Pontifical Catholic University of Rio de Janeiro

Displaying 1-40 of 111 results

  • White Papers // Apr 2015

    RUBYA: a Tool for Generating Rules for Incremental Maintenance of RDF Views

    In this paper, the authors present Rubya, a tool that automatically generates the RDF (Resource Description Framework) view defined on top of relational data and all rules required for the incremental maintenance of the RDF view. Their approach relies on the designer to specify a mapping between the relational schema...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Mar 2015

    R2BA: Rationalizing R2RML Mapping by Assertion

    The W3C RDB2RDF working group proposed R2RML as a standard mapping language that defines how to publish data stored in relational databases as RDF (Resource Description Framework) triples. However, R2RML mappings are sometimes difficult to understand, which may affect the users' understanding of the transformations the original data suffer until...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Dec 2014

    Specification and Incremental Maintenance of Linked Data Mashup Views

    The Linked Data initiative promotes the publication of previously isolated databases as interlinked RDF (Resource Description Framework) datasets, thereby creating a global scale data space, known as the Web of data. Linked data mashup applications, which consume data from the multiple linked data sources in the Web of data, are...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Oct 2014

    Discovering Frequent Mobility Patterns on Moving Object Data

    In this paper, the authors consider the problem of efficiently discovering and detecting frequent mobility patterns on moving object data. Their proposed approach is key for mobility applications, such as applications that need to discover and explain movement patterns of a set of moving objects (e.g. traffic management, birds migration...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Aug 2014

    A Framework for Incremental Maintenance of RDF Views of Relational Data

    A general and flexible way to publish relational data in RDF (Resource Description Framework) format is to create RDF views of the underlying relational data. In this paper, the authors demonstrate a framework, based on rules, for the incremental maintenance of RDF views defined on top of relational data. They...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Jun 2014

    The Role of Design Rationale in the Ontology Matching Step during the Triplification of Relational Databases

    A common task when publishing relational databases as RDF (Resource Description Framework) datasets is to automatically define a vocabulary using the schema data, called Database Schema Ontology (DSO). To automatically reuse terms from existing vocabularies, Ontology Matching (OM) algorithms are used to generate recommendations for the DSO vocabulary. However, when...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Jun 2014

    On Materialized sameAs Linksets

    The linked data initiative promotes the publication of previously isolated databases as interlinked RDF (Resource Description Framework) datasets, thereby creating a global scale data space. Datasets are frequently interlinked using some automated matching process that results in a materialized sameAs linkset, that is, a set of links of the form...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Apr 2014

    A Metadata Focused Crawler for Linked Data

    The linked data best practices recommend publishers of triplesets to use well-known ontologies in the triplication process and to link their triplesets with other triplesets. However, despite the fact that extensive lists of open ontologies and triplesets are available, most publishers typically do not adopt those ontologies and link their...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Apr 2014

    Distant Supervision for Relation Extraction using Ontology Class Hierarchy-Based Features

    Relation extraction is a key step in the problem of structuring natural language text. This paper demonstrates a multi-class classifier for relation extraction, constructed using the distant supervision approach, along with resources of the semantic Web. In particular, the classifier uses a feature based on the class hierarchy of an...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Apr 2014

    SCS Connector - Quantifying and Visualising Semantic Paths between Entity Pairs

    A key challenge of the semantic Web lies in the creation of semantic links between Web resources. The creation of links serves as a mean to semantically enrich Web resources, connecting disparate information sources and facilitating data reuse and sharing. As the amount of data on the Web is ever...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Apr 2014

    TRTML - A Tripleset Recommendation Tool based on Supervised Learning Algorithms

    The linked data initiative promotes the publication of inter-linked RDF (Resource Description Framework) triplesets, thereby creating a global scale data space. However, to enable the creation of such data space, the publisher of a tripleset t must be aware of other triplesets that the user can interlink with t. Towards...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Mar 2014

