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A partition of unity approach to fluid mechanics and fluid-structure interactionFeb 16 2019For problems involving large deformations of thin structures, simulating fluid-structure interaction (FSI) remains challenging largely due to the need to balance computational feasibility, efficiency, and solution accuracy. Overlapping domain techniques ... More
A Timer-Augmented Cost Function for Load Balanced DSMCFeb 16 2019Due to a hard dependency between time steps, large-scale simulations of gas using the Direct Simulation Monte Carlo (DSMC) method proceed at the pace of the slowest processor. Scalability is therefore achievable only by ensuring that the work done each ... More
Critical Transitions in Intensive Care Units: A Sepsis Case StudyFeb 15 2019Progression of complex human diseases is associated with transitions across dynamical regimes. These transitions are often phase transitions that generate early-warning signs and provide insights into the underlying disease-driving mechanism(s). In this ... More
Fractional Operators Applied to Geophysical ElectromagneticsFeb 13 2019A growing body of applied mathematics literature in recent years has focussed on the application of fractional calculus to problems of anomalous transport. In these analyses, the anomalous transport (of charge, tracers, fluid, etc.) is presumed attributable ... More
Apollo: A Sequencing-Technology-Independent, Scalable, and Accurate Assembly Polishing AlgorithmFeb 12 2019A large proportion of the basepairs in the long reads that third-generation sequencing technologies produce possess sequencing errors. These errors propagate to the assembly and affect the accuracy of genome analysis. Assembly polishing algorithms minimize ... More
Winning the Big Data Technologies Horizon Prize: Fast and reliable forecasting of electricity grid traffic by identification of recurrent fluctuationsFeb 12 2019This paper provides a description of the approach and methodology I used in winning the European Union Big Data Technologies Horizon Prize on data-driven prediction of electricity grid traffic. The methodology relies on identifying typical short-term ... More
Efficient Computation of High-Order Electromagnetic Field Derivatives for Multiple Design Parameters in FDTDFeb 11 2019This paper introduces a new computational framework to derive electromagnetic field derivatives with respect to multiple design parameters up to any order with the Finite-Difference Time-Domain (FDTD) technique. Specifically, only one FDTD simulation ... More
A model updating procedure to enhance structural analysis in the FE code NOSA-ITACAFeb 11 2019This paper describes the model updating procedure implemented in NOSA-ITACA, a finite-element code for the structural analysis of masonry constructions of historical interest. The procedure, aimed at matching experimental frequencies and mode shapes, ... More
Classifying and analysis of random composites using structural sums feature vectorFeb 08 2019The main goal of this paper is to present the application of structural sums, mathematical objects originating from the computational materials science, in construction of a feature space vector of 2D random composites simulated by distributions of non-overlapping ... More
Macroscopic Lattice Boltzmann Method for Shallow Water Equations (MacLABSWE)Feb 08 2019It is well known that there are two integral steps of streaming and collision in the lattice Boltzmann method (LBM). This concept has been changed by the author's recently proposed macroscopic lattice Boltzmann method (MacLAB) to solve the Navier-Stokes ... More
A robust and non-singular formulation of the boundary integral method for the potential problemFeb 08 2019A non-singular formulation of the boundary integral method (BIM) is presented for the Laplace equation whereby the well-known singularities that arise from the fundamental solution are eliminated analytically. A key advantage of this approach is that ... More
On interface conditions for flows in coupled free-porous mediaFeb 07 2019Many processes in nature (e.g., physical and biogeochemical processes in hyporheic zones, and arterial mass transport) occur near the interface of free-porous media. A firm understanding of these processes needs an accurate prescription of flow dynamics ... More
A Fast Volume Integral Equation Solver with Linear Basis Functions for the Accurate Computation of Electromagnetic Fields in MRIFeb 06 2019Objective: This paper proposes a stable volume integral equation (VIE) solver based on polarization/magnetization currents, for the accurate and efficient computation of the electromagnetic scattering from highly inhomogeneous and high contrast objects. ... More
