Numerical Solution for Polymer Transient Flows in a Circle Bounded Composite Formation

A new numerical model for transient flows of polymer solution in a circular bounded composite formation is presented in this paper. Typical curves of the wellbore transient pressure are yielded by FEM. The effects of non-Newtonian power-law index, mobility and boundary distance have been considered. It is found that for the mobility ratio larger than 1, which is favorable for the polymer flooding, the pressure derivative curve in log-log form rises up without any hollow. On the other hand, if the pressure derivative curve has a hollow and then is raised up, we say that the polymer flooding fails. Finally, the new model has been extended to more complicated boundary case.

Media translation and lesser-used languages: implications of subtitles for Irish language broadcastind

Eguíluz, Federico; Merino, Raquel; Olsen, Vickie; Pajares, Eterio; Santamaría, José Miguel (eds.)

First SPARK-STREAM Workshop on livelihoods and languages, Bangkok, Thailand, 9-11 April 2003. Livelihoods and languages: a SPARK-STREAM learning and communications process

The First SPARK-STREAM Workshop on Livelihoods and Languages took place in Bangkok, Thailand, from 9-11 April 2003. It was the first activity in a SPARK-STREAM learning and communications process around livelihoods and languages. (PDF contains 53 pages)

Second SPARK-STREAM Workshop on livelihoods and languages

The Second SPARK-STREAM Workshop on Livelihoods and Languages took place in Tagaytay City, Philippines, from 12-14 June 2003. Outputs were intended to be: Drafts of language-specific “Guide to Learning and Communicating about Livelihoods”. Drafts of articles for STREAM Journal and SPARK Newsletter. Priorities and practical follow-up for capacity-building in carrying out participatory livelihoods analysis Follow-up plans. [PDF contains 30 pages]

On Bounded Strictly Positive Operators of Closed Range and Some Applications to Asymptotic Hyperstability of Dynamic Systems

The problem discussed is the stability of two input-output feedforward and feedback relations, under an integral-type constraint defining an admissible class of feedback controllers. Sufficiency-type conditions are given for the positive, bounded and of closed range feed-forward operator to be strictly positive and then boundedly invertible, with its existing inverse being also a strictly positive operator. The general formalism is first established and the linked to properties of some typical contractive and pseudocontractive mappings while some real-world applications and links of the above formalism to asymptotic hyperstability of dynamic systems are discussed later on.

Efficient learning of decomposable models with a bounded clique size

The learning of probability distributions from data is a ubiquitous problem in the fields of Statistics and Artificial Intelligence. During the last decades several learning algorithms have been proposed to learn probability distributions based on decomposable models due to their advantageous theoretical properties. Some of these algorithms can be used to search for a maximum likelihood decomposable model with a given maximum clique size, k, which controls the complexity of the model. Unfortunately, the problem of learning a maximum likelihood decomposable model given a maximum clique size is NP-hard for k > 2. In this work, we propose a family of algorithms which approximates this problem with a computational complexity of O(k · n^2 log n) in the worst case, where n is the number of implied random variables. The structures of the decomposable models that solve the maximum likelihood problem are called maximal k-order decomposable graphs. Our proposals, called fractal trees, construct a sequence of maximal i-order decomposable graphs, for i = 2, ..., k, in k − 1 steps. At each step, the algorithms follow a divide-and-conquer strategy based on the particular features of this type of structures. Additionally, we propose a prune-and-graft procedure which transforms a maximal k-order decomposable graph into another one, increasing its likelihood. We have implemented two particular fractal tree algorithms called parallel fractal tree and sequential fractal tree. These algorithms can be considered a natural extension of Chow and Liu’s algorithm, from k = 2 to arbitrary values of k. Both algorithms have been compared against other efficient approaches in artificial and real domains, and they have shown a competitive behavior to deal with the maximum likelihood problem. Due to their low computational complexity they are especially recommended to deal with high dimensional domains.

Processing Facilitation Strategies in OV and VO Languages: A Corpus Study

The present corpus study aimed to examine whether Basque (OV) resorts more often than Spanish (VO) to certain grammatical operations, in order to minimi ze the number of arguments to be processed before the verb. Ueno & Polinsky (2009) argue that VO/OV languages use certain grammatical resources with different frequencies in order to facilitate real-time processing. They observe that both OV and VO languages in their sample (Japanese, Turkish and Spanish) have a similar frequency of use of subject pro-drop; however, they find that OV languages (Japanese, Turkish) use more intransitive sentences than VO languages (English, Spanish), and conclude this is an OV-specific strategy to facilitate processing. We conducted a comparative corpus study of Spanish (VO) and Basque (OV). Results show (a) that the fre- quency of use of subject pro-drop is higher in Basque than in Spanish; and (b) Basque does not use more intransitive sentences than Spanish; both languages have a similar frequency of intransitive sentences. Based on these findings, we conclude that the frequency of use of grammatical resources to facilitate the processing does not depend on a single typological trait (VO/OV) but it is modulated by the concurrence of other grammatical feature.

