The Experts below are selected from a list of 300 Experts worldwide ranked by ideXlab platform
Yifan Zhou - One of the best experts on this subject based on the ideXlab platform.
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Maintenance optimisation of a parallel-series system with stochastic and Economic Dependence under limited maintenance capacity
Reliability Engineering & System Safety, 2016Co-Authors: Yifan Zhou, Tian Ran Lin, Yong SunAbstract:Maintenance optimisation of a parallel-series system considering both stochastic and Economic Dependence among components as well as limited maintenance capacity is studied in this paper. The maintenance strategies of the components are jointly optimised, and the degradation process of the system is modelled to address the stochastic Dependence and limited maintenance capacity issues. To overcome the “curse of dimensionality” problem where the state space of a parallel-series system increases rapidly with the increased number of components in the system, the factored Markov decision process (FMDP) is employed for maintenance optimisation in this work. An improved approximate linear programming (ALP) algorithm is then developed. The selection of the basis functions and the state relevance weights for ALP is also investigated to enhance the performance of the ALP algorithm. Results from the numerical study show that the current approach can handle the decision optimisation problem for multi-component systems of moderate size, and the error of maintenance decision-making induced by the improved ALP is negligible. The outcome from this research provides a useful reference to overcome the “curse of dimensionality” problem during the maintenance optimisation of multi-component systems.
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Maintenance optimisation of a multi-state series-parallel system considering Economic Dependence and state-dependent inspection intervals
Reliability Engineering & System Safety, 2013Co-Authors: Yifan Zhou, Zhisheng Zhang, Tian Ran LinAbstract:This paper presents a maintenance optimisation method for a multi-state series-parallel system considering Economic Dependence and state-dependent inspection intervals. The objective function considered in the paper is the average revenue per unit time calculated based on the semi-regenerative theory and the universal generating function (UGF). A new algorithm using the stochastic ordering is also developed in this paper to reduce the search space of maintenance strategies and to enhance the efficiency of optimisation algorithms. A numerical simulation is presented in the study to evaluate the efficiency of the proposed maintenance strategy and optimisation algorithms. The simulation result reveals that maintenance strategies with opportunistic maintenance and state-dependent inspection intervals are more cost-effective when the influence of Economic Dependence and inspection cost is significant. The study further demonstrates that the optimisation algorithm proposed in this paper has higher computational efficiency than the commonly employed heuristic algorithms.
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Maintenance optimisation of a series-parallel system with multi-state components considering Economic Dependence
2012 International Conference on Quality Reliability Risk Maintenance and Safety Engineering, 2012Co-Authors: Yifan Zhou, Zhisheng ZhangAbstract:The maintenance optimisation of a series-parallel system is a practical and imperative research topic. However, existing research on the maintenance of a series-parallel system largely ignores the Economic Dependence among components, which can increase the maintenance cost. In addition, most current research assumes that the components in a system only have two states, while condition monitoring techniques can often provide more detailed health information of components. This paper proposes a maintenance optimisation method for a series-parallel system with multistate components considering Economic Dependence. The state of a subsystem is defined based on both the combination of component states and current maintenance actions. Using the results of the steady-state analysis of subsystem states, the average revenue per unit time of the system is calculated as the objective function of maintenance optimisation. The optimal strategy is then identified by the enumerative method. A simulation study is conducted to investigate the performance of the proposed maintenance optimisation method. The results show that the proposed method can identify the optimal maintenance strategy efficiently, and the maintenance strategy considering the Economic Dependence can enhance the revenue significantly.
Mayank Kumar Pandey - One of the best experts on this subject based on the ideXlab platform.
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selective maintenance for multi state series parallel systems under Economic Dependence
Reliability Engineering & System Safety, 2014Co-Authors: Cuong D Dao, Ming J Zuo, Mayank Kumar PandeyAbstract:Abstract This paper presents a study on selective maintenance for multi-state series–parallel systems with Economically dependent components. In the selective maintenance problem, the maintenance manager has to decide which components should receive maintenance activities within a finite break between missions. All the system reliabilities in the next operating mission, the available budget and the maintenance time for each component from its current state to a higher state are taken into account in the optimization models. In addition, the components in series–parallel systems are considered to be Economically dependent. Time and cost savings will be achieved when several components are simultaneously repaired in a selective maintenance strategy. As the number of repaired components increases, the saved time and cost will also increase due to the share of setting up between components and another additional reduction amount resulting from the repair of multiple identical components. Different optimization models are derived to find the best maintenance strategy for multi-state series–parallel systems. A genetic algorithm is used to solve the optimization models. The decision makers may select different components to be repaired to different working states based on the maintenance objective, resource availabilities and how dependent the repair time and cost of each component are.
David L. Imbroscio - One of the best experts on this subject based on the ideXlab platform.
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OVERCOMING THE Economic Dependence OF URBAN AMERICA: A Review of Strategies
Journal of Urban Affairs, 1993Co-Authors: David L. ImbroscioAbstract:: From apolitical economy perspective, US cities are compelled to attract and retain Economic resources, especially capital. Most scholars agree that urban Economic Dependence works to bias local politics. This paper reviews strategies to mitigate urban Economic Dependence.
Tian Ran Lin - One of the best experts on this subject based on the ideXlab platform.
