Dissertations / Theses on the topic 'Strategic extraction'

In the absence of Canadian legislation this thesis conducts an exploratory study of the regulations Canadian extraction companies (mining and oil and gas) have implemented to control private security in developing countries. It focuses on discerning what private security policies extraction companies have in place and whether companies have adopted voluntary regulations such as the Voluntary Principles on Security and Human Rights. For this study a survey was conducted of almost all extraction companies listed on the TSX and TSX Venture Exchange. Publically available documents, such as company websites, codes of conduct, annual reports, and corporate presentations, were analyzed to determine what regulations companies have in place. The data indicates that regulation of private security is mainly limited to Canada’s largest extraction companies and that private security is usually a small portion of a company’s overall corporate social responsibility policy. This research also reviews incidents of human rights abuses committed by private security personnel working for Canadian extraction companies over the last ten years. Incidents are drawn from media outlets, NGOs, and academic articles. These cases help illustrate the challenges Canadian companies face employing private security personnel on the ground.

Actinobacillus succinogenes is known to produce the acids of acetate and formate as co-products in conjunction with succinic acid. These compounds not only divert a portion of the carbon flux away from succinic acid production, but also necessitate separation techniques that further augment production costs and, as a result, render the bio-production of succinic acid unviable. To explore methods of reducing or eliminating the production of these co-products, one needs to understand the reason for their presence in the first place. This study aimed at defining the energy boundaries that describe the fermentative behaviour of the microbe. It was found that A. succinogenes displays a clear preference for routes with higher energy extraction efficiency in the early stages of its batch-operated lifespan, subsequently replacing the routes with others of lesser efficiency as fermentation progresses. This clear observation of diminishing energy extraction efficiency supports the idea of route hierarchy, i.e. routes that are more efficient at extracting energy from the available resources are favoured over those that are less efficient. Furthermore, it suggests that accumulated environmental stresses is a likely reason for the observed shift in metabolic strategies for energy extraction. This idea is further supported by the finding of co-activation between the pyruvate dehydrogenase and pyruvic acid excretion routes. Since these have vastly different energy extraction capabilities, it is postulated that the pyruvic excretory pathway is an inherent overflow response mechanism activated to limit the amount or rate of acetic acid production. This suggests a scenario in which the co-production of pyruvic acid is holistically energetically more favourable. The prevailing postulate is that the build-up of acetic acid (and formic acid), if left unchecked, might result in a runaway energy cost effect. By limiting the external pressure of passive back-diffusion, the organism is in an energetically more favourable position since less energy need be wasted on the active export of those components.
Dissertation (MSc)--University of Pretoria, 2020.
Chemical Engineering
MSc
Unrestricted

There is a transition nationwide on the analysis of forensic evidentiary stains containing biological material from traditional serology to Polymerase Chain Reaction (PCR) methodologies. The increased sensitivity of PCR, the limited number of alleles at each locus, and the necessity of producing unambiguous data for entry into the FBI's Combined DNA Index System make this study of extraction procedures of utmost importance. A "single tube" extraction procedure for blood stains collected onto FTA™ paper and a modified differential nonorganic extraction method from spermatozoa containing mixed stains were analyzed and compared. The extraction success was evaluated by amplification and typing of the amplified fragment length polymorphism, D1S80. These modifications of the nonorganic method utilized gave an improved separation of the spermatozoa-containing mixed stains.

In this project, the wave energy converter (WEC) designed at Seabased AB and Uppsala University was modelled in the program MATLAB. In order to increase the average output power, the WEC should be controlled. Therefore, the simulation tool was used to investigate damping strategies where the damping coefficient was changed at different times of the wave period. The tests showed that a suitable damping strategy, matched to the sea state at the specific location of the site and the overall WEC design, increases the average output power, as well as may protect the WEC from damages. This can lead to a more sustainable WEC system, which may contribute to the increasing demand of renewable energy solutions.

Le sujet principal de cette thèse est de proposer de nouvelles méthodes d'extractions de signaux avec applications en finance. Par signaux, nous entendons soit un signal sur lequel repose une stratégie d'investissement; soit un signal perturbé par un bruit, que nous souhaitons retrouver. Ainsi, la première partie de la thèse étudie la contagion en volatilité historique autours des annonces de résultats des entreprises du Nasdaq. Nous trouvons qu'autours de l'annonce, l'entreprise reportant ses résultats, génère une contagion persistante en volatilité à l’encontre des entreprises appartenant au même secteur. Par ailleurs, nous trouvons que la contagion en volatilité varie, selon le type de nouvelles reportées, l'effet de surprise, ou encore par le sentiment de marché à l'égard de l'annonceur. La deuxième partie de cette thèse adapte des techniques de dé-bruitage venant de l'imagerie, à des formes de bruits présentent en finance. Ainsi, un premier article, co-écrit avec Matthieu Garcin, propose une technique de dé-bruitage innovante, permettant de retrouver un signal perturbé par un bruit à variance non-constante. Cet algorithme est appliqué en finance à la modélisation de la volatilité. Un second travail s'intéresse au dé-bruitage d'un signal perturbé par un bruit asymétrique et leptokurtique. En effet, nous adaptons un modèle de Maximum A Posteriori, couramment employé en imagerie, à des bruits suivant des lois de probabilité de Student, Gaussienne asymétrique et Student asymétrique. Cet algorithme est appliqué au dé-bruitage de prix d'actions haute-fréquences. L'objectif étant d'appliquer un algorithme de reconnaissance de formes sur les extrema locaux du signal dé-bruité
The main objective of this PhD dissertation is to set up new signal extraction techniques with applications in Finance. In our setting, a signal is defined in two ways. In the framework of investement strategies, a signal is a function which generates buy/sell orders. In denoising theory, a signal, is a function disrupted by some noise, that we want to recover. A first part of this PhD studies historical volatility spillovers around corporate earning announcements. Notably, we study whether a move by one point in the announcer historical volatility in time t will generate a move by beta percents in time t+1. We find evidences of volatility spillovers and we study their intensity across variables such as : the announcement outcome, the surprise effect, the announcer capitalization, the market sentiment regarding the announcer, and other variables. We illustrate our finding by a volatility arbitrage strategy. The second part of the dissertation adapts denoising techniques coming from imagery : wavelets and total variation methods, to forms of noise observed in finance. A first paper proposes an denoising algorithm for a signal disrupted by a noise with a spatially varying standard-deviation. A financial application to volatility modelling is proposed. A second paper adapts the Bayesian representation of the Rudin, Osher and Fatemi approach to asymmetric and leptokurtic noises. A financial application is proposed to the denoising of intra-day stock prices in order to implement a pattern recognition trading strategy

Orientador: Aluir Porfírio Dal Poz
Resumo: É esperado que o operador humano permaneça, por um longo tempo, como parte integrante do sistema de extração de feições. Portanto, as pesquisas que caminham para o desenvolvimento de novos métodos semi-automáticos são ainda de grande importância. Nesta linha, esta pesquisa propõe um método semi-automático para a extração de rodovias em imagens digitais. A metodologia é uma combinação entre técnicas de correlação e estratégia de teste ativo. Os resultados experimentais obtidos da aplicação do método em imagens reais mostram que o método funciona corretamente, demonstrando que pode ser usado em esquemas de captura de dados.
Abstract: The human operator is still expected to remain as part of the feature extraction system for a relative long time. Therefore, researches for the development of new semi-automatic methods is still of great importance. Following this line, this research proposes a semi-automatic method for road extraction from digital images. It is based on a combination between correlation techniques and an active testing strategy. In order to initialize the extraction process, the operator needs to supply two close seed points plus another one at the end of road segment selected to be extracted. Experimental results obtained from the application of the method to real image data show that the method works properly, demonstrating that the developed method can be used in data capturing schemes.
Mestre

Excessive exposure to heat stress can cause a host of heat-related illnesses. For laborers, job specific work demands and protective garments greatly increase the risk of succumbing to the effects of heat stress. Microclimate cooling has been used to control heat stress exposure where administrative or engineering controls are not adequate. This study tested the performance of four personal cooling vests for use with insulated protective clothing (gas extraction coveralls) in warm-humid (35 ° C, 50% relative humidity) and hot-dry (40°C, 30% relative humidity) conditions. On 10 separate occasions, 5 male volunteers walked on a treadmill to elicit a target metabolic rate of 300 watts, for 120 minutes, while wearing a (a) water cooled vest, (b) air cooled vest, (c) frozen polymer vest (FP) (d) liquid CO2 cooling (LCO2) vest, or (e) no cooling (NC). A three-way mixed effects ANOVA was used to assess the results and a Tukey's Honestly Significant Difference multiple comparison test was used to identify where significant differences occurred ( < 0.05). The air, water, and FP systems produced significantly lower heat storage rates compared to NC. To the extent that the gas extraction coverall is worn in an environment between 30°C and 45°C and the rate of work is moderate, the FP, air and water vest were shown to manage heat storage well, reducing storage rate by about 48%, 56% and 65% respectively.

