High Energy Physics Libraries Webzine
HEP Libraries Webzine
Issue 5 / Novembre 2001
Antonella De Robbio (*), Dario Maguolo (*), Alberto Marini (**)
In the present work we discuss opportunities, problems, tools and techniques
encountered when interconnecting discipline-specific subject classifications,
primarily organized as search devices in bibliographic databases, with general
classifications originally devised for book shelving in public libraries.
We first state the fundamental distinction between topical (or subject) classifications and object classifications. Then we trace the structural limitations that have constrained subject classifications since their library origins, and the devices that were used to overcome the gap with genuine knowledge representation.
After recalling some general notions on structure, dynamics and interferences of subject classifications and of the objects they refer to, we sketch a synthetic overview on discipline-specific classifications in Mathematics, Computing and Physics, on one hand, and on general classifications on the other.
In this setting we present The Scientific Classifications Page, which collects groups of Web pages produced by a pool of software tools for developing hypertextual presentations of single or paired subject classifications from sequential source files, as well as facilities for gathering information from KWIC lists of classification descriptions.
Further we propose a concept-oriented methodology for interconnecting subject classifications, with the concrete support of a relational analysis of the whole Mathematics Subject Classification through its evolution since 1959.
Finally, we recall a very basic method for interconnection provided by coreference in bibliographic records among index elements from different systems, and point out the advantages of establishing the conditions of a more widespread application of such a method.
A part of these contents was presented under the title Mathematics Subject Classification and related Classifications in the Digital World at the Eighth International Conference Crimea 2001, "Libraries and Associations in the Transient World: New Technologies and New Forms of Cooperation", Sudak, Ukraine, June 9-17, 2001, in a special session on electronic libraries, electronic publishing and electronic information in science chaired by Bernd Wegner, Editor-in-Chief of Zentralblatt MATH.
Connecting Classifications in the Digital World
Users in different settings, with different demands and expectations want
to fulfil their information needs wherever information is available, cutting
costs and time as much or more than possible, regardless of the heterogeneity
of sources: from quite specialized databases or dedicated portals to general
online library catalogues or Web search engines, from reference (metadata)
databases to full-text or hypermedial digital libraries, from e-journal
aggregators to preprint servers and authors' self-archives (commonly called
The organization, the functionalities and the interaction modes exploited by networked digital libraries may be completely different from those generally met with in traditional paper-based libraries. Moreover, for e-print systems, the development of technical mechanisms and organizational structures to support their interoperability, which is promoted by the Open Archives Initiative (OAI) , is making them evolve into genuine building blocks of a transformed scholarly communication model, radically different from the traditional one, which is dominated by the heavy mediation business of scholarly publishing companies.
On the other hand, users do not want to adjust to the particular way of
storing, indexing and presenting information of every source they face: this
should be automatically worked out by the system. But such a task is not
As for subject indexing, different classifications, thesauri or otherwise structured terminologies, or even ontologies, while covering the same area, can keep presenting strong linguistic (which can not be worked out by mere translation), structural and semantic disagreements, in spite of any effort for harmonization. Dramatic disagreements are evidenced in passing from the specialized world of discipline-oriented classifications to general classifications widely used in public, school or even general academic libraries, such as Dewey Decimal Classification, Universal Decimal Classification or Library of Congress Classification.
Misinterpretations occur when the same words are used in different contexts
or for different purposes. Moreover, even in using one and the same
classification, differences and inconsistencies are normal practice, either
among different applications or inside the same application. One could expect
that good interconnections among classifications are at the basis of good
retrieval across classifications, but this seems not to be the common
While a number of approaches to the issues of connecting classifications or thesauri exploit statistical methods or neural network techniques, a different trend is oriented towards the analysis, modeling and support of conceptual organization by humans. The former can be very helpful, even in view of the latter; a well-defined integration seems to be the recipe for the near future [see D01].
Actually, it's still worth while, and not only for educational purposes, to work out well-defined connections between classifications or the like, such that the objects to which each of them refers are identified unambiguously by means of a suitable representation language. With the knowledge representation languages currently being designed and implemented in computer applications, this task is becoming feasible.
