Semantic integrity in a relational data base system
Proceedings of the 1st International Conference on Very Large Data Bases, 1975
Abstract As a model of some aspect (s) of the real world, the data in a data base must be accurat... more Abstract As a model of some aspect (s) of the real world, the data in a data base must be accurate. In the context of a relational data base system, a facility to allow the expression and enforcement of a set of semantic integrity constraints is discussed. Semantic integrity ...
Many data representation structures, such as web site categories and domain ontologies, have been... more Many data representation structures, such as web site categories and domain ontologies, have been established for semantic-based information search and retrieval on the web. These structures consist of concepts and their interrelationships. Approaches to determine the similarity in semantics among concepts in data representation structures have been developed in order to facilitate information retrieval and recommendation processes. Some approaches are
In order to draw users’ attention and to increase their satisfaction towards online information s... more In order to draw users’ attention and to increase their satisfaction towards online information search results, search engine developers and vendors try to predict user preference based on the user behavior. Recommendations are provided by the search engines or online vendors to the users. Recommendation systems are implemented in commercial and non-profit web sites to predict the user preferences. For
An approach to the coordinated sharing and interchange of computerized information is described e... more An approach to the coordinated sharing and interchange of computerized information is described emphasizing partial, controlled sharing among autonomous databases. Office information systems provide a particularly appropriate context for this type of information sharing and exchange. A federated database architecture is described in which a collection of independent database systems are united into a loosely coupled federation in order to share and exchange information. A federation consists of components (of which there may be any number) and a single federal dictionary. The components represent individual users, applications, workstations, or other components in an office information system. The federal dictionary is a specialized component that maintains the topology of the federation and oversees the entry of new components. Each component in the federation controls its interactions with other components by means of an export schema and an import schema. The export schema specifies the information that a component will share with other components, while the import schema specifies the nonlocal information that a component wishes to manipulate. The federated architecture provides mechanisms for sharing data, for sharing transactions (via message types) for combining information from several components, and for coordinating activities among autonomous components (via negotiation). A prototype implementation of the federated database mechanism is currently operational on an experimental basis.
The QuakeSim interdisciplinary research team has developed a federated database system, which rec... more The QuakeSim interdisciplinary research team has developed a federated database system, which records and provides portal-based access to a variety of geoscientific information important to the earthquake study and forecasting process. This includes fault, seismicity, and other information key to modeling earthquakes and tsunamis. Through the QuakeSim portal, scientists can discover relevant information, and access, visualize, and import data to simulation programs and other codes. This is accomplished by utilizing an inter-connected (federated) set of ontologies to describe the semantics of the information and the inter-relationships among the data. Data are recorded in source form with error estimates included, are geotagged as appropriate to specify precisely where on the globe the data were obtained, and are converted as necessary for use by scientists. Data is delivered by the use of a suite of Web Services tied to the semantic metadata (ontology) specifications. A primary goal of the QuakeTables federated database is to provide an integrated resource for simulation and modeling software, such as GeoFest and Virtual California. A key feature of QuakeTables is to allow for multiple fault interpretations, which can be tested in the models and simulations. As such, QuakeTables does not define a standard set of faults, but allows users to select faults from standard sets, from research publications, or from user-defined attributes. At present, the system is being enhanced to include GPS and InSAR data
An Approach to Object Sharing in Distributed Datbase Systems
Very Large Data Bases, 1983
This paper describes DODM, a simple model for object sharing in distributed database,systems. The... more This paper describes DODM, a simple model for object sharing in distributed database,systems. The model,provides a small set of operations for object definition, manipulation, and retrieval in a distributed environment.,Relationships among oojects can be established across database boundarres, objects are relocatable within the distributed environment, and mechanisms,are provided,for object sharing among,individual databases.,An object naming,convention,supports,location transparent object references; that is,
Semantic integrity in a relational data base system
Proceedings of the 1st International Conference on Very Large Data Bases, 1975
Abstract As a model of some aspect (s) of the real world, the data in a data base must be accurat... more Abstract As a model of some aspect (s) of the real world, the data in a data base must be accurate. In the context of a relational data base system, a facility to allow the expression and enforcement of a set of semantic integrity constraints is discussed. Semantic integrity ...
Many data representation structures, such as web site categories and domain ontologies, have been... more Many data representation structures, such as web site categories and domain ontologies, have been established for semantic-based information search and retrieval on the web. These structures consist of concepts and their interrelationships. Approaches to determine the similarity in semantics among concepts in data representation structures have been developed in order to facilitate information retrieval and recommendation processes. Some approaches are
In order to draw users’ attention and to increase their satisfaction towards online information s... more In order to draw users’ attention and to increase their satisfaction towards online information search results, search engine developers and vendors try to predict user preference based on the user behavior. Recommendations are provided by the search engines or online vendors to the users. Recommendation systems are implemented in commercial and non-profit web sites to predict the user preferences. For
An approach to the coordinated sharing and interchange of computerized information is described e... more An approach to the coordinated sharing and interchange of computerized information is described emphasizing partial, controlled sharing among autonomous databases. Office information systems provide a particularly appropriate context for this type of information sharing and exchange. A federated database architecture is described in which a collection of independent database systems are united into a loosely coupled federation in order to share and exchange information. A federation consists of components (of which there may be any number) and a single federal dictionary. The components represent individual users, applications, workstations, or other components in an office information system. The federal dictionary is a specialized component that maintains the topology of the federation and oversees the entry of new components. Each component in the federation controls its interactions with other components by means of an export schema and an import schema. The export schema specifies the information that a component will share with other components, while the import schema specifies the nonlocal information that a component wishes to manipulate. The federated architecture provides mechanisms for sharing data, for sharing transactions (via message types) for combining information from several components, and for coordinating activities among autonomous components (via negotiation). A prototype implementation of the federated database mechanism is currently operational on an experimental basis.
The QuakeSim interdisciplinary research team has developed a federated database system, which rec... more The QuakeSim interdisciplinary research team has developed a federated database system, which records and provides portal-based access to a variety of geoscientific information important to the earthquake study and forecasting process. This includes fault, seismicity, and other information key to modeling earthquakes and tsunamis. Through the QuakeSim portal, scientists can discover relevant information, and access, visualize, and import data to simulation programs and other codes. This is accomplished by utilizing an inter-connected (federated) set of ontologies to describe the semantics of the information and the inter-relationships among the data. Data are recorded in source form with error estimates included, are geotagged as appropriate to specify precisely where on the globe the data were obtained, and are converted as necessary for use by scientists. Data is delivered by the use of a suite of Web Services tied to the semantic metadata (ontology) specifications. A primary goal of the QuakeTables federated database is to provide an integrated resource for simulation and modeling software, such as GeoFest and Virtual California. A key feature of QuakeTables is to allow for multiple fault interpretations, which can be tested in the models and simulations. As such, QuakeTables does not define a standard set of faults, but allows users to select faults from standard sets, from research publications, or from user-defined attributes. At present, the system is being enhanced to include GPS and InSAR data
An Approach to Object Sharing in Distributed Datbase Systems
Very Large Data Bases, 1983
This paper describes DODM, a simple model for object sharing in distributed database,systems. The... more This paper describes DODM, a simple model for object sharing in distributed database,systems. The model,provides a small set of operations for object definition, manipulation, and retrieval in a distributed environment.,Relationships among oojects can be established across database boundarres, objects are relocatable within the distributed environment, and mechanisms,are provided,for object sharing among,individual databases.,An object naming,convention,supports,location transparent object references; that is,
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Papers by Dennis McLeod