Research Publications

Aircraft are valuable asset to the military and must be protected against different threats. One such a threat is shoulder-launched missiles which are portable, easy to use and easy to come by. To counter this the military deploy various kinds of countermeasures on aircraft against these attacks. In order to assist in the development, evaluation and deployment of the countermeasures, modeling and simulation are used. One such a system is the Optronic Scene Simulator, an engineering tool used to model and evaluate infra-red countermeasures to make recommendations for the deployment thereof. Ontologies are no longer a foreign concept in the computer and information sciences eld - it plays a valuable role in making systems more valuable. An ontology, Simtology, was developed to support the the simulation system in various ways such as providing a shared vocabulary, improve understanding of the concepts in the environment and add value through suitable functionality.

@misc{50,
  author = {Nelia Lombard and Aurona Gerber and Alta van der Merwe},
  title = {Using Formal Ontologies in the Development of Countermeasures for Military Aircraft},
  abstract = {Aircraft are valuable asset to the military and must be protected
against different threats. One such a threat is shoulder-launched
missiles which are portable, easy to use and easy to come by. To counter
this the military deploy various kinds of countermeasures on aircraft
against these attacks. In order to assist in the development, evaluation
and deployment of the countermeasures, modeling and simulation are
used. One such a system is the Optronic Scene Simulator, an engineering
tool used to model and evaluate infra-red countermeasures to make
recommendations for the deployment thereof. Ontologies are no longer a
foreign concept in the computer and information sciences eld - it plays a
valuable role in making systems more valuable. An ontology, Simtology,
was developed to support the the simulation system in various ways such
as providing a shared vocabulary, improve understanding of the concepts
in the environment and add value through suitable functionality.},
  year = {2012},
}

The Object Role Modeling language (ORM2) is one of the main conceptual modeling languages. Recently, it has been proposed a translation of a main fragment of ORM2 (ORM2zero) into the description logic ALCQI, allowing the use of logical instruments in the analysis of ORM schemas. On the other hand, in many ontological domains there is a need for the formalization of defeasible information and of nonmonotonic forms of reasoning. Here we introduce two new constraints in the ORM2 language, in order to formalize defeasible information into the schemas, and we explain how to translate such defeasible information in ALCQI.

@misc{49,
  author = {Giovanni Casini and A. Mosca},
  title = {Defeasible reasoning in ORM2},
  abstract = {The Object Role Modeling language (ORM2) is one of the main conceptual modeling languages. Recently, it has been proposed a translation of a main fragment of ORM2 (ORM2zero) into the description logic ALCQI, allowing the use of logical instruments in the analysis of ORM schemas. On the other hand, in many ontological domains there is a need for the formalization of defeasible
information and of nonmonotonic forms of reasoning. Here we introduce two new constraints in the ORM2 language, in order to formalize defeasible information into the schemas, and we explain how to translate such defeasible information in ALCQI.},
  year = {2012},
}

In the field of non-monotonic logics, the lexicographic closure is acknowledged as a a powerful and logically well-characterized approach; we are going to see that such a construction can be applied in the field of Description Logics, an important knowledge representation formalism, and we shall provide a simple decision decision procedure.

@misc{48,
  author = {Giovanni Casini and Umberto Straccia},
  title = {Lexichographic Closure for Defeasible Description Logics.},
  abstract = {In the field of non-monotonic logics, the lexicographic closure is acknowledged as a a powerful and logically well-characterized approach; we are going to see that such a construction can be applied in the field of Description Logics, an important knowledge representation formalism, and we shall provide a simple decision decision procedure.},
  year = {2012},
}

This paper describes the development of an ontology for use in a military simulation system. Within the military, aircraft represent a signicant investment and these valuable assets need to be protected against various threats. An example of such a threat is shoulder-launched missiles. Such missiles are portable, easy to use and unfortunately, rela- tively easy to acquire. In order to counter missile attacks, countermea- sures are deployed on the aircraft. Such countermeasures are developed, evaluated and deployed with the assistance of modelling and simulation systems. One such system is the Optronic Scene Simulator, an engineer- ing tool that is able to model and evaluate countermeasures in such a way that the results could be used to make recommendations for successful deployment and use. The use of formal ontologies is no longer a foreign concept in the support of information systems. To assist with the simulations performed in the Optronic Scene Simulator, an ontology, Simtology, was developed. Sim- tology supports the system in various ways such as providing a shared vocabulary, improving the understanding of the concepts in the environ- ment and adding value by providing functionality that improves integra- tion between system components.

