Current governmental applications are of large scale and always compute-intensive and data-intensive, and we focus on
introducing P2P computing to facilitate loose coupled governmental applications in this paper. As GIS data is always
deposited in locationally distributed nodes, which are probably administrated under spatial databases, the global range is
divided into regions to eliminate complicated consistency maintenance and unnecessary message exchanging, and
hierarchical spatial indexes are designed for efficient locating spatial resources and low control cost. When executing, a
user submitted global spatial query are firstly parsed to sequential subtasks refer to distributed spatial index, and then
dynamically passed to appropriate nodes and cooperatively accomplished. Nodes intercommunicate by cooperating
messages, which are sent directly to the destination. Besides collaboration process of sequential execution, a dynamic
alternative participant approach for failure handling of the sequential execution is provided, which saves the expensive
rollback or abort. And this paper also designed and implemented a p2p based loose governmental application prototype,
in which nodes intercommunicate via p2p network sub layer, also a user interface is implemented to manage the request
from user and eventually reply a result.
The management of network constrained moving objects is more and more practical, especially in intelligent
transportation system. In the past, the location information of moving objects on network is collected by GPS, which cost
high and has the problem of frequent update and privacy. The RFID (Radio Frequency IDentification) devices are used
more and more widely to collect the location information. They are cheaper and have less update. And they interfere in
the privacy less. They detect the id of the object and the time when moving object passed by the node of the network.
They don't detect the objects' exact movement in side the edge, which lead to a problem of uncertainty. How to
modeling and query the uncertainty of the network constrained moving objects based on RFID data becomes a research
issue. In this paper, a model is proposed to describe the uncertainty of network constrained moving objects. A two level
index is presented to provide efficient access to the network and the data of movement. The processing of imprecise
time-slice query and spatio-temporal range query are studied in this paper. The processing includes four steps: spatial
filter, spatial refinement, temporal filter and probability calculation. Finally, some experiments are done based on the
simulated data. In the experiments the performance of the index is studied. The precision and recall of the result set are
defined. And how the query arguments affect the precision and recall of the result set is also discussed.
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