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The similarity measure based on fuzzy bisimulation has the Hennessy-Milner property as a strong logical foundation. It is useful for classification and clustering. In this work, we design an efficient algorithm with the complexity O ((m log ⁡ l + n) log ⁡ n) for computing the fuzzy partition corresponding to the greatest fuzzy auto-bisimulation of a finite fuzzy labeled graph G under the Gödel semantics, where n , m and l are the number of vertices, the number of non-zero edges and the number of different fuzzy degrees of edges of G , respectively. Our notion of fuzzy partition is novel, defined for finite sets with respect to the Gödel t-norm, with the aim to facilitate the computation of the greatest fuzzy auto-bisimulation. By using that algorithm, we also provide an algorithm with the complexity O (m ⋅ log ⁡ l ⋅ log ⁡ n + n 2) for computing the greatest fuzzy bisimulation between two finite fuzzy labeled graphs under the Gödel semantics. This latter algorithm is better (has a lower complexity order) than the previously known algorithms for the considered problem. Our algorithms can be restated for other fuzzy graph-based structures such as fuzzy automata, fuzzy labeled transition systems, fuzzy Kripke models, fuzzy social networks and fuzzy interpretations in fuzzy description logics. [ABSTRACT FROM AUTHOR]

We present an efficient algorithm for computing the partition corresponding to the greatest crisp bisimulation of a given finite fuzzy labeled graph. Its complexity is of order O ((m log ⁡ l + n) log ⁡ n) , where n , m and l are the number of vertices, the number of nonzero edges and the number of different fuzzy degrees of edges of the input graph, respectively. We also study a similar problem for the setting with counting successors, which corresponds to the case with qualified number restrictions in description logics and graded modalities in modal logics. In particular, we provide an efficient algorithm with the complexity O ((m log ⁡ m + n) log ⁡ n) for the considered problem in that setting. [ABSTRACT FROM AUTHOR]

Abstract We introduce a nonmonotonic procedure for preferential Description Logics in order to reason about typicality by taking probabilities of exceptions into account. We consider an extension, called ALC + T R P , of the logic of typicality ALC + T R by inclusions of the form T (C) ⊑ p D with probability p , whose intuitive meaning is that "all the typical C s are D s, and the probability that a C is not a D is 1 − p ". We consider a notion of extension of an ABox containing only some typicality assertions, then we equip each extension with a probability. We then restrict entailment of a query F to those extensions whose probabilities belong to a given and fixed range. We propose a decision procedure for reasoning in ALC + T R P and we exploit it to show that entailment is ExpTime -complete as for the underlying ALC. [ABSTRACT FROM AUTHOR]

In this paper we investigate the relationships between a multipreferential semantics for defeasible reasoning in knowledge representation and a multilayer neural network model. Weighted knowledge bases for a simple description logic with typicality are considered under a (many-valued) "concept-wise" multipreference semantics. The semantics is used to provide a preferential interpretation of MultiLayer Perceptrons (MLPs). A model checking and an entailment based approach are exploited in the verification of conditional properties of MLPs. [ABSTRACT FROM AUTHOR]

Abstract Defeasible Description Logics (DDLs) extend Description Logics with defeasible concept inclusions. Reasoning in DDLs often employs rational closure according to the (propositional) KLM postulates. A well-known approach to lift this closure to DDLs is by so-called materialisation. Previously investigated algorithms for materialisation-based reasoning employ reductions to classical reasoning using all Boolean connectors. As a first result in this paper, we present a materialisation-based algorithm for the sub-Boolean DDL Image 2 , using a reduction to reasoning in classical Image 2 , rendering materialisation-based defeasible reasoning tractable. The main contribution of this article is a kind of canonical model construction, which can be used to decide defeasible subsumption and instance queries in Image 2 under rational and the stronger relevant entailment. Our so-called typicality models can reproduce the entailments obtained from materialisation-based rational and relevant closure and, more importantly, obtain stronger versions of rational and relevant entailment. These do not suffer from neglecting defeasible information for concepts appearing nested inside quantifications, which all materialisation-based approaches do. We also show the computational complexity of defeasible subsumption and instance checking in our stronger rational and relevant semantics. [ABSTRACT FROM AUTHOR]