@misc{42,
  author = {Nelia Lombard and Aurona Gerber and Alta van der Merwe},
  title = {Using Formal Ontologies in the Development of Countermeasures for Military Aircraft.},
  abstract = {This paper describes the development of an ontology for use
in a military simulation system. Within the military, aircraft represent
a signicant investment and these valuable assets need to be protected
against various threats. An example of such a threat is shoulder-launched
missiles. Such missiles are portable, easy to use and unfortunately, rela-
tively easy to acquire. In order to counter missile attacks, countermea-
sures are deployed on the aircraft. Such countermeasures are developed,
evaluated and deployed with the assistance of modelling and simulation
systems. One such system is the Optronic Scene Simulator, an engineer-
ing tool that is able to model and evaluate countermeasures in such a way
that the results could be used to make recommendations for successful
deployment and use.
The use of formal ontologies is no longer a foreign concept in the support
of information systems. To assist with the simulations performed in the
Optronic Scene Simulator, an ontology, Simtology, was developed. Sim-
tology supports the system in various ways such as providing a shared
vocabulary, improving the understanding of the concepts in the environ-
ment and adding value by providing functionality that improves integra-
tion between system components.},
  year = {2012},
  journal = {Using Formal Ontologies in the Development of Countermeasures for Military Aircraft.},
  url = {http://ceur-ws.org/Vol-969/paper9.pdf},
}

Modularization is an important part of the modular design and maintenance of large scale ontologies. Syntactic locality-based mod-ules, with their desirable model theoretic properties, play an ever in-creasing role in the design of algorithms for modularization, partitioning and reasoning tasks such as classication. It has been shown that, for the DL EL+, the syntactic locality module extraction problem is equiv-alent to the reachability-based problem for hypergraphs. In this paper we investigate and introduce a normal form for the DL SROIQ which allows us to map any SROIQ ontology to an equivalent hypergraph. We then show that standard hyperpath searching algorithms can be used to extract syntactic locality based modules for SROIQ ontologies.

@misc{41,
  author = {Riku Nortjé and Katarina Britz and Tommie Meyer},
  title = {A normal form for hypergraph-based module extraction for SROIQ},
  abstract = {Modularization is an important part of the modular design and maintenance of large scale ontologies. Syntactic locality-based mod-ules, with their desirable model theoretic properties, play an ever in-creasing role in the design of algorithms for modularization, partitioning and reasoning tasks such as classication. It has been shown that, for
the DL EL+, the syntactic locality module extraction problem is equiv-alent to the reachability-based problem for hypergraphs. In this paper we investigate and introduce a normal form for the DL SROIQ which allows us to map any SROIQ ontology to an equivalent hypergraph. We then show that standard hyperpath searching algorithms can be used to
extract syntactic locality based modules for SROIQ ontologies.},
  year = {2012},
  journal = {8th Australasian Ontology Workshop (AOW 2012)},
  month = {4/12},
}

The formal definition of abduction asks what needs to be added to a knowledge base to enable an observation to be entailed by the knowledge base. ABox abduction in description logics (DLs) asks what ABox statements need to be added to a DL knowledge base, to allow an observation (also in the form of ABox statements) to be entailed. Klarman et al. have provided an algorithm for performing ABox abduction in the description logic ALC by converting the knowledge base and observation to first-order logic, using a connection tableau to obtain abductive solutions, and then converting these back to DL syntax. In this paper we describe how this can be done directly using a DL tableau.

