400 research outputs found
Smooth monotonous functions reconstruction
We consider the problem of smooth monotonous function reconstruction on the basis of it (exact or approached) values in some points We offer a variant of accurate statement of the problem and methods of its exact and approached solution in spreadsheets Examples show that existing methods of reconstruction not always provide monotonicity of the reconstructed functionFunction of one variable; smoothness; monotonicity; reconstruction; random errors
Sparse polynomial space approach to dissipative quantum systems: Application to the sub-ohmic spin-boson model
We propose a general numerical approach to open quantum systems with a
coupling to bath degrees of freedom. The technique combines the methodology of
polynomial expansions of spectral functions with the sparse grid concept from
interpolation theory. Thereby we construct a Hilbert space of moderate
dimension to represent the bath degrees of freedom, which allows us to perform
highly accurate and efficient calculations of static, spectral and dynamic
quantities using standard exact diagonalization algorithms. The strength of the
approach is demonstrated for the phase transition, critical behaviour, and
dissipative spin dynamics in the spin boson modelComment: 4 pages, 4 figures, revised version accepted for publication in PR
Coupled IGMM-GANs for improved generative adversarial anomaly detection
Detecting anomalies and outliers in data has a number of applications including hazard sensing, fraud detection, and systems management. While generative adversarial networks seem like a natural fit for addressing these challenges, we find that existing GAN based anomaly detection algorithms perform poorly due to their inability to handle multimodal patterns. For this purpose we introduce an infinite Gaussian mixture model coupled with (bi-directional) generative adversarial networks, IGMM-GAN, that facilitates multimodal anomaly detection. We illustrate our methodology and its improvement over existing GAN anomaly detection on the MNIST dataset
Tractability of multivariate problems for standard and linear information in the worst case setting: part II
We study QPT (quasi-polynomial tractability) in the worst case setting for
linear tensor product problems defined over Hilbert spaces. We assume that the
domain space is a reproducing kernel Hilbert space so that function values are
well defined. We prove QPT for algorithms that use only function values under
the three assumptions:
1) the minimal errors for the univariate case decay polynomially fast to
zero,
2) the largest singular value for the univariate case is simple and
3) the eigenfunction corresponding to the largest singular value is a
multiple of the function value at some point.
The first two assumptions are necessary for QPT. The third assumption is
necessary for QPT for some Hilbert spaces
Joint Application Of Market And Income Approaches To New Machines And Equipment Valuation Under Uncertainty
A market, income, or cost approach is a term used to describe the methods used to value assets. Meanwhile, by combining multiple methodologies, correct valuation methods can be obtained. One of these ways is based on a formula given by D.S. Lvov at one point, which connects the market values of the assessed machine and its analogue while accounting for changes in machine operating characteristics and usable life. However, when calculating the formula, it is assumed that the machine's properties do not vary over time. For a case where the operating parameters of machines fluctuate throughout operation and the useful life is random, we suggest a generalization of this formula
Universal linear relations between susceptibility and Tc in cuprates
We developed an experimental method for measuring the intrinsic
susceptibility \chi of powder of cuprate superconductors in the zero field
limit using a DC-magnetometer. The method is tested with lead spheres. Using
this method we determine \chi for a number of cuprate families as a function of
doping. A universal linear (and not proportionality) relation between Tc and
\chi is found. We suggest possible explanations for this phenomenon.Comment: Accepted for publication in PR
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