Alessandro Artale

Alessandro Artale
Free University of Bozen-Bolzano | Unibolzano · Faculty of Computer Science

About

118
Publications
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2,670
Citations
Citations since 2017
17 Research Items
702 Citations
2017201820192020202120222023020406080100120140
2017201820192020202120222023020406080100120140
2017201820192020202120222023020406080100120140
2017201820192020202120222023020406080100120140

Publications

Publications (118)
Article
Aiming at ontology-based data access to temporal data, we design two-dimensional temporal ontology and query languages by combining logics from the (extended) DL-Lite family with linear temporal logic LTL over discrete time (Z,<). Our main concern is first-order rewritability of ontology-mediated queries (OMQs) that consist of a 2D ontology and a p...
Preprint
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Linear Temporal Logic (LTL) is the de-facto standard temporal logic for system specification, whose foundational properties have been studied for over five decades. Safety and cosafety properties define notable fragments of LTL, where a prefix of a trace suffices to establish whether a formula is true or not over that trace. In this paper, we study...
Conference Paper
In recent years, spiking neural networks (SNNs) have received extensive attention in brain-inspired intelligence due to their rich spatially-temporal dynamics, various encoding methods, and event-driven characteristics that naturally fit the neuromorphic hardware. With the development of SNNs, brain-inspired intelligence, an emerging research field...
Preprint
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Formalisms based on temporal logics interpreted over finite strict linear orders, known in the literature as finite traces, have been used for temporal specification in automated planning, process modelling, (runtime) verification and synthesis of programs, as well as in knowledge representation and reasoning. In this paper, we focus on first-order...
Preprint
Aiming at ontology-based data access to temporal data, we design two-dimensional temporal ontology and query languages by combining logics from the (extended) DL-Lite family with linear temporal logic LTL over discrete time (Z,<). Our main concern is first-order rewritability of ontology-mediated queries (OMQs) that consist of a 2D ontology and a p...
Conference Paper
Definite descriptions are phrases of the form ‘the x such that φ’, used to refer to single entities in a context. They are often more meaningful to users than individual names alone, in particular when modelling or querying data over ontologies. We investigate free description logics with both individual names and definite descriptions as terms of...
Preprint
Full-text available
Definite descriptions are phrases of the form 'the $x$ such that $\varphi$', used to refer to single entities in a context. They are often more meaningful to users than individual names alone, in particular when modelling or querying data over ontologies. We investigate free description logics with both individual names and definite descriptions as...
Article
The Craig interpolation property (CIP) states that an interpolant for an implication exists iff it is valid. The projective Beth definability property (PBDP) states that an explicit definition exists iff a formula stating implicit definability is valid. Thus, the CIP and PBDP transform potentially hard existence problems into deduction problems in...
Article
We investigate ontology-based data access to temporal data. We consider temporal ontologies given in linear temporal logic LTL interpreted over discrete time (Z,<). Queries are given in LTL or MFO(<), monadic first-order logic with a built-in linear order. Our concern is first-order rewritability of ontology-mediated queries (OMQs) consisting of a...
Preprint
Full-text available
This paper investigates the feasibility of automated reasoning over temporal DL-Lite (TDL-Lite) knowledge bases (KBs). We test the usage of off-the-shelf LTL reasoners to check satisfiability of TDL-Lite KBs. In particular, we test the robustness and the scalability of reasoners when dealing with TDL-Lite TBoxes paired with a temporal ABox. We cond...
Preprint
The Craig interpolation property (CIP) states that an interpolant for an implication exists iff it is valid. The Beth definability property (BDP) states that an explicit definition exists iff a formula stating implicit definability is valid. Thus, they transform potentially hard existence problems into deduction problems in the underlying logic. De...
Preprint
We investigate ontology-based data access to temporal data. We consider temporal ontologies given in linear temporal logic LTL interpreted over discrete time (Z,<). Queries are given in LTL or MFO(<), monadic first-order logic with a built-in linear order. Our concern is first-order rewritability of ontology-mediated queries (OMQs) consisting of a...
