence on the travel link times. It is assumed that all links are two-way and capacities...