in this paper, an efficient extension of network simplex algorithm is presented. in static scheduling problem, where there is no change in situation, the challenge is that the large problems can be solved in a short time. in this paper, the static scheduling problem of automated guided vehicles in container terminal is solved by network simplex algorithm (nsa) and nsa+, which extended the stand...

in static scheduling problem, where there is no change in situation, the challenge is that the large problems can be solved in a short time. in this paper, the static scheduling problem of automated guided vehicles in container terminal is solved by the network simplex algorithm (nsa). the algorithm is based on graph model and their performances are at least 100 times faster than traditional si...

We present mixed integer programming approaches for optimally solving a combinatorial optimization problem arising in network design with additional quality of service constraints. The rooted delayand delay-variation-constrained Steiner tree problem asks for a cost-minimal Steiner tree satisfying delay-constraints from source to terminals and a maximal variation-bound between particular termina...

A single product maritime inventory routing problem is addressed in this paper by exploring the use of continuous and discrete time models. We first present a continuous time model based on time slots for single docks, which is enhanced by reformulating the time assignment constraints. Next, we present a model based on event points to handle parallel docks. A discrete time is also presented bas...

Supply chain management is taken into account as an inseparable component in satisfying customers' requirements. This paper deals with the distribution network design (DND) problem which is a critical issue in achieving supply chain accomplishments. A capable DND can guarantee the success of the entire network performance. However, there are many factors that can cause fluctuations in input dat...

The inter-domain Resource Exchange (iREX) architecture uses economic market mechanisms to automate the deployment of end to end (E2E) inter-domain (ID) quality of service (QoS) policy among resource consumer and resource provider Internet Service Providers (ISPs). Previous simulation results have shown that iREX allows more coexisting ID policy deployments with less network congestion when comp...

We present a new model for a strategic locomotive scheduling problem arising at the Deutsche Bahn AG. The model is based on a multi-commodity min-cost flow formulation that is also used for public bus scheduling problems. However, several new aspects have to be additionally taken into account, such as cyclic departures of the trains, time windows on starting and arrival times, network-load depe...

In this paper we consider the evolution of sets by a fractional mean curvature flow. Our main result states that for any dimension n > 2, there exists an embedded surface in R evolving by fractional mean curvature flow, which developes a singularity before it can shrink to a point. When n > 3 this result generalizes the analogue result of Grayson [18] for the classical mean curvature flow. Inte...

Classical network flow problems do not impose restrictions on the choice of paths on which flow is sent. Only the arc capacities of the network have to be obeyed. This scenario is not always realistic. In fact, there are many problems for which, e.g., the number of paths being used to route a commodity or the length of such paths has to be small. These restrictions are considered in the length-...