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  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>Visual Analysis of a Research Group's Performance thanks to Linked Open Data</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Oscar Pen~a</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Jon Lazaro</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Aitor Almeida</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Pablo Ordun~a</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Unai Aguilera</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Diego Lopez-de-Ipin~a</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Deusto Institute of Technology - DeustoTech, University of Deusto Avda. Universidades 24</institution>
          ,
          <addr-line>48007, Bilbao</addr-line>
          ,
          <country country="ES">Spain</country>
        </aff>
      </contrib-group>
      <abstract>
        <p>Managing data within a research unit is not a trivial task due to the high number of entities to deal with: projects, researchers, publications, attended events, etc. When all these data are exposed on a public website, the need to have it updated is fundamental to avoid getting an incorrect impression of the group's performance. As research centres websites are usually quite static, external documents are generated by managers, resulting in data redundancy and out-of-date records. In this paper, we show our e orts to manage all these data using Labman, a web framework that deals with all the data, links entities and publishes them as Linked Open Data, allowing to get insightful information about the group's productivity using visual analytics and interactive charts.</p>
      </abstract>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>Introduction</title>
      <p>Managing metadata e ectively within a research unit is an ambitious goal, as
information systems need to deal with the relationships among the entities
that form the organization's data model: projects, publications, researchers and
project managers, topics, etc. Most research groups expose their data using a
well known Content Management System (CMS) such as Joomla!1, WordPress2
or Drupal3. Nonetheless, in order to extract valuable knowledge from all those
data, external tools are needed to perform data analysis techniques. Exporting
data in easy to handle formats from the CMS's databases usually leads to the
creation of external documents which store data that will later be analysed.</p>
      <p>This common situation has the following drawbacks: external documents
(e.g., CSV, spreadsheets, text les, etc.) cause data redundancy, resulting in
data quality, completeness and updating issues. This gets worse when
investigators have their own personal pages (outside the system) where they show the
achievements of their researching careers, funding data is managed by the
accounting department and so on. When data needs to be updated in di erent</p>
      <sec id="sec-1-1">
        <title>1 http://joomla.org/</title>
      </sec>
      <sec id="sec-1-2">
        <title>2 http://wordpress.com/</title>
      </sec>
      <sec id="sec-1-3">
        <title>3 http://drupal.org/</title>
        <p>systems, the expected outcome is that at some point data is going to be
outdated somewhere, thus leading to errors when trying to get the whole picture of
a research unit's performance.</p>
        <p>
          Therefore, we present our e orts towards managing our research group's data,
avoiding redundancy, improving quality and sharing the data in a standardized
and interoperable way. Labman (Laboratory Management) is presented as a
tool to manage all these data, publishing them as Linked Open Data. Linked
Data allows to uniquely identify each entity instance with an URI, encouraging
the creation of relationships among instances in order to discover patterns and
insights in a dataset. Labman is a web application developed in Python using
Django4, and is Open Sourced on its Github's repository page5, where it can be
downloaded and contributed to. Labman is developed to substitute a previous
Joomla! plugin developed at the research unit to publish publication data as
RDF [
          <xref ref-type="bibr" rid="ref1">1</xref>
          ], thus overtaking the previously mentioned limitations.
        </p>
        <p>This paper is structure as follows: First, we discuss similar e orts in section
2. Next, section 3 elaborates on the bene ts of publishing information as Linked
Data. Section 4 exhibits how patterns and knowledge can be extracted thanks
to visualization techniques. Finally, conclusions and future work are addressed
in section 5.
2</p>
      </sec>
    </sec>
    <sec id="sec-2">
      <title>Related work</title>
      <p>Even though some plugins have been developed to publish data stored within
CMS systems as RDF (Resource Description Framework) les and RDFa
metadata6, they lack the ability to both make it accesible through a SPARQL
endpoint (not allowing complex queries from external entities) and the advantages
of publishing them following the Linked Data principles.</p>
      <p>
        Research metadata visualization has also been studied by works such as [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ]
and [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ], where authors use techniques from the visual analytics area to extract
insights of research evolution in the studied cases. However, these works do not
take the interlinking advantages of semantic descriptions, working with static
dumps of database data.
