The amount of available data in the neuroscience community is growing rapidly, and is approaching the point where researchers can no longer keep up. This paper describes the development of the Modeler's Workspace,...
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The amount of available data in the neuroscience community is growing rapidly, and is approaching the point where researchers can no longer keep up. This paper describes the development of the Modeler's Workspace, a digital library system we are building to improve the researcher's means of accessing, managing and sharing neuroscience data. The Workspace consists of a distributed system of heterogeneous databases, and a Java front-end for data mining and visualization. A three-tier architecture with CORBA as the middleware facilitates database federation. We discuss our design choices, and some sociological issues, such as how to encourage data submission and ensure security and quality control. (C) 1999 Elsevier Science B.V. All rights reserved.
Deductive databases result from the integration of relational database and logic programming techniques. However, significant problems remain inherent in this simple synthesis from the language point of view. In this ...
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Deductive databases result from the integration of relational database and logic programming techniques. However, significant problems remain inherent in this simple synthesis from the language point of view. In this paper, we discuss these problems from four different aspects: complex values, object orientation, higher-orderness, and updates. In each case, we examine four typical languages that address the corresponding issues.
Wrappers export the schema and data of existing heterogeneous databases and support queries on them. In the context of cooperative information systems, we present a flexible approach to specify the derivation of objec...
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Wrappers export the schema and data of existing heterogeneous databases and support queries on them. In the context of cooperative information systems, we present a flexible approach to specify the derivation of object-oriented (OO) export databases from local relational databases. Our export database derivation consists of a set of extent derivation structures (EDS) which defines the extent and deep extent of export classes. Having well-defined semantics, the EDS can be readily used in transforming wrapper queries to local queries. Based on the EDS, we developed a wrapper query evaluation strategy which handles OO queries on the export databases. The strategy is unique in that it considers the limited query processing capabilities of local database systems as well as the language constraints on the local query languages. (C) 1999 Elsevier Science B.V. All rights reserved.
In temporal contexts, information entities are not physically discarded from the database after they are modified. This non-deletion rule allows the recovery of past states of the database while a consistency history ...
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In temporal contexts, information entities are not physically discarded from the database after they are modified. This non-deletion rule allows the recovery of past states of the database while a consistency history management guarantees the data validity in each instant of time. This paper describes a data model which introduces the above mentioned time features in an object-oriented environment. In our model, called TVOO, objects and the relationships between them are time dependent and the history of the changes which occur in the database are kept in Version hierarchies. (C) 1999 Elsevier Science Inc. All rights reserved.
We present an approach to handle incremental materialization of object-oriented views. Queries that define views are implemented as methods that are invoked to compute corresponding views. To avoid computation from sc...
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We present an approach to handle incremental materialization of object-oriented views. Queries that define views are implemented as methods that are invoked to compute corresponding views. To avoid computation from scratch each time a view is accessed, we introduce some deferred update algorithms that reflect for a view only related modifications introduced into the database while that view was inactive. A view is updated by considering modifications performed within all classes along the inheritance and class-composition subhierarchies rooted at every class used in deriving that view. To each class, we add a modification list to keep one modification tuple per view dependent on that class. Such a tuple acts as a reference point that marks the start of the next update to the corresponding view. (C) 1999 Elsevier Science B.V. All rights reserved.
Case-based reasoning (CBR) systems define knowledge in terms of a memory or library of past cases and a retrieval mechanism that revolves around retrieving data relevant to a goal query. Additionally, such systems emp...
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Case-based reasoning (CBR) systems define knowledge in terms of a memory or library of past cases and a retrieval mechanism that revolves around retrieving data relevant to a goal query. Additionally, such systems employ an adaptation component that transforms the retrieved data into a solution to the problem expressed by the original query. The combination of goal query and the subsequent solution transformation is referred to as CBR goal query. Goal queries are concerned with data that is close to the request expressed in the query. Conventional relational and object-oriented databases are usually concerned specific queries. Extending conventional object-oriented data models,:this paper proposes a concept-oriented data model that provides a variety of mechanisms to support conventional goal and CBR goal queries. It is shown that such a concept-oriented data model could be used as the core for a more general knowledge base management system. (C) 1999 Elsevier Science B.V. All rights reserved.
This paper presents a framework for checking and maintaining type safety in the presence of method evolution. A method update often affects all components of the method, including the inter face and the implementation...
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This paper presents a framework for checking and maintaining type safety in the presence of method evolution. A method update often affects all components of the method, including the inter face and the implementation. The type safety problem is addressed as two levels of type consistency. The first level relates to the type checking of methods in the context of the class inheritance hierarchy, and concerns the semantics of the polymorphism of methods. The second level considers the implementation parts of methods by capturing and preserving the semantics of the chain of calling relationships among relevant methods. A graph-based approach is used to achieve this two-level type consistency required at the level of class inheritance hierarchy and the level of method invocation. We demonstrate that the two levels of type consistency checking combined provide a better control of the run-time type error problems.
A concurrent design can be used to improve productivity and quality by means of shortening product development time and sharing design information. In order to share information among designers, an object-oriented dat...
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A concurrent design can be used to improve productivity and quality by means of shortening product development time and sharing design information. In order to share information among designers, an object-oriented database management system, which has shown promising capabilities in engineering data processing, is used as a foundation for building a concurrent design architecture in this research. The architecture allows multiple designers to work on the design concurrently, store multiple versions of the design, integrate design information, and evolve the design structure. A procedure of plastic filling injection moulding is used to demonstrate the process of concurrent design, and is compared with the process of C-MOLD, a simulation analysis software package for plastic injection moulding, to show the superiority of the proposed concurrent design architecture.
object-oriented database systems (OODBMS) are well known for modeling complex and dynamic application domains. Typically OODBMS have to handle large and complex structured objects whose values and structures can chang...
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object-oriented database systems (OODBMS) are well known for modeling complex and dynamic application domains. Typically OODBMS have to handle large and complex structured objects whose values and structures can change frequently. Consequently there is a high demand for systems which support temporal and versioning features in both objects (or database population) and schema. This paper presents a mechanism for accessing the temporal versioned objects stored in the database which supports schema versioning. The results shown here can be considered as a value-added extension of our model called TVOO described in detail in [1] and [2]. in contrast to conventional database models, in TVOO objects and classes are not physically discarded from the database after they are modified or deleted. They are time dependent and the history of the changes which occur on them are kept as Version hierarchies. Therefore our model enriches the database environment with temporal and versioning features. Also, an access mechanism which makes it possible to access any object under any schema version is defined in such a way that not only objects created under old versions of schema classes can be accessed from new versions, but also objects created by new schema class versions can be accessed from old versions of the respective class.
In this paper, a fuzzy object-oriented Data model (FOOD) is defined based on the extension of a Graph-based object model (D. Lucarella and A. Zanzi "A graph-oriented data model," in Database and Expert Syste...
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In this paper, a fuzzy object-oriented Data model (FOOD) is defined based on the extension of a Graph-based object model (D. Lucarella and A. Zanzi "A graph-oriented data model," in Database and Expert Systems Applications, R. Wagner and H. Toma, Eds., Springer-Verlag, Berlin, 1996, pp. 197-206), in order to manage both crisp and imperfect *** These capabilities are requisites of many current applications dealing with data of different nature and with complex interrelationships. The model is based on a visual paradigm which supports both the representation of the data semantics and the direct browsing of the information. In the extended model both the database scheme and instances are represented as directed labeled graphs in which the fuzzy and uncertain information has its own representation. (C) 1999 John Wiley & Sons, Inc.
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