Thesaurus Relationships Research Articles

Тезаурусы по физике и электронике для навигации по цифровому пространству знаний

The article describes the principles and experience of building brach thesauri designed to represent subject areas within the formal ontology of the unified knowledge space. Ttrms jf the thesauri include the words that are actually used for thematic indexing of documents — keywords and classification categories. The system of the thesaurus relations is established by a semi-automatic procedure and includes: equivalence (synonymy), generic hierarchy, association, and definitive relationship.

Analysis of Influence of Different Relations Types on the Quality of Thesaurus Application to Text Classification Problems

The main purpose of the article is to analyze how effectively different types of thesaurus relations can be used for solutions of text classification tasks. The basis of the study is an automatically generated thesaurus of a domain, that contains three types of relations: synonymous, hierarchical and associative. To generate the thesaurus the authors use a hybrid method based on several linguistic and statistical algorithms for extraction of semantic relations. The method allows to create a thesaurus with a sufficiently large number of terms and relations among them. The authors consider two problems: topical text classification and sentiment classification of large newspaper articles. To solve them, the authors developed two approaches that complement standard algorithms with a procedure that take into account thesaurus relations to determine semantic features of texts. The approach to topical classification includes the standard unsupervised BM25 algorithm and the procedure, that take into account synonymous and hierarchical relations of the thesaurus of the domain. The approach to sentiment classification consists of two steps. At the first step, a thesaurus is created, whose terms weight polarities are calculated depending on the term occurrences in the training set or on the weights of related thesaurus terms. At the second step, the thesaurus is used to compute the features of words from texts and to classify texts by the algorithm SVM or Naive Bayes. In experiments with text corpora BBCSport, Reuters, PubMed and the corpus of articles about American immigrants, the authors varied the types of thesaurus relations that are involved in the classification and the degree of their use. The results of the experiments make it possible to evaluate the efficiency of the application of thesaurus relations for classification of raw texts and to determine under what conditions certain relations affect more or less. In particular, the most useful thesaurus relations are synonymous and hierarchical, as they provide a better quality of classification.

RussianLanguage Thesauri: Automated Construction and Application For Natural Language Processing Tasks

The paper reviews the existing Russian-language thesauri in digital form and methods of their automatic construction and application. The authors analyzed the main characteristics of open access thesauri for scientific research, evaluated trends of their development, and their effectiveness in solving natural language processing tasks. The statistical and linguistic methods of thesaurus construction that allow to automate the development and reduce labor costs of expert linguists were studied. In particular, the authors considered algorithms for extracting keywords and semantic thesaurus relationships of all types, as well as the quality of thesauri generated with the use of these tools. To illustrate features of various methods for constructing thesaurus relationships, the authors developed a combined method that generates a specialized thesaurus fully automatically taking into account a text corpus in a particular domain and several existing linguistic resources. With the proposed method, experiments were conducted with two Russian-language text corpora from two subject areas: articles about migrants and tweets. The resulting thesauri were assessed by using an integrated assessment developed in the previous authors’ study that allows to analyze various aspects of the thesaurus and the quality of the generation methods. The analysis revealed the main advantages and disadvantages of various approaches to the construction of thesauri and the extraction of semantic relationships of different types, as well as made it possible to determine directions for future study.

Relations in KOS: is it possible to couple a common nature with different roles?

PurposeThe purpose of this paper, which increases and deepens what was expressed in a previous work (Mazzocchi et al., 2007), is to scrutinize the underlying assumptions of the types of relations included in thesauri, particularly the genus-species relation. Logicist approaches to information organization, which are still dominant, will be compared with hermeneutically oriented approaches. In the light of these approaches, the nature and features of the relations, and what the notion of a priori could possibly mean with regard to them, are examined, together with the implications for designing and implementing knowledge organizations systems (KOS).Design/methodology/approachThe inquiry is based on how the relations are described in literature, engaging in particular a discussion with Hjørland (2015) and Svenonius (2004). The philosophical roots of today’s leading views are briefly illustrated, in order to put them under perspective and deconstruct the uncritical reception of their authority. To corroborate the discussion a semantic analysis of specific terms and relations is provided too.FindingsAll relations should be seen as “perspectival” (not as a priori). On the other hand, different types of relations, depending on the conceptual features of the terms involved, can hold a different degree of “stability.” On this basis, they could be used to address different information concerns (e.g. interoperability vs expressiveness).Research limitations/implicationsSome arguments that the paper puts forth at the conceptual level need to be tested in application contexts.Originality/valueThis paper considers that the standpoint of logic and of hermeneutic (usually seen as conflicting) are both significant for information organization, and could be pragmatically integrated. In accordance with this view, an extension of thesaurus relations’ set is advised, meaning that perspective hierarchical relations (i.e. relations that are not logically based but function contingently) should be also included in such a set.

Analysis of Influence of Different Relations Types on the Quality of Thesaurus Application to Text Classification Problems

The main purpose of the article is to analyze how effectively different types of thesaurus relations can be used for solutions of text classification tasks. The basis of the study is an automatically generated thesaurus of a subject area, that contains three types of relations: synonymous, hierarchical and associative. To generate the thesaurus the authors use a hybrid method based on several linguistic and statistical algorithms for extraction of semantic relations. The method allows to create a thesaurus with a sufficiently large number of terms and relations among them. The authors consider two problems: topical text classification and sentiment classification of large newspaper articles. To solve them, the authors developed two approaches that complement standard algorithms with a procedure that take into account thesaurus relations to determine semantic features of texts. The approach to topical classification includes the standard unsupervised BM25 algorithm and the procedure, that take into account synonymous and hierarchical relations of the thesaurus of the subject area. The approach to sentiment classification consists of two steps. At the first step, a thesaurus is created, whose terms weight polarities are calculated depending on the term occurrences in the training set or on the weights of related thesaurus terms. At the second step, the thesaurus is used to compute the features of words from texts and to classify texts by the algorithm SVM or Naive Bayes. In experiments with text corpora BBCSport, Reuters, PubMed and the corpus of articles about American immigrants, the authors varied the types of thesaurus relations that are involved in the classification and the degree of their use. The results of the experiments make it possible to evaluate the efficiency of the application of thesaurus relations for classification of raw texts and to determine under what conditions certain relationships affect more or less. In particular, the most useful thesaurus connections are synonymous and hierarchical, as they provide a better quality of classification.

