Case Studies |
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We have tested the MIDAS prototype in various example scenarios: |
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The News Discovery Assistant |
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We have tested MIDAS in the design and implementation of
a News Discovery Assistant (NDA) that enables mobile users
to access information services available on the wired Internet,
such as newspaper reading services and radio/television digital
broadcasting services. | |||
Deployment Setting
We have deployed our MIDAS prototype components over a metropolitan area network composed of a fixed computing infrastructure and devices connected via IEEE 802.11 Access Points (APs),
which may be located at the airport, at the railway station, in a shopping mall or in other public places.
NDA Setup
Client-side applications enable users to subscribe to NDA by filling in
a form with user profile and to authenticate themselves to
the service before starting any NDA session.
Let us suppose that Alice, while waiting for her train at the
railway station, is willing to access a news service using her
802.11b enabled palmtop. In particular, Alice would like to
download today’s sport news from available newspapers so
that she can read them during her journey. Metadata Specification For the sake of simplicity, in this case study we have only considered static profile data, hence services are searched directly within discovery scope.
Hint: To better visualize the ontologies, you might use the Protégé Ontology Editor by selecting the option: Build an OWL project from existing sources. | |||
The Zefiro Prototype |
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The MIDAS prototype has been deployed in a harbour scenario in the framework of the national Zefiro research project.
In particular, here we describe how MIDAS components interwork during an example of user discovery session where Bob accesses services
from a resource-limited device while on board of his docked boat. | |||
Deployment Setting
We have deployed our MIDAS prototype components over both a fixed harbour computing infrastructure and devices on boats connected via IEEE 802.11 Access Points (APs).
Each AP defines its network locality that includes service/information points on local wired hosts and mobile wireless devices, playing the role of service clients or providers, within the AP coverage area. Metadata Specification
Service profiles are specified with the MIDAS Profile ontologies.
In addition, we have created a testbed service ontology. The requirement/capabilities ontology is derived from the UNSPSC standard taxonomy.
In particular, we have developed a "Travel, Food, Lodging and Entertainment" ontology that is derived from the corresponding UNSPSPC taxonomy (starting from code 90.00.00.00).
The Zefiro Offer ontology defines a capability for each instance defined in the TFLE Ontology and some example services exhibiting each one capability. Discovery Scope and Service View Creation
After docking his boat, Bob starts a discovery session. The stub on his device triggers MIDAS to generate a companion proxy, running on the fixed network infrastructure and possibly migrating to maintain co-locality with Bob.
The proxy maintains a copy of user/device profiles and generates its MM, CM, DM, and QPM instances. Discovery Scope and Service View Update
Let us suppose that another boat, e.g., Greg’s yacht, is approaching the harbour with an on-board PC providing additional services, such as a shared repository offering high-resolution pictures and a blackboard service with indications/suggestions about visited bays. |
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Last updated 16-02-2006 |