Denise de Vries

Reduce, reuse, recycle: practical approaches to schema integration, evolution and versioning

Three themes are apparent in recent schema integration, evolution and versioning research. First, the need to reduce the number of schema changes that are necessary. The approach here has been to build into the conceptual and data models the scope to accommodate modest changes to definition. Second, research that aims to reuse the current schema definition through procedures that mask the changes through sophisticated wrappers or techniques for multiple extensional data. Finally, techniques that enable schema change to be accommodated as seamlessly and as painlessly as possible. All these approaches have their limitations and strengths. This paper investigates each of these approaches and outlines the current research directions in schema integration, evolution and versioning.

The case for mesodata: An empirical investigation of an evolving database system

Database evolution can be considered a combination of schema evolution, in which the structure evolves with the addition and deletion of attributes and relations, together with domain evolution in which an attributes specification, semantics and/or range of allowable values changes. We present the results of an empirical investigation of the evolution of a commercial database system that measures and delineates between changes to the database that are (a) structural and (b) attribute domain related. We also estimate the impact that modelling using the mesodata approach would have on the evolving system.

Facilitating Database Attribute Domain Evolution Using Mesodata

Database evolution can be considered a combination ofschema evolution, in which the structure evolves with the addition and deletion of attributes and relations, together with domain evolution in which an attribute’s specification, semantics and/or range of allowable values changes. We present a model in which mesodata – an additional domain definition layer containing domain structure and intelligence – is used to alleviate and in some cases obviate the need for data conversion or coercion. We present the nature and use of mesodata as it affects domain evolution, such as when a domain changes, when the semantics of a domain alter and when the attribute’s specification is modified.

A multi-level framework for the analysis of sequential data

Traditionally text mining has had a strong link with information retrieval and classification and has largely aimed to classify documents according to embedded knowledge. Association rule mining and sequence mining, on the other hand, have had a different goal; one of eliciting relationships within or about the data being mined. Recently there has been research conducted using sequence mining techniques on digital document collections by treating the text as sequential data. In this paper we propose a multi-level framework that is applicable to text analysis and that improves the knowledge discovery process by finding additional or hitherto unknown relationships within the data being mined. We believe that this can lead to the detection or fine tuning of the context of documents under consideration and may lead to a more informed classification of those documents. Moreover, since we use a semantic map at varying stages in the framework, we are able to impose a greater degree of focus and therefore a greater transitivity of semantic relatedness that facilitates the improvement in the knowledge discovery process.

Postponing schema definition: low instance-to-entity ratio (LItER) modelling

There are four classes of information system that are not well served by current modelling techniques. First, there are systems for which the number of instances for each entity is relatively low resulting in data definition taking a disproportionate amount of effort. Second, there are systems where the storage of data and the retrieval of information must take priority over the full definition of a schema describing that data. Third, there are those that undergo regular structural change and are thus subject to information loss as a result of changes to the schemas information capacity. Finally, there are those systems where the structure of the information is only partially known or for which there are multiple, perhaps contradictory, competing hypotheses as to the underlying structure. This paper presents the Low Instance-to-Entity Ratio (LItER) Model, which attempts to circumvent some of the problems encountered by these types of application. The two-part LItER modelling process possesses an overarching architecture which provides hypothesis, knowledge base and ontology support together with a common conceptual schema. This allows data to be stored immediately and for a more refined conceptual schema to be developed later. It also facilitates later translation to EER, ORM and UML models and the use of (a form of) SQL. Moreover, an additional benefit of the model is that it provides a partial solution to a number of outstanding issues in current conceptual modelling systems.

Accommodating mesodata into conceptual modelling methodologies

Mesodata modelling is a recently developed approach for enhancing a data models capabilities by providing for more advanced semantics to be associated with the domain of an attribute. Mesodata supplies both an inter-value structure to the domain and a set of operations applicable to that structure that may be used to facilitate additional functionality in a database. We argue that conceptual modelling methodologies would be semantically richer if they were able to express the semantics of complex data types for attribute domains. This paper investigates the accommodation of mesodata into the entity-relationship and object role modelling, presenting the Mesodata Entity-Relationship (MDER) model and Mesodata Object Role Modelling (MDORM), which show how the mesodata concept can be incorporated into conceptual modelling methodologies to include the semantics of complex-domain structures.

Mobile Learning Adoption in Developing Countries

Mobile devices have become attractive learning devices. They provide learners with flexibility and ubiquity to learn anytime and anywhere via wireless Internet. The majority of the existing research on mobile learning adoption has focused primarily on developed countries, with developing countries being largely underexplored. However, the high mobile phone penetration rates in developing countries have provided important opportunities for broadening access to mobile learning in those societies. This paper provides insights into mobile learning adoption in developing countries. It uncovers key issues including the role of social influences, culture, expectations around effort and performance and how the use of M-learning can contribute to innovation skills which are pertinent for the future. It offers valuable implications to educators in developing communities.

Creating Disk Images of Born Digital Content: A Case Study Comparing Success Rates of Institutional Versus Private Collections

ABSTRACT Although libraries maintain collections of material on computer disks in climate controlled environments, a significant amount of digital heritage is in private collections. In this study we compared the outcomes of creating disk images of the State Library of South Australia’s born digital collections with those of a private collector to gauge the effect of long term storage conditions. The failure rates of both collections give cause for concern, and the results from the private collection are alarming.

A Structural Equation Model (SEM) of Governing Factors Influencing the Implementation of T-Government

Governments around the world have invested significant sums of money on Information and Communication Technology (ICT) to improve the efficiency and effectiveness of services been provided to their citizens. However, they have not achieved the desired results because of the lack of interoperability between different government entities. Therefore, many governments have started shifting away from the original concept of e-Government towards a much more transformational approach that encompasses the entire relationship between different government departments and users of public services, which can be termed as transformational government (t- Government). In this paper, a model is proposed for governing factors that impact the implementation of t-Government such as strategy, leadership, stakeholders, citizen centricity and funding in the context of Saudi Arabia. Five constructs are hypothesised to be related to the implementation of t-Government. To clarify the relationships among these constructs, a structural equation model (SEM) is utilised to examine the model fit with the five hypotheses. The results show that there are positive and significant relationships among the constructs such as the relationships between strategy and t-Government; the relationships between stakeholders and t-Government; the relationships between leadership and t-Government. This study also showed an insignificant relationship between citizens’ centricity and t-Government and also an insignificant relationship between funding and t-Government. document is a “live” template and already defines the components of your paper [title, text, heads, etc.] in its style sheet.

A Tool for Evaluating, Adapting and Extending Game Progression Planning for Diverse Game Genres

Game progression design is a demanding, data-intensive design activity that is typically performed by game designers without even basic computational support. To address this, a concept for tool-supported “progression planning” has been proposed and implemented by Butler, Smith, Liu & Popovic for the design of their educational puzzle game Refraction. Refraction is a game that has relatively undemanding progression design needs. Further tool development and practice-based evaluation is needed to establish whether– and if so, how– a generic, tool-supported progression design process can address the diverse range of often complex progression design challenges that game designers find themselves engaging with. In this paper we describe how we used three game design case studies in contrasting game genres to inform the development of a tool that adapts and extends the progression planning approach.