The Experts below are selected from a list of 1200 Experts worldwide ranked by ideXlab platform
Elisa Quintarelli - One of the best experts on this subject based on the ideXlab platform.
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Modeling temporal dimensions of Semistructured Data
Journal of Intelligent Information Systems, 2012Co-Authors: Carlo Combi, Barbara Oliboni, Elisa QuintarelliAbstract:In this paper we propose a graph-based generic model able to uniformly represent Semistructured Data and their temporal aspects. In particular, we start from a generic and expressive model proposed in the Database literature and consider in a formal and systematic way both valid time and transaction time, together with the set of temporal constraints needed to correctly manage the semantics of the represented time dimension. We then propose operations, which allow the incremental management of the proposed model satisfying the introduced temporal constraints. Moreover, we also deal with the possibility of managing together the two classical time dimensions of valid and transaction times, and formalize the set of constraints needed to correctly handle these temporal aspects together. Some examples taken from a medical scenario will be used to describe the introduced concepts.
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Applying model-checking to solve queries on Semistructured Data
Computer Languages Systems & Structures, 2009Co-Authors: Agostino Dovier, Elisa QuintarelliAbstract:The large volume and nature of Data available to the casual users and programs motivate the increasing interest of the Database community in studying flexible and efficient techniques for extracting and querying Semistructured Data. On the other hand, efficient methods have been discovered for solving the so-called model-checking problem for some modal logics. The aim of this paper is to show how some of these methods can be used for querying Semistructured Data. For doing that we show that Semistructured Data can be naturally seen as Kripke Transition Systems. To keep the presentation independent of a specific language, we introduce a graphical query language that includes some of the features of the query languages based on graphs and patterns. We show how to associate CTL formulas to queries of this language. This allows us to see the problems of solving a query as an instance of the model-checking problem for CTL that can be solved in polynomial time. We have tested the method by using a model-checker, and have studied the applicability of the method to some existing languages for Semistructured Databases.
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A graph-based Data model to represent transaction time in Semistructured Data
Lecture Notes in Computer Science, 2004Co-Authors: Carlo Combi, Barbara Oliboni, Elisa QuintarelliAbstract:In this paper we propose the Graphical Semistructured temporal Data model (GEM), which is based on labeled graphs and allows one to represent in a uniform way Semistructured Data and their temporal aspects. In particular, we focus on transaction time.
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DEXA - A Graph-Based Data Model to Represent Transaction Time in Semistructured Data
Lecture Notes in Computer Science, 2004Co-Authors: Carlo Combi, Barbara Oliboni, Elisa QuintarelliAbstract:In this paper we propose the Graphical Semistructured teMporal Data model (GEM), which is based on labeled graphs and allows one to represent in a uniform way Semistructured Data and their temporal aspects. In particular, we focus on transaction time.
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modeling Semistructured Data by using graph based constraints
Lecture Notes in Computer Science, 2003Co-Authors: Ernesto Damiani, Barbara Oliboni, Elisa Quintarelli, Letizia TancaAbstract:The widespread adoption of Semistructured and more in particular XML Data has opened a new venue for the application of formal methods to the speci.cation of models for de.ning classes of Semistructured or XML documents [1,3]. Most current models for Semistructured Data are too speci.c to allow immediate comparison with each other, and do not easily support incremental model design. For this reason, we introduce the General Semistructured Meta-Model (GSMM), a simple meta-model for Semistructured information which can be applied for the translation to a common formalism of the various abstract models proposed in literature; this approach fosters easy a priori comparison and discussion of concrete models’ features, such as allowed sets of values, handling of object identi .ers, relationships representation; moreover, it supports e.ective inter-model translation and design. Unlike other proposals [2], our meta-model does not rely on an extension of the concept of schema; rather, GSMM is based on a generic graph that can be instantiated into a number of concrete models by providing a) values for a restricted set of parameters (labels) and b) some high-level constraints, themselves represented as graphs. Here, constraints take the role of the schema, imposing constraints directly on the structure of Semistructured Data provides the designer with a powerful tool for controlling the degree of precision of the structure and introducing .exibility at the Data representation level.
Barbara Oliboni - One of the best experts on this subject based on the ideXlab platform.
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Modeling temporal dimensions of Semistructured Data
Journal of Intelligent Information Systems, 2012Co-Authors: Carlo Combi, Barbara Oliboni, Elisa QuintarelliAbstract:In this paper we propose a graph-based generic model able to uniformly represent Semistructured Data and their temporal aspects. In particular, we start from a generic and expressive model proposed in the Database literature and consider in a formal and systematic way both valid time and transaction time, together with the set of temporal constraints needed to correctly manage the semantics of the represented time dimension. We then propose operations, which allow the incremental management of the proposed model satisfying the introduced temporal constraints. Moreover, we also deal with the possibility of managing together the two classical time dimensions of valid and transaction times, and formalize the set of constraints needed to correctly handle these temporal aspects together. Some examples taken from a medical scenario will be used to describe the introduced concepts.
