The DBLP Computer Science Bibliography: Evolution, Research Issues,PerspectivesSPIRE 2002Lisbon, Portugal

Michael Ley

Thank you for the invitationMany of you use DBLPThis talk gives some background information about the serviceYou are invited to use the DBLP data to test and evaluate for your algorithms

Michael Ley

About me born March 19591986 diploma in informatics from Aachen University of Technology1993 Ph.D. from University of Triersince 1993 lecturer at U TrierProgramming for 1st/2nd year studentsDB implementation, Digital Libraries

Michael Ley

OutlineHistoryTechnical BackgroundPerspectives & Research Issues

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1. History

The BeginningPerson PagesServiceEary Recognition

ACM SIGMOD AnthologySponorGrowth of DBLPSoftware Labs

Michael Ley

The BeginningEnd of 1993 - simple test of Web technology: Xmosaic, NCSA HTTP serverTables of contents:Journals and proceedingsDataBase systems / Logic Programming

Michael Ley

Basic Architecture

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Person-Publication Network

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Person-Publication NetworkAdding a hyperlink from each person name to a page which enumerates this persons publicationsResult of the complex social network behind researchDB, IR: simply a view, a canned query

Michael Ley

DBLP is a service, not a research projectlimited resourcestrade-off: development of new features & softwarevs. entering & maintaining contents

Michael Ley

No DBMS used until todayprototype implementations (diploma theses): DBLP with SHORE, DB2+better tools to maintain consistencysoftware too large for maintenencetrade-off: disk-space vs. CPU speed

Michael Ley

Early Recognition1997:ACM SIGMOD Service AwardVLDB Endowment Special Recognition AwardHelped to make DBLP a more official project & to get a small inital fund

Michael Ley

ACM SIGMOD AnthologySIGMOD had made some profits with its conferences Idea by Rick Snodgrass:use the money to scan in historical DB publicationsCombine these full texts and an improved version of DBLP to a digital libary

Michael Ley

Anthology: ContentsJournals, Newsletters:TODSTKDEVLDB JournalDistr. & Parallel DBData Engineering

SIGMOD RecordSIGKDD Expl.SIGIR ForumData Base

Michael Ley

Proceedings:ACM DLACM GISADBISCIKMCOOPISDASFAADBPLDOLAPEDBTERHypertextICDTKRDBMFDBSNPIVPDISPODSPOSSIGIRSIGMODSIGFIDETSSDSSDBMVLDBXP+several Workshops

Michael Ley

Books:Abiteboul/Hull/Vianu: Foundations of DBsBernstein/Hadzilacos/Goodman: Concurrency Control and Recovery in Database SystemsMaier: Theory of Relational DatabasesGray: The Benchmark HandbookStonebraker: The INGRES PapersWiederhold: Database Design (2nd Ed.)Snodgrass: The TSQL2 Temporal Query L.

Michael Ley

21 CDROMs / 2 DVDs >150000 pages full text

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Anthology: Citation LinksReferences:[1] [2] B: xxx.[3] References:[1] Referenced by: A: yyy.

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Sponsor Found / Expansionhelp by MS Research & Jim Gray made it possible to expand DBLP to cover most areas of computer sciencestudents were hired to enter data

Michael Ley

Growth of DBLP

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Teaching Java At U Trier we teach Java as the first programming languageAssignments: DBLP XML data are usedgraph algorithmsuser interfacessimple search engines

Michael Ley

2. Technical Background

Initial DesignPerson PagesMirrorsSimple Search

XML-RecordsBHT-FilesMG: advanced searchAnthology search

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Initial DesignEntry pagesCollection of HTML tables of contentsTOCs were parsed to generate Person Pages (customized xmosaic parser)Person Index

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TOC Parser / Generation of Person PagesParserTOC_OUTmkauthorsTOCsPersonPages

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MirrorsUniversity of Trier had a slow internet connectionsDBLP should have a high availabilityTechnique:transfer all TOCs + entry pages + TOC_OUT in a tar.gz filerun mkauthors on the mirror

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TOC_OUTtitleCGI

Bibliographic Recordscitation linking, reviews, annotated bibliographies, assign an unique ID to each publicationmake it accessible by this IDstore the information in classical bibliograhic records

