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Lexikálně-sémantické konverze ve valenčním slovníku / Lexical-semantic Conversions in the Valency LexiconKettnerová, Václava January 2012 (has links)
In this thesis, we provide an adequate lexicographic representation of lexical-semantic conversion. Under the term lexical-semantic conversion, the relation between semantically similar syntactic structures which are based on separate lexical units of the same verb lexeme is understood. These relations are associated with various changes in valency structure of verbs - they may involve a number of valency complementations, their type, obligatoriness as well as morphemic forms. These changes arise from differences in the mapping of situational participants onto valency complementations. On the basis of semantic and syntactic analysis of two types of Czech lexical- semantic conversions, the locative conversion and the conversion Bearer of action-Location, we propose to represent lexical units creating syntactic variants in the relation of lexical semantic conversion by separate valency frames stored in the data component of the lexicon. The special attribute -conv whose value is a type of lexical-semantic conversion is assigned to relevant valency frames. Then the rule component of the lexicon consists of general rules determining changes in the correspondence between situational participants and valency complementations. This proposal is primarily designed for the valency lexicon of Czech verbs, VALLEX....
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Towards deep content extraction from specialized discourse : the case of verbal relations in patent claimsFerraro, Gabriela 20 July 2012 (has links)
This thesis addresses the problem of the development of Natural Language
Processing techniques for the extraction and generalization of compositional
and functional relations from specialized written texts and, in particular, from
patent claims. One of the most demanding tasks tackled in the thesis is,
according to the state of the art, the semantic generalization of linguistic
denominations of relations between object components and processes
described in the texts. These denominations are usually verbal expressions or
nominalizations that are too concrete to be used as standard labels in
knowledge representation forms -as, for example, “A leads to B”, and “C
provokes D”, where “leads to” and “provokes” both express, in abstract
terms, a cause, such that in both cases “A CAUSE B” and “C CAUSE D”
would be more appropriate. A semantic generalization of the relations allows
us to achieve a higher degree of abstraction of the relationships between
objects and processes described in the claims and reduces their number to a
limited set that is oriented towards relations as commonly used in the generic
field of knowledge representation. / Esta tesis se centra en el del desarrollo de tecnologías del Procesamiento del
Lenguage Natural para la extracción y generalización de relaciones
encontradas en textos especializados; concretamente en las reivindicaciones
de patentes. Una de las tareas más demandadas de nuestro trabajo, desde el
punto vista del estado de la cuestión, es la generalización de las
denominaciones lingüísticas de las relaciones. Estas denominaciones,
usualmente verbos, son demasiado concretas para ser usadas como etiquetas
de relaciones en el contexto de la representación del conocimiento; por
ejemplo, “A lleva a B”, “B es el resultado de A” están mejor representadas
por “A causa B”. La generalización de relaciones permite reducir el n\'umero
de relaciones a un conjunto limitado, orientado al tipo de relaciones utilizadas
en el campo de la representación del conocimiento.
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Nitridonickelates: Preparation, Structure and PropertiesMehta, Akash 27 October 2005 (has links)
Low valent nickel (less than +1) complexes are rare in nature, however they are regularly encountered in nitridonickelate chemistry. Ternary alkaline earth nitridonickelates exhibit a variety of interesting crystal structures with respect to their covalently bonded nitridonickelate anionic framework. The coordination geometry of low valent nickel in these compounds presents a unique structural feature with nickel being in linear coordination by nitrogen atoms. The nitridonickelate frameworks of compounds investigated in this work are: Ba2[Ni3N2]: The first ternary alkaline earth nitridonickelates with 2D Ni-N anionic network. The formal oxidation state of Ni is +0.67. Ba2(Ba6N)[NiN]6: The structure is made of o1D helical Ni-N anionic chains. Also, the structural stability of this compound´s structure type was found to occur over a wide range of substitution of Ba by Ca and Sr; a max. of 70 percent Ba could be successfully replaced by Sr and Ca atoms retaining the same structure type. The formal oxidation state of Ni is +0.83. Ba[NiN] and the solid solution series Ba[CuxNi1-xN]: The structure is made of 1D zig-zag Ni-N chains. The solid-solution series is isostructural to Ba[NiN] at lower content of Cu while, at higher content it resembles Ba[CoN] structure type, however at very high Cu content it again transforms to Ba[NiN] structure type. The formal oxidation state of Ni is +1.0. Sr2[Ni(CN)N]: The structure consists of N-Ni-(CN) dumbbells. The compound is the first example of cyano-nitridonickelate. The formal oxidation state of Ni is 0. The handling of the ternary alkaline earth nitridonickelates in specific and also of the other nitridometalates in general suffers greatly due to their being air and moisture sensitive. This requires synthetic methods suitable for air and moisture sensitive samples and also the respective instrumental setup for the measurement of their physical properties under inert atmosphere. Up to now no comprehensive investigation of the physical properties of the ternary alkaline earth nitridonickelates has been made. In this work an emphasis was given to systematically investigate the physical properties of the ternary alkaline earth nitridonickelates and to understand their structure specific physical properties. The common features of the investigated ternary alkaline earth nitridonickelates are: 1. the low valency of nickel. 2. the linear coordination of Ni and octahedral coordination of N. During this investigation the low valent character of nickel was experimentally confirmed with the help of X-ray absorption spectroscopy and the interpretation of magnetic susceptibility data where the magnetic moments of the nickel atoms were always consistent with that of a low valent nickel species. The results obtained from the magnetic measurements and electrical conductivity shows that the alkaline earth nitridonickelates order antiferromagnetically at low temperatures and show temperature dependent metallic conductivity whereas the cyano-nitridonickelate Sr2[Ni(CN)N] does not order at low temperature, is paramagnetic, and exhibits semiconducting behaviour. This investigation has provided a better understanding of ternary alkaline earth nitridonickelates with respect to the different structure they exhibit and their associated physical properties. This work motivates to extend the investigations of the physical properties of other nitridometalates. These also exhibit different crystal structures with respect to their nitridometalate anionic framework and thus, structure specific physical properties are also to be expected.
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