<!DOCTYPE article PUBLIC "-//NLM//DTD JATS (Z39.96) Journal Archiving and Interchange DTD v1.0 20120330//EN" "JATS-archivearticle1.dtd">
<article xmlns:xlink="http://www.w3.org/1999/xlink">
  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>OntoBacen: A Modular Ontology for Risk Management in the Brazilian Financial System</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Filipe Polizel</string-name>
          <email>fpolizel@ime.usp.br</email>
          <xref ref-type="aff" rid="aff2">2</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Sara Casare</string-name>
          <email>sjcasare@uol.com.br</email>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Jaime Sichman</string-name>
          <email>jaime.sichman@poli.usp.br</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Escola Polite ́cnica, Universidade de Sa ̃o Paulo</institution>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>IBM do</institution>
          <country country="BR">Brasil</country>
        </aff>
        <aff id="aff2">
          <label>2</label>
          <institution>Instituto de Matema ́tica e Estat ́ıstica, Universidade de Sa ̃o Paulo</institution>
        </aff>
      </contrib-group>
      <abstract>
        <p>This paper presents a first semantic formalization of the Brazilian financial system risk management policies, called OntoBacen, that is based on a modularized approach. We show some partial results generated by a knowledge-based system that uses an ontology constructed to address some domain questions.</p>
      </abstract>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>-</title>
      <p>Episodes like global crisis undermine people’s confidence
in the financial system, but also provide lessons for the
future. The 2007-2008 meltdown resulted in a significative
advancement of governance policies followed by financial
institutions worldwide, with some of them treating classic
data management problems, as integrity and completeness.
To enable the adoption of an integrated and robust global
financial system, IT companies and financial institutions are
joining efforts for the creation and adoption of a
technological framework to better meet the industry needs.</p>
      <p>The main goal of this work is to explore alternative
approaches for the conceptualization and definition of
business rules present in governance policies of the Brazilian
financial system, more specifically those related to risk
management. To this end, it proposes an ontology, called
OntoBacen, that expresses the concepts (and their relationships)
of this domain, and by using inference algorithms, can
verify the compliance of hypothetical financial institutions with
those policies.</p>
      <p>For such a wide and complex domain, modularity must
play a central role in the design of the proposed solution,
to ensure that it results in an coherent, understandable and
scalable knowledge-based system.</p>
      <p>In the following section, the risk management setting of
the Brazilian financial system is briefly introduced. We then
present the main initiatives involving ontologies for the
financial industry, followed by a description of OntoBacen
by means of its properties and requirements. In the sequence,
we show the modularization approach adopted by the
proposed solution, followed by a section that details how
OntoBacen has been developed and how it’s meant to be used.
Some test cases illustrate the use of the proposed
ontology, followed by current conclusions and future
development steps.</p>
    </sec>
    <sec id="sec-2">
      <title>Financial Industry Risk Management</title>
      <p>The main good practices for the governance of the global
financial system were established and formalized by the Basel
Committee on Banking Supervision (BCBS), forming part
of the Bank for International Settlements (BIS), that in
postcrisis periods identified the need for a robust data
management framework. This must ensure that banks have the
capacity to aggregate risk exposure data in an integrated
manner, reaching all the corporation levels, in addition to
standardized risk reporting practices (BIS 2013a), confering the
degrees of assertiveness and timeliness required by
institutional leaders for decision-making in times of stress.</p>
      <p>
        Once established the core principles for banking
supervision
        <xref ref-type="bibr" rid="ref5 ref7">(BIS 1997; BIS 2012)</xref>
        , central banks around the globe
have taken them as basis for the establishment of their own
regulatory norms. Moreover, they also considered the
singularities of their domestic financial systems, what partially
mitigated the level of heterogeneity of the global financial
system risk management domain. However, this was not
sufficient to achieve the goal of representing these domain
concepts and their relationships in an integrated manner
worldwide, which demands the use of highly integrable and
logically grounded tools, such as the use of formal ontologies
        <xref ref-type="bibr" rid="ref11">(Guarino 1995)</xref>
        in the Semantic Web
        <xref ref-type="bibr" rid="ref15 ref4">(Berners-Lee, Handler,
and Lassila 2001)</xref>
        .
      </p>
      <p>
        The policies and guidelines to be followed by the
Brazilian financial institutions are created and maintained by the
local monetary authorities, but mainly by the executive
authority of the national financial system, the Brazil Central
Bank, also known as BACEN. In order to align their
governance policies with the Basel principles, the Brazilian
monetary authorities created a series of norms, known as
prudential regulation
        <xref ref-type="bibr" rid="ref3">(BACEN 2014)</xref>
        , to be followed by local
banks and financial institutions. The main goal of the
prudential regulation is to consolidate a national system for risk
management and capital adequacy.
      </p>
      <p>These regulations are arranged to take into account the
main types of risk, described as follows:
Credit Risk Associated with the risk of default, the failure
to comply with obligations and responsibilities.</p>
      <p>Market Risk Related to the volatility of rates or prices over
the time, such as currency exchange and interest rates, or
prices of securities and commodities.</p>
      <p>Operational Risk Associated with the probability of loss
resulting from internal processes failures or deficiencies,
including legal risks, such as damages to third parties
arising from its activities, or violation of rules established in
their jurisdiction.</p>
      <p>This business division of the domain suggests that
modularity should be taken into account (and exploited to the
fullest) when dealing with risk management.</p>
    </sec>
    <sec id="sec-3">
      <title>Ontologies for Financial Industry</title>
      <p>In recent years, with the greater control over the financial
systems by regulatory agencies, the need for information
systems interoperability and data integration has increased,
which strengthened initiatives related to finance on the
Semantic Web; these initiatives, allied with the ontologies’
semantic formalism, have gained their place and importance in
this specific industry.</p>
      <p>
        As an example, the Suggested Upper Merged Ontology
        <xref ref-type="bibr" rid="ref15 ref4">(Niles and Pease 2001)</xref>
        , also known as SUMO, has included
its own finance domain ontology years ago, dealing with
concepts related primarily to financial services, typical of
commercial banks, such as bank accounts, payments, loans,
etc. A more recent work (in progress at the time of
writing), is the Financial Report Ontology1 (FRO), which
provides formal and structured meta-information about
financial reports, such as balance-sheets; it is primarily based
on a well-known XML schema for this application domain,
XBRL
        <xref ref-type="bibr" rid="ref1">(Engel et al. 2013)</xref>
        , that stands for eXtensible
Business Reporting Language.
