Transcript LOD를 말하다! - 닥치고 Linked Data

2014.6.27
김우주
연세대학교 정보산업공학과
목차
I.
빅데이터 시대와 정보의 홍수
II. 빅데이터 활용 사례
III. 빅데이터의 한계와 극복 방안
IV. Linked Data의 구축과 활용
V. LOD 2 - 시맨틱 기술의 미래
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An Instrumented Interconnected World
30 billion RFID
12+ TBs
camera
phones
world
wide
100s of
millions
of GPS
enabled
data every day
? TBs of
of tweet data
every day
tags today
(1.3B in 2005)
4.6
billion
devices
sold
annually
25+ TBs of
2+
billion
log data every
day
76 million smart
meters in 2009…
200M by 2014
people
on the
Web by
end 2011
Information Overflow on the Web
 Growth of the Web
 The amount of information available on the Web grows so fast.
 The February 2014 survey shows there exist at least 920,120,079 sites
(http://news.netcraft.com/archives/category/web-server-survey/).
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Information Overflow on the Web
 The Indexed Web contains at least 19.8 billion pages (Sunday, 02 March,
2014).
 http://www.worldwidewebsize.com/
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빅데이터란?
 빅데이터란? (07/11/2013, European Commission)
 Every minute the world generates 1.7 million billion bytes of data,
equivalent to 360,000 standard DVDs.
 The big data sector is growing at a rate of 40% a year.
 무엇이 빅데이터를 중요하게 하는가?
 Big data is already affecting all areas of the economy.
 Data-driven decision making leads to 5-6% efficiency gains in the
different sectors observed.
 Intelligent processing of data is also essential for addressing societal
challenges.
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IBM의 예측: 2014년 6대 빅데이터 트렌드
 직감보다는 더 분석적인 경영 방식
 Companies will grow increasingly data driven and willing to apply analyticsderived insights to key business operations.
 빅데이터 프라이버시와 보안 문제
 Organizations will make a greater effort to build security, privacy, and
governance policies into their big data processes.
 빅데이터에 대한 투자 확대
 CDO(Chief Data Officer)의 등장
 More organizations will bring a chief data officer (CDO) on board.
 보다 유용한 빅데이터 응용 시스템
 외부 데이터에 대한 관심 증대
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LOD를 말하다!
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구글의 독감 트렌드
 ‘독감’ 관련 검색어 분석을 통한 독감 예보 가능성 확인
 구글 검색 사이트에 사용자가 남긴 검색어의 빈도를 조사, 독감 환자의 분포 및 확산 정보
제공
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샌프란시스코, 범죄 예방 시스템
 과거 범죄 발생 지역과 시각 패턴 분석을 통한 경찰 인력 배치
 과거 발생한 범죄 패턴을 분석하여 후속 범죄 가능성 예측
 과거 데이터에서 범죄자 행동을 분석하여 사건 예방을 위한 해법 제시
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미국 국세청, 탈세 방지 시스템
 빅데이터 분석을 통한 탈세 및 사기 범죄 예방 시스템 구축
 사기 방지 솔루션, 소셜 네트워크 분석, 데이터 통합 및 마이닝 등 활용
 세금 누락 및 불필요한 세금 환급 절감의 효과 발생
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KT, 서울특별시 – 빅데이터 기반
심야버스 노선 정책 지원
 심야버스 노선 결정을 위한 유동인구 분석 및 노선 분석
 서울시의 교통 환경(정류장/전용차로/환승)기반 지역별 최적 정류장 위치를
도출하고 KT의 CDR데이터 기반 심야시간 유동인구 및 목적지 통계를 융합하여
노선 검증
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비씨카드, 점포 평가 서비스
 소상공인 창업 성공률 제고를 위한 상가데이터 및 신용카드거래데이터 기반의
빅데이터 분석
 점포이력, 상권분석, 업종추천 등이 이루어지는 과거현황분석, 추천 업종 또는
사용자 선택 업종 매출예측, 수익예측 등의 서비스 제공
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Information Overflow Problems
 Problems
 How to cover all available information? - Recall
 How to find the relevant information? - Precision
Not data (search), but integration, analysis and
insight, leading to decisions and discovery
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Example Query to Google
 ‘iPad’ 검색 사례
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Information Silo Problem
 Stove-piped Systems and Poor Content Aggregation
Semantic Interoperability
 To cope with the problems mentioned in the preceding slide,
we need Semantic Interoperability.
 Semantics
 “The meaning or the interpretation of a word, sentence, or other
language form.”
 What is Semantic Interoperability?
 “Processing or Integration of resources based on the understanding
what’s intended or expressed by other systems or parties.’’
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Front-endedness?
