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Grammars with Restricted Derivation Trees
Koutný, Jiří ; Janoušek, Jan (oponent) ; Vojnar, Tomáš (oponent) ; Meduna, Alexandr (vedoucí práce)
This doctoral thesis studies theoretical properties of grammars with restricted derivation trees. After presenting the state of the art concerning this investigation area, the research is focused on the three main kinds of the restrictions placed upon the derivation trees. First, it introduces completely new investigation area represented by cut-based restriction and examines the generative power of the grammars restricted in this way. Second, it investigates several new properties of path-based restriction placed upon the derivation trees. Specifically, it studies the impact of erasing productions on the generative power of grammars with restricted path and introduces two corresponding normal forms. Then, it describes a new relation between grammars with restricted path and some pseudoknots. Next, it presents a counterargument to the generative power of grammars with controlled path that has been considered as well-known so far. Finally, it introduces a generalization of path-based restriction to not just one but several paths. The model generalized in this way is studied, namely its pumping, closure, and parsing properties.
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Synchronous Formal Systems Based on Grammars and Transducers
Horáček, Petr ; Janoušek, Jan (oponent) ; Yamamura,, Akihito (oponent) ; Meduna, Alexandr (vedoucí práce)
This doctoral thesis studies synchronous formal systems based on grammars and transducers, investigating both theoretical properties and practical application perspectives. It introduces new concepts and definitions building upon the well-known principles of regulated rewriting and synchronization. An alternate approach to synchronization of context-free grammars is proposed, based on linked rules. This principle is extended to regulated grammars such as scattered context grammars and matrix grammars. Moreover, based on a similar principle, a new type of transducer called the rule-restricted transducer is introduced as a system consisting of a finite automaton and context-free grammar. New theoretical results regarding the generative and accepting power are presented. The last part of the thesis studies linguistically-oriented application perspectives, focusing on natural language translation. The main advantages of the new models are discussed and compared, using select case studies from Czech, English, and Japanese to illustrate.
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Grammars with Restricted Derivation Trees
Koutný, Jiří ; Janoušek, Jan (oponent) ; Vojnar, Tomáš (oponent) ; Meduna, Alexandr (vedoucí práce)
This doctoral thesis studies theoretical properties of grammars with restricted derivation trees. After presenting the state of the art concerning this investigation area, the research is focused on the three main kinds of the restrictions placed upon the derivation trees. First, it introduces completely new investigation area represented by cut-based restriction and examines the generative power of the grammars restricted in this way. Second, it investigates several new properties of path-based restriction placed upon the derivation trees. Specifically, it studies the impact of erasing productions on the generative power of grammars with restricted path and introduces two corresponding normal forms. Then, it describes a new relation between grammars with restricted path and some pseudoknots. Next, it presents a counterargument to the generative power of grammars with controlled path that has been considered as well-known so far. Finally, it introduces a generalization of path-based restriction to not just one but several paths. The model generalized in this way is studied, namely its pumping, closure, and parsing properties.
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Synchronous Formal Systems Based on Grammars and Transducers
Horáček, Petr ; Janoušek, Jan (oponent) ; Yamamura,, Akihito (oponent) ; Meduna, Alexandr (vedoucí práce)
This doctoral thesis studies synchronous formal systems based on grammars and transducers, investigating both theoretical properties and practical application perspectives. It introduces new concepts and definitions building upon the well-known principles of regulated rewriting and synchronization. An alternate approach to synchronization of context-free grammars is proposed, based on linked rules. This principle is extended to regulated grammars such as scattered context grammars and matrix grammars. Moreover, based on a similar principle, a new type of transducer called the rule-restricted transducer is introduced as a system consisting of a finite automaton and context-free grammar. New theoretical results regarding the generative and accepting power are presented. The last part of the thesis studies linguistically-oriented application perspectives, focusing on natural language translation. The main advantages of the new models are discussed and compared, using select case studies from Czech, English, and Japanese to illustrate.
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