Automaták, fák és logika = Automata, trees and logic

Elemi idejű exponenciális algoritmus adtunk meg reguláris szavak ekvivalenciájának eldönthetőségére. Általánosítottuk Kleene tételét végtelen szavakat is felismerő súlyozott automatákra. Kifejlesztettünk egy algebrai módszert, amellyel a CTL logika számos szegmense estén eldönthető, hogy egy reguláris fanyelv definiálható-e a szegmensben. Vizsgáltuk a faautomaták algebrai tulajdonságait, megadtuk a felismerhetőség egy algebrai jellemzését. Definiáltunk a multi-leszálló fatranszformátort és megmutattuk, hogy ekvivalens a determinisztikus reguláris szűkítésű felszálló fatranszformátorral. Meghatároztuk a lineáris multi-leszálló osztály számítási erejét. Megmutattuk, hogy az alakmegőrző leszálló fatranszformátorok ekvivalensek az átcímkézőkkel és bebizonyítottuk, hogy az alakmegőrző tulajdonság eldönthető. Megadtuk a kavics makró fatranszformációk egy felbontását és megmutattuk, hogy a különböző cirkularitási tulajdonságok eldönthetők. Ugyancsak megadtuk a felbontást erős kavics kezelés estén is. Általánosítottuk J. Engelfriet hiararchia tételét súlyozott fatranszformátorokra. Súlyozott faautomatákra definiáltuk a termátíró szemantikát és megmutattuk, hogy ekvivalens az algebari szenmatikával. Algoritmust adtunk annak eldöntésére, hogy egy polinomiálisan súlyozott faautomata véges költségű-e. Vizsgáltuk a súlyozott faautomata különböző változatait: fuzzy faautomata, multioperátor monoid feletti faautomata, Ez utóbbi esetre általánosítottuk a Kleene tételt. | We gave an elementary algorithm for deciding the equivalence of regular words. We generalized Kleene's theorem to weighted automata processing infinite words. We developed an algebraic method that, for several segments of the CTL logic, can be applied to decide if a regular tree language can be defined in that segment. We examined algebraic properties of tree automata, and gave an algebraic characterization of recognizability. We defined multi bottom-up tree transducers and showed that they are equivalent to top-down tree transducers with regular look-ahead. We determined the computation power of the linear subclass. We showed that shape preserving bottom-up tree transducers are equivalent to relabelings. We proved that the shape preserving property is decidable. We gave a decomposition for pebble macro tree transducers and showed that certain circularity properties are decidable. We also gave a decomposition for the strong pebble handling. We have generalized the hierarchy theorem of J. Engelfriet to weighted tree transducers. We defined the term rewrite semantics of weighted tree transducers and showed that it is equivalent to the algebraic semantics. We gave a decision algorithm for the finite cost property of a polynomially weighted tree automata. We defined different versions of weighted tree automata: fuzzy tree automata, weighted tree automata over a multioperator monoid. For the latter we generalized Kleene's theorem

Mechanical weathering in cold regions with special emphasis on the Antarctic environment and the freeze-thaw mechanism in particular.

Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 2003.Consideration of almost any geomorphology textbook will show the fundamental argument that in cold environments mechanical weathering processes, usually freeze-thaw, will predominate and that chemical weathering will be temperature-limited, often to the point of non occurrence. These basic concepts have underpinned geomorphology for over a century and are the basis for the development of many landforms in periglacial regions. With the introduction of data loggers so field data became more readily available but, sadly, those data were not of a quality to other than justify the existent assumptions and thus did little more than reinforce, rather than test, the nature of our understanding of cold region weathering. Factors such as rock properties were dealt with to a limited extent but rock moisture was all but ignored, despite its centrality to most weathering processes. Here the results of field studies into weathering in cold regions, coupled with laboratory experiments based on the field data, are presented. An attempt is made to overcome the shortcomings of earlier studies. Temperature, moisture and rock properties have all been considered. Processes were not assumed but rather the data were used to evaluate what processes were operative. The results, both in terms of weathering process understanding per se and of its application to landform development, significantly challenge our longheld perceptions. Information is presented that shows that it is not temperature, but rather water, that is the limiting factor in cold region weathering. Indeed, in the absence of water, many cold environments have attributes akin to a hot desert. The relevance of this is that weathering processes other than freeze-thaw may play a significant role and that in the presence of water chemical weathering can play a far greater role than hitherto thought. Overall, the whole concept of zonality with respect to weathering is questioned. Finally, the attributes of weathering are put within the context of landform development and questions raised regarding the origin of some forms and of their palaeoenvironmental significance. Attributes of periglacial, glacial and zoogeomorphic processes and landforms in present and past cold environments are also presented