      </p>
      <p>
        The e orts of iMinds Multimedia Lab [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ] demonstrates the potential insights
that visual analytics provide when analysing research status on a country-level
basis (i.e., applied to the whole research system of Belgium), publishing more
than 400 million triples. Whereas users can get a full picture of the nation's
research status, it does not substitute the information systems of the individual
research centres.
      </p>
      <p>ResearchGate7 is a social networking site for scientist and researchers to
share their work, providing metrics ands statistics to show their performance.</p>
      <sec id="sec-2-1">
        <title>4 https://djangoproject.com/</title>
      </sec>
      <sec id="sec-2-2">
        <title>5 https://github.com/OscarPDR/labman_ud</title>
      </sec>
      <sec id="sec-2-3">
        <title>6 http://rdfa.info/</title>
      </sec>
      <sec id="sec-2-4">
        <title>7 http://www.researchgate.net/</title>
        <p>The focus is set on individuals to promote their work, whereas our proposal
focuses on providing information on a research unit level basis.</p>
        <p>Linked Universities, according to the de nition on their website8 \is an
alliance of european universities engaged into exposing their public data as linked
data". Specially focused on sharing educational data (e.g., courses, educational
materials, teachers information, etc.), it also promotes the publishing of research
and publication-related data. Linked Universities highlights the needs to have
common shared vocabularies and tools to allow interoperability among how
people access information about di erent institutions. Labman takes the
recommendations from this alliance at its own core to avoid loosing the bene ts provided
by shared standards and vocabularies.</p>
        <p>Finally, VIVO9 is a huge project that provides an Open Source semantic
web application to enable the discovery of researchers across institutions. VIVO
allows any university to manage their data, and publish it using the VIVO
ontology. VIVO is specially used among American universities.
3</p>
      </sec>
    </sec>
    <sec id="sec-3">
      <title>Publication of resources as Linked Open Data</title>
      <p>
        Linked Data (LD) is a series of principles and best practices to publish data in
a structured way, encouraged by Tim Berners-Lee and the W3C [
        <xref ref-type="bibr" rid="ref5">5</xref>
        ]. LD is built
over web standards such as HTTP, RDF and URIs, in order to provide
information in a machine readable format. Every resource has its own URI, becoming
a unique identi er for the data entity through all the system, thus avoiding
data redundancy. Should somebody decide to extend the description of a given
resource in its own dataset, both resources can be linked using the rdfs:seeAlso
property, addressing that both resources refer to the same conceptual entity. The
use of rdfs:seeAlso over owl:sameAs is preferred due to the semantic meaning
di erence between these properties: the former links two resources which refer
to the same entity (maybe through di erent vocabularies), whereas the later
connects two resources described in quite a similar way in di erent datasets.
      </p>
      <p>The implicit linkage between resources in LD also allows to interconnect
resources among them, e.g., a research project with the descriptions of people
working on it and the related articles published as the outcomes of the study.
Although this feature can also be achieved through plain relational database
models, LD allows to connect references to external datasets, so complex queries
can be performed in SPARQL, avoiding the potential headaches of joining
consecutive SQL sentences and the need of having all the data in our system.</p>
      <p>The \Open" term in Linked Open Data indicates that is freely available to
everyone to use and republish data as they wish, without copyright and patent
restrictions. All the information published on Labman is of public domain by
default, making it freely consumable through its SPARQL endpoint. However,
there is an option to mark a certain's project funding as private. If marked, this
nancial information will be used for the generation of top level visualizations</p>
      <sec id="sec-3-1">
        <title>8 http://linkeduniversities.org/</title>
      </sec>
      <sec id="sec-3-2">
        <title>9 http://www.vivoweb.org/</title>
        <p>(those which give a full view of the unit's performance), but no funding charts
will be rendered for that speci c project and the funding amounts triples will
not be generated.
3.1</p>
        <sec id="sec-3-2-1">
          <title>Managing data within Labman</title>
          <p>
            To encourage the adoption of Labman among the Semantic Web community,
we have used well known vocabularies to describe the data of the di erent
entities in our data model. The Semantic Web for Research Communities (SWRC)
[
            <xref ref-type="bibr" rid="ref6">6</xref>
            ] ontology has been extended to provide nancial information about research
projects, together with some missing properties to link resources in our model.