      </p>
      <p>Other relevant initiative is the Financial Industry
Business Ontology2 (FIBO), a series of standards being
developed by the Enterprise Data Management Council (EDMC)
and published following the technical governance process of
the Object Management Group (OMG). FIBO currently
provides a framework of conceptual definitions concerning the
wide spectrum of financial applications, currently available
for use in two modules.</p>
      <p>The first module, FIBO foundations, defines high-level
financial concepts such as currency or contracts, and even
non-financial concepts such as autonomous agent or
country, that are need for the definition of more specific
financial concepts. The second module, FIBO Business Entities,
defines concepts such as legal persons and corporations,
entities that could incur legal obligations such as establishing
business contracts with other entities.</p>
      <p>
        There are also ontological initiatives concerning financial
regulations, where lies the scope of this work. Abi-Lahoud
et al. (2013) developed an ontology concerning the
compliance with American anti-money-laundering regulations;
later, Abi-Lahoud, OBrien, and Butler (2013) presented an
experimental discussion about the adopted approach, an
iterative process based on subject-matter expertise and on the
use of structured natural language, more precisely based
on SBVR
        <xref ref-type="bibr" rid="ref16">(OMG 2008)</xref>
        , that stands for Semantics of
Business Vocabulary and Business Rules, a structured
vocabulary founded in formal logic.
      </p>
      <p>1See: http://xbrl.squarespace.com/financial-report-ontology/.
2See: http://www.omgwiki.org/OMG-FDTF/doku.php.</p>
      <p>These initiatives are being conducted with the support of
the Governance, Risk and Compliance Technology Centre3
(GRCTC), also responsible for the development of the
Financial Industry Regulatory Ontology (FIRO) and the
Financial Governance, Risk and Compliance Ontology (FIGO).</p>
    </sec>
    <sec id="sec-4">
      <title>OntoBacen Proposal</title>
      <p>The final and main goal of this work is to create an
ontology to represent the Brazilian financial system, by means
of its risk management concepts, and to be implemented in
the Web Ontology Language (OWL). In this sense, it is
related to some of the ontologies mentioned in the previous
section, while considering BACEN’s governance policies, as
published in its norms.</p>
      <p>A Brazilian financial jargon says that BACEN’s
regulations are the “tropicalization of Basel”. To exemplify this
statement, when comparing BACEN and Basel standardized
approaches to evaluate market risks, one can conclude that
the BACEN approach has an additional component of risk
for fixed interest rates denominated in the local currency
(real), making it a conservative adaptation of the Basel
approach (BIS 2013b).</p>
      <p>
        The specification of OntoBacen, by means of its
requirements, is given by a set of competence questions
        <xref ref-type="bibr" rid="ref10 ref9">(Gru¨ninger
and Fox 1995)</xref>
        , as shown in the following:
CQ1: What is the capital structure, by means of its
components, of a financial institution that belongs to the
Brazilian financial system?
CQ2: What are the maximum and minimum constraints for
the capital components of a Brazilian financial institution?
CQ3: What are the cash amounts that represent each capital
component of a Brazilian financial institution?
CQ4: Do the capital components of a Brazilian financial
institution respect its constraints?