    RecLAK: Analysis and Recommendation of Interlinking Datasets

    In this paper, the authors present the RecLAK, a Web application developed for the LAK Challenge 2014. RecLAK focuses on the analysis of the LAK dataset metadata and provides recommendations of potential candidate datasets to be interlinked with the LAK dataset. RecLAK follows an approach to generate recommendations based on...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Feb 2014

    Publishing Deep Web Geographic Data

    In this paper, the authors introduce a design process, called W-RayS, to describe deep web geographic data and to publish the descriptions both on the Web of data and on the surface Web. The paper also outlines a toolkit that supports the process and discusses an experiment in which the...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Jan 2014

    A Monitored NoC with Runtime Path Adaptation

    Network-on-Chips (NoCs) are already a common choice of communication infrastructure for complex System-on-Chips (SoCs) containing a large number of processing resources and with critical communication requirements. A NoC provides several advantages, such as higher scalability, efficient energy management, higher bandwidth and lower average latency, when compared to bus-based systems. Experiments...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Jan 2014

    Tool-Set for NoC-Based MPSoC Debugging - A Protocol View Perspective

    Software development becomes an important issue in today's MPSoC design. Due to the inherent non-deterministic behavior of MPSoCs, they are prone to concurrency bugs. Debugging tools for MPSoC may be grouped in the following classes: simulators, parallel software development environments, NoC debuggers. An important gap is observed concerning a complete...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Jan 2014

    Runtime Fault Recovery Protocol for NoC-Based MPSoCs

    The design of reliable MPSoCs is mandatory to cope with faults during fabrication or product lifetime. For instance, permanent faults on the interconnect network can stall or crash applications even though the network has alternative fault-free paths to a given destination. This paper presents a novel fault-tolerant communication protocol that...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Jan 2014

    A Framework for MPSoC Generation and Distributed Applications Evaluation

    The huge design space to develop the hardware/software infrastructure of MPSoCs (Multi-Processor System-on-Chip), or to evaluate the performance of applications requires frameworks able to generate and to simulate the MPSoC. The design of MPSoCs is a complex task. From the designer side point of view, a new feature inserted into...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Jan 2014

    Wrapper Design for the Reuse of Functional Interconnect for Test

    In this paper, the authors propose a wrapper design for interconnects with guaranteed bandwidth and latency services and on-chip protocol. They demonstrate that these interconnects abstract the interconnect details and provide predictability in the data transfer, which are desirable not only for the functional domain but also for the test...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Dec 2013

    Evaluating the Trade-Off Between DVFS Energy-Savings and Virtual Networks Performance

    Data centers usually employ virtualization techniques coupled with other techniques, such as Dynamic Voltage and Frequency Scaling (DVFS), in order to reduce overall energy consumption. However, changes in processor frequency may impact the network performance, specifically in metrics such as throughput and jitter. This paper evaluates the trade-off between changes...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Sep 2013

    Phoenix NoC: A Distributed Fault Tolerant Architecture

    The advances in deep submicron technology have made the development of large Multi-Processor System-on-Chip (MPSoC) possible and Network-on-Chips (NoCs) have been recognized to provide efficient communication architecture for such systems. With the positive effects on the device's integration some drawbacks arise, such as the increase of fault susceptibility during the...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Sep 2013

    Achieving QoS in NoC-Based MPSoCs Through Dynamic Frequency Scaling

    The management of Quality-of-Service (QoS) constraints in NoC-based MPSoCs, with dozens of tasks running simultaneously, is still a challenge. Techniques applied at design or run-time to address this issue adopts different QoS metrics. Designers include in their systems monitoring techniques, adapting at run-time the QoS parameters to cope with the...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Sep 2013

    Adaptive QoS Techniques for NoC-Based MPSoCs

    With the significant increase in the number of processing elements in NoC-based MPSoCs, communication becomes, increasingly, a critical resource for performance gains and QoS guarantees. The main gap observed in the NoC-based MPSoCs literature is the runtime adaptive techniques to meet QoS. In the absence of such techniques, the system...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Aug 2013