Conference Paper
Linear temporal logic over finite traces is used as a formalism for temporal specification in automated planning, process modelling and (runtime) verification. In this paper, we investigate first-order temporal logic over finite traces, lifting some known results to a more expressive setting. Satisfiability in the two-variable monodic fragment is s...
Chapter
Existing process modeling notations ranging from Petri nets to BPMN have difficulties capturing the data manipulated by processes. Process models often focus on the control flow, lacking an explicit, conceptually well-founded integration with real data models, such as ER diagrams or UML class diagrams. To overcome this limitation, Object-Centric Be...
Conference Paper
Full-text available
We introduce \(\mathcal{DLR}^+\), an extension of the n-ary propositionally closed description logic \(\mathcal{DLR}\) to deal with attribute-labelled tuples (generalising the positional notation), projections of relations, and global and local objectification of relations, able to express inclusion, functional, key, and external uniqueness depende...
Article
We introduce $\mathcal{DLR}^+$, an extension of the n-ary propositionally closed description logic $\mathcal{DLR}$ to deal with attribute-labelled tuples (generalising the positional notation), projections of relations, and global and local objectification of relations, able to express inclusion, functional, key, and external uniqueness dependencie...
Chapter
We discuss the use of various temporal knowledge representation formalisms for ontology-mediated query answering over temporal data. In particular, we analyse ontology and query languages based on the linear temporal logic LTL, the multi-dimensional Halpern-Shoham interval temporal logic HSn, as well as the metric temporal logic MTL. Our main focus...
Article
We introduce an extension of the n-ary description logic DLR to deal with attribute-labelled tuples (generalising the positional notation), with arbitrary projections of relations (inclusion dependencies), generic functional dependencies and with global and local objectification (reifying relations or their projections). We show how a simple syntac...
Article
We design a tractable Horn fragment of the Halpern-Shoham temporal logic and extend it to interval-based temporal description logics, instance checking in which is P-complete for both combined and data complexity.
Chapter
Aiming at ontology-based data access over temporal, in particular streaming data, we design a language of ontology-mediated queries by extending OWL 2 QL and SPARQL with temporal operators, and investigate rewritability of these queries into two-sorted first-order logic with < and PLUS over time.
Chapter
We design a tractable Horn fragment of the Halpern-Shaham temporal logic and extend it to interval-based temporal description logics, instance checking in which is P-complete for both combined and data complexity.
Article
Full-text available
Description logics of the DL-Lite family are widely used in knowledge representation because of their low computational complexity and rather good expressivity sufficient to capture important conceptual modelling constructs and the OWL2 QL profile of the Ontology Web Language (OWL). Recently, various point-based temporal extensions of DL-Lite have...
Chapter
We investigate various types of query rewriting over ontologies given in the standard temporal logic LTL as well as combinations of LTL with DL-Lite logics. In particular, we consider FO(<)-rewritings that can use the temporal precedence relation, FO(<; +)-rewritings that can also employ the arithmetic predicate PLUS, and rewritings to fi�nite auto...
Conference Paper
We investigate the problem of the (re-)identification of new entities emerging from the presence of relationships in a conceptual schema. While the general practice is to reify the relation and thus individuating as many individuals as many tuples in the original relation, we propose here different identification methods based on the possibility of...
Conference Paper
Full-text available
We introduce and investigate a number of fragments of propo- sitional temporal logic LTL over the flow of time (Z, <). The fragments are defined in terms of the available temporal operators and the structure of the clausal normal form of the temporal formulas. We determine the computational complexity of the satisfiability problem for each of the f...
Article
Full-text available
Our aim is to investigate ontology-based data access over temporal data with validity time and ontologies capable of temporal conceptual modelling. To this end, we design a temporal description logic, TQL, that extends the standard ontology language OWL 2 QL, provides basic means for temporal conceptual modelling and ensures first-order rewritabili...
