We consider a pairwise kidney exchange model. Roth et al. (2005) define priority matchings of the model and introduce a mechanism to derive them. In this paper, we re-examine the priority matching. First, we consider a general priority ordering where multiple patients may hold equal priority. We...

This paper considers the uncapacitated lot sizing problem with batch delivery, focusing on the general case of time-dependent batch sizes. We study the complexity of the problem, depending on the other cost parameters, namely the setup cost, the fixed cost per batch, the unit procurement cost...

The x-and-y-axes travelling salesman problem forms a special case of the Euclidean TSP, where all cities are situated on the x-axis and on the y-axis of an orthogonal coordinate system of the Euclidean plane. By carefully analyzing the underlying combinatorial and geometric structures, we show...