@misc{40,
  author = {Ken Halland and Katarina Britz},
  title = {Naive ABox abduction in ALC using a DL tableau},
  abstract = {The formal definition of abduction asks what needs to be added to a knowledge base to enable an observation to be entailed by the knowledge base. ABox abduction in description logics (DLs) asks what ABox statements need to be added to a DL knowledge base, to allow an observation (also in the form of ABox statements) to be entailed. Klarman et al. have provided an algorithm for performing ABox abduction in the description logic ALC by converting the knowledge base and observation to first-order logic, using a connection tableau to obtain abductive solutions, and then converting these back to DL syntax. In this paper we describe how this can be done directly using a DL tableau.},
  year = {2012},
  url = {http://ceur-ws.org/Vol-846/paper_47.pdf},
}

The formal definition of abduction asks what needs to be added to a knowledge base to enable an observation to be entailed by the knowledge base. ABox abduction in description logics (DLs) asks what ABox statements need to be added to a DL knowledge base to allow an observation (also in the form of ABox statements) to be entailed. Klarman et al. have provided an algorithm for performing ABox abduction in the description logic ALC by converting the knowledge base and observation to first-order logic, using a connection tableau to obtain abductive solutions, and then converting these back to DL syntax. In this paper we describe how this can be done directly using a DL tableau.

@{39,
  author = {Ken Halland and Katarina Britz},
  title = {ABox abduction in ALC using a DL tableau},
  abstract = {The formal definition of abduction asks what needs to be added to a knowledge base to enable an observation to be entailed by the knowledge base. ABox abduction in description logics (DLs) asks what ABox statements need to be added to a DL knowledge base to allow an observation (also in the form of ABox statements) to be entailed. Klarman et al. have provided an algorithm for performing ABox abduction in the description logic ALC by converting the knowledge base and observation to first-order logic, using a connection tableau to obtain abductive solutions, and then converting these back to DL syntax. In this paper we describe how this can be done directly using a DL tableau.},
  year = {2012},
  journal = {SAICSIT 2012: Proceedings of the 2012 Annual Research Conference of the South African Institute for Computer Scientists and Information Technologists, 1-3 October 2012, Centurion, South Africa},
}

One of the most successful approaches to the formalization of commonsense reasoning is the work by Lehmann and colleagues, known as the KLM approach, in which defeasible consequence relations with a preferential semantics are studied. In spite of its success, KLM is limited to propositional logic. In recent work we provided the semantic foundation for extending defeasible consequence relations to modal logics and description logics. In this paper we continue that line of investigation by going beyond the basic (propositional) KLM postulates, thereby making use of the additional expressivity provided by modal logic. In particular, we show that the additional constraints we impose on the preferential semantics ensure that the rule of necessitation holds for the corresponding consequence relations, as one would expect it to. We present a representation result for this tightened framework, and investigate appropriate notions of entailment in this context - normal entailment, and a rational version thereof.

@{37,
  author = {Katarina Britz and Tommie Meyer and Ivan Varzinczak},
  title = {Normal Modal Preferential Consequence},
  abstract = {One of the most successful approaches to the formalization of commonsense reasoning is the work by Lehmann and colleagues, known as the KLM approach, in which defeasible consequence relations with a preferential semantics are studied. In spite of its success, KLM is limited to propositional logic. In recent work we provided the semantic foundation for extending defeasible consequence relations to modal logics and description logics. In this paper we continue that line of investigation by going beyond the basic (propositional) KLM postulates, thereby making use of the additional expressivity provided by modal logic. In particular, we show that the additional constraints we impose on the preferential semantics ensure that the rule of necessitation holds for the corresponding consequence relations, as one would expect it to. We present a representation result for this tightened framework, and investigate appropriate notions of entailment in this context - normal entailment, and a rational version thereof.},
  year = {2012},
  journal = {Proceedings of the 25th Australasian Joint Conference on Artificial Intelligence},
  pages = {505-516},
}

Most belief change operators in the AGM tradition assume an underlying plausibility ordering over the possible worlds which is transitive and complete. A unifying structure for these operators, based on supplementing the plausibility ordering with a second, guiding, relation over the worlds was presented in Booth et al. (Artif Intell 174:1339–1368, 2010). However it is not always reasonable to assume completeness of the underlying ordering. In this paper we generalise the structure of Booth et al. (Artif Intell 174:1339–1368, 2010) to allow incomparabilities between worlds. We axiomatise the resulting class of belief removal functions, and show that it includes an important family of removal functions based on finite prioritised belief bases.