Abstract The aim of this paper is to introduce a new framework for defining abductive reasoning operators based on a notion of retraction in arbitrary logics defined as satisfaction systems. We show how this framework leads to the design of explanatory relations satisfying properties of abductive reasoning, and discuss its application to several logics. This extends previous work on propositional logics where retraction was defined as a morphological erosion. Here weaker properties are required for retraction, leading to a larger set of suitable operators for abduction for different logics. Highlights • New framework for defining abductive reasoning operators in arbitrary logics defined as satisfaction systems. • Explanatory relations from generic notions of cutting and retraction. • Proof of rationality postulates. • Instantiation in various logics, with concrete examples of explanatory relations. [ABSTRACT FROM AUTHOR]

In the field of non-monotonic logics, the notion of Rational Closure (RC) is acknowledged as a notable approach. In recent years, RC has gained popularity in the context of Description Logics (DLs), the logic underpinning the standard semantic Web Ontology Language OWL 2, whose main ingredients are classes, the relationship among classes and roles, which are used to describe the properties of classes. In this work, we show instead how to integrate RC within the triple language RDFS (Resource Description Framework Schema), which together with OWL 2 is a major standard semantic web ontology language. To do so, we start from ρ df, a minimal, but significant RDFS fragment that covers the essential features of RDFS, and then extend it to ρ df ⊥ , allowing to state that two entities are incompatible/disjoint with each other. Eventually, we propose defeasible ρ df ⊥ via a typical RC construction allowing to state default class/property inclusions. Furthermore, to overcome the main weaknesses of RC in our context, i.e. , the "drowning problem" (viz. the "inheritance blocking problem"), we further extend our construction by leveraging Defeasible Inheritance Networks (DIN) defining a new non-monotonic inference relation that combines the advantages of both (RC and DIN). To the best of our knowledge this is the first time of such an attempt. In summary, the main features of our approach are: (i) the defeasible ρ df ⊥ we propose here remains syntactically a triple language by extending it with new predicate symbols with specific semantics; (ii) the logic is defined in such a way that any RDFS reasoner/store may handle the new predicates as ordinary terms if it does not want to take account of the extra non-monotonic capabilities; (iii) the defeasible entailment decision procedure is built on top of the ρ df ⊥ entailment decision procedure, which in turn is an extension of the one for ρ df via some additional inference rules favouring a potential implementation; (iv) the computational complexity of deciding entailment in ρ df and ρ df ⊥ are the same; and (v) defeasible entailment can be decided via a polynomial number of calls to an oracle deciding ground triple entailment in ρ df ⊥ and, in particular, deciding defeasible entailment can be done in polynomial time. [ABSTRACT FROM AUTHOR]

Dynamic monitoring and management of traffic is a significant challenge which requires a mobile surveillance system which is becoming feasible with the evolution of 5G and related technologies. With the advent of 5G, huge amount of data can be transferred over long distance. Furthermore, the evolution of Multi-access Edge Computing (MEC) offers the processing near the edge, resulting in quick response which can cater to mobile surveillance. The mobile surveillance can be performed through a vehicle (Unmanned Aerial Vehicle (UAV)/mobile vehicle) which collects the multi-modal data and sends to nearest edge server over the 5G network. The server sends response quickly to the control center from where the appropriate action can be taken to mitigate its effect on the individuals in real-time. Furthermore, the analysis of multi-modal data captured by surveillance systems must be integrated and efficiently represented. Therefore, in this work, an ontology-based approach is proposed by integrating unstructured video data and structured sensor data for detecting and identifying the complex event of illegal parking. Identifying illegally parked vehicles needs dynamic and strict monitoring; which require the deployment of surveillance systems across the entire city. However, installing a video camera at each place is not feasible. Therefore, the surveillance thorough mobile vehicle is presented to identify illegal parked vehicle for traffic management over the 5G network. In addition, an ontology is developed to represent and reason over the roadside video data while integrating it with sensor data to form a knowledge graph. The knowledge graph retrieves semantic information about the events using SPARQL queries and Description Logics (DL) queries. Thus, a complete video is not required and the extracted information is stored in Resource Description Framework (RDF) format to reduce space requirement significantly. The approach is evaluated by recognizing the complex events of detecting illegally parked vehicles on a real-time dataset recorded using the experimental setup. Furthermore, the framework represents the surveillance video data of parked vehicles captured using the camera installed in a mobile vehicle to cover the road, including the vehicle information location, position, time, etc., as a knowledge graph that can be used later for further analysis. • An ontology for representing and storing roadside surveillance data as knowledge graphs. • A data integration approach that integrates sensory data with video data to perform complex reasoning. • The information retrieval is performed using DL and SPARQL queries. • A novel ontology-based algorithm to identify illegally parked vehicles. • A real-time surveillance dataset containing illegally parked vehicles. [ABSTRACT FROM AUTHOR]

