2,040 research outputs found
On the Smarandache sequences
In this paper, one uses the elementary method to study the convergence of the Smarandache alternate consecutive, reverse Fibonacci sequence and Smarandache multiple sequence
On the Smarandache totient function and the Smarandache power sequence
Talking about Smarandache power function, Smarandache totient function, convergence
Reversible Transient Nucleation in Ionic Solutions as the Precursor of Ion Crystallization
Molecular dynamics simulations for aqueous sodium chloride solutions were
carried out at various concentrations. Supplementary to the Debye-H\"uckel
theory, reversible transient nucleation of ions was observed even in dilute
solutions. The average size of formed ion clusters and the lifetime of ion
pairs increase with concentration until the saturation point, when ion clusters
become stable and individual ions adjust their positions to form ordered
lattice structures, leading to irreversible ion crystallization, which is
beyond the description of the classical nucleation theory.Comment: 4 pages, 5 figures, and 46 reference
One-step hydrothermal synthesis of fluorescence carbon quantum dots with high product yield and quantum yield
A one-step hydrothermal synthesis of nitrogen and silicon co-doped fluorescence carbon quantum dots (N,Si-CQDs), from citric acid monohydrate and silane coupling agent KH-792 with a high product yield (PY) of 52.56% and high quantum yield (QY) of 97.32%, was developed. This greatly improves both the PY and QY of CQDs and provides a new approach for a large-scale production of high-quality CQDs. Furthermore, N,Si-CQDs were employed as phosphors without dispersants to fabricate white light-emitting diodes (WLEDs) with the color coordinates at (0.29, 0.32). It is suggested that N,Si-CQDs have great potential as promising fluorescent materials to be applied in WLEDs.Peer reviewe
Mismatched Estimation in Large Linear Systems
We study the excess mean square error (EMSE) above the minimum mean square
error (MMSE) in large linear systems where the posterior mean estimator (PME)
is evaluated with a postulated prior that differs from the true prior of the
input signal. We focus on large linear systems where the measurements are
acquired via an independent and identically distributed random matrix, and are
corrupted by additive white Gaussian noise (AWGN). The relationship between the
EMSE in large linear systems and EMSE in scalar channels is derived, and closed
form approximations are provided. Our analysis is based on the decoupling
principle, which links scalar channels to large linear system analyses.
Numerical examples demonstrate that our closed form approximations are
accurate.Comment: 5 pages, 2 figure
Compressive Imaging via Approximate Message Passing with Image Denoising
We consider compressive imaging problems, where images are reconstructed from
a reduced number of linear measurements. Our objective is to improve over
existing compressive imaging algorithms in terms of both reconstruction error
and runtime. To pursue our objective, we propose compressive imaging algorithms
that employ the approximate message passing (AMP) framework. AMP is an
iterative signal reconstruction algorithm that performs scalar denoising at
each iteration; in order for AMP to reconstruct the original input signal well,
a good denoiser must be used. We apply two wavelet based image denoisers within
AMP. The first denoiser is the "amplitude-scaleinvariant Bayes estimator"
(ABE), and the second is an adaptive Wiener filter; we call our AMP based
algorithms for compressive imaging AMP-ABE and AMP-Wiener. Numerical results
show that both AMP-ABE and AMP-Wiener significantly improve over the state of
the art in terms of runtime. In terms of reconstruction quality, AMP-Wiener
offers lower mean square error (MSE) than existing compressive imaging
algorithms. In contrast, AMP-ABE has higher MSE, because ABE does not denoise
as well as the adaptive Wiener filter.Comment: 15 pages; 2 tables; 7 figures; to appear in IEEE Trans. Signal
Proces
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