5 research outputs found
Hyperset Approach to Semi-structured Databases and the Experimental Implementation of the Query Language Delta
This thesis presents practical suggestions towards the implementation of the
hyperset approach to semi-structured databases and the associated query
language Delta. This work can be characterised as part of a top-down approach
to semi-structured databases, from theory to practice. The main original part
of this work consisted in implementation of the hyperset Delta query language
to semi-structured databases, including worked example queries. In fact, the
goal was to demonstrate the practical details of this approach and language.
The required development of an extended, practical version of the language
based on the existing theoretical version, and the corresponding operational
semantics. Here we present detailed description of the most essential steps of
the implementation. Another crucial problem for this approach was to
demonstrate how to deal in reality with the concept of the equality relation
between (hyper)sets, which is computationally realised by the bisimulation
relation. In fact, this expensive procedure, especially in the case of
distributed semi-structured data, required some additional theoretical
considerations and practical suggestions for efficient implementation. To this
end the 'local/global' strategy for computing the bisimulation relation over
distributed semi-structured data was developed and its efficiency was
experimentally confirmed.Comment: Technical Report (PhD thesis), University of Liverpool, Englan
Hyperset approach to semi-structured databases and the experimental implementation of the query language Delta
This thesis presents practical suggestions towards the implementation of the hyperset approach to semi-structured databases and the associated query language Delta. This work can be characterised as part of a top-down approach to semi-structured databases, from theory to practice. The main original part of this work consisted in implementation of the hyperset Delta query language to semi-structured databases, including worked example queries. In fact, the goal was to demonstrate the practical details of this approach and language. The required development of an extended, practical version of the language based on the existing theoretical version, and the corresponding operational semantics. Here we present detailed description of the most essential steps of the implementation. Another crucial problem for this approach was to demonstrate how to deal in reality with the concept of the equality relation between (hyper)sets, which is computationally realised by the bisimulation relation. In fact, this expensive procedure, especially in the case of distributed semi-structured data, required some additional theoretical considerations and practical suggestions for efficient implementation. To this end the 'local/global' strategy for computing the bisimulation relation over distributed semi-structured data was developed and its efficiency was experimentally confirmed. Finally, the XML-WDB format for representing any distributed WDB as system of set equations was developed so that arbitrary XML elements can participate and, hence, queried by the -language. The query system with the syntax of the language and several example queries from this thesis is available online at http://www.csc.liv.ac.uk/˜molyneux/t
Моделирование при исследовании технических систем: использование некоторых расширений теории графов
Practical necessity of the graph theory expansion is shown, in particular — for the modeling and technical systems investigation. Eshgraph term is suggested. It expands ―graph‖ term. Thus it expands graph theory. Examples of the eshgraph and geometric eshgraph usage are presentedПоказана практическая необходимость расширения теории графов, в частности — для моделирования и исследования технических систем. Введено понятие «эшграф», расширяющее понятие граф и, таким образом, расширяющее теорию графов. Приведены примеры использования эшграфа при моделировании ТС
Hyperset approach to semi-structured databases and the experimental implementation of the query language Delta
This thesis presents practical suggestions towards the implementation of the hyperset approach to semi-structured databases and the associated query language Delta. This work can be characterised as part of a top-down approach to semi-structured databases, from theory to practice. The main original part of this work consisted in implementation of the hyperset Delta query language to semi-structured databases, including worked example queries. In fact, the goal was to demonstrate the practical details of this approach and language. The required development of an extended, practical version of the language based on the existing theoretical version, and the corresponding operational semantics. Here we present detailed description of the most essential steps of the implementation. Another crucial problem for this approach was to demonstrate how to deal in reality with the concept of the equality relation between (hyper)sets, which is computationally realised by the bisimulation relation. In fact, this expensive procedure, especially in the case of distributed semi-structured data, required some additional theoretical considerations and practical suggestions for efficient implementation. To this end the 'local/global' strategy for computing the bisimulation relation over distributed semi-structured data was developed and its efficiency was experimentally confirmed. Finally, the XML-WDB format for representing any distributed WDB as system of set equations was developed so that arbitrary XML elements can participate and, hence, queried by the -language. The query system with the syntax of the language and several example queries from this thesis is available online at http://www.csc.liv.ac.uk/˜molyneux/t/EThOS - Electronic Theses Online ServiceGBUnited Kingdo