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What if I want to ...
 Move my content from one place to another?
 RSS ? Not enough
 Aggregate my data
 An open FriendFeed?
 Re-use my Flickr friends on Twitter?
 Invite. Again and again ...
 The Semantic Web and Ontology can help !
 By providing a common framework to interlink data from various
providers in an open way.
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How is it Possible?
 Ontology: Agreement with Common Vocabulary & Domain
Knowledge
 Semantic Annotation: metadata (manual & automatic
metadata extraction)
 Reasoning: semantics enabled search, integration, analysis,
mining, discovery
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Semantic Web Layer Cake
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Three Technical Building Block
 Basic Building Block
 URIs for unambiguous names for resources,
 RDF for common data model for expressing metadata,
 Ontology(OWL) for common vocabularies.
 Semantic Web becomes:
 web of data/things/concepts
• What is a Thing/Concept? It can be anything in the world - a movie, a
person, a disease, a location…
• Machines will be able to understand the concept behind a html page.
• This page is talking about ‘Barack Obama’, He is a ‘Person’ and he is the
‘President of USA’ ?
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Who borrows this Idea?
 Facebook
 Facebook Open Graph Protocol and Graph Search
 Google
 Knowledge Graph
 Twitter
 Real-time Semantic Web with Twitter Annotations
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LOD를 말하다!
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Linked Data
 Building a “Web of Data” to enhance the current Web
 The Linking Open Data (LOD) project:
 http://linkeddata.org/
 Translating existing datasets into RDF and linking them together.
• For example, DBpedia (Wikipedia) and GeoNames, Freebase, BBC
programmes, etc.
 Government data also available as Linked Data
• DATA.gov
• DATA.gov.uk
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The LOD cloud
2007
2008
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The LOD cloud
2008
2009
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Web of Data
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Web of Data (Statistics)
 The size of the Web of Data
 The size of the Web of Data can be estimated based on the data set
statistics that are collected by the LOD community in the ESW wiki.
 According to these statistics, the Web of Data currently consists of
31 billion RDF triples, which are interlinked by around 500 million
RDF inter-links (09/19/2011).
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Types of Linked Data Applications
 Linked Data의 활용 방안
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Semantic Search Engines
 Top 7 Semantic Search Engines as An Alternative to Google
 Kngine
 Hakia
 Kosmix: now is part of @WalmartLabs
 DuckDuckGo
 Evri: specialized for iPad and iPhone
 Powerset: now is part of Bing
 Truevert: focus only on environmental concerns.
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LOD를 말하다!
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LOD2 : What is LOD2?
 LOD2(Linked Open Data)
 LOD2 is the large-scale integrating project co-funded by the
European Commission within the FP7 Information and
Communication Technologies Work Programme.
• Started in September 2010
 Partners
• 14 partners (11 European Country)
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LOD2 : Objectives of LOD2
 LOD2 Project Objectives
 Achieving visualization, deployment, sharing, accessibility for linked
open data by software technology.
• Increase visibility of Linked Data activities [Visualization]
• Support deployment Linked Data components [Deployment]
• Improve information sharing between Linked Data components so that
publishing Linked Data is eased. [Sharing]
• Improve access to the content: the online Linked Open Data [Accessibility]
• Improve the software technology which support it [By software
technology]
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LOD2 Stack : Overview
 LOD2 Stack
 LOD2 project provides LOD2
Stack for the sake of easy
access to linked data software.
 the LOD2 software stack is an
integrated distribution of
aligned tools supporting the
life-cycle of Linked Data from
extraction, authoring/creation
over enrichment, interlinking,
fusing to visualization and
maintenance
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LOD2 Stack 3.0
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LOD2 Stack : The overview of tools
 Apache Stanbol
 In the LOD2 Stack, Apache Stanbol can be used for NLP services
which rely on the stack internal knowledge bases, such as named
entity recognition and text classification.
 CubeViz
 CubeViz is a facetted browser for statistical data utilizing the RDF
Data Cube vocabulary which is the state-of-the-art in representing
statistical data in RDF.
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LOD2 Stack : The overview of tools
 Dbpedia Spotlight
 DBpedia Spotlight is a tool for automatically annotating mentions
of DBpedia resources in text, providing a solution for linking
unstructured information sources to the Linked Open Data cloud
through DBpedia.
 D2RQ
 D2RQ is a system for accessing relational databases(RDBMS) as
virtual RDF graphs.
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LOD2 Stack : The overview of tools
 DL-Learner
 The DL-Learner software learns concepts in Description Logics
(DLs) from user-provided examples. (Supervised-learning)
 ORE
 The ORE (Ontology Repair and Enrichment) tool allows for
knowledge engineers to improve an OWL ontology by fixing
inconsistencies and making suggestions for adding further axioms
to it.
