eng
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
2018-02-01
25
1
339
358
10.24200/sci.2017.4399
4399
A flexible cell scheduling problem with automated guided vehicles and robots under energy-conscious policy
Mohammad Hemmati Far
m.hemmatifar@gmail.com
1
Hassan Haleh
hhaleh@gut.ac.ir
2
Abbas Saghaei
a.saghaei@srbiau.ac.ir
3
Department of Industrial Engineering, Science and Research branch, Islamic Azad University, Tehran, Iran
Department of Industrial & Mechanical Engineering, Islamic Azad University, Qazvin Branch, Qazvin, Iran
Department of Industrial Engineering, Science and Research branch, Islamic Azad University, Tehran, Iran
A flexible cell scheduling problem (CSP) under time-of-use (TOU) electricity tariffs are developed in this study. To apply a kind of energy-conscious policy, over cost of on-peak period electricity consumption, limitations on total energy consumption by all facilities, set up time available on each cell, part defect (pert) percentage and the total number of automated guided vehicles (AGV) are considered. Additionally, an ant colony optimization (ACO) algorithm is employed to find a near-optimum solution of proposed mixed integer linear programming (MILP) model with the objective of minimizing the total cost of CSP model. Since no benchmark is available in the literature, a lower bound is implemented as well to validate the result achieved. Moreover, to improve the quality of the results obtained by meta-heuristic algorithms, two hybrid algorithms (HGA and HACO) was proposed to solve the model. For parameter tuning of algorithms, Taguchi experimental design method is applied. Then, numerical examples are presented to prove the application of the proposed methodology. Our results compared with the lower bound and as a result it confirmed that HACO was capable to find better and nearer optimal solutions.
https://scientiairanica.sharif.edu/article_4399_1221f23e396b45db6c5700120db4f480.pdf
Cell-scheduling
Automated guided vehicles (AGV)
Robots
Energy-conscious policy
Ant colony optimization (ACO)
genetic algorithm (GA)
Taguchi experimental design method
eng
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
2018-02-01
25
1
359
369
10.24200/sci.2017.4407
4407
RENEWABLE POLICIES AND CHALLENGES BY 2020 IN GREECE: A QUESTIONNAIRE SURVEY
Aristidis Bitzenis
1
Panagiotis Kontakos
pkontakos@uclan.ac.uk
2
Charisios Kafteranis
3
Department of International and European Studies, University of Macedonia, Research Leader of European Research Fund Thalis, 156 Egnatias Str., GR 54006, Greece
School of Business & Management, University of Central Lancashire, 12-14 University Avenue, CY 7080, Cyprus; Postdoctoral Researcher under Thales Program at the University of Macedonia, Greece
University of Macedonia, Researcher under Thales Program, Department of International and European Studies, University of Macedonia, 156 Egnatias Str., GR 54006, Greece
In a notable change from the position in the past, the Greek government is committed to greening the economy and has assumed determined policies and actions to boost the utilization of renewable energy. The aim of the paper is, firstly, to present the latest developments of the renewable energy policy in Greece, the current achievements and impediments in the implementation of planned reforms in the accomplishment of its 2020 targets, and the specific policy measures introduced; second, to discuss the pace of respective developments in other EU-28 member countries; and, third, through a questionnaire survey and stratified interviews with market participants, to verify the achievements of the government towards reversing previous bureaucratic and prone to corruption procedures. Respectively, research survey results from our survey and interviews conducted in the second semester of 2014 are presented. The majority of respondents expect that the targets set in the National Renewable Energy Action Plan will be reached by 2020. The paper and the questionnaire survey have been conducted under the auspices of the European research program THALES, which intends to measure various aspects of the shadow economy in Greece, also including the areas of renewable energy trade and finance.
