A New Formal Context for Symmetric Dependencies

In this paper we present a new formal context for symmetric dependencies. We study its properties and compare it with previous approaches. We also discuss how this new context may open the door to solve some open problems for symmetric dependencies.Postprint (published version

Workshop NotesInternational Workshop ``What can FCA do for Artificial Intelligence?'' (FCA4AI 2015)

International audienceThis volume includes the proceedings of the fourth edition of the FCA4AI --What can FCA do for Artificial Intelligence?-- Workshop co-located with the IJCAI 2015 Conference in Buenos Aires (Argentina). Formal Concept Analysis (FCA) is a mathematically well-founded theory aimed at data analysis and classification. FCA allows one to build a concept lattice and a system of dependencies (implications) which can be used for many AI needs, e.g. knowledge discovery, learning, knowledge representation, reasoning, ontology engineering, as well as information retrieval and text processing. There are many ``natural links'' between FCA and AI, and the present workshop is organized for discussing about these links and more generally for improving the links between knowledge discovery based on FCA and knowledge management in artificial intelligence

From Domain Models to Components - A Formal Transformation Approach Towards Dependable Software Development

Many academic, industrial, and government research units have unanimously acknowledged the importance of developing dependable software systems. At the same time they have also concurred on the difficulties and challenges to be surmounted in achieving the goal. The importance of domain analysis and linking domain models to software artifacts were also recognized by various researchers. However, no formal approach to domain analysis was attempted. The primary motivation for this thesis stems from this context. Component-based software engineering offers some attractive mechanisms to tackle the inherent complexity in developing dependable systems. Recently a formal approach has been put forth for such a development. This thesis provides a formal approach for domain analysis, and transforms the domain model to components desired by this development process. Formal Concept Analysis (FCA) is a mathematical theory for identifying and classifying concepts. This thesis taps its potential to formally analyze the domain in a software development context. It turns out that the approach presented in this thesis cannot be fully automated; nevertheless several useful contributions have been made. These include (1) capturing formal concepts and defining them in FCA; (2) defining composition rules to categorize formal concepts and their trustworthy properties; (3) integrating partial formal context tables to build the concept lattice; (4) specifying and developing a model transformation approach to construct trustworthy OWL ontology; (5) implementing a model transformation technique to generate the TADL specification of the reusable component-based system. The proposed approach is applied to CoCoME, as a benchmark case study in the domain of component-based development