In this paper we study the relationships between a family of ALC -like fuzzy description logics (FDLs) defined over left-continuous t-norms and some many-valued multi-modal logics (MMLs). We analyze these relationships in both directions, that is, how to merge FDLs into MMLs and vice-versa. The analysis starts from the relationships between the languages to reach systematically the deeper level of reasoning tasks. At this level we are able to truly investigate both formalisms from each other point of view. Finally, the results concerning translations between reasoning tasks are applied in order to get decidability and complexity bounds. [ABSTRACT FROM AUTHOR]

In this paper, we present a distance-based framework for DL-Lite based on the notion of features. Within this framework, we propose a distance-based paraconsistent semantics for DL-Lite where meaningful conclusions can be rationally drawn even from an inconsistent knowledge base and we develop a distance-based inconsistency measurement for DL-Lite to provide more informative metrics which can tell the differences between axioms causing inconsistency and among inconsistent knowledge. Furthermore, we investigate several important logical properties (e.g., consistency preservation, closure consistency, splitting property etc.) of the entailment relation based on the new semantics and show its advantages in non-monotonic reasoning for DL-Lite. Finally, we show that our two distance-based inconsistency measures are basic inconsistency measures where some good properties hold such as Free Axiom Independence and Dominance of inconsistency etc. [ABSTRACT FROM AUTHOR]

Fuzzy description logics (FDLs) are knowledge representation formalisms capable of dealing with imprecise knowledge by allowing intermediate membership degrees in the interpretation of concepts and roles. One option for dealing with these intermediate degrees is to use the so-called Gödel semantics, under which conjunction is interpreted by the minimum of the degrees of the conjuncts. Despite its apparent simplicity, developing reasoning techniques for expressive FDLs under this semantics is a hard task. In this paper, we introduce two new algorithms for reasoning in very expressive FDLs under Gödel semantics. They combine the ideas of a previous automata-based algorithm for Gödel FDLs with the known crispification and tableau approaches for FDL reasoning. The results are the two first practical algorithms capable of reasoning in infinitely valued FDLs supporting general concept inclusions. [ABSTRACT FROM AUTHOR]

Keywords: Cancer; Health and Medicine; Information Technology; Information and Data Validation; Oncology; Pediatrics EN Cancer Health and Medicine Information Technology Information and Data Validation Oncology Pediatrics 247 247 1 07/31/23 20230801 NES 230801 2023 AUG 1 (NewsRx) -- By a News Reporter-Staff News Editor at Clinical Oncology Week -- New study results on cancer have been published. Cancer, Health and Medicine, Information Technology, Information and Data Validation, Oncology, Pediatrics. [Extracted from the article]

System-of-systems (SoS) engineering involves a complex process of refining high-level SoS requirements into more detailed systems requirements and assessing the extent to which the performances of to-be systems may possibly satisfy SoS capability objectives. The key issue is how to model such requirements to automate the process of analysis and assessment. This paper suggests a meta-model that defines both functional and nonfunctional features of SoS requirements for command and control, communication, computer, intelligence, surveillance reconnaissance (C4ISR) systems. A domain-specific modeling language is defined by extending unified modeling language (UML) constructed of class and association with fuzzy theory in order to model the fuzzy concepts of performance requirements. An efficiency evaluation function is introduced, based on Bezier curves, to predict the effectiveness of systems. An algorithm is presented to transform domain models in fuzzy UML into a requirements ontology in description logic (DL) so that requirements verification can be automated with a popular DL reasoner such as Pellet. [ABSTRACT FROM AUTHOR]

