Research Paper Operations Research
1. Multi-objective linear mathematical programming for solving U-shaped robotic assembly line balancing

M. Rabbani; A. H. Khezri; H. Farrokhi-Asl; S. Aghamohamadi-Bosjin

Volume 8, Issue 1 , Spring 2019, Pages 1-16

http://dx.doi.org/10.22105/riej.2019.160247.1067

Abstract
  In recent years, robots have been an eminent solution for manufacturers to facilitate their process and focus on a variety of their products. As the importance of robot usages, our paper focuses on the robotics assembly line. In this paper, we have considered the cycle time, robot operational costs, ...  Read More

Research Paper Game theory
2. On solving two-person zero-sum fuzzy matrix games via linear programming approach

H. A. Khalifa

Volume 8, Issue 1 , Spring 2019, Pages 17-27

http://dx.doi.org/10.22105/riej.2019.170067.1075

Abstract
  In this paper, a two-person zero-sum matrix game with fuzzy numbers payoff is introduced. Using the fuzzy number comparison introduced by Rouben's method (1991), the fuzzy payoff is converted into the corresponding deterministic payoff. Then, for each player, a linear programming problem is formulated. ...  Read More

Research Paper Operations Research
3. Developing 360 degree performance evaluation method for school teachers

M. Movafaghpour

Volume 8, Issue 1 , Spring 2019, Pages 28-39

http://dx.doi.org/10.22105/riej.2019.169895.1074

Abstract
  The purpose of this study is to provide a proper method for evaluating performance of teachers, which leads to authorities awareness about the quality and quantity of activities that are acceptable to the organization; also creating the grounds for empowering human resources, reduction of dissatisfaction, ...  Read More

Research Paper Total quality management and quality engineering
4. Assessing the awareness of local consumer’s product producers towards packaging standards in Tanzania

J. M. Nzumile; I. W. Taifa

Volume 8, Issue 1 , Spring 2019, Pages 40-52

http://dx.doi.org/10.22105/riej.2019.170766.1077

Abstract
  Packaging plays an important role in ensuring that the produced product is well contained, protected, and preserved. Due to its significance, the researcher decided to undertake research aiming at examining the awareness of local producers towards products’ packaging. This research employs a descriptive ...  Read More

Research Paper Systems and service modeling and simulation
5. Stuff scheduling in capillary marketing and analyse of its impact on the company’s financial issues

H. Amin-Tahmasbi; M. Hami

Volume 8, Issue 1 , Spring 2019, Pages 53-65

http://dx.doi.org/10.22105/riej.2019.159489.1066

Abstract
  In today’s competitive business environment, supply chain performance is one of the most critical issues in the various industries; there is much argumentation about the fact that supply chain performance is the basis of the supply chain management efficiency. In this regard, the distribution sector ...  Read More

Research Paper Engineering Optimization
6. Study on the effect of different types of crude oils on the rate of corrosion and the properties of some selected ferrous metals

S. Aluvihara; J. K. Premachandra

Volume 8, Issue 1 , Spring 2019, Pages 66-76

http://dx.doi.org/10.22105/riej.2019.170944.1078

Abstract
  Crude oil is a predominant natural resource and also it causes the metallic corrosion in the industry of crude oil refining due to some corrosive properties of crude oils. In the current research, it is expected to investigate the effect of such compounds of crude oils on the rate of corrosion of seven ...  Read More

Review Paper Other
7. Number theoretic properties of the commutative ring Zn

Sh. Sajana; D. Bharathi

Volume 8, Issue 1 , Spring 2019, Pages 77-88

http://dx.doi.org/10.22105/riej.2019.159539.1065

Abstract
  This paper deals with the number theoretic properties of non-unit elements of the ring Zn. Let D be the set of all non-trivial divisors of a positive integer n. Let D1 and D2 be the subsets of D having the least common multiple which are incongruent to zero modulo n with every other element of D ...  Read More