https://scientiairanica.sharif.edu/article_4407_cf612b783df6842c716132ba8a2406e0.pdf
Renewable Energy
government policy
questionnaire survey
shadow economy
Greece
eng
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
2018-02-01
25
1
370
385
10.24200/sci.2017.4408
4408
Single machine scheduling to minimize the maximum tardiness under piecewise linear deteriorating jobs
Abbas-Ali Jafari
a.jafari@stu.yazd.ac.ir
1
M. M. Lotfi
2
Department of Industrial Engineering, Faculty of Engineering, Yazd University, Yazd, Iran
Department of Industrial Engineering, Faculty of Engineering, Yazd University, Yazd, Iran
In many realistic production environments, jobs will take longer time if they begin later. This phenomenon is known as deteriorating jobs which have widely been studied. In this paper, the piecewise linear deterioration is discussed in a single machine scheduling problem of minimizing the maximum tardiness. After proving the NP-hardness of problem, a Branch and Bound and a heuristic algorithm with O(n2) are proposed for solving the large scale problems to near optimal solutions. The heuristic approach is also used to determine an upper bound on the solution of B&B algorithm. The computational results for evaluating performance of the two algorithms confirm the excellent performance of B&B algorithm as it is able to solve the problems with at least 32 jobs within a reasonable time. Notably, the heuristic approach is quite accurate and efficient with an average error percentage of less than 0.3%.
https://scientiairanica.sharif.edu/article_4408_ade9762f2cb7a30e00e16179d788070f.pdf
Scheduling
Piecewise linear deteriorating jobs
single machine
Tardiness
Branch and Bound
Heuristic
eng
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
2018-02-01
25
1
386
397
10.24200/sci.2017.4412
4412
A proposal for modeling and simulating correlated discrete Weibull variables
A. Barbiero
1
Department of Economics, Management and Quantitative Methods, 4 Universit`a degli Studi di Milano, via Conservatorio 7, 20122 Milan, Italy
Researchers in applied sciences are often concerned with multivariate random vari9ables. In particular, multivariate discrete data often arise in many fields (statistical10 quality control, biostatistics, failure and reliability analysis, etc.) and modeling such11 data is a relevant task, as well as simulating correlated discrete data satisfying some spe12cific constraints. Here we consider the discrete Weibull distribution as an alternative to13 the popular Poisson random variable and propose a procedure for simulating correlated14 discrete Weibull random variables, with marginal distributions and correlation matrix as15signed by the user. The procedure indeed relies upon the Gaussian copula model and an16 iterative algorithm for recovering the proper correlation matrix for the copula ensuring17 the desired correlation matrix on the discrete margins. A simulation study is presented,18 which empirically assesses the performance of the procedure in terms of accuracy and19 computational burden, also in relation to the necessary (but temporary) truncation of20 the support of the discrete Weibull random variable. Inferential issues for the proposed21 model are also discussed and are eventually applied to a dataset taken from the literature,22 which shows that the proposed multivariate model can satisfactorily fit real-life correlated23 counts even better than the most popular or recent existing ones.
https://scientiairanica.sharif.edu/article_4412_d1dadf84d563de50f658d597d2900c4c.pdf
correlated counts
Gaussian copula
parameter estimation
stochastic simulation
eng
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
2018-02-01
25
1
398
409
10.24200/sci.2017.4413
4413
The NDEA–MOP Model in the Presence of Negative Data Using Fuzzy Method
Kianoosh Kianfar
kianfarkianoosh62@gmail.com
1
Mahnaz Ahadzadeh Namin
mahnazahadzadehnamin@gmail.com
2
Akbar Alam Tabriz
a-tabriz@sbu.ac.ir
3
Esmaeil Najafi
4
Farhad Hosseinzadeh Lotfi
farhad@hosseinzadeh.ir
5
Department of Industrial Engineering, Science and Research branch, Islamic Azad University, Tehran, Iran.
Department of Mathematics, Shahr-e-Qods Branch, Islamic Azad University, Tehran, Iran
Department of Management, Shahid Beheshti University, Tehran, Iran
Department of Industrial Engineering, Science and Research branch, Islamic Azad University, Tehran, Iran
Department of Mathematics, Science and Research branch, Islamic Azad University, Tehran, Iran
In this study, the multi-objective programming (MOP) method was used to solve network DEA (NDEA) models with assumption that, negative data is considered for the proposed NDEA model which consists of semi-negative and semi-positive input and output. At first, two stage and then k stage production models were formulated with consideration of negative data. In the multi-objective programming, two separate objective functions including the divisional efficiencies and the overall efficiency of the organization are modeled. In comparison to conventional DEA with negative data, the advantage of the proposed NDEA models is consideration of intermediate processes and products, in order to calculate the organization's overall efficiency. However, in conventional DEA, sub-stages of the organizations are neglected. To measure the efficiencies of an organization regarding interactive internal process, two case studies were investigated by application of the NDEA-MOP method with negative data. Case study 1 is focused on units with two stages having semi-negative and semi-positive indexes. In case study 2, units with three stages are evaluated. These units also have semi-negative and semi-positive indexes. The overall efficiency of each unit is calculated using the proposed models. Fuzzy approach as a solution procedure is applied.
