Description logics

Research on multimedia information retrieval (MIR) has recently witnessed a booming interest. A prominent feature of this research trend is its simultaneous but independent materialization within several fields of computer science. The resulting richness of paradigms, methods and systems may, on the long run, result in a fragmentation of efforts and slow down progress. The primary goal of this study is to promote an integration of methods and techniques for MIR by contributing a conceptual model that encompasses in a unified and coherent perspective the many efforts that are being produced under the label of MIR. The model offers a retrieval capability that spans two media, text and images, but also several dimensions: form, content and structure. In this way, it reconciles similarity-based methods with semantics-based ones, providing the guidelines for the design of systems that are able to provide a generalized multimedia retrieval service, in which the existing forms of retrieval...

From networks to Description Logics 8 1.3 Knowledge representation in Description Logics 16 1.4 From theory to practice: Description Logics systems 20 1.5 Applications developed with Description Logics systems 24 1.6 Extensions of Description Logics 34 1.7 Relationship to other fields of Computer Science 40 1.8 Conclusion 43 Part one: Theory 45 2 Basic Description Logics F. Baader, W. Nutt 47 2.1 Introduction 47 2.2 Definition of the basic formalism 50 2.3 Reasoning algorithms 78 2.4 Language extensions 95 3 Complexity of Reasoning F. M. Donini 101 3.1

This text provides a brief overview of selected structures aimed at knowledge representation in the form of ontologies based on description logic and aims at comparing them with their counterparts based on the rule-based approach. Due to the limitations on the length of the article, only elements associated with the representation of concepts could be shown, without including roles. The formalisms of the OWL language were used to record ontologies, while the rules were expressed in Prolog.

SF co-developer Steve de Shazer wrote, in his classic publications Keys to Solution in Brief Therapy (1985) and Clues: Investigating Solutions in Brief Therapy (1988), that SF practitioners should help their clients create an expectation of beneficial change by getting a description of what they would do differently once the problem was solved. Also, he claimed subtle and implicit interventions by the SF practitioner would work best. At the time, de Shazer did not support these claims with empirical evidence. This article provides evidence for each of the assertions made by de Shazer. Only part of the evidence presented here was already available at the time of de Shazer’s writing. Evidence is discussed from diverse lines of research like Rosenthal’s Pygmalion studies, Dweck’s research on self-theories, Fredrickson’s broaden-and-build theory, research on Winograd’s prospective memory, Jeannerod’s research on the perception-action link, Wilson’s research on brief attributional interventions, research on Brehm’s reactance theory, and Bargh’s research on priming. The article closes with some reflections on what these research findings imply for SF theory and practice.

D’emblée, Bernardo Secchi avait positionné la description au coeur du projet pour le territoire, proposant avec Paola Viganò un déplacement conceptuel de l’activité de l’urbaniste, depuis une réponse sectorielle à la demande sociale vers une activité de recherche originale. Liant de cette manière projet et recherche, il confère à cette dernière une dimension opérationnelle qui acquiert une importance toute particulière pour des territoires peu ou non pris en compte, ni même reconnus par la puissance publique. Secchi le démontra longuement pour la Città diffusa.
Mon intervention propose la présentation d’une recherche sur le territoire de Kinshasa, capitale de plus de 12 millions d’habitants de la République Démocratique du Congo, pays continent qui en compte 85 millions. L’enjeu de cette recherche est d’examiner comment peut se concevoir un projet pour le territoire kinois en absence de toute technostructure et moyens publics pour le mettre en œuvre. Elle jauge par là la portée opérationnelle de la description, soit comment le projet peut à la fois documenter ce territoire et permettre la construction de lignes possibles de raisonnement (Secchi, 2006) et d’action.
Ce travail de problématisation du territoire kinois est une étude personnelle en cours menée afin d’accompagner un ensemble de recherches doctorales menées des chercheurs congolais, dans le cadre de deux programmes de coopérations universitaires coordonnés par la Faculté d’architecture de l’ULB. Il se base sur une approche de Kinshasa à travers 3 images et une hypothèse de lecture fondamentale —celle de la Mboka Bilanga, termes que le caractère très polysémique du lingala permet de traduire par ville maraîchaire/spontanée/émancipatrice—, pour aborder de manière synthètique mais non englobante un territoire aux limites floues sans en éluder sa complexité et décliner une série de recherches spécifiques à l’intérieur d’un récit collectif porteur d’espoir d’actions concrètes à court et moyen terme sur la ville.