A Predictor-Corrector Method for Power System Variable Step Numerical SimulationFeb 06 2019This letter proposes a predictor-corrector method to strike a balance between simulation accuracy and efficiency by appropriately tuning the numerical integration step length of a power system time-domain simulation. Numerical tests indicate that, by ... More
A NURBS-based Inverse Analysis for Reconstruction of Nonlinear Deformations of Thin Shell StructuresFeb 05 2019This article presents original work combining a NURBS-based inverse analysis with both kinematic and constitutive nonlinearities to recover the applied loads and deformations of thin shell structures. The inverse formulation is tackled by gradient-based ... More
A nonlinear hyperelasticity model for single layer blue phosphorus based on ab-initio calculationsFeb 04 2019A new hyperelastic membrane material model is proposed for single layer blue phosphorus ($\beta\text{-P}$), also known as blue phosphorene. The model is fully nonlinear and captures the anisotropy of $\beta\text{-P}$ at large strains. The material model ... More
MorteX method for contact along real and embedded surfaces: coupling X-FEM with the Mortar methodFeb 03 2019A method to treat frictional contact problems along embedded surfaces in the finite element framework is developed. Arbitrarily shaped embedded surfaces, cutting through finite element meshes, are handled by the X-FEM. The frictional contact problem is ... More
Stabilized MorteX method for mesh tying along embedded interfacesFeb 03 2019We present a unified framework to tie overlapping meshes in solid mechanics applications. This framework is a combination of the X-FEM method and the mortar method, which uses Lagrange multipliers to fulfill the tying constraints. As known, mixed formulations ... More
Convergence study and optimal weight functions of an explicit particle method for the incompressible Navier--Stokes equationsFeb 03 2019Feb 05 2019To increase the reliability of simulations by particle methods for incompressible viscous flow problems, convergence studies and improvements of accuracy are considered for a fully explicit particle method for incompressible Navier--Stokes equations. ... More
GA-Novo: De Novo Peptide Sequencing via Tandem Mass Spectrometry using Genetic AlgorithmFeb 03 2019Proteomics is the large-scale analysis of the proteins. The common method for identifying proteins and characterising their amino acid sequences is to digest the proteins into peptides, analyse the peptides using mass spectrometry and assign the resulting ... More
Investigating the normal and tangential peeling behaviour of gecko spatulae using a coupled adhesion-friction modelJan 31 2019Feb 05 2019The present work investigates the normal and tangential peeling behaviour of a gecko spatula computationally using a coupled adhesion-friction model. The objective is to explain the strong attachment and easy detachment behaviour of the spatulae as well ... More
Using adjoint CFD to quantify the impact of manufacturing variations on a heavy duty turbine vaneJan 25 2019We consider the evaluation of manufacturing variations to the aerodynamic performace of turbine vanes using the adjoint method. The empirical data is based on 102 white light scans from casted parts. We compare expensive calculations by the finite disfference ... More
Scalable solvers for complex electromagnetics problemsJan 25 2019In this work, we present scalable balancing domain decomposition by constraints methods for linear systems arising from arbitrary order edge finite element discretizations of multi-material and heterogeneous 3D problems. In order to enforce the continuity ... More
Parallelization and scalability analysis of inverse factorization using the Chunks and Tasks programming modelJan 23 2019Jan 24 2019We present three methods for distributed memory parallel inverse factorization of block-sparse Hermitian positive definite matrices. The three methods are a recursive variant of the AINV inverse Cholesky algorithm, iterative refinement, and localized ... More
Differential Privacy for Power Grid ObfuscationJan 21 2019The availability of high-fidelity energy networks brings significant value to academic and commercial research. However, such releases also raise fundamental concerns related to privacy and security as they can reveal sensitive commercial information ... More
