The Experts below are selected from a list of 23412 Experts worldwide ranked by ideXlab platform
Wei Wang - One of the best experts on this subject based on the ideXlab platform.
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repairing functional dependency violations in distributed data
Database Systems for Advanced Applications, 2015Co-Authors: Qing Chen, Chu He, Wei WangAbstract:One of the problems central to data consistency is data repairing. Given a database \(D\) violating a set \(\Sigma \) of data dependencies as data quality rules, it aims to modify \(D\) for a new relation \(D'\) satisfying \(\Sigma \). When \(D\) is a centralized database, a host of methods have been provided to address this problem. In practice, a database may be fragmented and distributed to multiple sites, which is advocated by distributed systems for better scalability and is readily supported by commercial systems. This paper makes a first effort to develop techniques for repairing functional dependency violations in a horizontally partitioned database. (1) Based on a message-passing distributed computing model and two complexity measures (parallel time and data shipment) for distributed algorithms, we study data repairing with equivalence classes in the distributed setting. We show that it is NP-completeto build equivalence classes when the data is horizontally partitioned, and when we aim to minimize either data shipment or parallel computation time. (2) Despite the intractability, we propose efficient distributed algorithms and optimization techniques for data repairing based on equivalence classes. (3) We experimentally verify the effectiveness and efficiency of our algorithms, using both real-life and synthetic data.
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DASFAA (1) - Repairing functional dependency Violations in Distributed Data
Database Systems for Advanced Applications, 2015Co-Authors: Qing Chen, Zijing Tan, Chaofeng Sha, Wei WangAbstract:One of the problems central to data consistency is data repairing. Given a database \(D\) violating a set \(\Sigma \) of data dependencies as data quality rules, it aims to modify \(D\) for a new relation \(D'\) satisfying \(\Sigma \). When \(D\) is a centralized database, a host of methods have been provided to address this problem. In practice, a database may be fragmented and distributed to multiple sites, which is advocated by distributed systems for better scalability and is readily supported by commercial systems. This paper makes a first effort to develop techniques for repairing functional dependency violations in a horizontally partitioned database. (1) Based on a message-passing distributed computing model and two complexity measures (parallel time and data shipment) for distributed algorithms, we study data repairing with equivalence classes in the distributed setting. We show that it is NP-completeto build equivalence classes when the data is horizontally partitioned, and when we aim to minimize either data shipment or parallel computation time. (2) Despite the intractability, we propose efficient distributed algorithms and optimization techniques for data repairing based on equivalence classes. (3) We experimentally verify the effectiveness and efficiency of our algorithms, using both real-life and synthetic data.
Tian Hong - One of the best experts on this subject based on the ideXlab platform.
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Inferior strong functional dependency and inference rules for XML
Electronic Design Engineering, 2012Co-Authors: Tian HongAbstract:For solving logical implication problem for XML inferior strong functional dependency under incomplete information circumstances,inferior strong functional dependency and inference rules for XML based on XML Schema were discussed.The concepts of XML Schema and incomplete XML document tree according with XML Schema were formalized.Based on the concepts of sub-tree information equivalence,sub-tree information consistent,the definition of XML inferior strong functional dependency was given and its property was studied.Inference rules for XML inferior strong functional dependency were presented,its soundness were given.The production in this work lays the foundation for normalization of XML Schema existing XML inferior strong functional dependency under incomplete information circumstances.
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XML weak functional dependency and inference rule based on XML Schema
Journal of Computer Applications, 2010Co-Authors: Tian HongAbstract:To solve the logical implication problem of Extensible Markup Language ( XML) weak functional dependency under incomplete information circumstances, the weak functional dependency and inference rules for XML based on XML Schema were discussed. The concepts of XML Schema and incomplete XML document tree conforming to XML Schema were formalized. Based on the concepts of subtree information equivalence and subtree information consistency, the definition of XML weak functional dependency was given and its properties were studied. A set of inference rules for XML weak functional dependency was presented and its soundness and completeness were given. This work is foundation of normalizing XML Schema with XML weak functional dependency under incomplete information circumstances.
Olebjorn Tysnes - One of the best experts on this subject based on the ideXlab platform.
