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Full-Text Articles in Operations Research, Systems Engineering and Industrial Engineering

Senior Center Network Redesign Under Demand Uncertainty, Osman Ozaltin, Michael P. Johnson Jr., Andrew Schaefer Mar 2010

Senior Center Network Redesign Under Demand Uncertainty, Osman Ozaltin, Michael P. Johnson Jr., Andrew Schaefer

Michael P. Johnson

Senior centers off#11;er a variety of services to facilitate independent living of older adults. In the U.S., increasing suburbanization and aging of suburban residents necessitate reconfiguring senior services. We propose a two-echelon network of senior centers across large study areas and formulate a stochastic facility location/allocation model with mixed-integer recourse. We apply our model to Allegheny County, Pennsylvania, which has one of the oldest population in the U.S. Our model shows that a two-echelon network design is appropriate for increasing the occupancy of senior centers as community focal points while maintaining customized and accessible programming in small neighborhood areas.


Enacting Reliability: First Steps To Define Safety In The Vts Domain, Gesa Praetorius, Karl Bruno, Margareta Lützhöft Dec 2009

Enacting Reliability: First Steps To Define Safety In The Vts Domain, Gesa Praetorius, Karl Bruno, Margareta Lützhöft

Gesa Praetorius

Although the term maritime safety is widely used in the maritime industry, there is no exact definition of what it entails. An explorative study of the VTS domain has been conducted to approach the concept of maritime safety. Four VTS centres were visited and 16 VTS operators were interviewed and observed to derive insights in how maritime safety is constructed from the perspective of an operator. Further, definitions of maritime safety by central actors in the maritime domain have been investigated through a literature study and several interviews. The results indicate that there is no common definition of the term …