Modelling Data Warehouses and OLAP Applications by Means of Dialogue Objects

Lewerenz, Jana; Schewe, Klaus‐Dieter; Thalheim, Bernhard

doi:10.1007/3-540-47866-3_24

Cited by 15 publications

(3 citation statements)

References 11 publications

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“…This ASM is of no further relevance for us and thus will be ignored. A third ASM models the OLAP interface on the basis of the idea that datamarts can be represented as extended views [12]. In the previous section we have seen examples illustrating this layered architecture.…”

Section: Data Warehouses and Olap Systems As Asssmentioning

confidence: 99%

“…Since the early days of data warehousing the emphasis has been on the design of a central data warehouse [8,9] using appropriate data models, and the development of corresponding OLAP systems based on views [11,12,24]. An integrated formal approach on the basis of the method of Abstract State Machines [3] emphasizing stepwise refinement has been presented in [27].…”

Section: Introductionmentioning

confidence: 99%

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A service-oriented approach to web warehousing

Schewe²,

Thalheim

et al. 2009

Proceedings of the 11th International Conference on Information Integration and Web-Based Applications &Amp; Services

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Data warehouses integrate and aggregate data from various sources to support decision making within an enterprise. Usually, it is assumed that data are extracted from operational databases used by the enterprise. Web warehousing relaxes this view permitting data sources to be located anywhere on the world-wide web. In this paper we even go one step further and propose that web warehousing should exploit data-intensive web services. For this we adopt the view of the recently introduced model of abstract state services (ASSs). An ASS combines a hidden database layer with an operation-equipped view layer, and can be anything from a simple function to a full-fledged Web Information System, thus provides an abstraction of web services that can be made available for use by other systems, e.g. via the web. We demonstrate how data warehouses and OLAP systems can be considered in a natural way as ASSs, i.e. selected data and functionality of a data warehouse may be made available in the form of a generalised web service, and consequently ASS composition can be used for web warehousing. In order to become workable the model of ASSs has to be extended in a way that allows services to be searched for. For this we propose federations of services together with an ontology that specifies their semantics.

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Section: Data Warehouses and Olap Systems As Asssmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A service-oriented approach to web warehousing

Schewe²,

Thalheim

et al. 2009

Proceedings of the 11th International Conference on Information Integration and Web-Based Applications &Amp; Services

Self Cite

View full text Add to dashboard Cite

show abstract

“…Ref. [32] claims that E/R provides the complete functionality and support necessary for OLAP applications. If so, UML also provides such support.…”

Section: Article In Pressmentioning

confidence: 99%

: a multidimensional conceptual model extending UML

Abelló

Samos

Saltor

2006

Information Systems

131

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Logistics for Learning Objects

Tschiedel

Binemann-Zdanowicz

Thalheim

2005

E-Training Practices for Professional Organizations

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Abstract:The increasing attention paid to the importance of context-awareness of content has contributed to more useable e-Iearning websites. While existing approaches mostly cover static learner characteristics, to date it has been difficult to cover the dynamics of context. E-Iearning content must be delivered in the right doses, at the right moment, and in an appropriate form.Our work presents a storyboarding-based approach for specifying contentintensive websites. E-Iearning sites can be validated with regard to learner context. The practicability of our method is shown upon the e-Iearning project DaMiT. The SiteLang methodology helps overcome the limitations of existing approaches based on pre-dermed, structuring of content. It allows a flexible content generation upon learner context, depending on the dynamics of the learning process.Keywords: Database, Learner Centred Learning, Learning Systems, Modelling INTRODUCTIONMany scientific papers and working group specifications have identified the fundamental insight that a high level of granularity of learning units leads to better user-adaptive systems. One guideline for implementing this is to deal with many different types of units from the same topic. Learners just want the most appropriate content delivered just in time and to the right place and device. They should not be confronted with unnecessary content. Therefore, some services are needed to fulfil the learner's needs. Information logistics can provide acceptable strategies that satisfy the requirements for the delivery of the correct unit of information. The goals of information logistics are readily adapted to the e-cha1lenges of e-Learning. Information logisticsInformation logistics aims to provide optimised information-to serve textually correct and needed information at the right time and place-to users (Lienemann, 2001). The information should always be adapted to the user's preferences and communication facilities. Lienemann explains some principles in information logistics, which are relevant to e-Learning.Several information sources: The user looks for additional or extended information in distributed, correlated content bases. At the moment we restrict this to one database of one domain. Information on the tick: Information at the right time depends on the value of the information and the user's context. The value depends on the deliverable content in the knowledge bases. High value demands a detailed description of the content. Users of an e-Learning system may interact with the system in different roles with special characteristics. This is the primary context for the user. The system has to choose, on demand, what the preferred content for the user at any given moment. Consideration of user preferences:Applications of information logistics must be able to satisfy the individual needs of the users. User needs must be specified for optimal operation and implemented in an explicit and an implicit way. Explicit data, like the preferred presentation style or difficulty, must be treated as g...

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Modelling Data Warehouses and OLAP Applications by Means of Dialogue Objects

Cited by 15 publications

References 11 publications

A service-oriented approach to web warehousing

A service-oriented approach to web warehousing

: a multidimensional conceptual model extending UML

Logistics for Learning Objects

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