In this work, we deal with temporal abstraction of clinical data. Abstractions are, for example, blood pressure state (e.g. normal, high, low) and trend (e.g. increasing, decreasing and stationary) over time intervals...
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In this work, we deal with temporal abstraction of clinical data. Abstractions are, for example, blood pressure state (e.g. normal, high, low) and trend (e.g. increasing, decreasing and stationary) over time intervals. The goal of our work is to provide clinicians with automatic tools to extract high-level, concise, important features of available collections of time-stamped clinical data. This capability is especially important when the available collections constantly increase in size, as in long-term clinical follow-up, leading to information overload. The approach we propose exploits the integration of the deductive and object-oriented approaches in clinical databases. The main result of this work is an object-oriented data model based on the event calculus to support temporal abstraction. The proposed approach has been validated building the CARDIOTABS system for the abstraction of clinical data collected during echocardiographic tests. (C) 1999 Elsevier Science B.V. All rights reserved.
Active database systems provide facilities that monitor and respond to changes of relevance to the database. Active behaviour is normally described using Event Condition Action rules (ECA-rules), and a number of syste...
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Active database systems provide facilities that monitor and respond to changes of relevance to the database. Active behaviour is normally described using Event Condition Action rules (ECA-rules), and a number of systems have been developed, based upon different data models, that support such rules. However, experience using active databases shows that while such systems are powerful and potentially useful in many applications, they are hard to program and liable to exhibit poor performance at runtime. This document addresses both of these issues by examining both analysis and optimisation of active rules in the context of a powerful active database system. It is shown how rule analysis methods developed for straightforward active rule languages for relational data models can be extended to take account of rich event description languages and more powerful execution models. It is also shown how the results of analyses can be exploited by rule optimisers, and that multiple query optimisation can be applied in a range of circumstances to eliminate duplicated work during rule processing. Copyright (C) 1999 Published by Elsevier Science Ltd.
Active database systems support mechanisms that enable them to respond automatically to events that are taking place either inside or outside the database system itself. Considerable effort has been directed towards i...
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Active database systems support mechanisms that enable them to respond automatically to events that are taking place either inside or outside the database system itself. Considerable effort has been directed towards improving understanding of such systems in recent years, and many different proposals have been made and applications suggested. This high level of activity has not yielded a single agreed-upon standard approach to the integration of active functionality with conventional database systems, but has led to improved understanding of active behavior description languages, execution models, and architectures. This survey presents the fundamental characteristics of active database systems, describes a collection of representative systems within a common framework, considers the consequences for implementations of certain design decisions, and discusses tools for developing active applications.
The Ode object-oriented database system supports the creation and manipulation of objects with versions. Versioning is orthogonal to type - any object in the database can be versioned at any time, and the same code wo...
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The Ode object-oriented database system supports the creation and manipulation of objects with versions. Versioning is orthogonal to type - any object in the database can be versioned at any time, and the same code works on both versioned and non-versioned instances. object versioning is supported by many object-oriented databases (e.g. Gemstone, objectStore, Versant). However, the facilities are often complex and may not quite match application requirements. Furthermore, the implementation techniques are not well-documented. Ode took the approach of designing a minimal set of versioning primitives with which users can specify the exact policy they require. To illustrate the flexibility and power of these versioning facilities, we use them to implement a set of previously suggested versioning capabilities. We describe how these versioning facilities are implemented, and discuss our experience in using them. Copyright (C) 1999 John Whey & Sons, Ltd.
This paper develops a solution to the problem of importing existing TEI data into an existing object-oriented database schema without changing the TEI data or the database schema. The solution is based on architectura...
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This paper develops a solution to the problem of importing existing TEI data into an existing object-oriented database schema without changing the TEI data or the database schema. The solution is based on architectural processing. Two meta-DTDs are used, one to define the architectural forms for the object model and another to map the existing SGML data onto those forms. A full example using a critical text in TEI markup is developed.
In the paper a model of the object-oriented database system is presented for archiving results generated with particles simulations and for retrieving simulation results from the database system for further processing.
ISBN:
(纸本)3540658211
In the paper a model of the object-oriented database system is presented for archiving results generated with particles simulations and for retrieving simulation results from the database system for further processing.
object-oriented databases (OODBs) have been used for many advanced applications requiring advanced modeling power. In this paper, a locking-based concurrency control scheme is presented for OODBs. The proposed scheme ...
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ISBN:
(纸本)3540664858
object-oriented databases (OODBs) have been used for many advanced applications requiring advanced modeling power. In this paper, a locking-based concurrency control scheme is presented for OODBs. The proposed scheme reduces locking overhead for class hierarchy which is an important property in OODBs. While existing schemes show good performance only for specific applications, the proposed scheme can incur less locking overhead for any applications. For the performance evaluation of the proposed scheme, simulation is conducted using 007 benchmark. Through the simulation, the proposed scheme is compared with the two existing techniques. The performance studies show that the proposed scheme is superior to existing works.
A family of the ODMG object Models is proposed as a solution to the problems of the ODMG Standard related to the type systems, the model of persistence, and the model semantics. This family is intended to replace the ...
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ISBN:
(纸本)3540664858
A family of the ODMG object Models is proposed as a solution to the problems of the ODMG Standard related to the type systems, the model of persistence, and the model semantics. This family is intended to replace the existing single and inadequate ODMG object Model. Unlike the ODMG Standard, all the models in this family are equipped with orthogonal persistence. The most basic model in the family corresponds to the Java(TM) programming language. A strictly more sophisticated model features the form of parametric polymorphism suitable for object-oriented database technology. The next model in the hierarchy is equipped with type-safe reflective capabilities. The most sophisticated model is enriched with a logic-based constraint language that is completely missing from the ODMG Standard. Each model in the family is well-defined and avoids the inconsistencies of the ODMG object Model.
Research in the parallel and scientific computing area has begun to focus on the development of Java-based programming environments. This paper describes the design of an original object-oriented database-style reposi...
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ISBN:
(纸本)3540658211
Research in the parallel and scientific computing area has begun to focus on the development of Java-based programming environments. This paper describes the design of an original object-oriented database-style repository interface for high performance storage and retrieval of scientific data. The design is based on the standard interface to objectdatabases that has been defined by tho object Database Management Group. In the paper, we present the mapping of the repository interface into Java constructs.
Various proposals have been made to extend object-oriented languages and database systems with roles because they allow to weaken strict typing concepts and therefore can. provide mechanisms for an object to change it...
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ISBN:
(纸本)0769500846
Various proposals have been made to extend object-oriented languages and database systems with roles because they allow to weaken strict typing concepts and therefore can. provide mechanisms for an object to change its type during its lifetime. But this tie-called object migration is not the only advantage offered by a suitable role model. This paper studies the possibilities to use roles for a general change management system that also includes support for schema evolution. OPAQUE, as the selected role model, can be ea:tended with schema update mechanisms in a surprisingly clean and straightforward way including the concepts of versions and views as well.
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