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LOD2 Stack : The overview of tools
 Poolparty
 The PoolParty Extractor (PPX) offers an API providing text mining
algorithms based on semantic knowledge models.
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LOD2 Stack : The overview of tools
 SemMap
 SemMap allows to visualize knowledge bases having a spatial
dimension.
 Silk
 The Silk Link Discovery Framework supports data publishers in
accomplishing the second task. Using the declarative Silk - Link
Specification Language (Silk-LSL), developers can specify which
types of RDF links should be discovered between data sources as
well as which conditions data items must fulfill in order to be
interlinked.
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LOD2 Stack : The overview of tools
 Sieve
 Sieve allows Web data to be filtered according to different data
quality assessment policies and provides for fusing Web data
according to different conflict resolution methods.
 LIMES
 LIMES is a link discovery framework for the Web of Data. It
implements time-efficient approaches for large-scale link
discovery based on the characteristics of metric spaces.
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Silk : Link Discovery Framework
 Interlinking and Fusion Stage Component of LOD2 Stack
 Can be used by data providers to generate RDF links between data
sets on the web of data
• Especially, to set explicit RDF links between data items within different
data sources
 “Data publishers can use Silk to set RDF links from their data
sources to other data sources on the Web”
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Silk : Silk – Link Specification Language Example
 Aggregation Example:
 Combines multiple confidence values into a single value (average)
Confidence value is the average of
two compared weight
Numeric differences between parameters
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DL-Learner
 Introduction
 The goal of DL-Learner is to provide a DL/OWL based machine
learning tool to solve supervised learning tasks.
 The DL-Learner software learns concepts in Description Logics
(DLs) from examples.
DL-Learner : Features
 Learning Problems
 Positive and Negative Examples (=previous example)
 Class Learning
• Find out Class Expression for given class
• father ≡ hasChild 𝐬𝐨𝐦𝐞 male 𝐨𝐫 female 𝐚𝐧𝐝 𝐧𝐨𝐭 female
Demo of SDT Plug-in to Protégé
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SWCL - Sample Example
Country
PopulationValue
?
hasPart
Province
positiveInteger
PopulationValue
positiveInteger
𝑥. 𝑝𝑜𝑝𝑢𝑙𝑎𝑡𝑖𝑜𝑛𝑉𝑎𝑙𝑢𝑒 = 𝑦. 𝑝𝑜𝑝𝑢𝑙𝑎𝑡𝑖𝑜𝑛𝑉𝑎𝑙𝑢𝑒, for all 𝑦 ∈ 𝐶𝑜𝑢𝑛𝑡𝑟𝑦
𝑥∈ℎ𝑎𝑠𝑃𝑎𝑟𝑡 − . 𝑦
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𝐶
Constraints Representation in SWCL
 Target Constraint

𝑥∈ℎ𝑎𝑠𝑃𝑎𝑟𝑡 − . 𝑦
𝑥. 𝑝𝑜𝑝𝑢𝑙𝑎𝑡𝑖𝑜𝑛𝑉𝑎𝑙𝑢𝑒 = 𝑦. 𝑝𝑜𝑝𝑢𝑙𝑎𝑡𝑖𝑜𝑛𝑉𝑎𝑙𝑢𝑒, for all 𝑦 ∈ 𝐶𝑜𝑢𝑛𝑡𝑟𝑦
 Corresponding SWCL Code
<swcl:Constraint rdf:ID=”numberOfPopulation">
<swcl:qualifier>
<swcl:Variable rdf:id="y">
<swcl:bindingClass rdf:resource="#Country"/>
</swcl:Variable>
</swcl:qualifier>
<swcl:hasLHS>
<swcl:TermBlock rdf:ID="termBlock_1">
<swcl:sign rdf:resource="&swcl;plus"/>
<swcl:aggregateOperator rdf:resource="&swcl;Sigma"/>
<swcl:parameter>
<swcl:Variable rdf:id="x">
<rdfs:subClassOf>
<owl:Restriction>
<owl:onProperty rdf:resource="#partOf"/>
<owl:hasValue rdf:resource="#y"/>
</owl:Restriction>
</rdfs:subClassOf>
</swcl:Variable>
</swcl:parameter>
<swcl:factor>
<swcl:FactorAtom>
<swcl:bindingClass rdf:resource="#x"/>
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𝐶
Our Direction to the Future
 Directions
 Open, Share your data, whenever and wherever you want
 Semantic, Enhance your data, to make more sense of it
 An example: LinkedGeoData.org
 We need an integrated framework to enhance communication and
information sharing in GeoData.
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Q&A
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