      </p>
      <p>The definition of capital component used in this paper is
that of a grouping of assets or liabilities, possibly weighted
by some factor and represented by an amount of money.</p>
      <p>Aditionally, for the development of the proposed
ontology, a methodology partially based on the GRCTC
methodology (adopted by FIRO and FIGO) will be used, as shown
in the Construction and Usage section.</p>
    </sec>
    <sec id="sec-5">
      <title>OntoBacen Modularization</title>
      <p>The BACEN’s prudential regulation is the starting point for
the definition of OntoBacen. It was analyzed in a top-down
approach, beginning with the most high-level view,
represented by the notions related to the methodology for
calculation of the Reference Capital, later reaching the
lowerlevel related concepts. In this sense, by the interpretation
of a series of BACEN documents, the lower level concepts
were identified, introducing definitions related to several
approaches for the measurement of different types of risk.</p>
      <p>After this domain analysis, some core modules were
identified for the development process, as shown in Figure 1.</p>
      <sec id="sec-5-1">
        <title>3See: http://www.grctc.com/platform-research/.</title>
        <p>Foundations</p>
        <p>RWA
MaRrkWet ARisk</p>
        <p>Credit Risk
Operational Risk</p>
        <p>Banking Book Risk</p>
        <p>Primarily, the FIBO Foundations and FIBO Business
Entities ontologies were chosen to provide the highest level of
semantics, such as the has part property, a whole-part
relationship frequently used by OntoBacen, or even concepts
common in finance, such as currency.</p>
        <p>Some additional concepts not present in FIBO were
defined to provide mid-level semantics, constituting the
module Foundations, that is supposed to be used by other
modules and ontologies of OntoBacen; it is composed by a set
of ontologies described later in this section.</p>
        <p>The lower level ontologies are then separated in two major
disjoint groups: Capital and RWA. The first group addresses
the definition of capital, that is represented in an
accounting perspective by shareholder’s equity, savings and other
kinds of liabilities. The second group name is an acronym
for Risk Weighted Assets, that also in an accounting
perspective consists of the values of assets weighted by distinct
types of risks according to the degree of risk exposure; these
two groups encompass the concepts that must be defined for
addressing CQ1.</p>
        <p>To exemplify how RWA captures the notion of risk, one
could think, for instance, in a market risk perspective, if you
have a given amount of resources applied in the stock
market and the same amount of resources applied in treasury
bonds, it is expected that the weighting factor of the first
group is higher than the second one’s weighting factor, and
consequently its RWA, because of the probability that the
company which some stocks was acquired enter bankruptcy
is higher than that of the government defaulting.</p>
        <p>Each one of these groups were then divided in minor (and
also disjoint) modules. Capital group takes into account
BACEN major definitions to do these separation, being
decomposed in Tier 1 Core, Tier 1 Complementary and Tier
2 ontologies. The same group also encompasses a
Permanent Limit ontology, that is used to reduce the amount of
capital used for requirements checking, in cases that
permanent assets exceed a certain limit.</p>
        <p>The RWA group considered the division for risk
management mentioned in the first section, resulting in
different ontologies for Market Risk, Credit Risk and
Operational Risk. An additional ontology Banking Book Risk
was added to treat the risk related to interest rates of
banking book assets, i.e. those acquired and meant to be held until
their maturity, because the risk exposure calculation method
for these cases is different from the standard market risk for
interest rates approach.</p>
        <p>An additional reason to adopt such modularization is that
these subdomains are commonly subject of distinct business
areas in financial institutions (specially the big ones). In this
sense, the compliance area is more willing to treat issues
addressed by the Capital ontologies, the market risk
management area to those of the Market Risk ontology, and so
forth, in such a way that those areas could consult specific
ontologies as semantics repositories or even use its inference
capabilities to address their own issues.</p>
        <p>Finally, an additional ontology, Capital Requirements,
deals with the capital adequacy questions mentioned in the
proposal section. It is related to concepts defined in both
Capital and RWA ontologies, and contains the definitions
of business rules necessary for addressing CQ2.</p>
        <p>Currently, the Foundations, Market Risk and Capital
Requirements ontologies are ready to be used, as detailed
in the sequence. Consequently, the capital adequacy
competence questions address only market risk exposure.</p>
        <sec id="sec-5-1-1">
          <title>Foundations Module</title>
          <p>This module is composed of four foundational ontologies,
described as follows:
Common Relations Ontology that defines a set of data and
object properties required by other ontologies, such as:
1. mathematical properties, to define product, minimum,
maximum, and other derivation relationships;
2. time constraints properties, such as initial and ending
date (xsd:dateTime), minimum and maximum duration
(xsd:duration), needed for time intervals definition;
3. the has reference date property, needed for the
definition of financial system governance contexts;
4. the has decimal value property, used to define factors;
BACEN Factors Ontology for the definition of constant or
time dependant factors present in BACEN regulations.
Time dependancy is defined by fixed xsd:dateTime
intervals or fixed xsd:duration intervals relative to a specific
date;
Financial Institutions Ontology encompassing concepts
that define the Brazilian financial system agents, such as:
1. The financial institutions classification, specializing the
concept for legal person from FIBO Business Entities.
Examples are commercial banks, investiment banks,
securities brokerages, etc.;
2. The concept of monetary authority, that also is a legal
person, and used to define BACEN;
3. The concepts for classification of institutions into
compliant or not-compliant to specific regulatory norms;
Contextualized Monetary Amount Ontology for the
definition of a generic context concept, and also:
1. The contextualized monetary amount concept is a
specialization of FIBO Foundations monetary amount
concept, something that has a currency and an amount, and
that additionally has a context (uses FIBO Foundations
has currency, has amount and has context properties);
2. The financial system governance context concept, that
specializes context, and also involves a monetary
authority governing and constraining the behavior of a
financial institution at a specific moment in time (uses
FIBO Foundations is governed by and constrains
properties).</p>
          <p>The contextualized monetary amount concept is used to
represent amounts of cash related someway to a financial
system governance context, thus it is the major definition of
OntoBacen for addressing CQ3.</p>
        </sec>
        <sec id="sec-5-1-2">
          <title>Market Risk Ontology</title>
          <p>The main goal of this ontology is to provide a way to
evaluate the market risk exposure by using at least one of the
approaches available. Its semantics translates the business
rules needed to obtain the market risk RWA (risk weighted
assets by market risk exposure).</p>
          <p>
            Figure 2 shows its main concepts and their relationships
using a notation similar to VOWL
            <xref ref-type="bibr" rid="ref13">(Lohmann et al. 2014)</xref>
            ,
where concepts are represented as circles (filling colors
indicate modules), relationships (properties) as plain-line arrows
and generalization relationships as dotted-line arrows.
          </p>
          <p>The first important thing to note is that there are two
possible appoaches to evaluate the market risk RWA, the
standardized approach (called RWAMPAD) and the
internal model approach (called RWAMINT). Both of these
approaches have more specific concepts that are omitted here
for a matter of simplicity.</p>
          <p>In both cases, financial institutions must verify their
market risk exposure by the standardized approach, because
even the internal model approach depends on the
standardized. In addition, they are not required to have (or to use)
an internal model, but in the cases that both approaches are
implemented, one of them must be chosen.</p>
          <p>To opt for the internal approach, the institution must show
to BACEN that the proposed model actually maps the
market risk efficiently and that it is consistent with the
regulations and norms. When opting for this model, things get a bit
messy, because in this case, some conservative constraints
for the evaluation of the RWA must be considered.</p>
          <p>Firstly, a market risk model transition factor (defined as
Sm) must be considered. This factor assumes the value of
90% in the first year of the transition, and 80% after that.