Ontology development from the encyclopaedic organization of knowledge

Globalna mreža, internet, ubrzano se transformira u semantičku mrežu prelazeći od povezivanja dokumenata na povezivanje podataka, odnosno dosadašnji web portali s klasičnim bazama informacija i znanja postaju povezani podaci (engl. linked data) globalnog oblaka (engl. cloud computing). Usporedbom organizacijske strukture tradicionalnih enciklopedija na papirnatom mediju s onima u mrežnom okruženju uočavaju se određene razlike proizašle iz različitih vrsta medija koje omogućavaju nove funkcionalnosti pretraživanja. Promjene kroz koje prolazi enciklopedičko djelo zahtijeva uspostavljanje novog načina modeliranja organizacije enciklopedičkog znanja u mrežnom okruženju koje će svoje utemeljenje pronaći na analizi specifičnosti strukture enciklopedičkog članka uvažavanjem temeljnih postavki semantičkog weba, principa ontologijskog oblikovanja i potreba korisnika kako bi se osigurala njihova dostupnost i bolja iskoristivost. U svrhu očuvanja korisnosti enciklopedije u današnjoj mrežnoj informacijskoj eksploziji potrebno je poboljšati sposobnost predstavljanja njihovog sadržaja na smisleni (semantički) način u mrežnom okruženju. Cilj ove doktorske disertacije je istražiti koji elementi enciklopedičke organizacije znanja mogu pružiti podršku za razvoj ontologije te razviti metodu kojom će se generirati ontologija na osnovi enciklopedički organiziranog znanja. Proučavanjem literature, analizom sličnih ontologijskih modela odabranih svjetskih projekata i znanja pohranjenog u biografskim člancima Hrvatske enciklopedije (HE) iz područja hrvatske književnosti predložio se ontologijski model koji na djelotvoran način opisuje enciklopedičko znanje navedenog područja. Primijenjena je metodologija analize sadržaja odabranih 1170 članaka HE te METHONTOLOGY metoda. Upotrijebio se Protege softver za razvoj ontologije. Klasna hijerarhija ontologije se razvija FCA pristupom te se provodi LSA metoda u svrhu određivanja pojma kao skupa srodnih termina te pripadnosti pojedinih dokumenta (članaka) tom pojmu, čime je omogućena automatska klasifikacija članaka pojedinim ontologijskim klasama. Razvijena ontologija poslužit će za organizaciju, pretraživanje i pregledavanje znanja mrežne HE iz odabranog područja hrvatske književnosti, kao i za dobivanje preciznih odgovora na složena pitanja. Obuhvaćen je veliki broj odnosa potreban za opis produkcije književnika pojedinih nacionalnih književnosti, njihovih životopisa, međusobnih odnosa, odnosa između pojedinih književnih djela i cjelokupnog znanja koje se nalazi u biografskim enciklopedijskim člancima iz područja književnosti čime se omogućuje opis književnosti bilo kojeg naroda. Dobivena ontologija omogućuje uspostavljanje interoperabilnosti i povezivanje s ostalim strukturiranim izvorima enciklopedijskog znanja na semantičkoj mreži (npr. DBpedia), što će omogućiti povezivanje relevantnog i bogatog znanja HE u „globalnu mrežu znanja“ koja nastaje i razvija se kroz projekte semantičke mreže.The global network, the Internet, is hurriedly tranforming into an semantic network by turning from document connection onto data connection, i.e. today's WEB portals with classic information databases are becoming linked data of global computing. By comparing organisational structures of traditional encyclopedias on paper media with electronical encyclopedias in Web surroundings, you can notice certain differences that come from different types of media which enable new functionalities of searching. The above mentioned changes, through which an encyclopedical work passes through, demands an establishment of a new way of modeling organisation of encyclopedical knowledge in a Web surrounding that will find its foundation on the analysis of the specificity of a structure of an encyclopedical chapter by respecting the basic settings of the Semantic Web, principles of ontological shaping and needs of users so their availability and usability would be ensured. With the aim of preserving encyclopedical usability in today's Web information explosion, there is a need of modifying presentation of its content in a meaningful (semantic way) in a Web surrounding. Semantic interoperability means an existence of infrastructure which will enable mechanical interpretation and conclusion about content on the Web. Therefore, the key term of Semantic Web is presented by ontology, the basic component in enabling semantic interoperability. The aim of this doctoral thesis is to find out which elements of encyclopedical knowledge organisation can offer support for the development of ontology and develop a method by which ontology will be generated on the basis of encyclopedically organised knowledge. Developed ontology will be used for organisation, searching and browsing data of Croatia's Web Encyclopedia in the selected field of Croatian literature, as well as receiving precise answers on asked questions. In the introductory part of this work are presented its starting points, goals and methods, as well as the structure of the entire work. The second chapter deals with a theoretical display and clarification os Semantic Web with the aim of its full understanding. The goal of this chapter is to point out the basic theoretical and technical background of Semantic Web, the meaning of the term Semantic Web is explained, basic difference between the Web we know today and its development toward Semantic Web, disadvantages of today's Web and advantages of Semantic Web are explained, basic terms and the architecture of Semantic Web, review of basic ontologic definitions and their main goal and role. The chapter gives a detailed review of basic languages used on the semantic web with actual examples (RDF, RDFS; OWL and SKOS). Some of the more important projects of Semantic Web are shown in the third chapter of the work. During the selection of significant projects, it was considered to choose projects which are significant for better understanding of Semantic Web in the field of encyclopedics. That is why one part of this chapter deals with showing ontologies unavoidable for better understanding of Semantic Web, and the other part of the chapter gives a review of ontologic projects created entirely on encyclopedical knowledge. The mentioned analysis of existing encyclopedical ontological projects shows that no former project did try to connect and research the development of ontology and its constructive elements on the basis of structural organisation of the encyclopedial chapter by researching significance of individual structural elements of an encyclopedical chapter for the development of ontology. The fourth chapter is an introduction to the development