Element Library Research Articles

Resolving the sign conflict problem for hp–hexahedral Nédélec elements with application to eddy current problems

The eddy current approximation of Maxwell’s equations is relevant for Magnetic Induction Tomography (MIT), which is a practical system for the detection of conducting inclusions from measurements of mutual inductance with both industrial and clinical applications. An MIT system produces a conductivity image from the measured fields by solving an inverse problem computationally. This is typically an iterative process, which requires the forward solution of a Maxwell’s equations for the electromagnetic fields in and around conducting bodies at each iteration. As the (conductivity) images are typically described by voxels, a hexahedral finite element grid is preferable for the forward solver. Low order Nédélec (edge element) discretisations are generally applied, but these require dense meshes to ensure that skin effects are properly captured. On the other hand, hp–Nédélec finite elements can ensure the skin effects in conducting components are accurately captured, without the need for dense meshes and, therefore, offer possible advantages for MIT. Unfortunately, the hierarchic nature of hp–Nédélec basis functions introduces edge and face parameterisations leading to sign conflict issues when enforcing tangential continuity between elements. This work describes a procedure for addressing this issue on general conforming hexahedral meshes and an implementation of a hierarchic hp–Nédélec finite element basis within the deal.II finite element library. The resulting software is used to simulate Maxwell forward problems, including those set on multiply connected domains, to demonstrate its potential as an MIT forward solver.

An unsymmetric 8‐node hexahedral element with high distortion tolerance

SummaryAmong all 3D 8‐node hexahedral solid elements in current finite element library, the ‘best’ one can produce good results for bending problems using coarse regular meshes. However, once the mesh is distorted, the accuracy will drop dramatically. And how to solve this problem is still a challenge that remains outstanding. This paper develops an 8‐node, 24‐DOF (three conventional DOFs per node) hexahedral element based on the virtual work principle, in which two different sets of displacement fields are employed simultaneously to formulate an unsymmetric element stiffness matrix. The first set simply utilizes the formulations of the traditional 8‐node trilinear isoparametric element, while the second set mainly employs the analytical trial functions in terms of 3D oblique coordinates (R, S, T). The resulting element, denoted by US‐ATFH8, contains no adjustable factor and can be used for both isotropic and anisotropic cases. Numerical examples show it can strictly pass both the first‐order (constant stress/strain) patch test and the second‐order patch test for pure bending, remove the volume locking, and provide the invariance for coordinate rotation. Especially, it is insensitive to various severe mesh distortions. Copyright © 2016 John Wiley & Sons, Ltd.

Finite elements library in the application to thin-walled shells of rotation

Finite elements library in the application to thin-walled shells of rotation

Dimensions of User Perception of Academic Library as Place

Despite the ongoing discussion on library as place, there has not been a robust framework for understanding the meanings and the dimensions of library as place. The purpose of this study is to identify reliable and meaningful dimensions of academic library as place. The formative elements of academic library as place were elicited in terms of physical setting of place, person, and act. A cross-sectional field study was conducted at a state university in the eastern region of the United States. Principal component analysis identified three dimensions of academic library as place: information and services, reading and study, and relaxation. The conceptualization of academic library as place enables us to confirm constructs, and the established constructs advance theoretical discussions on library as place. The findings of this study are expected to provide empirical evidence of user perception of library as place, thus improving our understanding of users and strategies for the effective design of library space.

A study to evaluate the digitization level of Korean libraries (part I)

Purpose – The purpose of this paper is to discover and enumerate the elements of the digital library and measure how much an individual library was equipped with the characteristics of the digital library accordingly. Design/methodology/approach – For this purpose several steps were taken. First, research on the characteristics and the representative services of the digital library were comprehensively reviewed. Second, examples of the library services that were being considered for the next generation digital library were investigated to compare with the conventional library services. Third, the elements of the conventional and the digital libraries initially extracted were examined by ten experts. These experts were composed of researchers and professors specializing in digital libraries, and career librarians who had worked in the digital library field for at least ten years. The elements were verified through discussions with them. Fourth, 19 university libraries, 16 public libraries, and 17 special libraries were selected in accordance with the verified elements of the conventional and the digital libraries to measure the digitization level of the libraries. Findings – The following is a summary of the evaluation of the first eight evaluation items, which are covered in Part 1 of this study. The remaining five items will be covered in Part 2. First, the digitization level of the acquisition element and classification and cataloguing was significantly high. Second, book collections excluding “digital video,” reference service, library program service, and space service showed significantly conventional characteristics. Third, in the element of circulation services, the item of lending books offline and returning the books scored 92.64 and the item of lending-returning with use of smart devices and social media obtained significantly low scores. Also, the average in using the book return desk for the circulation service was 81.39, much higher than using the automatic book return machine, which scored 18.61, by a wide margin. Fourth, in the element of user services, the digital item of providing support for mobile services related to the library resources demonstrated higher scores than the conventional item, but other items showed more conventional characteristics. In particular, the item of duplication services for material scored 94.99, but other items such as support for publication/bookbinding services using digital publication tools and devices obtained significantly low scores. Originality/value – This study is first study in the world to measure the level of digitization of the library. Therefore, hereafter, each library will be able to measure and determine its digital position based on these elements. Up to now, some research was performed in pursuit of extracting the elements of a library but it has relied solely on literature review. Comprehensive research had never been performed as in this study.

