Latest in physics.comp-ph

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On mean-field theories of dynamics in supercooled liquidsJun 13 2019We develop a hybrid numerical approach to extract the exact memory function K(t) of a tagged particle in three-dimensional glass-forming liquids. We compare the behavior of the exact memory kernel to two mean-field approaches, namely the standard mode-coupling ... More
Modeling the Dynamics of PDE Systems with Physics-Constrained Deep Auto-Regressive NetworksJun 13 2019In recent years, deep learning has proven to be a viable methodology for surrogate modeling and uncertainty quantification for a vast number of physical systems. However, in their traditional form, such models require a large amount of training data. ... More
A stabilized DG cut cell method for discretizing the linear transport equationJun 13 2019We present new stabilization terms for solving the linear transport equation on a cut cell mesh using the discontinuous Galerkin (DG) method in two dimensions with piecewise linear polynomials. The goal is to allow for explicit time stepping schemes, ... More
Designing modular 3D printed reinforcement of wound composite tubes with semidefinite programmingJun 13 2019Fueled by their excellent stiffness-to-weight ratio and the availability of mature manufacturing technologies, filament wound carbon fiber reinforced polymers represent ideal materials for thin-walled laminate structures. However, their strong anisotropy ... More
A comparative study of immersed boundary method and interpolated bounce-back scheme for no-slip boundary treatment in the lattice Boltzmann method: Part II, turbulent flowsJun 13 2019In the first part of this study, we compared the performances of two categories of no-slip boundary treatments, i.e., the interpolated bounce-back schemes and the immersed boundary methods in a series of laminar flow simulations within the lattice Boltzmann ... More
A comparative study of immersed boundary method and interpolated bounce-back scheme for no-slip boundary treatment in the lattice Boltzmann method: Part I, laminar flowsJun 13 2019The interpolated bounce-back scheme and the immersed boundary method are the two most popular algorithms in treating a no-slip boundary on curved surfaces in the lattice Boltzmann method. While those algorithms are frequently implemented in the numerical ... More
Thermally induced band gap increase and high thermoelectric figure of merit of n-type PbTeJun 12 2019Unlike in many other semiconductors, the band gap of PbTe increases considerably with temperature. We compute the thermoelectric transport properties of n-type PbTe from first principles including the temperature variation of the electronic band structure. ... More
Developing an improved Crystal Graph Convolutional Neural Network framework for accelerated materials discoveryJun 12 2019The recently proposed crystal graph convolutional neural network (CGCNN) offers a highly versatile and accurate machine learning (ML) framework by learning material properties directly from graph-like representations of crystal structures ("crystal graphs"). ... More
A Model to Search for Synthesizable MoleculesJun 12 2019Deep generative models are able to suggest new organic molecules by generating strings, trees, and graphs representing their structure. While such models allow one to generate molecules with desirable properties, they give no guarantees that the molecules ... More
Is Deep Learning an RG Flow?Jun 12 2019Although there has been a rapid development of practical applications, theoretical explanations of deep learning are in their infancy. A possible starting point suggests that deep learning performs a sophisticated coarse graining. Coarse graining is the ... More
Voltage-induced high-speed DW motion in a synthetic antiferromagnetJun 12 2019Voltage-induced motion of a magnetic domain wall (DW) has potential in developing novel devices with ultralow dissipation. However, the speed for the voltage-induced DW motion (VIDWM) in a single ferromagnetic layer is usually very low. In this work, ... More
Long-time persistence of hydrodynamic memory boosts microparticle transportJun 12 2019An accelerating particle in a viscous liquid leaves an imprint of its past velocity as shear stress, resulting in the long-time $t^{-3/2}$ decay of velocity autocorrelations. For nonuniform particle motion at low Reynolds number, the Basset-Boussinesq-Oseen ... More
