New Dimension in Relational Database Preservation

Due to the expansion and growth of information technologies, much of human knowledge is now recorded on digital media. A new problem in the digital universe has arisen: Digital Preservation. This chapter addresses the problems of Digital Preservation and focuses on the conceptual model within a specific class of digital objects: Relational Databases. Previously, a neutral format was adopted to pursue the goal of platform independence and to achieve a standard format in the digital preservation of relational databases, both data and structure (logical model). The authors address the preservation of relational databases by focusing on the conceptual model of the database, considering the database semantics as an important preservation “property.” For the representation of this higher layer of abstraction present in databases, they use an ontology-based approach. At this higher abstraction level exists inherent Knowledge associated to the database semantics that the authors tentatively represent using “Web Ontology Language” (OWL). From the initial prototype, they develop a framework (supported by case studies) and establish a mapping algorithm for the conversion between databases and OWL. The ontology approach is adopted to formalize the knowledge associated to the conceptual model of the database and also a methodology to create an abstract representation of it. The system is based on the functional axes (ingestion, administration, dissemination, and preservation) of the OAIS reference model.

GuessXQ

XML is a widely used general-purpose annotation formalism for creating custom markup languages. XML annotations give structure to plain documents to interpret their content. To extract information from XML documents XPath and XQuery languages can be used. However, the learning of these dialects requires a considerable effort. In this context, the traditional Query-By-Example methodology (for Relational Databases) can be an important contribution to leverage this learning process, freeing the user from knowing the specific query language details or even the document structure. This chapter describes how to apply the Query-By-Example concept in a Web-application for information retrieval from XML documents, the GuessXQ system. This engine is capable of deducing, from an example, the respective XQuery statement. The example consists of marking the desired components directly on a sample document, picked-up from a collection. After inferring the corresponding query, GuessXQ applies it to the collection to obtain the desired result.

An Example-Based Generator of XSLT Programs

XSLT is a powerful and widely used language for transforming XML documents. However, its power and complexity can be overwhelming for novice or infrequent users, many of whom simply give up on using this language. On the other hand, many XSLT programs of practical use are simple enough to be automatically inferred from examples of source and target documents. An inferred XSLT program is seldom adequate for production usage but can be used as a skeleton of the final program, or at least as scaffolding in the process of coding it. It should be noted that the authors do not claim that XSLT programs, in general, can be inferred from examples. The aim of Vishnu—the XSLT generator engine described in this chapter—is to produce XSLT programs for processing documents similar to the given examples and with enough readability to be easily understood by a programmer not familiar with the language. The architecture of Vishnu is composed by a graphical editor and a programming engine. In this chapter, the authors focus on the editor as a GWT Web application where the programmer loads and edits document examples and pairs their content using graphical primitives. The programming engine receives the data collected by the editor and produces an XSLT program.

A Secure and Dynamic Mobile Identity Wallet Authorization Architecture Based on a XMPP Messaging Infrastructure

In this chapter, the authors propose and describe an identity management framework that allows users to asynchronously control and effectively share sensitive dynamic data, thus guaranteeing security and privacy in a simple and transparent way. Their approach is realised by a fully secure mobile identity digital wallet, running on mobile devices (Android devices), where users can exercise discretionary control over the access to sensitive dynamic attributes, disclosing their value only to pre-authenticated and authorised users for determined periods of time. For that, the authors rely on an adaptation of the OAuth protocol to authorise and secure the disclosure of personal-private user data by the usage of token exchange and new XML Schemas to establish secure authorisation and disclosure of a set of supported dynamic data types that are being maintained by the personal mobile digital wallet. The communication infrastructure is fully implemented over the XMPP instant messaging protocol and is completely compatible with the public XMPP large messaging infrastructures already deployed on the Internet for real time XML document interchange.

Using Semantics in XML Information Access

This chapter presents an ongoing work in the context of the Portuguese Emigration Museum about information access in XML collections associated with semantic information. The museum asset is made up of documents of more than 8 kinds, ranging from passport records to photos/cards and building-drawings. In this chapter, the authors discuss the approach used to create the exhibition rooms of the virtual Web-based museum. Each room consists of the information contained in those single or interrelated resources. The information exhibited in each room is described by an ontology, written in OWL. The authors also discuss the approach used to take advantage of a combination of structural and semantic information to efficiently retrieve documents from the MEC collection. Both approaches can be automatised to allow a very systematic way to deal with the huge and rich museum assets.

