1,312 research outputs found
Towards a query language for annotation graphs
The multidimensional, heterogeneous, and temporal nature of speech databases
raises interesting challenges for representation and query. Recently,
annotation graphs have been proposed as a general-purpose representational
framework for speech databases. Typical queries on annotation graphs require
path expressions similar to those used in semistructured query languages.
However, the underlying model is rather different from the customary graph
models for semistructured data: the graph is acyclic and unrooted, and both
temporal and inclusion relationships are important. We develop a query language
and describe optimization techniques for an underlying relational
representation.Comment: 8 pages, 10 figure
Data Structures and Data Types in Object-Oriented Databases
The possibility of finding a static type system for object-oriented programming languages was initiated by Cardelli [Car88, CW85] who showed that it is possible to express the polymorphic nature of functions such a
Constraints for Semistructured Data and XML
Integrity constraints play a fundamental role in database design. We review initial work on the expression of integrity constraints for semistructured data and XML
A Basis for Interactive Schema Merging
We present a technique for merging the schemas of heterogeneous databases that generalizes to several different data models, and show how it can be used in an interactive program that merges Entity-Relationship diagrams. Given a collection of schemas to be merged, the user asserts the correspondence between entities and relationships in the various schemas by defining "isa" relations between them. These assertions are then considered to be elementary schemas, and are combined with the elementary schemas in the merge. Since the method defines the merge to be the join in an information ordering on schemas, it is a commutative and associative operation, which means that the merge is defined independent of the order in which schemas are presented. We briefly describe a prototype interactive schema merging tool that has been built on these principles. Keywords: schemas, merging, semantic data models, entity-relationship data models, inheritance 1 Introduction Schema merging is the proble..
The Fast Fourier Transforms as a Database Query
By casting the discrete Fourier transform in comprehension syntax and adding some primitives for array comprehensions , the fast Fourier transform may be derived by direct manipulation of source code
An ion resonance instability in grossly non-neutral plasmas
Ion resonance instability in grossly non-neutral plasma
Typing rule-based transformations over topological collections
Pattern-matching programming is an example of a rule-based programming style
developed in functional languages. This programming style is intensively used
in dialects of ML but is restricted to algebraic data-types. This restriction
limits the field of application. However, as shown by Giavitto and Michel at
RULE'02, case-based function definitions can be extended to more general data
structures called topological collections. We show in this paper that this
extension retains the benefits of the typed discipline of the functional
languages. More precisely, we show that topological collections and the
rule-based definition of functions associated with them fit in a polytypic
extension of mini-ML where type inference is still possible
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