Can we find steady-state solutions to multiscale rarefied gas flows within dozens of iterations?Jun 11 2019One of the central problems in the study of rarefied gas dynamics is to find the steady-state solution of the Boltzmann equation quickly. When the Knudsen number is large, i.e. the system is highly rarefied, the conventional iteration scheme can lead ... More
High pressure melt locus of iron from atom-in-jellium calculationsJun 11 2019Although usually considered as a technique for predicting electron states in dense plasmas, atom-in-jellium calculations can be used to predict the mean displacement of the ion from its equilibrium position in colder matter, as a function of compression ... More
A Hybrid multiphase model based on lattice Boltzmann method direct simulationsJun 11 2019By means of the multicomponent Shan-Chen lattice Boltzmann method (LBM), we investigate the multiphase flow through porous media. Despite the excellent accuracy of the LBM, large domains result in unaffordable computational expenses. The Hybrid model ... More
Modeling emission of acoustic energy during bubble expansion in PICO bubble chambersJun 11 2019The PICO experiment uses bubble chambers filled with superheated C$_3$F$_8$ for spin-dependent WIMP dark matter searches. One of the main sources of background in these detectors is alpha particles from decays of environmental $^{222}\mathrm{Rn}$, which ... More
Thermal conductivity and thermal rectification of nanoporous graphene: A molecular dynamics simulationJun 11 2019Using non-equilibrium molecular dynamics (NEMD) simulation, we study thermal properties of the so-called nanoporous graphene (NPG) sheet which contains a series of nanoporous in an ordered way and was synthesized recently (Science 360 (2018), 199). The ... More
Control contribution identifies top driver nodes in complex networksJun 11 2019We propose a new measure to quantify the impact of a node $i$ in controlling a directed network. This measure, called `control contribution' $\mathcal{C}_{i}$, combines the probability for node $i$ to appear in a set of driver nodes and the probability ... More
Learning Symmetries of Classical Integrable SystemsJun 11 2019The solution of problems in physics is often facilitated by a change of variables. In this work we present neural transformations to learn symmetries of Hamiltonian mechanical systems. Maintaining the Hamiltonian structure requires novel network architectures ... More
A volume of fluid framework for interface-resolved simulations of vaporizing liquid-gas flowsJun 11 2019This work demonstrates a computational framework for simulating vaporizing, liquid-gas flows. It is developed for the general vaporization problem which solves the vaporization rate based as from the local thermodynamic equilibrium of the liquid-gas system. ... More
Evaluating two-electron-repulsion integrals over arbitrary orbitals using Zero Variance Monte Carlo: Application to Full Configuration Interaction calculations with Slater-type orbitalsJun 11 2019A Monte Carlo method for evaluating multi-center two-electron-repulsion integrals over any type of orbitals (Slater, Sturmian, finite-range, numerical, etc.) is presented. The approach is based on a simple and universal (orbital-independent) gaussian ... More
Quantification model of X-ray fluorescence analysis based on iterative Monte Carlo procedureJun 11 2019Iterative Monte Carlo algorithm has been constructed and tested for quantification of X-ray fluorescence analysis in order to determine the atomic composition of solid materials. The calculation model uses simulation code MCNP6 that describes the excitation ... More
Towards Photoferroic Materials by Design: Recent Progresses and PerspectiveJun 11 2019The use of photoferroic materials that combine ferroelectric and light harvesting properties in a photovoltaic device is a promising route to significantly improve the efficiency of solar cells. These materials do not require the formation of a p-n junction ... More
Applying the tempered Lefschetz thimble method to the Hubbard model away from half-fillingJun 10 2019The tempered Lefschetz thimble method [arXiv:1703.00861] is a parallel-tempering algorithm to solve the sign problem in Monte Carlo simulations. It uses the flow time of the antiholomorphic gradient flow as a tempering parameter and is expected to tame ... More
Mie Scattering of Phonons by Point Defects in IV-VI Semiconductors PbTe and GeTeJun 10 2019The scattering of thermal acoustic phonons by point defects in solids has been widely assumed the Rayleigh scattering type. In contrast to this conventional perception, using an ab initio Green's function approach, we show that the scattering by point ... More
