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    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>Demonstrating a Linked Data Platform for Finite Element Biosimulations of Cochlear Mechanics</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Muntazir Mehdi</string-name>
          <xref ref-type="aff" rid="aff2">2</xref>
          <xref ref-type="aff" rid="aff3">3</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Yasar Khan</string-name>
          <xref ref-type="aff" rid="aff2">2</xref>
          <xref ref-type="aff" rid="aff3">3</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Andre Freitas</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff3">3</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Joao Jares</string-name>
          <xref ref-type="aff" rid="aff2">2</xref>
          <xref ref-type="aff" rid="aff3">3</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Panagiotis Hasapis</string-name>
          <xref ref-type="aff" rid="aff1">1</xref>
          <xref ref-type="aff" rid="aff3">3</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Ratnesh Sahay</string-name>
          <xref ref-type="aff" rid="aff2">2</xref>
          <xref ref-type="aff" rid="aff3">3</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Computer Science Department, University of Passau</institution>
          ,
          <country country="DE">Germany</country>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>INTRASOFT International</institution>
          ,
          <country country="LU">Luxembourg</country>
        </aff>
        <aff id="aff2">
          <label>2</label>
          <institution>Insight Centre for Data Analytics</institution>
          ,
          <addr-line>NUI Galway</addr-line>
          ,
          <country country="IE">Ireland</country>
        </aff>
        <aff id="aff3">
          <label>3</label>
          <institution>Introduction &amp;</institution>
        </aff>
      </contrib-group>
      <abstract>
        <p>Biosimulations employ Finite Element Method (FEM) to simulate complex biological systems in order to understand different aspects of human organs. The applications of FEM biosimulations range from human ear cochlear mechanics, cardiovascular, to neurovascular research. Performing these large Finite Element (FE) simulations, comparison and analysis of multiple simulation experiment results, and visualization of large FEM numerical data is a time consuming hectic job for domain experts - mainly because simulations are performed in an isolated environment. In this paper, we demonstrate a linked data platform to dispatch simulations on biosimulation models for the inner-ear (cochlear) mechanics in an integrated non-isolated environment.</p>
      </abstract>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>Motivation</title>
      <p>
        The creation of computational biosimulation models plays a fundamental role in the
scientific practice with regard to the understanding of biological systems [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ]. Finite
Element Method (FEM) provides a mathematical and computational framework to simulate
dynamic biological systems, with applications ranging from human ear,
cardiovascular, to neurovascular research. A FE biosimulation depends on the creation of models
which span across multiple, complex and semantically incompatible domains, such as
biological models, geometrical structures and mathematical-physical models.
      </p>
      <p>
        The cochlea (human inner-ear) represents a complex bio-mechanical device and
a complete understanding of its behaviour is difficult. The creation of cochlea model,
to perform biosimulation experiments depend on integration of heterogeneous models
at different scales (e.g. basilar membrane, organ of corti and outer hair cells) and
theoretical domains (e.g. mechanical, geometrical, and electrical) [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ]. In our observation,
performing simulations on a cochlea model is a time-consuming process, mainly because
of different and often heterogeneous mathematical parameters. The growing complexity
and sophistication of biosimulation models, the effort associated with the creation and
analysis of a FE model can grow unmanageable. Due to lack of a well-integrated data
infrastructure, the steps involved in the execution and comparative evaluation of a
largescale finite element simulation such as preparing input numerical parameters, solver
usages, visualisation and result/output interpretation are time consuming and often
performed in isolated environments.
      </p>
      <p>In this paper we present a Linked Data platform aiming to improve the automation
in integration, interpretation and visualisation of biosimulations models for inner-ear
(cochlea) mechanics. The aim of the proposed platform is to facilitate the reproducibility,
reuse, interoperability and automation of FE models with the support of Semantic
Web standards and tools. Specifically, to support a domain-expert in performing all
isolated tasks of a simulation experiment using a simplified, integrated platform. As
most of FE data is numerical, this work explores mechanisms to bridge (link) data
on the numerical to the conceptual (ontology) level, facilitating and automating the
interpretation of the simulation results. To the best of our knowledge, the proposed linked
data platform is a first unified infrastructure that bring together numerical parameters,
models, terminologies, storage, querying, visualisation and analysis to conduct a finite
element biosimulaion.</p>
      <p>
        Our work is motivated by the need of clinical organisations and labs conducting
biosimulation experiments to understand the exact pathophysiological consequences and
risk factors of hearing impairment in humans. Our work is conducted in context of the
SIFEM EU project1, which aims at developing an open-source linked data platform for
Finite Element multi-scale modelling and biosimulation of the sensorineural hearing
loss.