Subject Classifications and Object Classifications
A (topical or object) classification can be given an appropriate semantics
in terms of some notion of space, possibly less constrained and more complex
than usual material ones, even if it is not involved in physical space
arrangement, but acts as a pure information device, e.g. in computer-managed
The space of topical classifications is the form of a container, a grossly operative space for concept packaging and package linking; it is quite different from the space of objects as they are actually intended by classification users, a space that can be more or less definitely taken off from the classification like a conceptual space of true effective meanings.
Objects, be they material or not, exist in temporal and relational
arrangements: they can begin and end, split and merge, exchange parts with
other objects, increase or decrease their extent, scope or complexity, change
characteristics and relations with other objects, and can be perceived and
managed differently in time.
Classifications evolve too, as objects' clothes (topical classifications) or description structures (object classifications), through different versions that come in use subsequently, according to different perceptions, or awareness, of objects and their environments, or to changes in tools and techniques for representing them, and for managing such representations. A single version of a classification offers a snapshot of a system of objects; a sound knowledge of objects, in their intrinsically changing nature and in their changing contexts, can be acquired by looking through classifications which refer to them, provided that a comprehensive follow-up of versions is observed.
To Tree or Not To Tree: the Question Between
Partitioning Space and Representing Knowledge
At the crossroad of Artificial Intelligence, Computational Linguistics and
Database Theory, such complex structures can be represented with effectiveness
in the frame of reference of Formal Ontology , by means
of formalisms like Conceptual Graphs (CG) , Description
Logics (DL) , and the Unified Modeling Language (UML)
[BJR98], which comes from the field of software
engineering and is proposed as an approach for modeling ontologies and
encoding the knowledge content of Web pages [C01].
Metadata formats for document representation are being defined progressively in this way; the draft for the Academic Metadata Format [KW01], which is being defined in the scope of the Open Archives Initiative, is a clear example of such a trend .
In the case of subject classifications, structured representations (which
were conceivable even in times when formal languages for expressing them were
lacking) have yet to be cut down to get compliance with the tree-like forms in
which subject classifications constrain their operability. Although this
reduction involves unavoidably serious information losses, subject
classifications have been provided with more or less effective devices to
remedy for this gap.
From the pioneering work of Ranganathan since 1933 with Colon Classification, through the elaborations of the British Classification Research Group in the '50s and '60s, the addition of Auxiliary Tables to the Dewey Decimal Classification since its 18th edition, published in 1971 [see CCMS96], the development of the Preserved Context Indexing System (PRECIS) in the '70s, and the publication in 1986 of the standard ISO 2788 (BS 5723) Guidelines for the establishment and development of monolingual thesauri, a compositional approach to subject analysis, named facet analysis, has been progressively established [F96]. Within facet analysis, complex concepts are decomposed into combinations, specified by means of role indicators, of atomic elements, which belong to homogeneous, mutually exclusive classes, the facets [AGB97].
Turning back to subject classifications, an organization of the
classification space (named pre-coordination) which permits complex
objects to be recovered via suitably compound addresses, and a more or less
rich and organized apparatus of cross-references between places, are useful
means especially if objects are to be located in one place only.
If a subject classification is used in settings that allow the simultaneous employment of different classification codes for the same object, mechanisms and directions for post-coordination are provided in order to partially recover complex meaning by listing addresses together in suitable ways, either in databases that offer information or in queries that ask for it.
By definition, subject classifications are plainly rougher, or less fine-grained than thesauri and modern ontologies; anyway, standard relationships that are used to connect classification codes are rather blurred and their intrinsic significance is very loose. But this is the case also for thesauri and even for many ontologies. In order to recover capabilities for sound conceptual representation of intended entities and relationships, and so for effective accomplishment of retrieval tasks, a careful disambiguation for expressed relationships is appealed to for both thesauri and ontologies , by introducing well-defined and ontologically grounded specializations. As for subject classifications, we shall instead advance a topological argument to try to get an account for such relationships.
Descriptions and Addresses:
Visiting a Subject Classification Space
Subject classification descriptions, be they textual or otherwise
performed, are a means to orientate the user in the classification space. They
refer to objects through the mediation of places that gather them, or channels
that convey them, in order to meet some external specifications or constraints
(human readability, manageability for use). So one description may refer to a
collection of objects that are intended distinctly by the user, but are
collected according to the classification organization. On the other hand, one
object or place may be represented in different forms, still observing the
linguistic or semiotic conventions of the classification.