@article{35,
  author = {Richard Booth and Tommie Meyer and C. Sombattheera},
  title = {A General Family of Preferential Belief Removal Operators},
  abstract = {Most belief change operators in the AGM tradition assume an underlying plausibility ordering over the possible worlds which is transitive and complete. A unifying structure for these operators, based on supplementing the plausibility ordering with a second, guiding, relation over the worlds was presented in Booth et al. (Artif Intell 174:1339–1368, 2010). However it is not always reasonable to assume completeness of the underlying ordering. In this paper we generalise the structure of Booth et al. (Artif Intell 174:1339–1368, 2010) to allow incomparabilities between worlds. We axiomatise the resulting class of belief removal functions, and show that it includes an important family of removal functions based on finite prioritised belief bases.},
  year = {2012},
  journal = {Journal of Philosophical Logic},
  volume = {41},
  pages = {711-733},
  issue = {4},
  url = {http://www.springerlink.com/content/f6368324072g3344/},
}

We propose a non-standard modal logic for specifying agent domains where the agent’s actuators and sensors are noisy, causing uncertainty in action and perception. The logic is multi-modal, indexed with actions; the logic is also augmented with observation objects to facilitate knowledge engineers dealing with explicit observations in the environment, and it includes a notion of probability. A tableau method is provided for proving decidability of the proposed logic. It is our conjecture that the tableau rules are complete with respect to the semantics. The proof does not yet exist, however, we discuss the current approach of the proof and provide some examples to motivate our conjecture.

@{34,
  author = {Gavin Rens and G. Lakemeyer and Tommie Meyer},
  title = {A Logic for Specifying Agent Actions and Observations with Probability},
  abstract = {We propose a non-standard modal logic for specifying agent domains where the agent’s actuators and sensors are noisy, causing uncertainty in action and perception. The logic is multi-modal, indexed with actions; the logic is also augmented with observation objects to facilitate knowledge engineers dealing with explicit observations in the environment, and it includes a notion of probability. A tableau method is provided for proving decidability of the proposed logic. It is our conjecture that the tableau rules are complete with respect to the semantics. The proof does not yet exist, however, we discuss the current approach of the proof and provide some examples to motivate our conjecture.},
  year = {2012},
  journal = {Kersting, K., Toussaint, M. (Eds.), Sixth Starting AI Researchers' Symposium (STAIRS 2012), Frontiers in Artificial Intelligence and Applications, Vol. 241},
  pages = {252-263},
}

No Abstract

@misc{31,
  author = {Katarina Britz and Ivan Varzinczak},
  title = {Defeasible Modes of Inference: A Preferential Perspective},
  abstract = {No Abstract},
  year = {2012},
  url = {http://www.dbai.tuwien.ac.at/NMR12/proceedings.html},
}

No Abstract

@misc{22,
  author = {Ivan Varzinczak},
  title = {Preferential Reasoning: Beyond Propositional Logic and Argument Forms},
  abstract = {No Abstract},
  year = {2012},
}

We introduce Propositional Typicality Logic (PTL), a logic for reasoning about typicality. We do so by enriching classical propositional logic with a typicality operator of which the intuition is to capture the most typical (or normal) situations in which a formula holds. The semantics is in terms of ranked models as studied in KLM-style preferential reasoning. This allows us to show that rational consequence relations can be embedded in our logic. Moreover we show that we can define consequence relations on the language of PTL itself, thereby moving beyond the propositional setting. Building on the existing link between propositional rational consequence and belief revision, we show that the same correspondence holds for rational consequence and belief revision on PTL. We investigate entailment for PTL, and propose two appropriate notions thereof.