Increasing public awareness of toxic moieties in our environment has put pressure on regulatory agencies to improve testing methods so that these harmful agents can be identified and quantitated at lower and lower levels. The main objective of this work was to investigate analytical methodologies that would allow the sensitive, selective determination of pollutants to be routinely possible. Polar, thermally labile sulfur-containing pesticides and pollutants were our focus analytes. This objective was achieved in two ways: 1) the development of supercritical fluid extraction procedures suitable for these compounds and 2) the interface of a sulfur-selective detector to chromatographic techniques appropriate for thermally labile compound analysis. Supercritical fluids, particularly CO₂, have recently been shown to be suitable replacements for traditionally used organic solvents in extraction. However, due to the polarity of the sulfonyl urea herbicides and thiocarbamate insecticides studied, pure CO₂ was found to be an ineffective extractant. Polar SF mixtures (2 and 5 % methanol-modified CO₂) were investigated as alternative supercritical extraction fluids. Of the modified fluids, only 2% methanol-modified fluid could be used due to post-SFE trapping problems encountered with the 5% modified fluid. The quantitative extraction of two of these herbicides from water at the 50 ppb level was achieved using the former SF. This SF was also used to extract three thiocarbamates from apples at the 2 ppm level. In order to achieve the second objective, a sulfur-selective gas chromatographic detector, the ozone-based sulfur chemiluminescence detector (SCD), was successfully interfaced to both packed column supercritical fluid chromatography (SFC) and microcolumn high performance liquid chromatography (micro-HPLC). The packed column SFC/SCD system was shown to be compatible with both pure CO₂ and methanolmodified CO₂ mobile phases with a detector sensitivity (2 pg S/sec.) comparable to that found with capillary SFC/SCD despite the presence of more CO₂, an effective chemiluminescence quenching agent. The equimolar response of this detector to sulfur was shown to be only somewhat affected by the coelution of other organic species and improper analyte combustion conditions. For micro-column HPLC/SCD, the detector was found to be compatible with methanol/water mobile phases. Mobile phase composition, mobile phase flow rate, air flow rate, and hydrogen flow rate were found to affect the detector's sensitivity. The detector's linear dynamic range, response factor, and detection limits were determined to vary as a function of mobile phase composition. Optimum sensitivity (600 fg S/sec.) was achieved with a mobile phase of 40% methano1l60% water mobile phase compositions investigated. The analysis of polyaromatic sulfur-containing hydrocarbons (PASH's), total sulfur in diesel fuel, and sulfonyl urea herbicides was realized with the SFC/SCD system while thiocarbamate pesticides from an apple matrix were examined with the HPLC/SCD system.
Ph. D.

Avec les avantages de la non-intrusion, d'un taux d'acquisition élevé et d'un faible coût, la tomographie par impédance électrique (EIT) a été appliquée avec succès dans plusieurs cas d'instrumentation de flux polyphasique et d'imagerie clinique. La plupart des systèmes EIT actuellement utilisés reposent sur une excitation séquentielle aux électrodes voisines avec des mesures sur les autres, c'est-à-dire la stratégie adjacente, tandis que certaines stratégies d'excitation alternatives se sont révélées efficaces et faciles à mettre en œuvre en utilisant des matériels modernes. Parmi elles, la stratégie « full-scan » présente certains avantages en termes de robustesse au bruit de mesure et de qualité de l'image reconstruite. L'objectif de cette thèse est d'évaluer l'applicabilité d'un système EIT mettant en œuvre une stratégie de balayage complet à un taux d'acquisition élevé dans les mesures de débit diphasiques. La première étape consiste à évaluer les quatre stratégies d'excitation, à savoir les stratégies adjacentes, opposées, full-scan et trigonométriques, sur un certain nombre de critères pratiques et de qualité des images reconstruites, et à évaluer les influences de la taille des électrodes sur les performances d'un système EIT. Les résultats sont utiles à la conception de systèmes EIT et aux sections de test associées. La deuxième étape développe une nouvelle approche basée sur les valeurs propres pour l'estimation du taux de vide tirant parti des mesures redondantes de la stratégie de balayage complet : la reconstruction d'image EIT mal conditionnée est ainsi contournée. La troisième étape passe en revue et évalue diverses méthodes de reconstruction d'images pour les profils de conductivité à contraste élevé et à évolution rapide. Plusieurs stratégies de reconstruction réalisables, à savoir la méthode 2.5D en une itération, les méthodes 2D itératives et la méthode GREIT, sont sélectionnées pour effectuer des reconstructions de référence pour un ensemble d’expériences statiques. Enfin, le mode de mesure EIT complet, composé du système EIT développé, de la procédure de reconstruction d'image et de l'approche basée sur les valeurs propres, est appliqué aux mesures de débit en deux phases horizontales en laboratoire et environnements industriels. L'analyse des données donne un aperçu des avantages et des inconvénients de ces méthodes de mesure
With the advantages of non-intrusiveness, high acquisition rate and low-cost, Electrical Impedance Tomography (EIT) has been successfully applied in several cases in multiphase flow instrumentation and clinical imaging. Most EIT systems currently in use rely on a sequential excitation at neighboring electrodes with measurements at the remaining ones, i.e. the adjacent strategy, while some alternative excitation strategies have proven to be effective and easy to implement using modern hardwares. Amongst the so-called full-scan strategy shows certain advantages in terms of the robustness to measurement noise and the quality of reconstructed image. The objective of this thesis is to assess the applicability of an EIT system implementing full-scan strategy at a high acquisition rate in two-phase flow measurements. The first stage consists of evaluating the four excitation strategies, namely the adjacent, opposite, full-scan and trigonometric strategies, on a number of practical criteria and quality of the reconstructed images, and assessing the influences of electrode size on the performance of an EIT system. The results are worthwhile to the design of practical EIT systems and the associated test sections. The second stage develops a novel eigenvalue-based approach for phase fraction estimation leveraging the redundant measurements from full-scan strategy, the ill-posed EIT image reconstruction is circumvented. The third stage reviews and evaluates various image reconstruction methods for high contrast and fast evolving conductivity profiles, several feasible reconstruction strategies, namely one-step 2.5D method, iterative 2D methods, and GREIT method, are selected to make benchmark reconstructions for a set of static experiments. Finally, the comprehensive EIT measurement mode comprised by the developed EIT system, the image reconstruction procedure and the proposed eigenvalue-based approach, is applied to horizontal two-phase flow measurements under both laboratory and industrial environments. The analysis of the measurement data provides insights on the merits and deficiencies of the measurement mode

Today, the Democratic Republic of the Congo (DRC) ranks extremely low in terms of development indicators even by regional standards. Poverty in the country is exacerbated by the DRC's long-embedded culture of political rent-seeking and corruption, which has historically shaped the government's involvement in the mining sector. By the 1990s, the government's mismanagement of the industrial mining sector led to its decreased productivity and near decline. At the same time, the artisanal mining sector has expanded, and now employs a large amount of the country’s poor. However, many issues remain related to the legal structure governing the artisanal mining sector and opportunities for artisanal miners to sell their products. This thesis explores the potential for transforming mining practices and market structures in the DRC to better promote development and poverty alleviation.