https://scientiairanica.sharif.edu/article_4413_83c3c58afe2e36df0e3831c996a1c83d.pdf
Data envelopment analysis
Network DEA
semi-positive data
semi-negative data
overall efficiency
Fuzzy method
eng
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
2018-02-01
25
1
410
430
10.24200/sci.2017.4411
4411
Integrated and Dynamic Design of Sustainable Closed-loop Supply Chain Network Considering Pricing
Arash Nobari
arashnob@yahoo.com
1
Amirsaman Kheirkhah
amirsamankheirkhah@yahoo.com
2
Industrial Engineering Department, Faculty of Engineering, Bu-Ali Sina University, Hamedan, Iran
Industrial Engineering Department, Faculty of Engineering, Bu-Ali Sina University, Hamedan, Iran
In this paper, a novel multi-objective model for dynamic and integrated network design of sustainable closed-loop supply chain network is proposed, which aims to optimize economic, environmental, and social concerns, simultaneously. In order to have a dynamic design, multiple strategic periods are considered during the planning horizon. Furthermore, different short-term decisions are integrated with long-term decisions related to the network design problem. Two of these short-term decisions are determining selling price of products in forward logistics and buying price of used products from customer zones in reverse logistics. Based on the complexity of proposed multi-objective model, a multi-objective imperialist competitive algorithm (MOICA) is proposed to solve the model, and the results are compared with a non-dominated sorting genetic algorithm (NSGA-II). Finally, to evaluate the performance of proposed algorithm, several numerical examples are used, which the results indicate the efficiency of the proposed algorithm.
https://scientiairanica.sharif.edu/article_4411_6b9d84032eb1b6e926b98b7d767a9250.pdf
Dynamic supply chain network design
Integrated planning
Sustainability
Pricing
Pareto-based multi-objective metaheuristic algorithm
eng
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
2018-02-01
25
1
431
449
10.24200/sci.2017.4409
4409
A fuzzy multi-objective multi-product supplier selection and order allocation problem in supply chain under coverage and price considerations: An urban agricultural case study
Alborz Hajikhani
alborz.hajikhani@gmail.com
1
Mohammad Khalilzadeh
2
Seyed Jafar Sadjadi
sjsadjadi@iust.ac.ir
3
Department of Industrial Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran
Department of Industrial Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran
Department of Industrial Engineering, Iran University of Science and Technology, Tehran, Iran
In this paper, a fuzzy multi-objective model is presented to select and allocate the order to the suppliers in uncertainty conditions, considering multi-period, multi-source, and multi-product cases at two levels of a supply chain with pricing considerations. Objective functions considered in this study as the measures to evaluate the suppliers are the purchase, transportation, and ordering costs, timely delivering or deference shipment quality or wastages which are amongst major quality aspects. Partial and general coverage of suppliers in respect of distance and finally suppliers' weights make the amounts of products orders more realistic. Deference and coverage parameters in the model are considered as uncertain and random triangular fuzzy number. Since the proposed mathematical model is NP-hard, multi-objective particle swarm optimization (MOPSO) algorithm is presented. To validate the performance of MOPSO, we applied non-dominated sorting genetic algorithm (NSGA-II). Taguchi technique is executed to tune the parameters of both algorithms. A practical case study in an agricultural industry is shown to demonstrate that the proposed algorithm applies to the real-world problems. The results are analyzed using quantitative criteria, performing parametric, and non-parametric statistical analysis.