Simulating the Various Subsystems of a Coal Mine

A set of simulation models of various subsystems of a coal mine was developed with the help of a new visual interactive simulation system of technological processes. This paper contains a brief description of this simulation system and its possibilities. The main possibilities provided by the simulation system are: the quick construction of models from library elements, 3D representation, and the communication of models with actual control systems. These simulation models were developed for the simulation of various subsystems of a coal mine: underground conveyor network subsystems, pumping subsystems and coal face subsystems. These simulation models were developed with the goal to be used as a quality and reliability assurance tool for new process control systems in coal mining.

Full Three-Dimensional Multiphysics Model of High-Field Polyhelices Magnets

High field Resistive magnets for static field de- veloped at the Laboratoire National des Champs Magn etiques Intenses (LNCMI) are based on the so-called polyhelix technique. Their design relies on non-linear 3D multi-physic models. As the user demands for higher magnetic field or specific field profile are growing we have to revisit our numerical models. They need to include more physics and more precise geometry. In this context we have rewritten our numerical model in the frame of a collaboration with Institut de Recherche en Math ematique Avanc ee (IRMA). New models have been implemented with the finite element library Feel++. This paper gives a status of these developments and the new features available. Results are presented for a 14 polyhelices insert targeting 36 Tesla in a 34 mm bore.High field Resistive magnets for static field de- veloped at the Laboratoire National des Champs Magn etiques Intenses (LNCMI) are based on the so-called polyhelix technique. Their design relies on non-linear 3D multi-physic models. As the user demands for higher magnetic field or specific field profile are growing we have to revisit our numerical models. They need to include more physics and more precise geometry. In this context we have rewritten our numerical model in the frame of a collaboration with Institut de Recherche en Math ematique Avanc ee (IRMA). New models have been implemented with the finite element library Feel++. This paper gives a status of these developments and the new features available. Results are presented for a 14 polyhelices insert targeting 36 Tesla in a 34 mm bore.

Parallelizing a finite element solver in computational hemodynamics

In the last 20 years, a new approach has emerged to investigate the physiopathology of circulation. By merging medical images with validated numerical models, it is possible to support doctors’ decision-making process. The iCardioCloud project aims at establishing a computational framework to perform a complete patient-specific numerical analysis, specially oriented to aortic diseases (like dissections or aneurysms) and to deliver a compelling synthesis. The project can be considered a pioneering example of a Computer Aided Clinical Trial: i.e., a comprehensive analysis of patients where the level of knowledge extracted by traditional measures and statistics is enhanced through the massive use of numerical modeling. From a computer engineering point of view, iCardioCloud faces multiple challenges. First, the number of problems to solve for each patient is significantly huge – this is typical of computational fluid dynamics (CFD) – and it requires parallel methods. In addition, working in a clinical environment demands efficiency as the timeline requires rapid quantitative answers (as may happen in an emergency scenario). It is therefore mandatory to employ high-end parallel systems, such as large clusters or supercomputers. Here we discuss a parallel implementation of an application within the iCardioCloud project, built with a black-box approach – i.e., by assembling and configuring existing packages and libraries and in particular LifeV, a finite element library developed to solve CFD problems. The goal of this paper is to describe the software architecture underlying LifeV and to assess its performance and the most appropriate parallel paradigm. This paper is an extension of a previous work presented at the PBio 2015 Conference. This revision extends the description of the software architecture and discusses several new serial and parallel optimizations to the application. We discuss the introduction of hybrid parallelism in order to mitigate some performance problems previously experienced.