FEniCS Mechanics: A Package for Continuum Mechanics SimulationsJan 21 2019FEniCS Mechanics is a Python package to facilitate computational mechanics simulations. The Python library dolfin, from the FEniCS Project, is used to formulate and numerically solve the problem in variational form. The general balance laws from continuum ... More
Fleet Prognosis with Physics-informed Recurrent Neural NetworksJan 16 2019Services and warranties of large fleets of engineering assets is a very profitable business. The success of companies in that area is often related to predictive maintenance driven by advanced analytics. Therefore, accurate modeling, as a way to understand ... More
A Novel Geomechanics Concept for Earthquake Excitations Applied in Time DomainJan 16 2019A novel geomechanics concept is presented for studying the behavior of geomaterials and structures by capturing the underlying dynamics as realistically as possible for earthquake excitation applied in time domain. Enormous amount of damages caused to ... More
A Hybrid High-Order method for finite elastoplastic deformations within a logarithmic strain frameworkJan 14 2019We devise and evaluate numerically a Hybrid High-Order (HHO) method for finite plasticity within a logarithmic strain framework. The HHO method uses as discrete unknowns piecewise polynomials of order $k\ge1$ on the mesh skeleton, together with cell-based ... More
Risk of Cascading Blackouts Given Correlated Component OutagesJan 10 2019Cascading blackouts typically occur when nearly simultaneous outages occur in k out of N components in a power system, triggering subsequent failures that propagate through the network and cause significant load shedding. While large cascades are rare, ... More
Genetic Algorithm based Multi-Objective Optimization of Solidification in Die Casting using Deep Neural Network as Surrogate ModelJan 08 2019In this paper, a novel strategy of multi-objective optimization of die casting is presented. The cooling of molten metal inside the mold is achieved by passing a coolant, typically water through the cooling lines in the die. Depending on the cooling line ... More
Solar-Sail Trajectory Design of Multiple Near Earth Asteroids Exploration Based on Deep Neural NetworkJan 08 2019Jan 16 2019In the preliminary trajectory design of the multi-target rendezvous problem, a model that can quickly estimate the cost of the orbital transfer is essential. The estimation of the transfer time using solar sail between two arbitrary orbits is difficult ... More
A unified framework of epidemic spreading prediction by empirical mode decomposition based ensemble learning techniquesJan 03 2019Jan 07 2019In this paper, a unified susceptible-exposed-infected-susceptible-aware (SEIS-A) framework is proposed to combine epidemic spreading with individuals' on-line self-consultation behaviors. An epidemic spreading prediction model is established based on ... More
Exploring the 3D architectures of deep material network in data-driven multiscale mechanicsJan 02 2019This paper extends the deep material network (DMN) proposed by Liu et al. (2018) to tackle general 3-dimensional (3D) problems with arbitrary material and geometric nonlinearities. The global framework of DMN for mechanistic data-driven multiscale material ... More
Isogeometric Mortar Coupling for Electromagnetic ProblemsDec 27 2018This paper discusses and analyses two domain decomposition approaches for electromagnetic problems that allow the combination of domains discretised by either N\'ed\'elec-type polynomial finite elements or spline-based isogeometric analysis. The first ... More
Incorporating Deformation Energetics in Long-Term Tectonic ModelingDec 24 2018The deformation-related energy budget is usually considered in the simplest form or even completely omitted from the energy balance equation. We derive a full energy balance equation that accounts not only for heat energy but also for mechanical (elastic, ... More
An arbitrary order time-stepping algorithm for tracking particles in inhomogeneous magnetic fieldsDec 19 2018The Lorentz equations describe the motion of electrically charged particles in electric and magnetic fields and are used widely in plasma physics. The most popular numerical algorithm for solving them is the Boris method, a variant of the St\"ormer-Verlet ... More
Proper Generalized Decomposition of Parameterized Electrothermal Problems Discretized by the Finite Integration TechniqueDec 17 2018The proper generalized decomposition is applied to a static electrothermal model subject to uncertainties. A reduced model that circumvents the curse of dimensionality is obtained. The quadratic electrothermal coupling term is non-standard and requires ... More