Article
We design a temporal description logic, TQL, that extends the standard ontology language OWL 2QL, provides basic means for temporal conceptual modelling and ensures first-order rewritability of conjunctive queries for suitably defined data instances with validity time.
Article
Full-text available
We design temporal description logics suitable for reasoning about temporal conceptual data models and investigate their computational complexity. Our formalisms are based on DL-Lite logics with three types of concept inclusions (ranging from atomic concept inclusions and disjointness to the full Booleans), as well as cardinality constraints and ro...
Article
Full-text available
UML has become a de facto standard in conceptual model-ing. Class diagrams in UML allow one to model the data in the domain of interest by specifying a set of graphical constraints. However, in most cases one needs to provide the class diagram with additional semantics to completely specify the domain, and this is where OCL comes into play. While r...
Article
We extend the DL-Lite languages by means of attributes and datatypes. Attributes-a notion borrowed from data models-associate concrete values from datatypes to abstract objects and in this way complement roles, which describe relationships between abstract objects. The extended languages remain tractable (with a notable exception) even though they...
Conference Paper
Full-text available
Temporal data models have been used to describe how data can evolve in the context of temporal databases. Both the Extended Entity-Relationship (EER) model and the Unified Modelling Language (UML) have been temporally extended to design temporal databases. To automatically check quality properties of conceptual schemas various encoding to Descripti...
Conference Paper
We describe a mapping of Extended Entity-Relationship schemata to Answer Set Programming that allows us to generate informative example instances of the relational database that is implied by the conceptual schema. Such instances may be submitted to people involved in the requirements phase as a glimpse of what instances are allowed by the E-R sche...
Conference Paper
The DL-Lite family of description logics has recently been proposed and investigated in [5–7] and later extended in [1, 8, 3]. The relevance of the DL-Lite family is witnessed by the fact that it forms the basis of OWL 2 QL, one of the three
Article
To ensure the quality of an information system we must guarantee the correctness of the conceptual schema that represents the knowledge about its domain. The high expressivity of UML schemas annotated with textual OCL constraints enforces the need for automated reasoning techniques. These techniques should be both terminating and complete to be eff...
Conference Paper
Full-text available
Conceptual modelling formalisms such as the Entity-Relationship model (ER) and Unified Modelling Language (UML) have become a de facto standard in database design by providing visual means to describe application domains in a declarative and reusable way. On the other hand, both ER and UML turned out
Conference Paper
Full-text available
We investigate the computational complexity of reasoning over temporal extensions of conceptual data models. The temporal conceptual models we analyse include the standard UML/EER constructs, such as isa between entities and relationships, disjointness and covering, cardinality constraints and their refinements, multiplicity and key constraints; in...
Conference Paper
Full-text available
We design minimal temporal description logics that are capable of expressing various aspects of temporal conceptual data models and investigate their computational complexity. We show that, depending on the required types of temporal and atemporal constraints, the satisfiability problem for temporal knowledge bases in the resulting logics can be NL...
Conference Paper
Full-text available
UML class diagrams (UCDs) are the de-facto standard formalism for the analysis and design of information systems. By adopting formal language techniques to capture constraints expressed by UCDs one can exploit automated reasoning tools to detect relevant properties, such as schema and class satisfiability and subsumption between classes. Among the...
Conference Paper
Representing and reasoning over evolving objects has been investigated widely. Less attention has been devoted to the similar notion of \emph{relation migration}, i.e., how tuples of a relation (ORM facts) can evolve along time. We identify different ways how a relation can change over time and give a logic-based semantics to the notion of rel...
Conference Paper
Full-text available
Relation Based Access Control (RelBAC) is an access control model that places permissions as first class concepts. Under this model, we discuss in this paper how to formalize typical access control policies with Description Logics. Important security properties, i.e., Separation of Duties (SoD) and Chinese Wall are studied and formally represented...
Article
We design minimal temporal description logics that are capa- ble of expressing various aspects of temporal conceptual data models and investigate their computational complexity. We show that, depending on the required types of temporal and atemporal constraints, the satisfiability problem for temporal knowledge bases in the resulting logics can be...