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A graph-based Data model to represent transaction time in Semistructured Data
Lecture Notes in Computer Science, 2004Co-Authors: Carlo Combi, Barbara Oliboni, Elisa QuintarelliAbstract:In this paper we propose the Graphical Semistructured temporal Data model (GEM), which is based on labeled graphs and allows one to represent in a uniform way Semistructured Data and their temporal aspects. In particular, we focus on transaction time.
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DEXA - A Graph-Based Data Model to Represent Transaction Time in Semistructured Data
Lecture Notes in Computer Science, 2004Co-Authors: Carlo Combi, Barbara Oliboni, Elisa QuintarelliAbstract:In this paper we propose the Graphical Semistructured teMporal Data model (GEM), which is based on labeled graphs and allows one to represent in a uniform way Semistructured Data and their temporal aspects. In particular, we focus on transaction time.
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modeling Semistructured Data by using graph based constraints
Lecture Notes in Computer Science, 2003Co-Authors: Ernesto Damiani, Barbara Oliboni, Elisa Quintarelli, Letizia TancaAbstract:The widespread adoption of Semistructured and more in particular XML Data has opened a new venue for the application of formal methods to the speci.cation of models for de.ning classes of Semistructured or XML documents [1,3]. Most current models for Semistructured Data are too speci.c to allow immediate comparison with each other, and do not easily support incremental model design. For this reason, we introduce the General Semistructured Meta-Model (GSMM), a simple meta-model for Semistructured information which can be applied for the translation to a common formalism of the various abstract models proposed in literature; this approach fosters easy a priori comparison and discussion of concrete models’ features, such as allowed sets of values, handling of object identi .ers, relationships representation; moreover, it supports e.ective inter-model translation and design. Unlike other proposals [2], our meta-model does not rely on an extension of the concept of schema; rather, GSMM is based on a generic graph that can be instantiated into a number of concrete models by providing a) values for a restricted set of parameters (labels) and b) some high-level constraints, themselves represented as graphs. Here, constraints take the role of the schema, imposing constraints directly on the structure of Semistructured Data provides the designer with a powerful tool for controlling the degree of precision of the structure and introducing .exibility at the Data representation level.
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temporal aspects of Semistructured Data
International Symposium on Temporal Representation and Reasoning, 2001Co-Authors: Barbara Oliboni, Elisa Quintarelli, L TancaAbstract:In many applications information about the history of Data and their dynamic aspects are just as important as static information. The increasing amount of information accessible through the Web has presented new challenges to academic and industrial research on Databases. In this context, Data are either structured, when coming from relational or object-oriented Databases, or partially or completely unstructured, when they consist of simple collections of text or image files. In the context of Semistructured Data, models and query languages must be extended in order to consider dynamic aspects. We present a model based on labeled graphs for representing changes in Semistructured Data and a SQL-like query language for querying it.
Sebastian Schaffert - One of the best experts on this subject based on the ideXlab platform.
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ICLP (Technical Communications) - Simulation Unification: Beyond Querying Semistructured Data (Invited Talk)
2012Co-Authors: Francois Bry, Sebastian SchaffertAbstract:This article first reminds of simulation unification, a non-standard unification proposed at the 18th International Conference on Logic Programming (ICLP 2002) for making logic programming capable of querying Semistructured Data on the Web. This article further argues that, beyond querying Semistructured Data on the Web, simulation unification has a potential for Web querying of multimedia Data and semantic metaData and for Web searching of Data of all kinds.
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Pattern Queries for XML and Semistructured Data
2003Co-Authors: Sebastian Schaffert, Sacha Berger, Francois BryAbstract:Query and transformation languages developed since the mid 90es for XML and Semistructured Data – e.g. XQuery, the precursors of XQuery, and XSLT – built upon a path-oriented node selection: A node in a Data item is specified in terms of a root-to-node path in the manner of the file selection languages of operating systems. Constructs from regular expressions such as ∗, +, ?, and “wildcards” give rise to a flexible node retrieval from incompletely specified Data items. This paper investigates an alternative approach to querying XML and Semistructured Data. A metaphor for this approach views queries as patterns, answers as Data items matching the queries. Formally, an answer to a query is defined as a simulation [1] of an instance of the query in a Data item. The basics of the query language Xcerpt are introduced and it is given a modeltheoretic semantics. Recent results on an operational semantics are outlined. Ideas for a visual query language are finally sketched.
