[Nets-seminars] Guest speaker 13:00 Friday 29th July
Richard G. Clegg
richard at richardclegg.org
Tue Jul 26 16:25:50 BST 2011
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.
Jacqueleen Joubran -- Near Real Time Automated Generalization for Mobile
Devices
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.
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.
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.
--
Richard G. Clegg,
Dept of Elec. Eng.,
University College London
http://www.richardclegg.org/
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