Many constraint problems exhibit dominance relations which can be exploited for dramatic reductions in search space. Dominance relations are a generalization of symmetry and conditional symmetry. However, unlike symmetry breaking which is relatively well studied, dominance breaking techniques are not very well understood and are not commonly applied. In this paper, we present formal definitions...

The two major paradigms in the theoretical agency literature are moral hazard (i.e., hidden action) and adverse selection (i.e., hidden information). Prior research typically solves these problems in isolation, as opposed to simultaneously incorporating both adverse selection and moral hazard features. We formulate two complementary generalized principalagent models that incorporate features ob...

We discuss diierent methods of reducing symmetry in CSPs where the variables correspond to the cells of a matrix, and both the rows and the columns of the matrix are interchangeable. Two basic approaches are considered: adding symmetry-breaking constraints to the model, and breaking symmetry during search. We also show how the two approaches can be combined in this case. We empirically compare ...

In an auction market where the price of each selling item is restricted to an admissible interval (price rigidities), a Walrasian equilibrium usually fails to exist. Dreze (1975) introduced a variant concept of Walrasian equilibrium based on rationing systems, named constrained Walrasian equilibrium, for modelling an economy with price rigidities. Talman and Yang (2008) further refined the conc...

where x, c, c ∈ R1 , x, c, c ∈ R2 , b ∈ R, A1 is an m × n1 matrix, A2 is an m × n2 matrix, and T denotes the transposition. Such problems may arise when there are two decision makers at different hierarchical levels having joint constraints and different and possibly conflicting objectives. The decision-making process is sequential. The leader controlling the variables of x has the first choice...

most part of durum wheat is produced in semitropical dryland regions in iran. heat and drought stresses are the main constraints in these regions. so, identification of durum wheat cultivars with high yield and tolerant to these stresses is the main breeding strategy in dryland agricultural research institute. the genotype capeiti was evaluated at gachsaran agricultural research station from 19...

Solution symmetries in integer linear programs often yield long Branch-and-Bound based solution processes. We propose a method for finding elements of the permutation group of solution symmetries, and two different types of symmetry-breaking constraints to eliminate these symmetries at the modelling level. We discuss some preliminary computational results.