Most recently, the concept of business documents has started to play double role. On one hand, a business document
(word processing text or calculation sheet) can be used as specification tool, on the other hand the business document is
an immanent constituent of business processes, thereby essential component of business information systems. The
recent tendency is that the majority of documents and their contents within business information systems remain in
semi-structured format and a lesser part of documents is transformed into schemas of structured databases. In order to
keep the emerging situation in hand, we suggest the creation (1) a theoretical framework for modeling business
Information Systems and (2) a design method for practical application based on the theoretical model that provides the
structuring principles. The modeling approach that focuses on documents and their interrelationships with business
processes assists in perceiving the activities of modern information systems.

Critica literară între nega ia de sine i silogismele angoasei ț ș Aluni a Cofan ț Résumé: Nous faisons une analyse approfondie du tome intitulé NON, écrit par un jeune frondeur, Eugéne Ionesco, contre la critique et la littérature roumaines, contre les valeurs immuables de la culture et la raison qui s'appuie sur les certitudes du syllogisme. En tenant compte de sa structure paradoxale, notre démarche herméneutique dévoile que la couche textuelle de surface de cet ouvrage cache, dans le profondeurs, des contradictions irréconciliables. Le lien du grotesque avec cet ouvrage se repose sur cette coexistence antagonique des contraires et sur la critique des valeurs (littéraires et culturelles) immuables. C'est une leçon de relativité et, en même temps, c'est la première fois qu'une définition du grotesque apparaît comme telle, en contentant même l'idée d'une contradiction en conflit. Mots-clés: la logique, le syllogisme, la raison, le grotesque illogique, Eugène Ionesco, l'ouvrage roumain de critique, le grotesque du paradoxe, herméneutique du grotesque, T. Arghezi, Nae Ionescu, la pensée Zen,

Учебное пособие «Введение в формальную семантику» подготовлено по материалам курсов «Методы программной реализации
интеллектуальных систем» (А.В. Андреев), «Математические модели языка», «Формальная и компьютерная семантика» (О.А. Митрофанова), «Понимание естественного языка» (К.В. Соколов).
Для студентов, изучающих дисциплины, связанные с формальными моделями и автоматичекой обработкой естественного
языка.

The workshop continues the long-standing tradition of international workshops devoted to discussing developments and applications of knowledge representation formalisms and systems based on Description Logics. The list of the International Workshops on Description Logics can be found at http://dl.kr.org.

Di dalam berbagai tulisan Nietzshe, Robert C.Solomon menemukan beberapa argumentasi dari Nietzsche yang bersifat ad hominem. Logika ad hominem adalah suatu teknis retoris yang sering dianggap sebagai "kekeliruan", penyerangan atas motif dan emosi dari keantagonisannya, dan bukan sangkalan atas ide.

In this paper we describe the principles of the design and development of an intelligent query interface, done in the context of the SEWASIE (SEmantic Webs and AgentS in Integrated Economies) European IST project. The SEWASIE project aims at enabling a uniform access to heterogeneous data sources through an integrated ontology. The query interface is meant to support a user in formulating a precise query–which best captures her/his information needs–even in the case of complete ignorance of the vocabulary of the ...

F elsefi düşünüş biçimi denildiğinde kavram, metodoloji ve kuramdan oluşan bütüncül bir sistem akla gelir. İslam filozofları da Tanrı-evren ve insan ilişkisine dair kendi sistemlerini oluştururken öncelikle kavramlarını ve metodolojik yaklaşımlarını ortaya koymaktadırlar. Kindî, Fârâbî ve İbn Sînâ merkezli çalışmaların bir araya getirilmesinin öncelikle amacı İslam felsefesinin teşekkül dönemini "Meşşai Gelenek" bağlamında anlamak, anlamlandırmak ve yeniden yorumlamaya katkı yapmaktır.

Ontologies play a crucial role in the development of the Semantic Web as a means for defining shared terms in web resources. They are formulated in web ontology languages, which are based on expressive description logics. Significant research efforts in the semantic web community are recently directed towards representing and reasoning with uncertainty and vagueness in ontologies for the Semantic Web. In this paper, we give an overview of approaches in this context to managing probabilistic uncertainty, possibilistic uncertainty, and vagueness in expressive description logics for the Semantic Web.