@{21,
  author = {Richard Booth and Tommie Meyer and Ivan Varzinczak},
  title = {PTL: A Propositional Typicality Logic},
  abstract = {We introduce Propositional Typicality Logic (PTL), a logic for reasoning about typicality. We do so by enriching classical propositional logic with a typicality operator of which the intuition is to capture the most typical (or normal) situations in which a formula holds. The semantics is in terms of ranked models as studied in KLM-style preferential reasoning. This allows us to show that rational consequence relations can be embedded in our logic. Moreover we show that we can define consequence relations on the language of PTL itself, thereby moving beyond the propositional setting. Building on the existing link between propositional rational consequence and belief revision, we show that the same correspondence holds for rational consequence and belief revision on PTL. We investigate entailment for PTL, and propose two appropriate notions thereof.},
  year = {2012},
  journal = {Proceedings of the 13th European Conference on Logics in Artificial Intelligence (JELIA)},
  pages = {107-119},
}

We discuss two approaches for defeasible reasoning in Description Logics that allow for the statement of defeasible subsumptions of the form "α subsumed by β usually holds". These approaches are known as prototypical reasoning and presumptive reasoning and are both rooted in the notion of Rational Closure developed by Lehmann and Magidor for the propositional case. Here we recast their definitions in a defeasible DL context and define algorithms for prototypical and presumptive reasoning in defeasible DL knowledge bases. In particular, we present a plug-in for the Protégé ontology editor which imple-ments these algorithms for OWL ontologies. The plug-in is called RaMP and allows the modeller to indicate defeasible information in OWL ontologies and check entailment of defeasible subsumptions from defeasible knowledge bases.

@misc{20,
  author = {Kody Moodley and Tommie Meyer and Ivan Varzinczak},
  title = {A Protege Plug-in for Defeasible Reasoning},
  abstract = {We discuss two approaches for defeasible reasoning in Description Logics that allow for the statement of defeasible subsumptions of the form "α subsumed by β usually holds". These approaches are known as prototypical reasoning and presumptive reasoning and are both rooted in the notion of Rational Closure developed by Lehmann and Magidor for the propositional case. Here we recast their definitions in a defeasible DL context and define algorithms for prototypical and presumptive reasoning in defeasible DL knowledge bases. In particular, we present a plug-in for the Protégé ontology editor which imple-ments these algorithms for OWL ontologies. The plug-in is called RaMP and allows the modeller to indicate defeasible information in OWL ontologies and check entailment of defeasible subsumptions from defeasible knowledge bases.},
  year = {2012},
  url = {http://ceur-ws.org/Vol-846/},
}

No Abstract

@misc{19,
  author = {Zubeida Khan and Maria Keet},
  title = {ONSET: Automated foundational ontology selection and explanantion},
  abstract = {No Abstract},
  year = {2012},
}

2012: Kinyondo, Josephat; van Biljon, Judy; Gerber, Aurona, 2012.The potential role of open source software in overcoming digital poverty, Alleviating Digital Poverty with ICT innovation in emerging economies. Will ICT Rights make a difference? IDIA2012 Conference Proceedings. 6th IDIA Conference. Steyn J, Kirlidog M. (eds). Beykent University, Istanbul, Turkey. 6-8 September. Pages 122-139. ISBN: 978-975-6319-17-8

@{18,
  author = {Josephat Kinyondo and Judy van Biljon and Aurona Gerber},
  title = {The potential role of open source software in overcoming digital poverty},
  abstract = {2012: Kinyondo, Josephat; van Biljon, Judy; Gerber, Aurona, 2012.The potential role of open source software in overcoming digital poverty,  Alleviating Digital Poverty with ICT innovation in emerging economies. Will ICT Rights make a difference? IDIA2012 Conference Proceedings. 6th IDIA Conference. Steyn J, Kirlidog M. (eds). Beykent University, Istanbul, Turkey. 6-8 September. Pages 122-139.  ISBN: 978-975-6319-17-8},
  year = {2012},
  journal = {6th IDIA Conference: Alleviating Digital Poverty with ICT innovation in emerging economies - Will ICT Rights make a difference?},
}

Most African countries have limited health information systems infrastructure. Some health information system components are implemented but often on an adhoc, piecemeal basis, by foreign software developers and designed to solve specific problems. Little attention is usually paid to how these components can fit into an integrated national health information system and interoperate with other components. The Health Enterprise Architecture Laboratory was recently established in the School of Computer Science at the University of KwaZulu-Natal in South Africa to undertake research and build capacity in open health architectures for developing African countries. Based on field experiences and requirements in South Africa, Mozambique and Rwanda, the laboratory is evolving a generic Health Enterprise Architecture Framework and Repository of Tools specifically for low resource settings. In this paper we describe these three initiatives and the expected impact on implementing health information systems in developing African countries.

