Research Paper Engineering Optimization
1. Determination of Optimum Smoothing Constant of Single Exponential Smoothing Method: A Case Study

C. L. Karmaker

Volume 6, Issue 3 , Autumn 2017, Pages 184-192

http://dx.doi.org/10.22105/riej.2017.49603

Abstract
  Exponential smoothing is a sophisticated forecasting method that works based on previous forecast plus a percentage of the forecast error. A key issue of this technique is the proper choice of exponential smoothing constant. In order to minimize forecasting errors, choosing an appropriate value of smoothing ...  Read More

Research Paper Data Envelopment Analysis, DEA
2. Determine the Efficiency of Time Depended Units by Using Data Envelopment Analysis

Z. Taeb; F. Hosseinzadeh Lotfi; S. Abbasbandy

Volume 6, Issue 3 , Autumn 2017, Pages 193-201

http://dx.doi.org/10.22105/riej.2017.49156

Abstract
  In the last years, several techniques have been reported for managing a system and recognition of the related decision making units. One of them is based on mathematical modeling. Efficiency of any system is very important for all decision makings. Often applied data have time dependent inputs/ outputs. ...  Read More

Research Paper Operations Research
3. A MOLFP Method for Solving Linear Fractional Programming Under Fuzzy Environment

S.K. Das; T. Mandal

Volume 6, Issue 3 , Autumn 2017, Pages 202-213

http://dx.doi.org/10.22105/riej.2017.92950.1002

Abstract
  In this paper, a solution procedure is proposed to solve Fully Fuzzy Linear Fractional Programming (FFLFP) problem where all the variables and parameters are triangular fuzzy numbers. Here, FFLFP problem transformed into an equivalent Multi- Objective Linear Fractional Programming (MOLFP) problem. Then ...  Read More

Research Paper Fuzzy optimization
4. A New Method for Solving Fully Fuzzy Multi Objective Supplier Selection Problem

H. Nasseri; M. Morteznia; M. Mirmohseni

Volume 6, Issue 3 , Autumn 2017, Pages 214-227

http://dx.doi.org/10.22105/riej.2017.91532.1000

Abstract
  Supplier selection is one of the most critical activities of purchasing management in a supply chain. Because selecting right suppliers helps reduce purchasing costs, improve quality of final products and services, etc. In a real situation, for a supplier selection problem, most of the input information ...  Read More

Research Paper Case studies in industry and services
5. Concessioning a Strategy for Enhancing Nigeria’s Airport Operational Efficiency - Lessons from Developed Countries

A. O Adeniran; K. T. Gbadamosi

Volume 6, Issue 3 , Autumn 2017, Pages 228-245

http://dx.doi.org/10.22105/riej.2017.97500.1013

Abstract
  This study examines some concessioned airports in the developed countries and their operational performance level with a view to identifying the positive impact of concessioning on their growth, development and operational performance. The ultimate goal of the study is to provide basis for adapting the ...  Read More

Research Paper Mathematical modelling
6. Influence of Wall Properties on the Peristaltic Flow of a Jeffrey Fluid in a Uniform Porous Channel under Heat Transfer

G. C. Sankad; P. S. Nagathan

Volume 6, Issue 3 , Autumn 2017, Pages 246-261

http://dx.doi.org/10.22105/riej.2017.98628.1014

Abstract
  Incompressible Jeffrey fluid under peristalsis is considered into permeable conduit. Magnetic effect and slip effect are studied for this channel in the existence of wall slip and heat transfer. Time average velocity, heat transfer coefficient and temperature are obtained analytically underneath the ...  Read More

Research Paper Total quality management and quality engineering
7. Removal of Copper Ions from Liquid Wastes by Adsorption Technique

E. Nassef; A. Mahmoud; H. Salah; Y. El-taweel

Volume 6, Issue 3 , Autumn 2017, Pages 255-268

http://dx.doi.org/10.22105/riej.2017.101704.1026

Abstract
  The present study aims to removal of copper ions (Cu2+) as a heavy metal ion from aqueous solution by a high inorganic molecular weight compound. This compound is modified clay (activated bentonite) which is used in oil well drilling, and obtained from local company. The experimental results showed that ...  Read More