Set multi-covering is a generalization of the set covering problem where each element may need to be covered more than once and thus some subset in the given family of subsets may be picked several times for minimizing the number of sets to satisfy the coverage requirement. In this paper, we propose a family of exact algorithms for the set multi-covering problem based on the inclusionexclusion ...

Unexpected disruptions occur for many reasons in railway networks and cause delays, cancellations, and, eventually, passenger inconvenience. This research focuses on the railway timetable rescheduling problem from a macroscopic point of view in case of large disruptions. The originality of our approach is to integrate three objectives to generate a disposition timetable: the passenger satisfact...

Algorithmic mechanism design deals with efficiently-computable algorithmic constructions in the presence of strategic players who hold the inputs to the problem and may misreport their input if doing so benefits them. Algorithmic mechanism design finds applications in a variety of internet settings such as resource allocation, facility location and e-commerce, such as sponsored search auctions....

1 Sub-Problems and Objectives Divide and conquer techniques in problem solving are familiar and intuitive; first find the solution to sub-problems and then re-use these to find solutions to the whole problem. For example, we may decompose the problem of designing a vehicle into designing the engine and designing the body. It is acknowledged that most real-world problems (vehicles included) do n...

In this paper, a new approach to risk minimizing vehicle routing and scheduling problem is presented. Forwarding agents or companies have two main concerns for the collection of high-risk commodities like cash or valuable commodities between the central depot and the customers: one; because of the high value of the commodities transported, the risk of ambush and robbery are very high. Two; the ...

In this paper, a model is presented to locate ambulances, considering backup facility (to increase reliability) and the restriction of ambulance capacity. This model is designed for emergencies. In this model the covered demand for each demand point depends on the number of coverage times and the amount of demand. The demand amount and ambulance coverage radius are considered...

Green hydrogen is addressed as a promising solution to decarbonize industrial and mobility sectors. In this context, ports could play key role not only users but also suppliers for plants with which they have strong commercial ties. The implementation of technologies in has started be strategy renewable energy transition still requires detailed evaluation the involved costs, cannot separated fr...

This study proposes a new multi-item inventory model with hybrid cost parameters under a fuzzy-stochastic constraint and permissible delay in payment. The price and marketing expenditure dependent stochastic demand and the demand dependent the unit production cost are considered. Shortages are allowed and partially backordered. The main objective of this paper is to determine selling price, mar...

This paper introduces a special kind of multi-depot pickup and delivery problem. In contrast to the general pickup and delivery problem (GPDP, see e.g. [19, 31]) all requests have to be picked up at or delivered to one central location which has the function of a hub or consolidation point. In hub transportation networks routes between customers and the hub are often short, i.e. involve only on...