28,384 research outputs found
A Quantum Algorithm To Locate Unknown Hashes For Known N-Grams Within A Large Malware Corpus
Quantum computing has evolved quickly in recent years and is showing
significant benefits in a variety of fields. Malware analysis is one of those
fields that could also take advantage of quantum computing. The combination of
software used to locate the most frequent hashes and -grams between benign
and malicious software (KiloGram) and a quantum search algorithm could be
beneficial, by loading the table of hashes and -grams into a quantum
computer, and thereby speeding up the process of mapping -grams to their
hashes. The first phase will be to use KiloGram to find the top- hashes and
-grams for a large malware corpus. From here, the resulting hash table is
then loaded into a quantum machine. A quantum search algorithm is then used
search among every permutation of the entangled key and value pairs to find the
desired hash value. This prevents one from having to re-compute hashes for a
set of -grams, which can take on average time, whereas the quantum
algorithm could take in the number of table lookups to find the
desired hash values.Comment: IEEE Quantum Week 2020 Conferenc
Relative phase fluctuations of two coupled one-dimensional condensates
We study the relative phase fluctuations of two one-dimensional condensates coupled along their whole extension with a local single-atom interaction. The thermal equilibrium is defined by the competition between independent longitudinal thermally excited phase fluctuations and the coupling between the condensates which locally favors identical phase. We compute the relative phase fluctuations and their correlation length as a function of the temperature and the strength of the coupling
cyclo-Tetra-μ-oxido-tetrakis[3-nitro-4-hydroxyphenylarsenic(III)]
The title compound, [As₄O₄(C₆H₄NO₃)₄], has an eight-membered As₄O₄ ring with a slightly twisted boat-chair conformation. The aryl groups complete the threefold coordination for each As atom. Each OH group forms a strong intramolecular O-H⋯O hydrogen bond to the adjacent NO₂ group, with only weak C-H⋯O, O⋯As [3.036 (6)-3.184 (6) Å] and O⋯O [2.921 (10)-2.930 (10) Å] interactions between tetramers
Efficient minimization of multipole electrostatic potentials in torsion space
The development of models of macromolecular electrostatics capable of delivering improved fidelity to quantum mechanical calculations is an active field of research in computational chemistry. Most molecular force field development takes place in the context of models with full Cartesian coordinate degrees of freedom. Nevertheless, a number of macromolecular modeling programs use a reduced set of conformational variables limited to rotatable bonds. Efficient algorithms for minimizing the energies of macromolecular systems with torsional degrees of freedom have been developed with the assumption that all atom-atom interaction potentials are isotropic. We describe novel modifications to address the anisotropy of higher order multipole terms while retaining the efficiency of these approaches. In addition, we present a treatment for obtaining derivatives of atom-centered tensors with respect to torsional degrees of freedom. We apply these results to enable minimization of the Amoeba multipole electrostatics potential in a system with torsional degrees of freedom, and validate the correctness of the gradients by comparison to finite difference approximations. In the interest of enabling a complete model of electrostatics with implicit treatment of solvent-mediated effects, we also derive expressions for the derivative of solvent accessible surface area with respect to torsional degrees of freedom
An efficient implementation of an implicit FEM scheme for fractional-in-space reaction-diffusion equations
Fractional differential equations are becoming increasingly used as a modelling tool for processes with anomalous diffusion or spatial heterogeneity. However, the presence of a fractional differential operator causes memory (time fractional) or nonlocality (space fractional) issues, which impose a number of computational constraints. In this paper we develop efficient, scalable techniques for solving fractional-in-space reaction diffusion equations using the finite element method on both structured and unstructured grids, and robust techniques for computing the fractional power of a matrix times a vector. Our approach is show-cased by solving the fractional Fisher and fractional Allen-Cahn reaction-diffusion equations in two and three spatial dimensions, and analysing the speed of the travelling wave and size of the interface in terms of the fractional power of the underlying Laplacian operator
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