The communicative theory of Terminology (CTT) applied to the development of a corpus-based specialised dictionary of the ceramics industry

Esta tesis es el resultado de un proyecto destinado a la creación de un diccionario activo, bilingüe (español-inglés; inglés-español) y especializado de la industria cerámica y azulejera con la Teoría Comunicativa de la Terminología como su pilar teórico principal. Debido al posicionamiento teórico adoptado, la investigación aquí presentada ha partido de un estudio de corpus (compilado ad hoc) en el que los términos han sido analizados in vivo y caracterizados de acuerdo al ¿habitat¿ en el que se hallan en el texto especializado. Así pues, la aproximación hecha al estudio de la terminología industrial cerámica hace pertinente el uso de la etiqueta ¿lexicografía especializada¿ a la hora de referirnos a un trabajo como éste en el que se ha tratado de ir más allá de la práctica terminográfica para dar lugar a un estudio en el que se prima el contexto, las asociaciones naturales de los términos (colocaciones) y la naturaleza comunicativa de la terminología. De este modo, en esta tesis se ha presentado de manera progresiva, además de un marco teórico detallado y coherente con el fin último de la investigación, la metodología utilizada para la elaboración del diccionario en curso, ampliamente basada en el uso de programas informáticos tanto para la explotación del corpus (WordSmith Tools 4.0), como para la creación de la base de datos terminológica (TermStar XV) y la generación de entradas finales (GENDIC).Así pues, esta tesis presenta de manera progresiva los resultados obtenidos en cada etapa del método de trabajo y 4,000 entradas finales (en este caso del inglés al español) correspondientes a las letras A, B, N, O, U y V del diccionario.This PhD dissertation is the result of an ongoing process aimed at the creation of a bilingual corpus-based specialised active dictionary of the ceramic industry, with the Communicative Theory of Terminology (CTT) as its mainstay. According to the grounding principles of the CTT, this research has departed form a corpus-based approach in which terms have been analysed in vivo and characterised from the natural habitat in which they are given in specialised communication/discourse. In this light, it has been put forward how the study of terms – made possible thanks to the activity of compiling and describing them, called terminography – may be complemented by the wider projection of specialised lexicography for the compilation and elaboration of LSP, user-oriented and user-friendly quality products in the form of dictionaries. This specialised lexicographical dimension of the work has necessarily implied the need to renew the concept of speciality language dictionaries applied to the ceramic industry and has given way to the creation of a (prospective) active dictionary in this field with a marked emphasis on context. Accordingly, the importance of pragmatic aspects in a work of this sort, has made it necessary to undertake an in-depth revision and analysis of the socio-economic context for the research in order be able to establish and solve the specific terminological needs that the ceramic industrial discourse community may find. On the basis of this theoretical framework, the method of study followed for the development of the prospective dictionary has comprised 8 broad stages: the stage of work preparation and corpus compilation, the elaboration of the field diagram, the stage of documentary corpus management, term extraction, data processing, revision and normalisation and finally, the edition stage. Two main types of results have been presented: those obtained through work in progress in the different stages of the method and final ones strictly speaking, that is, 4,000 English-Spanish entries in their final format (as they will appear in the prospective dictionary) belonging to the letters A, B, N, O, U and V of a complete dictionary which will include a total of 26,000 entries