Thesauri and lists of subject headings, on the contrary, need to maintain a tight correspondence between objects and descriptions, at the price of bothering about preferred and non-preferred forms: but this amounts to constraining the variety of natural language to pass through the cog-wheel of machine identifiers. The addition of more or less free-text scope notes is a further signal of this blurring.
It is the role of addresses to guide the travel machinery: for this work
there is no need to know why the traveller wants to reach a certain place, and
to find what. So in subject classifications addresses (commonly named
classification codes or numbers) are fundamental in their very
form for material document shelving in material libraries, and lists of
addresses are major means for subject indexing in bibliographic databases and
online library catalogues; addresses encode and display the space structure,
but they act as mere linking elements, without any real semantic
The real carriers of semantic content are descriptions, and the classification organizes them inside a structure that exists independently from the actual forms of the addresses, i.e. from the forms that are fixed for representing the classification space structure in view of external reference and linking.
Moreover, while both descriptions and addresses can change, in time or
across different linguistic, semiotic or encoding conventions, it is not
necessary that they change in dependence on one another, or on the changes,
transformations, births and deaths among the objects, the spaces and the ways
objects and spaces are organized and perceived. Addresses may change while
descriptions remain the same, or space structure, at least locally, is
preserved; descriptions may change while objects remain the same; objects may
change while addresses remain the same, and so on.
Different classifications that cover overlapping areas can exercise in time influence on one another, especially on structure and descriptions, in order to get similar or compatible views of the same objects, even if they are seen from different viewpoints or on different scales, and different groupings can be kept within each classification.
Subject Classifications in Mathematics, Computing, Physics
Mathematics Subject Classification (MSC)
MSC is compiled and updated by the editorial offices of the world's most important bibliographical directories for mathematical research: MathSci and Zentralblatt MATH.
The classification covers all branches of pure and applied mathematics, including probability and statistics, numerical analysis and computing, mathematical physics and economics, systems theory and control, information and communication theory.
The MathSci Database
MathSci is produced by the American Mathematical Society (AMS).
The paper version consists of the journals Mathematical Reviews (MR), published since 1940, and Current Mathematical Publications (CMP).
MSC, compiled since 1959 (by AMS alone until the early '70s), in the first years of its existence was very unstable. So, for the part which appeared in print from 1940 to 1972, the MathSci database received new classification data, which are stable for relatively long periods (1940-1958, 1959-1972) and therefore more suitable for database searching than the frequently varying ones of the print version. Starting with 1973 the database is indexed with the same classification codes as the print version. 
The Zentralblatt MATH Database
Zentralblatt MATH is edited by the European Mathematical Society (EMS), the Fachinformationszentrum (FIZ) Karlsruhe and the Heidelberg Akademie der Wissenschaften (Germany); it is established in cooperation with Cellule de Coordination Documentaire Nationale pour les Mathimatiques (Math Doc Cell, France). Several European Editorial Units cooperate with the Editorial Office in Berlin.
The paper version consists of the journal Zentralblatt MATH (with this title since 1999), founded as Zentralblatt f|r Mathematik und ihre Grenzgebiete in 1931, formerly issued by Deutschen Akademie der Wissenschaften zu Berlin; published since 1931 by Springer.
The database is indexed with the 1991 and 2000 MSC versions; some superseded classification codes from preceding versions are also present. 
The Evolving Structure of MSC
After 1973 major MSC revisions came into use in 1980, 1985, 1986, 1991, 2000.
From 1959 to 1985 the MathSci version of MSC counts 60 major sections; 61 from 1986 to 1999 and 63 since 2000.
Until 1972 the classification was issued in two levels; an intermediate level became available in 1973, and is progressively being exploited, as MSC increases in detail and so grows in size.
Started with 1436 numbers in 1959, MSC counted 4895 numbers in 1999 and 5590 since 2000.
A consistent and ever growing apparatus of cross references helps in understanding connections between different branches of mathematics.
The EULER Project
Mathematics Subject Classification is one of the classification systems provided for by the Dublin Core (DC) metadata format, and is used inside DC metadata for the search engine developed in the European Union project European Libraries and Electronic Resources in Mathematical Science (EULER) .
