Sökning: "Frank Drewes"

Visar resultat 1 - 5 av 10 avhandlingar innehållade orden Frank Drewes.

1. 1. Complexities of Order-Related Formal Language Extensions

   Författare :Martin Berglund; Frank Drewes; Henrik Björklund; Markus Holzer; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; complexity; automata; languages; order; shuffle; regular expressions; context-free; mildly context-sensitive; parsing; membership; algorithm analysis; Computer Science; datalogi;

   Sammanfattning : The work presented in this thesis discusses various formal language formalisms that extend classical formalisms like regular expressions and context-free grammars with additional abilities, most relating to order. This is done while focusing on the impact these extensions have on the efficiency of parsing the languages generated. LÄS MER

3. 2. Complexities of Parsing in the Presence of Reordering

   Författare :Martin Berglund; Frank Drewes; Bruce Watson; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; parsing; membership problems; complexity theory; reordering; shuffle; mildly context-sensitive; formal languages; Computer Science; datalogi;

   Sammanfattning : The work presented in this thesis discusses various formalisms for representing the addition of order-controlling and order-relaxing mechanisms to existing formal language models. An immediate example is shuffle expressions, which can represent not only all regular languages (a regular expression is a shuffle expression), but also features additional operations that generate arbitrary interleavings of its argument strings. LÄS MER

4. 3. Complexity and expressiveness for formal structures in Natural Language Processing

   Författare :Petter Ericson; Henrik Björklund; Frank Drewes; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; graph grammars; formal languages; natural language processing; parameterized complexity; abstract meaning representation; tree automata; deterministic tree-walking transducers; mildly context-sensitive languages; hyperedge replacement; tree adjoining languages; minimally adequate teacher;

   Sammanfattning : The formalized and algorithmic study of human language within the field of Natural Language Processing (NLP) has motivated much theoretical work in the related field of formal languages, in particular the subfields of grammar and automata theory. Motivated and informed by NLP, the papers in this thesis explore the connections between expressibility – that is, the ability for a formal system to define complex sets of objects – and algorithmic complexity – that is, the varying amount of effort required to analyse and utilise such systems. LÄS MER

5. 4. Order-preserving graph grammars

   Författare :Petter Ericson; Henrik Björklund; Frank Drewes; Sebastian Maneth; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Graph grammars; graph parsing; graph series; hyperedge replacement; uniform parsing problem; abstract meaning representation; semantic modelling; order preservation; reentrancy preservation; minimally adequate teacher; weighted graph grammars;

   Sammanfattning : The field of semantic modelling concerns formal models for semantics, that is, formal structures for the computational and algorithmic processing of meaning. This thesis concerns formal graph languages motivated by this field. LÄS MER

7. 5. Deep learning for news topic identification in limited supervision and unsupervised settings

   Författare :Arezoo Hatefi; Frank Drewes; Johanna Björklund; Xuan-Son Vu; Eric Gaussier; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Topic Identification; Data Clustering; News Stream Clustering; Semi-Supervised Learning; Unsupervised Learning; Event Topics; News Stories; Multimodal News; Document Classification; Document Clustering; Deep Learning; Deep Clustering; Pre-trained Language Models;

   Sammanfattning : In today's world, following news is crucial for decision-making and staying informed. With the growing volume of daily news, automated processing is essential for timely insights and in aiding individuals and corporations in navigating the complexities of the information society. LÄS MER