Michael Ley

Bibliographic Records You may download them from http://dblp.uni-trier.de/xml/ (uncompressed ~120MByte)Simple DTD Idea: BibTeX++ in XML syntaxExamples

Michael Ley

Andreas OberweisWolffried StuckyDie Behandlung von Ausnahmen in Software-Systemen: Eine Literaturbersicht.492-502199133Wirtschaftsinformatik6db/journals/wi/wi33.html#OberweisS91

Michael Ley

Andreas OberweisOliver PaulzenHagen J. SexauerEin wissensbasiertes Vorgehensmodell zur Gestaltung von CRM-Systemen.429-4362001GI Jahrestagung (1)db/conf/gi/gi2001-1.html#OberweisPS01

Michael Ley

Peter JaeschkeAndreas OberweisWolffried StuckyExtending ER Model Clustering by Relationship Clustering.451-4621993ERdb/conf/er/er93.html#JaeschkeOS93conf/er/93er93/ER93-P447.pdfdb/conf/er/JaeschkeOS93.html

Michael Ley

conf/er/CarlsonJA89journals/tods/Chen76journals/cj/FeldmanM86......conf/er/RauhS92...conf/er/ScheuermannSW79journals/csur/TeoreyYF86journals/cacm/TeoreyWBK89

Michael Ley

Ramez ElmasriVram KouramajianBernhard ThalheimEntity-Relationship Approach - ER'93, 12th International Conference on the Entity-Relationship Approach, Arlington, Texas, USA, December 15-17, 1993, ProceedingsERLecture Notes in Computer Science823Springer19943-540-58217-7db/conf/er/er93.html

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Publication Types

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XML Parser / Generation of Person PagesParserTOC_OUTmkauthorsXML-RecordsPersonPages

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Tables of Contents,

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Bibliography HyperText (BHT)include mechanism ()several addtional tags: , , , HTML

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25. SIGIR 2002: Tampere, Finland 25. SIGIR 2002: Tampere,Finland

Web Information Retrieval

Information Retrieval Theory

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Advanced Search: MGManaging Gigabytes Software by Witten, Moffat, BellDBLP XML Records MG DocumentsFilter: matching terms in the required field

Michael Ley

DBLP ArchitectureEntry PagesPerson PagesStreams: Conference Series,JournalsTables of Content (TOC)PersonSearchAdvancedSearchgeneratedanswers

Michael Ley

Entering DataStudentsWWW, E-MailwrappermkhtmlBibTeXBibTeXBHT

Michael Ley

Anthology: Offline SearchSimple search engine for all standard platforms Java Applet (Java 1.0)Only author searchApplet reads simple tree data structure from files:

Michael Ley

curran,john Hcutting,dczarnecki,hdabbaghcdagmar brdaigrdale rodambrdan cartdan smdang,zdaniel d. fudaniel j. burdaniel menddaniel sadaniela merdannenberg,cdaradroot:separatorsMann,Robert I.Mann,Sally Fahrenholz-Mann,SamuelMann,StefanMann,StephenMann-Ho LeeMann-May YauManna,I.Manna,M. LaManna,Serena LaManna,ZoharMannai,Dhamir N.Mannarino,Gabriela SusanaMannava,Phanindra K.Manne,FredrikManne,SrilathaManneback,Pierreleaves: names(permutationsof name parts)

Michael Ley

Michael Ley

Anthology: Full Text SearchAcrobat catalog: index constructioncapture: OCR for scanned textsmanual entry of title fields was necessaryinsufficient software support by AdobeAcrobat Reader with searchnot available for Linux

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3. Perspectives & Research Issues

Funding & collaborationsPerson Names

DBLP BrowserVisualizationClassification / Clustering

Michael Ley

Informatics PortalDBLP will be a central part of a larger Informatics PortalOther parts:CompuScience (FIZ Karlsruhe)Collection of CS Bibliographies (Achilles/Vollmer, Karlsruhe)LeaBib (Mayr, Munich)

Michael Ley

Informatics Portal (2)Funded by the German Federal Ministry of Education and Research, 3 yearsIn Cooperation with the Gesellschaft fr Informatik (German Computer Society)2 open positions at Trier: service+research

