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ORDER
2002
104views more  ORDER 2002»
14 years 11 months ago
Partially Well-Ordered Closed Sets of Permutations
It is known that the "pattern containment" order on permutations is not a partial well-order. Nevertheless, many naturally defined subsets of permutations are partially ...
Mike D. Atkinson, Max Murphy, Nikola Ruskuc
MOR
2008
169views more  MOR 2008»
14 years 11 months ago
The Flow Set with Partial Order
The flow set with partial order is a mixed-integer set described by a budget on total flow and a partial order on the arcs that may carry positive flow. This set is a common substr...
Alper Atamtürk, Muhong Zhang
ANOR
2008
69views more  ANOR 2008»
14 years 11 months ago
NP-hardness results for the aggregation of linear orders into median orders
Abstract Given a collection of individual preferences defined on a same finite set of candidates, we consider the problem of aggregating them into a collective preference minimizin...
Olivier Hudry
BSL
2000
153views more  BSL 2000»
14 years 11 months ago
Combinatorics with definable sets: Euler characteristics and Grothendieck rings
We recall the notions of weak and strong Euler characteristics on a first order structure and make explicit the notion of a Grothendieck ring of a structure. We define partially or...
Jan Krajícek, Thomas Scanlon
EJC
2008
14 years 11 months ago
Pattern classes of permutations via bijections between linearly ordered sets
Abstract. A pattern class is a set of permutations closed under pattern involvement or, equivalently, defined by certain subsequence avoidance conditions. Any pattern class X which...
Sophie Huczynska, Nikola Ruskuc