Description Logics (DLs) are gaining a widespread adoption as the popularity of the Semantic Web increases. Traditionally, reasoning algorithms for DLs have been implemented in procedural languages such as Java or C++. In this paper, we present the system TRILL for “Tableau Reasoner for descrIption Logics in proLog”. TRILL answers queries to SHOIN (D) knowledge bases using a tableau algorithm. Prolog nondeterminism is used for easily handling non-deterministic expansion rules that produce more than one tableau. Moreover, given a query, TRILL is able to return instantiated explanations for the query, i.e., instantiated minimal sets of axioms that allow the entailment of the query. The Thea2 library is exploited by TRILL for parsing ontologies and for the internal Prolog representation of DL axioms.

Pertemuan 1  Berasal dari bahasa latin "Logos" yang berarti perkataan atau sabda  Istilah lain Logika dalah mantik (dari bahasa Arab) yang berarti berkata atau berucap  Dalam bahasa sehari-hari, kita sering mendengar ungkapan serupa: alasannya tidak logis, kabar itu tidak logis.

Tables, hierarchies and lists dominate the way we organize data. In the field of computing, tables are the gold standard. These categories can be seen as more than data structures : They form the superstructure of our thoughts, the footprint of understanding. This viewpoint warrants a detailed study. Why do we use the table so much, and why is our understanding of categories so limited?

Axiom weakening is a novel technique that allows for fine-grained repair of inconsistent ontologies. In a multi-agent setting, integrating ontologies corresponding to multiple agents may lead to inconsistencies. Such inconsistencies can be resolved after the integrated ontology has been built, or their generation can be prevented during ontology generation. We implement and compare these two approaches. First, we study how to repair an inconsistent ontology resulting from a voting-based aggre-gation of views of heterogeneous agents. Second, we prevent the generation of inconsistencies by letting the agents engage in a turn-based rational protocol about the axioms to be added to the integrated ontology. We instantiate the two approaches using real-world ontologies and compare them by measuring the levels of satisfaction of the agents w.r.t. the ontology obtained by the two procedures.

Le projet de représenter la sémantique des termes et concepts humains à l’aide de langages formels ne date pas d’hier, mais il connait aujourd’hui un regain d’intérêt avec le développement des ontologies computationnelles. Fer de lance du Web sémantique, la principale ambition de ces systèmes de représentation est de permettre aux machines d’accéder au « sens » des données qu’elles manipulent. Les langages formels ont toujours eu leurs détracteurs et l’usage qui en est fait en ingénierie ontologique ne fait pas exception. Différents auteurs dénoncent le projet de soumettre notre sémantique naïve à des formalismes logiques, trop rigides et trop mécaniques pour en capter la mobilité et l’adaptabilité, et proposent de leur substituer des approches et modèles alternatifs, censés être plus proches des mécanismes de conceptualisation et de représentation « naturels » de l’humain. L’objet de cet article est de montrer que ces critiques sont pour la plupart infondées, et en tout cas hors sujet, en ce qu’elles présupposent la subordination des ontologies à une exigence épistémique (modéliser de manière fidèle un référent) plutôt qu’opérationnelle (fonctionner et rendre service). Elles perdent leur raison d’être dès lors que l’on considère que la fonction des ontologies n’est pas (i) de représenter de manière fidèle le mobilier et les structures constitutives de la réalité (réalisme) ou la manière dont l’esprit se représente cette réalité (conceptualisme), mais (ii) d’augmenter les capacités de catégorisation, d’accès à l’information et de manipulation de données et documents, et (iii) de normaliser les pratiques de catégorisation et d’encodage. Considérer les ontologies computationnelles dans la perspective de l’augmentation cognitive et de l’instrumentation des pratiques exige un nouveau cadre épistémologique pour leur conception. Nous en décrivons ici les principes de base et proposons de qualifier cette nouvelle approche d’instrumentaliste.

A partir du paradoxe d'"une femme enfermant un pays" le filigrane mathématique de la Recherche du Temps perdu offre un paradigme de logique modale mathématisée à la mode d'Amsterdam, telle qu'elle est esquissée dans le commentaire de Proust par Deleuze.