Cette thèse explore les implications des stratégies hors marché des entreprises en termes de performance. Elle attire notamment l'attention sur la nature paradoxale des stratégies hors-marché ainsi que sur l'importance pour les entreprises de former des portefeuilles spécifiques de ce type de stratégie. En utilisant une approche fondée de la théorie de l'échange social et sur la théorie de la dépendance aux ressources, cette thèse tout d'abord analyse les conditions pour lesquelles les entreprises sont soumises à une extraction de “rente” de la part des politiciens. Elle explore ensuite l'impact de ces liens politiques sur la performance financière des entreprises. Elle distingue notamment différents types de liens politiques qui exposent les entreprises à différents niveaux d'incertitude quant à la continuité de leur échange avec les politiciens, et à différents niveaux de dépendance à leurs ressources à postériori. Enfin, cette thèse examine comment l'engagement communautaire des entreprises pourrait agir comme une stratégie complémentaire aux liens politiques, et comment cette complémentarité peut permettre d’obtenir de meilleurs retours financiers de ces liens politiques. Les hypothèses de cette thèse sont empiriquement testées sur des données longitudinales uniques couvrant différents types de liens entre l’ensemble des politiciens britanniques et toutes les sociétés cotées en bourse au Royaume-Unis, sur une période allant de 2002 à 2011. En prenant une position critique sur la valeur que les entreprises peuvent tirer des stratégies hors-marché, cette thèse contribue à la littérature en management stratégique, en particulier à celle portant sur les stratégies hors-marché des entreprises et leurs implications en termes de performance financière
This dissertation looks into performance implications of firms’ non-market strategies. It draws attention to the double-blade nature of firms’ non-market strategies, as well as the importance for the firm of forming a right portfolio of such strategies. Using insights from social exchange theory and resource dependence theory, it first outlines the conditions under which firms will be subject to rent extraction by politicians. It then looks into the impact of political linkages on firms’ financial performance, differentiating between different types of political linkages; which expose a firm to different levels of uncertainty regarding the continuity of exchange with the politician, and different levels of ex-post dependency on the politician. Finally it investigates how community engagement might act as a complement to firms’ political linkages, and how such complementarity may help to achieve improved financial returns from those political linkages. The predictions of the essays are empirically tested using a unique longitudinal dataset covering various types of linkages between all politicians and all publicly listed companies in the UK, for the period from 2002 to 2011. Taking a critical stand on the value to be drawn from firms’ non-market strategies, this dissertation contributes to strategic management literature, particularly the literature on firms’ non-market strategies and their implications on financial performance

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
É esperado que o operador humano permaneça, por um longo tempo, como parte integrante do sistema de extração de feições. Portanto, as pesquisas que caminham para o desenvolvimento de novos métodos semi-automáticos são ainda de grande importância. Nesta linha, esta pesquisa propõe um método semi-automático para a extração de rodovias em imagens digitais. A metodologia é uma combinação entre técnicas de correlação e estratégia de teste ativo. Os resultados experimentais obtidos da aplicação do método em imagens reais mostram que o método funciona corretamente, demonstrando que pode ser usado em esquemas de captura de dados.
The human operator is still expected to remain as part of the feature extraction system for a relative long time. Therefore, researches for the development of new semi-automatic methods is still of great importance. Following this line, this research proposes a semi-automatic method for road extraction from digital images. It is based on a combination between correlation techniques and an active testing strategy. In order to initialize the extraction process, the operator needs to supply two close seed points plus another one at the end of road segment selected to be extracted. Experimental results obtained from the application of the method to real image data show that the method works properly, demonstrating that the developed method can be used in data capturing schemes.

Rechargeable batteries are set to power sustainable development by 2030. In this context, the increasingly important role of certain ‘strategic minerals’ used in emerging renewable technologies has become highly topical. As the geopolitical landscape is changing as the world moves away from fossil fuels, a surge in demand for these minerals will entail an increase of production at unprecedented levels. A case in point and a focus of analysis in this thesis is the extractive sector sourcing one of the most important of transition minerals ‘cobalt’ that is predominantly mined in the Democratic Republic of the Congo (DRC). Against the challenge of a secret and non-transparent mining industry, this thesis has identified and listed all operational and openly communicative Multinational Corporations (MNC’s) extracting cobalt in the DRC. By conducting a critical discourse analysis on seven different cobalt extracting MNC’s, the analysis unveils different ways in which the companies ‘frame’ cobalt as strategic. Thus, a new and relevant ‘material-discursive framework’ has been utilised to bridge the underlying discourses of these companies with their material practices relating to cobalt. By employing this theoretical framework, the findings point at three main logics of corporate narrative the MNC’s in the sample use to form and maintain their operational activities: securitisation, environmentalism and developmentalism. Central discourses within these themes point at the way in which companies seek to maintain their economic security and legitimacy in an increasingly contested industry by continuously representing themselves as central actors with the responsibility and knowledge to deliver sustainable development for local communities affected by the industry in the DRC and for the sustainability transition.

Le décloisonnement des économies et l'accélération mondiale des échanges commerciaux ont, en une décennie à peine, transformés l'environnement concurrentiel des entreprises. La zone d'activités s'est élargie en ouvrant des nouveaux marchés à potentiels très attrayants. Ainsi en est-il des BRIC (Brésil, Russie, Inde et Chine). De ces quatre pays, impressionnants par la superficie, la population et le potentiel économique qu'ils représentent, la Chine est le moins accessible et le plus hermétique à notre compréhension de par un système linguistique distinct des langues indo-européennes d'une part et du fait d'une culture et d'un système de pensée aux antipodes de ceux de l'occident d'autre part. Pourtant, pour une entreprise de taille internationale, qui souhaite étendre son influence ou simplement conserver sa position sur son propre marché, il est aujourd'hui absolument indispensable d'être présent sur le marché chinois. Comment une entreprise occidentale aborde-t-elle un marché qui de par son altérité, apparaît tout d'abord comme complexe et foncièrement énigmatique ? Six années d'observation en Chine, nous ont permis de constater les écueils dans l'accès à l'information concernant le marché chinois. Comme sur de nombreux marchés extérieurs, nos entreprises sont soumises à des déstabilisations parfois inimaginables. L'incapacité à " lire " la Chine et à comprendre les enjeux qui s'y déroulent malgré des effets soutenus, les erreurs tactiques qui découlent d'une mauvaise appréciation du marché ou d'une compréhension biaisée des jeux d'acteurs nous ont incités à réfléchir à une méthodologie de décryptage plus fine de l'environnement d'affaire qui puisse offrir aux entreprises françaises une approche de la Chine en tant que marché. Les méthodes de l'Intelligence Economique (IE) se sont alors imposées comme étant les plus propices pour plusieurs raisons : le but de l'IE est de trouver l'action juste à mener, la spécificité du contexte dans lequel évolue l'organisation est prise en compte et l'analyse se fait en temps réel. Si une approche culturelle est faite d'interactions humaines et de subtilités, une approche " marché " est dorénavant possible par le traitement automatique de l'information et de la modélisation qui s'en suit. En effet, dans toute démarche d'Intelligence Economique accompagnant l'implantation d'une activité à l'étranger, une grande part de l'information à portée stratégique vient de l'analyse du jeu des acteurs opérants dans le même secteur d'activité. Une telle automatisation de la création de connaissance constitue, en sus de l'approche humaine " sur le terrain ", une réelle valeur ajoutée pour la compréhension des interactions entre les acteurs car elle apporte un ensemble de connaissances qui, prenant en compte des entités plus larges, revêtent un caractère global, insaisissable par ailleurs. La Chine ayant fortement développé les technologies liées à l'économie de la connaissance, il est dorénavant possible d'explorer les sources d'information scientifiques et techniques chinoises. Nous sommes en outre convaincus que l'information chinoise prendra au fil du temps une importance de plus en plus cruciale. Il devient donc urgent pour les organisations de se doter de dispositifs permettant non seulement d'accéder à cette information mais également d'être en mesure de traiter les masses d'informations issues de ces sources. Notre travail consiste principalement à adapter les outils et méthodes issues de la recherche française à l'analyse de l'information chinoise en vue de la création de connaissances élaborées. L'outil MATHEO, apportera par des traitements bibliométriques une vision mondiale de la stratégie chinoise. TETRALOGIE, outil dédié au data-mining, sera adapté à l'environnement linguistique et structurel des bases de données scientifiques chinoises. En outre, nous participons au développement d'un outil d'information retreival (MEVA) qui intègre les données récentes des sciences cognitives et oeuvrons à son application dans la recherche de l'information chinoise, pertinente et adéquate. Cette thèse étant réalisée dans le cadre d'un contrat CIFRE avec le Groupe Limagrain, une application contextualisée de notre démarche sera mise en œuvre dans le domaine des biotechnologies agricoles et plus particulièrement autour des enjeux actuels de la recherche sur les techniques d'hybridation du blé. L'analyse de ce secteur de pointe, qui est à la fois une domaine de recherche fondamentale, expérimentale et appliquée donne actuellement lieu à des prises de brevets et à la mise sur le marché de produits commerciaux et représente donc une thématique très actuelle. La Chine est-elle réellement, comme nous le supposons, un nouveau territoire mondial de la recherche scientifique du 21e siècle ? Les méthodes de l'IE peuvent-elles s'adapter au marché chinois ? Après avoir fourni les éléments de réponses à ces questions dans es deux premières parties de notre étude, nous poserons en troisième partie, le contexte des biotechnologies agricoles et les enjeux mondiaux en terme de puissance économico-financière mais également géopolitique de la recherche sur l'hybridation du blé. Puis nous verrons en dernière partie comment mettre en œuvre une recherche d'information sur le marché chinois ainsi que l'intérêt majeur en terme de valeur ajoutée que représente l'analyse de l'information chinoise

