Results 1 
3 of
3
A Probabilistic NF2 Relational Algebra for Integrated Information Retrieval and Database Systems
 In Proceedings of the 2nd World Conference on Integrated Design and Process Technology
, 1996
"... The integration of information retrieval (IR) and database systems requires a data model which allows for modelling documents as entities, representing uncertainty and vagueness and performing uncertain inference. For this purpose, we present a probabilistic data model based on relations in nonfirst ..."
Abstract

Cited by 10 (1 self)
 Add to MetaCart
The integration of information retrieval (IR) and database systems requires a data model which allows for modelling documents as entities, representing uncertainty and vagueness and performing uncertain inference. For this purpose, we present a probabilistic data model based on relations in nonfirst normalform (NF2). Here, tuples are assigned probabilistic weights giving the probability that a tuple belongs to a relation. Thus, the set of weighted index terms of a document are represented as a probabilistic subrelation. In a similar way, imprecise attribute values are modelled as a setvalued attribute. We redefine the relational operators for this type of relations such that the result of each operator is again a probabilistic NF2 relation, where the weight of a tuple gives the probability that this tuple belongs to the result. By ordering the tuples according to decreasing probabilities, the model yields a ranking of answers like in most IR models. This effect also can be used for ...
Integration Of Complex Objects And Transitive Relationships For Information Retrieval
"... In this paper we show that in advanced information retrieval (IR) applications capa bilities for data aggregation, transitive computation and NF 2 (nonfirst normal form) relational computation are often necessary at the same time. We demonstrate that complex objects are naturally modeled as NF ..."
Abstract

Cited by 3 (2 self)
 Add to MetaCart
In this paper we show that in advanced information retrieval (IR) applications capa bilities for data aggregation, transitive computation and NF 2 (nonfirst normal form) relational computation are often necessary at the same time. We demonstrate that complex objects are naturally modeled as NF 2 relations whereas structures like hi erarchical thesauri must be modeled for transitive computation. Transitive process ing cannot be supported by stmcturally static structures like NF 2 relations. We pres ent a truly declarative query interface, which integrates data aggregation, transitive computation and NF 2 relational computation. Thus the interface supports the re trieval and structural manipulation of complex objects (e.g., documents, and biblio graphic references), their retrieval through transitive relationships (e.g., thesauri, citations) and data aggregation based on their components (e.g., citation counts, author productivity). Most importantly, users can formulate queries on a high ab straction level without mastering actual programming or database techniques.
A UserOriented Interface for Generalized Informetric Analysis Based on Applying Advanced Data Modelling Techniques
 Journal of Documentation
, 2000
"... This article presents a novel useroriented interface for generalized informetric analysis and demonstrates how informertic calculations can easily and declaratively be specified through advanced data modeling techniques. The interface is declarative and at a high level. Therefore it is easy to u ..."
Abstract

Cited by 2 (1 self)
 Add to MetaCart
This article presents a novel useroriented interface for generalized informetric analysis and demonstrates how informertic calculations can easily and declaratively be specified through advanced data modeling techniques. The interface is declarative and at a high level. Therefore it is easy to use, flexible, and extensible. It enables endusers to per form basic informetric ad hoc calculations easily and often with much less effort than in the contemporary online retrieval systems. It also provides several fruitful generaliza tions of typical informetric measurements like impact factors. These are based on sub stituting traditional loci of analysis, for instance journals, by other object types, such as authors, organizations, or countries. In the interface, bibliographic data are modeled as complex objects (nonfirst normal form relations) and terminological and citation net works involving transitive relationships are modeled as binary relations for deductive processing. The interface is flexible, because it makes it trivial to switch focus between various object types for infermetric calculations, e.g. from authors to institutions.