SWRC-FE (SWRC Funding Extension) is available for any semantic
enthusiast to be used in their descriptions10. Researchers are mainly described using
FOAF11, while publications are de ned thanks to the complete BIBO ontology12.
Actually research topics are published using the Modular Uni ed Tagging
Ontology (MUTO)13, but we are considering to reference external topic datasets in
the near future.
          </p>
          <p>Labman stores data both in a relational database and as RDF triples (the
relational database is used to increase performance and to allow non-semantic
erudits to work with relational dumps). When an instance of any model is saved
in Labman, a call is triggered to publish the instance and its attributes as RDF,
generating or updating the referenced resource and its associated triples thanks
to the rules of mapping speci ed for each model. Those triples are loaded into
an Open Link Virtuoso14 instance to be later on accessible through the
dedicated SPARQL endpoint15. Semantics can be enabled/disabled on demand for
a full deploy of Labman through general settings (useful when installing a local
instance of Labman to get a taste of the system and easing the transition from
a legacy relational database model). A single management command allows to
make a full dump of the relational database and publish it as RDF triples. The
list of available extra commands within labman can be consulted through the
{help modi er of Django's manage.py command line feature.</p>
          <p>To help with publications data adquisition, a Zotero16 parser has been
developed in order to extract all publication-related data and import it in Labman's
system, publishing it as Linked Open Data using the previous described
ontologies. Thanks to Zotero and the browser plugins, all metadata regarding a
publication is extracted from well known publication indexing databases such as
Web of Science, CiteSeer, Springer, Elsevier and so forth.</p>
          <p>As the same authors may appear under slightly di erent names on di erent
sites, Labman implements an author alias algorithm to perform term
disam10 http://www.morelab.deusto.es/ontologies/swrcfe
11 http://www.foaf-project.org/
12 http://bibliontology.com/
13 http://muto.socialtagging.org/core/v1.html
14 http://virtuoso.openlinksw.com/
15 http://www.morelab.deusto.es/labman/sparql
16 https://www.zotero.org/
biguation and apply the corresponding substitutions. This simple algorithm uses
Python's di ib library17 to compare strings (e.g., author full names), taking as
input string pairs of all the author names present in Labman, and returning a
similarity ratio between them (as shown in table 1. If the ratio is greater than the
given threshold, both strings are sent to Labman's administrators for
dissambiguation checking. If the match is approved, the incorrect author name from
the pair is assigned as an alias of the valid name. A periodic background task
unlinks all the referenced triples to the invalid alias, and assigns them to the
correct author resource.</p>
        </sec>
      </sec>
    </sec>
    <sec id="sec-4">
      <title>Understanding research data through visualizations</title>
      <p>The adage \A picture is worth a thousand words" ts perfectly when visualizing
research related info, as the huge amounts of data related to projects, funding
agencies, organizations, researchers and so forth makes them perfect candidates
to be rendered using visual representations, instead of displaying all the
information in text form without highlighting underlying connections.</p>
      <p>In order to access and interact with the visualizations through any web
browser, web graphics libraries such as Google Charts18, d3js19 and sigma.js20
have been used. Charts and graphs are rendered on the screen using JavaScript,
with data extracted from Labman using Python.</p>
      <p>Due to the interlinked nature of Linked Open Data, most visualizations
showing linked entities are rendered as graphs and linked nodes. Visualizations are
available on the Charts section21 and on the extended information subsections
of the webpage.
4.1</p>
      <sec id="sec-4-1">
        <title>Funding</title>
        <p>Project managers and principal investigators usually depend on funds to continue
their research work. In a transparency e ort, Labman allows to consult how much
money is gathered from public entities, as displayed in gure 1.
17 https://docs.python.org/2/library/difflib.html
18 https://developers.google.com/chart/
19 http://d3js.org/
20 http://sigmajs.org/
21 http://www.morelab.deusto.es/labman/charts/</p>
        <p>Funds are provided by public administrations and organizations, usually
under a named funding call. Labman also takes this information into account and
allows to compare di erent calls' performances. For example, the principal
investigator can view historical records from european FP7 and spanish INNPACTO
funding calls to design the new budget strategy for the forthcoming years.
