Ruben van der Zwaan

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We consider the Vector Scheduling problem, a natural generalization of the classical makespan minimization problem to multiple resources. Here, we are given n jobs, represented as d-dimensional vectors in $$[0,1]^d$$ [ 0 , 1 ] d , and m identical machines, and the goal is to assign the jobs to machines such that the maximum load of each machine over all the(More)
The Border Gateway Protocol (BGP) serves as the main routing protocol of the Internet and ensures network reachability among autonomous systems (ASes). When traffic is forwarded between the many ASes on the Internet according to that protocol, each AS selfishly routes the traffic inside its own network according to some internal protocol that supports the(More)
We study the problem of assigning n tasks to m identical parallel machines in the real-time scheduling setting, where each task recurrently releases jobs that must be completed by their deadlines. The goal is to find a partition of the task set over the machines such that each job that is released by a task can meet its deadline. Since this problem is(More)
We study a dynamic pricing problem for a company that sells a single product to a group of customers over a finite time horizon. These customers are price sensitive and the price of today influences the group of customers of tomorrow. The objective is to set the prices over time so as to maximize revenue. We study two customer models: a multiplicative and(More)
In this article, we consider k -way vertex cut: the problem of finding a graph separator of a given size that decomposes the graph into the maximum number of components. Our main contribution is the derivation of an efficient polynomial-time approximation scheme for the problem on planar graphs. Also, we show that k -way vertex cut is polynomially solvable(More)
During the loading phase of a vessel, only the containers that are on top of their stack are directly accessible. If the container that needs to be loaded next is not the top container, extra moves have to be performed, resulting in an increased loading time. One way to resolve this issue is via a procedure called premarshalling. The goal of premarshalling(More)
We consider the problem of scheduling unit-length jobs on identical machines subject to precedence constraints. We show that natural scheduling rules fail when the precedence constraints form a collection of stars or a collection of complete bipartite graphs. We prove that the problem is in fact NP-hard on collections of stars when the input is given in a(More)
Many combinatorial problems involving weights can be formulated as a so-called ranged problem. That is, their input consists of a universe U , a (succinctly-represented) set family F ⊆ 2 , a weight function ω : U → {1, . . . , N}, and integers 0 ≤ l ≤ u ≤ ∞. Then the problem is to decide whether there is an X ∈ F such that l ≤ ∑ e∈X ω(e) ≤ u. Well-known(More)