Resonance cones and mode conversion in a warm magnetized bounded plasma

The warm plasma resonance cone structure of the quasistatic field produced by a gap source in a bounded magnetized slab plasma is determined theoretically. This is initially determined for a homogeneous or mildly inhomogeneous plasma with source frequency lying between the lower hybrid frequency and the plasma frequency. It is then extended to the complicated case of an inhomogeneous plasma with two internal lower hybrid layers present, which is of interest to radio frequency heating of plasmas.

In the first case, the potential is obtained as a sum of multiply reflected warm plasma resonance cones, each of which has a similar structure, but a different size, amplitude, and position. An important interference between nearby multiply-reflected resonance cones is found. The cones are seen to spread out as they move away from the source, so that this interference increases and the individual resonance cones become obscured far away from the source.

In the second case, the potential is found to be expressible as a sum of multiply-reflected, multiply-tunnelled, and mode converted resonance cones, each of which has a unique but similar structure. The effects of both collisional and collisionless damping are included and their effects on the decay of the cone structure studied. Various properties of the cones such as how they move into and out of the hybrid layers, through the evanescent region, and transform at the hybrid layers are determined. It is found that cones can tunnel through the evanescent layer if the layer is thin, and the effect of the thin evanescent layer is to subdue the secondary maxima of cone relative to the main peak, while slightly broadening the main peak and shifting it closer to the cold plasma cone line.

Energy theorems for quasistatic fields are developed and applied to determine the power flow and absorption along the individual cones. This reveals the points of concentration of the flow and the various absorption mechanisms.

Formal languages, part theory, and change

A general definition of interpreted formal language is presented. The notion “is a part of" is formally developed and models of the resulting part theory are used as universes of discourse of the formal languages. It is shown that certain Boolean algebras are models of part theory.

With this development, the structure imposed upon the universe of discourse by a formal language is characterized by a group of automorphisms of the model of part theory. If the model of part theory is thought of as a static world, the automorphisms become the changes which take place in the world. Using this formalism, we discuss a notion of abstraction and the concept of definability. A Galois connection between the groups characterizing formal languages and a language-like closure over the groups is determined.

It is shown that a set theory can be developed within models of part theory such that certain strong formal languages can be said to determine their own set theory. This development is such that for a given formal language whose universe of discourse is a model of part theory, a set theory can be imbedded as a submodel of part theory so that the formal language has parts which are sets as its discursive entities.

THE AINU LANGUAGES: TRADITIONAL RECONSTRUCTION, EURASIAN AREAL LINGUISTICS, AND DIACHRONIC (HOLISTIC) TYPOLOGY

El objetivo principal de esta tesis doctoral es, en primer lugar, ofrecer una reconstrucción alternativa del protoainu para, en segundo lugar, aplicar conceptos de tipología diacrónicaholística con el fin de discernir algún patrón evolutivo que ayude a responder a la pregunta:¿por qué la lengua ainu es como es en su contexto geolingüístico (lengua AOV con prefijos),cuando en la región euroasiática lo normal es encontrar el perfil 'lengua AOV con sufijos'? En suma, se trata de explorar las posibilidades que ofrece la tipología diacrónica holística,combinada con métodos más tradicionales, en la investigación de las etapas prehistóricas delenguas aisladas, es decir, sin parientes conocidos, como el ainu, el vasco, el zuñi o elburushaski. Este trabajo se divide en tres grandes bloques con un total de ocho capítulos, unapéndice con las nuevas reconstrucciones protoainúes y la bibliografía.El primer bloque se abre con el capítulo 1, donde se hace una breve presentación delas lenguas ainus y su filología. El capítulo 2 está dedicado a la reconstrucción de la fonologíaprotoainu. La reconstrucción pionera pertenece a A. Vovin (1992), que de hecho sirve comobase sobre la que ampliar, corregir o modificar nuevos elementos. En el capítulo 3 se describela morfología histórica de las lenguas ainus. En el capítulo 4 se investiga esta opción dentrode un marco más amplio que tiene como objetivo analizar los patrones elementales deformación de palabras. El capítulo 5, con el que se inicia el segundo bloque, da cabida a lapresentación de una hipótesis tipológica diacrónica, a cargo de P. Donegan y D. Stampe, conla que especialistas en lenguas munda y mon-khmer han sido capaces de alcanzar unreconstrucción del protoaustroasiático según la cual el tipo aglutinante de las lenguas mundasería secundario, frente al original monosilábico de las lenguas mon-khmer. En el capítulo 6se retoma la perspectiva tradicional de la lingüística geográfica, pero no se olvidan algunas delas consideraciones tipológicas apuntadas en el capítulo anterior (el hecho de que la hipótesisde Donegan y Stampe no funcione con el ainu no significa que la tipología diacrónica nopueda ser todavía de utilidad). En el capítulo 7 se presentan algunas incongruencias queresultan tras combinar las supuestas evidencias arqueológicas con el escenario lingüísticodescrito en capítulos anteriores. Las conclusiones generales se presentan en el capítulo 8. Elapéndice es una tabla comparativa con las dos reconstrucciones disponibles a fecha de hoypara la lengua protoainu, es decir, las propuestas por A. Vovin en su estudio seminal de 1992y en el capítulo 3 de la presente tesis. Dicha tabla incluye 686 reconstrucciones (puedehacerse una sencilla referencia cruzada con Vovin, puesto que ambas están ordenadasalfabéticamente).