Conference Paper
UML class diagrams (UCDs) are the de-facto standard formalism for the analysis and design of information systems. By adopting formal language techniques to capture constraints expressed by UCDs one can exploit automated reasoning tools to detect relevant properties, such as schema and class satisfiability and subsumption between classes. Among the...
Article
Full-text available
The Web 2.0, GRID applications and more recently semantic desktop applications are bringing the Web to a situation where more and more data and metadata are shared and made available to large user groups. Things are further complicated by the highly unpredictable and autonomous dynamics of data, users, permissions and access control rules. For this...
Conference Paper
Full-text available
We investigate the temporal extension of the description logic DL-Litebool(RN) with the until operator on concepts, rigid (time-independent) and local (time-dependent) roles, and rigid TBox axioms. Using an embedding into the one-variable fragment of first-order temporal logic and the quasimodel technique, we prove that (i) the satisfiability probl...
Article
Full-text available
The recently introduced series of description logics under the common moniker 'DL-Lite' has attracted attention of the description logic and semantic web communities due to the low computational complexity of inference, on the one hand, and the ability to represent conceptual modeling formalisms, on the other. The main aim of this article is to car...
Article
Full-text available
Relation Based Access Control (RelBAC) is an access control model designed for the new scenarios of access control onWeb 2.0. Under this model, we discuss in this paper how to formalize with Description Logics the typical authorization problems of access control together with the enforcement of an important security property: Separation of Duties (...
Conference Paper
Full-text available
Description logics (DLs) have recently been used to provide access to large amounts of data through a high-level conceptual interface, which is of relevance to both data integration and ontology-based data access. The fundamental inference service in this case is answering queries by taking into account the axioms
Conference Paper
Full-text available
Many types of temporalised description logics (DLs) have been suggested and investigated in the past 15 years. We refer the reader to the survey papers and monograph [9, 14, 3, 16], where the history of the development of both interval and point-based temporal extensions of DLs is discussed in full detail.
Conference Paper
Full-text available
In this paper we extend the logic DL-LiteNbool and its fragments with (i) role inclusions, (ii) qualified number restrictions and (iii) role disjointness, symmetry, asymmetry, reflexivity and irreflexivity constraints. We show that if the interaction of (qualified) number restrictions with role inclusions is restricted in a way similar to DL-LiteA...
Conference Paper
Full-text available
This chapter considers the different temporal constructs appeared in the literature of temporal conceptual models ( timestamping and evolution constraints ), and it provides a coherent model-theoretic formalisation for them. It then introduces a correct and succinct encoding in a subset of first-order temporal logic, namely ${{\mathcal DLR}_{\mathc...
Article
Full-text available
Many types of part-whole relations have been proposed in the literature to aid the conceptual modeller to choose the most appropriate type, but many of those relations lack a formal specification to give clear and unambiguous semantics to them. To remedy this, a formal taxonomy of types of mereological and meronymic part-whole relations is pre...
Conference Paper
Full-text available
A recurring problem in conceptual modelling and ontology development is the representation of part-whole relations, with a requirement to be able to distinguish between essential and mandatory parts. To solve this problem, we formally characterize the semantics of these shareability notions by resorting to the temporal conceptual model ERVT and it...
Conference Paper
Full-text available
We show that reasoning in the temporal conceptual model ERV T, a fragment ofERV T that only allows timestamping is complete for 2-ExpTime. The membership,result is based on an embedding,of the conceptual model into the description logic S5ALCQI. Hardness is obtained by reducing a fragment of S5ALCQI, namely S5ALC with global roles only, toERV T.
Conference Paper
Full-text available
Representing part-whole relations and effectively using them in domain ontologies and conceptual data models poses multiple challenges. In this paper we face the issue of representing the notions of \emph{essential} and \emph{immutable} parts and wholes in addition to the usual \emph{mandatory} participation of the part or whole in the part-wh...