    Evaluating the Scalability of Test Buses

    Intra-chip communication architectures evolved from buses to networks-on-chip, in order to provide design scalability and increased bandwidth. However, the predominant test architecture for SoCs is still based on buses. While this approach presents advantages, such as simple design and a mature set of automation tools, its scalability is questionable. This...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Aug 2013

    Incremental Maintenance of RDF Views of Relational Data

    In this paper, the authors propose an incremental maintenance strategy, based on rules, for RDF (Resource Description Framework) views defined on top of relational data. The first step relies on the designer to specify a mapping between the relational schema and target ontology and results in a specification of how...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Jul 2013

    Profiling of Linked Datasets using Structured Descriptions

    While there exists an increasingly large number of linked data, metadata about the content covered by individual datasets is sparse. In this paper, the authors introduce a processing pipeline to automatically assess, annotate and index available linked datasets. Given a minimal description of a dataset from the DataHub, the process...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Jul 2013

    Cite4Me: A Semantic Search and RetrievalWeb Application for Scientific Publications

    Cite4Me is a Web application that leverages semantic Web technologies to provide a new perspective on search and retrieval of bibliographical data. The Web application presented in this paper focuses on: semantic recommendation of papers; novel semantic search & retrieval of papers; data interlinking of bibliographical data with related data...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Jul 2013

    TSV Multiplexing: A 3D NoC Occupancy Analysis

    Network-on-Chips (NoCs) are proposed as promising packet-based communication platforms for Multi-Processor System-on-Chip (MPSoC) design, due to scalability, better throughput and reduced power consumption. NoC-based architectures are characterized by various trade-offs with regard to structural characteristics, performance specifications, and application demands. However, increasing the number of cores over a 2D plane...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Jun 2013

    LiChEn: Automated Electrical Characterization of Asynchronous Standard Cell Libraries

    Semi-custom design flows are a key factor for the rapid growth of integrated circuits and systems. They lower design complexity through the use of pre-designed and pre-characterized functional components called standard cells, instead of assuming that designers have to draw, place and connect each transistor. In this paper, modeling of...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Jun 2013

    Comparing Recommendation Approaches for Dataset Interlinking

    Whenever a dataset is published on the Web-of-data, an exploratory search over the datasets already published must be performed to link resources. To tackle this problem, this paper introduces and compares two approaches for selecting datasets that most likely can be linked to that being published. The methods use Bayesian...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Jun 2013

    StdTrip+K: Design Rationale in the RDB-to-RDF process

    The design rationale behind the triplification of a relational database is a valuable information source, especially for the process of interlinking published triplesets. Indeed, studies show that the arbitrary use of the owl: sameAs property, without carrying context information regarding the triplesets to be linked, has jeopardized the reuse of...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // May 2013

    Determining the Test Sources/Sinks for NoC TAMs

    Conventional approaches using the Network-on-Chip (NoC) as Test Access Mechanism (TAM), called NoC TAM, model the test sources/sinks and the routing algorithm as constraints to the test scheduling, reducing its efficiency. This paper is based on a new NoC TAM model where these constraints do not exist, potentially resulting in...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // May 2013

    Distributed Resource Management in NoC-Based MPSoCs with Dynamic Cluster Sizes

    Scalability is an important issue in large MPSoCs. MPSoCs may execute several applications in parallel, with dynamic workload, and tight QoS constraints. Thus, the MPSoC management must be distributed to cope with such constraints. In this paper, the authors present a distributed resource management in NoC-based MPSoC, using a clustering...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Apr 2013

    Identifying Candidate Datasets for Data Interlinking

    Over the past years there has been a considerable movement toward publishing data on the Web following the linked data principles. One of the design principles that can stimulate the growth and increase the usefulness of the Web of data is URIs linkage. However, the related URIs is typically in...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Mar 2013