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Maintenance optimisation of a parallel-series system with stochastic and Economic Dependence under limited maintenance capacity
Reliability Engineering & System Safety, 2016Co-Authors: Yifan Zhou, Tian Ran Lin, Yong SunAbstract:Maintenance optimisation of a parallel-series system considering both stochastic and Economic Dependence among components as well as limited maintenance capacity is studied in this paper. The maintenance strategies of the components are jointly optimised, and the degradation process of the system is modelled to address the stochastic Dependence and limited maintenance capacity issues. To overcome the “curse of dimensionality” problem where the state space of a parallel-series system increases rapidly with the increased number of components in the system, the factored Markov decision process (FMDP) is employed for maintenance optimisation in this work. An improved approximate linear programming (ALP) algorithm is then developed. The selection of the basis functions and the state relevance weights for ALP is also investigated to enhance the performance of the ALP algorithm. Results from the numerical study show that the current approach can handle the decision optimisation problem for multi-component systems of moderate size, and the error of maintenance decision-making induced by the improved ALP is negligible. The outcome from this research provides a useful reference to overcome the “curse of dimensionality” problem during the maintenance optimisation of multi-component systems.
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Maintenance optimisation of a multi-state series-parallel system considering Economic Dependence and state-dependent inspection intervals
Reliability Engineering & System Safety, 2013Co-Authors: Yifan Zhou, Zhisheng Zhang, Tian Ran LinAbstract:This paper presents a maintenance optimisation method for a multi-state series-parallel system considering Economic Dependence and state-dependent inspection intervals. The objective function considered in the paper is the average revenue per unit time calculated based on the semi-regenerative theory and the universal generating function (UGF). A new algorithm using the stochastic ordering is also developed in this paper to reduce the search space of maintenance strategies and to enhance the efficiency of optimisation algorithms. A numerical simulation is presented in the study to evaluate the efficiency of the proposed maintenance strategy and optimisation algorithms. The simulation result reveals that maintenance strategies with opportunistic maintenance and state-dependent inspection intervals are more cost-effective when the influence of Economic Dependence and inspection cost is significant. The study further demonstrates that the optimisation algorithm proposed in this paper has higher computational efficiency than the commonly employed heuristic algorithms.
Na Wang - One of the best experts on this subject based on the ideXlab platform.
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selective maintenance problem for series parallel system under Economic Dependence
Defence Technology, 2016Co-Authors: Lemeng Guo, He-ping Shi, Na WangAbstract:Abstract In view of the high complexity of the objective world, an Economic Dependence between subsystems (paired and unpaired) is proposed, and then the maintenance cost and time under different Economic Dependences are formulated in a simple and consistent manner. Selective maintenance problem under Economic Dependence (EDSMP) is presented based on a series–parallel system in this paper. A case study shows that the system reliability is promoted to a certain extent, which can validate the validity of the EDSMP model. The influence of the ratio of set-up cost on system performance is mainly discussed under different Economic Dependences. Several existing improvements of classical exhaust algorithm are further modified to solve a large sized EDSMP rapidly. Experimental results illustrate that these improvements can reduce CPU time significantly. Furthermore the contribution of each improvement is defined here, and then their contributions are compared thoroughly.
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Selective maintenance model for multi-state system under Economic Dependence
2016 Chinese Control and Decision Conference (CCDC), 2016Co-Authors: Lemeng Guo, Na WangAbstract:In selective maintenance problem, maintenance decision-makers have to identify a subset of activities to perform among all feasible maintenance actions due to limitations on maintenance resources. Selective maintenance model for multi-state series-parallel system under Economic Dependence is proposed in this paper. The series-parallel system and its components have several finite levels of performance. Maintenance cost and time for repairing each component are discussed under different types of Economic Dependence. The optimization problem is solved by evolutionary algorithm, and an illustrative example is then presented. Selective maintenances under different types of Economic Dependence are compared, and their sensitivities of maintenance resources are also analyzed.
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Selective maintenance problem for series–parallel system under Economic Dependence
Defence Technology, 2016Co-Authors: Lemeng Guo, He-ping Shi, Na WangAbstract:Abstract In view of the high complexity of the objective world, an Economic Dependence between subsystems (paired and unpaired) is proposed, and then the maintenance cost and time under different Economic Dependences are formulated in a simple and consistent manner. Selective maintenance problem under Economic Dependence (EDSMP) is presented based on a series–parallel system in this paper. A case study shows that the system reliability is promoted to a certain extent, which can validate the validity of the EDSMP model. The influence of the ratio of set-up cost on system performance is mainly discussed under different Economic Dependences. Several existing improvements of classical exhaust algorithm are further modified to solve a large sized EDSMP rapidly. Experimental results illustrate that these improvements can reduce CPU time significantly. Furthermore the contribution of each improvement is defined here, and then their contributions are compared thoroughly.
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Selective maintenance model and its solution algorithm for multi-state series-parallel system under Economic Dependence
2016 Chinese Control and Decision Conference (CCDC), 2016Co-Authors: Lemeng Guo, Na WangAbstract:Selective maintenance model for multi-state series-parallel system under Economic Dependence is proposed in this paper. The series-parallel system and its components have several finite levels of performance, and its reliability evaluation is performed by Universal Generating Function approach. The optimization problem is solved by Differential Evolution (DE) algorithm, and an illustrative example is then presented. Selective maintenances under different maintenance policies and system demands are analyzed to evaluate their contribution to system reliability, and five DE algorithms are also compared to determine the most suitable one.
