The Experts below are selected from a list of 42 Experts worldwide ranked by ideXlab platform

L. Libkin - One of the best experts on this subject based on the ideXlab platform.

  • Temporal logics over unranked trees
    20th Annual IEEE Symposium on Logic in Computer Science (LICS' 05), 2005
    Co-Authors: P. Barcelo, L. Libkin
    Abstract:

    We consider unranked trees that have become an active subject of study recently due to XML applications, and characterize commonly used fragments of first-order (FO) and monadic second-order logic (MSO) for them via various temporal logics. We look at both unordered trees and ordered trees (in which children of the same node are ordered by the next-Sibling Relation), and characterize Boolean and unary FO and MSO queries. For MSO Boolean queries, we use extensions of the /spl mu/-calculus: with counting for unordered trees, and with the past for ordered. For Boolean FO queries, we use similar extensions of CTL*. We then use composition techniques to transfer results to unary queries. For the ordered case, we need the same logics as for Boolean queries, but for the unordered case, we need to add both past and counting to the /spl mu/-calculus and CTL*. We also consider MSO Sibling-invariant queries, that can use the Sibling ordering but do not depend on the particular one used, and capture them by a variant of the /spl mu/-calculus with modulo quantifiers.

  • LICS - Temporal logics over unranked trees
    20th Annual IEEE Symposium on Logic in Computer Science (LICS' 05), 2005
    Co-Authors: P. Barcelo, L. Libkin
    Abstract:

    We consider unranked trees that have become an active subject of study recently due to XML applications, and characterize commonly used fragments of first-order (FO) and monadic second-order logic (MSO) for them via various temporal logics. We look at both unordered trees and ordered trees (in which children of the same node are ordered by the next-Sibling Relation), and characterize Boolean and unary FO and MSO queries. For MSO Boolean queries, we use extensions of the /spl mu/-calculus: with counting for unordered trees, and with the past for ordered. For Boolean FO queries, we use similar extensions of CTL*. We then use composition techniques to transfer results to unary queries. For the ordered case, we need the same logics as for Boolean queries, but for the unordered case, we need to add both past and counting to the /spl mu/-calculus and CTL*. We also consider MSO Sibling-invariant queries, that can use the Sibling ordering but do not depend on the particular one used, and capture them by a variant of the /spl mu/-calculus with modulo quantifiers.

P. Barcelo - One of the best experts on this subject based on the ideXlab platform.

  • Temporal logics over unranked trees
    20th Annual IEEE Symposium on Logic in Computer Science (LICS' 05), 2005
    Co-Authors: P. Barcelo, L. Libkin
    Abstract:

    We consider unranked trees that have become an active subject of study recently due to XML applications, and characterize commonly used fragments of first-order (FO) and monadic second-order logic (MSO) for them via various temporal logics. We look at both unordered trees and ordered trees (in which children of the same node are ordered by the next-Sibling Relation), and characterize Boolean and unary FO and MSO queries. For MSO Boolean queries, we use extensions of the /spl mu/-calculus: with counting for unordered trees, and with the past for ordered. For Boolean FO queries, we use similar extensions of CTL*. We then use composition techniques to transfer results to unary queries. For the ordered case, we need the same logics as for Boolean queries, but for the unordered case, we need to add both past and counting to the /spl mu/-calculus and CTL*. We also consider MSO Sibling-invariant queries, that can use the Sibling ordering but do not depend on the particular one used, and capture them by a variant of the /spl mu/-calculus with modulo quantifiers.

  • LICS - Temporal logics over unranked trees
    20th Annual IEEE Symposium on Logic in Computer Science (LICS' 05), 2005
    Co-Authors: P. Barcelo, L. Libkin
    Abstract:

    We consider unranked trees that have become an active subject of study recently due to XML applications, and characterize commonly used fragments of first-order (FO) and monadic second-order logic (MSO) for them via various temporal logics. We look at both unordered trees and ordered trees (in which children of the same node are ordered by the next-Sibling Relation), and characterize Boolean and unary FO and MSO queries. For MSO Boolean queries, we use extensions of the /spl mu/-calculus: with counting for unordered trees, and with the past for ordered. For Boolean FO queries, we use similar extensions of CTL*. We then use composition techniques to transfer results to unary queries. For the ordered case, we need the same logics as for Boolean queries, but for the unordered case, we need to add both past and counting to the /spl mu/-calculus and CTL*. We also consider MSO Sibling-invariant queries, that can use the Sibling ordering but do not depend on the particular one used, and capture them by a variant of the /spl mu/-calculus with modulo quantifiers.

Dan Roth - One of the best experts on this subject based on the ideXlab platform.