    QEF-LD: A Query Engine for Distributed Query Processing on Linked Data

    The Web of linked data forms a single, globally distributed Web. Querying this dataspace poses new challenges that are not addressed by traditional research on federated query processing. Linked data integration applications must meet the requirements of efficient query processing in the distributed setting. This paper presents Query Evaluation Framework...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Mar 2013

    Interlinking Documents Based on Semantic Graphs

    Connectivity and relatedness of Web resources are two concepts that define to what extent different parts are connected or related to one another. Measuring connectivity and relatedness between Web resources is a growing field of research, often the starting point of recommender systems. Although relatedness is liable to subjective interpretations,...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Mar 2013

    R2RML by Assertion: A Semi-Automatic Tool for Generating Customised R2RML Mappings

    In this paper, the authors demonstrate the RBA (R2RML By Assertion) tool which automatically generates customized R2RML mappings based on a set of semantic mappings that model the relationship between the relational database schema and target ontology in RDF (Resource Description Framework). The semantic mappings are specified by a set...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Mar 2013

    ASCEnD: A Standard Cell Library for Semi-Custom Asynchronous Design

    The asynchronous circuit design paradigm provides a practical solution for several challenges and constraints of current and future technologies to build integrated circuits and systems. However, there is little electronic design automation support for this paradigm. This work presents a standard cell library designed to support a semi-custom approach in...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Mar 2013

    Combining a Co-Occurrence-Based and a Semantic Measure for Entity Linking

    One key feature of the Semantic Web lies in the ability to link related Web resources. However, while relations within particular datasets are often well-defined, links between disparate datasets and corpora of Web resources are rare. The increasingly widespread use of cross-domain reference datasets, such as Freebase and DBpedia for...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Feb 2013

    Complex Matching of RDF Datatype Properties

    Property mapping is a fundamental component of ontology matching and yet there is little support that goes beyond the identification of single property matches. Real data often requires some degree of composition, trivially exemplified by the mapping of "First name", "Last name" to "Full name" on one end, to complex...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Jan 2013

    As Simple as It Gets - A Sentence Simplifier for Different Learning Levels and Contexts

    In this paper, the authors present a text simplification method that transforms complex sentences into simplified forms. Their method uses NLP-techniques to simplify the text based on the target audience context, improving its overall understandability. They evaluate their approach in two aspects: grammatical structure and understandability. In both aspects, their...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // May 2011

    Server Consolidation With Migration Control for Virtualized Data Centers

    Virtualization has become a key technology for simplifying service management and reducing energy costs in data centers. One of the challenges faced by data centers is to decide when, how, and which Virtual Machines (VMs) have to be consolidated into a single physical server. Server consolidation involves VM migration, which...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Aug 2010

    Optimization Under Uncertainty For Operational Planning Of Petroleum Refineries

    In this paper, author describe a Nonlinear Programming (NLP) model for operational planning of oil refineries, considering uncertainties related to oil supply and refinery capacity. Three mathematical models based on stochastic programming (two-stage stochastic model) and robust programming (min-max regret model and max-min model) are developed to address these uncertainties....

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Sep 2007

    Similarity and Analogy over Application Domains

    Databases, particularly when storing heterogeneous, sparse semi-structured data, tend to provide incomplete information and information which is difficult to categorize. This paper first considers how to classify entity instances as members of entity classes organized in a lattice-like generalization/specialization hierarchy. Then, it describes how the frame representation employed for instances...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // May 2007

    Modeling Provenance for Semantic Desktop Applications

    As the volumes of digital resources grow exponentially, users face the threat of information overload. Almost everything everyone sees, read, hear, write and measure is collected and made available via computational information systems. The problem is not so much finding information, but rather, developing computational solutions that help manage digital...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Mar 2012