Article
This chapter focuses on formally representing life cycle semantics of part-whole relations in conceptual data models by utilizing the temporal modality. We approach this by resorting to the temporal conceptual data modeling language ERvt and extend it with the novel notion of status relations. This enables a precise axiomatization of the constraint...
Article
Many types of part-whole relations have been proposed in the literature to aid the conceptual modeller to choose the most appropriate type, but many of those relations lack a formal specification to give clear and unambiguous semantics to them. To remedy this, a formal taxonomy of types of mereological and meronymic part-whole relations is presente...
Article
Full-text available
This paper presents a semantic foundation of temporal conceptual models used to design temporal information systems. We consider a modelling language able to express both timestamping and evolution constraints. We conduct a deeper investigation of evolution constraints, eventually devising a model-theoretic semantics for a full-fledged model with b...
Conference Paper
Full-text available
It is known that for temporal languages, such as first-order LTL, reasoning about constant (time-independent) relations is almost always undecidable. This applies to temporal description logics as well: constant binary relations together with general concept subsumptions in combinations of LTL and the basic description logic ALC cause undecidabilit...
Conference Paper
Full-text available
We investigate the complexity of reasoning over various fragments of the Extended Entity-Relationship (EER) language, which include dierent combinations of the constructors for isa between concepts and relationships, disjointness, covering, cardinality constraints and their renement. Specically, we show that reasoning over EER diagrams with isa bet...
Conference Paper
Full-text available
The use of ontologies in various application domains, such as Data Integration, the Semantic Web, or ontology-based data man- agement, where ontologies provide the access to large amounts of data, is posing challenging requirements w.r.t. the trade-o between the ex- pressive power of a Description Logic and the eciency of reasoning. The logics of t...
Conference Paper
Full-text available
We investigate the computational complexity of reasoning over var- ious fragments of the Extended Entity-Relationship (EER) language, which in- cludes a number of constructs: ISA between entities and relationships, disjoint- ness and covering of entities and relationships, cardinality constraints for enti- ties in relationships and their refinement...
Conference Paper
Full-text available
The use of ontologies in various application domains, such as Data Integration, the Semantic Web, or ontology-based data management, where ontologies provide the access to large amounts of data, is posing challenging requirements w.r.t. a trade-off between expressive power of a DL and efficiency of reasoning. The logics of the DL-Lite family were s...
Chapter
Taxonomic reasoning is a typical inference task performed by many AI knowledge representation systems. We illustrate the effectiveness of taxonomic reasoning techniques as an active support to knowledge acquisition and schemas design in the advanced database environment LOGIDATA+, supporting complex objects and a rule-based language. The developed...
Chapter
We present a prototype of the Italian version of WordNet, a general computational lexical resource. Some relevant extensions are discussed to make it usable for parsing: in particular we add verbal selectional restrictions to make lexical discrimination effective. Italian WordNet has been coupled with a parser and a number of experiments have been...
Chapter
In this paper we give a syntax and define a denotational semantics for describing classes in LOGIDATA*, and give a subsumption algorithm that is sound, complete, and polynomial. The syntax allows us to describe both primitive and defined acyclic classes by means of the tuple and set type constructors; in particular, it is also possible to state car...
Chapter
This paper deals with furnishing object-oriented database models with a paradigm of taxonomic reasoning, i.e., an inference capability characteristic of the knowledge representation systems developed within the KL-ONE family. This particular ability is based on subsumption computation, i.e., on deducing subset relationships among classes from their...
Article
Full-text available
This paper introduces a temporal class diagram language useful to model temporal varying data. The atemporal portion of the language contains the core constructors available in both EER diagrams and UML class diagrams. The temporal part of the language is able to distin- guish between temporal and atemporal constructs, and it has the ability to rep...
Conference Paper
This paper deals with endowing object-oriented data models with taxonomic reasoning, i.e., an inference capability characteristic of the knowledge representation systems developed within the KL-ONE family. For this purpose, the main point is to introduce the concept of defined class, i.e., class whose structural description gives necessary and suff...