A global sensitivity analysis and reduced order models for hydraulically-fractured horizontal wellsDec 09 2018We present a systematic global sensitivity analysis using the Sobol method which can be utilized to rank the variables that affect two quantity of interests -- pore pressure depletion and stress change -- around a hydraulically-fractured horizontal well ... More
Critical Time Windows for Renewable Resource Complementarity AssessmentDec 05 2018This paper proposes a systematic framework to assess the complementarity of renewable resources over arbitrary geographical scopes and temporal scales which is particularly well-suited to exploit very large data sets of climatological data. The concept ... More
Complementarity Assessment of South Greenland Katabatic Flows and West Europe Wind RegimesDec 05 2018Current global environmental challenges require firm, yet diverse resolutions in the energy sector. One promising solution consists in harnessing high-quality variable renewable energy (VRE) resources in remote locations, while using transmission links ... More
Numerical modelling of heat transfer and experimental validation in Powder-Bed Fusion with the Virtual Domain ApproximationNov 29 2018Dec 03 2018In contrast with other metal additive manufacturing technologies, powder-bed fusion features very thin layers and rapid solidification rates, leading to long build jobs and a highly localized process. Many efforts are being devoted to accelerate simulation ... More
hynet: An Optimal Power Flow Framework for Hybrid AC/DC Power SystemsNov 26 2018High-voltage direct current (HVDC) systems are increasingly incorporated into today's AC power grids, necessitating optimal power flow (OPF) tools for the analysis, planning, and operation of such hybrid systems. To this end, we introduce hynet, a Python-based ... More
An embedded--hybridized discontinuous Galerkin finite element method for the Stokes equationsNov 22 2018We present and analyze a new embedded--hybridized discontinuous Galerkin finite element method for the Stokes problem. The method has the attractive properties of full hybridized methods, namely a $H({\rm div})$-conforming velocity field, pointwise satisfaction ... More
Re-visiting the single-phase flow model for liquid steel ladle stirred by gasNov 21 2018Ladle stirring is an important step of the steelmaking process to homogenize the temperature and the chemical composition of the liquid steel and to remove inclusions before casting. Gas is injected from the bottom of the bath to induce a turbulent flow ... More
Zeffiro user interface for electromagnetic brain imaging: a GPU accelerated FEM tool for forward and inverse computations in MatlabNov 19 2018Dec 10 2018Background and Objectives This article introduces the Zeffiro interface (ZI) for brain imaging. Zeffiro is Italian for a 'gentle breeze'. ZI is an attempt to provide a simple and accessible and multimodal open source platform for Finite Element Method ... More
Mathematical Modeling of Arterial Blood Pressure Using Photo-Plethysmography Signal in Breath-hold ManeuverNov 14 2018Recent research has shown that each apnea episode results in a significant rise in the beat-to-beat blood pressure and by a drop to the pre-episode levels when patient resumes normal breathing. While the physiological implications of these repetitive ... More
Arterial Blood Pressure Feature Estimation Using PhotoplethysmographyNov 14 2018Continuous and noninvasive monitoring of blood pressure has numerous clinical and fitness applications. Current methods of continuous measurement of blood pressure are either invasive and/or require expensive equipment. Therefore, we investigated a new ... More
Consensus and Sectioning-based ADMM with Norm-1 Regularization for Imaging with a Compressive Reflector AntennaNov 13 2018This paper presents three distributed techniques to find a sparse solution of the underdetermined linear problem $\textbf{g}=\textbf{Hu}$ with a norm-1 regularization, based on the Alternating Direction Method of Multipliers (ADMM). These techniques divide ... More
Prediction of Preliminary Maximum Wing Bending Moments under Discrete GustNov 13 2018Many methodologies have been proposed to quickly identify among a very large number of flight conditions and maneuvers (i.e., steady, quasi-steady and unsteady loads cases) the ones which give the worst values for structural sizing (e.g., bending moments, ... More