Michael Ley

Additional Contents complete coverage of LNCSmore ACM & IEEE publicationscooperation with IFIP, Usenix, cooperation with the libraries at Dagstuhl & Max-Planck-Institut fr Informatik (Saarbrcken)several German series (LNI,IA,IFB)

Michael Ley

Number of records by publication year(24 August 2002)

Michael Ley

Challenge: How to manage the exponential growth of (computer)science publications ?maintenance problemlost in publication space

Michael Ley

Person Nameswidely accepted method to identify personsnames may not be uniquea person may change her/his name (marriage, emigration to other cultural environment)variations of person names

Michael Ley

abbreviations: Jeffrey D. Ullman, J. D. Ullman, J. Ullman, Jeff Ullman, nicknames: Michael / Mike, William / Bill, Joseph / Joepermutations: Liu Bin / Bin Liudifferent transcriptions: Andrei / Andrej / Andreyaccents: Stephane / Stphaneumlauts: Muller / Mller / Mueller

Michael Ley

ligatures: Wei / Weiss, strm / Aastromcase: Al-AAli / Al-Aalihyphens: Hans-Peter / Hans Petercomposition: MaoLin / Mao Lin, Kenichi / Ken-ichi / Kenichipostfixes: Karel Culik II, Jr. / Sr.typos

Michael Ley

Person Names: Problemsthere should be a 1:1 mapping between persons and person pageshow to search persons best ?how to normalize different spellings ?name normalization costs morethan 60% of our time

Michael Ley

Person Name Normalizationfor each new entry we try to locate the authors/editors in the existing collectionif spellings differ, but we are confident that they are variations of the same persons name make them equalwrite out most parts of the namepersons perferred spelling ?

Michael Ley

for persons with many publications the name spelling usually converges to a stable & correct statefor persons with a few known publications it is more likely that there are duplicate person pages, incorrect or incomplete spellings

Michael Ley

Heuristics in the decision process coauthor relationship gives strong indications for the identity of personsstreams (journals/conference series): condensation points for communities, weaker indicationsame keywords in titlestime frame ?a lot of background knowledge

Michael Ley

Wanted: Tool to make DBLP maintenance more efficientspecialized weight functions for the name normalization problemquery: new entry = list of names, title, publication stream, year, DBLP browser: framework for experiments

Michael Ley

DBLP Browser: Rolesmaintenance toolbibliographic tool for users of DBLPcomposition of reference listsexport in popular formats like BibTeXplatform for experiments in visualization (SemIPort project )

Michael Ley

DBLP Browsermain memory IR systemcompressed representation of the bibliographic recordsconvenient graphical user interfaceJava / Swingfirst prototype implemented

Michael Ley

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Danny De SchreyeMaurice BruynoogheKristof VerschaetseOn the Existence of Nonterminating Queries for a Restricted Class of PROLOG-Clauses.237-248198941Artificial Intelligence2db/journals/ai/ai41.html#SchreyeBV89

Michael Ley

Representation of -Fields:construct canonical Huffman codes on word level [MG-Book]degree of tree-nodes: 213 (0x2a-0xff)lexicon: 3-in-4 front codingPublications are sorted by journal/booktitle, year

Michael Ley

7Comprehending32sibility5-ons0sion2Compress21ibility3+n3onless6Compressions3,ve2.lets2or5Compressors/-ise2+d2s4Comprising/5omisability3,ed4s6Compromising0+r..sing.ter2Compters0,ur/-ing/on2Comptuer.4uatational1-ion4al5Compuations20tional//iting/log4Compulsory/,nd0.ting/s0Comput03abilities2-les3y7Computacional1-ion4,al1ting7Computationai6.lism5,el4onsLexicon oftitle words0=*, 1=+, 2=',', 3='-',4='.', 5='/', 6='0', 7='1',

Michael Ley

Lexicon: title words

Danny De SchreyeMaurice BruynoogheKristof Verschaetsec1c2c3 ...237-248

Michael Ley

Representation of - and -Fields:construct list of all personssort them by number of publicationsadd inverted lists (publication numbers) to all persons

Peter Smith 17 36 1003 7790 8800Johanna Mayer 36 2077 9002

Michael Ley

Representation of inverted indexesuse d-gaps [MG-book]variable-byte coding (base 111 numbers, 7bit value + last byte flag) [Scholer et al., SIGIR 2002]

Michael Ley

Alberto H. F. Laender)s"b~5"\"@&$"8?\"$"i$-"cUL"?"

