26,100 research outputs found
Decision making with decision event graphs
We introduce a new modelling representation, the Decision Event Graph (DEG), for asymmetric
multistage decision problems. The DEG explicitly encodes conditional independences
and has additional significant advantages over other representations of asymmetric decision
problems. The colouring of edges makes it possible to identify conditional independences on
decision trees, and these coloured trees serve as a basis for the construction of the DEG.
We provide an efficient backward-induction algorithm for finding optimal decision rules on
DEGs, and work through an example showing the efficacy of these graphs. Simplifications of
the topology of a DEG admit analogues to the sufficiency principle and barren node deletion
steps used with influence diagrams
Quadratic Form Expansions for Unitaries
We introduce techniques to analyze unitary operations in terms of quadratic
form expansions, a form similar to a sum over paths in the computational basis
when the phase contributed by each path is described by a quadratic form over
. We show how to relate such a form to an entangled resource akin to
that of the one-way measurement model of quantum computing. Using this, we
describe various conditions under which it is possible to efficiently implement
a unitary operation U, either when provided a quadratic form expansion for U as
input, or by finding a quadratic form expansion for U from other input data.Comment: 20 pages, 3 figures; (extended version of) accepted submission to TQC
200
The Radio Number of Grid Graphs
The radio number problem uses a graph-theoretical model to simulate optimal
frequency assignments on wireless networks. A radio labeling of a connected
graph is a function such that for every pair
of vertices , we have where denotes the diameter of and
the distance between vertices and . Let be the
difference between the greatest label and least label assigned to . Then,
the \textit{radio number} of a graph is defined as the minimum
value of over all radio labelings of . So far, there have
been few results on the radio number of the grid graph: In 2009 Calles and
Gomez gave an upper and lower bound for square grids, and in 2008 Flores and
Lewis were unable to completely determine the radio number of the ladder graph
(a 2 by grid). In this paper, we completely determine the radio number of
the grid graph for , characterizing three subcases of the
problem and providing a closed-form solution to each. These results have
implications in the optimization of radio frequency assignment in wireless
networks such as cell towers and environmental sensors.Comment: 17 pages, 7 figure
The Geometry of Interaction of Differential Interaction Nets
The Geometry of Interaction purpose is to give a semantic of proofs or
programs accounting for their dynamics. The initial presentation, translated as
an algebraic weighting of paths in proofnets, led to a better characterization
of the lambda-calculus optimal reduction. Recently Ehrhard and Regnier have
introduced an extension of the Multiplicative Exponential fragment of Linear
Logic (MELL) that is able to express non-deterministic behaviour of programs
and a proofnet-like calculus: Differential Interaction Nets. This paper
constructs a proper Geometry of Interaction (GoI) for this extension. We
consider it both as an algebraic theory and as a concrete reversible
computation. We draw links between this GoI and the one of MELL. As a
by-product we give for the first time an equational theory suitable for the GoI
of the Multiplicative Additive fragment of Linear Logic.Comment: 20 pagee, to be published in the proceedings of LICS0
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