Showing 6 results for Fathi
P. Akhavan, M. Fathian, M. Jafari ,
Volume 18, Issue 3 (International Journal of Engineering 2007)
Abstract
Abstract: Nowadays knowledge is recognized as an important enabler for competitive advantages and many companies are beginning to establish knowledge management systems. Within the last few years many organizations tried to design a suitable knowledge management system and many of them were successful. This paper is to discover critical success factors (CSF) of knowledge management (KM) and their relationships in an effective way. A qualitative case study technique has been used in this paper for data collection and analysis. In this way, grounded theory (GT) research approach has been selected .The collected data are categorized and analyzed through specific stages of GT. A semantic network has been developed by categorized data showing the relationships between the extracted CSFs and finally a theory has been emerged. The semantic network and the emerged theory show the roadmap of success in KM area for the organizations.
J. Fathikalajahi, M. Baniadam , R. Rahimpour ,
Volume 19, Issue 3 (International Journal of Engineering 2008)
Abstract
An equation-oriented approach was developed for steady state flowsheeting of a commercial methanol plant. The loop consists of fixed bed reactor, flash separator, preheater, coolers, and compressor. For steady sate flowsheeting of the plant mathematical model of reactor and other units are needed. Reactor used in loop is a Lurgi type and its configuration is rather complex. Previously reactor and flash separator are modeled as two important units of plant. The model is based on mass and energy balances in each equipment and utilizing some auxiliary equations such as rate of reaction and thermodynamics model for activity coefficients of liquid. In order to validate the mathematical model for the synthesis loop, some simulation data were performed using operating conditions and characteristics of the commercial plant. The good agreement between the steady state simulation results and the plant data shows the validity of the model.
, , ,
Volume 20, Issue 1 (IJIEPR 2009)
Abstract
Fuzzy Cognitive Maps (FCMs) have successfully been applied in numerous domains to show the relations between essential components in complex systems. In this paper, a novel learning method is proposed to construct FCMs based on historical data and by using meta-heuristic: Genetic Algorithm (GA), Simulated Annealing (SA), and Tabu Search (TS). Implementation of the proposed method has demonstrated via real data of a purchase system in order to simulate the system’s behavior.
Masoud Narenji, Ahmad Makui, Mehdi Fathi ,
Volume 20, Issue 4 (IJIEPR 2010)
Abstract
Nowadays, interval comparison matrices (ICM) take an important role in decision making under uncertainty. So it seems that a brief review on solution methods used in ICM should be useful. In this paper, the common methods are divided into four categories that are Goal Programming Method (GPM), Linear Programming Method (LPM), Non-Linear Programming Method (NLPM) and Statistic Analysis (SA). GPM itself is divided also into three categories. This paper is a review paper and is written to introduce the mathematical methods and the most important applications of ICM in decision making techniques.
E. Teimoury, H. Ansari , M. Fathi ,
Volume 22, Issue 1 (IJIEPR 2011)
Abstract
The importance of reliable supply is increasing with supply chain network extension and just-in-time (JIT) production. Just in time implications motivate manufacturers towards single sourcing, which often involves problems with unreliable suppliers. If a single and reliable vendor is not available, manufacturer can split the order among the vendors in order to simultaneously decrease the supply chain uncertainty and increase supply reliability. In this paper we discuss with the aim of minimizing the shortage cost how we can split orders among suppliers with different lead times. The (s,S) policy is the basis of our inventory control system and for analyzing the system performance we use the fuzzy queuing methodology. After applying the model for the case study (SAPCO), the result of the developed model will be compared in the single and multiple cases and finally we will find that order splitting in optimized condition will conclude in the least supply risk and minimized shortage cost in comparison to other cases .
E. Teimoury, I.g. Khondabi , M. Fathi ,
Volume 22, Issue 3 (IJIEPR 2011)
Abstract
Discrete facility location, Distribution center, Logistics, Inventory policy, Queueing theory, Markov processes, |
The distribution center location problem is a crucial question for logistics decision makers. The optimization of these decisions needs careful attention to the fixed facility costs, inventory costs, transportation costs and customer responsiveness. In this paper we study the location selection of a distribution center which satisfies demands with a M/M/1 finite queueing system plus balking and reneging. The distribution center uses one for one inventory policy, where each arrival demand orders a unit of product to the distribution center and the distribution center refers this demand to its supplier. The matrix geometric method is applied to model the queueing system in order to obtain the steady-state probabilities and evaluate some performance measures. A cost model is developed to determine the best location for the distribution center and its optimal storage capacity and a numerical example is presented to determine the computability of the results derived in this study .