@inbook{16,
  author = {Deshen Moodley and Anban Pillay and Chris Seebregts},
  title = {Position Paper: Researching and Developing Open Architectures for National Health Information Systems in Developing African Countries},
  abstract = {Most African countries have limited health information systems infrastructure. Some health information system components are implemented but often on an adhoc, piecemeal basis, by foreign software developers and designed to solve specific problems. Little attention is usually paid to how these components can fit into an integrated national health information system and interoperate with other components. The Health Enterprise Architecture Laboratory was recently established in the School of Computer Science at the University of KwaZulu-Natal in South Africa to undertake research and build capacity in open health architectures for developing African countries. Based on field experiences and requirements in South Africa, Mozambique and Rwanda, the laboratory is evolving a generic Health Enterprise Architecture Framework and Repository of Tools specifically for low resource settings. In this paper we describe these three initiatives and the expected impact on implementing health information systems in developing African countries.},
  year = {2012},
  journal = {Foundations of Health Informatics Engineering and Systems, Revised and Selected Papers, Lecture Notes in Computer Science Volume 7151},
  pages = {129-139},
  publisher = {Springer},
  url = {http://link.springer.com/chapter/10.1007/978-3-642-32355-3_8},
}

The debate ensues as to whether the traditional focus of computing research on theory development and verification and therefore has adequate immediate practical relevance. Despite increasing claims of the potential of design science research (DSR) to enhance the utility of the IT artifact and consequently practical relevance of research, many computing researchers seem to be reticent to accept this paradigm as a legitimate form of scholarly research. DSR is a relatively new paradigm in computing and little is known about its uptake in South Africa. In this paper, we investigate the opinions about DSR among South African computing scholars. Findings from a survey of 53 respondents indicate low adoption rates. The paper also investigates some of the key barriers preventing the uptake of DSR. The paper concludes with some implications as well as suggestions for building a local DSR community.

@{13,
  author = {Rennie Naidoo and Aurona Gerber and Alta van der Merwe},
  title = {An Exploratory Survey of Design Science Research among South African Computing Scholars},
  abstract = {The debate ensues as to whether the traditional focus of
computing research on theory development and verification and
therefore has adequate immediate practical relevance. Despite
increasing claims of the potential of design science research
(DSR) to enhance the utility of the IT artifact and consequently
practical relevance of research, many computing researchers seem
to be reticent to accept this paradigm as a legitimate form of
scholarly research. DSR is a relatively new paradigm in
computing and little is known about its uptake in South Africa. In
this paper, we investigate the opinions about DSR among South
African computing scholars. Findings from a survey of 53
respondents indicate low adoption rates. The paper also
investigates some of the key barriers preventing the uptake of
DSR. The paper concludes with some implications as well as
suggestions for building a local DSR community.},
  year = {2012},
  journal = {South African Institute for Computer Scientists and Information Technologists: SAICSIT 2012, Centurion, Tshwane. October 1-3.},
}

IST-Africa 2012 Conference Proceedings Paul Cunningham and Miriam Cunningham (Eds) IIMC International Information Management Corporation, 2012 ISBN: 978-1-905824-34-2

@{12,
  author = {Josephat Kinyondo and Judy van Biljon and Aurona Gerber},
  title = {An Assessment of Open Source Promotion in addressing ICT Acceptance Challenges in Tanzania},
  abstract = {IST-Africa 2012 Conference Proceedings
Paul Cunningham and Miriam Cunningham (Eds)
IIMC International Information Management Corporation, 2012
ISBN: 978-1-905824-34-2},
  year = {2012},
  journal = {IST Africa 2012},
}

http://www.sosa.org.za/sites/default/files/IEEE_BITF_SE12_Omnibus_Proceedings.pdf