This study is intended to provide researchers with empirically derived guidelines for conducting factor analytic studies in research contexts that include dichotomous and continuous levels of measurement. This study is based on the hypotheses that ordinary least squares (OLS) factor analysis will yield more accurate parameter estimates than maximum likelihood (ML) and principal axis factor anlaysis (PAF); the level of improvement in estimates will be related to the proportion of observed variables that are dichotomized and the strength of communalities within the data sets. To achieve this study's objective, maximum likelihood, ordinary least squares, and principal axis factor extraction models were subjected to various research contexts. A Monte Carlo method was used to simulate data under 540 different conditions; specifically, this study is a four (sample size) by three (number of variables) by three (initial communality levels) by three (number of common factors) by five (ratios of categorical to continuous variables) design. Factor loading matrices derived through the tested factor extraction methods were evaluated through four measures of factor pattern agreement and three measures of congruence. To varying degrees, all of the design factors, as main effects, yielded significant differences in measures of factor loading sensitivity, agreement between sample and population, and congruence. However, in all cases, the main effects were components of interactions that yielded differences in values of these measures that were at least medium in effect size. The number of factors imbedded in the population was a component in six interactions that resulted in medium effect size differences in measures of agreement between population and sample factor loading matrices. of factor loading sensitivity, general pattern agreement, per element agreement, congruence, factor score correlations, and factor loading bias; in terms of the number of interactions that yielded at least medium effect size differences in measures of sensitivity, agreement, and congruence. The number of factors design factor exerted a larger influence than any of the other design factors. The level of communality interacted with the number of factors, number of observed variables, and sample size main effects to yield at least medium effect size differences in factor loading sensitivity, general pattern agreement, per element agreement, congruence, factor score correlations, factor loading bias, and RMSE; in terms of the number of factors that included communality as a component, this design factor exerted the second largest amount of influence on the measures of sensitivity, agreement, and congruence. The level of dichotomization, sample size, and number of observed variables were included in smaller numbers of interactions; however, these interactions yielded differences in all of the outcome variables that were at least medium in effect size. Across the majority of interactions among the manipulated research contexts, the ordinary least squares factor extraction method yielded factor loading matrices that were in better agreement with the population than either the maximum likelihood or the principal axis methods. In three of the four measures of congruence, the ordinary least squares method yielded factor loading matrices that exhibited less bias and error than the other two tested factor extraction methods. In general, the ordinary least squares method yielded factor loading matrices that correlated more strongly with the population than either of the other two tested methods. The suggested use of ordinary least squares factor analytic techniques represents the major, empirically derived recommendation derived from the results of this study. In all tested conditions, the ordinary least squares factor extraction method identified common factors with a high degree of efficacy. Suggested studies for future would incorporate the limiting constraints associated with this dissertation into methodological studies to extend the generalizability of conclusions and recommendations into areas that are beyond the scope of this dissertation.

This thesis draws on David Harvey’s concept of “accumulation by dispossession” and an international political economy (IPE) approach centred on the institutional arrangements and power structures that privilege certain actors and values, in order to critique current capitalist practices of primitive accumulation by the global corporate extractive industry. The thesis examines how accumulation by dispossession by the global extractive industry is facilitated by the “free entry” or “free mining” principle. It does so by focusing on Canada as a leader in the global extractive industry and the spread of this country’s mining laws to other countries – in other words, the transnationalisation of norms in the global extractive industry – so as to maintain a consistent and familiar operating environment for Canadian extractive companies. The transnationalisation of norms is further promoted by key international institutions such as the World Bank, which is also the world’s largest development lender and also plays a key role in shaping the regulations that govern natural resource extraction. The thesis briefly investigates some Canadian examples of resource extraction projects, in order to demonstrate the weaknesses of Canadian mining laws, particularly the lack of protection of landowners’ rights under the free entry system and the subsequent need for “free, prior and informed consent” (FPIC). The thesis also considers some of the challenges to the adoption and implementation of the right to FPIC. These challenges include embedded institutional structures like the free entry mining system, international political economy (IPE) as shaped by international institutions and powerful corporations, as well as concerns regarding ‘local’ power structures or the legitimacy of representatives of communities affected by extractive projects. The thesis concludes that in order for Canada to be truly recognized as a leader in the global extractive industry, it must establish legal norms domestically to ensure that Canadian mining companies and residents can be held accountable when there is evidence of environmental and/or human rights violations associated with the activities of Canadian mining companies abroad. The thesis also concludes that Canada needs to address underlying structural issues such as the free entry mining system and implement FPIC, in order to curb “accumulation by dispossession” by the extractive industry, both domestically and abroad.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
Depth sensing methods yield point clouds that represent neighboring surfaces. Interpreting and extracting information from point clouds is an established field, full of yet unsolved challenges. Classic image processing algorithms are not applicable or must be adapted because the organized structure of 2D images is not available. This work presents three contribution to the field of point cloud processing and segmentation. These contributions are the results of investigations carried out at the Laboratory for Education and Innovation in Automation – LEIA, aiming to advance the knowledges related to applying spacial sensing to autonomous robotics. The first contribution consists of a new algorithm, based on evolutionary methods, for extracting planes from point clouds. Based on the method proposed by Bazargani, Mateus e Loja (2015), this contribution consists of adopting evolutionary strategies in place of genetic algorithms making the process less sensitive to user-defined parameters. The second contribution is a method for segmenting ground and obstacles from point clouds for autonomous navigation, that utilizes the proposed plane extraction algorithm. The use of a quadtree for adaptive area segmentation allows for classifying points with high accuracy efficiently and with a time performance compatible with low cost embedded devices. The third contribution is a variant of the proposed segmentation method that is more noise tolerant and robust by incorporating a neural classifier. The use of a neural classifier in place of simple thresholding makes the process less sensitive to point cloud noise and faults, making it specially interesting for processing point clouds obtained from real time stereo reconstruction methods. A through sensitivity, accuracy, and efficiency analysis is presented for each algorithm. The dihedral angle metric (angle between the detected plane and the reference polygons that share at least one point) proposed by Bazargani, Mateus e Loja (2015) is used to quantify the plane detection method accuracy. The ratio between the correctly classified points and the total number of points is utilized as an accuracy metric for the ground segmentation methods. Additionally, computing costs and execution times are considered and compared to the main state-of-the-art methods.
Métodos de sensoriamento de profundidade produzem nuvens de pontos que representam as superfícies vizinhas. Interpretar e extrair informações de nuvens de pontos é um campo estabelecido e repleto de desafios ainda não superados. Algoritmos de processamento de imagens clássicos não se aplicam ou têm de ser adaptados porque a estrutura organizada que se poderia supor em imagens bidimensionais não se faz presente. Este trabalho apresenta três contribuições ao campo de processamento e segmentação de nuvens de pontos. Tais contribuições são resultados da investigação realizada no Laboratório para Educação e Inovação em Automação – LEIA, com o fim de avançar os conhecimentos relacionados a aplicações de sensoriamento espacial para robótica autônoma. A primeira contribuição consiste de um novo algoritmo para extração de planos de nuvens de pontos, que se baseia em métodos evolutivos. Partindo do método proposto por Bazargani, Mateus e Loja (2015), esta contribuição consiste em utilizar estratégias evolucionárias no lugar de algoritmos genéticos, de forma a tornar o processo menos sensível aos parâmetros definidos pelo usuário. A segunda contribuição é um método para segmentação de piso e obstáculos em nuvens de pontos para navegação autônoma, que utiliza o algoritmo de extração de planos proposto. O uso de uma árvore quaternária para segmentação adaptativa de área permite classificar os pontos com elevada taxa de acerto de forma eficiente e com desempenho compatível com dispositivos embarcados de baixo custo. A terceira contribuição é uma variação do método de segmentação proposto que se faz mais robusta e tolerante a ruído através da agregação de um classificador neural. O uso do classificador neural no lugar da limiarização simples torna o processo menos sensível a ruídos e falhas nas nuvens de pontos, o tornando especialmente interessante para o processamento de nuvens de pontos obtidas por métodos de reconstrução estéreo de tempo real. Uma completa análise de sensibilidade, acurácia e eficiência é apresentada para cada algoritmo. A métrica de ângulo diedral (ângulo entre os planos detectados e os polígonos de referência que compartilham ao menos um ponto em comum) proposta por Bazargani, Mateus e Loja (2015) é utilizada para quantificar a acurácia do método de detecção de planos. A razão entre os pontos corretamente classificados e o número total de pontos é utilizada como métrica de acurácia para os métodos de segmentação de piso. Também são considerados os custos computacionais e o tempo de execução, comparados aos principais métodos estado-da-arte.