AMPS: A Real-time Mesh Cutting Algorithm for Surgical SimulationsNov 01 2018We present the AMPS algorithm, a finite element solution method that combines principal submatrix updates and Schur complement techniques, well-suited for interactive simulations of deformation and cutting of finite element meshes. Our approach features ... More
Stochastic turbulence modeling in RANS simulations via Multilevel Monte CarloNov 01 2018A multilevel Monte Carlo (MLMC) method for quantifying model-form uncertainties associated with the Reynolds-Averaged Navier-Stokes (RANS) simulations is presented. Two, high-dimensional, stochastic extensions of the RANS equations are considered to demonstrate ... More
Exploring Parallel-in-Time Approaches for Eddy Current ProblemsOct 31 2018We consider the usage of parallel-in-time algorithms of the Parareal and multigrid-reduction-in-time (MGRIT) methodologies for the parallel-in-time solution of the eddy current problem. Via application of these methods to a two-dimensional model problem ... More
Leveraging Gaussian Process and Voting-Empowered Many-Objective Evaluation for Fault IdentificationOct 29 2018Using piezoelectric impedance/admittance sensing for structural health monitoring is promising, owing to the simplicity in circuitry design as well as the high-frequency interrogation capability. The actual identification of fault location and severity ... More
Parametric model order reduction and its application to inverse analysis of large nonlinear coupled cardiac problemsOct 29 2018Predictive high-fidelity finite element simulations of human cardiac mechanics co\-mmon\-ly require a large number of structural degrees of freedom. Additionally, these models are often coupled with lumped-parameter models of hemodynamics. High computational ... More
On the ability of discontinuous Galerkin methods to simulate under-resolved turbulent flowsOct 19 2018We investigate the ability of discontinuous Galerkin (DG) methods to simulate under-resolved turbulent flows in large-eddy simulation. The role of the Riemann solver and the subgrid-scale model in the prediction of a variety of flow regimes, including ... More
Development of a Computationally Efficient Fabric Model for Optimization of Gripper Trajectories in Automated Composite DrapingOct 17 2018An automated prepreg fabric draping system is being developed which consists of an array of actuated grippers. It has the ability to pick up a fabric ply and place it onto a double-curved mold surface. A previous research effort based on a nonlinear Finite ... More
Optimizing AIREBO: Navigating the Journey from Complex Legacy Code to High PerformanceOct 16 2018Despite initiatives to improve the quality of scientific codes, there still is a large presence of legacy code. Such code often needs to implement a lot of functionality under time constrains, sacrificing quality. Additionally, quality is rarely improved ... More
Physics-Informed Regularization of Deep Neural NetworksOct 11 2018This paper presents a novel physics-informed regularization method for training of deep neural networks (DNNs). In particular, we focus on the DNN representation for the response of a physical or biological system, for which a set of governing laws are ... More
Probabilistic Safety Analysis using Traffic Microscopic SimulationOct 10 2018Traffic microscopic simulation applications are a common tool in road transportation analysis and several attempts to perform road safety assessments have recently been carried out. However, these approaches often ignore causal relationships between different ... More
Synthesis for Vesicle Traffic SystemsOct 10 2018Vesicle Traffic Systems (VTSs) are the material transport mechanisms among the compartments inside the biological cells. The compartments are viewed as nodes that are labeled with the containing chemicals and the transport channels are similarly viewed ... More
A scalable parallel finite element framework for growing geometries. Application to metal additive manufacturingOct 08 2018Oct 25 2018This work introduces an innovative parallel, fully-distributed finite element framework for growing geometries and its application to metal additive manufacturing. It is well-known that virtual part design and qualification in additive manufacturing requires ... More
A General Sensitivity Analysis Approach for Demand Response OptimizationsOct 07 2018It is well-known that demand response can improve the system efficiency as well as lower consumers' (prosumers') electricity bills. However, it is not clear how we can either qualitatively identify the prosumer with the most impact potential or quantitatively ... More