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validation of a updrs mds updrs based definition of functional dependency for parkinson s disease
Parkinsonism & Related Disorders, 2020Co-Authors: Neil Ramsay, Angus D Macleod, Guido Alves, Marta Camacho, Lars Forsgren, Rachael A Lawson, Jodi Maplegrodem, Olebjorn TysnesAbstract:Abstract Introduction functional dependency in basic activities of daily living (ADLs) is a key outcome in Parkinson's disease (PD). We aimed to define dependency in PD, using the original and MDS versions of the Unified Parkinson's Disease Rating Scale (UPDRS). Methods We developed two algorithms to define dependency from items of UPDRS Part 2 and MDS-UPDRS Part 2 relating to basic ADLs (feeding, dressing, hygiene and walking, and getting out of a chair). We validated both algorithms using data from 1110 patients from six community-based PD incidence cohorts, testing concurrent validity, convergent validity, and predictive validity. Results Our optimal algorithm showed high specificity and moderate to high sensitivity versus Schwab & England Discussion We have demonstrated the concurrent validity, convergent validity, and predictive validity of a UPDRS-/MDS-UPDRS-based algorithm to define functional dependency in PD. This can be used for studying dependency in any study where UPDRS or MDS-UPDRS part 2 data have been collected.
Qing Chen - One of the best experts on this subject based on the ideXlab platform.
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repairing functional dependency violations in distributed data
Database Systems for Advanced Applications, 2015Co-Authors: Qing Chen, Chu He, Wei WangAbstract:One of the problems central to data consistency is data repairing. Given a database \(D\) violating a set \(\Sigma \) of data dependencies as data quality rules, it aims to modify \(D\) for a new relation \(D'\) satisfying \(\Sigma \). When \(D\) is a centralized database, a host of methods have been provided to address this problem. In practice, a database may be fragmented and distributed to multiple sites, which is advocated by distributed systems for better scalability and is readily supported by commercial systems. This paper makes a first effort to develop techniques for repairing functional dependency violations in a horizontally partitioned database. (1) Based on a message-passing distributed computing model and two complexity measures (parallel time and data shipment) for distributed algorithms, we study data repairing with equivalence classes in the distributed setting. We show that it is NP-completeto build equivalence classes when the data is horizontally partitioned, and when we aim to minimize either data shipment or parallel computation time. (2) Despite the intractability, we propose efficient distributed algorithms and optimization techniques for data repairing based on equivalence classes. (3) We experimentally verify the effectiveness and efficiency of our algorithms, using both real-life and synthetic data.
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DASFAA (1) - Repairing functional dependency Violations in Distributed Data
Database Systems for Advanced Applications, 2015Co-Authors: Qing Chen, Zijing Tan, Chaofeng Sha, Wei WangAbstract:One of the problems central to data consistency is data repairing. Given a database \(D\) violating a set \(\Sigma \) of data dependencies as data quality rules, it aims to modify \(D\) for a new relation \(D'\) satisfying \(\Sigma \). When \(D\) is a centralized database, a host of methods have been provided to address this problem. In practice, a database may be fragmented and distributed to multiple sites, which is advocated by distributed systems for better scalability and is readily supported by commercial systems. This paper makes a first effort to develop techniques for repairing functional dependency violations in a horizontally partitioned database. (1) Based on a message-passing distributed computing model and two complexity measures (parallel time and data shipment) for distributed algorithms, we study data repairing with equivalence classes in the distributed setting. We show that it is NP-completeto build equivalence classes when the data is horizontally partitioned, and when we aim to minimize either data shipment or parallel computation time. (2) Despite the intractability, we propose efficient distributed algorithms and optimization techniques for data repairing based on equivalence classes. (3) We experimentally verify the effectiveness and efficiency of our algorithms, using both real-life and synthetic data.
Guido Alves - One of the best experts on this subject based on the ideXlab platform.
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validation of a updrs mds updrs based definition of functional dependency for parkinson s disease
Parkinsonism & Related Disorders, 2020Co-Authors: Neil Ramsay, Angus D Macleod, Guido Alves, Marta Camacho, Lars Forsgren, Rachael A Lawson, Jodi Maplegrodem, Olebjorn TysnesAbstract:Abstract Introduction functional dependency in basic activities of daily living (ADLs) is a key outcome in Parkinson's disease (PD). We aimed to define dependency in PD, using the original and MDS versions of the Unified Parkinson's Disease Rating Scale (UPDRS). Methods We developed two algorithms to define dependency from items of UPDRS Part 2 and MDS-UPDRS Part 2 relating to basic ADLs (feeding, dressing, hygiene and walking, and getting out of a chair). We validated both algorithms using data from 1110 patients from six community-based PD incidence cohorts, testing concurrent validity, convergent validity, and predictive validity. Results Our optimal algorithm showed high specificity and moderate to high sensitivity versus Schwab & England Discussion We have demonstrated the concurrent validity, convergent validity, and predictive validity of a UPDRS-/MDS-UPDRS-based algorithm to define functional dependency in PD. This can be used for studying dependency in any study where UPDRS or MDS-UPDRS part 2 data have been collected.