We study bisimulations for useful description logics. The simplest among the considered logics is ALC reg (a variant of PDL). The others extend that logic with the features: inverse roles, nominals, qualified number restrictions, the universal role, and/or the concept constructor for expressing the local reflexivity of a role. They also allow role axioms. Our contributions are as follows. We propose to treat named individuals as initial states and give an appropriate bisimulation condition for that. We also give bisimulation conditions for the universal role and the concept constructor ∃ r . Self . We prove that all of the bisimulation conditions for the features can be combined together to guarantee invariance of concepts and the Hennessy-Milner property for the whole class of studied description logics. We address and give results on invariance or preservation of ABoxes, RBoxes and knowledge bases in description logics. Independently from Lutz et al. [26,27] we also give results on invariance of TBoxes. We introduce a new notion called QS-interpretation, which is needed for dealing with minimizing interpretations in description logics with qualified number restrictions and/or the concept constructor ∃ r . Self . We formulate and prove results on minimality of quotient interpretations w.r.t. the largest auto-bisimulations. We adapt Hopcroft’s automaton minimization algorithm to give an efficient algorithm for computing the partition corresponding to the largest auto-bisimulation of a finite interpretation in any description logic of the considered family. Using the invariance results we compare the expressiveness of the considered description logics w.r.t. concepts, TBoxes and ABoxes. Our results about separating the expressiveness of description logics are naturally extended to the case when instead of ALC reg we have any sublogic of ALC reg that extends ALC . [ABSTRACT FROM AUTHOR]

Description Logics (DLs) are a well-established family of knowledge representation formalisms. One of its members, the DL ELOR has been successfully used for representing knowledge from the bio-medical sciences, and is the basis for the OWL 2 EL profile of the standard ontology language for the Semantic Web. Reasoning in this DL can be performed in polynomial time through a completion-based algorithm. In this paper we study the logic Prob- ELOR , that extends ELOR with subjective probabilities, and present a completion-based algorithm for polynomial time reasoning in a restricted version, Prob- ELOR c 01 , of Prob- ELOR . We extend this algorithm to computation algorithms for approximations of (i) the most specific concept, which generalizes a given individual into a concept description, and (ii) the least common subsumer, which generalizes several concept descriptions into one. Thus, we also obtain methods for these inferences for the OWL 2 EL profile. These two generalization inferences are fundamental for building ontologies automatically from examples. The feasibility of our approach is demonstrated empirically by our prototype system Gel . [ABSTRACT FROM AUTHOR]

This paper deals with finitely-valued fuzzy description languages from a logical point of view. From recent results in Mathematical Fuzzy Logic and following [44] , we develop a Fuzzy Description Logic based on the fuzzy logic of a finite BL -chain. The constructors of the languages presented in this paper correspond to the connectives of that logic (containing an involutive negation, Monteiro–Baaz delta and hedges). The paper addresses the hierarchy of fuzzy attributive languages; knowledge bases and their reductions; reasoning tasks; and complexity. Our results regarding decidability together with a summary of the known results related to computational complexity are of particular interest. In Appendix B we also provide axiomatizations for expansions of the logic of a finite BL -chain considered in the paper. [ABSTRACT FROM AUTHOR]

Abstract: The Web Ontology Language (OWL) is a family of description logic based ontology languages for the Semantic Web and gives well defined meaning to web accessible information and services. The study of inconsistency-tolerant reasoning with description logic knowledge bases is especially important for the Semantic Web since knowledge is not always perfect within it. An important challenge is strengthening the inference power of inconsistency-tolerant reasoning because it is normally impossible for paraconsistent logics to obey all important properties of inference together. This paper presents a non-classical DL called quasi-classical description logic (QCDL) to tolerate inconsistency in OWL DL which is a most important sublanguage of OWL supporting those users who want the maximum expressiveness while retaining computational completeness (i.e., all conclusions are guaranteed to be computable) and decidability (i.e., all computations terminate in finite time). Instead of blocking those inference rules, we validate them conditionally and partially, under which more useful information can still be inferred when inconsistency occurs. This new non-classical DL possesses several important properties as well as its paraconsistency in DL, but it does not bring any extra complexity in worst case. Finally, a transformation-based algorithm is proposed to reduce reasoning problems in QCDL to those in DL so that existing OWL DL reasoners can be used to implement inconsistency-tolerant reasoning. Based on this algorithm, a prototype OWL DL paraconsistent reasoner called PROSE is implemented. Preliminary experiments show that PROSE produces more intuitive results for inconsistent knowledge bases than other systems in general. [Copyright &y& Elsevier]

