Browsing by Author "Tansel, Abdullah Uz"

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    A comparison of historical relational query languages
    (ASME, 1994-07) Tansel, Abdullah Uz; Tin, E.
    We introduce a historical relational data model in which N1NF relations are used and 1-level of nesting is allowed. Attributes can either be atomic or temporal atom. An atomic attribute represents a time invariant attribute. A temporal atom consists of two components, a value and a temporal set, which is a set of times denoting the validity period of the value. We define a relational tuple calculus for this model. We follow a comparative approach towards completeness of historical query languages.
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    Frequent itemset mining, and association rules
    (IGI Global, 2005) Imberman, S.; Tansel, Abdullah Uz
    With the advent of mass storage devices, databases have become larger and larger. Point-of-sale data, patient medical data, scientific data, and credit card transactions are just a few sources of the ever-increasing amounts of data. These large datasets provide a rich source of useful information. Knowledge Discovery in Databases (KDD) is a paradigm for the analysis of these large datasets. KDD uses various methods from such diverse fields as machine learning, artificial intelligence, pattern recognition, database management and design, statistics, expert systems, and data visualization.
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    Modeling and querying temporal data
    (IGI Global, 2005) Tansel, Abdullah Uz; Rivero, L. C.; Doorn, J. H.; Ferraggine, V. E.
    The paper discusses modelling temporal variation of data in the context of the relational data model. This is done by employing time-stamps, which leads to two possible approaches: adding time-stamps to tuples and using first normal-form (1NF) relations, and adding time-stamps to attributes and using non-first normal form (NINF) relations. Modelling temporal data according to each approach with their respective data-manipulation operations are covered. This is followed by a discussion that includes the advantages and expressive power of each approach, the classification of temporal databases, and the handling of retroactive and postactive changes.
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    Temporality in databases
    (Springer, Berlin, Heidelberg, 2004) Tansel, Abdullah Uz
    Temporality, or the time dimension is an essential aspect of the reality databases attempt to model and keep data about. However, in many database applications temporal data is treated in a rather ad hoc manner in spite of the fact that temporality should be an integral part of any data model. In this presentation we will address issues peculiar to temporal data and explore how we can add a temporal dimension to databases. We will specifically focus our attention on the relational data model and the object relational systems for managing temporal data since these systems are widely available and they are also widely used.