In my thesis, I focus on the task of recognizing human iris from an image.In the beginning, the work deals with a question of biometrics, its importance and basic concepts, which are necessary for use in following text. Subsequently process of human Iris detection is described together with theory of evolution algorithms. In the implementation part, is described the design of implemented solution, which uses evolution algorithms, where is emphasis on correct pupil and iris boundary detection.

The Nigeria economy is wholly dependent on revenue from oil. However, bitumen has been discovered in the country since 1903 and has remained untapped over the years. The need for the country to complement oil exploration with the huge bitumen deposit cannot be overemphasized. This will help to improve the country's gross domestic product (GDP) and revenue available to government. Bitumen is classifled as heavy crude with API (American petroleum Institute) number ranging between 50 and 110 and occurs in Nigeria, Canada, Saudi Arabia, Venezuela etc from which petroleum products could be derived. This dissertation looked at the Canadian experience by comparing the oil and tar sand deposit found in Canada with particular reference to Athabasca (Grosmont, Wabiskaw McMurray and Nsiku) with that in Nigeria with a view of transferring process technology from Canada to Nigeria. The Nigeria and Athabasca tar sands occur in the same type of environment. These are the deltaic, fluvial marine deposit in an incised valley with similar reservoir, chemical and physical properties. However, the Nigeria tar sand is more asphaltenic and also contains more resin and as such will yield more product volume during hydro cracking albeit more acidic. The differences in the components (viscosity, resin and asphaltenes contents, sulphur and heavy metal contents) of the tar sands is within the limit of technology adaptation. Any of the technologies used in Athabasca, Canada is adaptable to Nigeria according to the findings of this research. The techno-economics of some of the process technologies are. x-rayed using the PTAC (petroleum technology alliance Canada) technology recovery model in order to obtain their unit cost for Nigeria bitumen. The unit cost of processed bitumen adopting steam assisted gravity drainage (SAGD), in situ combustion (ISC) and cyclic steam stimulation (CSS) process technology is 40.59, 25.00 and 44.14 Canadian dollars respectively. The unit cost in Canada using the same process technology is 57.27, 25.00 and 61.33 Canadian dollars respectively. The unit cost in Nigeria is substantively lesser than in Canada. A trade off is thereafter done using life cycle costing so as to select the best process technology for the Nigeria oil/tar sands. The net present value/internal rate of return is found to be B$3,062/36.35% for steam assisted gravity drainage, B$I,570124.51 % for cyclic steam stimulation and B$3,503/39.64% for in situ combustion. Though in situ combustion returned the highest net present value and internal rate of return, it proved not to be the best option for Nigeria due to environmental concern and response time to production. The best viable option for the Nigeria tar sand was then deemed to be steam assisted gravity drainage. An integrated oil strategy coupled with cogeneration using MSAR was also seen to considerably amplify the benefits accruable from bitumen exploration; therefore, an investment in bitumen exploration in Nigeria is a wise economic decision.
Thesis (M.Ing. (Development and Management))--North-West University, Potchefstroom Campus, 2010.

Delay-insensitive (DI) circuits are asynchronous circuits whose functional correctness is independent of the delays in their components and the interconnecting wires. The environment and circuit module follows a specified usage protocol, sometimes called handshake signals. It has been believed that purely DI circuits are easy to test because any fault will prevent the generation of an acknowledge signal. We show that this is not always true under a general set of components. A Petri net fault model is used to reveal the possibility of critical races/hazards during test. A design for test method using observation points is shown which guarantees 100% fault coverage, and structural theorems are proved which can reduce/eliminate these observation points. No automated techniques exist so far for reducing the test length of these circuits, in particular, two-phase transition signaling circuits which contain implicit state encoding. Since there can be very few combinational components, classic scan design would not apply. A theory for control point insertion is presented for test length reduction. The major difficulty is in deriving a safe hazard-free test; the specified usage protocol does not directly apply because of the alterations made. Algorithms based on partial order protocol extraction and partial states are presented which produce provably correct test behaviors. Finally, an impossibility result is proved for fault tolerance in the most common class of DI circuit.