Coupled Cluster as an impurity solver for Green's function embedding methodsJun 10 2019We investigate the performance of Green's function coupled cluster singles and doubles (CCSD) method as a solver for Green's function embedding methods. To develop an efficient CC solver, we construct the one-particle Green's function from the coupled ... More
Data-driven Reconstruction of Nonlinear Dynamics from Sparse ObservationJun 10 2019We present a data-driven model to reconstruct nonlinear dynamics from a very sparse times series data, which relies on the strength of the echo state network (ESN) in learning nonlinear representation of data. With an assumption of the universal function ... More
A fast implicit solver for semiconductor models in one space dimensionJun 10 2019Several different approaches are proposed for solving fully implicit discretizations of a simplified Boltzmann-Poisson system with a linear relaxation-type collision kernel. This system models the evolution of free electrons in semiconductor devices under ... More
On the Calculation of IR Spectra with a Fully Polarizable QM/MM Approach Based on Fluctuating Charges and Fluctuating DipolesJun 10 2019The fully polarizable QM/MM approach based on fluctuating charges and fluctuating dipoles, named QM/FQF{\mu} (J. Chem. Theory Comput. 2019, 15, 2233-2245), is extended to the evaluation of nuclear gradients and the calculation of IR spectra of molecular ... More
Electronic Transitions for a Fully Polarizable QM/MM Approach Based on Fluctuating Charges and Fluctuating Dipoles: Linear and Corrected Linear Response RegimesJun 10 2019Fully polarizable QM/MM approach based on fluctuating charges and fluctuating dipoles, named QM/FQF{\mu} (J. Chem. Theory Comput. 2019, 15 2233-2245), is extended to the calculation of vertical excitation energies of solvated molecular systems. Excitation ... More
An explicit meshless point collocation solver for incompressible Navier-Stokes equationsJun 10 2019We present a strong form, meshless point collocation explicit solver for the numerical solution of the transient, incompressible, viscous Navier-Stokes (N-S) equations in two dimensions. We numerically solve the governing flow equations in their stream ... More
Deep-learning-based reduced-order modeling for subsurface flow simulationJun 09 2019A new deep-learning-based reduced-order modeling (ROM) framework is proposed for application in subsurface flow simulation. The reduced-order model is based on an existing embed-to-control (E2C) framework and includes an auto-encoder, which projects the ... More
Accelerated Piston Problem and High Order Moving Boundary Tracking Method for Compressible Fluid FlowsJun 09 2019Reliable tracking of moving boundaries is important for the simulation of compressible fluid flows and there are a lot of contributions in literature. We recognize from the classical piston problem, a typical moving boundary problem in gas dynamics, that ... More
Learning Radiative Transfer Models for Climate Change Applications in Imaging SpectroscopyJun 08 2019According to a recent investigation, an estimated 33-50% of the world's coral reefs have undergone degradation, believed to be as a result of climate change. A strong driver of climate change and the subsequent environmental impact are greenhouse gases ... More
On a thermodynamic framework for developing boundary conditions for Korteweg fluidsJun 08 2019We provide a derivation of several classes of boundary conditions for fluids of Korteweg-type using a simple and transparent thermodynamic approach that automatically guarentees that the derived boundary conditions are compatible with the second law of ... More
Modified symmetry technique for mitigation of flow leak near corners for compressible inviscid fluid flowJun 08 2019Using the standard symmetry technique for applying boundary conditions for free slip and flat walls with corners will lead to flow leak through the wall near corners (violation of no penetration condition) and a corresponding error in prediction of pressure. ... More
The driving force behind the distortion of one-dimensional monatomic chains - Peierls theorem revisitedJun 08 2019The onset of distortion in one-dimensional monatomic chains with partially filled valence bands is considered to be well-established by the Peierls theorem, which associates the distortion with the formation of a band gap and a subsequent gain in energy. ... More