As applications of description logics proliferate, efficient reasoning with knowledge bases containing many assertions becomes ever more important. For such cases, we developed a novel reasoning algorithm that reduces a \(\mathcal{SHIQ}\) knowledge base to a disjunctive datalog program while preserving the set of ground consequences. Queries can then be answered in the resulting program while reusing existing and practically proven optimization techniques of deductive databases, such as join-order optimizations or magic sets. Moreover, we use our algorithm to derive precise data complexity bounds: we show that \(\mathcal{SHIQ}\) is data complete for NP, and we identify an expressive fragment of \(\mathcal{SHIQ}\) with polynomial data complexity.

We introduce semantic artifacts, which are a mechanism that provides both a semantically rich representation of the information on the domain of interest in terms of an ontology, including the underlying data, and a set of actions to change such information over time. In this paper, the ontology is specified as a DL-Lite TBox together with an ABox that may contain both (known) constants and unknown individuals (labeled nulls, represented as Skolem terms). Actions are specified as sets of conditional effects, where conditions are based on conjunctive queries over the ontology (TBox and ABox), and effects are expressed in terms of new ABoxes. In this setting, which is obviously not finite state, we address the verification of temporal/dynamic properties expressed in µ-calculus. Notably, we show decidability of verification, under a suitable restriction inspired by the notion of acyclicity in data exchange.

In this paper we provide a semantic reconstruction of rational closure. We first consider rational closure as defined by Lehman and Magidor [33] for propositional logic, and we provide a semantic characterization based on a minimal models mechanism on rational models. Then we extend the whole formalism and semantics to Description Logics, by focusing our attention to the standard ALC: we first naturally adapt to Description Logics Lehman and Magidor's propositional rational closure, starting from an extension of ALC with a typicality operator T that selects the most typical instances of a concept C (hence T(C) stands for typical C). Then, for the Description Logics, we define a minimal model semantics for the logic ALC and we show that it provides a semantic characterization for the rational closure of a Knowledge base. We consider both the rational closure of the TBox and the rational closure of the ABox.

In almost all domains in practice, it is fundamental to properly represent entities amenable to changes. For instance, in business analytics, we must be able to reason with large amounts of time-changing KPI (key performance indicators) data. For this reason, general-purpose practical knowledge representation frameworks must be able to support the representation of temporally changing information and in a way that affords decidable automated reasoning. In this paper, we address the issue of representing entities amenable to intrinsic or extrinsic changes in OWL2. These sources of change are illustrated in a simplified model of the scholar domain. We then propose three strategies to represent entities amenable to changes as well as their changes. In particular, we do that by employing strategies that are based on a philosophical stance called perdurantism, which sees all individuals as 4D entities, i.e., as individuals that unfold in time as well as in space. Finally, we compare these three alternatives by generating synthetic instances and performing an empirical evaluation of reasoning tasks.

Kinship plays a fundamental role in human communities as a basic principle for organizing individuals into social groups. Representing kinship relationships in a formal and precise way is then a crucial task when modelling many knowledge domains, and it may constitute a relevant benchmark for the reasoning layer of the Semantic Web. In this paper we face the problem of representing some basic aspects of kinship relationships using the fragments of OWL2 corresponding to the description logics SROIQ and EL ++ . As a first step, we provide an intuitive but formal description of some kinship terms, using an expressive description logic. From this intuitive description, we derive a set of test cases, indicating the expected inferences that should be drawn from the candidate ontologies. Finally, three different ontologies (two for SROIQ and one for EL ++ ), whose coherence with the intuitive description of kinship terms is established, are compared by means of these test cases. 5 http://www.w3.org/standards/techs/rif#w3c_all 6 http://www.w3.org/TR/2009/REC-owl2-overview-20091027/

In recent years, there has been a growing interest in the application of foundational ontologies, i.e., formal ontological theories in the philosophical sense, to provide a theoretically sound foundation for improving the theory and practice of conceptual modeling and knowledge representation. This paper addresses one particular foundational theory of events termed UFO-B, which has been successfully employed as a reference model for addressing problems from complex media management, enterprise architecture, software engineering, and modeling of events in petroleum exploration. Despite that, there is still no formalization of UFO-B in a decidable knowledge representation language that could support reasoning about complex events and event relations. We address this gap by proposing a number of alternative translations from UFO-B's original axiomatization (in first-order logic and in the Alloy formal language) to the description logic SROIQ, which is the formal underpinning of OWL 2 DL. Additionally, to support practical applications, we translated these SROIQ theories to OWL 2 DL TBoxes, which were validated by showing that all the intended models of UFO-B (the logical models of the UFO-B specification in Alloy) that we generated are consistent with these UFO-B TBoxes.

