Automatické mapování ontologií a zpracování neurčitosti

ocelotgiantΤεχνίτη Νοημοσύνη και Ρομποτική

7 Νοε 2013 (πριν από 3 χρόνια και 7 μήνες)

93 εμφανίσεις

12th of October, 2006

KEG seminar

1

Combining Ontology Mapping
Methods Using Bayesian
Networks

Ontology Alignment
Evaluation Initiative 2006
-

'Conference' Track


Ondřej Šváb

Vojtěch Svátek

12th of October, 2006

KEG seminar

2

Overview


Ontology Mapping


Combining Ontology Mapping Methods


Using Bayesian Networks


String distance metrics


Mapping patterns


OAEI


Our track


conference domain


Evaluation


12th of October, 2006

KEG seminar

3

Ontology Mapping

Ontology Mapping = discovering
of Semantic correspondencies
(equivalence, subsumption)

12th of October, 2006

KEG seminar

4

Classification of ontology mapping
techniques

12th of October, 2006

KEG seminar

5

Model
ling of interdependencies (1)


Using Bayesian Networks


String distance metrics from SecondString
library (mapping methods)


Training data, pairs of concepts from ontologies
ekaw.owl a confOf.owl from OntoFarm collection


798 pairs


Bayesian network


nodes: mapping justification by each mapping method


Classification node: „align“ (true, false)

12th of October, 2006

KEG seminar

6

Model
ling of interdependencies (2)


Two tested Bayesian Networks (two
corresponding classifiers)


Naive Bayesian Structure


Probability distributions learned from data


Learned Bayesian Structure


Learned both CPT and structure


12th of October, 2006

KEG seminar

7

Evaluation of models


One
-
leave
-
out method (798x)


Evaluation: precision, recall




Precision more important than recall


3:2 (precision weight 0,6), 4:1 (0,8)


C = P*a + R*b, kde a, b jsou váhy


higher C, better classifier

12th of October, 2006

KEG seminar

8

73
% p
recision, 60
%
recall, 88
%
accuracy



at 80
%
threshold

12th of October, 2006

KEG seminar

9

84
% p
recision, 53
%
recall, 89
%
accuracy



at 60
%
threshold

Align ci. CharJaccard, Monge
-
Elkan, Levenshtein
| TFIDF,

SmithWaterman, Jaccard, Jaro, SLIM

12th of October, 2006

KEG seminar

10

Evaluation (c = P*a + R*b)

Naive bayes

Jaccard

BN 2

12th of October, 2006

KEG seminar

11

Mapping patterns (1)


Capturing structures using mapping
patterns


Mapping pattern between ontologies


12th of October, 2006

KEG seminar

12

Mapping patterns (2)

Mapping pattern

Part of Bayesian Network

12th of October, 2006

KEG seminar

13

Conclusions
& Future works


Combination of string
-
based methods is not promising


Implementation of low
-
level

string based justifications

of mapping



suffix, prefix,
identical names


Capturing context



Employ
met
ho
d
s

working with

structures

of ontologies

(gra
ph
-
based
), map
ping patterns


Not only equivalence relations, but also discovery
subsumption relations


using
ling
uistic sources, like
WordNet

12th of October, 2006

KEG seminar

14

Ontology Alignment
Evaluation Initiative 2006
-

'Conference' Track

12th of October, 2006

KEG seminar

15

OAEI 2006 at ISWC

06


Evaluation initiative in Ontology matching


Since 2004


In 2006 OAEI workshop at Ontology matching
workshop, ISWC


Four tracks (six data sets)


Benchmark (biblio),


Expressive ontologies: anatomy (2 ontologies 10k
classes), jobs (jobs and jobs seekers, real world
case)


Directory (web sites directory)


4 thousand
elementary test, Food data set


SKOS thesaurus
about food with other food ontologies



12th of October, 2006

KEG seminar

16

Conference track


Coordinated by UEP


Free exploration by participants within 10
ontologies


Domain: conference organisation


No a priori reference alignment


Participants: 6 research groups

12th of October, 2006

KEG seminar

17

Ontologies in track

12th of October, 2006

KEG seminar

18

Participants (1)


Combination of methods: lexicographic and contextual


ISLab


1:1 matching approach


Linguistic technique
-

thesaurus of terms and weighted
terminological relationships is exploited


Contextual technique
-

semantic relation in an ontology


RiMOM


Ontology alignment defined as a directional one


Matchers: Name
-
based (also NLP methods), Instance
-
based,
Description
-
based, Taxonomy context
-
based, Constraints
-
based


CtxMatch


DL formulas


Not only eq., also subsumption, disjointness, intersection

12th of October, 2006

KEG seminar

19

Participants (2)


COMA++


Extension of COMA


Automs


Lexical matching method, LSI, structural
matching algorithm


Falcon


elementary matchers: string
-
based, graph
-
based


12th of October, 2006

KEG seminar

20

Evaluation (1)


Personal judgement of organisers


interesting individual correspondences

(inverse compound names, eg.
PC_Member = Member_PC), synonyms


Mapping errors:
subsumption
,
inversion
role
,
siblings
,
lexical confusion



Mapping between relation and class, eg.
has_an_email and E
-
mail

12th of October, 2006

KEG seminar

21

Evaluation (2)

12th of October, 2006

KEG seminar

22

Evaluation (3)


Subsumption error


Author,Paper_Author


Conference_Trip, Conference_part


Inversion role error


abstract_of_paper,reviewerOfPaper error


Siblings


ProgramCommittee,Technical_commitee


Lexical confusion error


program,Program_chair


Relation


Class mapping


has_enddate,Date


hasTitle,Title; hasSurname,Surname




12th of October, 2006

KEG seminar

23

Evaluation (4)

12th of October, 2006

KEG seminar

24

Summary


How to evaluate this track?


Interesting mappings


Recall?