Integration of data from autonomous, distributed and heterogeneous data sources poses several technical challenges. this paper overviews the data integration system AMOS II based on the wrapper-mediator approach. AMOS...
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Integration of data from autonomous, distributed and heterogeneous data sources poses several technical challenges. this paper overviews the data integration system AMOS II based on the wrapper-mediator approach. AMOS II consists of. (i) a mediator database engine that can process and execute queries over data stored locally and in several external data sources, and (ii) object-oriented (OO) multi-database views for reconciliation of data and schema heterogeneities among sources with various capabilities. the data stored in different types of data sources is translated and integrated using OO mediation primitives, providing the user with a consistent view of the data in all the sources. through its multi-database facilities many distributed AMOS II systems can interoperate in a federation. Since most data reside in the data sources, and to achieve high performance, the core of the system is a main-memory DBMS having a storage manager, query optimizer, transactions, client-server interface, disk backup, etc. the AMOS II data manager is optimized for main-memory access and is extensible so that new data types and query operators can be added or implemented in some external programming language. the extensibility is essential for providing seamless access to a variety of data sources. Copyright (C) 2001 John Wiley & Sons, Ltd.
this report summarizes the presentations, discussions and outcomes of the ecoop'99 Workshop on object Interoperability, held in Lisbon on Monday, June 14, 1999. Divided into four main sessions, the workshop covere...
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the continuous demand for software of ever-increasing complexity will change our current approach to software development. In the future, the creation of software will apply increasing levels of automation to the deve...
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ISBN:
(纸本)354066954X
the continuous demand for software of ever-increasing complexity will change our current approach to software development. In the future, the creation of software will apply increasing levels of automation to the development process. the application of componentware will become commonplace and development will move from the back office to the application user's workstation. All of these developments point to an essential increase in the many forms of software reuse. this panel brought together experts in,object technology and reuse to explore issues relating to object technology and the impact it has on systematic software reuse.
the PhDOOS workshop covered a wide scope, as its over 20 participants were PhD students in all areas of object orientation. the presentations covered topics such as databases, languages, software engineering and artif...
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ISBN:
(纸本)354066954X
the PhDOOS workshop covered a wide scope, as its over 20 participants were PhD students in all areas of object orientation. the presentations covered topics such as databases, languages, software engineering and artificial intelligence, components and generative progamming, analysis and design, frameworks and patterns, aspected orientedprogramming, distribution, and middleware. Several topics of shared interest were identified and targeted in separate discussion groups on meta-information, the success or failure of OODBMS, and a general theme on the future of object orientation. As the participants had various research interests covering practically all the OO spectrum, we can confidently state that these topics reflect actually the concerns and needs of the OO community, and emerge from its concrete needs. this document is to be complemented by a workshop proceedings document which will publish the full versions of the presented papers.
this paper presents a model for the representation and retrieval of structured documents considering their temporal properties. the purpose of this model is to serve as a platform for the development of digital librar...
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this paper presents a model for the representation and retrieval of structured documents considering their temporal properties. the purpose of this model is to serve as a platform for the development of digital library applications. thus, it consists of both a new data model and a query language that are specially adapted to the requirements of these applications. the main elements of the data model are a flexible type system for structured documents, and two temporal dimensions that represent the temporal properties of documents and the evolution of the database schema. As for its query language, it allows the retrieval of documents by specifying conditions on their structure, contents and temporal properties. this query language has been designed for exploiting the temporal information stored into a large digital library, making possible to relate document contents in time, as well as to analyse the evolution of topics. the paper also includes some guidelines for the efficient implementation of databases of structured documents by adopting the proposed data and query models. Copyright (C) 2001 John Wiley & Sons, Ltd.
this full-day workshop was organized in four sessions. the first three were thematic technical sessions dedicated to the presentation of the recent research results of participants. Seven, out of eleven accepted submi...
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Generic types in programming languages are most often supported with various forms of parametric polymorphism, i.e. functions on types. Within the framework of object-oriented languages, virtual types present an alter...
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there is considerable interest in programs that can migrate from one host to another and execute, Mobile programs are appealing because they support efficient utilization of network resources and extensibility of info...
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there is considerable interest in programs that can migrate from one host to another and execute, Mobile programs are appealing because they support efficient utilization of network resources and extensibility of information servers. However, since they cross administrative domains, they have the ability to access and possibly misuse a host's protected resources. In this paper, we present a novel approach for controlling and protecting a site's resources. In this approach, a site uses a declarative policy language to specify a set of constraints on accesses to resources, A set of code transformation tools enforces these constraints on mobile programs by integrating the access constraint checking code directly into the mobile program and resource definitions, Using this approach, a site does not need to explicitly include calls to reference monitors in order to protect resources. the performance analysis show that the approach performs better than reference monitor-based approaches in many cases. Copyright (C) 2000 John Wiley & Sons, Ltd.
Automatic program specialization can derive efficient implementations from generic components, thus reconciling the often opposing goals of genericity and efficiency. this technique has proved useful within the domain...
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the ecoop workshop on Mobile object Systems was first organized in 1995 and has been held every year since. the first two episodes in the series - entitled “objects and Agents” (1995) and “Agents on the Move” (199...
ISBN:
(纸本)3540415130
the ecoop workshop on Mobile object Systems was first organized in 1995 and has been held every year since. the first two episodes in the series - entitled “objects and Agents” (1995) and “Agents on the Move” (1996) - were exploratory in nature, reflecting a growing awareness and interest in the possibilities of mobile code and mobile objects for Internet programming. Towards the end of the 1990s, Interest in the domain began to stabilize and several mobile object systems appeared in the research community. As a consequence, further editions of the Mobile object Systems workshop concentrated on specific aspects of mobile objects. thus, the title of the 1997 workshop was “Operating System Support”, the theme of the 1998 workshop was “Security”, and the theme of the 1999 installment was “programming Language Support”.
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