of the ontological model of literature and to the basic settings of Protégé software. Elements of standards and ontologic languages (i.e. vocabularies RDFS, OWL, SKOKS) are shown and applied in the development of ontology of Croatian Encyclopedia in the field of Croatian literature. Pointed out was the possibility of reaching interoperability inasmuch individual ontologic resources, as well as overall ontology, with existing semantic ontologic projects on the Semantic Web which will allow conneting relevant and rich knowledge of Croatian Encyclopedia into an „global network of knowledge“ which appears and develops through projects of Semantic Web. The fifth chapter gave an insight into the historical development of encyclopedia in the world so people could completely realize the context through which encyclopedia had to go through in other to gain today's familiar features of a modern encyclopedistic work. The chapter has given basic information about the development of the Croatian central lexicographical institution; Lexicographical institution „Miroslav Krleža“ (LZMK) that does lexicography and encyclopedics of particular interest for the Republic of Croatia. It is shown that this doctoral thesis can contribute to ,with some particular elements , realising the mission and vision of LZMK. Publishing work of basic and expert enyclopedic editions of LZMK is shown, embracing editions on a paper media and those in a web surrounding. By analysing publishing work of web editions, it was found that their substantiation was mostly a matter of adapting traditional organisations of encyclopedic knowledge from paper media to web surroundings. That is why this doctoral thesis will research which uses from applying ontologic principles of semantic web would LZMK have, as well as users of these valuable knowledge sources. The sixth chapter has shown a structural organisation of encyclopedical articles, looking back onto basic types of encyclopedic articles and especially on features of biographic encyclopedial article that is the basis of research of this work. An analysis of type of data which contain encyclopedical biographic articles has been done. The mentioned allowed establishing basic ontologic layers i.e. facets by which ontologic relations will classify. The seventh chapter identifies constructive ontologic elements from encyclopedical biographic article, shows the metodology used in development of ontology, as well as resulting conceptual taxonomy and ontologic relations. The chapter has shown the role of structural elements of encyclopedical biographic article during ontologic development and connected them to corresponding constructive ontologic elements. The results of the research are presented through display of ontologic modules and belonging ontologic relations that can be used in describing a certain term. A display of structure and sequence of elements of encylopedical biographic article has been shown, with developed ontologic features by which can all types of information in the article be stored, from which constant elements have been determined that can be perceived for development of article infoframes, which is suitable for a quick insight into most important information of individual articles. Final results are shown through application of the gained ontology in description of an individual, as well as through possibility of installing complex semantic questions by unstructured data of encyclopedical biographic articles and through the possibility of organising browsing encyclopedical data, which hasn't been possible until now. The eight chapter explained the FCA approach applied during building of ontology so a gathering of conceptual features would be established, by which terms in ontology were defined so classification of terms could be made into a hierarchy. Important definitions were emphasized to understand places of formal term analysis in methodology of creating ontology. An actual example of accomplishing FCA approach was shown in 37 articles of Croatian literature in Croatian Encyclopedia, as well as a transformation of a transformational grid into a formal language of first order logics. Chapter shows the advantages of applying FCA analysis because of generating new and unfamilliar terms which could be hardly established only by handiwork of ontology, because texts specific to the domain do not include any kind of noun phrase for labeling these new terms. The ninth chapter brings out problems of automated indexing methods and information fetching. Theoretically, it shows the LSA method and its application on the example of encyclopedical articles of Croatian Encyclopedia with the goal of learning about its effieciency and goals in building ontology of an certain area. Conducting LSA method on chosen articles shows its utility in assessing the term as a gathering of related terms and affiliations of certain entries of articles (documents) in that matter, by which on the basis of word forms that selected articles consist of allows an automatic classification of articles by individual ontologic classes. The tenth, also final, chapter of this work is a conclusion which combines theoretical and practical part of the work by giving a short review of research results and showing the possibility of establishing interoperability and connecting Linked Data concept of Croatian encyclopedistics with other structural sources of encyclopedical knowledge on the web ( e.g. DBpedia, Freebase, etc.)

AVATAR - Machine Learning Pipeline Evaluation Using Surrogate Model

© 2020, The Author(s). The evaluation of machine learning (ML) pipelines is essential during automatic ML pipeline composition and optimisation. The previous methods such as Bayesian-based and genetic-based optimisation, which are implemented in Auto-Weka, Auto-sklearn and TPOT, evaluate pipelines by executing them. Therefore, the pipeline composition and optimisation of these methods requires a tremendous amount of time that prevents them from exploring complex pipelines to find better predictive models. To further explore this research challenge, we have conducted experiments showing that many of the generated pipelines are invalid, and it is unnecessary to execute them to find out whether they are good pipelines. To address this issue, we propose a novel method to evaluate the validity of ML pipelines using a surrogate model (AVATAR). The AVATAR enables to accelerate automatic ML pipeline composition and optimisation by quickly ignoring invalid pipelines. Our experiments show that the AVATAR is more efficient in evaluating complex pipelines in comparison with the traditional evaluation approaches requiring their execution