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We have a visitor to the EE department on Friday 29th July who will
be giving us a talk at 13:00, all welcome. The talk will be held in
the Barlow Room.<br>
<br>
<style type="text/css">p { margin-bottom: 0.21cm; </style><font
size="3">Jacqueleen
Joubran -- Near Real Time Automated Generalization for Mobile
Devices<br>
<br>
The substantial amount of geospatial data in the form of digital
maps which is available on the World-Wide Web, together with the
increasing number mobile devices, motivates the development of
modern techniques suitable to performing near real time
applications on mobile devices. In this sense, geo-spatial
applications are becoming a major goal to developing techniques
and algorithms. One of these applications is the need to present
spatial data in different resolutions and scales in real time. A
customary approach in the last years to solving the varying map
scale presentation was by applying a Multiple
Representation/Resolution Database approach in order to prepare in
advance digital maps at different scales, as generalizing the
geospatial data is a time consuming process. Moreover, Multiple
Representation/Resolution Database approach requires a complex
updating process as all predefined maps in the different levels
(scales) should be updated simultaneously. <br>
<br>
A new pseudo-physical model for a real time cartographic
generalization is introduced. The aim is to provide specific maps
in real time for mobile devices while responding to the needs of
the different users with their different interests to viewing the
geospatial information.<br>
<br>
The pseudo-physical model described is employed the electric field
theory to understand and describe the action and behaviour of
active objects in the automated digital map generalization
process. The developed model defines several parameters that
determine for each object a relative importance "power" in the map
in real time according to the user needs, and set rules to control
the mutual interaction forces between these powers in order to
compromise between the constraints and solve the competition
between the objects on the limited map area at a reduced scale.
The parameters are different from cartographic purposes and they
depend on the user requirements (the map target, and the map scale
and resolution). Each object acts according to its relative
importance calculated as its "power", computed as a function of
its properties and these parameters. Interactions between map
objects are expressed by actions of the forces constructed around
the graphics presentation limitations and affected by several
parameters depending on the presented object and the properties of
the surrounding objects. As a result, the surrounding objects
affect and cause the “weak” objects to change their shape, size or
place. The computer digital implementation of this new method
requires spatial data mining of the huge databases in order to
define the implicit attributes and connections between the
presented map objects and to visualise the relevant data on the
websites and mobile devices screen, all in near real time computer
algorithm. <br>
</font>
<pre class="moz-signature" cols="72">--
Richard G. Clegg,
Dept of Elec. Eng.,
University College London
<a class="moz-txt-link-freetext" href="http://www.richardclegg.org/">http://www.richardclegg.org/</a>
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