Dissertação de mestrado integrado em Engineering and Management of Information Systems
Nowadays, the task of collecting data from Web sources is becoming increasingly complex. This complexity arises, in part, from the large data volume (and continues to increase), as well as from the proliferation of platforms that make them available. Based on the previous assumption, this dissertation project had as main objective the identification of strategies that allow the extraction of data from Web sources. In order to reach this goal, the following tasks were defined: identification of tools and frameworks that aid in the extraction process of data, tests with the tools and frameworks identified, development of a framework that illustrates possible strategies for the extraction of data and finally the application of the proposed framework in a Practical Case. The proposed framework consists of a methodology with possible strategies for extracting data from web sources. The Practical Case was carried out on the ALGORITMI Research Centre of the University of Minho. In the first instance, the data of the authors in the ALGORITMI Research Centre are collected. Other data are then collected from other sources, such as their publications and later stored in a relational database. The collections and decisions taken during the study case are based on the application of the proposed framework. The insertion of the data obtained from different sources in a single location allows the creation of a Single Entry Point for reading data, that is, we have a single data source. The creation of this unique data source will allow the user to access all the data desired without the need to spend time trying to locate it The present work is organized in five chapters: introduction (where a brief description is given to the problem and objectives of the work), literary review (concepts, methodologies and strategies for obtaining data from Web sources), framework proposal, application of the proposed framework in a Practical Case that focuses on the ALGORITMI Research Centre and finally the conclusion (where some considerations are woven and some proposals for future work are presented).
Nos dias de hoje, a tarefa de recolha de dados proveniente de fontes Web está a tornar-se cada vez mais complexa. Esta complexidade surge, em parte, do grande volume de dados existente (e que continua a aumentar), assim como, da proliferação de plataformas que os disponibilizam. Tendo por base o pressuposto anterior, este projeto de dissertação teve como principal objetivo a identificação de estratégias que possibilitam a extração de dados de fontes Web. Para alcançar esse objetivo foram definidas as seguintes tarefas: identificação de ferramentas e frameworks que auxiliam no processo de extração de dados, realização de testes com as ferramentas e frameworks identificados, desenvolvimento de um framework que ilustra as estratégias possíveis para a extração de dados e por fim a aplicação do framework proposto num caso de estudo. O framework proposto consiste numa metodologia com as estratégias possíveis para a extração de dados provenientes de fontes web. O caso de estudo realizado incide sobre o Centro ALGORITMI da Universidade do Minho. Em primeira instância procede-se à recolha dos dados dos autores existentes no Centro ALGORITMI. De seguida são recolhidos outros dados de outras fontes, tais como, as suas publicações e posteriormente armazenados numa base de dados relacional. As recolhas e decisões tomadas no decorrer do caso de estudo baseiam-se na aplicação do framework proposto. A inserção dos dados obtidos de diferentes fontes num único local permite a criação de um Single Entry Point para a leitura de dados, ou seja, passamos a possuir uma única fonte de dados. A criação desta fonte única de dados permitirá ao utilizador aceder aos dados que pretende sem a necessidade de despender muito tempo à sua procura. O presente trabalho encontra-se organizado em cinco capítulos sendo eles: introdução (onde é efetuada uma descrição ao problema e objetivos do trabalho), revisão literária (conceitos, metodologias e estratégias para obtenção de dados de fontes Web), framework (proposta e explicação da metodologia desenvolvida), caso de estudo (aplicação do framework proposto num caso de estudo que incide sobre o centro ALGORITMI) e conclusão (onde são tecidas consideração e apresentadas algumas propostas para trabalhos futuros).

博士
國立清華大學
電機工程學系
85
This study discusses the search strategies for image matching under object''sgeometric transformations, e.g., scaling, rotation, and translation, etc. Itis noted that geometric variations will cause a tremendous search space. Ifthe search space is not reduced, invariant features must be extracted beforematching. However, conventional methods merely extract partial imageinformation to achieve invariance. That will result in worse matchingperformance than the results by using original images for matching. Hence, themain purpose of this dissertation is to propose matching systems that cansearch for the possible best match of objects in a much reduced search spaceby means of an appropriate search strategy. In view of the generalapplications, the main concerned issues in this study include static imagematching and dynamic image matching. Static image matching denotes thematching between two still images. Dynamic image matching represents thematching in an image sequence, in which consecutive two images are used formatching. Although the methods for static image matching might also beutilized for matching consecutive two images in an image sequence, it is stillnecessary to invent an efficient approach for dynamic matching whenconsidering the computational cost and the characteristics of dynamic imagematching. The search strategy for static image matching is based on theregistration concept, by which the geometric discrepancy between the testpattern and the related reference pattern can be reduced by applyingsimilarity transformation to the test pattern with the transformationparameters estimated from the control points. The automatically paired controlpoints are the centroids of desired regions in patterns with specific graylevel distributions. Thereby, the search space can then be much reduced. Theresidual geometric variations resulted from the proposed method are smallerthan those resulted from image normalization method which utilizes imagemoments to evaluate normalization angle and scaling. Through the analysis ofintrinsic invariance properties, only a small number of reference templatesare required to deal with the residual geometric variations of the transformedtest pattern. Consequently, a simple similarity measure (correlation) can thenbe directly employed without any scale and rotation invariant featuresextraction. Furthermore, the control point sets can be utilized as the initialmathing of two image patterns. As a result, some similarity measure can thenbe omitted if the point pattern matching reports a correct and convincingmatch of the two patterns. That will save much time for two dimensional imagecorrelation. The extension of two images'' matching is the matching in an imagesequence. Conventional single-template correlator tends to bring about aconsiderable amount of walk-off errors due to the clutter effect or that theobject in the search scene varies greatly in orientation. That will cause aconsiderable amount of search space as stated in static image matching. Inaddition, the invariant features extraction is not feasible in the dynamicimage matching. Hence, a dual- template search strategy for dynamic imagematching is proposed to seek the possible best match of objects between twoconsecutive images. In this dual-template search strategy, the AOI of thecurrent frame is correlated with the ''precedent first'''' template and the''precedent second'''' one for seeking the possible best match of objects. Ithas the advantage that no significant increase of computational burden of thesystem is needed since these two correlations can be implemented in a parallelmanner and no complicated invariant features extraction is required. By meansof an uncertainty model of correlation peaks, the results of the dualcorrelations are analyzed and combined within the intersection of two circulargates determined by the model. Therefore, the search space is diminished andthe possible best match of objects in consecutive frames can then be easilysearched. Two techniques are proposed for this correlation data fusion andoptimization: by probabilistic Bayesian estimation or by fuzzy inference. Itwill be shown that the proposed dual-template search strategy outperforms theconventional single-template correlators implemented in either matched filteror circular harmonic filter. In addition, the proposed method exhibits thecapability of walk-off suppression.

Le sujet principal de cette thèse est de proposer de nouvelles méthodes d'extractions de signaux avec applications en finance. Par signaux, nous entendons soit un signal sur lequel repose une stratégie d'investissement; soit un signal perturbé par un bruit, que nous souhaitons retrouver. Ainsi, la première partie de la thèse étudie la contagion en volatilité historique autours des annonces de résultats des entreprises du Nasdaq. Nous trouvons qu'autours de l'annonce, l'entreprise reportant ses résultats, génère une contagion persistante en volatilité à l’encontre des entreprises appartenant au même secteur. Par ailleurs, nous trouvons que la contagion en volatilité varie, selon le type de nouvelles reportées, l'effet de surprise, ou encore par le sentiment de marché à l'égard de l'annonceur. La deuxième partie de cette thèse adapte des techniques de dé-bruitage venant de l'imagerie, à des formes de bruits présentent en finance. Ainsi, un premier article, co-écrit avec Matthieu Garcin, propose une technique de dé-bruitage innovante, permettant de retrouver un signal perturbé par un bruit à variance non-constante. Cet algorithme est appliqué en finance à la modélisation de la volatilité. Un second travail s'intéresse au dé-bruitage d'un signal perturbé par un bruit asymétrique et leptokurtique. En effet, nous adaptons un modèle de Maximum A Posteriori, couramment employé en imagerie, à des bruits suivant des lois de probabilité de Student, Gaussienne asymétrique et Student asymétrique. Cet algorithme est appliqué au dé-bruitage de prix d'actions haute-fréquences. L'objectif étant d'appliquer un algorithme de reconnaissance de formes sur les extrema locaux du signal dé-bruité
The main objective of this PhD dissertation is to set up new signal extraction techniques with applications in Finance. In our setting, a signal is defined in two ways. In the framework of investement strategies, a signal is a function which generates buy/sell orders. In denoising theory, a signal, is a function disrupted by some noise, that we want to recover. A first part of this PhD studies historical volatility spillovers around corporate earning announcements. Notably, we study whether a move by one point in the announcer historical volatility in time t will generate a move by beta percents in time t+1. We find evidences of volatility spillovers and we study their intensity across variables such as : the announcement outcome, the surprise effect, the announcer capitalization, the market sentiment regarding the announcer, and other variables. We illustrate our finding by a volatility arbitrage strategy. The second part of the dissertation adapts denoising techniques coming from imagery : wavelets and total variation methods, to forms of noise observed in finance. A first paper proposes an denoising algorithm for a signal disrupted by a noise with a spatially varying standard-deviation. A financial application to volatility modelling is proposed. A second paper adapts the Bayesian representation of the Rudin, Osher and Fatemi approach to asymmetric and leptokurtic noises. A financial application is proposed to the denoising of intra-day stock prices in order to implement a pattern recognition trading strategy