SIFEM Infrastructure: In order to achieve the aim and objectives of the proposed
Linked Data Platform, we define a SIFEM Architecture as depicted in Figure 1. The
proposed linked data platform addresses following challenges in integrating, interpreting
and visualising numerical parameters along with simulation results: (i) resolve different
data formats (e.g, .dat, unv, .pak, etc.) by transforming them into standard RDF format;
(ii) resolve heterogeneous terminologies originating from multiple disjoint domains
by building a conceptual model using multiple reference ontologies from biological,
geometrical, mathematical, and physical domains; (iii) providing links across input
parameters/values and simulations results in-order to reuse relevant data analysis in
future experiments; and (iv) visualisation and data analysis over FE simulation results.
Further information about SIFEM conceptual model can be found in [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ].
1 http://www.sifem-project.eu/
      </p>
    </sec>
    <sec id="sec-2">
      <title>SIFEM Platform</title>
      <p>The SIFEM platform is built as a Web application 2, following the SIFEM architecture.
The main screenshot of the platform is depicted in Figure 2, where multiple sub-windows,
corresponding to different tasks of a bio-simulation experiment can be seen. Each
individual sub-window is invoked using a SIFEM Action Console, given in Figure 3. The
SIFEM platform can be accessed on http://213.249.38.66:7071/Sifem/ 3.
The user provides various inputs related to the simulation experiments 4 through the
action console, such as boundary conditions and parameters (damping factor, fluid
viscosity etc.) and mesh properties (box model, cochlear model etc.). The user then invokes
various services, such as FEM solver, RDFization etc. which process the input data and
generates simulation results. The inputs and outputs are RDFized to achieve
interoperability among different solvers. The services available through the action console are
briefly discussed below (From left-to-right, as shown in Figure 3, e.g. Material Properties
is the left most action button, while User Profile is the right most action button):
2 The initial version of the platform is released as an open source version, the source code of
beta-version 1 is available at: https://goo.gl/sxePc8
3 SIFEM Platform User-Manual on https://goo.gl/hbTYZt
4 A video, depicting a sample simulation experiment of the running SIFEM platform can be
found on https://goo.gl/wDC0am
Mesh Setup: The mesh setup menu allows the user to specify the mesh file as input for
the FEM solver.</p>
      <p>Visualization: The Visualisation menu visualises the graphs plotted using the
simulation experiment data. Both 2D and 3D graphs are generated using the simulation
data.</p>
      <p>Knowledge Base Editor: The knowledge base editor menu opens a new dialog that
allows the user to manually enter data in the form of RDF triples into the knowledge
base.</p>
      <p>Rules Editor and Validator: The Rule Editor and Validator menu is used by the
experimenter to define and validate rules before running a simulation to validate the results
of the simulation automatically. For example, the experimenter can specify a rule,
saying the value of frequency should not be greater than 20 kHz as it is maximum
frequency limit a human ear can hear. While running the simulation, results will be
validated by the rule validator based on the rules specified by the experimenter.
SPARQL Editor: The SPARQL editor menu opens a new dialog that allows the user to
create SPARQL query and run the query to receive results from the knowledge base.
Transformations: The transformation menu lets the user to select the type of
transformation for the selected solver, such as displacement, greenwood etc.</p>
      <p>User Profile: The user profile menu shows the profile of the currently logged in user.
Summary: In this paper, we demonstrate a linked data platform that improves
integration, reproducibility and automation of Finite Element (FE) biosimulations. The proposed
platform is developed using SIFEM architecture that combines together numerical
parameters, models, terminologies, storage, querying, visualisation and analysis to conduct
a FE biosimulation experiment. The platform is developed on a use-case to understand
the exact pathophysiological consequences and risk factors of hearing impairment in
humans. The experimental biosimulation data and models are from scientific and clinical
studies about the structure-function relationship in normal and pathological cochlear. A
survey evaluating the qualitative attributes of SIFEM platform has been conducted, the
complete results of the survey can be seen on https://goo.gl/PSvvLY.
ACKNOWLEDGEMENTS: This publication has emanated from research supported in part by
the research grant from Science Foundation Ireland (SFI) under Grant Number SFI/12/RC/2289
and EU project SIFEM (contract Number 600933).</p>
    </sec>
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