Showing 5 results for Said
I. Mahdavi, M. M. Paydar, M. Solimanpur , M. Saidi-Mehrabad,
Volume 21, Issue 2 (IJIEPR 2010)
Abstract
This paper deals with the cellular manufacturing system (CMS) that is based on group technology concepts. CMS is defined as identifying the similar parts that are processed on the same machines and then grouping them as a cell. The most proposed models for solving CMS are focused on cell formation problem while machine layout is considered in few papers. This paper addresses a mathematical model for the joint problem of the cell formation problem and the machine layout. The objective is to minimize the total cost of inter-cell and intra-cell (forward and backward) movements and the investment cost of machines. This model has also considered the minimum utilization level of each cell to achieve the higher performance of cell utilization. Two examples from the literature are solved by the LINGO Software to validate and verify the proposed model.
Kamyar Sabri Laghaie, Mohammad Saidi Mehrabad, Arash Motaghedi Larijani,
Volume 22, Issue 4 (IJIEPR 2011)
Abstract
In this paper a single server queuing production system is considered which is subject to gradual deterioration. The system is discussed under two different deteriorating conditions. A planning horizon is considered and server which is a D/M/1 queuing system is gradually deteriorates through time periods. A maintenance policy is taken into account whereby the server is restored to its initial condition before some distinct periods. This system is modeled to obtain optimal values of arrival rates and also optimal maintenance policy which minimizes production, holding and maintenance costs and tries to satisfy demands through time periods. The model is also considered to control customers’ sojourn times. For each deteriorating condition a model is developed. Models are solved by GA based algorithms and results for a sample are represented .
Bahman Esmailnezhad, Mohammad Saidi-Mehrabad,
Volume 29, Issue 1 (IJIEPR 2018)
Abstract
This paper deals the stochastic cell formation problem (SCFP). The paper presents a new nonlinear integer programming model for the SCFP in which the effect of buffer size on the grouping efficacy of cells has been investigated. The objective function is the maximization of the grouping efficacy of cells. A chance constraint is applied to explore the effect of buffer on the SCFP. Processing time and arrival time of the part for each cell are considered stochastic and are following exponential probability distribution. To find out the optimal solution in a reasonable time, a heuristic approach is used to linearize the proposed nonlinear model. This problem has been known as an NP-hard problem. Therefore, two metaheuristic methods, namely; genetic algorithm and particle swarm optimization are employed to solve examples. The parameters of the algorithms are calibrated using Taguchi and full factorial methods, and the performances of the algorithms on the examples of various sizes are analyzed against global solutions obtained from Lingo software’s branch and bound (B&B) in terms of quality of solutions and computational time.
Fatemeh Elhambakhsh, Mohammad Saidi- Mehrabad,
Volume 32, Issue 1 (IJIEPR 2021)
Abstract
Statistical monitoring of dynamic networks is a major topic of interest in complex social systems. Many researches have been conducted on modeling and monitoring dynamic social networks. This article proposes a new methodology for modeling and monitoring dynamic social networks for quick detection of temporal anomalies in network structures using latent variables. The key idea behind our proposed methodology is to determine the importance of latent variables in creating edges between nodes as well as observed covariates. First, latent space model (LSM) is used to model dynamic networks. Vector of parameters in LSM model are monitored through multivariate control charts in order to detect changes in different network sizes. Experiments on simulated social network monitoring demonstrate that our surveillance monitoring strategy can effectively detect abrupt changes between actors in dynamic networks using latent variables.
Laila Refiana Said, Zainal Arifin, Meldasari Said,
Volume 34, Issue 2 (IJIEPR 2023)
Abstract
Numerous studies have examined the increasing number of virtual team communication usage, especially during the Covid-19 pandemic. However, little research has been conducted on the factors affecting its effectiveness in improving task performance, seeing the virtual team's rapid development today. Therefore, this study examines the effect of direct and indirect employee preferences and organizational support on task performance through virtual teamwork communication. The research method used was a survey of 156 employees in the fields of education, telecommunications, transportation, and health in Banjarmasin city, who work from home, interact with colleagues who also work from home, and with colleagues who work in the office. The analysis was carried out using path analysis. The results showed that employee preferences and organizational support directly affected task performance. Virtual team communication can mediate the influence of employee preferences and organizational support on task performance. The research implies that virtual team communication that runs well can improve work performance. Therefore, it requires collaborative support, both from individuals and the organization.