  • Exploiting the wikipedia structure in local and global classification of taxonomic Relations
    Natural Language Engineering, 2012
    Co-Authors: Quang Xuan, Dan Roth
    Abstract:

    Determining whether two terms have an ancestor Relation (e.g. Toyota Camry and car) or a Sibling Relation (e.g. Toyota and Honda) is an essential component of textual inference in Natural Language Processing applications such as Question Answering, Summarization, and Textual Entailment. Significant work has been done on developing knowledge sources that could support these tasks, but these resources usually suffer from low coverage, noise, and are inflexible when dealing with ambiguous and general terms that may not appear in any stationary resource, making their use as general purpose background knowledge resources difficult. In this paper, rather than building a hierarchical structure of concepts and Relations, we describe an algorithmic approach that, given two terms, determines the taxonomic Relation between them using a machine learning-based approach that makes use of existing resources. Moreover, we develop a global constraint-based inference process that leverages an existing knowledge base to enforce Relational constraints among terms and thus improves the classifier predictions. Our experimental evaluation shows that our approach significantly outperforms other systems built upon the existing well-known knowledge sources.

  • EMNLP - Constraints Based Taxonomic Relation Classification
    2010
    Co-Authors: Quang Do, Dan Roth
    Abstract:

    Determining whether two terms in text have an ancestor Relation (e.g. Toyota and car) or a Sibling Relation (e.g. Toyota and Honda) is an essential component of textual inference in NLP applications such as Question Answering, Summarization, and Recognizing Textual Entailment. Significant work has been done on developing stationary knowledge sources that could potentially support these tasks, but these resources often suffer from low coverage, noise, and are inflexible when needed to support terms that are not identical to those placed in them, making their use as general purpose background knowledge resources difficult. In this paper, rather than building a stationary hierarchical structure of terms and Relations, we describe a system that, given two terms, determines the taxonomic Relation between them using a machine learning-based approach that makes use of existing resources. Moreover, we develop a global constraint optimization inference process and use it to leverage an existing knowledge base also to enforce Relational constraints among terms and thus improve the classifier predictions. Our experimental evaluation shows that our approach significantly outperforms other systems built upon existing well-known knowledge sources.

Jeanne Magagna - One of the best experts on this subject based on the ideXlab platform.

  • Envy, jealousy, love, and generosity in Sibling Relations: The impact of Sibling Relations on future family Relations
    2014
    Co-Authors: Jeanne Magagna
    Abstract:

    In this chapter, I assume that, just as we have an external family and many other important Relations, in our internal world we have an internalised family with Relations existing between the self and the internalised family members and other important people in our lives. Such internalised family members might be different from external family members, for they "are always coloured by our phantasies and projections" . Bearing this in mind, I focus on both external and internalised Sibling Relations and their influence on family life. I look at the tricky question of when, how, and whether or not to intervene in a Sibling Relation to help the Siblings develop a healthier future. I also look at what can happen when unhealthy Sibling Relations are internalised and later provide the impetus for re-enactment in adult life. In addition, I discuss how we can use dream analysis to observe and repair the internalised damaged Sibling Relations and, thus, promote the development of loving and more thoughtful intimate Relations.

Rethinaswamy Nadarajan - One of the best experts on this subject based on the ideXlab platform.

  • OTM Workshops - A Prufer Sequence Based Approach to Measure Structural Similarity of XML Documents
    Lecture Notes in Computer Science, 2013
    Co-Authors: Ramanathan Periakaruppan, Rethinaswamy Nadarajan
    Abstract:

    XML is a W3C standard for exchange of semi-structured data. For many applications it is necessary to extract information from semi-structured data which is a complex task. In this paper we address the problem of computing structural similarity of XML documents which play a crucial role in clustering process. Previous works on path based approach fail to capture the Sibling Relationship among the nodes and also ignore the similarity when the nodes in the paths to be matched, are not in the same order but still convey same semantics. Another weakness of this approach is in the case of the partial path match, is that the level information is not taken into account when the nodes to be compared appear in different hierarchical level. To address these issues, we describe a method based on Prufer Sequence for measuring the structural similarity of XML documents, in this paper. Benefit of Prufer sequence based representation is that, it stores the ancestor-descendant and Sibling Relation. XML trees are encoded based on Prufer sequence which establishes a one-to-one mapping between XML tree and sequence. Instead of extracting all paths only common nodes are extracted based on Prufer sequence code. We have devised an algorithm to compute similarity by exploring all Relations among the common nodes namely parent-child, ancestor-descendant and Sibling. The experimental results show that the proposed approach is effective.