Parallel subdomain solver strategies for the algebraic additive Schwarz preconditioner

Hybrid domain-decomposition method with two levels of domain partitioning.Solution of the local problem by ShyLU or other parallel approximation techniques.Proposal of an inexact QR factorization to be used within ShyLU.Comparisons of parallel performances between UMFPACK, ShyLU, and inexact QR. Domain-decomposition (DD) methods are used in most, if not all, modern parallel implementations of finite element modeling software. In the solver stage, the algebraic additive Schwarz (AAS) domain-decomposition preconditioner represents a fundamental component and its performance and scalability are key to the overall performance of the solution process. The established approach to construct the preconditioner in a parallel MPI setting is with a 1-to-1 correspondence between the number of MPI processes and the number of AAS subdomains.In this paper, we describe our attempts to extend this paradigm with the possibility to assign more than one MPI process per AAS subdomain, with the goal of improving the overall performance of the AAS preconditioner on supercomputers with multicore nodes.We discuss the implementation of the new AAS preconditioner framework, based on two levels of MPI parallelism, and the performance of different subdomain solver strategies. Finally, we examine the behavior of our novel approach for a series of benchmark problems, performed with the LifeV parallel finite element library.

Reconfigurable HDL Library Development Platform for Arithmetic and Matrix Operations

systems used in real-time applications require design tools that could be costly and may have long verification cycles. Many design tools use predefined libraries and costly IPs during these design and verification cycles, and most of these libraries and IPs are static and difficult to modify. Many design requirements are changed during or after design and verification cycle, and designers need to address these changes and modify the system. This could be more time consuming due to verification cycle and static libraries. It is important to have dynamic libraries that could be modified and reconfigured based on the applications. This work creates reconfigurable arithmetic design blocks that could be used for arithmetic and matrix operations. The reconfigured library development system modifies the required library elements using Perl scripting language and verifies them on-the-fly using MATLAB. The development tool improves design time and reduces the verification process, but the key point is to use a unified design that combines some of the basic operations with more complex operations to reduce area and power consumption. The results indicate that using the reconfigurable development tool reduces verification time and increases the productivity. These libraries include structural Verilog HDL codes, testbench files, and MATLAB script files for local customization. Even though the reconfigurable HDL library is used for FPGA design flow, it could be easily modified for VLSI design flow.

Efficient solution of time‐domain boundary integral equations arising in sound‐hard scattering

SummaryWe consider the efficient numerical solution of the three‐dimensional wave equation with Neumann boundary conditions via time‐domain boundary integral equations. A space‐time Galerkin method with C∞‐smooth, compactly supported basis functions in time and piecewise polynomial basis functions in space is employed. We discuss the structure of the system matrix and its efficient parallel assembly. Different preconditioning strategies for the solution of the arising systems with block Hessenberg matrices are proposed and investigated numerically. Furthermore, a C++ implementation parallelized by OpenMP and MPI in shared and distributed memory, respectively, is presented. The code is part of the boundary element library BEM4I. Results of numerical experiments including convergence and scalability tests up to a thousand cores on a cluster are provided. The presented implementation shows good parallel scalability of the system matrix assembly. Moreover, the proposed algebraic preconditioner in combination with the FGMRES solver leads to a significant reduction of the computational time. Copyright © 2015 John Wiley & Sons, Ltd.

MCNP5 element library least squares method for on-line coal analysis

One of the current methods for the on-line analysis of the coal is the neutron inelastic scattering and thermal-capture analysis (NITA) for non-destructive in situ measurements of the elemental concentration of a bulk sample. A prototype apparatus (including detector, fast neutron source, bulk sample and shielding materials) was simulated by using MCNP5 (Monte Carlo N-Particle) software package. In the material card of MCNP5, the concentration of these elements of the synthetic coal sample was used by taking into consideration of the rates of the lignite coal reserve in Aegean Region of Turkey. The histograms of the relation between number of particles and energy of the gamma were converted to Gaussian distribution by using response functions of the BGO detector. With the separate simulation of MgO, Fe 2 O 3 , CaO, Al 2 O 3 , SiO 2 , Sand C, the element library spectrum was obtained in order to fit the spectrum of synthetic coal sample by using MLR (Multiple Linear Regression) method. By using the relation between the coal sample spectrum and the fitted coal spectrum by MLR, the element library least squares (LLs) method was applied to calculate the elemental contents for the relative coal sample.