Geographical scopes can be de ned and related to Geoname's22 feature classes, to
classify funding call levels according to their e ect area.
4.2</p>
      </sec>
      <sec id="sec-4-2">
        <title>Project and publication collaborations</title>
        <p>Research would not be possible without the collaborations of di erent researchers
working together to generate new knowledge. Being able to detect research
networks is a fundamental insight to have always present, together with the
communities of practice our unit takes part in and the evolution and the interactions
with members of external disciplines.</p>
        <p>
          In gure 2, a force directed graph is selected to represent project
collaborations present in the system. When hovering over an element, only the node's
community is visible, allowing to consult who each person is related with. Node's
size is calculated using Eigenvector centrality, a value which increases if the
connection with other central nodes of the graph is relevant, and the color of each
node indicates the community it belongs to. Community belonging is calculated
using modularity, and a di erent color does not mean they do not work for the
same organization, but that their connections make them beloging to a di erent
group of interconnected people. The calculations for generating these graphs are
further explained in [
          <xref ref-type="bibr" rid="ref7">7</xref>
          ]. Link weights take into account the strenght of the
collaboration. For example, in projects, the more time spent working with a colleague,
the stronger the connection will be, whereas the number of co-authored
publications is a strong indicator of the preferences of publishing together.
Collaboration edges create di erent triples, more accurate than the foaf:knows relation
to analyse the relationship between two researchers.
22 http://www.geonames.org/
        </p>
        <p>
          Figure 3 shows the egonetwork [
          <xref ref-type="bibr" rid="ref8">8</xref>
          ] of one of our researcher's (highlighted
with a dotted circle), which represents the actual publication collaborations the
researcher has with other members of the system. The stronger the links between
two authors, the more publications they have produced together.
        </p>
        <p>Sometimes relations between researchers are not explicit (e.g., two researchers
have not worked together in a project or co-authored the same paper, but both
of them work in the same knowledge area). In order to identify these relations
we have implemented a similarity coe cient using the tags of the papers of each
researcher. To ascertain the similarity of one researcher with another we have
devised the following formula:
coef = jB \ Aj</p>
        <p>A
j j</p>
        <p>Where A is the set of tags belonging to the base researcher and B is the
set of tags belonging to the researcher which we want to compare the base
researcher with. It must be taken into account that this similarity coe cient
is not symmetrical. The reason is the topic similarity for a given researcher is
considered within the whole of its tags, without taking into account the whole
topics a related researcher works in. This situation is common for novel PhD
students with a few published articles, who share all their topics with their
advisors (due to their co-authorship), but senior researchers will have a broader
set of areas they have worked on because of ther large research trajectory.
Together with the identi cation of research networks, knowing which topics those
networks and the involved researchers are working in is fundamental to
understand the most relevant areas the group is focusing on. Projects and
publications are tagged with concepts in Labman, published as dc:subject triples using
the muto:Tag ontology. The rst obvious visual representation is to generate
weighted lists (also known as tag or word clouds) of the topics used by a
researcher. Figure 5 displays the topics used by one of our researchers, being the
size of the tag representative of its weight (i.e., the bigger the tag, the more
proli c in that area).</p>
        <p>
          Research topic evolutions are also a good indicator to detect which areas
the group is focused on. The historical evolution helps understanding which
topics are no longer hot amongst researchers, and which topics have died to
evolve into new research areas (e.g., from Ubiquitous computing to Internet of
Things to Weareable computing ). ArnetMiner [
          <xref ref-type="bibr" rid="ref9">9</xref>
          ] generates similar visualizations
using automatically extracted metadata from the papers it nds for a researcher.
However, many papers are not gathered, making those visualizations not to show
the real status of the research.
        </p>
        <p>Eventually, establishing a robust taxonomy of topics leads to the identi
cation of interest groups and expertise hubs around topics, allowing to relate
researchers, projects and publications automatically where no previous obvious
hints were available to connect them. Describing resources using shared
vocabularies and connecting to external knowledge datasets allows to create these links
in a global space, opening new doors to knowledge discovery thanks to the use
of Linked Data principles.