abstract: Synechocystis sp PCC 6803 is a photosynthetic cyanobacterium that can be easily transformed to produce molecules of interest; this has increased Synechocystis’ popularity as a clean energy platform. Synechocystis has been shown to produce and excrete molecules such as fatty acids, isoprene, etc. after appropriate genetic modification. Challenges faced for large–scale growth of modified Synechocystis include abiotic stress, microbial contamination and high processing costs of product and cell material. Research reported in this dissertation contributes to solutions to these challenges. First, abiotic stress was addressed by overexpression of the heat shock protein ClpB1. In contrast to the wild type, the ClpB1 overexpression mutant (Slr1641+) tolerated rapid temperature changes, but no difference was found between the strains when temperature shifts were slower. Combination of ClpB1 overexpression with DnaK2 overexpression (Slr1641+/Sll0170+) further increased thermotolerance. Next, we used a Synechocystis strain that carries an introduced isoprene synthase gene (IspS+) and that therefore produces isoprene. We attempted to increase isoprene yields by overexpression of key enzymes in the methyl erythritol phosphate (MEP) pathway that leads to synthesis of the isoprene precursor. Isoprene production was not increased greatly by MEP pathway induction, likely because of limitations in the affinity of the isoprene synthase for the substrate. Finally, two extraction principles, two–phase liquid extraction (e.g., with an organic and aqueous phase) and solid–liquid extraction (e.g., with a resin) were tested. Two–phase liquid extraction is suitable for separating isoprene but not fatty acids from the culture medium. Fatty acid removal required acidification or surfactant addition, which affected biocompatibility. Therefore, improvements of both the organism and product–harvesting methods can contribute to enhancing the potential of cyanobacteria as solar–powered biocatalysts for the production of petroleum substitutes.
Dissertation/Thesis
Ph.D. Plant Biology 2013

The amount of information available through the Internet has been showing a significant growth in the last decade. The information can result from various sources such as scientific experiments resulting from particle acceleration, recording the flight data of a commercial aircraft, or sets of documents from a given domain such as medical articles, news headlines from a newspaper, or social networks contents. Due to the volume of data that must be analyzed, it is necessary to endow the search engines with new tools that allow the user to obtain the desired information in a timely and accurate manner. One approach is the annotation of documents with their relevant expressions. The extraction of relevant expressions from natural language text documents can be accomplished by the use of semantic, syntactic, or statistical techniques. Although the latter tend to be not so accurate, they have the advantage of being independent of the language. This investigation was performed in the context of LocalMaxs, which is a statistical method, thus language-independent, capable of extracting relevant expressions from natural language corpora. However, due to the large volume of data involved, the sequential implementations of the above techniques have severe limitations both in terms of execution time and memory space. In this thesis we propose a distributed architecture and strategies for parallel implementations of statistical-based extraction of relevant expressions from large corpora. A methodology was developed for modeling and evaluating those strategies based on empirical and theoretical approaches to estimate the statistical distribution of n-grams in natural language corpora. These approaches were applied to guide the design and evaluation of the behavior of LocalMaxs parallel and distributed implementations on cluster and cloud computing platforms. The implementation alternatives were compared regarding their precision and recall, and their performance metrics, namely, execution time, parallel speedup and sizeup. The performance results indicate almost linear speedup and sizeup for the range of large corpora sizes.

碩士
華梵大學
工業管理學系碩士班
95
Like all manufacturers are facing constantly global competition, it is vital for the pre-recorded disk industry to run production plan as planned. Currently, most pre-recorded manufacturers usually rely on experience that may lead to wrong direction of resource allocation and hence delayed lead-time, and finally lose necessary profit. Therefore, this study would like to find out a reasonable schedule that meets clients’ lead-time requests and company’s profit target. In this research, based on a real case application, some order extracting strategies were developed and tested so that the overloaded schedules can be reduced and bring company the best efficiency and profit. The simulation results of this study illustrate that one order extracting strategy outperforms than the others in lead-time performance, volume of delayed order and profit.

Dissertação de mestrado, Inovação Química e Regulamentação (Erasmus Mundus), Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2017
Platinum group metals (PGMs) are highly demanding metals in current high-techs. However, their supply is limited due to their scarcity in natural resources and expensive mining. Previously, several techniques proposed for the recovery of PGMs from secondary sources are still eco-unfriendly and expensive. In the present study, solvent extraction in combination with cheap, operationally easy and safe techniques involving microbial communities were employed for the recovery of Pd(II) from aqueous media. Accordingly, extraction of Pd(II) by N,N’- dimethyl-N,N’-dicyclohexylthiodiglycolamide (DMDCHTDGA) in toluene and subsequent stripping of Pd(II) with an acidic thiourea solution were performed, followed by bio-Pd recovery through the use of biogenic sulphide generated by a sulphate-reducing bacteria community. The results revealed that an excellent Pd(II) extraction performance of DMDCHTDGA from binary, tertiary and complex mixtures at 2, 4 and 6 M HCl feed solutions was observed. However, Fe(III) was co-extracted from 4 and 6 M HCl feed solutions, being completely removed with deionized water in the scrubbing stage. Regarding stripping, 94-99% of extracted Pd(II) were stripped using acidic thiourea solution. Concerning palladium biorecovery, over 99% of stripped Pd(II) were recovered using biogenic sulphide obtained from a bioremediation process and Postgate B medium, in batch assay. Similarly, > 99 % palladium recovery was achieved by directly connecting Pd(II) solution with effluent from bioremediation process. Likewise, 78-99% of scrubbed Fe(III) were bio-recovered. Analysis of the precipitate collected during palladium bio-recovery testified that the precipitate was composed by Pd and S, and consistent with the synthesis of PdS nanoparticles. The elemental analysis of iron precipitate showed the presence of other metals besides Fe and S. Henceforth, the method engaged is environmentally sustainable, safe and cheap, thus attractive to be employed aiming the recovery of Pd or Fe from wastes materials.
Os metais do grupo da platina (PGMs) são metais determinantes em aplicações high-tech atuais. No entanto, o seu abastecimento é limitado devido à sua escassez em recursos naturais e práticas de mineração dispendiosas. Anteriormente, várias técnicas propostas para a recuperação de PGMs de fontes secundárias são ainda pouco ecológicas e caras. No presente estudo, a extração por solventes em combinação com técnicas baratas, operacionalmente fáceis e seguras envolvendo comunidades microbianas foram empregues para a recuperação de Pd(II) a partir de meios aquosos. Consequentemente, realizou-se a extração de Pd(II) por N,N'- dimetil-N,N'-diciclo-hexiltiodiglicolamida (DMDCHTDGA) em tolueno e subsequente remoção de Pd(II) com uma solução ácida de tioureia, seguida de recuperação de bio-Pd através do uso de produtos metabólicos (S2-) gerados por uma comunidade de bactérias que reduzem iões sulfato. Observou-se um bom desempenho de extração de Pd(II) pela DMDCHTDGA de misturas binárias, terciárias e complexas a partir de soluções de alimentação de 2, 4 e 6 M HCl. No entanto, o Fe(III) foi co-extraído das soluções 4 e 6 M HCl, sendo completamente removido com água desionizada na etapa de lavagem. Em relação à re-extração, 94-99% de Pd(II) extraído foi removido usando solução ácida de tioureia. No que diz respeito à recuperação biológica de paládio, foram recuperados mais de 99% de Pd(II) utilizando sulfato biologicamente gerado obtido a partir do processo de biorremediação e do meio de Postgate B, respetivamente, no ensaio em lote. Da mesma forma, > 99% de Pd(II) foi recuperado conectando diretamente a solução de Pd(II) com o efluente do processo de biorremediação. Além disso, 78-99% de Fe(III) foram também bio-recuperados. A análise do precipitado recolhido durante a bio-recuperação de Pd(II) mostrou que o precipitado era composto por Pd e S, e consistente com a síntese de nanopartículas de PdS. A análise elementar de precipitados de ferro mostrou a presença de outros metais além de Fe e S. O método agora desenvolvido é ambientalmente sustentável, seguro e barato, e atrativo para ser empregue na recuperação de Pd ou Fe de materiais esgotados ou em fim de vida útil.

