Erhan Kozan | QUT - Academia.edu (original) (raw)
Papers by Erhan Kozan
This data set includes information regarding a case study of a large Australian public hospital. ... more This data set includes information regarding a case study of a large Australian public hospital. This includes the size of the surgical department, details on surgical duration (assuming surgical duration is lognormally distributed), an initial waiting list, surgeon availability, and the average number of patients arriving per week.
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
Springer eBooks, Aug 3, 2007
Bookmarks Related papers MentionsView impact
Operations research for health care, Sep 1, 2016
Abstract In this paper we address the problem of generating master surgical schedules (MSSs) that... more Abstract In this paper we address the problem of generating master surgical schedules (MSSs) that adhere to staff and equipment restrictions whilst ensuring patients are treated in a timely manner. We simultaneously address the master surgical scheduling problem (MSSP) and the surgical case assignment problem (SCAP). Stochastic surgical durations are considered in order to produce more robust schedules and reduce unexpected overtime. Also incorporated into the model are several constraints regarding patient wait targets that are set by the Australian government. The problem is formulated using a mixed integer nonlinear programming (MINLP) approach and solved using a variety of hybrid metaheuristics. The metaheuristics implemented are inspired by simulated annealing (SA) and reduced variable neighbourhood search (RVNS). In particular, we present an adaptive SA and hybridise SA and RVNS to greatly improve solution quality. The solution neighbourhoods used by the metaheuristics are based on the hierarchical structure present in the combined MSSP SCAP. We consider a case study of an Australian public hospital with a large surgical department and compare the performance of our model to historical data.
Bookmarks Related papers MentionsView impact
Science & Engineering Faculty, 2017
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
International Journal of Production Research, Nov 25, 2015
This article contributes an original integrated model of an open-pit coal mine for supporting ene... more This article contributes an original integrated model of an open-pit coal mine for supporting energy-efficient decisions. Mixed integer linear programming is used to formulate a general integrated model of the operational energy consumption of four common open-pit coal mining subsystems: excavation and haulage, stockpiles, processing plants and belt conveyors. Mines are represented as connected instances of the four subsystems, in a flow sheet manner, which are then fitted to data provided by the mine operators. Solving the integrated model ensures the subsystems’ operations are synchronised and whole-of-mine energy efficiency is encouraged. An investigation on a case study of an open-pit coal mine is conducted to validate the proposed methodology. Opportunities are presented for using the model to aid energy-efficient decision-making at various levels of a mine, and future work to improve the approach is described.
Bookmarks Related papers MentionsView impact
arXiv (Cornell University), Aug 30, 2018
Bookmarks Related papers MentionsView impact
arXiv (Cornell University), Aug 30, 2018
Bookmarks Related papers MentionsView impact
Future Generation Computer Systems, Feb 1, 2017
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
arXiv (Cornell University), Aug 30, 2018
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
European Journal of Operational Research, 2016
Bookmarks Related papers MentionsView impact
IFAC Proceedings Volumes, 1995
Bookmarks Related papers MentionsView impact
Transportation Research Record, 1995
Scheduling of trains on a single line involves the use of train priorities for the resolution of ... more Scheduling of trains on a single line involves the use of train priorities for the resolution of conflicts. First, a mathematical programming model is described. The model schedules trains over a single line of track when the priority of each train in a conflict depends on an estimate of the remaining crossing and overtaking delay. This priority is used in a branch-and-bound procedure to allow the determination of optimal solutions quickly. This is demonstrated with the use of an example. Rail operations over a single-line track require the existence of a set of sidings at which trains can cross or overtake each other. Investment decisions on upgrading the numbers and locations of these sidings can have a significant impact on both customer service and rail profitability. Sidings located at insufficient positions may lead to high operating costs and congestion. Second, a model to determine the optimal position of a set of sidings on a single-track rail corridor is described. The sid...
