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  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>Using Semantic Web Technologies for Explaining and Predicting Abnormal Expenses</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Freddy Le´cue´</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>John Vard</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Jiewen Wu</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Accenture Technology Labs</institution>
          ,
          <country country="IE">Ireland</country>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>INRIA</institution>
          ,
          <country country="FR">France</country>
        </aff>
      </contrib-group>
      <abstract>
        <p>Travel expenses represent up to 7% of organisations overall budget. Existing expenses systems are designed for reporting expenses types and amount, but not for understanding how to save and spend. We present a system, manipulating semantic web technologies, which aims at identifying, explaining, predicting abnormal expense claims by employees of large organisations in 500+ cities. Abnormality Detection Description: This service retrieves abnormal accommodation price in a given fcityg, fcountryg for year 2015 worldwide.</p>
      </abstract>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>-</title>
      <p>Time and expense in most companies is the process of recording and tracking hours
worked and expenses as they relate to projects. $546 Billion worldwide has been
estimated to be lost because of non spend optimisation in the process of managing expenses
at organisation level. We address the problem of spend optimisation i.e., determining
how to save and spend. Our system, AIFS (Accenture Intelligent Finance System),
aims at (i) identifying, (ii) explaining and (iii) predicting abnormal expenses e.g., flight,
accommodation, entertainment (denoted as abnormalities) in 500+ cities. The system
is mainly used by (i) travel and expenses business owner to better manage spend
optimisation, (ii) expenses auditor for tracking abnormal expenses, and (iii) internal travel
system administrator for defining expenses policy based on the reasoning results.</p>
      <p>Our system is exposing a semantic description of causation between external events
and expenses type. It leverages open data (e.g., events), LOD and reasoning
functionalities to expose causation using semantic representation in RDF. DBpedia and Wikidata
are used by our system for representing heterogeneous data together with explanation,
and then by our back-end reasoning engine for semantic association.
Our system exposes three core functionalities: abnormality (i) detection, (ii)
explanation, and (iii) prediction. They cover the particular case of accommodation price
variance over time in 500+ cities. All functionalities consume JSON inputs and expose
back JSON, RDF and JSON-LD with contexts mapped to the LOD cloud. JSON-LD
has been considered for further easy integration in any application.
2.1</p>
      <p>Output: Abnormal accommodation prices are detected in 500+ cities. The JSON
description captures the type of expenses, its date, its severity level (scaled from 1 to 5 as
the most severe), its average and observed amount in US dollar. The RDF description
exposes semantics of the search and abnormalities. For instance, cities and countries
are contextualised using their DBpedia resources.</p>
      <p>Back-end Technology: A standard statistical analysis of data has been conducted to
detect abnormal expenses. An analysis of 300,000+ unique travellers in 500+ cities
worldwide with a minimum and maximal number of respectively 2,521 and 24,800
expenses per city recorded for 2015 has been initially performed.
2.2</p>
    </sec>
    <sec id="sec-2">
      <title>Abnormality Explanation</title>
      <p>Description: We retrieve semantic explanation of abnormal price of accommodation
in a given fcityg and fcountryg between fdate startg and fdate endg.
1
2
3</p>
      <sec id="sec-2-1">
        <title>Data analysis for spatial interpretation of abnormalities: abnormal expenses</title>
      </sec>
      <sec id="sec-2-2">
        <title>Semantic explanation (structured in classes: fraud, events, seasonal) of abnormalities</title>
      </sec>
      <sec id="sec-2-3">
        <title>Detailed semantic explanation (structured in sub classes e.g. categories for events)</title>
        <p>Output: Semantic explanation, contextualised using DBpedia and Wikidata, of
abnormal accommodation price is provided in 500+ cities. Contributing factors (scaled from
0 to 100), categorised as frauds, external events, city capacity, season together with
their types (e.g., music category for social event) are provided c.f. Figure 1. Besides
RDF schema, an internal ontology, characterising links across categories, is also used.</p>
        <p>
          Back-end Technology: Abnormality explanation has been achieved by applying core
principles of explanatory reasoning [
          <xref ref-type="bibr" rid="ref1">1</xref>
          ]. In a nutshell, the reasoning task of explaining
anomalies (abnormal high price of accommodation) consists in interpreting the impact
of external events (e.g., social events, seasonal effect). The interpretation is achieved
by measuring the semantic similarity (through ontology matching) of any 4-uple of the
form &lt; city; accommodation; event; impact &gt; where city, accommodation, event
and impact are defined by respectively 89, 41, 24 and 11 semantic properties using
vocabularies of DBpedia and Wikidata.
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        </p>
        <sec id="sec-2-3-1">
          <title>Context:</title>
        </sec>
        <sec id="sec-2-3-2">
          <title>Paris - France</title>
        </sec>
        <sec id="sec-2-3-3">
          <title>Prediction of accommodation in Paris – France in 2016</title>
        </sec>
        <sec id="sec-2-3-4">
          <title>Historical data of accommodation in Paris – France in 2016</title>
        </sec>
        <sec id="sec-2-3-5">
          <title>Time Span</title>
        </sec>
        <sec id="sec-2-3-6">
          <title>Events classified by categories</title>
        </sec>
        <sec id="sec-2-3-7">
          <title>Explanation of high accommodation price</title>
          <p>2.3</p>
        </sec>
      </sec>
    </sec>
    <sec id="sec-3">
      <title>Abnormality Prediction</title>
      <p>Description: The system retrieves prediction of accommodation price and its
explanation when the price is abnormally high.</p>
      <p>
        Back-end Technology: Prediction of abnormality has been achieved by applying core
principles of predictive reasoning [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ] and revisiting the application domain in [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ]. In
a nutshell, the reasoning task of predicting anomalies (abnormal high price of
accommodation) consists in capturing the context (using semantic representation of events
and their categories with DBpedia and Wikidata vocabularies) and attaching it to
accommodation price. Prediction is achieved by capturing semantic association rules, and
reasoning over their content and the initial knowledge background (capturing the
context of cities, population, density, events, among others).
3
      </p>
      <p>Data and Vocabularies</p>
      <p>
        Background Data in Use: We define background data as data consumed silently by
the system with no user specification. Only relevant background data (i.e., data which
could be mapped to DBpedia, Wikidata for semantic comparison cf. [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ]) is transformed
in RDF for reasoning purpose. The size in column “Size per day” is the maximal amount
of data collected i.e., for diagnosing / predicting abnormal price of accommodation in
all cities.
      </p>
      <p>Data</p>
      <p>Source
300,000+ unique travel- Min. and max. number
lers in 500+ cities of respectively 2,521 and
recorded for 2015 24,800 expenses per citya</p>
      <p>Social events
e.g., music event,
political event
.93 (complete)
.41 (aggregated)</p>
      <p>Private
a https://www.eventbrite.com/api
b http://api.eventful.com
c http://wiki.dbpedia.org/Datasets
d https://www.wikidata.org/wiki/Wikidata:Database download
e http://54.194.213.178:8111/ExplanatoryReasoning/ontology/categories.n3
4 Conclusion and Plan for Extensibility
We presented AIFS (Accenture Intelligent Finance System) i.e., a system for
interpreting, explaining and predicting abnormally high expense using accommodation price as
abnormality in 500+ cities. The system, exposing semantic descriptions of causation
between events and expenses type, is mainly used by (i) travel and expenses business
owner to better manage spend optimisation, (ii) expenses auditor for tracking
abnormal expenses, and (iii) internal travel system administrator for defining expenses policy
based on the reasoning results. Semantics has been crucial to contextualise and interpret
expenses and their amount.</p>
    </sec>
  </body>
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