5</p>
      </sec>
    </sec>
    <sec id="sec-5">
      <title>Conclusions and future work</title>
      <p>Using dynamic visualizations of research information published as Linked Open
Data, helps end-users (i.e., those consulting the information either from the
research centre or visitors) to discover real connections between its members
and the di erent entities modelled in the system. Visually representing which
topics the researchers work on, who can be consulted about a certain area, and
the historical collaborations within the group members can be of great help to
guide the development of new project proposals, discover non-obvious potentials
and address the key entities.</p>
      <p>As future work, we will continue working on the generation of new
visualizations to provide opportunities to improve the performance and strategic vision of
a research centre. There is a strong continuous commitment to connect entities
with external datasets, in order to evolve from a four-star to a full Linked Open
Data data space, making Labman able to answer complex queries with data
not present in our system, including other descriptions to the same resources
available on the Web of Data. Finally, a ne detail level when well de ning and
describing topics will allow for deeper analysis of data, taking into consideration
the evolution of topics through time and how research areas are hierarquically
structured. Actually, topics are cleaned and reviewed automatically on a regular
basis to improve how resources are tagged. Better data completeness will lead
to more enlightening reports, so automatizing even further the data adquisition
stage will bene t all users.
6</p>
    </sec>
    <sec id="sec-6">
      <title>Acknowledgements</title>
      <p>The research activities described in this paper are partially funded by DeustoTech,
Deusto Institute of Technology, a research institute within the University of
Deusto and the Basque Government's Universities and Research department,
under grant PRE 2013 1 848.</p>
    </sec>
  </body>
  <back>
    <ref-list>
      <ref id="ref1">
        <mixed-citation>
          1.
          <string-name>
            <given-names>Mikel</given-names>
            <surname>Emaldi</surname>
          </string-name>
          , David Bujan, and Diego Lopez-de Ipina.
          <article-title>Towards the integration of a research group website into the web of data</article-title>
          . In CAEPIA - Conferencia
          <string-name>
            <surname>de la Asociacion</surname>
          </string-name>
          <article-title>Espan~ola para la Inteligencia Arti cial</article-title>
          ,
          <year>2011</year>
          .
        </mixed-citation>
      </ref>
      <ref id="ref2">
        <mixed-citation>
          2.
          <string-name>
            <given-names>Weimao</given-names>
            <surname>Ke</surname>
          </string-name>
          ,
          <string-name>
            <given-names>Katy</given-names>
            <surname>Borner</surname>
          </string-name>
          , and Lalitha Viswanath.
          <article-title>Major information visualization authors, papers and topics in the acm library</article-title>
          .
          <source>In Information Visualization</source>
          ,
          <year>2004</year>
          .
          <article-title>INFOVIS 2004</article-title>
          .
          <article-title>IEEE Symposium on</article-title>
          ,
          <source>page r1{r1. IEEE</source>
          ,
          <year>2004</year>
          .
        </mixed-citation>
      </ref>
      <ref id="ref3">
        <mixed-citation>
          3. Kevin W Boyack, Richard Klavans, and
          <article-title>Katy Borner. Mapping the backbone of science</article-title>
          .
          <source>Scientometrics</source>
          ,
          <volume>64</volume>
          (
          <issue>3</issue>
          ):
          <volume>351</volume>
          {
          <fpage>374</fpage>
          ,
          <year>2005</year>
          .
        </mixed-citation>
      </ref>
      <ref id="ref4">
        <mixed-citation>
          4.
          <string-name>
            <given-names>Anastasia</given-names>
            <surname>Dimou</surname>
          </string-name>
          , Laurens De Vocht, Geert Van Grootel,
          <string-name>
            <given-names>Leen Van Campe</given-names>
            ,
            <surname>Jeroen Latour</surname>
          </string-name>
          , Erik Mannens, and Rik Van de Walle.
          <article-title>Visualizing the information of a linked open data enabled research information system</article-title>
          . euroCRIS, May
          <year>2014</year>
          .