    Surfacing Scientific and Financial Data with the Xcel2RDF Plug-In

    Given the astounding amount of data stored in spreadsheets and relational databases, a critical requirement for the evolution of the Semantic Web (SW) is the ability to convert data to SW compatible formats, such as RDF Resource Description Framework and OWL (Web Ontology Language). The process by which data is...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Aug 2012

    Operations over Lightweight Ontologies

    The best practices for Linked Data design recommend reusing known ontologies. However, the process of reusing ontology involves two issues: selecting a set of terms from the ontology vocabulary; and using the ontology constraints to derive those that apply to such terms. The first issue is quite simple and corresponds...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Aug 2006

    On the Complexity of Process Pipeline Scheduling

    In this paper, the authors explore how process pipeline scheduling may become a viable strategy for executing workflows. It first details a workflow optimization and execution algorithm that reduces runtime space. The optimization strategy pipelines the communication between as many processes as possible, within the bounds of the storage space...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // May 2006

    Automatic Generation of SQL/XML Views

    In this paper, the authors propose an approach to generate XML views of relational data, using SQL/XML. The paper first specifies the conditions for a set of correspondence assertions to fully specify the view in terms of the relational schema and, if so, they show that the mappings defined by...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Jun 2006

    Transactional Behavior of a Workflow Instance

    Workflow management systems usually interpret a workflow definition rigidly, allowing no deviations during execution. However, there are real life situations where users should be allowed to deviate from the prescribed static workflow definition for various reasons, including lack of information about parameter values and unavailability of the required resources. To...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Oct 2007

    Conceptual Modeling by Analogy and Metaphor

    In this paper, the authors argue in favor of a database conceptual schema and Semantic Web ontology design discipline that explores analogy mappings to reuse the structure and integrity constraints of conceptual models, stored in a repository. They presuppose that a team of expert conceptual designers would build a standard...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Sep 2008

    Matching Object Catalogues

    A catalogue holds information about a set of objects, typically classified using terms taken from a given thesaurus and described with the help of a set of attributes. Matching a pair of catalogues means to find a relationship between the terms of their thesauri and a relationship between their attributes....

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Oct 2008

    Applying Analogy to Schema Generation

    To support the generation of database schemas of information systems, a five-step design process is proposed that explores the notions of generic and blended spaces and favors the reuse of predefined schemas. The use of generic and blended spaces is essential to achieve the passage from the source space into...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Apr 2014

    TRTML - A Tripleset Recommendation Tool based on Supervised Learning Algorithms

    The linked data initiative promotes the publication of inter-linked RDF (Resource Description Framework) triplesets, thereby creating a global scale data space. However, to enable the creation of such data space, the publisher of a tripleset t must be aware of other triplesets that the user can interlink with t. Towards...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Apr 2014

    Distant Supervision for Relation Extraction using Ontology Class Hierarchy-Based Features

    Relation extraction is a key step in the problem of structuring natural language text. This paper demonstrates a multi-class classifier for relation extraction, constructed using the distant supervision approach, along with resources of the semantic Web. In particular, the classifier uses a feature based on the class hierarchy of an...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Oct 2014

    Discovering Frequent Mobility Patterns on Moving Object Data

    In this paper, the authors consider the problem of efficiently discovering and detecting frequent mobility patterns on moving object data. Their proposed approach is key for mobility applications, such as applications that need to discover and explain movement patterns of a set of moving objects (e.g. traffic management, birds migration...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Mar 2014

    RecLAK: Analysis and Recommendation of Interlinking Datasets

    In this paper, the authors present the RecLAK, a Web application developed for the LAK Challenge 2014. RecLAK focuses on the analysis of the LAK dataset metadata and provides recommendations of potential candidate datasets to be interlinked with the LAK dataset. RecLAK follows an approach to generate recommendations based on...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Aug 2014

    A Framework for Incremental Maintenance of RDF Views of Relational Data

    A general and flexible way to publish relational data in RDF (Resource Description Framework) format is to create RDF views of the underlying relational data. In this paper, the authors demonstrate a framework, based on rules, for the incremental maintenance of RDF views defined on top of relational data. They...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Apr 2014