This weighting factor is then applied to the standardized
approach, producing an intermediate result, the standardized
approach considering Sm factor. From the results obtained
by both the application of the internal model approach and
the standardized approach considering Sm factor, the greater
of these is defined as the internal model RWA.</p>
          <p>Independently of the values for the market risk RWA
obtained by different approaches, institutions must choose one
of them to report BACEN. OntoBacen’s current
implementation chooses, in cases where the two models are evaluated,
RWAMINT
(int. model
has part approach)</p>
          <p>RWAMPAD is derived from
considering product of
Sm factor
RWAMINT
components
(omitted)</p>
          <p>is derived from is derived from
ismdaexriivmeudmfroofm maximum of product of
market
risk RWA
component</p>
          <p>RWAMINT
considering
Sm factor</p>
          <p>RWAMPAD
(standard
approach)
relative
time
dependant
factor
OB Market Risk
OB Foundations
generalization
custom relationship
the smallest (by comparing the has amount data property);
in the other cases, where there is only the standardized
approach, this latter is the one to be reported.</p>
          <p>The market risk ontology defines the concepts
mentioned before as specializations of contextualized monetary
amount. A general market risk RWA concept is defined, so
that it encompasses any market risk evaluation approach,
being naturally specialized by the two approaches previously
mentioned, and by an additional concept for the approach
that was chosen to be reported to BACEN.</p>
          <p>The intermediate results used in the evaluation of the
market risk RWA are conceptualized as specializations of an
additional concept market risk RWA component. Finally, the
Sm factor concept is classified as a specialization of
relative time dependant factor, defined by Factors ontology
and whose semantics define that its value is dependant of
the amount of time elapsed from a specific date (in this case,
the market risk model transition date).</p>
        </sec>
        <sec id="sec-5-1-3">
          <title>Capital Requirements Ontology</title>
          <p>There are different capital requirements specified by the
BACEN regulations, such as minimum requirements for tier
1 capital and reference capital. The latter is the most
general (and relevant) definition of capital, so that this
requirements rules was chosen as the first to be implemented by
the Capital Requirements ontology. For the
implementation of capital requirements rules related to more specific
concepts, such as tier 1 capital, some efforts will be needed
in the construction of ontologies for the Capital module,
described in the beginning of this section, and working in
progress at the moment of writing.</p>
          <p>The main idea of this ontology is to compare the risk
weighted assets with some liabilities composition, defined in
this case as reference capital, and that is mainly composed
by reserves and shareholder’s equity. To define the concept
of risk weighted assets, it is necessary to consider all types
of risk (such as the market risk mentioned before),
aggregating these multiple risk types as a general and single concept.
For that, all ontologies of the RWA module must be
available; as already mentioned before, at this moment the capital
requirements ontology is considering only market risk as a
risk type.</p>
          <p>The minimum required reference capital can be
determinimum
required
reference
capital
mined from the risk weighted assets, as depicted by the
dependency relationship between these concepts in Figure 3.
This minimum requirement amount is given by applying a
numerical factor (reference capital requirement factor) to
the RWA, whose value decreases yearly (11% before 2016,
9.875% at 2016, 9.25% at 2017, 8.625% at 2018 and 8%
after 2018). This fixed time interval dependancy is represented
as an specialization of the concept time interval dependant
factor of the Factors ontology.</p>
          <p>Before this comparison between the reference capital and
its minimum requirement could be done, the excess of
permanent assets must be discounted from the capital, resulting
in an additional concept for comparison between capital and
RWA: reference capital for rwa comparation. This excess is
determined by additional business rules, omitted here,
because they are in the scope of the Permanent Limit
ontology, not yet constructed.</p>
          <p>Another important concept definition is that of margin
over required reference capital, which is given by the
difference between the capital component, considering any
necessary deductions such as the excess of permanent assets,
and the minimum required capital. From the margin over
required reference capital, one can determine if a financial
institution is compliant with the capital requirements
verifying if its value is non-negative, analogous analysis could be
made to determine if the institution is non-compliant
(negative margin).</p>
          <p>Given these final considerations, concepts like reference
capital requirement compliant and reference capital
requirement non-compliant can be defined (shown as part of an
external ontology in Figure 3), which indicate the compliance
(or not) of some Brazilian financial institution to BACEN’s
prudential regulation at a specific time.</p>
        </sec>
      </sec>
    </sec>
    <sec id="sec-6">
      <title>Construction and Usage</title>
      <p>The nine steps for developing and using OntoBacen are
shown in Figure 4. The six first steps are for the ontology
construction, while the last three are for its usage. BACEN’s
prudential regulation is the input to this methodology, and is
available as a set of .pdf files written in Portuguese, that are
copied to an easily editable format, such as text files.</p>
      <p>Input:
Bacen norms
1.Follow
references
ref.</p>
      <p>X</p>
      <p>X
6.Manipulate
namespaces,</p>
      <p>imports,
cardinalities,
labels, etc.</p>
      <p>Enrich semantics</p>
      <p>by adding
SWRL rules.</p>
      <p>.owl
+SWRL
TBox
ABox</p>
      <p>.txt (NL)
2.Self-contained,
complete
sentences
3.Extract terms and
rules to SBVR
.sbvr (SNL)
for each module</p>
      <p>(steps 6-9)
7.Generate
individuals
with custom
application
(Jena +
SPARQL)
.rdf
.s.sb.sbvbrvrvr
.o.wo.owlwl l
5.Convert SBVR</p>
      <p>to OWL
(formal logic)</p>
      <p>Input:
Operational
capital limit
report file</p>
      <p>.xml
9.Get answers
with new
knowledge
?