The main objective of EULER was the realization of a "one-stop shop" for research on mathematics information resources such as books, pre-prints, Web pages, abstracts, collections of articles and reviews, periodicals, technical reports and theses.
The result is a Web meta-interface for parallel simultaneous queries to a heterogeneous collection of databases.
Referativnyj Zhurnal: Matematika. Classification
It was prepared as a piece of the Universal Decimal Classification (UDC) for Referativnyj zhurnal: Matematika. An English translation is provided by the AMS site .
Zentralblatt f|r Didaktik der Mathematik Classification
Scheme (ZDM) 
This scheme is used for the bibliographic database on mathematics education and related fields MATHDI, active since 1976, which can be accessed through the sites of the European Mathematical Information Service (EMIS).
The paper version of the database is Zentralblatt fur Didaktik der Mathematik.
ACM Computing Classification System
This classification is issued by the Association for Computing Machinery (ACM) in the USA, for the directories Computing Reviews (CR) and Guide to Computing Literature (GCL).
Moreover, it is adopted by the bibliographic database CompuScience, produced by Fachinformationszentrum (FIZ) Karlsruhe, Department of Mathematics & Computer Science Berlin, which contains references from CR since 1976, from GCL since 1977 and from Section 68 Computer Science of MSC in ZM/MA.
ACM's first classification system for the computing field was published in 1964. Then, in 1982, the ACM published an entirely new system. New versions based on the 1982 system followed, in 1983, 1987, 1991, and 1998 .
Physics and Astronomy Classification
PACS is prepared by the American Institute of Physics (AIP) in collaboration with certain other members of the International Council on Scientific and Technical Information (ICSTI) having an interest in physics and astronomy classification. The most recent internationally agreed scheme was published by ICSTI in 1991.
Revised editions of PACS are published biennially, or as necessary, by AIP.
PACS contains 10 broad categories subdivided into 66 major topics .
INSPEC Classification 
INSPEC is an English-language bibliographic information service providing access to the world's scientific and technical literature in physics, electrical engineering, electronics, communications, control engineering, computers and computing, and information technology.
INSPEC was formed in 1967, based on the Science Abstracts service, which has been provided by the Institution of Electrical Engineers (UK) since 1898. Still today Physics Abstracts, Electrical & Electronics Abstracts and Computer & Control Abstracts together form the Science Abstracts series of journals, which is the paper version of the INSPEC database.
INSPEC Classification is divided into four major sections:
General Library Subject Classifications
Dewey Decimal Classification 
The Dewey Decimal Classification (DDC) system was conceived by Melvil Dewey in 1873 and first published in 1876. The latest (21st) edition was released in 1996, so there is an average 6 year period between one edition and the next.
The Dewey Decimal Classification is published in two editions, full and abridged.
The Classification is kept up-to-date electronically through electronic versions: Dewey for Windows, a CD-ROM product that is updated annually; and WebDewey in CORC, a Web-based product that is updated quarterly.
The DDC is published by Forest Press, a division of OCLC Online Computer Library Center, Inc.
DDC is widely used all over the world, not only for book shelving in
libraries, especially in public, school and general academic ones, but also
for subject indexing and browsing in general online document retrieval tools,
such as bibliographic databases (including the national bibliographies of
sixty countries), online library catalogues (including WorldCat, the OCLC
Online Union Catalog), digital libraries, Web search engines.
The DDC has been translated into over thirty languages.
The classification is developed and maintained in the US national
bibliographic agency, the Library of Congress.
The Dewey editorial office is located in the Decimal Classification Division of the Library of Congress, where annually the classification specialists assign over 110,000 DDC numbers to records for works cataloged by the Library. Having the editorial office within the Decimal Classification Division enables the editors to detect trends in the literature that must be incorporated into the Classification. The editors prepare proposed schedule revisions and expansions, and forward the proposals to the Decimal Classification Editorial Policy Committee (EPC) for review and recommended action.
The print version of Edition 21 is composed of nine major parts in four volumes as follows:
Volumes 2 and 3:
Universal Decimal Classification
UDC was created towards the end of the nineteenth century by Paul Otlet and Henri LaFontaine as an adaptation of DDC in view of the preparation of a universal bibliography.