Bookmarks Related papers MentionsView impact
Optimization Letters, May 14, 2016
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
Data in Brief, Dec 1, 2016
Bookmarks Related papers MentionsView impact
This data set includes information regarding a case study of a large Australian public hospital. ... more This data set includes information regarding a case study of a large Australian public hospital. This includes the size of the surgical department, details on surgical duration (assuming surgical duration is lognormally distributed), an initial waiting list, surgeon availability, and the average number of patients arriving per week.
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
Springer eBooks, Aug 3, 2007
Bookmarks Related papers MentionsView impact
Operations research for health care, Sep 1, 2016
Abstract In this paper we address the problem of generating master surgical schedules (MSSs) that... more Abstract In this paper we address the problem of generating master surgical schedules (MSSs) that adhere to staff and equipment restrictions whilst ensuring patients are treated in a timely manner. We simultaneously address the master surgical scheduling problem (MSSP) and the surgical case assignment problem (SCAP). Stochastic surgical durations are considered in order to produce more robust schedules and reduce unexpected overtime. Also incorporated into the model are several constraints regarding patient wait targets that are set by the Australian government. The problem is formulated using a mixed integer nonlinear programming (MINLP) approach and solved using a variety of hybrid metaheuristics. The metaheuristics implemented are inspired by simulated annealing (SA) and reduced variable neighbourhood search (RVNS). In particular, we present an adaptive SA and hybridise SA and RVNS to greatly improve solution quality. The solution neighbourhoods used by the metaheuristics are based on the hierarchical structure present in the combined MSSP SCAP. We consider a case study of an Australian public hospital with a large surgical department and compare the performance of our model to historical data.
Bookmarks Related papers MentionsView impact
Science & Engineering Faculty, 2017
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
International Journal of Production Research, Nov 25, 2015
This article contributes an original integrated model of an open-pit coal mine for supporting ene... more This article contributes an original integrated model of an open-pit coal mine for supporting energy-efficient decisions. Mixed integer linear programming is used to formulate a general integrated model of the operational energy consumption of four common open-pit coal mining subsystems: excavation and haulage, stockpiles, processing plants and belt conveyors. Mines are represented as connected instances of the four subsystems, in a flow sheet manner, which are then fitted to data provided by the mine operators. Solving the integrated model ensures the subsystems’ operations are synchronised and whole-of-mine energy efficiency is encouraged. An investigation on a case study of an open-pit coal mine is conducted to validate the proposed methodology. Opportunities are presented for using the model to aid energy-efficient decision-making at various levels of a mine, and future work to improve the approach is described.
Bookmarks Related papers MentionsView impact
arXiv (Cornell University), Aug 30, 2018
Bookmarks Related papers MentionsView impact
arXiv (Cornell University), Aug 30, 2018
Bookmarks Related papers MentionsView impact
Future Generation Computer Systems, Feb 1, 2017
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
arXiv (Cornell University), Aug 30, 2018
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
European Journal of Operational Research, 2016
Bookmarks Related papers MentionsView impact
IFAC Proceedings Volumes, 1995
Bookmarks Related papers MentionsView impact
Transportation Research Record, 1995
Scheduling of trains on a single line involves the use of train priorities for the resolution of ... more Scheduling of trains on a single line involves the use of train priorities for the resolution of conflicts. First, a mathematical programming model is described. The model schedules trains over a single line of track when the priority of each train in a conflict depends on an estimate of the remaining crossing and overtaking delay. This priority is used in a branch-and-bound procedure to allow the determination of optimal solutions quickly. This is demonstrated with the use of an example. Rail operations over a single-line track require the existence of a set of sidings at which trains can cross or overtake each other. Investment decisions on upgrading the numbers and locations of these sidings can have a significant impact on both customer service and rail profitability. Sidings located at insufficient positions may lead to high operating costs and congestion. Second, a model to determine the optimal position of a set of sidings on a single-track rail corridor is described. The sid...
Bookmarks Related papers MentionsView impact
Optimization Letters, May 14, 2016
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
Data in Brief, Dec 1, 2016
Bookmarks Related papers MentionsView impact