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We present an iterative algorithm (BIN) for scaling all the rows and columns of a real symmetric matrix to unit 2-norm. We study the theoretical convergence properties and its relation to optimal conditioning. Numerical experiments show that BIN requires 2–4 matrix-vector multiplications to obtain an adequate scaling, and in many cases significantly reduces(More)
Laplacian matrices of graphs arise in large-scale computational applications such as semi-supervised machine learning; spectral clustering of images, genetic data and web pages; transportation network flows; electrical resistor circuits; and elliptic partial differential equations discretized on unstructured grids with finite elements. A Lean Algebraic(More)
The linear systems arising in lattice QCD pose significant challenges for traditional iterative solvers. For physically interesting values of the so-called quark mass, these systems are nearly singular, indicating the need for efficient preconditioners. However, multi-level preconditioners cannot easily be constructed because the Dirac operator associated(More)
Founder populations and large pedigrees offer many well-known advantages for genetic mapping studies, including cost-efficient study designs. Here, we describe PRIMAL (PedigRee IMputation ALgorithm), a fast and accurate pedigree-based phasing and imputation algorithm for founder populations. PRIMAL incorporates both existing and original ideas, such as a(More)
We present a software architecture that federates data from multiple heterogeneous health informatics data sources owned by multiple organizations. The architecture builds upon state-of-the-art open-source Java and XML frameworks in innovative ways. It consists of (a) federated query engine, which manages federated queries and result set aggregation via a(More)
The Federated Utah Research and Translational Health e-Repository (FURTHeR) is a Utah statewide informatics platform for the new Center for Clinical and Translational Science at the University of Utah. We have been working on one of FURTHeR's key components, a federated query engine for heterogeneous resources, that we believe has the potential to meet some(More)
We present software architecture to federate data from multiple heterogeneous health informatics data sources owned by multiple organizations. The architecture builds upon state-of-the-art open-source Java and XML frameworks in innovative ways. It consists of (a) federated query engine, which manages federated queries and result set aggregation; and (b)(More)
Common variants at many loci have been robustly associated with asthma but explain little of the overall genetic risk. Here we investigate the role of rare (<1%) and low-frequency (1-5%) variants using the Illumina HumanExome BeadChip array in 4,794 asthma cases, 4,707 non-asthmatic controls and 590 case-parent trios representing European Americans, African(More)