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ICLP - Towards a Declarative Query and Transformation Language for XML and Semistructured Data: Simulation Unification
Logic Programming, 2002Co-Authors: Francois Bry, Sebastian SchaffertAbstract:The growing importance of XML as a Data interchange standard demands languages for Data querying and transformation. Since the mid 90es, several such languages have been proposed that are inspired from functional languages (such as XSLT [1]) and/or Database query languages (such as XQuery [2]). This paper addresses applying logic programming concepts and techniques to designing a declarative, rule-based query and transformation language for XML and Semistructured Data.The paper first introduces issues specific to XML and Semistructured Data such as the necessity of flexible "query terms" and of "construct terms". Then, it is argued that logic programming concepts are particularly appropriate for a declarative query and transformation language for XML and Semistructured Data. Finally, a new form of unification, called "simulation unification", is proposed for answering "query terms", and it is illustrated on examples.
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towards a declarative query and transformation language for xml and Semistructured Data simulation unification
International Conference on Logic Programming, 2002Co-Authors: Francois Bry, Sebastian SchaffertAbstract:The growing importance of XML as a Data interchange standard demands languages for Data querying and transformation. Since the mid 90es, several such languages have been proposed that are inspired from functional languages (such as XSLT [1]) and/or Database query languages (such as XQuery [2]). This paper addresses applying logic programming concepts and techniques to designing a declarative, rule-based query and transformation language for XML and Semistructured Data.The paper first introduces issues specific to XML and Semistructured Data such as the necessity of flexible "query terms" and of "construct terms". Then, it is argued that logic programming concepts are particularly appropriate for a declarative query and transformation language for XML and Semistructured Data. Finally, a new form of unification, called "simulation unification", is proposed for answering "query terms", and it is illustrated on examples.
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towards a declarative query and transformationlanguage for xml and Semistructured Data simulation unification
Lecture Notes in Computer Science, 2002Co-Authors: Francois Bry, Sebastian SchaffertAbstract:The growing importance of XML as a Data interchange standard demands languages for Data querying and transformation. Since the mid 90es, several such languages have been proposed that are inspired from functional languages (such as XSLT [1]) and/or Database query languages (such as XQuery [2]). This paper addresses applying logic programming concepts and techniques to designing a declarative, rule-based query and transformation language for XML and Semistructured Data. The paper first introduces issues specific to XML and Semistructured Data such as the necessity of flexible “query terms” and of “construct terms”. Then, it is argued that logic programming concepts are particularly appropriate for a declarative query and transformation language for XML and Semistructured Data. Finally, a new form of unification, called “simulation unification”, is proposed for answering “query terms”, and it is illustrated on examples.
Francois Bry - One of the best experts on this subject based on the ideXlab platform.
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ICLP (Technical Communications) - Simulation Unification: Beyond Querying Semistructured Data (Invited Talk)
2012Co-Authors: Francois Bry, Sebastian SchaffertAbstract:This article first reminds of simulation unification, a non-standard unification proposed at the 18th International Conference on Logic Programming (ICLP 2002) for making logic programming capable of querying Semistructured Data on the Web. This article further argues that, beyond querying Semistructured Data on the Web, simulation unification has a potential for Web querying of multimedia Data and semantic metaData and for Web searching of Data of all kinds.
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Pattern Queries for XML and Semistructured Data
2003Co-Authors: Sebastian Schaffert, Sacha Berger, Francois BryAbstract:Query and transformation languages developed since the mid 90es for XML and Semistructured Data – e.g. XQuery, the precursors of XQuery, and XSLT – built upon a path-oriented node selection: A node in a Data item is specified in terms of a root-to-node path in the manner of the file selection languages of operating systems. Constructs from regular expressions such as ∗, +, ?, and “wildcards” give rise to a flexible node retrieval from incompletely specified Data items. This paper investigates an alternative approach to querying XML and Semistructured Data. A metaphor for this approach views queries as patterns, answers as Data items matching the queries. Formally, an answer to a query is defined as a simulation [1] of an instance of the query in a Data item. The basics of the query language Xcerpt are introduced and it is given a modeltheoretic semantics. Recent results on an operational semantics are outlined. Ideas for a visual query language are finally sketched.
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ICLP - Towards a Declarative Query and Transformation Language for XML and Semistructured Data: Simulation Unification
Logic Programming, 2002Co-Authors: Francois Bry, Sebastian SchaffertAbstract:The growing importance of XML as a Data interchange standard demands languages for Data querying and transformation. Since the mid 90es, several such languages have been proposed that are inspired from functional languages (such as XSLT [1]) and/or Database query languages (such as XQuery [2]). This paper addresses applying logic programming concepts and techniques to designing a declarative, rule-based query and transformation language for XML and Semistructured Data.The paper first introduces issues specific to XML and Semistructured Data such as the necessity of flexible "query terms" and of "construct terms". Then, it is argued that logic programming concepts are particularly appropriate for a declarative query and transformation language for XML and Semistructured Data. Finally, a new form of unification, called "simulation unification", is proposed for answering "query terms", and it is illustrated on examples.