Lexicon: title words

a1 a2a3 c1c2c3 ...237-248Artificial Intelligence

Person table

Michael Ley

Representation of - and -Fields:construct lists of all journals and booktitlesadd position of first publication with this journal/booktitle and countArtificial Intelligence 5000 603TODS 7890 400

Michael Ley

33110509CACM)#^PTCS)7IKIEEE Transactions on Computers),[IInformation Processing Letters)/KHTSE)896IEEE Computer)+5JACM)0|5The Computer Journal)8U3SIAM J. Comput.)5@3Software - Practice and Experience)6z2Artificial Intelligence)"0Information and Control)//JCSS)12/IEEE Transactions on Pattern Analysis and Machine Intelligence),.

Michael Ley

Lexicon: title words

a1 a2a3 c1c2c3 ...237-248 j 2db/journals/ai/ai41.html#SchreyeBV89

Person tableJournal tableBooktitle table

Michael Ley

Representations of Paths: key, , construct paths dictionary: bottom-up tree of path elemensconfvldbspiresigirGray88Ullman91

Michael Ley

Lexicon: title wordsPerson tableJournal tableBooktitle tablepaths dictionaryseries tablepublishers tableAvSchreyeBV89)Tff:ff*fLfffNf3;ffHl3Km)g#uvYpb#""+Ap1SchreyeBV89Tl1l2)gn1n2up2Yypjvnb3a1a2a3

Michael Ley

DBLP Browser: Compression

Michael Ley

DBLP (Browser): next stepsearchvisualizationBHT files, but standard cases should not require BHT files: extentsion of the BibTeX data model

Michael Ley

Extension of the BibTeX data modelinproceedingsproceedingsconferenceperiodicalpvolumearticlestreamvolumepapercrossrefcrossrefcrossrefcrossrefcitecitecitecite

Michael Ley

Conference on Very Large DatabasesVLDBdb/conf/vldb/index.html

conf/vldb/2002 conf/vldb/2001

Michael Ley

User Interfaces for Bibliographic Collectionsconventional wisdom: provide a good IR systemDBLP: browsing oriented interface + very simple search tools

Why is DBLP nervertheless used?

Michael Ley

there was little comprehensive searching by faculty researchers because they worked within specialized forums where they could more efficiently find the materials they needed. This precluded comprehensive searching to identify an exhaustive set of materials in a wider variety of forums. [] They also used browsing to examine electronic announcements of conferences, and tables of contents of journals [Lisa Covi, PhD thesis 1996]

Michael Ley

Problems of the many search-oriented Web-PortalsHow to query ?Description / characterization of the collection unknown

Michael Ley

views visualizations diagrams global characterizations of the collection (coarse navigation)stream level diagramsperson page visualizations

Michael Ley

global characterizations

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number of publicationspersons

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Diagramm3

Diagramm3

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120250

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Tabelle1

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48570

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1691Avi Wigderson

1701Oscar H. Ibarra

171

1721Jeffrey Scott Vitter

1732Joseph Halpern / Abraham Silberschatz

174

1752Sushil Jajodia / Moti Yung

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1871Michael Stonebraker

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1911Robert Endre Tarjan

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1971Oded Goldreich

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2061Micha Sharir

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2181Kang G. Shin

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2201Moshe Y. Vardi

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2271Jeffrey D. Ullman

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2381Hector Garcia-Molina

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481

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202

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169

156

138

151

138

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94

116

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95

87

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77

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ClassificationACM CR Systemclassifications only avalable for small subset of computer science literatureoften criticized as too inflexible / too coarseintellectual classification (on the paper level) is too expensive

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Clustering on stream levelrelated conferences or journals:in which other streams did the authors of this stream publish most frequently ?todo: what is most frequently?what is the neighborbood of a stream ?

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CRYPTOEUROCRYPTSTOCFOCSSIAM J. Co.ASIACRYPTTCSJCSSIPLACISPPubl.Key Cry.JoC

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Thank you for your attentionPorta Nigra the most famous landmark of Trier

Michael Ley