    A Metadata Focused Crawler for Linked Data

    The linked data best practices recommend publishers of triplesets to use well-known ontologies in the triplication process and to link their triplesets with other triplesets. However, despite the fact that extensive lists of open ontologies and triplesets are available, most publishers typically do not adopt those ontologies and link their...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Feb 2014

    Publishing Deep Web Geographic Data

    In this paper, the authors introduce a design process, called W-RayS, to describe deep web geographic data and to publish the descriptions both on the Web of data and on the surface Web. The paper also outlines a toolkit that supports the process and discusses an experiment in which the...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Apr 2014

    SCS Connector - Quantifying and Visualising Semantic Paths between Entity Pairs

    A key challenge of the semantic Web lies in the creation of semantic links between Web resources. The creation of links serves as a mean to semantically enrich Web resources, connecting disparate information sources and facilitating data reuse and sharing. As the amount of data on the Web is ever...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Apr 2015

    RUBYA: a Tool for Generating Rules for Incremental Maintenance of RDF Views

    In this paper, the authors present Rubya, a tool that automatically generates the RDF (Resource Description Framework) view defined on top of relational data and all rules required for the incremental maintenance of the RDF view. Their approach relies on the designer to specify a mapping between the relational schema...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Mar 2013

    QEF-LD: A Query Engine for Distributed Query Processing on Linked Data

    The Web of linked data forms a single, globally distributed Web. Querying this dataspace poses new challenges that are not addressed by traditional research on federated query processing. Linked data integration applications must meet the requirements of efficient query processing in the distributed setting. This paper presents Query Evaluation Framework...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Jan 2013

    As Simple as It Gets - A Sentence Simplifier for Different Learning Levels and Contexts

    In this paper, the authors present a text simplification method that transforms complex sentences into simplified forms. Their method uses NLP-techniques to simplify the text based on the target audience context, improving its overall understandability. They evaluate their approach in two aspects: grammatical structure and understandability. In both aspects, their...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Mar 2013

    Combining a Co-Occurrence-Based and a Semantic Measure for Entity Linking

    One key feature of the Semantic Web lies in the ability to link related Web resources. However, while relations within particular datasets are often well-defined, links between disparate datasets and corpora of Web resources are rare. The increasingly widespread use of cross-domain reference datasets, such as Freebase and DBpedia for...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Feb 2013

    Complex Matching of RDF Datatype Properties

    Property mapping is a fundamental component of ontology matching and yet there is little support that goes beyond the identification of single property matches. Real data often requires some degree of composition, trivially exemplified by the mapping of "First name", "Last name" to "Full name" on one end, to complex...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Jun 2013

    StdTrip+K: Design Rationale in the RDB-to-RDF process

    The design rationale behind the triplification of a relational database is a valuable information source, especially for the process of interlinking published triplesets. Indeed, studies show that the arbitrary use of the owl: sameAs property, without carrying context information regarding the triplesets to be linked, has jeopardized the reuse of...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Jul 2012

    Three Decades of Research on Database Design at PUC-Rio

    Research on database design at PUC-Rio dates back to the late seventies and covers a broad range of topics, from the early development of the relational model to recent applications of semiotic concepts to the design and specification of information systems. This paper briefly reviews some of the major contributions...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Apr 2012

    Proactive Monitoring of Moving Objects

    Positioning systems, combined with inexpensive communication technologies, open interesting possibilities to implement real-time applications that monitor moving objects and that support decision making. This paper first discusses basic requirements for proactive real-time monitoring applications. Then, it proposes architecture to deploy applications that monitor moving objects, are pro-active, explore trajectory semantics...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Oct 2010

    From Conceptual Modeling to Logical Representation of Trajectories in SGBDOR and DW Systems