UML is the de-facto standard formalism for software design and analysis. To support the design of large-scale industrial applications, sophisticated CASE tools are available on the market, that provide a user-friendly environment for editing, storing, and accessing multiple UML diagrams. It would be highly desirable to equip such CASE tools with automated reasoning capabilities, such as those studied in Artificial Intelligence and, in particular, in Knowledge Representation and Reasoning. Such capabilities would allow to automatically detect relevant formal properties of UML diagrams, such as inconsistencies or redundancies. With regard to this issue, we consider UML class diagrams, which are one of the most important components of UML, and we address the problem of reasoning on such diagrams. We resort to several results developed in the field of Knowledge Representation and Reasoning, regarding Description Logics (DLs), a family of logics that admit decidable reasoning procedures. Our first contribution is to show that reasoning on UML class diagrams is EXPTIMEhard, even under restrictive assumptions; we prove this result by showing a polynomial reduction from reasoning in DLs. The second contribution consists in establishing EXPTIME-membership of reasoning on UML class diagrams, provided that the use of arbitrary OCL (first-order) constraints is disallowed. We get this result by using DLR ifd , a very expressive EXPTIME-decidable DL that has been developed to capture typical features of conceptual and object-oriented data models. The last contribution has a more practical flavor, and consists in a polynomial encoding of UML class diagrams in the DL ALCQI, which essentially is the most expressive DL supported by current state-of-the-art DL-based reasoning systems. Though less expressive than DLR ifd , the DL ALCQI et al. / Artificial Intelligence 168 (2005) 70-118 71 preserves enough semantics to keep reasoning about UML class diagrams sound and complete. Exploiting such an encoding, one can use current DL-based reasoning systems as core reasoning engines for a next generation of CASE tools, that are equipped with reasoning capabilities on UML class diagrams. In this paper we deal with UML class diagrams for the conceptual perspective, as opposed to the implementation perspective, see, e.g., [1].

Mathematical Fuzzy Logic Propositional and predicate t-norm based fuzzy logics Truth constants a b s t r a c t Description Logics (DLs) are knowledge representation languages built on the basis of classical logic. DLs allow the creation of knowledge bases and provide ways to reason on the contents of these bases. Fuzzy Description Logics (FDLs) are natural extensions of DLs for dealing with vague concepts, commonly present in real applications.

Ontology construction in OWL is an important and yet time-consuming task even for knowledge engineers and thus a (semi-) automatic approach will greatly assist in constructing ontologies. In this paper, we propose a novel approach to learning concept definitions in EL++ from a collection of assertions. Our approach is based on both refinement operator in inductive logic programming and reinforcement learning algorithm. The use of reinforcement learning significantly reduces the search space of candidate concepts. Besides, we present an experimental evaluation of constructing a family ontology. The results show that our approach is competitive with an existing learning system for EL.

We study ALCKm and ALCS4m, which extend the description logic ALC by adding modal operators of the basic multi-modal logics Km and S4m. We develop a sound and complete tableau algorithm ΛK for answering ALCKm queries w.r.t. an ALCKm knowledge base with an acyclic TBox. Defining tableau expansion rules in the presence of acyclic definitions by considering only the concept names on the left-hand side of TBox definitions or their negations, we are able to give a PSpace implementa- tion for ΛK. We then consider answering ALCS4m queries w.r.t. an ALCS4m knowl- edge base (with an acyclic TBox) in which the epistemic operators correspond to those of classical multi-modal logic S4m. The expansion rules in the tableau algorithm ΛS4 are designed to syntactically incorporate the epistemic properties. Blocking is corpo-rated into the tableau expansion rules to ensure termination. We also provide a PSpace implementation for ΛS4. In light of the fact that the satisfiability problem for ALCKm with general TBox and no epistemic properties (i.e., KALC) is NEXPTIME-complete, we conclude that both ALCKm and ALCS4m offer computationally manageable and practically useful fragments of KALC.

The workshop continues the long-standing tradition of international workshops devoted to discussing developments and applications of knowledge representation formalisms and systems based on Description Logics. The list of the International Workshops on Description Logics can be found at http://dl.kr.org.

The workshop continues the long-standing tradition of international workshops devoted to discussing developments and applications of knowledge representation formalisms and systems based on Description Logics. The list of the International Workshops on Description Logics can be found at http://dl.kr.org.