https://scientiairanica.sharif.edu/article_4409_f4ce8f549d930d3755477f9dbc0f15f9.pdf
Multi-objective Supplier Selection Problem
Coverage
Fuzzy logic
MOPSO
NSGA-II
eng
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
2018-02-01
25
1
450
465
10.24200/sci.2017.4402
4402
Two-dimensional uncertain linguistic generalized normalized weighted geometric Bonferroni mean and its application to multiple-attribute decision making
Peide Liu
peide.liu@gmail.com
1
School of Management Science and Engineering, Shandong University of Finance and Economics, Jinan Shandong 250014, P.R. of China
2-dimension uncertain linguistic variables (2DULVs) are a powerful tool to express the fuzzy or uncertain information, and the weighted Bonferroni mean can not only take the attribute importance into account but also capture the interrelationship between the attributes. However, the traditional Bonferroni mean can only deal with the crisp numbers. In this paper, Bonferroni mean was extended to process the 2DULVs. Firstly, we proposed the normalized weighted geometric Bonferroni mean (NWGBM) operator and the generalized normalized weighted geometric Bonferroni mean (GNWGBM) operator, which have the characteristics of reducibility and also consider the interrelationships between two attributes. Then we introduced the computation rules, characteristics, the expected value and comparison method of the 2DULVs. Further, we developed the 2-dimension uncertain linguistic normalized weighted geometric Bonferroni mean (2DULNWGBM) and the 2-dimension uncertain linguistic generalized normalized weighted geometric Bonferroni mean (2DULGNWGBM), and explored some properties and discussed some special cases of them. Finally, we developed a new decision making method based on these operators, and an example is given to compare with the existing methods.
https://scientiairanica.sharif.edu/article_4402_b8051d22f0c212ce9e22c1458fc7b312.pdf
Aggregation operators
Multiple attribute decision making
Bonferroni mean
2-dimension uncertain linguistic variables
eng
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
2018-02-01
25
1
466
482
10.24200/sci.2017.4410
4410
Prioritized averaging/geometric aggregation operators under the intuitionistic fuzzy soft set environment
Rishu Arora
1
Harish Garg
harishg58iitr@gmail.com
2
School of Mathematics, Thapar University Patiala 147004, Punjab, India
School of Mathematics, Thapar University Patiala 147004, Punjab, India
Soft set theory acts as a fundamental tool for handling the uncertainty in the data by adding aparameterizations factor during the process as compared to fuzzy and intuitionistic fuzzy set theory.In the present manuscript, the work has been done under the intuitionistic fuzzy soft sets (IFSSs)environment and proposed some new averaging/geometric prioritized aggregation operators in whichthe preferences related to attributes are taken in form of IFSSs. Desirable properties of its have alsobeen investigated. Furthermore, based on these operators, an approach to investigate the multi-criteria decision making (MCDM) problem has been presented. The eectiveness of these operatorshas been demonstrated through a case study.
https://scientiairanica.sharif.edu/article_4410_c7f1e5aa3c69044064c037825329e859.pdf
MCDM
IFSS
Aggregation operator
Decision-Making
eng
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
2018-02-01
25
1
483
491
10.24200/sci.2017.20006
20006
Efficiency assessment of Iranian Handmade Carpet Company by network DEA
S. H. Zegordi
1
A. Omid
2
Industrial Engineering Dept., School of Engineering, Tarbiat Modares University, Al-Ahmad Ave., Tehran, Iran
Industrial Engineering Dept., School of Engineering, Tarbiat Modares University, Al-Ahmad Ave., Tehran, Iran
Different categories of Iranian handmade carpet are produced each year. Since of resource limitation, it is so important for managers to allocate more resources to the most efficient categories. So the main purpose of this illustration is to consider most efficient types of carpet in production and sales stages. To do so, different categories of Iranian handmade carpet are considered as DMUs. This study utilizes network DEA for constructing a model to analyze total and partial efficiency of Iranian Handmade Carpet Company (IHCC) simultaneously. IHCC consists of three main departments that are working jointly to maximize productivity of the firm; therefore, the case of IHCC is a multi-stage system with shared intermediate variables, extra inputs to the second stage and undesired outputs. The novelty of this paper is the methodology used for calculating the efficiency which is based on multi-objective programming. Results of experimental data of IHCC is summarized in order to prepare some brilliant management strategies based on partial and total efficiency scores of different carpet categories. Since the lack of familiar researches in the area of carpet industry efficiency measurement, this research will provide valuable information for decision makers.
https://scientiairanica.sharif.edu/article_20006_188f5670707b362ac58d91ab4d8e1759.pdf
Data envelopment analysis
Efficiency
Multistage
Multi-objective
Network
Undesired outputs