Until recently responsibility for the scheme belonged to the FID (Federation Internationale de Documentation); this responsibility was passed to a consortium of publishers (the UDC Consortium) in 1992.
The scheme consists of 60,000 classes (divisions and sub-divisions) as well as a number of auxiliary tables.
Library of Congress Classification
In 1899 the Librarian of Congress Dr. Herbert Putnam and his Chief Cataloguer Charles Martel decided to start a new classification system for the collections of the Library of Congress (established 1800). Basic features were taken from Charles Ammi Cutter's Expansive Classification.
LCC is an enumerative system built on 21 major classes, each class being given an arbitrary capital letter between A-Z, with 5 exceptions: I, O, W, X, Y.
After this was decided, Putnam delegated the further development of different parts of the system to subject specialists, cataloguers and classifiers.
Initially and intentionally the system was, and has remained, decentralized and the different classes and subclasses were published for the first time between 1899-1940.
This has led to the fact that schedules often differ very much in number and the kinds of revisions accomplished.
Interconnecting Classification Schemes
Within Working Package 12: Cross concordances of classifications and thesauri, programs for interconnecting general classifications such as DDC and discipline-specific ones (MSC, PACS, and the classification for social sciences) are being developed in Java on a relational database system with an abstract intermediate level to allow a transit to different producers of database software.
Displaying Classification Schemes: The Scientific Classifications Page
Various tools for exploring subject classifications have been realized in
this way and are collected in The Scientific Classifications
Besides hypertextual presentations of subject classifications, the page collects some H-volumes presenting KWIC (Key-Word-In-Context) lists extracted from the descriptions of one or more combined classifications. Descriptions are circularly permuted on significant words, i.e. words out of a stop-word list; the very long list of resulting strings is displayed on the right, subdivided into smaller manageable lists, which can be accessed through an index appearing in the left frame. This redundant but properly paginated presentation allows the rapid exploration of lexical similarities among descriptions to obtain suggestions about possible affinities of contents.
The Scientific Classifications Page page includes:
The Mathematics Classification
which collects six hypertextual frame presentations of the latest version of Mathematics Subject Classification, MSC2000.
From a sequential ASCII file containing the whole MSC2000, two H-volumes were obtained, respectively
The same process being worked out on a file containing an Italian translation of MSC2000, we obtained the simple frame
while instead of the double-view one, we processed the two files in combination with the first file, to obtain the simple frame
From the combination of the first ASCII file with others, containing collections of specific data, we obtained other H-volumes:
Mathematics Subject Classification MSC and Dewey
Decimal Classification DDC
We advanced on this line by throwing off connections between classification numbers from the DDC 21 and MSC2000 schemes; a draft page in double view presentation was then produced:
In view of the revision of the 510 section of DDC, Mathematics, we are
updating such a draft along the proposal presented by Giles Martin, Assistant
Editor of the Dewey Decimal Classification .
Meanwhile, we have put together the descriptions of:
- the proposed revision of the 510 DDC section
- the sections E - N of the ZDM classification, encoded as 97E - 97N in the MSC style
to produce the KWIC list H-volume
KWIC (KeyWords In Context) lists for Scientific Subject
The following H-volumes have been produced:
Such preliminary lexical support will be worked out for investigating the
connections among other groups of classification schemes.
Furthermore, some improvements obtainable by discrimination of homonyms, synonyms and secondary terms will be investigated.
Buses in the Classification Space-Time
So the first step in the process of getting objects out of the
classification space is to recognize the buses that carry objects in
time, through a course of succeeding versions of the classification, moving
across the addresses that mark the (possibly changing) paths and places in the
classification space. Each bus during its trip passes through one or more
places; the addresses of such places, with the indication of the period of
passage, set up the schedule for that bus.
Consistent sequences of descriptions have to be identified; such sequences set up the description of buses in the classification space-time. A good taste of the subject matter is needed at this stage; the step can be worked out also with the help of conversion tables, which are generally provided by the classification editorial agencies, especially in case of deep or extensive changes in the classification.
Even if any synchronic slice of the classification space-time is tree-like,
the whole structure may not be tree-like, as nodes or subtrees can migrate
from one branch to another.
Besides the main hierarchical structure, cross-references and explicitly stated pre-coordination and post-coordination mechanisms, taken dynamically as well, give substantial contributions to the definition of the classification space-time.