Transition to metallization in warm dense helium-hydrogen mixtures using stochastic density functional theory within the Kubo-Greenwood formalismJun 07 2019Abstract The Kubo-Greenwood (KG) formula is often used in conjunction with Kohn-Sham (KS) density functional theory (DFT) to compute the optical conductivity, particularly for warm dense mater. For applying the KG formula, all KS eigenstates and eigenvalues ... More
Harnessing elasticity to generate self-oscillation via an electrohydrodynamic instabilityJun 07 2019Under a steady DC electric field of sufficient strength, a weakly conducting dielectric sphere in a dielectric solvent with higher conductivity can undergo spontaneous spinning (Quincke rotation) through a pitchfork bifurcation. We design an object composed ... More
Machine Learning Prediction of Accurate Atomization Energies of Organic Molecules from Low-Fidelity Quantum Chemical CalculationsJun 07 2019Recent studies illustrate how machine learning (ML) can be used to bypass a core challenge of molecular modeling: the tradeoff between accuracy and computational cost. Here, we assess multiple ML approaches for predicting the atomization energy of organic ... More
A resistive extension for ideal MHDJun 07 2019We present an extension to the special relativistic, ideal magnetohydrodynamics (MHD) equations, designed to capture effects due to resistivity. The extension takes the simple form of an additional source term which, when implemented numerically, is shown ... More
Pressure-robustness in quasi-optimal a priori estimates for the Stokes problemJun 07 2019Recent analysis of the divergence constraint in the incompressible Stokes/Navier--Stokes problem has stressed the importance of equivalence classes of forces and how it plays a fundamental role for an accurate space discretization. Two forces in the momentum ... More
Provably Optimal Parallel Transport Sweeps on Semi-Structured GridsJun 07 2019We have found provably optimal algorithms for full-domain discrete-ordinate transport sweeps on a class of grids in 2D and 3D Cartesian geometry that are regular at a coarse level but arbitrary within the coarse blocks. We describe these algorithms and ... More
Cormorant: Covariant Molecular Neural NetworksJun 06 2019We propose Cormorant, a rotationally covariant neural network architecture for learning the behavior and properties of complex many-body physical systems. We apply these networks to molecular systems with two goals: learning atomic potential energy surfaces ... More
Topology optimization of unsaturated flows in multi-material porous media: application to a simple diaper modelJun 06 2019We present a mathematical approach to optimize the material distribution for fluid transport in unsaturated porous media. Our benchmark problem is a simplified diaper model as an exemplary liquid absorber. Our model has up to three materials with vastly ... More
Dynamic behavior of mechanical cloaks designed by direct lattice transformationJun 06 2019Steering waves in elastic solids is more demanding than steering waves in electromagnetism or acoustics. As a result, designing material distributions which are the counterpart of optical invisibility cloaks in elasticity poses a major challenge. Waves ... More
A phase inversion benchmark for multiscale multiphase flowsJun 06 2019A series of benchmarks based on the physical situation of "phase inversion" between two incompressible liquids is presented. These benchmarks aim at progressing toward the direct numerical simulation of two-phase flows. Several CFD codes developed in ... More
Theoretical evidence for the sensitivity of charge-rearrangement-enhanced x-ray ionization to molecular sizeJun 06 2019It was recently discovered that molecular ionization at high x-ray intensity is enhanced, in comparison with that of isolated atoms, through a phenomenon called CREXIM (charge-rearrangement-enhanced x-ray ionization of molecules). X-ray absorption selectively ... More
Validating fast-ion wall-load IR analysis-methods against W7-X NBI empty-torus experimentJun 06 2019The first neutral beam injection (NBI) experiments in Wendelstein 7-X (W7-X) stellarator were conducted in the summer of 2018. The NBI system is used to heat the magnetically confined plasma by neutralising an accelerated hydrogen ion beam and directing ... More
OnionNet: a multiple-layer inter-molecular contact based convolutional neural network for protein-ligand binding affinity predictionJun 06 2019Computational drug discovery provides an efficient tool helping large scale lead molecules screening. One of the major tasks of lead discovery is identifying molecules with promising binding affinities towards a target, a protein in general. The accuracies ... More