Integrating CAD and Numerical Analysis: 'Dirty Geometry' handling using the Finite Cell MethodOct 05 2018This paper proposes a computational methodology for the integration of Computer Aided Design (CAD) and the Finite Cell Method (FCM) for models with "dirty geometries". FCM, being a fictitious domain approach based on higher order finite elements, embeds ... More
From geometric design to numerical analysis: A direct approach using the Finite Cell Method on Constructive Solid GeometrySep 28 2018During the last ten years, increasing efforts were made to improve and simplify the process from Computer Aided Design (CAD) modeling to a numerical simulation. It has been shown that the transition from one model to another, i.e. the meshing, is a bottle-neck. ... More
Cancer classification and pathway discovery using non-negative matrix factorizationSep 27 2018Oct 08 2018Extracting genetic information from a full range of sequencing data is important for understanding diseases. We propose a novel method to effectively explore the landscape of genetic mutations and aggregate them to predict cancer type. We used multinomial ... More
A Discontinuous Galerkin Fast Spectral Method for the Full Boltzmann Equation with General Collision KernelsSep 26 2018Nov 02 2018The Boltzmann equation, an integro-differential equation for the molecular distribution function in the physical and velocity phase space, governs the fluid flow behavior at a wide range of physical conditions, including compressible, turbulent, as well ... More
A design-through-analysis approach using the Finite Cell Method (ECCOMAS Congress 2016)Sep 26 2018Modern 3D Computer-Aided-Design (CAD) systems use mainly two types of geometric models. Classically, objects are defined by a Boundary Representation (B-Rep), where only the objects' surfaces with their corresponding edges and nodes are stored. One disadvantage ... More
Coupled Simulation of Transient Heat Flow and Electric Currents in Thin Wires: Application to Bond Wires in Microelectronic Chip PackagingSep 24 2018This work addresses the simulation of heat flow and electric currents in thin wires. An important application is the use of bond wires in microelectronic chip packaging. The heat distribution is modeled by an electrothermal coupled problem, which poses ... More
Automated Netlist Generation for 3D Electrothermal and Electromagnetic Field ProblemsSep 23 2018We present a method for the automatic generation of netlists describing general three-dimensional electrothermal and electromagnetic field problems. Using a pair of structured orthogonal grids as spatial discretisation, a one-to-one correspondence between ... More
Towards a Mini-App for Smoothed Particle Hydrodynamics at ExascaleSep 21 2018The smoothed particle hydrodynamics (SPH) technique is a purely Lagrangian method, used in numerical simulations of fluids in astrophysics and computational fluid dynamics, among many other fields. SPH simulations with detailed physics represent computationally-demanding ... More
Residual stresses in metal deposition modeling: discretizations of higher orderSep 20 2018Sep 25 2018This article addresses the research question if and how the finite cell method, an embedded domain finite element method of high order, may be used in the simulation of metal deposition to harvest its computational efficiency. This application demands ... More
A rule-based method to model myocardial fiber orientation in cardiac biventricular geometries with outflow tractsSep 20 2018Rule-based methods are often used for assigning fiber orientation to cardiac anatomical models. However, existing methods have been developed using data mostly from the left ventricle. As a consequence, fiber information obtained from rule-based methods ... More
Sparse Representations for Uncertainty Quantification of a Coupled Field-Circuit ProblemSep 17 2018We consider a model of an electric circuit, where differential algebraic equations for a circuit part are coupled to partial differential equations for an electromagnetic field part. An uncertainty quantification is performed by changing physical parameters ... More
Deep Co-investment Network Learning for Financial AssetsSep 12 2018Most recent works model the market structure of the stock market as a correlation network of the stocks. They apply pre-defined patterns to extract correlation information from the time series of stocks. Without considering the influences of the evolving ... More