The Space-Time of Mathematics Subject Classification
The database consists of 25 tables, which can be conceptually arranged in
two layers, each of 11 tables, and 3 tables that account for relationships
between corresponding entities represented in the two layers. Every table
provides data for the beginning and end years of the period of existence of
the object or validity of the relation represented in each record.
The First Layer: Classification Places
The simple entities are:
The compound entities and relationships are:
The Second Layer: Classification Buses
The simple entities are:
The compound entities and relationships are:
The Cross-Layer Relationships
Envelopes and Objects
Getting Objects out of their Envelopes
The further step of the object identification process is the extraction and the refinement of conceptual elements from the descriptions, by means of text analysis techniques on the basis of subject matter knowledge.
Conceptual elements coming from different envelopes can be unified if their contents turn out to be the same; anyway, each conceptual element maintains a relationship with each envelope it comes from.
The Interplay of External and Internal Relational Reasoning
At this point, topological reasoning plays a very significant role: we can accommodate envelopes as formal neighborhoods and conceptual elements as concrete points inside the basic pair that is envisaged in the Basic Picture perspective on Constructive, or Formal, Topology ; the forcing relation accounts for the "comes from" links.
Following a methodology that interleaves topologically minded relational examinations on the space of conceptual elements [V] and relational analyses to be performed by means of a suitable representation language, objects can be identified and described in formats suited for applications.
Object Descriptions in the Metadata Machine
The set of structured descriptions so obtained is the leading pole of the connections: the correct reference links can be established between such descriptions and items in the classifications. Starting from one classification, users can choose for the structured description(s) that correctly represent the intended meaning, and hence pass to the corresponding items in another classification. Moreover, such descriptions should be encoded in the metadata that are managed by search engines. Frequently such standard format metadata sets are the result of conversions from heterogeneous databases, and serve as indexes for queries in the original databases.
Conclusions: the Metadata Machinery and Beyond
While backing such developments, our realizations in subject classification
display are intended to demonstrate possibilities for library OPACs to
integrate their functionalities with discipline-specific environments for
document search and retrieval.
Moreover, our approach could be exploited in the development of gateways and portals pointing to e-print servers. By means of our KWIC list displays for descriptions of single or combined classifications, words or phrases used to describe places in different classification spaces could be turned into addresses of communicating sites in different environments. Through the metadata that match the identified codes in the discipline-specific classifications, an OAI compatible service provider could transform these abstract addresses into actual full-text documents available from discipline-specific servers.
In the near future, the keywords that will index a cooperative effort on scientific classifications will be: OPAC, OAI compatible e-print server, metadata.
|||See the Website at http://www.openarchives.org|
|||see the Website of the Ontology group at LADSEB-CNR
(Padova, Italy), at|
for Formal Ontology in information systems, see [FOIS98];
a more librarianship-oriented perspective in [S00]
for an application of a variant of CG, see [GMV99]
see The DL Website at http://www.ida.liu.se/labs/iislab/people/patla/DL/index.html
|||Further information metadata, in relation with thesauri, can be found in [H01]|
|||For thesauri see [D01, TAJ01].|
For ontologies an evolving line of is thought displayed in [G98, G99, GW00, GW01]
|||The 1995 and 2000 versions are available in hypertextual
|||Math Doc Cell issues a multilingual (French, English,
Italian) Web presentation of the 2000 MSC version, available at|
The English data has been taken from the AMS site
the Italian ones from the the site we set up at
|||See the EULER site: http://www.emis.de/projects/EULER/|
|||A Web presentation of the ZDM classification is available
|||Web presentations of the 1964, 1991 and 1998 versions are
|||The DDC 510 revision proposal presented by Giles Martin is
for related topics in the field of hypertext functionality, see the whole special issue of "Journal of Digital Information", [JoDI99]
see the homepage of the Padua Logic Group, at
|AGB97||J. Aitchison, A. Gilchrist, D. Bawden|
"Thesaurus construction: a practical manual", 3rd ed., ASLIB, 1997
|BJR98||G. Booch, L. Jacobson, J. Rumbaugh|
"The Unified Modeling Language User Guide", Addison-Wesley, 1998
Networked Knowledge Representation and Exchange using UML and RDF
"Journal of Digital Information", 1(8), 2001
|CCMS96||L.M. Chan, J.P. Comaromi, J.S. Mitchell, M.P.