Research on multimedia information retrieval (MIR) has witnessed a booming interest during the last five years or so. A prominent feature of this research trend is its simultaneous but independent materialization within several fields of computer science. The resulting richness of paradigms, methods and systems that has occurred as a result may, on the long run, result in a fragmentation of efforts prone to slow down progress.

This paper presents a three-step approach to enhance interoperability between heterogeneous semantic resources. Firstly, we construct homogeneous representations of these resources in a pivot format, namely OWL DL, with respect to the semantics expressed by the original representation languages. Secondly, mappings are established between concepts of these standardised resources and stored in a so-called articulation ontology. Thirdly, an approach for ranking those mappings
is suggested in order to best fit users’ needs. This approach is currently being implemented in the Semantic Resources “Interoperabilisation” and Linking System (SRILS). The mapping results as well as the work to be done are discussed.

Abstract. One of the main concerns of constructive semantics is to provide a computational interpretation for the proofs of a given logic. In this paper we introduce a constructive semantics for the basic description logic ALC in the spirit of the BHK interpretation. We prove that such a semantics provides an interpretation of ALC formulas consistent with the classical one and we show how, according to such a semantics, proofs of a suitable natural deduction calculus for ALC support a proofs-asprograms paradigm.

In recent years, there has been a growing interest in the application of foundational ontologies, i.e., formal ontological theories in the philosophical sense, to provide a theoretically sound foundation for improving the theory and practice of conceptual modeling and knowledge representation. This paper addresses one particular foundational theory of events termed UFO-B, which has been successfully employed as a reference model for addressing problems from complex media management, enterprise architecture, software engineering, and modeling of events in petroleum exploration. Despite its success, there is still no formalization of UFO-B in a decidable knowledge representation language that could support reasoning about complex events and event relations. We address this gap by proposing a number of alternative translations from UFO-B's original axiomatization (in first-order logic and in the Alloy formal language) to the description logic SROIQ, which is the formal underpinning of OWL 2 DL. Additionally, to support practical applications, we translated these SROIQ theories to OWL 2 DL TBoxes, which were validated by showing that all the intended models of UFO-B (the logical models of the UFO-B specification in Alloy) that we generated are consistent with these UFO-B TBoxes. In a sense, the specification in Alloy implements the specification in first-order logic, while the OWL 2 TBoxes implement the SROIQ specifications. Incidentally, the methodology that we designed for the translation from UFO-B's original axiomatization in FOL and Alloy to SROIQ came to be a key contribution of this work by providing us evidence of the inadequacy of DLs for the specification of comprehensive foundational ontologies.

Istraživanja koja se danas javljaju na području vezanom uz prikazivanje znanja i zaključivanju temeljem tog znanja obično su fokusirana na metode koje pružaju visoku razinu opisa svijeta temeljem kojih se može učinkovito izgraditi različiti inteligentni sustavi. Glavna karakteristika takvih inteligentnih sustava je sposobnost pronalaženja implicitne posljedice onih eksplicitnih znanja. Dakle, cilj takve inteligentne podrške je obrada podataka i informacija te najvažnije pronalaženje i obrada onih podataka i informacija koje nisu eksplicitno definirane u sustavu. Takvi sustavi su poznatiji kao sustavi temeljeni na znanju. Znanje koje se nalazilo u takvim sustavima prikazivalo se u početku preko semantičkih mreža. Daljnjim istraživanjima na tom području shvatilo se da se takve mreže mogu prikazati temeljem semantike koja se oslanja na logiku prvog reda iz čega su zapravo nastale deskriptivne logike. Deskriptivne logike kao takve se danas koriste kao formalni jezik za predstavljanje znanja, a danas ih najčešće možemo susresti u raznim područjima koje zahtijevaju opis znanja na jedan strukturni način (Semantički Web, ontologije i slično).  Uvodim djelom o deskriptivnim logikama može se vidjeti da posjeduju određenu povijest i način razvoja, ali i samu primjenu u različitim područjima. Stoga će se ovaj rad bazirati i pokušati nadalje opširno objasniti deskriptivne logike.

Each paper submitted to DL'04 was reviewed by at least two members of the program committee, or by additional reviewers recruited by the PC members. Due to the success of the poster session from the previous DL workshop, it was decided to schedule a poster session together with a set of system demonstrations that were often motivated by the advent of the semantic web.