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Promotion of agroforestry practices in sub-Sahara Africa may help sustain subsistent food and wood production by integrating trees and crops on farmlands to replenish soil fertility and improve crop yield. Using rotational woodlot and pigeonpea intercropping systems in semi-arid Tanzania as case studies, my research screened suitable tree species to increase fuelwood supply and examined mechanisms for reducing tree-crop competition. By adopting nutrient use efficiency (the ratio of biomass yield to nutrient uptake) as a criterion, I found that selecting tree species of low wood nutrient concentrations would minimize nutrient exports by 42 – 60 %, thus reducing soil nutrient depletion while concurrently sustaining local fuelwood supply harvested from rotational woodlots. Currently smallholder farmers cannot afford to replenish soil fertility because of high fertilizer costs. However, 5-year tree fallowing raised soil N and P levels for maize culture as high as those from recommended fertilizer applications. Post-fallow maize yield was also increased significantly over natural fallow practices. Apparently there is a trade-off between yields of maize and fuelwood under rotational woodlot culture providing farmers the choice to proportion tree and crop composition based on priority demands. An alternative practice of intercropping pigeonpea with maize may also rapidly replenish soil fertility as well as enhance maize yield when competitive interactions between trees and crops are controlled. Vector analysis revealed that such interactions suppressed biomass yields of maize and pigeonpea by 30 % and 60 %, respectively, due to limited soil nutrients and/or moisture. Optimizing yields of both crops would require prescribed fertilizer addition when intercropped, but dose rates can be lowered by half under the improved fallow system due to alleviating interspecific competition. My findings form the basis of a plea for greater use of rotational woodlot and pigeonpea intercropping systems in semi-arid areas. I conclude that smallholder farm management of rotational agroforestry systems can be significantly improved by refining tree selection criteria and mitigating nutrient competition between trees and crops to maintain food and fuelwood production.

Magistro baigiamajame darbe analizuojama lietuvių šnekos vizemų vizualizacijos problema, tiriami lietuvių kalbos vizemų vizualizacijos požymiai, galimybės koduoti SAMPA kodais analizė, analizuojami programinės įrangos kūrimo metodai ir algoritmai. Sukurtas algoritmas sprendžiantis lietuvių šnekos vizemų vizualizacijos problemą. Pasirinktas kompiuterinės grafikos tipas, tinkantis iškeltiems tikslams įvykdyti – vektorinė grafika. Sukurti du vektorių transformacijos metodai, išanalizuoti jų skirtumai ir praktinio panaudojimo galimybės. Sukurta programinė įranga įgalinanti vartotoją kurti vizemas, jas transformuoti ir derinti jų vaizdavimo trukmę įvairiais koeficientais ir vykdyti animaciją pagal pasirinktą transformacijos metodą. Sudarytos penkios vizemos ir dviejų lietuviškų žodžių animacijos, kurių pagalba atliktas tyrimas parodantis darbo ir metodų realizavimo kokybę bei pritaikomumą. / In this final Master's thesis work features of Lithuanian speech visemes visualization are analyzed. Possibility of coding with SAMPA codes, software methods and algorithms are inspected. Type of computer graphics is picked, which is suitable for software objectives – vector graphics. Two transformation methods for vector graphics are created and their differences and practical usability are analyzed. Software for visemes creation, transformation and tuning of their duration and duration of transformation between visemes is created and described. The main purpose of this software is to animate Lithuanian speech by the method selected. Five visemes for two Lithuanian words animation is created. Using these visemes research has been done which is showing the quality of realization and adaptability of this software.

The portion of energy converted by non-linear loads in the modern power system is increasing due to the energy-efficiency and sophistication possible with power electronics. Higher voltage and energy ratings are continuously forthcoming. These devices draw non-linear currents resulting in voltage waveform distortion at the Point of Common Coupling due to non-zero supply impedances between voltage source and the PCC. With the increase in waveform distortion comes the demand for better Quality of Supply management. The verification and quantification of the origin of waveform distortion in a power system is a continuous field of study and forms a critical part of the mitigation design. Methods utilizing single-point measurements, usually taken at the Point of Common Coupling, for the assessment of the harmonic distortion generated by loads are continuously being published. It’s been proven by means of computer simulations and laboratory experiments that in an interconnected network where multiple sources of distortion exist that loads have the ability to exchange harmonic active power between each other. This project investigates the latter statement by conducting practical experiments to conclude that loads have the ability to exchange harmonic active power and that multiple synchronized measurements should be taken to assess the harmonic distortion due to a load. Laboratory experiments are carried utilizing an acknowledged single point measurement method. The results are compared to the direction of harmonic active power obtained from utilizing multiple synchronized measurements. To further the information obtained from the laboratory experiments, practical experiments were conducted utilizing the same methods. The results obtained coincided with the results of previously conducted experiments of which the results were published. From the results obtained it was concluded that in an interconnected network where multiple sources of distortion exist that loads have the ability to exchange harmonic active power between each other. Furthermore it was proven that the single point measurement method investigated presented inconsistent results. Ultimately it was concluded that the reason for the inconsistency was due to the fact that loads have the ability to exchange harmonic active power and that the single point measurement failed to acknowledge this. / Thesis (M.Ing. (Electrical and Electronic Engineering))--North-West University, Potchefstroom Campus, 2012