"Dewey Decimal Classification: a practical guide. 2nd ed., revised for DDC 21", OCLC Online Computer Library Center, 1996
|CDLNR98||D. Calvanese, G. De Giacomo, M. Lenzerini, D. Nardi, R.
Description logic framework for information integration
"Proceedings of the 6th International Conference on the Principles of Knowledge Representation and Reasoning (KR'98)", Morgan Kaufman, 1998. p. 2-13
|CSSV||T. Coquand, G. Sambin, J. Smith, S.
Inductively generated formal topologies
Semantic Problems of Thesaurus Mapping
"Journal of Digital Information", 1(8), 2001
|F96||A.C. Foskett |
"The Subject Approach to Information", 5th ed., Library Association Publishing, 1996
|FOIS98||"Formal Ontology in Information Systems: proceedings of FOIS'98", N. Guarino (ed.), IOS Press, 1998|
Some Ontological Principles for Designing Upper Level Lexical Resources
"Proceedings of the First International Conference on Lexical Resources and Evaluation, Granada, Spain, 28-30 May 1998"
The role of Identity Conditions in Ontology Design
"Proceedings of the IJCAI-99 Workshop on Ontology and Problem Solving Methods (KRRS), Stockholm, Sweden, August 2, 1999"
Republished in "Spatial Information Theory: Cognitive and Computational Foundations of Geographic Information Science", C. Freksa and D. M. Frank (eds.), Springer Verlag, 1999
|GMV99||N. Guarino, C. Masolo, G. Vetere|
Ontoseek: Content-based Access to the Web
"IEEE Intelligent Systems", 14(3), 1999. p. 70-80
|GW00||N. Guarino, C. Welty|
Ontological Analysis of Taxonomic Relationships
"Proceedings of ER-2000: The 19th International Conference on Conceptual Modeling", A. Laender, V. Storey (eds.), Springer Lecture Notes in Computer Science, 2000
|GW01||N. Guarino, C. Welty|
Identity and Subsumption
Ladseb Internal Report 01/2001
MetaNet - A Metadata Term Thesaurus to Enable Semantic Interoperability Between Metadata Domains
"Journal of Digital Information", 1(8), 2001
|JoDI99||"Journal of Digital Information" - Vol. 1, Issue 4:
|JoDI01||"Journal of Digital Information" - Vol. 1, Issue 8:
"Networked Knowledge Organization Systems"|
|JoLC99||"Journal of Logic and Computation" - Vol. 9, No. 3: "Special Issue on Description Logics"|
|KW01||T. Krichel, S. Warner|
Vocabulary for the Academic Metadata Format, draft
|RSG99||G. Rossi, D. Schwabe, A. Garrido|
Designing Computational Hypermedia Applications
"Journal of Digital Information", 1(4), 1999
"Conceptual Structures: Information Processing in Minds and Machines", Addison-Wesley, 1984
"The Intellectual Foundations of Information Organization", MIT Press, 2000
|SG99||G. Sambin, S. Gebellato|
A preview of the basic picture: a new perspective on formal topology
Proceedings of "Types '98", T. Altenkirch, W. Naraschewski and B. Reus (eds.), Springer Lecture Notes in Computer Science, 1999
|TAJ01||D. Tudhope, H. Alani, C. Jones|
Augmenting Thesaurus Relationships: Possibilities for Retrieval
"Journal of Digital Information", 1(8), 2001
Formal Topology and Search Engine
|WJ99||C. Welty, J. Jenkins|
Formal Ontology for Subject
"Data and Knowledge Engineering", 31(2), 1999. p. 155-182
Biblioteca del Seminario Matematico
Universit` degli Studi di Padova
Home Page: http://www.iami.mi.cnr.it/~alberto/
Istituto per le Applicazioni della Matematica e dell'Informatica
Consiglio Nazionale delle Ricerche (IAMI-CNR), Milano
For citation purposes:
Antonella De Robbio, Dario Maguolo, Alberto Marini, "Scientific and General Subject Classifications in the Digital World", High Energy Physics Libraries Webzine, issue 5, November 2001