Conference Paper
Full-text available
This paper presents a semantic foundation of temporal conceptual models used to design temporal information systems. We consider a modeling language able to express both timestamping and evolution constraints. We conduct a deeper investigation on evolution constraints, eventually devising a model-theoretic semantics for a full-fledged model with bo...
Conference Paper
Full-text available
We combine the modal logic S5 with the description logic (DL) ALCQI. The resulting multi-dimensional DL S5ALCQI supports reasoning about change by allowing to express that concepts and roles change over time. It cannot, however, discriminate between changes in the past and in the future. Our main technical result is that satisfiability of S5ALCQI c...
Chapter
Temporal extensions of Description Logics (DL) are relevant to capture the evolving behaviour of dynamic domains, and they have been extensively considered in the literature. Several approaches for representing and reasoning with time dependent concepts have been proposed. In this chapter a summary of the temporal logic based approaches and of the...
Conference Paper
Full-text available
This paper formally clarifies the relevant reasoning problems for temporal EER diagrams. We distinguish between the following reasoning services: (a) entity, relationship and schema satisfiability; (b) liveness and global satisfiability for both entities and relationships; (c) subsumption for either entities or relationships; and (d) logical implic...
Article
this paper we deal with Extended Entity-Relationship (EER) diagrams used to model temporal databases. The temporal conceptual model ER V T has been introduced both to formally clarify the meaning of the various temporal constructs appeared in the literature [2, 4], and to check the possibility to perform reasoning on top of temporal schemas [5]. ER...
Article
This paper introduces a new logical formalism, intended for temporal conceptual modelling, as a natural combination of the well-known description logic and point-based linear temporal logic with Since and Until. We define a query language (where queries are non-recursive Datalog programs and atoms are complex expressions) and investigate the proble...
Conference Paper
Full-text available
In the first part of this Chapter we will introduce a general tempo- rally enhanced conceptual data model able to represent time varying data, in the spirit of a temporally enhanced Entity-Relationship data model. In the second part, we will introduce an object-oriented conceptual data model enriched with schema change operators, which are able to...
Conference Paper
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This paper introduces a new logical formalism, intended for temporal conceptual modelling, as a natural combination of the well-known description logic \( \mathcal{D}\mathcal{L}\mathcal{R} \)and point-based linear temporal logic with Since and Until.We define a query language (where queries are non-recursive Datalog programs and atoms are complex \...
Article
Full-text available
Recent efforts in the Conceptual Modelling community have been devoted to properly cap-ture time-varying information. Various tempo-rally enhanced Entity-Relationship (ER) mod-els have been proposed that are intended to model the temporal aspects of database con-ceptual schemas. This preliminary work gives a logical formalisation of the various pro...
Article
Recent eorts in the Conceptual Modelling community have been devoted to properly capturing time-varying information. Various temporally enhanced Entity-Relationship (ER) models have been proposed that are intended to model the temporal aspects of database conceptual schemas. This work gives a logical formalisation of the various properties that cha...
Article
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this paper is an example of external method
Article
This paper surveys the temporal extensions of description logics appearearing in the literature. The analysis considers a large spectrum of approaches appearearing in the temporal description logics area: from the loosely coupled approaches – which comprise, for example, the enhancement of simple description logics with a constraint based mechanism...
Article
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A temporal logic for representing and reasoning on a robotic domain is presented. Actions are represented by describing what is true while the action itself is occurring, and plans are constructed by temporally relating actions and world states. The temporal language is a member of the family of Description Logics, which are characterized by high e...
Conference Paper
Full-text available
This paper introduces a new logical formalism, intended for temporal conceptual modelling, as a natural combination of the well-known description logic DLR and point-based linear temporal logic with Since and Until. We define a query language (where queries are non-recursive Datalog programs and atoms are complex DLR US expressions) and investigate...
Article
Full-text available
. This paper introduces a new logical formalism, intended for temporal conceptual modelling, as a natural combination of the well-known description logic DLR and point-based linear temporal logic with Since and Until. The expressive power of the resulting DLRUS logic is illustrated by providing a systematic formalisation of the most important tempo...