MCEQLS Approach in Multi-Criteria Evaluation of Quality of Learning Repositories

This chapter analyzes the quality of XML learning object repositories. Special attention is paid to the models and methods to evaluate the quality of learning repositories. Multiple criteria decision analysis and optimization methods are explored to be applied for evaluating the quality of learning repositories. This chapter also presents the results of several large-scale projects co-funded by EU research programs that have been implemented in the area of learning repositories. Learning repositories’ technological quality model (system of criteria) and novel comprehensive model for evaluating the quality of user interfaces of learning repositories are presented in more detail. The general MCEQLS (Multiple Criteria Evaluation of Learning Software) approach is presented in this chapter. It is shown that the MCEQLS approach is suitable for evaluating the quality of learning repositories. The author believes that research results presented in the chapter will be useful for all educational stakeholder groups interested in developing learning repositories.

On Quality Assessment of Learning Technology Specifications

Specifications can be considered “hidden” technology: they are deployed in tools and applications without being directly visible. This poses a challenge regarding quality assessment of this type of technology. This chapter describes a framework for quality assessment of learning technology specifications and how it was used to evaluate and improve a case in point: the Learning Path Specification. However, although the importance of raising the quality of a specification is beyond question, this in itself is no guarantee for its (wider) adoption. The final section of this chapter discusses how quality assessment of the Learning Path Specification at best informs us on its chances of gaining adoption, but by no means suffices to establish it. For this discussion, the authors draw on Rogers’s work regarding five perceived characteristics of innovations influencing their diffusion: relative advantage, compatibility, complexity, triability, and observability.

Making Programming Exercises Interoperable with PExIL

Several standards have appeared in recent years to formalize the metadata of learning objects, but they are still insufficient to fully describe a specialized domain. In particular, the programming exercise domain requires interdependent resources (e.g. test cases, solution programs, exercise description) usually processed by different services in the programming exercise lifecycle. Moreover, the manual creation of these resources is time-consuming and error-prone, leading to an obstacle to the fast development of programming exercises of good quality. This chapter focuses on the definition of an XML dialect called PExIL (Programming Exercises Interoperability Language). The aim of PExIL is to consolidate all the data required in the programming exercise lifecycle from when it is created to when it is graded, covering also the resolution, the evaluation, and the feedback. The authors introduce the XML Schema used to formalize the relevant data of the programming exercise lifecycle. The validation of this approach is made through the evaluation of the usefulness and expressiveness of the PExIL definition. In the former, the authors present the tools that consume the PExIL definition to automatically generate the specialized resources. In the latter, they use the PExIL definition to capture all the constraints of a set of programming exercises stored in a learning objects repository.

Preservation of Data Warehouses

Data warehouses are used in many application domains, and there is no established method for their preservation. A data warehouse can be implemented in multidimensional structures or in relational databases that represent the dimensional model concepts in the relational model. The focus of this work is on describing the dimensional model of a data warehouse and migrating it to an XML model, in order to achieve a long-term preservation format. This chapter presents the definition of the XML structure that extends the SIARD format used for the description and archive of relational databases, enriching it with a layer of metadata for the data warehouse components. Data Warehouse Extensible Markup Language (DWXML) is the XML language proposed to describe the data warehouse. An application that combines the SIARD format and the DWXML metadata layer supports the XML language and helps to acquire the relevant metadata for the warehouse and to build the archival format.

Using Device Detection Techniques in M-Learning Scenarios

Recent studies of mobile Web trends show the continued explosion of mobile-friend content. However, the wide number and heterogeneity of mobile devices poses several challenges for Web programmers, who want automatic delivery of context and adaptation of the content to mobile devices. Hence, the device detection phase assumes an important role in this process. In this chapter, the authors compare the most used approaches for mobile device detection. Based on this study, they present an architecture for detecting and delivering uniform m-Learning content to students in a Higher School. The authors focus mainly on the XML device capabilities repository and on the REST API Web Service for dealing with device data. In the former, the authors detail the respective capabilities schema and present a new caching approach. In the latter, they present an extension of the current API for dealing with it. Finally, the authors validate their approach by presenting the overall data and statistics collected through the Google Analytics service, in order to better understand the adherence to the mobile Web interface, its evolution over time, and the main weaknesses.