8.Infer new axioms by
using an OWL and
SWRL compatible
inference engine
new
axioms
In the first step, it is needed to follow reference chains
present in such norms, to construct, in a second step,
semantically complete and self-contained sentences in natural
language (Portuguese), by cutting and pasting portions of the
original text.</p>
      <p>After that, in the third step, the self-contained sentences
are interpreted in order to achieve a first level of formality,
identifying and representing its terms and rules with SBVR
(structured natural language). Note that there isn’t a SBVR
structured vocabulary for Portuguese; in this sense,
relationships and rules are translated to English so they can be based
on SBVR-SE (SBVR Structured English), but terms
(concepts) are kept in their original form.</p>
      <p>Marinos, Gazzard, and Krause 2011 proposed the creation
of a tool for the manipulation of SBVR vocabularies with
auto-completion and highlighting features, work that later
evoluted to SBVR Lab 2.04, a tool freely available on the
Web; this tool was used to help achieving the goals of the
third step.</p>
      <p>The fourth step begins with the possession of the SBVR
vocabulary; its terms and rules are distributed in a set of
distinct vocabularies, mainly by considering their subject
matter, what inevitably demands interpretation and expertise of
the domain; secondly, we take into account technical
considerations, in order to achieve, for instance, a higher degree
of disjointness between vocabularies, and thus minimizing
the number of relationships between terms of distinct sets.
Other important issue involves the detection of core terms,</p>
      <sec id="sec-6-1">
        <title>4See: http://www.sbvr.co/.</title>
        <p>those that are extensively related to other terms, and should
be organized in such a manner that could be easily shared
between multiple modules.</p>
        <p>All these initial steps involves human interpretation and
manual activities to be accomplished; they demand
familiarity with Brazilian legal writing, as the BACEN’s norms
are written similarly to any other Brazilian law document
(legalese), and also require prior knowledge about its subject
matter, since these norms aren’t designed to be educational.</p>
        <p>The fifth step is the conversion of these multiple SBVR
vocabularies to OWL 2.0, generating the ontology modules.
Some works in the literature address the conversion between
these two languages without semantics loss, however a more
detailed description is beyond the scope of this paper.
Karpovic and Nemuraite 2011 worked in the field, resulting in
the creation of a conversion tool freely available on the Web,
called s2o5. The initial step for the creation of OntoBacen
OWL files used this tool6.</p>
        <p>In the sixth step, the initial OWL files obtained from s2o
are subjected to manipulations in order to complement and
enrich their semantics. For that, the Prote´ge´7 software was
used to:
• Add or update namepaces and ontology imports;
• Include some cardinality restrictions not captured in the</p>
        <p>SBVR vocabularies phase;
• Add labels and other annotation properties useable for
documenting the ontology (in Portuguese and English);
• Create SWRL rules to allow the inference of additional
axioms, including the use of its built-in functions for math
and date operations.</p>
        <p>At this point, each OWL file is the final version of an
ontology, concluding the terminological component (TBox) of
the system.</p>
        <p>The main reason to adopt such approach is because
manipulating a large vocabulary such as the BACEN’s
prudential regulation, is made quickly by just listing its terms and
rules in text files than formalizing all them in ontology
development tools. In this sense, for OntoBacen’s initial
development phase, described in this paper, only small subsets
of the identified concepts were subjected to the formal
ontology engineering process (step 6).</p>
        <p>For the construction of the assertion component (ABox),
the input artifact for the definition of instances of the
ontology classes (individuals) is the DLO8, a XML report file
that Brazilian financial institutions must submit to BACEN,
briefly depicted in Figure 5.</p>
        <p>This file, containing the data required for the possible
assertions which one can infer by the use of OntoBacen,
is available in accordance with a XML Schema similar to
accounting, where each structure is composed basically of
5See: http://s2o.isd.ktu.lt/about.php.</p>
        <p>6It was necessary to apply a simple syntax transformation
algorithm in this step, whose details are beyond the scope of this paper.
7See: http://protege.stanford.edu.</p>
        <p>8DLO is an acronym for Demonstrativo de Limites
Operacionais in Portuguese, and stands for operational limit statement.
&lt;documentoDLO cnpj="12345678" dataBase="2012-05"&gt;
&lt;limitesInformados&gt; Reference Date
&lt;/..l.imitesLIisntfoofrRmeapdoortse&gt;d Limits Legal Person Identifier
&lt;parametros&gt; Reference Capital
... List of Parameters (Account Code = 100) Account
&lt;/parametros&gt; Value
&lt;contas&gt;
s &lt;conta codigoConta="100" valorConta="2139.00" /&gt;
tn &lt;conta codigoConta="101" valorConta="2129.00" /&gt;
cuo &lt;conta codigoConta="102" valorConta="2049.00" /&gt;
cA ...
fo &lt;conta codigoConta="900" valorConta="1067.00" /&gt;
itsL &lt;&lt;ccoonnttaa ccooddiiggooCCoonnttaa==""995600"" vvaalloorrCCoonnttaa==""160645.9.0000""//&gt;&gt;
&lt;/contas&gt;
&lt;/documentoDLO&gt;
a numerical identification code, and an amount of money
(Brazilian reais).</p>
        <p>A Java application was developed to do the XML
deserialization, that also used Apache Jena framework (with some
help of SPARQL queries), for the automatic instantiation of
the individuals to be later used in conjunction with
OntoBacen. The final result is a set of RDF files, following the
same modularization approach used in the ontology creation
phase.</p>
        <p>
          From now on, all components required for the reasoning
phase are ready. The reasoning can be done through a
specific module, subsets of modules, or even all of them. In
this phase, an inference engine compatible with SWRL rules
must be used; for the test cases presented in this paper, Pellet
          <xref ref-type="bibr" rid="ref17">(Sirin et al. 2007)</xref>
          was used for such a task.
