Showing 6 results for Nasiri
Zohreh Zahedian, Mohammad Mahdi Nasiri,
Volume 25, Issue 3 (IJIEPR 2014)
Abstract
In this paper, we develop a freight transportation model for railway network considering hazmat transportation issue. In the transportation system considered, different customers can request for carrying hazmat and non- hazmat boxes. It is assumed that the sequence of the trains in the network is known. The objective is assigning the non-hazmat boxes and hazmat boxes to wagons of the trains so that the transportation becomes safer. A zero-one integer programming model is presented that minimizes the cost of safe transportation. The model is solved using a new fuzzy approach.
Mohammad Mahdi Nasiri, Nafiseh Shamsi Gamchi, Seyed Ali Torabi,
Volume 27, Issue 4 (IJIEPR 2016)
Abstract
Hubs are critical elements of transportation networks. Location of hubs and allocation of demands to them are of high importance in the network design. The most important purpose of these models is to minimize the cost, but path reliability is also another important factor which can influence the location of hubs. In this paper, we propose a P-center hub location model with full interconnection among hubs while there are different paths between origins and destinations. The purpose of the model is to determine the reliable path with lower cost. Unlike the prior studies, the number of hubs in the path is not limited to two hubs. The presented model in this paper is bi-objective and includes cost and reliability to determine the best locations for hubs, allocation of the demands to hubs and the best path. In order to illustrate our model, a numerical example is presented and solved using the Cuckoo Optimization Algorithm.
Farzaneh Nasirian, Mohammad Ranjbar,
Volume 28, Issue 2 (IJIEPR 2017)
Abstract
Public transportation has been one of the most important research fields in the two last decades. The purpose of this paper is to create a schedule for public transport fleets such as buses and metro trains with the goal of minimizing the total transfer waiting time. We extend previous research works in the field of transit schedule with considering headways of each route as decision variables. In this paper, we formulate the problem as a mixed integer linear programming model and solve it using ILOG CPLEX solver. For large-scale test instances, we develop a metaheuristic based on the scatter search algorithm to obtain good solutions in a reasonable CPU run times. Finally, in the computational section, the efficiency of the proposed model and developed algorithm are compared with the existing results in the literature on a real railway network.
Mojtaba Hamid, Mahdi Hamid, Mohammad Mahdi Nasiri, Mahdi Ebrahimnia,
Volume 29, Issue 2 (IJIEPR 2018)
Abstract
Surgical theater is one of the most expensive hospital sources that a high percentage of hospital admissions are related to it. Therefore, efficient planning and scheduling of the operating rooms (ORs) is necessary to improve the efficiency of any healthcare system. Therefore, in this paper, the weekly OR planning and scheduling problem is addressed to minimize the waiting time of elective patients, overutilization and underutilization costs of ORs and the total completion time of surgeries. We take into account the available hours of ORs and the surgeons, legal constraints and job qualification of surgeons, and priority of patients in the model. A real-life example is provided to demonstrate the effectiveness and applicability of the model and is solved using ε-constraint method in GAMS software. Then, data envelopment analysis (DEA) is employed to obtain the best solution among the Pareto solutions obtained by ε-constraint method. Finally, the best Pareto solution is compared to the schedule used in the hospitals. The results indicate the best Pareto solution outperforms the schedule offered by the OR director.
Zohre Farmani, Gholamreza Nasiri, Gholamreza Zandesh,
Volume 34, Issue 3 (IJIEPR 2023)
Abstract
Today, the use of electrical energy storage has a significant role in flatting the load curve, peak shaving, increasing reliability and also increasing the penetration of distributed generation, reducing carbon emissions, and reducing network losses. In this article, a three-echelon power supply chain is investigated considering energy storage as a new level in the power supply chain. The model in this article is an integrated model of locating and capacity planning of distributed energy storage with the aim of maximizing profit and reliability, which is modeled with two different approaches. The first model is modeled from the point of view of the distribution network as the owner of the energy storage and the second model is modeled from the perspective of the electricity subscribers as the owner of the energy storage. Finally, the model is solved by GAMS software and the results of sensitivity analysis are presented. According to the obtained results, the presented model is the most sensitive to the changes in demand and production, and the owners of energy storage should be sensitive to the changes in production and demand in different seasons of the year in order to get the maximum profit.
Hamed Alizadeh, Ali Khavanin, Farahnaz Khajehnasiri, Niloofar Valizadeh, Ali Salehi Sahlabadi,
Volume 34, Issue 4 (IJIEPR 2023)
Abstract
Background: The lighting of the work environment and its quantitative and qualitative characteristics, such as the intensity of the light and the color temperature, as a physical characteristic, have a great impact on the mental health, behavior and performance of people. The physical factors of the work environment, the personality type and behavioral characteristics of people are effective in their efficiency and productivity. Methods: The current research is an interventional and laboratory research which was done in 2022, 35 male students of Tarbiat Modares University were studied. This study was designed in 3 locations with different lighting systems of LED lamps with color temperature of 3000, 4000 and 5000 degrees Kelvin. Stroop test software was used to check cognitive activities and Neo questionnaire was used to determine personality type. Results: The results showed that the average reaction time when facing the LED lamp with a color temperature of 4000 degrees Kelvin in the group of consonant words was the lowest (average response time 601.22 milliseconds) and at a color temperature of 3000 degrees Kelvin in the group of dissonant words the highest value (average 88. 645 milliseconds). The average number of errors in the group of dissonant words was the highest when faced with a color temperature of 3000 degrees Kelvin (the average number of errors was 10.8), the lowest amount of errors was observed in the group of consonant words at a color temperature of 5000 degrees Kelvin (the average number of errors was 2.71 ). Also, according to the obtained results and checking the interference score of the people, which shows the level of their selective attention, it was found that the average interference score at the color temperature of 3000 degrees Kelvin is the highest (average 6.05) and when faced with the color temperature of 4000 degrees Kelvin The lowest value was (average 4.14). The results of investigating the relationship between cognitive activities and the personality type of the subjects studied at different color temperatures showed that there was a negative and significant correlation between the interference score of the personality type of the subjects at a temperature of 3000 degrees Kelvin (P value = 0.33). Also, by examining this relationship at a color temperature of 5000 degrees Kelvin, it was found that there is a negative and significant correlation between the interference score and the interference time (another parameter affecting selective attention) with the personality type of people (P value = 0.42 and 0.38, respectively). = P value) Conclusions: The results of this study showed that the LED lighting system with high color temperature can be effective on people's cognitive performance by reducing errors and increasing attention and reaction time. In order to improve people's cognitive performance, it is suggested to use lighting system with high color temperature in sensitive places.