          <article-title>Delivered at the CRIS2014 Conference in Rome; to appear in the Procedia online CRIS2014 procs on ScienceDirect</article-title>
          .
        </mixed-citation>
      </ref>
      <ref id="ref5">
        <mixed-citation>
          5.
          <string-name>
            <given-names>Christian</given-names>
            <surname>Bizer</surname>
          </string-name>
          , Tom Heath, and
          <string-name>
            <surname>Tim</surname>
          </string-name>
          Berners-Lee.
          <article-title>Linked data-the story so far</article-title>
          .
          <source>International journal on semantic web and information systems</source>
          ,
          <volume>5</volume>
          (
          <issue>3</issue>
          ):1{
          <fpage>22</fpage>
          ,
          <year>2009</year>
          .
        </mixed-citation>
      </ref>
      <ref id="ref6">
        <mixed-citation>
          6. York Sure, Stephan Bloehdorn,
          <string-name>
            <given-names>Peter</given-names>
            <surname>Haase</surname>
          </string-name>
          , Jens Hartmann, and
          <string-name>
            <given-names>Daniel</given-names>
            <surname>Oberle</surname>
          </string-name>
          .
          <article-title>The SWRC ontology { semantic web for research communities</article-title>
          .
          <source>In Carlos Bento, Am lcar Cardoso</source>
          , and Gael Dias, editors,
          <source>Progress in Arti cial Intelligence, number 3808 in Lecture Notes in Computer Science</source>
          , pages
          <volume>218</volume>
          {
          <fpage>231</fpage>
          . Springer Berlin Heidelberg,
          <year>January 2005</year>
          .
        </mixed-citation>
      </ref>
      <ref id="ref7">
        <mixed-citation>
          7.
          <string-name>
            <surname>Vincent</surname>
            <given-names>D.</given-names>
          </string-name>
          <string-name>
            <surname>Blondel</surname>
          </string-name>
          ,
          <string-name>
            <surname>Jean-Loup</surname>
            <given-names>Guillaume</given-names>
          </string-name>
          , Renaud Lambiotte, and
          <string-name>
            <given-names>Etienne</given-names>
            <surname>Lefebvre</surname>
          </string-name>
          .
          <article-title>Fast unfolding of communities in large networks</article-title>
          .
          <source>Journal of Statistical Mechanics: Theory and Experiment</source>
          ,
          <year>2008</year>
          (
          <volume>10</volume>
          ):
          <fpage>P10008</fpage>
          ,
          <year>October 2008</year>
          . arXiv:
          <volume>0803</volume>
          .
          <fpage>0476</fpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref8">
        <mixed-citation>
          8.
          <string-name>
            <given-names>Martin</given-names>
            <surname>Everett</surname>
          </string-name>
          and
          <string-name>
            <given-names>Stephen P.</given-names>
            <surname>Borgatti</surname>
          </string-name>
          .
          <article-title>Ego network betweenness</article-title>
          .
          <source>Social Networks</source>
          ,
          <volume>27</volume>
          (
          <issue>1</issue>
          ):
          <volume>31</volume>
          {
          <fpage>38</fpage>
          ,
          <year>January 2005</year>
          .
        </mixed-citation>
      </ref>
      <ref id="ref9">
        <mixed-citation>
          9.
          <string-name>
            <given-names>Jie</given-names>
            <surname>Tang</surname>
          </string-name>
          , Jing Zhang, Limin Yao,
          <string-name>
            <given-names>Juanzi</given-names>
            <surname>Li</surname>
          </string-name>
          ,
          <string-name>
            <given-names>Li</given-names>
            <surname>Zhang</surname>
          </string-name>
          , and
          <string-name>
            <given-names>Zhong</given-names>
            <surname>Su</surname>
          </string-name>
          .
          <article-title>Arnetminer: extraction and mining of academic social networks</article-title>
          .
          <source>In Proceedings of the 14th ACM SIGKDD international conference on Knowledge discovery and data mining, page</source>
          <volume>990</volume>
          {
          <fpage>998</fpage>
          . ACM,
          <year>2008</year>
          .
        </mixed-citation>
      </ref>
    </ref-list>
  </back>
</article>