        </p>
        <p>Finally, by using the set of inferred axioms, one can
get the answers to the proposed competence questions, for
instance: a Brazilian financial institution complies to
BACEN’s prudential regulation in a determined context, if it is
classified as capital requirement compliant in that context.</p>
        <p>Notice that each module can answer some limited and
specific questions, for instance: the Market Risk ontology
can only determine the degree of exposure to market risk,
and that isn’t sufficient to verify the compliance or not to
BACEN’s prudential regulation; the presented competence
questions have a higher level of complexity, and need some
reasoning over all modules of the ontology so that they can
be answered.</p>
      </sec>
    </sec>
    <sec id="sec-7">
      <title>Test Cases</title>
      <p>For testing the proposed knowledge system capabilities, a
standard example of the DLO was used, as provided by
BACEN. From there, three additional test cases were created
by altering elements of the XML file, so that their
instantiation could be automatically done by the custom application
mentioned in the construction and usage section.</p>
      <p>Table 1 shows the relevant input data of the four test cases,
in millions of Brazilian reais, and for a matter of simplicity,
the market risk RWA models were consolidated by its
components, as it was shown in Figure 2.</p>
      <p>According to the information shown in Table 1,
OntoBacen can apply business rules by using an inference engine
compliant with OWL and SWRL rules, in order to answer if
the institutions in each case are compliant or not with
BACEN’s capital requirements regulations, considering their
exposure to market risk.</p>
      <p>Case 1 is the default example provided by BACEN9. In
this case, only the standardized market risk approach is used,
so that it is necessarily the reported one, and the reference
capital is more than five times higher than the reported RWA,
with a highly positive margin over the required reference
capital, resulting in the inference of such institution as
compliant to the capital requirements.</p>
      <p>In case number 2, both models are implemented, but the
standardized model indicates a lower risk exposure than the
internal model, and as OntoBacen is configured to choose
the minimum exposure approach (this isn’t obligatory), the
standardized approach is chosen to be reported. This
institution has a high amount of permanent assets, so that the
reference capital is halved when reduced by the excess of
permanent assets, making the minimum required reference capital
higher in comparison with this amount, resulting in a
nega9The operational limit statement XML files are available at:
http://www.bcb.gov.br/fis/pstaw10/leiaute limitesDLO.asp.
tive margin over the required reference capital and therefore
the conclusion that it is not adherent to the norms.</p>
      <p>Case 3 has both models implemented too, but the internal
approach indicates the lower risk exposure (being reported),
not sufficiently low to break the barrier of the standardized
approach weighted by the Sm factor (90% in this case
because the model transition was done in less than a year).
Additionally, the reference date is now at the year of 2016,
when the reference capital requirement decreases from 11%
to 9.875% of the RWA, and finally results in a handily
positive margin over the required capital, concluding that this
case is compliant.</p>
      <p>In the last case, number 4, the market risk approaches
differ greatly from one another, in such a manner that even the
Sm factor being of 80% (since the model transition
happened more than a year before the reference date), the
internal model broke the barrier of the standardized approach
weighted by Sm, so that the final RWA value by the
internal model will be the same of the barrier. As in this case
the internal model will assume 80% the value of the
standardized approach, OntoBacen will choose it for being the
lower one. The minimum required reference capital is then
evaluated from the resulting RWA and compared with a
minor value, which brings to a negative margin and the
conclusion of non-compliance to BACEN’s capital requirements
regulations.</p>
      <p>All test cases executed the mentioned inferences in few
seconds, by using Pellet reasoner within Prote´ge´, so that
computational performance was adequate, since this isn’t a
real time problem. The time for loading required ontologies
from the Web was approximately thirty seconds.</p>
      <p>OntoBacen currently deals with very general and
aggregated concepts, so that performance was not a great
concern yet. However, as the level of detail (and data) increases,
to deal with all data at once could be a performance issue,
given the exponential nature of reasoning systems; this is
another reason to consider modularity, alongside with
distributed reasoning, as a primary design requirement for
modeling this domain.</p>
    </sec>
    <sec id="sec-8">
      <title>Conclusions</title>
      <p>This paper presented an alternative technical approach for
dealing with risk management: instead of the standard
specialized systems, we propose to use ontology-based
technologies together with a knowledge-based system.</p>
      <p>Our proposal provides an open knowledge reference to
address issues of this domain, freely available in the
Semantic Web10; its semantics provides a formal
representation of rules established by BACEN’s prudential regulation,
and also a computational artifact that along with automated
reasoning can provide answers to the user.</p>
      <p>By the use of such approach, any Brazilian financial
institution that needs to report accounting and risk indicators
to BACEN by using an XML operational limit statement
(which has only syntactical and structural constraints,
without formal semantics), could verify its semantic consistency
before submission, or even generate semantically consistent
10URI: http://lti.pcs.usp.br/⇠ filipe.polizel/OntoBacen/.
content, avoiding mistakes and delays that can bring
eventual penalties and losses.</p>
      <p>Finally, for the effective success of such solution,
modularity must play a central role in its design from the
beginning to the end, allowing financial institutions to take
advantage of computational features such as distributed
computing and avoiding to handle massive amounts of knowledge
at once, given the exponential computational complexity of
logical reasoning algorithms.</p>
    </sec>
    <sec id="sec-9">
      <title>Further Work</title>
      <p>This work intends to further explore the BACEN regulations
in order to define business rules for other risk types, such
as credit and operational risk. Besides, the ontologies for
capital definition will be created so that the reference
capital concept can be decomposed in more detailed definitions.