@{11,
  author = {Aurona Gerber and Saurabh Sinha and Alta van der Merwe and Moshe Kam},
  title = {Accreditation of Academic Programmes in Computing in South Africa},
  abstract = {http://www.sosa.org.za/sites/default/files/IEEE_BITF_SE12_Omnibus_Proceedings.pdf},
  year = {2012},
  journal = {4th Software Engineering Colloquium (SE 2012)},
}

Rwanda, one of the smallest and most densely populated countries in Africa, has made rapid and substantial progress towards designing and deploying a national health information system. One of the challenging aspects of the system is the design of an architecture to support: interoperability between existing health information systems already in use in the country; incremental extension into a full integrated national health information system without substantial reengineering;and scaling, from a single district in the initial phase, to national level without requiring a fundamental change in technology or design paradigm. This paper describes the key requirements and the design of the current architecture using ISO/IEC/IEEE 42010 standard architecture descriptions. The architecture is based on the Enterprise Service Bus architectural model. We also describe a partial implementation of the architecture, and give a preliminary analysis based on our experiences.

@{10,
  author = {Ryan Crichton and Deshen Moodley and Anban Pillay and R. Gakuba and Chris Seebregts},
  title = {An Interoperability Architecture for the Health Information Exchange in Rwanda},
  abstract = {Rwanda, one of the smallest and most densely populated countries in Africa, has made rapid and substantial progress towards designing and deploying a national health information system. One of the challenging aspects of the system is the design of an architecture to support: interoperability between existing health information systems already in use in the country; incremental extension into a full integrated national health information system without substantial reengineering;and scaling, from a single district in the initial phase, to national level without requiring a fundamental change in technology or design paradigm. This paper describes the key requirements and the design of the current architecture using ISO/IEC/IEEE 42010 standard architecture descriptions. The architecture is based on the Enterprise Service Bus architectural model. We also describe a partial implementation of the architecture, and give a preliminary analysis based on our experiences.},
  year = {2012},
}

Sensor Web researchers are currently investigating middleware to aid in the dynamic discovery, integration and analysis of vast quantities of both high and low quality, but distributed and heterogeneous earth observation data. Key challenges being investigated include dynamic data integration and analysis, service discovery and semantic interoperability. However, few efforts deal with managing knowledge and system dynamism. Two emerging technologies that have shown promise in dealing with these issues are ontologies and software agents. This paper presents an integrated ontology driven agent based Sensor Web architecture for managing knowledge and system dynamism. An application case study on wildfire detection is used to illustrate the operation of the architecture.

@article{8,
  author = {Deshen Moodley and I. Simonis and J. Tapamo},
  title = {An architecture for managing knowledge and system dynamism in the worldwide Sensor Web},
  abstract = {Sensor Web researchers are currently investigating middleware to aid in the dynamic discovery, integration and analysis of vast quantities of both high and low quality, but distributed and heterogeneous earth observation data. Key challenges being investigated include dynamic data integration and analysis, service discovery and semantic interoperability. However, few efforts deal with managing knowledge and system dynamism. Two emerging technologies that have shown promise in dealing with these issues are ontologies and software agents. This paper presents an integrated ontology driven agent based Sensor Web architecture for managing knowledge and system dynamism. An application case study on wildfire detection is used to illustrate the operation of the architecture.},
  year = {2012},
  journal = {International Journal of Semantic Web and Information Systems: Special issue on Semantics-enhanced Sensor Networks, Internet of Things and Smart Devices},
  volume = {8},
  pages = {64-88},
  issue = {1},
  url = {http://www.igi-global.com/article/architecture-managing-knowledge-system-dynamism/70587},
}

