Structural integration: Concepts and case study

When integrating the views of a large telecomunications application database at Bellcore, it was found that some pairs of view objects had significant structural similarities but differed semantically.⁺ This observation motivated the design of the structural integration methodology described in this article. Currently existing view and schema integration methodologies are based on semantic considerations. They allow integration only if two objects agree in their semantic and structural aspects. Structural integration permits the integration of objects even if they differ semantically. This article introduces structural integration for the case of full structural correspondence. We further develop an important special case, namely structural integration for classes with attribute partial correspondence. We use a subschema of the telecommunications application to demonstrate the applicability of structural integration to situations involving the complexities of real-world databases and applications. Algorithms for checking full structural correspondence of classes and databases are presented. Structural integration has several advantages, including the identification of shared common structures that are important for sharing of data and methods.This research has been supported partially by grants from the Center for Manufacturing Systems at New Jersey Institute of Technology and from Bellcore     

Structural schema integration with full and partial correspondence using the dual model

The integration of views and schemas is an important part of database design and evolution and permits the sharing of data across complex applications. The view and schema integration methodologies used to date are driven purely by semantic considerations, and allow integration of objects only if that is valid from both semantic and structural view points. We discuss a new integration method called structural integration that has the advantage of being able to integrate objects that have structural similarities, even if they differ semantically. This is possible by using the object-oriented Dual Model which allows separate representation of structure and semantics. Structural integration has several advantages, including the identification of shared common structures that is important for sharing of data and methods.     

THE LABORATORY TESTING OF ALUMINOUS REFRACTORIES1

Eight brands of high alumina refractories and two brands of fire clay refractories, which are used by the trade under conditions of service requiring resistance to the corrosive action of lime and cement clinker at high temperatures, were subjected to standard and modified laboratory tests for high grade refractories. Data obtained indicate the results which may be expected in the technical examination of this type of product.     

Microbial sulfate reduction at low pH in sediments of an acidic lake in Argentina

We measured sulfate reduction in the acidic (pH < or = 3) sediment of an Argentinean lake influenced by volcanism. Sulfate reduction rates of 2.04 mmol m(-2) d(-1) were determined with a 35SO4(2-) core injection method and confirmed by batch incubations and from H2S measurements in the sediment. H2S production stopped when iron reduction was stimulated by addition of ferric iron. The results suggest that sulfate reduction at pH values around 3 is possible and can probably be used in biotechnological strategies if competing microbial processes are inhibited and electron donors are highly available.