The search potential of a Standard Model Higgs boson in the Vector Boson Fusion production mechanism with Higgs boson decaying to two leptons and two neutrinos via decay to two Z bosons with the ATLAS detector is investigated. The ATLAS detector is a general purpose detector in operation at CERN measuring proton-proton collisions produced by the Large Hadron Collider. This channel has been shown to have high sensitivity at large Higgs mass, where large amounts of missing energy in the signal provide good discrimination over expected backgrounds. This work takes a first look at whether the sensitivity of this channel may be improved using the remnants of the vector boson fusion process to pro- vide extra discrimination, particularly at lower mass where sensitivity of the main analysis is reduced because of lower missing energy. Simulated data samples at centre of mass energy 7 Te V are used to derive signal significances over the mass range between 200-600 Ge V / c2. Because of varying signal properties with mass, a low and a high mass event selection were developed and optimized. A comparison between simulated and real data (collected in 2010) is made of variables used in the analysis and the effect of pileup levels corresponding to those in the 2010 data is investigated. Possible methods to estimate some of the main backgrounds to this search are described and discussed. The impact • of important theoretical and detector related systematics are taken into account. Final results are presented in the form of 95 % Confidence Level exclusion limits on the signal cross section relative to the SM prediction as a function of Higgs boson mass, based on an integrated luminosity of 33.4 pb -1 of data collected during 2010.

This dissertation develops a semantic model of gradable adjectives such as ‘tall’, ‘good’, ‘big’, ‘heavy’, etc., within a formal semantic theory of locatives we call Locative Structure Semantics (LSS). Our central hypothesis is that gradable adjectives are, semantically, a species of locative expression. The view of gradable adjectives as locatives is inspired by the vector-based semantic models of Vector Space Semantics (VSS), as well as the notion of perspective or point of view, as found in Leonard Talmy’s research on spatial expressions (Talmy [153]) and the tradition of Situation Semantics (cf. Barwise and Perry [9, p. 39]). Following Barwise and Seligman [11], we construe the contextual variability that characterises gradable adjectives in terms of shifts in cognitive perspective. We argue that perspectives are a formal part of a semantic representational structure that is shared by expressions from several different domains, which we refer to as a locative structure (L-structure). The notion of an L-structure is influenced by Reichenbach’s notion of tense, and can be thought of as a generalisation of the Reichenbachian notion of tense to the realm of concepts. Reichenbach [134] proposed that each temporal expression is associated with three time points: a speech point, S, an event point, E, and reference point, R, where E refers to the time point corresponding to the event described by the tensed clause, S is (usually) taken to be the speaker’s time of utterance, and R is a temporal reference point relevant to the utterance. In LSS we extend this tripartite scheme to locative expressions in general, to which we assign a ternary structure comprising a Perspective, a Figure, and a Ground, represented symbolically as P, F, and G, and which are generalisations of the Reichenbachian S, E, and R, respectively. We show that a formal semantics based on L-structures enables us to capture important crosscategorial similarities between gradable adjectives, tenses, and spatial prepositions.

This thesis introduces a general method for incorporating the distributional analysis of textual and linguistic objects into text-to-speech (TTS) conversion systems. Conventional TTS conversion uses intermediate layers of representation to bridge the gap between text and speech. Collecting the annotated data needed to produce these intermediate layers is a far from trivial task, possibly prohibitively so for languages in which no such resources are in existence. Distributional analysis, in contrast, proceeds in an unsupervised manner, and so enables the creation of systems using textual data that are not annotated. The method therefore aids the building of systems for languages in which conventional linguistic resources are scarce, but is not restricted to these languages. The distributional analysis proposed here places the textual objects analysed in a continuous-valued space, rather than specifying a hard categorisation of those objects. This space is then partitioned during the training of acoustic models for synthesis, so that the models generalise over objects' surface forms in a way that is acoustically relevant. The method is applied to three levels of textual analysis: to the characterisation of sub-syllabic units, word units and utterances. Entire systems for three languages (English, Finnish and Romanian) are built with no reliance on manually labelled data or language-specific expertise. Results of a subjective evaluation are presented.