Learning to regularize with a variational autoencoder for hydrologic inverse analysisJun 06 2019Inverse problems often involve matching observational data using a physical model that takes a large number of parameters as input. These problems tend to be under-constrained and require regularization to impose additional structure on the solution in ... More
Surrogate Modeling for Fluid Flows Based on Physics-Constrained Deep Learning Without Simulation DataJun 06 2019Numerical simulations on fluid dynamics problems primarily rely on spatially or/and temporally discretization of the governing equation into the finite-dimensional algebraic system solved by computers. Due to complicated nature of the physics and geometry, ... More
Revelation of Carrier Recombination Mechanism at Defects in Wide Bandgap 2D Materials from First-principlesJun 05 2019Identification and design of defects in two-dimensional (2D) materials as promising single photon emitters (SPE) requires a deep understanding of underlying carrier recombination mechanisms. Yet, the dominant mechanism of carrier recombination at defects ... More
The formation and dissipation of current sheets and shocks due to compressive waves in a stratified atmosphere containing a magnetic nullJun 05 2019We study the propagation and dissipation of magnetohydrodynamic waves in a set of numerical models that each include a solar--like stratified atmosphere and a magnetic field with a null point. All simulations have the same magnetic field configuration ... More
Easing the Monte Carlo sign problemJun 05 2019Quantum Monte Carlo (QMC) methods are the gold standard for studying equilibrium properties of quantum many-body systems -- their phase transitions, their ground and thermal state properties. However, in many interesting situations QMC methods are faced ... More
Parallelized Kalman-Filter-Based Reconstruction of Particle Tracks on Many-Core Architectures with the CMS DetectorJun 05 2019In the High-Luminosity Large Hadron Collider (HL-LHC), one of the most challenging computational problems is expected to be finding and fitting charged-particle tracks during event reconstruction. The methods currently in use at the LHC are based on the ... More
Combining Physics-Based Domain Knowledge and Machine Learning using Variational Gaussian Processes with Explicit Linear PriorJun 05 2019Centuries of development in natural sciences and mathematical modeling provide valuable domain expert knowledge that has yet to be explored for the development of machine learning models. When modeling complex physical systems, both domain knowledge and ... More
Predicting Compressive Strength of Consolidated Molecular Solids Using Computer Vision and Deep LearningJun 05 2019We explore the application of computer vision and machine learning (ML) techniques to predict material properties (e.g., compressive strength) based on SEM images of material microstructure. We show that it is possible to train ML models to predict materials ... More
Anisotropic Tensor Renormalization GroupJun 05 2019We propose a new tensor renormalization group algorithm, Anisotropic Tensor Renormalization Group (ATRG), for lattice models in arbitrary dimensions. The proposed method shares the same versatility with the Higher-Order Tensor Renormalization Group (HOTRG) ... More
Thermal Boundary Characteristics of Homo-/Heterogeneous InterfacesJun 05 2019The interface of two solids in contact introduces a thermal boundary resistance (TBR), which is challenging to measure from experiments. Besides, if the interface is reactive, it can form an intermediate recrystallized or amorphous region, and extra influencing ... More
Modal analysis for nanoplasmonics with nonlocal material propertiesJun 05 2019Plasmonic devices with feature sizes of few nanometers exhibit effects which can be described by the nonlocal hydrodynamic Drude model. We demonstrate how to exploit contour integral methods for computing eigenfrequencies and resonant states of such systems. ... More
On the accuracy of stiff-accurate diagonal implicit Runge-Kutta methods for finite volume based Navier-Stokes equationsJun 05 2019The paper aims at developing low-storage implicit Runge-Kutta methods which are easy to implement and achieve higher-order of convergence for both the velocity and pressure in the finite volume formulation of the incompressible Navier-Stokes equations ... More