Conceptual modeling is nowadays mostly done using languages such as Entity-Relationship (ER) Models, Unified Modeling Language (UML), and Object-Role Modeling (ORM). These models are used to depict the ontological organization of relevant concepts or entities. Such models share a common modeling approach, based on the notions of class or entity and the relations or associations between classes or entities. Recent developments in knowledge representation using logic-based ontologies have created new possibilities for conceptual data modeling. It also raises the question of how existing conceptual models using ER, UML or ORM could be translated into Description Logics (DLs), a family of logics that have proved to be particularly appropriate for formalizing ontologies and reasoning about them. Given a conceptual data model, two assumptions are usually made that are not explicitly stated but need to be clarified for its DL translation: (1) disjointness assumption: all the classes are to be assumed pairwise disjoint if not specified otherwise; and (2) covering assumption: the content of every class must correspond to the union of its immediate subclasses (this includes the assumption that we do not consider anything apart from what is expressed in the model). In this paper we propose two simple procedures to assist modelers with integrating these assumptions into their models, thereby allowing for a more complete translation into DLs.

@{7,
  author = {Giovanni Casini and Aurona Gerber and Tommie Meyer},
  title = {A Note on the Translation of Conceptual Data Models into Description Logics: Disjointness and Covering Assumptions},
  abstract = {Conceptual modeling is nowadays mostly done using languages such as Entity-Relationship (ER) Models, Unified Modeling Language (UML), and Object-Role Modeling (ORM). These models are used to depict the ontological organization of relevant concepts or entities. Such models share a common modeling approach, based on the notions of class or entity and the relations or associations between classes or entities. Recent developments in knowledge representation using logic-based ontologies have created new possibilities for conceptual data modeling. It also raises the question of how existing conceptual models using ER, UML or ORM could be translated into Description Logics (DLs), a family of logics that have proved to be particularly appropriate for formalizing ontologies and reasoning about them. Given a conceptual data model, two assumptions are usually made that are not explicitly stated but need to be clarified for its DL translation:
(1) disjointness assumption: all the classes are to be assumed pairwise disjoint if not specified otherwise; and (2) covering assumption: the content of every class must correspond to the union of its immediate subclasses (this includes the assumption that we do not consider anything apart from what is expressed in the model). In this paper we propose two simple procedures to assist modelers with integrating these assumptions into their models, thereby allowing for a more complete translation into DLs.},
  year = {2012},
  journal = {South African Institute for Computer Scientists and Information Technologists (SAICSIT)},
}

OWL 2 DL is a very expressive language and has many fea- tures for declaring complex object property expressions. Standard rea- soning services for OWL ontologies assume the axioms in the ‘object property box’ to be correct and according to the ontologist’s intention. However, the more one can do, the higher the chance modelling flaws are introduced; hence, an unexpected or undesired classification or inconsis- tency may actually be due to a mistake in the object property box, not the class axioms. We identify the types of flaws that can occur in the object property box and propose corresponding compatibility services, SubProS and ProChainS, that check for meaningful property hierarchies and property chaining and propose how to revise a flaw. SubProS and ProChainS were evaluated with several ontologies, demonstrating they indeed do serve to isolate flaws and can propose useful corrections.

@{6,
  author = {Maria Keet},
  title = {Detecting and Revising Flaws in OWL Object Property Expressions},
  abstract = {OWL 2 DL is a very expressive language and has many fea- tures for declaring complex object property expressions. Standard rea- soning services for OWL ontologies assume the axioms in the ‘object property box’ to be correct and according to the ontologist’s intention. However, the more one can do, the higher the chance modelling flaws are introduced; hence, an unexpected or undesired classification or inconsis- tency may actually be due to a mistake in the object property box, not the class axioms. We identify the types of flaws that can occur in the object property box and propose corresponding compatibility services, SubProS and ProChainS, that check for meaningful property hierarchies and property chaining and propose how to revise a flaw. SubProS and ProChainS were evaluated with several ontologies, demonstrating they indeed do serve to isolate flaws and can propose useful corrections.},
  year = {2012},
  journal = {18th International Conference on Knowledge Engineering and Knowledge Management (EKAW'12), A. ten Teije et al. (Eds.). Oct 8-12, Galway, Ireland. Lecture Notes in Artificial Intelligence LNAI 7603},
}