Petri nets were proposed as a formal tool for modeling system behavior at the conceptual schema level by several authors. The paper describes and discusses some typical approaches. In the discussion, two aspects are considered: (1) the fulfillment of the requirements to a conceptual schema modeling approach and (2) the integration of static and dynamic properties.

With the increasing amount and diversity of information available on the Internet, there has been a huge growth in information systems that need to integrate data from distributed, heterogeneous data sources. Automed (Automatic Generation of Mediator Tools for Heterogeneous database Integration) is a database transformation and integration system, which is designed to support virtual and materi...

The initial assumption is that a database schema is produced by the integration of simultaneously and independently designed subschemas. The notion of a subschema is defined using the concepts of the relational data model, according to the appropriate external schema, which is used to express a user view onto a future database, on the conceptual level. The process of simultaneous design of subs...

We present ALA, a tool for the automatic lexical annotation (i.e. annotation w.r.t. a thesaurus/lexical resource) of structured and semi-structured data sources and the discovery of probabilistic lexical relationships in a data integration environment. ALA performs automatic lexical annotation through the use of probabilistic annotations, i.e. an annotation is associated to a probability value....

This paper presents current research trends and ongoing challenges in data warehouse design methods. In secondary data use context, traditional data warehouse design methods don’t address many of today’s challenges; particularly in the healthcare domain were semantics plays an essential role to achieve an effective and implementable heterogeneous data integration while satisfying core requireme...

Information integration is the problem of providing a unified and transparent view to a collection of data stored in multiple, autonomous and heterogeneous data sources. In this study we are focusing only on the inter organization information integration (web), as to different web sources has different data base management systems for the data management and different DBMS’s has their own synta...

Schema mapping is an important approach to solve the problem of data integration. This paper introduces a research prototype called SDE, which is a system for managing and facilitating the complex tasks of heterogeneous data transformation and integration. We also present a data transformation method based on schema mapping techniques. By analyzing the mappings and schemas it can automatically ...

Data integration systems provide access to a set of heterogeneous, autonomous data sources through a so-called global, or mediated view. There is a general consensus that the best way to describe the global view is through a conceptual data model, and that there are basically two approaches for designing a data integration system. In the global-as-view approach, one defines the concepts in the ...

Information integration is the problem of combining the data residing at different, heterogeneous sources, and providing the user with a unified view of these data, called mediated schema. The mediated schema is therefore a reconciled view of the information, which can be queried by the user. It is the task of the system to free the user from the knowledge on where data are, and how data are st...