My presentation at the ISWC Doctoral Consortium 2013

1. Dipartimento di
Elettronica, Informazione e
Bioingegneria
Daniele Dell’Aglio
Advisor: Emanuele Della Valle
Ontology-based top-k query
answering over massive,
heterogeneous, and dynamic data

2. 2/8
D. Dell'Aglio. Ontology-based top-k continuous query
answering.
Relevancy
 The processing of multiple streams poses challenges,
such as:
Data velocity
Data in multiple sources
Data heterogeneity
Identification of
relevant information
• During the Milano Design Week: given the data from
Twitter, Foursquare and public transportations, which are
the most attractive locations now?
22 October, 2013
Dipartimento di Elettronica,
Informazione e Bioingegneria

3. D. Dell'Aglio. Ontology-based top-k continuous query
answering.
Related works
Data velocity:
Stream processing
22 October, 2013
3/8
Data hetereogeneity:
Ontologies / Stream Reasoning
Relevant information:
Top-k queries
Dipartimento di Elettronica,
Informazione e Bioingegneria

4. 4/8
D. Dell'Aglio. Ontology-based top-k continuous query
answering.
Problem statement
 In a real-time context, we want to make
continuous queries (with a subset of top-k
ones) using an ontology describing the data
model
 Problem statement: investigate how the top-k
queries and the ontology can be exploited to
improve the continuous query answering process
 The order is a central element in both Stream
Reasoning and top-k queries
– If and how can it be used to improve the query
answering process?
22 October, 2013
Dipartimento di Elettronica,
Informazione e Bioingegneria

5. 5/8
D. Dell'Aglio. Ontology-based top-k continuous query
answering.
Research questions
How can M and K be
used to optimize the
logical plans?
Logical
Logical
Plans
Logical
Plans
Plans
Physical
Physical
Plans
Physical
Plans
Plans
How do M and K can be
exploited to do cross-query
optimizations?
22 October, 2013
How can M and K be used
to optimize the physical
plans?
Dipartimento di Elettronica,
Informazione e Bioingegneria

6. 6/8
D. Dell'Aglio. Ontology-based top-k continuous query
answering.
Plan
State of the art analysis
DSMS
/CEP
Definition of the evaluation
framework
Investigation of Stream Reasoning
Top-k
queries
Reasoning
Investigation of Stream Reasoning
+ Top-k
22 October, 2013
Dipartimento di Elettronica,
Informazione e Bioingegneria

7. 7/8
D. Dell'Aglio. Ontology-based top-k continuous query
answering.
Evaluation plan
 Correctness: assess how the techniques affect
the correctness
– Soundness
– Completeness
 Performance: compare the time and memory
consumption w.r.t state of the art solutions
 Use case and exploitation
– Determine what is possible to do
with state of the art solutions
– Identification of use cases to apply research results
22 October, 2013
Dipartimento di Elettronica,
Informazione e Bioingegneria

8. 8/8
D. Dell'Aglio. Ontology-based top-k continuous query
answering.
Preliminary results
 CSRbench
– Extension of SRbench to assess correctness of RDF
stream processors
– Three elements
• Model to describe the operational semantics
• Test set
• Automatic validator
 Twindex FuoriSalone
– Social media analytics to real-time monitor the
FuoriSalone event
• What do people think about a given event?
• Which are the most attractive events at the
moment?
22 October, 2013
Dipartimento di Elettronica,
Informazione e Bioingegneria

9. 9/8
D. Dell'Aglio. Ontology-based top-k continuous query
answering.
Thank you! Questions?
Ontology-based top-k query answering over
massive, heterogeneous, and dynamic data
Daniele Dell’Aglio
Advisor: Emanuele Della Valle
22 October, 2013
Dipartimento di Elettronica,
Informazione e Bioingegneria