198 research outputs found
Application of semidefinite programming to maximize the spectral gap produced by node removal
The smallest positive eigenvalue of the Laplacian of a network is called the
spectral gap and characterizes various dynamics on networks. We propose
mathematical programming methods to maximize the spectral gap of a given
network by removing a fixed number of nodes. We formulate relaxed versions of
the original problem using semidefinite programming and apply them to example
networks.Comment: 1 figure. Short paper presented in CompleNet, Berlin, March 13-15
(2013
Nonlinear Basis Pursuit
In compressive sensing, the basis pursuit algorithm aims to find the sparsest
solution to an underdetermined linear equation system. In this paper, we
generalize basis pursuit to finding the sparsest solution to higher order
nonlinear systems of equations, called nonlinear basis pursuit. In contrast to
the existing nonlinear compressive sensing methods, the new algorithm that
solves the nonlinear basis pursuit problem is convex and not greedy. The novel
algorithm enables the compressive sensing approach to be used for a broader
range of applications where there are nonlinear relationships between the
measurements and the unknowns
Blind Identification via Lifting
Blind system identification is known to be an ill-posed problem and without
further assumptions, no unique solution is at hand. In this contribution, we
are concerned with the task of identifying an ARX model from only output
measurements. We phrase this as a constrained rank minimization problem and
present a relaxed convex formulation to approximate its solution. To make the
problem well posed we assume that the sought input lies in some known linear
subspace.Comment: Submitted to the IFAC World Congress 2014. arXiv admin note: text
overlap with arXiv:1303.671
Solving SDP's in Non-commutative Algebras Part I: The Dual-Scaling Algorithm
Semidefinite programming (SDP) may be viewed as an extension of linear programming (LP), and most interior point methods (IPM s) for LP can be extended to solve SDP problems.However, it is far more difficult to exploit data structures (especially sparsity) in the SDP case.In this paper we will look at the data structure where the SDP data matrices lie in a low dimensional matrix algebra.This data structure occurs in several applications, including the lower bounding of the stability number in certain graphs and the crossing number in complete bipartite graphs.We will show that one can reduce the linear algebra involved in an iteration of an IPM to involve matrices of the size of the dimension of the matrix algebra only.In other words, the original sizes of the data matrices do not appear in the computational complexity bound.In particular, we will work out the details for the dual scaling algorithm, since a dual method is most suitable for the types of applications we have in mind.semidefinite programming;matrix algebras;dual scaling algorithm;exploiting data structure
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