Therefore, the Capital Requirements ontology could be
enriched in order to consider all possible types of risk, and
capital requirements rules could be evaluated in additional
levels, such as tier 1 capital requirements.</p>
      <p>Other issue concerns the integration capabilities of the
proposed ontology. In order to address that, additional
semantic alignments can be done between OntoBacen and
other ontologies, while the work on financial ontologies
(FIBO, FIRO, etc) progresses. Another possible approach
for this question would be consider additional ontologies as
possible semantic foundations, such as a mathematics
ontology to express some of the relations identified in
OntoBacen (derivation of concepts by differences, maximums, etc).</p>
      <p>As these goals are achieved, additional efforts can be done
in such a way to deepen the concepts definition for each
subdomain that composes the governance of a financial system
risk management, increasing the proposed system
granularity and thus allowing it to treat additional risk management
questions (or even accounting). To this end, a lot of work in
the interpretation of an extensive set of BACEN regulation
documents should be done, and as the ontology evolve in
depth of details, new modular considerations must be taken
into account, such as those discussed in this paper.</p>
      <p>After the construction of the modules proposed in the
specification section, this work also aims to evaluate the
approach using a more realistic case study, by applying
OntoBacen rules with the data of a real Brazilian financial
institution, that is publicly available via balance sheets and risk
reports, or even by collecting more detailed data using the
operational limit statement XML sent to BACEN by some
institutions.</p>
    </sec>
    <sec id="sec-10">
      <title>Acknowledgements</title>
      <p>Jaime Sichman partially financed by CNPq, Brazil, proc.
303950/2013-7.</p>
      <sec id="sec-10-1">
        <title>Core principles for efRetrieved from last access on</title>
      </sec>
      <sec id="sec-10-2">
        <title>Core principles for ef</title>
        <p>Retrieved from
last access on
[BIS 2013a] BIS. 2013a. Principles for effective risk data
aggregation and risk reporting.
[BIS 2013b] BIS. 2013b. Regulatory consistency
assessment programme (rcap) assessment of basel iii regulations
in brazil.
[Engel et al. 2013] Engel, P.; Hamscher, W.; Shuetrim, G.;
vun Kannon, D.; and Wallis, H. 2013. Extensible business
reporting language (xbrl) 2.1.</p>
      </sec>
    </sec>
  </body>
  <back>
    <ref-list>
      <ref id="ref1">
        <mixed-citation>
          [
          <string-name>
            <surname>Abi-Lahoud</surname>
          </string-name>
          et al. 2013]
          <article-title>Abi-</article-title>
          <string-name>
            <surname>Lahoud</surname>
            ,
            <given-names>E.</given-names>
          </string-name>
          ;
          <string-name>
            <surname>Butler</surname>
            ,
            <given-names>T.</given-names>
          </string-name>
          ;
          <string-name>
            <surname>Chapin</surname>
            ,
            <given-names>D.</given-names>
          </string-name>
          ; and Hall,
          <string-name>
            <surname>J.</surname>
          </string-name>
          <year>2013</year>
          .
          <article-title>Interpreting regulations with sbvr</article-title>
          .
          <source>In Proceedings of RuleML (2)</source>
          '
          <fpage>13</fpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref2">
        <mixed-citation>
          <string-name>
            <surname>[</surname>
          </string-name>
          Abi-Lahoud, OBrien, and Butler 2013]
          <article-title>Abi-</article-title>
          <string-name>
            <surname>Lahoud</surname>
            , E.; OBrien, L.; and Butler,
            <given-names>T.</given-names>
          </string-name>
          <year>2013</year>
          .
          <article-title>On the road to regulatory ontologies: Interpreting regulations with sbvr</article-title>
          .
          <source>AICOL.</source>
        </mixed-citation>
      </ref>
      <ref id="ref3">
        <mixed-citation>
          <source>[BACEN 2014] BACEN</source>
          .
          <year>2014</year>
          .
          <article-title>Regulac¸a˜o prudencial</article-title>
          .
          <source>Retrieved</source>
          from https://www.bcb.gov.br/?REGPRUDENCIAL, last access on
          <source>2015 Apr</source>
          <volume>12</volume>
          .
        </mixed-citation>
      </ref>
      <ref id="ref4">
        <mixed-citation>
          [
          <string-name>
            <surname>Berners-Lee</surname>
          </string-name>
          , Handler, and Lassila 2001]
          <article-title>Berners-</article-title>
          <string-name>
            <surname>Lee</surname>
            ,
            <given-names>T.</given-names>
          </string-name>
          ;
          <string-name>
            <surname>Handler</surname>
          </string-name>
          , J.; and
          <string-name>
            <surname>Lassila</surname>
            ,
            <given-names>O.</given-names>
          </string-name>
          <year>2001</year>
          .
          <article-title>The semantic web</article-title>
          .
        </mixed-citation>
      </ref>
      <ref id="ref5">
        <mixed-citation>
          <source>[BIS 1997] BIS</source>
          .
          <year>1997</year>
          .
        </mixed-citation>
      </ref>
      <ref id="ref6">
        <mixed-citation>
          http://www.bis.org/publ/bcbs30a.pdf,
          <source>2014 Aug 8.</source>
        </mixed-citation>
      </ref>
      <ref id="ref7">
        <mixed-citation>
          <source>[BIS 2012] BIS</source>
          .