Relationships and relata in ontologies and thesauri: Differences and similarities

Ontologies and thesauri structure concepts and, from the perspective of a practitioner, do not appear to be very different. Nevertheless, experts acknowledge that ontologies are different from thesauri in several respects. In this paper we aim to clarify some of the similarities and differences by systematically comparing the structure of each: the relations and their relata in ontologies and the relationships and their relata in thesauri. In particular, we analyze thesaurus relationships and their relata as they are defined in the latest version of the international ISO thesaurus standard against formally well-defined ontological relationships and relata from ontology literature --more specifically ontology literature based in realism. We have found that the relata as well as the relationships in thesauri need to be classified further before any reasonable matching to formal ontological relationships is possible. Isolated hierarchical relationships in thesauri then may correspond to the is-a relationship, specific mereological relationships, or fundamental relationships such as the instantiation between universals and individuals in ontologies. Determining how such correspondences apply in domain-specific cases depends on whether the thesaurus relationships contribute to the specifications of necessary and sufficient conditions for their respective relata in the ontology --a function that relationships do not have in thesauri. Our findings make it clear that thesauri require structural and definitional reengineering in order to be reused or treated as ontologies, but that adherence to the international standard for thesauri provides a good base for such reengineering.

신학 시소러스 구축에 관한 연구

신학 시소러스의 개념 관계를 구축하기 위해서 용어를 영어 신학사전과 성경에서 주로 추출하였다. 추출한 용어들을 대상으로 시소러스의 가장 기본적인 관계 유형인 등가관계, 계층관계, 연관관계를 구축하였다. 등가 관계에서 특징적인 것은 히브리어, 그리스어, 라틴어 우선어가 포함되었으며, 계층관계에서는 속종관계, 사례관계, 전체-부분 관계, 다중계층 관계로 세분화되었다. 또한 신학 시소러스의 개념 관계의 유형에 있어서는 다른 주제 영역의 시소러스와 큰 차이를 보이지는 않았다. 이 논문에서는 성경 신학과 연관된 관계 유형의 실제 사례들을 주로 제시하였다. 그 이유는 성경 신학이 성경과 기독교 신학 전체를 포괄적인 관점에서 파악할 수 있는 장점이 있기 때문이다. 이와 관련해서 신학 시소러스의 개념 관계의 특징 중의 하나는 비유적 표현의 용어가 상당히 많았다는 점이다. 이러한 결과가 나온 주된 이유는 구약에서 예표된 내용이 신약에서 성취되는 성경의 핵심적 구조 때문이다.

OWL exports from a full thesaurus

Le Web semantique consiste en une serie d'initiatives destinees a rendre les ressources du Web davantage accessibles aux agents logiciels, de facon a ce que ces agents puissent realiser au moins une analyse et un traitement de l'information rudimentaires. L'A. presente ici l'une de ces initiatives, le langage OWL (Web Ontology Language), en relation avec les thesaurus et les taxonomies. En depit de la complexite et de l'ampleur du projet, il y aura un Web semantique et OWL y jouera un role.

Integrating thesaurus relationships into search and browse in an online photograph collection

PurposeSeeks to share with digital library practitioners the development process of an online image collection that integrates the syndetic structure of a controlled vocabulary to improve end‐user search and browse functionality.Design/methodology/approachSurveys controlled vocabulary structures and their utility for catalogers and end‐users. Reviews research literature and usability findings that informed the specifications for integration of the controlled vocabulary structure into search and browse functionality. Discusses database functions facilitating query expansion using a controlled vocabulary structure, and web application handling of user queries and results display. Concludes with a discussion of open‐source alternatives and reuse of database and application components in other environments.FindingsAffirms that structured forms of browse and search can be successfully integrated into digital collections to significantly improve the user's discovery experience. Establishes ways in which the technologies used in implementing enhanced search and browse functionality can be abstracted to work in other digital collection environments.Originality/valueSignificant amounts of research on integrating thesauri structures into search and browse functionalities exist, but examples of online resources that have implemented this approach are few in comparison. The online image collection surveyed in this paper can serve as a model to other designers of digital library resources for integrating controlled vocabularies and metadata structures into more dynamic search and browse functionality for end‐users.

Automated assistance in the formulation of search statements for bibliographic databases

We report on the design and construction of features of an automated query system which will assist pharmacologists who are not information specialists to access the Derwent Drug File (DDF) pharmacological database. Our approach was to first elucidate those search skills of the search intermediary which might prove tractable to automation. Modules were then produced which assist in the three important subtasks of search statement generation, namely vocabulary selection, the choice of context indicators and query reformulation. Vocabulary selection is facilitated by approximate string matching, morphological analysis, browsing and menu searching. The context of the study, such as treatment or metabolism, is determined using a system of advisory menus. The task of query reformulation is performed using user feedback on retrieved documents, thesaurus relations between document index terms and term postings data. Use is made of diverse information sources, including electronic forms of printed search aids, a thesaurus and a medical dictionary. The system will be of use both to semicasual users and experienced intermediaries. Many of the ideas developed should prove transportable to domains other than pharmacology: the techniques for thesaurus manipulation are designed for use with any hierarchical thesaurus.