An ALE-type discrete unified gas kinetic scheme for low-speed continuum and rarefied flow simulations with moving boundariesJun 05 2019In this paper, the original discrete unified gas kinetic scheme (DUGKS) is extended to arbitrary Lagrangian-Eulerian (ALE) framework for simulating the low-speed continuum and rarefied flows with moving boundaries. For ALE method, the mesh moving velocity ... More
Advanced analytical method based on Green's theorem for light transmission through subwavelength structures of multiple configurations in metal filmsJun 05 2019Nowadays, methods for analyzing light transmission through subwavelength structures are typically based on the mode expansion with Fourier series. However, these methods require sophisticated techniques and the solutions are in $k$-space, where the coupling ... More
A Multi-Pass GAN for Fluid Flow Super-ResolutionJun 04 2019We propose a novel method to up-sample volumetric functions with generative neural networks using several orthogonal passes. Our method decomposes generative problems on Cartesian field functions into multiple smaller sub-problems that can be learned ... More
Advances in Quantum CryptographyJun 04 2019Quantum cryptography is arguably the fastest growing area in quantum information science. Novel theoretical protocols are designed on a regular basis, security proofs are constantly improving, and experiments are gradually moving from proof-of-principle ... More
Geometrical MoM formulation for eigenmode analysisJun 04 2019The resonant frequencies of a structure and the associated field distributions are generally determined by solving a non-linear eigenvalue problem. Using frequency-domain solvers, the response of the structure needs to be evaluated at many different frequencies ... More
Measurement of temperature of a dusty plasma from configurationJun 04 2019A new method called `Configurational Temperature' is introduced in the context of dusty plasma, where the temperature of the dust particles submerged in the plasma can be measured directly from the positional information of the individual dust particles ... More
Generalised Multi-Rate Models for conjugate transfer in heterogeneous materialsJun 04 2019We propose a novel macroscopic model for conjugate heat and mass transfer between a \emph{mobile region}, where advective transport is significant, and a set of \emph{immobile regions} where diffusive transport is dominant. Applying a spatial averaging ... More
Raising the Performance of the Tinker-HP Molecular Modeling Package on Intel's HPC Architectures: a Living Review [Article v1.0]Jun 04 2019This living paper reviews the present High Performance Computing (HPC) capabilities of the Tinker-HP molecular modeling package. We focus here on the reference, double precision, massively parallel molecular dynamics engine present in Tinker-HP and dedicated ... More
Simulations of gas-liquid flow by the Eulerian-Eulerian method: a numerical study of nine casesJun 04 2019In this work, the Eulerian-Eulerian (E-E) method was used to investigate nine classic gas-liquid systems. These test cases were selected from different industries including chemical, nuclear, bio-processing and metallurgical engineering. Although coming ... More
Adaptive activation functions accelerate convergence in deep and physics-informed neural networksJun 04 2019We employ adaptive activation functions for regression in deep and physics-informed neural networks (PINNs) to approximate smooth and discontinuous functions as well as solutions of linear and nonlinear partial differential equations. In particular, we ... More
Surface Fluctuating Hydrodynamics Methods for the Drift-Diffusion Dynamics of Particles and Microstructures within Curved Fluid InterfacesJun 04 2019We introduce fluctuating hydrodynamics approaches on surfaces for capturing the drift-diffusion dynamics of particles and microstructures immersed within curved fluid interfaces of spherical shape. We take into account the interfacial hydrodynamic coupling, ... More
Large-scale Inversion of Subsurface Flow Using Discrete Adjoint MethodJun 03 2019Sensitivity analysis plays an important role in searching for constitutive parameters (e.g. permeability) subsurface flow simulations. The mathematics behind is to solve a dynamic constrained optimization problem. Traditional methods like finite difference ... More
hankel: A Python library for performing simple and accurate Hankel transformationsJun 03 2019This paper presents \textsc{hankel}, a pure-python code for solving Hankel-type integrals and transforms. Such transforms are common in the physical sciences, especially appearing as the radial solution to angularly symmetric Fourier Transforms in arbitrary ... More
