Research Paper
Engineering Optimization
Parviz Tohidi Nasab; Mohsen Vaez Ghasemi; Ghasem Tohidi
Abstract
The Aircraft Scheduling Problem (ASP) refers to allocating each aircraft to the optimal take-off and landing time and the appropriate runway. This problem is the allocation of aircraft to the desired runway so that the total damage due to delays or haste in landing or take-off of all aircraft is minimized. ...
Read More
The Aircraft Scheduling Problem (ASP) refers to allocating each aircraft to the optimal take-off and landing time and the appropriate runway. This problem is the allocation of aircraft to the desired runway so that the total damage due to delays or haste in landing or take-off of all aircraft is minimized. Runway allocation, landing and take-off sequences, and scheduling for each aircraft must be done in a predetermined time window. Time should also be considered as the time of separation between landings and take-offs due to the wake vortex phenomenon. In general, the purpose of such problems is to make maximum use of the runway. Therefore, in this study, a mathematical model of robust landing and take-off scheduling at an airport is provided, assuming no access to the airport runway at certain times. Moreover, delays and haste in landing and take-off on the runway, limited access to aircraft, runway repair time, and the possibility of runway disturbances are investigated. Robust optimization is used to deal with uncertainty at take-off and landing times. Finally, Genetic and Imperialistic Competitive Algorithm are used to evaluate and analyze the problem because it is NP-HARD problem. The results indicate the ability of the proposed algorithms to find high-quality solutions in a short computation time for problems up to 7 runways and 60 aircraft.
Research Paper
Engineering Optimization
Mohammad Hossein Sattarkhan
Abstract
A multi-product system is one of the different types of manufacturing systems, in which a large number of products are produced that complement each other and have interdependence. These types of systems have recently been widely used in various industries. In some types of multi-product manufacturing ...
Read More
A multi-product system is one of the different types of manufacturing systems, in which a large number of products are produced that complement each other and have interdependence. These types of systems have recently been widely used in various industries. In some types of multi-product manufacturing industries that offer their products as a package, the scheduling of the production of components of each package affects the time it takes to complete the package. Therefore, a new problem has been defined that the primary purpose of its production scheduling, in addition to reducing the completion time of the products, is to make various items forming a package, get ready over a short interval of time and be supplied to the sales unit so that the package can be delivered to the final consumer. The purpose of this paper is to express the problem of production scheduling of multi-product production systems in the form of linear programming. For this purpose, two mathematical models are presented, and their functions are compared. Besides, an efficient genetic algorithm is proposed to solve the problem, which is able to solve the problem in a reasonable time, with acceptable accuracy.
Research Paper
Case studies in industry and services
ALI EHSANI; HASSAN MEHRMANESH; Mahmoud Mohammadi
Abstract
This study aims to identify and prioritize the effect of technology capability drivers on the supply chain performance of automotive companies. Technology capability indicators are ranked and prioritized using the fuzzy hierarchical analysis technique. The research method is applied in terms of purpose, ...
Read More
This study aims to identify and prioritize the effect of technology capability drivers on the supply chain performance of automotive companies. Technology capability indicators are ranked and prioritized using the fuzzy hierarchical analysis technique. The research method is applied in terms of purpose, is described as the data collection method, and is considered quantitative research. After reviewing the theoretical literature of the research, the drivers of technology capability on the organization's performance were identified for prioritization; they were weighed by a number of experts in the field of automotive companies using questionnaires and fuzzy hierarchical analysis. Indicators and sub-indices of variable technology capability were ranked and prioritized. Based on the results of this research model, it was found that of the eight indicators examined, "strategic technology capability", "product technology capability", and "supplier technology" was the most important, and of the 38 technology capability sub-indicators examined, "Technology Development" is the most important.
Research Paper
Supply chain management
Sirous Balaei; Nabiollah Mohammadi; Homa Doroudi
Abstract
Due to the importance of environmental effects of manufacturing system in recent decades, the production systems are obliged to comply different environmental regulations. The present research, aims to design a green supply chain model for Guilan steel industry with a hybrid approach. This study is applied ...
Read More
Due to the importance of environmental effects of manufacturing system in recent decades, the production systems are obliged to comply different environmental regulations. The present research, aims to design a green supply chain model for Guilan steel industry with a hybrid approach. This study is applied research in term of purpose, exploratory in term of method, quantitative and qualitative in terms of data type. A researcher made questionnaire are applied, in addition to interview, for data gathering. The under-study research population includes steel industry experts out of them, 12 experts were selected for data gathering phase. Conducting the research, first applying fuzzy Delphi method, 5 main factors and 25 important sub-factors were identified. Then, using fuzzy DEMATEL and interpretive structural modeling (ISM) methods, the importance of each facto was determined, in which two factors "external environment study" and "internal environment study" were at the highest level of the importance, while "Waste reduction", "waste recycling" and "purchasing based on environmental products" were at the last level. These variables are interrelated and affect their next levels.