Abstract: Recently there have been some unexpected results concerning Fuzzy Description Logics (FDLs) with General Concept Inclusions (GCIs). They show that, unlike the classical case, the DL with GCIs does not have the finite model property under Łukasiewicz Logic or Product Logic, the proposed reasoning algorithms are neither correct nor complete and, specifically, knowledge base satisfiability is an undecidable problem for Product Logic. In this work, we show that knowledge base satisfiability is also an undecidable problem for Łukasiewicz Logic. We additionally provide a decision algorithm for acyclic knowledge bases under Łukasiewicz Logic via a Mixed Integer Linear Programming (MILP) based procedure (note, however, that the decidability of this problem is already known). While similar MILP based algorithms have been proposed in the literature for acyclic knowledge bases under Łukasiewicz Logic, none of them exhibit formal proofs of their correctness and completeness, which is the additional contribution here. [Copyright &y& Elsevier]

Abstract: Description logics (DLs) are a family of logics for representing structured knowledge which have proved to be very useful as ontology languages. Classical DLs are not suitable to represent vague pieces of information. The attempts to achieve a solution have led to the birth of fuzzy DLs and rough DLs. In this work, we provide a simple solution to join these two formalisms and define a fuzzy rough DL. This logic is more general than other related approaches, including tight and loose fuzzy rough approximations and being independent of the fuzzy logic operators considered. We show the usefulness of our approach by presenting some uses case, and we also describe how to extend two reasoning algorithms for fuzzy DLs, which are implemented in the fuzzy DL reasoners fuzzyDL and DeLorean. [Copyright &y& Elsevier]

Neoliberalism is often addressed by commentators and critics as a set of ideas or a doctrine. This article considers neoliberalism as a set of financial practices and exchanges - as about money and profit - and goes on to suggest that as practitioners, researchers, activists we need to understand and engage with that logic and its mechanisms. Examples are given of the role of money in all aspects of education policy and education reform. [ABSTRACT FROM AUTHOR]

Abstract: The need to deal with vague information in Semantic Web languages is rising in importance and, thus, calls for a standard way to represent such information. We may address this issue by either extending current Semantic Web languages to cope with vagueness, or by providing a procedure to represent such information within current standard languages and tools. In this work, we follow the latter approach, by identifying the syntactic differences that a fuzzy ontology language has to cope with, and by proposing a concrete methodology to represent fuzzy ontologies using OWL 2 annotation properties. We also report on some prototypical implementations: a plug-in to edit fuzzy ontologies using OWL 2 annotations and some parsers that translate fuzzy ontologies represented using our methodology into the languages supported by some reasoners. [Copyright &y& Elsevier]

Abstract: Fuzzy Description Logics are a formalism for the representation of structured knowledge affected by imprecision or vagueness. They have become popular as a language for fuzzy ontology representation. To date, most of the work in this direction has focused on the so-called Zadeh family of fuzzy operators (or fuzzy logic), which has several limitations. In this paper, we generalize existing proposals and show how to reason with a fuzzy extension of the logic , the logic behind the language OWL 2, under finitely many-valued Łukasiewicz fuzzy logic. We show for the first time that it is decidable over a finite set of truth values by presenting a reasoning preserving procedure to obtain a non-fuzzy representation for the logic. This reduction makes it possible to reuse current representation languages as well as currently available reasoners for ontologies. [ABSTRACT FROM AUTHOR]

