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Digital libraries involve various types of data like text, audio, images and video. The data objects are typically very large and of the order of hundreds and thousands of kilobytes. In a digital library, these data objects are distributed in a wide area network. Retrieving large data objects in a wide area network has a high response time. We have conducted experiments to measure the communication...
This paper describes the design and implementation of a kernel for an OODBMS, namely the METU Object-Oriented DBMS (MOOD). MOOD is developed on the Exodus Storage Manager (ESM). MOOD kernel provides the optimization and interpretation of SQL statements, dynamic linking of functions, and catalog management. SQL statements are interpreted whereas functions (which have been previously compiled with C++)...
The spareC++, an object-oriented database programming language, is an extension of C++ designed for writing applications on object-oriented databases. Since programmers can define and manipulate objects uniformly irrespective of their persistent states and of whether or not they are resident in virtual memory, spareC++ alleviates the impedance mismatch. In addition this language supports automatic...
Prototyping based on formal specification should satisfy the requirements of engineers and users equally. The support of both groups requires a formalization of all activities as contract base and an increase of experience by experimental strategies. Contrary to these requirements several problems rest with existing software development environments, which result in complex systems becoming easily...
The work presented in this research paper concentrates on the issues of determining the ideal way of schema integration and knowledge organization to support interoperation in multidatabase systems (MDBSs).
Data Base Management Systems (DBMS) were the catalyst for the myriad of database applications that exist today. The advantages gained through their introduction can clearly not be overstated. Further the use of database languages such as SQL allow for simple and efficient interaction with such systems. However, when embedded into dedicated application code the development costs involved, for many...
In recent years, library systems have evolved from simple electronic catalogues to extensive document sources. Progress in storage media, database and wide area networking technologies allow access to documents in their original form. Besides “modern” documents, which are often created and distributed in electronic exchange formats, huge amounts of ancient, paper based literature which are valuable...
In this paper we present OASIS 2.1, the last version of OASIS. OASIS is a formal, OO Specification Language developed in DSIC ([1] [4] [6] [8] [7] [12] [11]). In its initial versions, the Software Development Environment associated to the Language was formalized using first order theories that evolve over time. This lead us to a Logic Programming environment with the complement of a for dealing with...
We discuss the design and implementation of the O2 Views object-oriented database view mechanism, which allows the redefinition of both the structure and the behavior of objects stored in a database. The data model extended with views is given and the functionalities of the prototype implementing it are presented. The paper focuses on the requirements for the implementation of an object-oriented view...
In this paper an original query language, based only on the pictorial representation of a query is proposed. The database on which the queries are formulated is an object-oriented geographic information system already implemented. The definition of the data structure, of the operators and of the relationships between two geographic entities are given, and the definition of the visual o-o query language...
The paper describes a concept and facilities of the VIEW Classroom, a distance education system supporting interactions between a teacher and students. In a classroom a basic interaction between them is performed by questions and answers. In distributed education systems such an one-to-many interaction frequently implies difficulties in selecting by a teacher essential questions, and causes overload...
In this paper we describe how some well-known deficiencies of managerial decision making models can be overcome by combining previous work of Zebda [Zebda 1984] and de Korvin [de Korvin et al. 1995] with Keynes's conventional coefficient c which has recently been revived by Brady [Brady 1994], Furthermore, in this paper we will show how the described approach can be applied to the standard problem...
We describe a software technology that is “people oriented”, in the sense that it allows us to: specify a task as English syllogisms, together with tables of facts, run the specification consisting of English syllogisms directly, ask questions in English, get hypertexted English explanations of answers, automatically fill in business forms, and ...
The design of ESQL queries Optimizer may be decomposed into three dimensions: (i) the search space which defines the syntactic representation of all relevant aspects of an execution, (ii) the search strategy used to generate an optimal execution plan and (iii) the cost evaluator which calculates the metrics used by the search strategies. In this paper, we investigate issues involved in designing and...
Effective exploitation of shared-nothing multiprocessors to improve the performance of spatial database applications requires novel query processing techniques. This is because, unlike traditional data, spatial objects are naturally multidimensional. As such, traditional single-dimensional declustering strategies are not directly applicable for spatial relation. In this paper, we propose and study...
Object-oriented databases integrated into a C++ software engineering environment promise an appealing platform for managing complex data and engineering tasks. In competitive markets like CAD for civil engineering and architecture stringent reliability and performance criteria must be met before entering into commercial products. We present a benchmark study specifically tailored to such CAD domains...
An object oriented methodology for building a high level abstraction of a legacy database application is described. The methodology combines two different paradigms of software engineering: classical forward with reverse engineering. The structural part of a given system is determined by reverse engineering, while the functional and behavioural views on the application are developed by using classical...
It is widely acknowledged that good object clustering is critical to the performance of object-oriented databases. However, object clustering always involves some kind of overhead for the system. The aim of this paper is to propose a modelling methodology in order to evaluate the performances of different clustering policies. This methodology has been used to compare the performances of three clustering...
To develop an algorithm for any application takes thought and a lot of trial and error. The algorithm must be coded, compiled, tested for compliance with the specification. If it does not perform to target, the code must be amended, recompiled and tested again. The process is cyclic and time consuming. In this paper a novel method is introduced which allows the building or tuning of algorithms or programs at run-time by using an active database. The paper uses the domain of robotic vision as a case study to introduce the concept, particularly the first stage of the object recognition process known as...
A technique for spatial reasoning is described which is directly compatible with the data representation techniques used by Geographical Information Systems (GIS). GIS may be thought of as specialised forms of database systems which are distinguished by their ability to handle spatial data and are widely used to aid environmental planners to make decisions and predictions. However, their application...
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