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towards a declarative query and transformation language for xml and Semistructured Data simulation unification
International Conference on Logic Programming, 2002Co-Authors: Francois Bry, Sebastian SchaffertAbstract:The growing importance of XML as a Data interchange standard demands languages for Data querying and transformation. Since the mid 90es, several such languages have been proposed that are inspired from functional languages (such as XSLT [1]) and/or Database query languages (such as XQuery [2]). This paper addresses applying logic programming concepts and techniques to designing a declarative, rule-based query and transformation language for XML and Semistructured Data.The paper first introduces issues specific to XML and Semistructured Data such as the necessity of flexible "query terms" and of "construct terms". Then, it is argued that logic programming concepts are particularly appropriate for a declarative query and transformation language for XML and Semistructured Data. Finally, a new form of unification, called "simulation unification", is proposed for answering "query terms", and it is illustrated on examples.
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towards a declarative query and transformationlanguage for xml and Semistructured Data simulation unification
Lecture Notes in Computer Science, 2002Co-Authors: Francois Bry, Sebastian SchaffertAbstract:The growing importance of XML as a Data interchange standard demands languages for Data querying and transformation. Since the mid 90es, several such languages have been proposed that are inspired from functional languages (such as XSLT [1]) and/or Database query languages (such as XQuery [2]). This paper addresses applying logic programming concepts and techniques to designing a declarative, rule-based query and transformation language for XML and Semistructured Data. The paper first introduces issues specific to XML and Semistructured Data such as the necessity of flexible “query terms” and of “construct terms”. Then, it is argued that logic programming concepts are particularly appropriate for a declarative query and transformation language for XML and Semistructured Data. Finally, a new form of unification, called “simulation unification”, is proposed for answering “query terms”, and it is illustrated on examples.
Carlo Combi - One of the best experts on this subject based on the ideXlab platform.
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Modeling temporal dimensions of Semistructured Data
Journal of Intelligent Information Systems, 2012Co-Authors: Carlo Combi, Barbara Oliboni, Elisa QuintarelliAbstract:In this paper we propose a graph-based generic model able to uniformly represent Semistructured Data and their temporal aspects. In particular, we start from a generic and expressive model proposed in the Database literature and consider in a formal and systematic way both valid time and transaction time, together with the set of temporal constraints needed to correctly manage the semantics of the represented time dimension. We then propose operations, which allow the incremental management of the proposed model satisfying the introduced temporal constraints. Moreover, we also deal with the possibility of managing together the two classical time dimensions of valid and transaction times, and formalize the set of constraints needed to correctly handle these temporal aspects together. Some examples taken from a medical scenario will be used to describe the introduced concepts.
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A graph-based Data model to represent transaction time in Semistructured Data
Lecture Notes in Computer Science, 2004Co-Authors: Carlo Combi, Barbara Oliboni, Elisa QuintarelliAbstract:In this paper we propose the Graphical Semistructured temporal Data model (GEM), which is based on labeled graphs and allows one to represent in a uniform way Semistructured Data and their temporal aspects. In particular, we focus on transaction time.
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DEXA - A Graph-Based Data Model to Represent Transaction Time in Semistructured Data
Lecture Notes in Computer Science, 2004Co-Authors: Carlo Combi, Barbara Oliboni, Elisa QuintarelliAbstract:In this paper we propose the Graphical Semistructured teMporal Data model (GEM), which is based on labeled graphs and allows one to represent in a uniform way Semistructured Data and their temporal aspects. In particular, we focus on transaction time.
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Temporal Semistructured Data Models and Data Warehouses
Data Warehouses and OLAP, 1Co-Authors: Carlo Combi, Barbara OliboniAbstract:This chapter describes a graph-based approach to represent information stored in a Data warehouse, by means of a temporal Semistructured Data model. We consider issues related to the representation of Semistructured Data warehouses, and discuss the set of constraints needed to manage in a correct way the warehouse time, i.e. the time dimension considered storing Data in the Data warehouse itself. We use a temporal Semistructured Data model because a Data warehouse can contain Data coming from different and heterogeneous Data sources. This means that Data stored in a Data warehouse are Semistructured in nature, i.e. in different documents the same information can be represented in different ways, and moreover, the document schemata can be available or not. Moreover, information stored into a Data warehouse is often time varying, thus as for Semistructured Data, also in the Data warehouse context, it could be useful to consider time.