The use of remote techniques to capture the geometrical characteristics of rock masses has seen increased use and development in recent years. Apart from the obvious improved Health and Safety aspects, remote techniques allow rapid collection of digital data that can be subsequently analysed to provide input parameters for a variety of geomechanical applications. Remote data capture is a new technique used to collect geotechnical data and little independent work has been done concerning the comparative limitations and benefits of photogrammetry and laser scanning. Photogrammetry and laser scanning produce three dimensional digital representations of a studied rock face which can then be mapped for geotechnical data using specialist software. Research conducted at Camborne School of Mines, University of Exeter has focussed on developing robust and flexible methodologies for remote data capture techniques, namely photogrammetry and laser scanning. Geotechnical characterisation for photogrammetry was tested using the CSIRO Sirovision software and laser scanning was used with SplitFX from Split Engineering. A comparative method of assessing the error between orientation measurements was developed based on calculating the pole vector difference between remotely captured and traditionally hand-mapped data. This allowed for testing of the benefits of the remote data capture systems and limitations whilst comparing them with conventional hand-mapping. The thesis also describes the results of detailed comparisons between hand-mapping, photogrammetric and laser scanned data collection for discontinuity orientation, roughness, discontinuity trace lengths and potential end-use applications. During fieldwork in Cornwall, Brighton Cliffs and northern France it was found that remote data capture techniques struggled to collect orientation data from intensely fractured rock masses where features are primarily represented as discontinuity traces. It was found that both photogrammetry and laser scanning produce orientation data comparable to traditionally mapped data, with an average pole vector difference less than 12° from data mapped from the Tremough Campus road cutting to the University of Exeter’s Cornwall Campus. Set analysis on 151 comparable data points yielded a maximum set pole vector difference of 9.8°, where the closest difference was 2.24°. Testing the accuracy of discontinuity trace orientations captured by photogrammetry using the pole vector difference methods indicate that planar derived orientations are more accurate, with an average difference of 16.67° compared to 37.72°. This thesis contains the reviews and analyses of photogrammetry and laser scanning for use in characterising natural and manmade rock slopes. Improved field and post-processing methodologies have been developed to aid the safe, efficient and suitable geotechnical characterisation of rock fracture networks. The continual development and use of remote mapping techniques, whilst supplementing their unique qualities with traditional mapping, have the capability to revolutionise rock mass mapping. Particular development needed is the implementation of ISRM guidelines to standardise photogrammetric and laser scanning fieldwork and post-processing data analysis.

Ingeniero Civil Eléctrico / La energía eléctrica es una de las formas de energía más usadas por el ser humano. Sin ella muchas de las comodidades a las que se está habituado desaparecerían. Sin embargo uno de sus mayores consumidores es la industria, donde tan solo la idea de una mala calidad de suministro sostenida en el tiempo podría causar una gran conmoción. Es por eso que los sistemas de generación de esta energía deben ser monitoreados constantemente en búsqueda de posibles fallas o anomalías que pongan en peligro la disponibilidad de los equipos eléctricos ahí usados, en especial de las máquinas usadas para la generación. Los generadores sincrónicos son las máquinas rotatorias más usadas en la industria de la generación de energía eléctrica, es por eso que el diagnóstico de fallas para estos equipos toma gran importancia a nivel mundial. En el presente trabajo de título se diseña un algoritmo de diagnóstico de fallas orientado a detectar y clasificar fallas de tipo monofásicas para máquinas sincrónicas de polos salientes, monitoreando las corrientes de estator trifásicas y la corriente de campo. Está basado en el uso de una novedosa técnica de aprendizaje supervisado llamada Máquina de Vectores de Soporte (SVM), la cual, mediante su sistema de implementación uno contra el resto es capaz de clasificar el estado de la máquina en 4 clases distintas: sano , falla clase 1 , falla clase 2 y falla clase 3 . La SVM recibe como entrada los llamados atributos de falla, variables que se obtienen a partir de las corrientes monitoreadas y se caracterizan por poseer la información suficiente para que la SVM pueda resolver el problema de clasificación planteado. Los atributos son obtenidos a través del análisis de las corrientes de estator y de campo. Consisten en un conjunto formado por distintas frecuencias de falla (obtenidas mediante la Transformada de Fourier de las distintas señales de entrada) como también de amplitudes o características de las corrientes en el tiempo. Los datos de operación de la máquina sincrónica que son usados para entrenar, probar y validar el algoritmo de diagnóstico se obtienen a partir de simulaciones del modelo basado en la representación del Voltaje detrás de la Reactancia, este modelo implementa una novedosa forma de subdividir los devanados de estator de la máquina con el fin de simular fallas internas. El algoritmo es validado usando datos contaminados con ruido blanco Gaussiano en distintos niveles, logrando una tasa correcta de clasificación del 97:5% para datos contaminados con ruido S=N = 30[dB], lo que indica que el método propuesto es robusto ante perturbaciones y podría ser aplicado experimentalmente en el diagnóstico de fallas monofásicas en máquinas sincrónicas de polos salientes.

The widely used vector model maintains its popularity because of its simplicity, fast speed, and the appeal of using spatial proximity for semantic proximity. However, this model faces a disadvantage that is associated with the vagueness from keywords overlapping. Efforts have been made to improve the vector model. The research on improving document representation has been focused on four areas, namely, statistical co-occurrence of related items, forming term phrases, grouping of related words, and representing the content of documents. In this thesis, we propose the idea-indexing model to improve document representation for the filtering task in IR. The idea-indexing model matches document terms with the ideas they express and indexes the document with these ideas. This indexing scheme represents the document with its semantics instead of sets of independent terms. We show in this thesis that indexing with ideas leads to better performance.