143 research outputs found

    Approaches to creating anonymous patient database

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    Health care providers, health plans and health care clearinghouses collect patient medical data derived from their normal operations every day. These patient data can greatly benefit the health care organization if data mining techniques are applied upon these data sets. However, individual identifiable patient information needs to be protected in accordance with Health Insurance Portability and Accountability Act (HIPAA), and the quality of patient data also needs to be ensured in order for data mining tasks achieve accurate results. This thesis describes a patient data transformation system which transforms patient data into high quality and anonymous patient records that is suitable for data mining purposes.;This document discusses the underlying technologies, features implemented in the prototype, and the methodologies used in developing the software. The prototype emphasizes the patient privacy and quality of the patient data as well as software scalability and portability. Preliminary experience of its use is presented. A performance analysis of the system\u27s behavior has also been done

    Link between K-absorption edges and thermodynamic properties of warm-dense plasmas established by improved first-principles method

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    A precise calculation that translates shifts of X-ray K-absorption edges to variations of thermodynamic properties allows quantitative characterization of interior thermodynamic properties of warm dense plasmas by X-ray absorption techniques, which provides essential information for inertial confinement fusion and other astrophysical applications. We show that this interpretation can be achieved through an improved first-principles method. Our calculation shows that the shift of K-edges exhibits selective sensitivity to thermal parameters and thus would be a suitable temperature index to warm dense plasmas. We also show with a simple model that the shift of K-edges can be used to detect inhomogeneity inside warm dense plasmas when combined with other experimental tools

    Deep Network Approximation: Achieving Arbitrary Accuracy with Fixed Number of Neurons

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    This paper develops simple feed-forward neural networks that achieve the universal approximation property for all continuous functions with a fixed finite number of neurons. These neural networks are simple because they are designed with a simple and computable continuous activation function σ\sigma leveraging a triangular-wave function and the softsign function. We prove that σ\sigma-activated networks with width 36d(2d+1)36d(2d+1) and depth 1111 can approximate any continuous function on a dd-dimensional hypercube within an arbitrarily small error. Hence, for supervised learning and its related regression problems, the hypothesis space generated by these networks with a size not smaller than 36d(2d+1)×1136d(2d+1)\times 11 is dense in the continuous function space C([a,b]d)C([a,b]^d) and therefore dense in the Lebesgue spaces Lp([a,b]d)L^p([a,b]^d) for p∈[1,∞)p\in [1,\infty). Furthermore, classification functions arising from image and signal classification are in the hypothesis space generated by σ\sigma-activated networks with width 36d(2d+1)36d(2d+1) and depth 1212, when there exist pairwise disjoint bounded closed subsets of Rd\mathbb{R}^d such that the samples of the same class are located in the same subset. Finally, we use numerical experimentation to show that replacing the ReLU activation function by ours would improve the experiment results

    First-Principles Calculation of Principal Hugoniot and K-Shell X-ray Absorption Spectra for Warm Dense KCl

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    Principal Hugoniot and K-shell X-ray absorption spectra of warm dense KCl are calculated using the first-principles molecular dynamics method. Evolution of electronic structures as well as the influence of the approximate description of ionization on pressure (caused by the underestimation of the energy gap between conduction bands and valence bands) in the first-principles method are illustrated by the calculation. Pressure ionization and thermal smearing are shown as the major factors to prevent the deviation of pressure from global accumulation along the Hugoniot. In addition, cancellation between electronic kinetic pressure and virial pressure further reduces the deviation. The calculation of X-ray absorption spectra shows that the band gap of KCl persists after the pressure ionization of the 3p3p electrons of Cl and K taking place at lower energy, which provides a detailed understanding to the evolution of electronic structures of warm dense matter
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