Modelling double emulsion formation in planar flow-focusing microchannelsJun 03 2019Double emulsion formation in a hierarchical flow-focusing channel is systematically investigated using a free energy ternary lattice Boltzmann model. A three dimensional formation regime diagram is constructed based on the weber number of the inner phase ... More
A new nonlocal forward model for diffuse optical tomographyJun 03 2019The forward model in diffuse optical tomography (DOT) describes how light propagates through a turbid medium. It is often approximated by a diffusion equation (DE) that is numerically discretized by the classical finite element method (FEM). We propose ... More
Efficient high order accurate staggered semi-implicit discontinuous Galerkin methods for natural convection problemsJun 03 2019We propose a new family of high order staggered semi-implicit discontinuous Galerkin (DG) methods for the simulation of natural convection problems. Assuming small temperature fluctuations, the Boussinesq approximation is valid and the flow can simply ... More
Functional extrapolations to tame unbound anions in density-functional theory calculationsJun 03 2019Standard flavors of density-functional theory (DFT) calculations are known to fail in describing anions, due to large self-interaction errors. The problem may be circumvented by using localized basis sets of reduced size, leaving no variational flexibility ... More
The Fermion Sign Problem in Path Integral Monte Carlo Simulations: Quantum Dots, Ultracold Atoms, and Warm Dense MatterJun 03 2019The ab initio thermodynamic simulation of correlated Fermi systems is of central importance for many applications, such as warm dense matter, electrons in quantum dots, and ultracold atoms. Unfortunately, path integral Monte Carlo (PIMC) simulations of ... More
Symmetry-adapted generation of 3d point sets for the targeted discovery of moleculesJun 02 2019Deep learning has proven to yield fast and accurate predictions of quantum-chemical properties to accelerate the discovery of novel molecules and materials. As an exhaustive exploration of the vast chemical space is still infeasible, we require generative ... More
An acoustic model of a Helmholtz resonator under a grazing turbulent boundary layerJun 02 2019Acoustic models of resonant duct systems with turbulent flow depend on fitted constants based on expensive experimental test series. We introduce a new model of a resonant cavity, flush mounted in a duct or flat plate, under grazing turbulent flow. Based ... More
A hybrid particle volume-of-fluid method for multiphase flows with surface tensionJun 02 2019We present a particle method for estimating the curvature of interfaces and respective surface tension models in volume-of-fluid simulations of multiphase flows. Strings of particles are fitted, through an equilibration process, to the interface reconstruction ... More
High Thermoelectric Performance in Two-Dimensional Tellurium: An Ab Initio StudyJun 01 2019In 2016, bulk tellurium was experimentally observed as a remarkable thermoelectric material. Recently, two-dimensional (2D) tellurium, called tellurene, has been synthesized and has exhibited unexpected electronic properties compared with the 2D MoS$_2$. ... More
Ultralow lattice thermal conductivity and electronic properties of monolayer 1T phase semimetal SiTe2 and SnTe2Jun 01 20192H phase (trigonal prismatic D3h) of layered two-dimensional (2D) transition metal dichalcogenides (TMDs) have attracted a lot of interests due to the superior electronic and optoelectronic properties. However, flexible electronic devices and thermoelectric ... More
Solution of the 3D density-driven groundwater flow problem with uncertain porosity and permeabilityMay 31 2019As groundwater is an essential nutrition and irrigation resource, its pollution may lead to catastrophic consequences. Therefore, accurate modeling of the pollution of the soil and groundwater aquifer is highly important. As a model, we consider a density-driven ... More
A Multi-Resolution 3D-DenseNet for Chemical Shift Prediction in NMR CrystallographyMay 31 2019We have developed a deep learning algorithm for chemical shift prediction for atoms in molecular crystals that utilizes an atom-centered Gaussian density model for the 3D data representation of a molecule. We define multiple channels that describe different ... More
