Assessing the queuing process using data envelopment analysis:an application in health centres

Queuing is one of the very important criteria for assessing the performance and efficiency of any service industry, including healthcare. Data Envelopment Analysis (DEA) is one of the most widely-used techniques for performance measurement in healthcare. However, no queue management application has been reported in the health-related DEA literature. Most of the studies regarding patient flow systems had the objective of improving an already existing Appointment System. The current study presents a novel application of DEA for assessing the queuing process at an Outpatients’ department of a large public hospital in a developing country where appointment systems do not exist. The main aim of the current study is to demonstrate the usefulness of DEA modelling in the evaluation of a queue system. The patient flow pathway considered for this study consists of two stages; consultation with a doctor and pharmacy. The DEA results indicated that waiting times and other related queuing variables included need considerable minimisation at both stages

Analysis of the resistance variation of the thermoconverters sensitive elements and method of corrosion type definition in aggressive environments

W przedstawionym materiale rozwijane są metody określania rodzaju korozji materiałów termoprzetworników rezystancyjnych w środowiskach agresywnych. Również przeanalizowano wpływ korozji na zmiany statycznych charakterystyk przetwarzania badanych termoprzetworników. Zaproponowano stosowanie dwóch podstawowych modeli korozji: jednolitej i wżerowej.This article represents the development of corrosion type definition of the resistance thermoconverters materials in aggressive environment. Also, the corrosion impact to the variation of the investigated thermoconverters static characteristics is analysed. Two major methods of corrosion are proposed: pitting and uniform. The performed investigation results show that, it is possible suggest about corrosion type, based on the behavior of the sensitive element resistance variation caused by corrosion. The uniform corrosion dominates in case of linear time-dependence of sensitive element resistance. There is high probability of pitting corrosion if the non-linearity of sensitive element resistance is observed

Grid-enabled evolution strategies for large-scale home care crew scheduling

The home care crew scheduling (HCCS) problem is a planning task whose goal is to allocate a set of professional caregivers in the most efficient way to perform a number of assistencial and health care visits to the customers private homes. This is part of an important trend in advanced health care systems, to promote "independent living" specially in situations of dependency on long-term care. This not only ensures a higher quality of life but also a lower cost for society. Real instances of the HCCS problem are large and highly constrained due to both caregivers' contract limitations and customers' needs. This paper presents an advanced parallel model that solves HCCS problems using a grid-based asynchronous evolutionary algorithm (EA). Our approach has been tested using a grid computing facility of up to 300 nodes. The algorithm is a modified (1 + lambda) EA, parallelized using a master/worker model that minimizes communication requirements and processor bottlenecks by distributing both the execution of the EA operators and the evaluation of solutions. We have used three large real-world instances provided by a private company to perform experimentation with different configurations of the EA and number of workers. Results show that our algorithm achieves solutions that clearly outperform the solution provided by the company and the grid-based algorithm is able to handle real world HCCS problemsThe work of Francisco Luna and Juan F. Valenzuela is funded by the Spanish Ministry of Economy, Industry and Competitiveness under contract TIN2016-75097-P. The work of Alejandro Cervantes and Pedro Isasi is funded by the Spanish Ministry of Science and Innovation under contract TIN2011-28336