A new exact algorithm for solving single machine scheduling problems with learning effects and deteriorating jobsSep 11 2018In this paper, the single machine scheduling problem with deteriorating jobs and learning effects are considered, which is shown in the previous research that the SDR method no longer provides an optimal solution for the problem. In order to solve the ... More
Visual Attention Model for Cross-sectional Stock Return Prediction and End-to-End Multimodal Market Representation LearningSep 11 2018Technical and fundamental analysis are traditional tools used to analyze individual stocks; however, the finance literature has shown that the price movement of each individual stock correlates heavily with other stocks, especially those within the same ... More
Analysis of Sequence Polymorphism of LINEs and SINEs in Entamoeba histolyticaSep 10 2018The goal of this dissertation is to study the sequence polymorphism in retrotransposable elements of Entamoeba histolytica. The Quasispecies theory, a concept of equilibrium (stationary), has been used to understand the behaviour of these elements. Two ... More
Comparison of Sobol' sequences in financial applicationsSep 10 2018Feb 05 2019Sobol' sequences are widely used for quasi-Monte Carlo methods that arise in financial applications. Sobol' sequences have parameter values called direction numbers, which are freely chosen by the user, so there are several implementations of Sobol' sequence ... More
p-Multigrid matrix-free discontinuous Galerkin solution strategies for the under-resolved simulation of incompressible turbulent flowsSep 04 2018Sep 05 2018In recent years several research efforts focused on the development of high-order discontinuous Galerkin (dG) methods for scale resolving simulations of turbulent flows. Nevertheless, in the context of incompressible flow computations, the computational ... More
Multilevel Monte Carlo for uncertainty quantification in structural engineeringAug 31 2018Practical structural engineering problems often exhibit a significant degree of uncertainty in the material properties being used, the dimensions of the modeled structures, etc. In this paper, we consider a cantilever beam and a beam clamped at both ends, ... More
A concise frictional contact formulation based on surface potentials and isogeometric discretizationAug 30 2018This work presents a concise theoretical and computational framework for the finite element formulation of frictional contact problems with arbitrarily large deformation and sliding. The aim of this work is to extend the contact theory based on surface ... More
Symbolic regression based genetic approximations of the Colebrook equation for flow frictionAug 29 2018Widely used in hydraulics, the Colebrook equation for flow friction relates implicitly to the input parameters; the Reynolds number, and the relative roughness of inner pipe surface, with the output unknown parameter; the flow friction factor. In this ... More
Topology optimization of micro-structured materials featured with the specific mechanical propertiesAug 27 2018Nov 09 2018Micro-structured materials consisting of an array of microstructures are engineered to provide the specific material properties. This present work investigates the design of cellular materials under the framework of level set, so as to optimize the topologies ... More
The Open Energy Modelling Framework (oemof) - A new approach to facilitate open science in energy system modellingAug 24 2018Energy system models have become indispensable tools for planning future energy systems by providing insights into different development trajectories. However, sustainable systems with high shares of renewable energy are characterized by growing cross-sectoral ... More
The XDEM Multi-physics and Multi-scale Simulation Technology: Review on DEM-CFD Coupling, Methodology and Engineering ApplicationsAug 24 2018The XDEM multi-physics and multi-scale simulation platform roots in the Ex- tended Discrete Element Method (XDEM) and is being developed at the In- stitute of Computational Engineering at the University of Luxembourg. The platform is an advanced multi- ... More
An iterative generalized Golub-Kahan algorithm for problems in structural mechanicsAug 23 2018This paper studies the Craig variant of the Golub-Kahan bidiagonalization algorithm as an iterative solver for linear systems with saddle point structure. Such symmetric indefinite systems in 2x2 block form arise in many applications, but standard iterative ... More