    With the growth of mobile devices equipped with geographical localization services, it has become economical and technically feasible to capture moving object trajectories in real life. Many interesting applications are being developed based on trajectory analysis. For example, in a traffic management system, traffic jams may be determined by mining...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Oct 2011

    The Role of Constraints in Linked Data

    In this paper, the authors argues that a Linked Data source should publish an application ontology that includes a set of constraints that capture the semantics of the classes and properties used to model the data. Furthermore, if the Linked Data source publishes a mapping between its vocabulary and the...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Mar 2011

    Query Processing in a Mediator based Framework for Linked Data Integration

    In this paper, the authors present a three-level mediator based framework for linked data integration. In their approach, the mediated schema is represented by a domain ontology, which provides a conceptual representation of the application. Each relevant data source is described by source ontology, published on the Web according to...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Jun 2014

    The Role of Design Rationale in the Ontology Matching Step during the Triplification of Relational Databases

    A common task when publishing relational databases as RDF (Resource Description Framework) datasets is to automatically define a vocabulary using the schema data, called Database Schema Ontology (DSO). To automatically reuse terms from existing vocabularies, Ontology Matching (OM) algorithms are used to generate recommendations for the DSO vocabulary. However, when...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Jun 2014

    On Materialized sameAs Linksets

    The linked data initiative promotes the publication of previously isolated databases as interlinked RDF (Resource Description Framework) datasets, thereby creating a global scale data space. Datasets are frequently interlinked using some automated matching process that results in a materialized sameAs linkset, that is, a set of links of the form...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Dec 2014

    Specification and Incremental Maintenance of Linked Data Mashup Views

    The Linked Data initiative promotes the publication of previously isolated databases as interlinked RDF (Resource Description Framework) datasets, thereby creating a global scale data space, known as the Web of data. Linked data mashup applications, which consume data from the multiple linked data sources in the Web of data, are...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Mar 2015

    R2BA: Rationalizing R2RML Mapping by Assertion

    The W3C RDB2RDF working group proposed R2RML as a standard mapping language that defines how to publish data stored in relational databases as RDF (Resource Description Framework) triples. However, R2RML mappings are sometimes difficult to understand, which may affect the users' understanding of the transformations the original data suffer until...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Jul 2012

    RDB2RDF: A Relational to RDF Plug-in for Eclipse

    In this paper, the authors introduced an extensible Eclipse plug-in that converts relational data to RDF (Resource Description Framework). On one hand, as the proposed standard for the RDB2RDF conversion process is still unstable, the proposed architecture should be extensible and welcoming to change. On the other hand, a large...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Jun 2013

    Comparing Recommendation Approaches for Dataset Interlinking

    Whenever a dataset is published on the Web-of-data, an exploratory search over the datasets already published must be performed to link resources. To tackle this problem, this paper introduces and compares two approaches for selecting datasets that most likely can be linked to that being published. The methods use Bayesian...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Mar 2013

    R2RML by Assertion: A Semi-Automatic Tool for Generating Customised R2RML Mappings

    In this paper, the authors demonstrate the RBA (R2RML By Assertion) tool which automatically generates customized R2RML mappings based on a set of semantic mappings that model the relationship between the relational database schema and target ontology in RDF (Resource Description Framework). The semantic mappings are specified by a set...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Aug 2013

    Incremental Maintenance of RDF Views of Relational Data

    In this paper, the authors propose an incremental maintenance strategy, based on rules, for RDF (Resource Description Framework) views defined on top of relational data. The first step relies on the designer to specify a mapping between the relational schema and target ontology and results in a specification of how...

    Provided By Pontifical Catholic University of Rio de Janeiro

  • White Papers // Mar 2013

    Interlinking Documents Based on Semantic Graphs

    Connectivity and relatedness of Web resources are two concepts that define to what extent different parts are connected or related to one another. Measuring connectivity and relatedness between Web resources is a growing field of research, often the starting point of recommender systems. Although relatedness is liable to subjective interpretations,...

    Provided By Pontifical Catholic University of Rio de Janeiro