An "artificial nose" for the non-invasive diagnosis of anxiety in alveolar breath

Event Abstract Back to Event An "artificial nose" for the non-invasive diagnosis of anxiety in alveolar breath Jessica Fitzgerald1 and Hicham Fenniri2 1 Northeastern University, Bioengineering, United States 2 Northeastern University, Chemical Engineering, United States In recent decades, artificial olfactory devices, known as electronic noses (e-noses), have been developed for disease detection and diagnosis by evaluation of exhaled volatile organic compounds (VOCs), produced from multiple metabolic processes. These devices consist of a cross-reactive sensor array, capable of interacting with multiple vapor analytes, a signal transduction mechanism, and response pattern recognition software. Our working hypothesis is that an increase in production of specific VOCs reflecting compromised metabolic processes found in patients suffering with a range of clinically significant anxiety symptoms could be detected with an e-nose. Such a fingerprint approach may also unveil possible biological pathways relevant to anxiety psychopathology. This paper will present the design and fabrication of our barcoded resin-based (BCR) sensor array and its application for the detection and identification of VOCs. BCRs were prepared from a library of six alkylated styrene monomers, combined in a binary fashion resulting in 63 (2n–1) polymers. The same sub-library was resynthesized by including one of our 10 fluorinated monomer, resulting in 10 additional sub-libraries and a total of 700 copolymers. Upon interaction with an analyte, the vibrational signatures of the polymer array change, resulting in slight but detectable spectral variations for each BCR. The collective response (or analyte-specific patterns) was then be quantified using multivariate data analysis. This platform improves upon existing technologies as it dramatically increases sensitivity and information content using vibrational spectroscopy of a large library of sensory elements (encoded polymers) Our current goal is to optimize a sensor array of BCRs for detecting clinically significant anxiety and stress VOCs with highest disease specificity in exhaled breath. We also plan to optimize (i.e. train) this device for the recognition of analytes of interest that will enhance our ability to render the most accurate anxiety diagnosis. Laser Biomedical Research Center at Massachusetts Institute of Technology; Massachusetts General Hospital Keywords: biosensing, material design, biomedical application, Environmental response Conference: 10th World Biomaterials Congress, Montréal, Canada, 17 May - 22 May, 2016. Presentation Type: Poster Topic: Environmentally sensitive biomaterials Citation: Fitzgerald J and Fenniri H (2016). An "artificial nose" for the non-invasive diagnosis of anxiety in alveolar breath. Front. Bioeng. Biotechnol. Conference Abstract: 10th World Biomaterials Congress. doi: 10.3389/conf.FBIOE.2016.01.02410 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 27 Mar 2016; Published Online: 30 Mar 2016. Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Jessica Fitzgerald Hicham Fenniri Google Jessica Fitzgerald Hicham Fenniri Google Scholar Jessica Fitzgerald Hicham Fenniri PubMed Jessica Fitzgerald Hicham Fenniri Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

A Computational Model of ATV Vehicle for Real-Time Simulation

The paper deals with the description of a computational model of an ATV vehicle in Simulink software. This computational model is created using the basic elements of own library and represents the main driveline parts for the simulation of longitudinal and lateral vehicle dynamics. The article describes the design and function of the computational model and demonstrates the usage of an ATV model in the NI VeriStand software. It can be simulated on the hardware for real-time testing. A simulation of drive is then done to verify the functionality of the assembled model.

Parallel Matrix Multiplication: A Systematic Journey

We expose a systematic approach for developing distributed-memory parallel matrix-matrix multiplication algorithms. The journey starts with a description of how matrices are distributed to meshes of nodes (e.g., MPI processes), relates these distributions to scalable parallel implementation of matrix-vector multiplication and rank-1 update, continues on to reveal a family of matrix-matrix multiplication algorithms that view the nodes as a two-dimensional (2D) mesh, and finishes with extending these 2D algorithms to so-called three-dimensional (3D) algorithms that view the nodes as a 3D mesh. A cost analysis shows that the 3D algorithms can attain the (order of magnitude) lower bound for the cost of communication. The paper introduces a taxonomy for the resulting family of algorithms and explains how all algorithms have merit depending on parameters such as the sizes of the matrices and architecture parameters. The techniques described in this paper are at the heart of the Elemental distributed-memory linear algebra library. Performance results from implementation within and with this library are given on a representative distributed-memory architecture, the IBM Blue Gene/P supercomputer.

