6 research outputs found
A Quadtree-Based Dynamic Attribute Indexing Method
Dynamic attributes are attributes that change continuously over time making it impractical to issue explicit updates for every change. In this paper, we adapt a variant of the quadtree structure to solve the problem of indexing dynamic attributes. The approach is based on the key idea of using a linear function of time for each dynamic attribute that allows us to predict its value in the future. We contribute an algorithm for regenerating the quadtree-based index periodically that minimizes CPU and disk access cost. We also provide an experimental study of performance focusing on query processing and index update overheads
Multi-scale data storage schemes for spatial information systems
This thesis documents a research project that has led to the design and prototype
implementation of several data storage schemes suited to the efficient multi-scale
representation of integrated spatial data. Spatial information systems will benefit from
having data models which allow for data to be viewed and analysed at various levels
of detail, while the integration of data from different sources will lead to a more
accurate representation of reality.
The work has addressed two specific problems. The first concerns the design of an
integrated multi-scale data model suited for use within Geographical Information
Systems. This has led to the development of two data models, each of which allow for
the integration of terrain data and topographic data at multiple levels of detail. The
models are based on a combination of adapted versions of three previous data
structures, namely, the constrained Delaunay pyramid, the line generalisation tree and
the fixed grid.
The second specific problem addressed in this thesis has been the development of an
integrated multi-scale 3-D geological data model, for use within a Geoscientific
Information System. This has resulted in a data storage scheme which enables the
integration of terrain data, geological outcrop data and borehole data at various levels
of detail.
The thesis also presents details of prototype database implementations of each of the
new data storage schemes. These implementations have served to demonstrate the
feasibility and benefits of an integrated multi-scale approach.
The research has also brought to light some areas that will need further research before
fully functional systems are produced. The final chapter contains, in addition to
conclusions made as a result of the research to date, a summary of some of these areas
that require future work
Design and performance evaluation of indexing methods for dynamic attributes in mobile database management systems
Ankara : Department of Computer Engineering and Information Science and the Institute of Engineering and Science of Bilkent University, 1997.Thesis(Master's) -- Bilkent University, 1997.Includes bibliographical references leaves 99-104.Tayeb, JamelM.S