The Semantic Web is an extension of the current web, where information would have precisely defined meaning, based on knowledge representation languages. The current W3C standard for representing knowledge is the Web Ontology Language (OWL). OWL is based on Description Logics which is a popular knowledge representation formalism. Although, DLs are quire expressive they feature limitations with respect to what can be said about vague knowledge, which appears in several applications. Consequently, fuzzy extensions to OWL and DLs have gained considerable attention. In the current paper we study fuzzy extensions of the Semantic Web language OWL. First, we present the (abstract) syntax and semantics of a rather elementary fuzzy extension of OWL creating fuzzy OWL (f-OWL). More importantly we use this extension to provide an investigation on the semantics of several f-OWL axioms and more precisely for those which, in classical DLs, can be expressed in different but equivalent ways. Moreover, we present a translation method which reduces inference problems of f-OWL into inference problems of expressive fuzzy Description Logics, in order to provide reasoning support through fuzzy DLs. Finally, we present two further fuzzy extensions of OWL based on fuzzy subsumption and fuzzy nominals. [Copyright &y& Elsevier]

Abstract: 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. Hájek proposed to deal with FDLs taking as basis t-norm based fuzzy logics with the aim of enriching the expressive possibilities in FDLs and to capitalize on recent developments in the field of Mathematical Fuzzy Logic. From this perspective we define a family of description languages, denoted by , which includes truth constants for representing truth degrees. Having truth constants in the language allows us to define the axioms of the knowledge bases as sentences of a predicate language in much the same way as in classical DLs. On the other hand, taking advantage of the expressive power provided by these truth constants, we define a graded notion of satisfiability, validity and subsumption of DL concepts as the satisfiability, validity and subsumption of evaluated formulas. In the last section we summarize some results concerning fuzzy logics associated with these new description languages, we analyze aspects relative to general and canonical semantics, and we prove some results relative to canonical standard completeness for some FDLs considered in the paper. [Copyright &y& Elsevier]

Abstract: Description logics (DLs) play an important role in the Semantic Web as the foundation of ontology language OWL DL. On the other hand, uncertainty is a form of deficiency or imperfection commonly found in real-world information/data. In this paper, we present a framework for knowledge bases with uncertainty expressed in the description logic , which is a propositionally complete representation language providing conjunction, disjunction, existential and universal quantifications, and full negation. The proposed framework is equipped with a constraint-based reasoning procedure that derives a collection of assertions as well as a set of linear/nonlinear constraints that encode the semantics of the uncertainty knowledge base. The interesting feature of our approach is that, by simply tuning the combination functions that generate the constraints, different notions of uncertainty can be modeled and reasoned with, using a single reasoning procedure. We establish soundness, completeness, and termination of the reasoning procedure. Detailed explanations and examples are included to describe the proposed completion rules. [Copyright &y& Elsevier]

Abstract: It is generally accepted that the management of imprecision and vagueness will yield more intelligent and realistic knowledge-based applications. Description Logics (DLs) are suitable, well-known logics for managing structured knowledge that have gained considerable attention the last decade. The current research progress and the existing problems of uncertain or imprecise knowledge representation and reasoning in DLs are analyzed in this paper. An integration between the theories of intuitionistic fuzzy DLs and rough DLs has been attempted by providing intuitionistic fuzzy rough DLs based on intuitionistic fuzzy rough set theory. The syntax, semantics and properties of intuitionistic fuzzy rough DLs are given. It is proved that the satisfiability, subsumption, entailment and ABox consistency reasoning in intuitionistic fuzzy rough DLs may be reduced to the corresponding satisfiability, subsumption, entailment and ABox consistency reasoning in fuzzy DL over complete lattice, respectively. [Copyright &y& Elsevier]

Abstract: The current research progress and the existing problems of uncertain or imprecise knowledge representation and reasoning in description logics are analyzed in this paper. Approximate concepts are introduced to description logics based on rough set theory, and a kind of new rough description logic (rough description logic based on approximate concepts) is proposed based on approximate concepts. The syntax, semantics and properties of the are given. It is proved that the approximate concept satisfiability (definitely satisfiability and possibly satisfiability) reasoning problem and approximate concepts rough subsumption reasoning problem w.r.t. rough TBox in may be reduced to the concept satisfiability reasoning problem in (almost) standard ALC (the description logic that provides the Boolean concept constructors plus the existential and universal restriction constructors). The works of this paper provide logic foundations for approximate ontologies and theoretical foundations for reasoning algorithms of more expressive rough description logics including approximate concepts, number restrictions, nominals, inverse roles and role hierarchies. [Copyright &y& Elsevier]