GRINS: A Multiphysics Framework Based on the libMesh Finite Element Library

This paper describes a flexible $C++$ software framework, called \tt GRINS, for simulating complex multiphysics systems of partial differential equations using the finite element method. \tt GRINS is designed to facilitate the rapid development and reuse of finite element formulation code as well as other features of complex simulations, including quantity-of-interest functionals, solvers, boundary conditions, initial conditions, and postprocessing. \tt GRINS is built on the \tt FEMSystem framework that is part of the \tt libMesh finite element library. \tt GRINS, through \tt FEMSystem and \tt libMesh, supports a number of contemporary algorithms and computing features including hybrid distributed and shared memory parallelism, parallel adaptive mesh refinement on unstructured grids, goal-oriented refinement driven by dual-weighted residual error estimates in quantities of interest, and adjoint-based parameter sensitivities. \tt GRINS is deployed both as an application binary, allowing immediate use of ex...

The deal.II Library, Version 8.4

AbstractThis paper provides an overview of the new features of the finite element library deal.II version 8.4.

About Rational Phase Design for Open Overhead Transmission Line

In this work we consider optimum configuration of split phase of open overhead line. For analysis of open transmission line efficiency, we used methods of math simulation in evaluation environment MATLAB/Simulink using library elements SimScapeSimPowerSystems. We used geometrical configurations of transmission line towers and characteristics of aluminium-steel conductors as initial data for analysis. We gave recommendations about exploitation of open transmission lines for different voltage types. We found out that the minimum value of full self-compensation length in open transmission line attained with maximum approach of split phase components, keeping in mind mechanical and electrical strength of interphase spacer blocks.

Passive Design Elements in the Architectural Planning of the Public Libraries - Focusing on the Comparison between Site and Building in the G-SEED Pre-certified and Non-certified library -

Purpose: The definition and factors of passive design being the sustainable method of building plan through the preceding research is deducted and the effect of passive design within the public library by applying the deducted factors in the case of built public libraries and further the realization plan of green library aimed to be reviewed in this research. Method: This study is to induce common elements of architecture plan for public library and passive design, and assess application level of re-classified elements of sustainable public library in order to analyze present condition of passive design applied on facilities of public library. First, related laws and planning standards of public library will be reviewed, then the definition of passive design will be considered using advanced research. Through advanced research related to planing elements and passive design for library induced from various plans for library standards, a common ground of induced passive design element will be transformed into assessment items and practices to be analyzed. Result: Libraries which are and are not preliminarily certified by G-SEED will be compared with each other in order to analyze the effects of passive design on G-SEED. Even though various passive elements such as load reduction of air conditioning and energy efficiency exist, there are no assessment tool within G-SEED. The fact that there are only standards for temporary methods such as utilization of construction material and installation of equipment highlights the challenges in quantitative evaluation.

Green Template for Life Cycle Assessment of Buildings Based on Building Information Modeling: Focus on Embodied Environmental Impact

The increased popularity of building information modeling (BIM) for application in the construction of eco-friendly green buildings has given rise to techniques for evaluating green buildings constructed using BIM features. Existing BIM-based green building evaluation techniques mostly rely on externally provided evaluation tools, which pose problems associated with interoperability, including a lack of data compatibility and the amount of time required for format conversion. To overcome these problems, this study sets out to develop a template (the “green template”) for evaluating the embodied environmental impact of using a BIM design tool as part of BIM-based building life-cycle assessment (LCA) technology development. Firstly, the BIM level of detail (LOD) was determined to evaluate the embodied environmental impact, and constructed a database of the impact factors of the embodied environmental impact of the major building materials, thereby adopting an LCA-based approach. The libraries of major building elements were developed by using the established databases and compiled evaluation table of the embodied environmental impact of the building materials. Finally, the green template was developed as an embodied environmental impact evaluation tool and a case study was performed to test its applicability. The results of the green template-based embodied environmental impact evaluation of a test building were validated against those of its actual quantity takeoff (2D takeoff), and its reliability was confirmed by an effective error rate of ≤5%. This study aims to develop a system for assessing the impact of the substances discharged from concrete production process on six environmental impact categories, i.e., global warming (GWP), acidification (AP), eutrophication (EP), abiotic depletion (ADP), ozone depletion (ODP), and photochemical oxidant creation (POCP), using the life a cycle assessment (LCA) method. To achieve this, we proposed an LCA method specifically applicable to concrete and tailored to the Korean concrete industry by adapting the ISO standards to suit the Korean situations.