          <year>2012</year>
          .
        </mixed-citation>
      </ref>
      <ref id="ref8">
        <mixed-citation>
          http://www.bis.org/publ/bcbs230.pdf,
          <source>2014 Aug 8.</source>
        </mixed-citation>
      </ref>
      <ref id="ref9">
        <mixed-citation>
          <source>[Gru¨ninger and Fox</source>
          <year>1995</year>
          ]
          <article-title>Gru¨ninger, M., and</article-title>
          <string-name>
            <surname>Fox</surname>
          </string-name>
          , M. S.
        </mixed-citation>
      </ref>
      <ref id="ref10">
        <mixed-citation>
          1995.
          <article-title>Methodology for the design and evaluation of ontologies.</article-title>
        </mixed-citation>
      </ref>
      <ref id="ref11">
        <mixed-citation>
          [Guarino 1995] Guarino,
          <string-name>
            <surname>N.</surname>
          </string-name>
          <year>1995</year>
          .
          <article-title>Formal ontology, conceptual analysis and knowledge representation</article-title>
          .
          <source>International Journal of Human and Computer Studies</source>
          <volume>43</volume>
          :
          <fpage>625</fpage>
          -
          <lpage>640</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref12">
        <mixed-citation>
          <source>[Karpovic and Nemuraite</source>
          <year>2011</year>
          ] Karpovic,
          <string-name>
            <given-names>J.</given-names>
            , and
            <surname>Nemuraite</surname>
          </string-name>
          ,
          <string-name>
            <surname>L.</surname>
          </string-name>
          <year>2011</year>
          .
          <article-title>Transforming sbvr business semantics into web ontology language owl2: Main concepts</article-title>
          .
          <source>In Proceedings of the 17th international conference on Information and Software Technologies (IT</source>
          <year>2011</year>
          ),
          <fpage>231</fpage>
          -
          <lpage>238</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref13">
        <mixed-citation>
          [Lohmann et al. 2014]
          <string-name>
            <surname>Lohmann</surname>
            ,
            <given-names>S.</given-names>
          </string-name>
          ;
          <string-name>
            <surname>Negru</surname>
            ,
            <given-names>S.</given-names>
          </string-name>
          ;
          <string-name>
            <surname>Haag</surname>
            ,
            <given-names>F.</given-names>
          </string-name>
          ; and Ertl,
          <string-name>
            <surname>T.</surname>
          </string-name>
          <year>2014</year>
          .
          <article-title>Vowl 2: User-oriented visualization of ontologies</article-title>
          .
          <source>In Proceedings of the 19th International Conference on Knowledge Engineering and Knowledge Management</source>
          , EKAW '
          <volume>14</volume>
          ,
          <fpage>266</fpage>
          -
          <lpage>281</lpage>
          . Springer.
        </mixed-citation>
      </ref>
      <ref id="ref14">
        <mixed-citation>
          [Marinos, Gazzard, and Krause 2011]
          <string-name>
            <surname>Marinos</surname>
            ,
            <given-names>A.</given-names>
          </string-name>
          ;
          <string-name>
            <surname>Gazzard</surname>
            ,
            <given-names>P.</given-names>
          </string-name>
          ; and Krause,
          <string-name>
            <surname>P.</surname>
          </string-name>
          <year>2011</year>
          .
          <article-title>An sbvr editor with highlighting and auto-completion.</article-title>
        </mixed-citation>
      </ref>
      <ref id="ref15">
        <mixed-citation>
          <source>[Niles and Pease</source>
          <year>2001</year>
          ]
          <string-name>
            <surname>Niles</surname>
            ,
            <given-names>I.</given-names>
          </string-name>
          , and
          <string-name>
            <surname>Pease</surname>
            ,
            <given-names>A.</given-names>
          </string-name>
          <year>2001</year>
          .
          <article-title>Towards a standard upper ontology</article-title>
          .
          <source>In Proceedings of the 2nd International Conference on Formal Ontology in Information Systems (FOIS</source>
          <year>2001</year>
          ). ACM.
          <article-title>See also www</article-title>
          .
          <source>ontologyportal.org.</source>
        </mixed-citation>
      </ref>
      <ref id="ref16">
        <mixed-citation>
          <source>[OMG 2008] OMG</source>
          .
          <year>2008</year>
          .
          <article-title>Semantics of business vocabulary and business rules (sbvr</article-title>
          ),
          <year>v1</year>
          .
          <fpage>0</fpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref17">
        <mixed-citation>
          [Sirin et al. 2007]
          <string-name>
            <surname>Sirin</surname>
            ,
            <given-names>E.</given-names>
          </string-name>
          ;
          <string-name>
            <surname>Parsia</surname>
            ,
            <given-names>B.</given-names>
          </string-name>
          ;
          <string-name>
            <surname>Grau</surname>
            ,
            <given-names>B. C.</given-names>
          </string-name>
          ;
          <string-name>
            <surname>Kalyanpur</surname>
            ,
            <given-names>A.</given-names>
          </string-name>
          ; and Katz,
          <string-name>
            <surname>Y.</surname>
          </string-name>
          <year>2007</year>
          .
          <article-title>Pellet: A practical owl-dl reasoner</article-title>
          .
          <source>Web Semantics: Science, Services and Agents on the World Wide Web archive</source>
          <volume>5</volume>
          :
          <fpage>51</fpage>
          -
          <lpage>53</lpage>
          .
        </mixed-citation>
      </ref>
    </ref-list>
  </back>
</article>