23 research outputs found

    A multi objective volleyball premier league algorithm for green scheduling identical parallel machines with splitting jobs

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    Parallel machine scheduling is one of the most common studied problems in recent years, however, this classic optimization problem has to achieve two conflicting objectives, i.e. minimizing the total tardiness and minimizing the total wastes, if the scheduling is done in the context of plastic injection industry where jobs are splitting and molds are important constraints. This paper proposes a mathematical model for scheduling parallel machines with splitting jobs and resource constraints. Two minimization objectives - the total tardiness and the number of waste - are considered, simultaneously. The obtained model is a bi-objective integer linear programming model that is shown to be of NP-hard class optimization problems. In this paper, a novel Multi-Objective Volleyball Premier League (MOVPL) algorithm is presented for solving the aforementioned problem. This algorithm uses the crowding distance concept used in NSGA-II as an extension of the Volleyball Premier League (VPL) that we recently introduced. Furthermore, the results are compared with six multi-objective metaheuristic algorithms of MOPSO, NSGA-II, MOGWO, MOALO, MOEA/D, and SPEA2. Using five standard metrics and ten test problems, the performance of the Pareto-based algorithms was investigated. The results demonstrate that in general, the proposed algorithm has supremacy than the other four algorithms

    A multi objective volleyball premier league algorithm for green scheduling identical parallel machines with splitting jobs

    Get PDF
    Parallel machine scheduling is one of the most common studied problems in recent years, however, this classic optimization problem has to achieve two conflicting objectives, i.e. minimizing the total tardiness and minimizing the total wastes, if the scheduling is done in the context of plastic injection industry where jobs are splitting and molds are important constraints. This paper proposes a mathematical model for scheduling parallel machines with splitting jobs and resource constraints. Two minimization objectives - the total tardiness and the number of waste - are considered, simultaneously. The obtained model is a bi-objective integer linear programming model that is shown to be of NP-hard class optimization problems. In this paper, a novel Multi-Objective Volleyball Premier League (MOVPL) algorithm is presented for solving the aforementioned problem. This algorithm uses the crowding distance concept used in NSGA-II as an extension of the Volleyball Premier League (VPL) that we recently introduced. Furthermore, the results are compared with six multi-objective metaheuristic algorithms of MOPSO, NSGA-II, MOGWO, MOALO, MOEA/D, and SPEA2. Using five standard metrics and ten test problems, the performance of the Pareto-based algorithms was investigated. The results demonstrate that in general, the proposed algorithm has supremacy than the other four algorithms

    Multi-objective volleyball premier league algorithm

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    This paper proposes a novel optimization algorithm called the Multi-Objective Volleyball Premier League (MOVPL) algorithm for solving global optimization problems with multiple objective functions. The algorithm is inspired by the teams competing in a volleyball premier league. The strong point of this study lies in extending the multi-objective version of the Volleyball Premier League algorithm (VPL), which is recently used in such scientific researches, with incorporating the well-known approaches including archive set and leader selection strategy to obtain optimal solutions for a given problem with multiple contradicted objectives. To analyze the performance of the algorithm, ten multi-objective benchmark problems with complex objectives are solved and compared with two well-known multiobjective algorithms, namely Multi-Objective Particle Swarm Optimization (MOPSO) and Multi-Objective Evolutionary Algorithm Based on Decomposition (MOEA/D). Computational experiments highlight that the MOVPL outperforms the two state-of-the-art algorithms on multi-objective benchmark problems. In addition, the MOVPL algorithm has provided promising results on well-known engineering design optimization problems

    Predicting the necessity of oxygen therapy in the early stage of COVID-19 using machine learning

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    Medical oxygen is a critical element in the treatment process of COVID-19 patients which its shortage impacts the treatment process adversely. This study aims to apply machine learning (ML) to predict the requirement for oxygen-based treatment for hospitalized COVID-19 patients. In the first phase, demographic information, symptoms, and patient鈥檚 background were extracted from the databases of two local hospitals in Iran, and preprocessing actions were applied. In the second step, the related features were selected. Lastly, five ML models including logistic regression (LR), random forest (RF), XGBoost, C5.0, and neural networks (NNs) were implemented and compared based on their accuracy and capability. Among the vari- ables related to the patient鈥檚 background, consuming opium due to the high rate of opium users in Iran was considered in the models. Of the 398 patients included in the study, 112 (28.14%) received oxygen-based treatment. Shortness of breath (71.42%), fever (62.5%), and cough (59.82%) had the highest frequency in patients with oxygen requirements. The most important variables for prediction were shortness of breath, cough, age, and fever. For opioid-addicted patients, in addition to the high mortality rate (23.07%), the rate of oxygen-based treatment was twice as high as non-addicted patients. XGBoost and LR obtained the highest area under the curve with values of 88.7% and 88.3%, respectively. For accuracy, LR and NNs achieved the best and same accuracy (86.42%). This approach provides a tool that accurately predicts the need for oxygen in the treatment process of COVID-19 patients and helps hospital resource management. Keywords COVID-19 路 Opioid addiction 路 Oxygen treatment 路 Prediction 路 Machine learning 路 XGBoos

    Modelling and performance evaluation of workflows using timed hierarchical Petri nets

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    A Decision Support System for University Course Timetabling: Persian Gulf University Case Study

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    University course timetabling problem is a serious challenge for the academic managers in each semester. Because of a vast number of constraints and the complexity of relationship among the constraints, the problem is known to be of hard class. In this paper, a decision support system is proposed to assist the decision makers in solving the university course timetabling. The proposed system produces a feasible and satisfactory solution. The system consists of four sub-systems (1) a database, (2) a dialogue component, (3) a process component, and (4) an optimization component. In order to implement the decision support system, the required software package is developed in C# and Microsoft Access database management system is also used. The optimization component utilizes graph coloring heuristics to solve the problem. The approach of the research is field study. The proposed decision support system has been applied to the faculty of humanities at the Persian Gulf University of Bushehr. Compared to the current methods, the results have shown that the proposed system has a better performance in terms of satisfying constraints, and saving time and money

    A Framework for Analysis of Inter-organizational Factors Affecting on the Security of Information Systems using FAHP Approach

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    Security of information systems as a new area of information technology is of a great importance in creating confidence and growth in the use of information systems. Although in recent years many researchers and IT experts have focused on the technical aspects of security, but less attention has been paid to its organizational and managerial aspects. To investigate the factors affecting on the creating and maintaining of security of information systems, this study identifies the inter-organizational factors. Then, by designing a questionnaire and using Fuzzy Analytic Hierarchical Process (FAHP) technique, the weights and ranks of factors are calculated. The results show that human factor is the most important inter-organizational factor that influences information systems security. Also, the lack of information about the value and importance of information is identified as the most important sub factor
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