The purpose of this paper is to propose an expansion-contraction framework for linear constant descriptor systems within the inclusion principle for dynamic systems. Our primary objective is to provide an explicit characterization of the expansion process whereby a given descriptor system is expanded into the larger space where all its solutions are reproducible by the expanded descriptor system if appropriate initial conditions are selected. When a control law is formulated in the expanded space, the proposed characterizations provide contractibility conditions for implementation of the control law in the original system. A full freedom is provided for selecting appropriate matrices in the proposed expansion-contraction control scheme. In particular, the derived theoretical framework serves as a flexible environment for expansion-contraction control design of descriptor systems under overlapping information structure constraints. [ABSTRACT FROM AUTHOR]

Abstract: Towards uncertainty reasoning in the Rules, Logic, and Proof layers of the Semantic Web, we present a novel approach to probabilistic description logic programs, which combine probabilistic logic programs, probabilistic default theories, and the description logics behind OWL Lite and OWL DL. The approach is based on new notions of entailment for reasoning with conditional constraints, which realize the principle of inheritance with overriding for both classical and purely probabilistic knowledge. They are obtained by generalizing previous formalisms for probabilistic default reasoning with conditional constraints. In addition to dealing with probabilistic knowledge, the new notions of entailment thus also allow for handling default knowledge. We analyze the semantic properties of the new entailment relations. We also present algorithms for solving the main computational problems related to probabilistic description logic programs under inheritance with overriding. [Copyright &y& Elsevier]

EKOSS, which stands for Expert Knowledge Ontology-based Semantic Search, has been developed for the sharing of scientific knowledge using Semantic Web technologies. The EKOSS website provides a publication environment for scientific researchers where they can create by themselves computer-interpretable semantic descriptions of their knowledge resources, such as papers and databases, using ontologies based on description logics and publish those descriptions together with their knowledge resources. At the same time, through the use of inference based on description logics, a person using the EKOSS semantic search system to look for scientific knowledge can more accurately find the knowledge that best matches his or her knowledge requirements. Because the EKOSS approach makes it possible for computers to match knowledge resources and requirements semantically, we hope that the EKOSS system will support not only sharing of scientific knowledge between researchers, but also more effective knowledge transfer to other members of society. [ABSTRACT FROM AUTHOR]

The article discusses the role of ontologies and description logics in the construction of e-learning systems. Ontologies are graphs or large concept maps consisting of nodes that represent a single concept and links between pairs of nodes that express relationships between them. Classes and instances are called the building blocks of ontologies. Instances represent things in the world while classes represent categories of instances that are similar in some way. An instance can be a member of one or more classes. Ontology is useful for systematically storing and retrieving concepts used in e-learning, and also beneficial to explore the relationship between the cognitive basis of ontologies and the cognitive processes involved in learning. A database management system called Lyra has been created using a description logic as the language for defining data objects and includes a number of Web-based visual design tools for browsing, creating, and editing content objects used in e-learning. While object-based database systems offer storage and retrieval mechanisms that can exploit more of the semantic structure of the databases, they utilize programming languages as their model for specifying objects.

The article focuses on the English language used to describe men and women in sports through the use collection of data called the Cambridge English Corpus (CEC) and the Sports Corpus. Among the words used for male Olympians are mastermind, dominate, battle, beat, and win, whereas female describes as compete, participate, and strive.

The article focuses on the significance of imagination for the blinded individuals and how much the unsighted make use of the intense descriptions afforded by the sighted world. It notes the need of these individuals for help by educating the people around them. It points out that this will make people realize that there is no difference between the visually impaired and those who are not.

The article focuses on the definition of various terms and abbreviations that are commonly used for the description of ruling condition. The term Revoked is applied to the condition where the position of the previously published ruling is not correct and the correct position is applicable to a new ruling. The term Modified dictates the correction in the position of the previous published ruling. Obsoleted describes that previously published ruling is not applicable due to the changes in laws.

A correction to the article about an AO-40 satellite dish featured on the cover of the August 2006 issue is presented.

An excerpt from a description in an Italian guidebook of La Villa Adriana in Tivoli, New York about the Mediterranean description is presented.