Dynamic simulations in SixTrackAug 19 2018The DYNK module allows element settings in SixTrack to be changed on a turn-by-turn basis. This document contains a technical description of the DYNK module in SixTrack. It is mainly intended for a developer or advanced user who wants to modify the DYNK ... More
Maximising Throughput in a Complex Coal Export SystemAug 18 2018Aug 22 2018The Port of Newcastle features three coal export terminals, operating primarily in cargo assembly mode, that share a rail network on their inbound side, and a channel on their outbound side. Maximising throughput at a single coal terminal, taking into ... More
Choosing the optimal multi-point iterative method for the Colebrook flow friction equation -- Numerical validationAug 10 2018The Colebrook equation $\zeta$ is implicitly given in respect to the unknown flow friction factor $\lambda$; $\lambda=\zeta(Re,\epsilon^*,\lambda)$ which cannot be expressed explicitly in exact way without simplifications and use of approximate calculus. ... More
Fast computation of the principal components of genotype matrices in JuliaAug 09 2018Finding the largest few principal components of a matrix of genetic data is a common task in genome-wide association studies (GWASs), both for dimensionality reduction and for identifying unwanted factors of variation. We describe a simple random matrix ... More
Blockchain Queueing TheoryAug 06 2018Sep 30 2018Blockchain has many benefits including decentralization, availability, persistency, consistency, anonymity, auditability and accountability, and it also covers a wide spectrum of applications ranging from cryptocurrency, financial services, reputation ... More
Advanced iterative procedures for solving the implicit Colebrook equation for fluid flow frictionJul 26 2018Empirical Colebrook equation from 1939 is still accepted as an informal standard to calculate friction factor during the turbulent flow through pipes from smooth with almost negligible relative roughness to the very rough inner surface. The Colebrook ... More
Uncertainty quantification for an optical grating coupler with an adjoint-based Leja adaptive collocation methodJul 19 2018This paper addresses uncertainties arising in the nano-scale fabrication of optical devices. The stochastic collocation method is used to propagate uncertainties in material and geometry to the scattering parameters of the system. A dimension-adaptive ... More
A stabilized cut discontinuous Galerkin framework: II. Hyperbolic problemsJul 15 2018We present the second part of a stabilized cut discontinuous Galerkin (cutDG) framework initiated in [1] and develop a novel cutDG method for scalar hyperbolic problems. The domain of interest is embedded into a structured, unfitted background mesh in ... More
Accessible computational materials design with high fidelity and high throughputJul 15 2018Despite multiple successful applications of high-throughput computational materials design from first principles, there is a number of factors that inhibit its future adoption. Of particular importance are limited ability to provide high fidelity in a ... More
One-Log Call Iterative Solution of the Colebrook Equation for Flow Friction Based on Pade PolynomialsJul 12 2018The 80 year-old empirical Colebrook function, widely used as an informal standard for hydraulic resistance, relates implicitly the unknown flow friction factor, with the known Reynolds number and the known relative roughness of a pipe inner surface. It ... More
A Numerical Comparison of an Isogeometric and a Classical Higher-Order Approach to the Electric Field Integral EquationJul 10 2018In this paper, we advocate a novel spline-based isogeometric approach for boundary elements and its efficient implementation. We compare solutions obtained by both an isogeometric approach, and a classical parametric higher-order approach via Raviart-Thomas ... More
Meshless Methods for Large Deformation ElastodynamicsJul 03 2018Jul 05 2018Meshless methods are a promising candidate to reliably simulate materials undergoing large deformations. Unlike mesh based methods like the FEM, meshless methods are not limited in the amount of deformation they can reproduce since there are no mesh regularity ... More
Personalized Radiotherapy Design for Glioblastoma Using Mathematical Models, Multimodal Scans and Bayesian InferenceJul 02 2018Nov 15 2018Glioblastoma is a highly invasive brain tumor, whose cells infiltrate surrounding normal brain tissue beyond the lesion outlines visible in the current medical scans. These infiltrative cells are treated mainly by radiotherapy. Existing radiotherapy plans ... More