Prediction and optimization of mechanical properties of composites using convolutional neural networksMay 31 2019In this paper, we develop a convolutional neural network model to predict the mechanical properties of a two-dimensional checkerboard composite quantitatively. The checkerboard composite possesses two phases, one phase is soft and ductile while the other ... More
\emph{Ab initio} theory of nitrogen-vacancy center in diamondMay 31 2019Nitrogen-vacancy center in diamond is a solid state defect qubit with favorable coherence time up to room temperature which could be harnessed in several quantum enhanced sensor and quantum communication applications. The quantum control largely depends ... More
Surface tension of supercooled water nanodroplets from computer simulationsMay 31 2019We estimate the liquid-vapour surface tension from simulations of TIP4P/2005 water nanodroplets of size $N$=100 to 2880 molecules over a temperature $T$ range of 180 K to 300 K. We compute the planar surface tension $\gamma_p$, the curvature-dependent ... More
Dynamical disentanglement in an analysis of oscillatory systems: an application to respiratory sinus arrhythmiaMay 31 2019We develop a technique for the multivariate data analysis of perturbed self-sustained oscillators. The approach is based on the reconstruction of the phase dynamics model from observations and on a subsequent exploration of this model. For the system, ... More
Nonlinear phase coupling functions: a numerical studyMay 31 2019Phase reduction is a general tool widely used to describe forced and interacting self-sustained oscillators. Here we explore the phase coupling functions beyond the usual first-order approximation in the strength of the force. Taking the periodically ... More
A Continuum Multi-Disconnection-Mode Model for Grain Boundary MigrationMay 31 2019We study the Grain Boundary (GB) migration based on the underlying disconnection structure and mechanism. Disconnections are line defects that lie solely within a GB and are characterized by both a Burgers vector and a step height, as set by the GB bicrystallography. ... More
Understanding the friction of atomically thin layered materialsMay 31 2019Friction is a ubiquitous phenomenon that greatly affects our everyday lives and is responsible for large amounts of energy loss in industrialised societies. Layered materials such as graphene have interesting frictional properties and are often used as ... More
Coexistence of polar displacements and conduction in doped ferroelectrics: an ab initio comparative studyMay 31 2019Polar metals are rare because free carriers in metals screen electrostatic potential and eliminate internal dipoles. Degenerate doped ferroelectrics may create an approximate polar metallic phase. We use first-principles calculations to investigate $n$-doped ... More
Custom Edge-Element FEM Solver and its Application to Eddy-Current Simulation of Realistic 2M-Element Human Brain PhantomMay 30 2019Extensive research papers of three-dimensional computational techniques are widely used for the investigation of human brain pathophysiology. Eddy current analyzing could provide an indication of conductivity change within a biological body. A significant ... More
Enhanced parallelization of the incremental 4D-Var data assimilation algorithm using the Randomized Incremental Optimal Technique (RIOT)May 30 2019Incremental 4D-Var is a data assimilation algorithm used routinely at operational numerical weather predictions centers worldwide.This paper implements a new method for parallelizing incremental 4D-Var, the Randomized Incremental Optimal Technique (RIOT), ... More
Pass-efficient methods for compression of high-dimensional particle-laden turbulent flow dataMay 30 2019The future of high-performance computing, specifically the next generation of Exascale computers, will presumably see memory capacity and bandwidth fail to keep pace with data generation. Current strategies proposed to address this bottleneck entail the ... More
An efficient method for solving highly oscillatory ordinary differential equations with applications to physical systemsMay 30 2019We present a novel numerical routine (oscode) with a C++ and Python interface for the efficient solution of one-dimensional, second-order, ordinary differential equations with rapidly oscillating solutions. The method is based on a Runge-Kutta-like stepping ... More
Correlation Effects in Quadrupole Insulators: a Quantum Monte Carlo StudyMay 30 2019The quadrupole insulator, a high-order topological insulator, with on-site Hubbard interaction is numerically studied by large-scale projector quantum Monte Carlo (PQMC) simulations. The Green's function formalism is successfully used to characterize ... More