Tese de Doutoramento, Ciências do Mar da Terra e do Ambiente, Ramo: Ciências e Tecnologias do Ambiente, Especialidade em Biotecnologia, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2016
The present work explored the potential of chemical (solvent extraction) and biological (using anaerobic bacterial community) technologies, aiming the removal/recovery of precious metals from aqueous solutions. Solvent extraction or liquid-liquid extraction was used to find a suitable platinum and palladium extractant, to be applied to the treatment of aqueous solutions containing these metals. Thus, N,N’-dimethyl-N,N’-dicyclohexyltetradecylmalonamide (DMDCHTDMA), N,N’-dicyclohexyl-N,N’-dimethylsuccinamide (DMDCHSA) and N,N’-dimethyl-N,N’-diphenylsuccinamide (DMDPHSA) were tested and proved to be efficient at extracting platinum (IV) from HCl solutions. Platinum (IV) was then successfully stripped from DMDCHTDMA using 1 M HCl solution, and from DMDCHSA and DMDPHSA, using seawater. These extractants proved to be less efficient for palladium (II) removal, thus, for this metal, biological strategies were tested. A palladium (II)-resistant bacterial community, able to biorecover palladium from solutions, was found. The phylogenetic analysis showed that this community was mainly composed by bacteria close to Clostridium species, however, bacteria affiliated to genera Bacteroides and Citrobacter were also identified. The potentialities of combining solvent extraction and the use of bacterial communities for palladium and platinum recovery were also demonstrated. Pd(II) and Pt(IV) in aqueous phases were efficiently extracted to organic phases. The metals were then stripped with seawater, precipitated and recovered using a filtered solution from bacterial growth. The successful precipitation of palladium (II) and platinum (IV), as nanosized PdS and PtS2 particles, was accompanied by sulphide concentration decrease in the bacterial growth solution. Biological processes, using effluents from an acid mine drainage bioremediation treatment system, were tested for gold recovery from aqueous solutions. The use of these effluents, with dissolved biogenic sulphide, proved to be an excellent alternative for Au(III) recovery as Au(0) nanoparticles (NPs). Finally, biogenic sulphide, from the effluents tested before, was also used to successfully synthesize Ag2S NPs and Ag2S/TiO2 nanocomposite. The Ag2S NPs and Ag2S/TiO2 nanocomposite obtained have semiconductor properties and can theoretically be used for radiation based applications.
O principal objetivo do presente trabalho foi explorar as potencialidades de tecnologias química e biológica, para a remoção/recuperação de metais preciosos de soluções aquosas. A abordagem química focou-se no uso da técnica de extração líquido-líquido, também conhecida como extração por solventes. Assim, foram estudados alguns extratantes, diamidas, de forma a extrair metais do grupo da platina, no caso, platina e paládio, a partir de soluções de ácido clorídrico. A utilização de consórcios de bactérias anaeróbias para a remoção e/ou recuperação de metais preciosos (ouro, prata, paládio e platina) a partir de soluções aquosas, preferencialmente sob a forma de NPs, também foi explorada. Para além destas duas abordagens, ainda foi testada a combinação de ambas as metodologias, química e biológica, na recuperação de metais do grupo da platina a partir de soluções aquosas. Os metais preciosos (ouro, prata e metais do grupo da platina – PGM - platina, paládio, ruténio, irídio e ródio) têm vindo a desempenhar um papel de destaque na sociedade atual, dadas as suas inúmeras aplicações, nomeadamente como catalisadores em processos orgânicos, componentes de valor acrescentado em ligas metálicas, conversores catalíticos em veículos, nas indústrias química, farmacêutica, petrolífera e eletrónica, assim como em joalharia. Esta crescente procura dos metais preciosos, conduziu ao aumento da escassez das suas fontes primárias. Por conseguinte, e uma vez que o valor económico destes metais assim o justifica, a investigação de processos para a sua separação tem vindo a crescer, com particular incidência na utilização de materiais ou métodos inovadores, que permitam a sua recuperação seletiva e rentável. A implementação de processos que permitam a valorização de efluentes, ou a reciclagem de diferentes materiais no período final da sua vida útil, que contenham metais preciosos é extremamente urgente e importante. Diversas abordagens têm vindo a ser estudados para a remoção e recuperação de metais preciosos, no entanto, métodos químicos como a extração por solventes e a troca iónica, e métodos biológicos usando bactérias anaeróbias, têm ganho especial foco. Alguns autores têm investigado o uso de derivados de malonamidas N,N’-tetrasubstituídas na extração de iões metálicos presentes em soluções de lixiviação cloretadas, usando a extração por solventes. No presente trabalho, foi seguida a abordagem da extracção líquido-líquido, em busca de extratantes para a platina e para o paládio, que possam ser aplicados a soluções de lixiviação, nomeadamente resultantes do tratamento de fontes secundárias. Para tal, um derivado de malonamida N,N’-tetrassubstituído - N,N’-dimetil-N,N’-diciclohexiltetradecilmalonamida (DMDCHTDMA) – e dois derivados de succinamidas N,N´-tetrasubstituídas - N,N’-diciclohexil-N,N’-dimetilsuccinamida (DMDCHSA) e N,N’-dimetil-N,N’-difenilsuccinamida (DMDPHSA) – foram sintetizados e o seu potencial extractante foi investigado na extração líquido-líquido de Pt(IV), a partir de soluções cloretadas. Os resultados revelaram que a platina (IV) pode ser extraída de forma eficiente por qualquer um dos três extractantes testados. Posteriormente, a platina foi re-extraída, com sucesso, da solução da DMDCHTDMA carregada com o metal, através de um simples contacto com uma solução de HCl 1M. A platina também foi re-extraída num só passo e com sucesso das fases orgânicas carregadas de DMDCHSA e DMDPHSA, usando água do mar. Estes extractantes, apesar de serem bastante eficientes na extração da platina, não se mostraram tão eficientes na extração de paládio, pelo que foram testados métodos biológicos para a remoção de paládio (II) de soluções aquosas. Diversos métodos biológicos têm vindo a ser propostos e estudados, apresentando algumas vantagens relativamente aos métodos químicos, nomeadamente serem mais seguros a nível ambiental (produzem menos resíduos ou efluentes) e serem uma tecnologia de baixo custo (normalmente operam nas condições ambientais, sem que seja necessário gastos energéticos adicionais e sem necessidade de reagentes). Assim, a biorecuperação baseada na utilização de microrganismos tem sido considerada como alternativa potencialmente viável. De facto, é conhecido que os microrganismos podem ser utilizados na remoção de iões metálicos de soluções aquosas através de reações de precipitação ou de redução, que conduzem à formação de NPs metálicas. Tendo como base as considerações anteriores, no presente trabalho foram realizados estudos com vista à remoção e recuperação de metais preciosos a partir de soluções aquosas, usando consórcios de bactérias anaeróbias. Assim, lamas provenientes de Estações de Tratamento de Águas Residuais foram enriquecidas, de modo a promover preferencialmente o crescimento de bactérias redutoras de sulfato, bem conhecidas como tendo capacidade bioremediadora de metais. A comunidade enriquecida foi exposta a diferentes concentrações de paládio (II), tendo sido possível encontrar uma comunidade bacteriana não só resistente ao paládio (~20 mg/L), como também com capacidade para o remover da solução. A análise filogenética permitiu concluir que este consórcio bacteriano é essencialmente composto por bactérias da espécie Clostridium, não obstante, bactérias do género Bacteroides e Citrobacter também foram identificadas. Posteriormente, testou-se pela primeira vez as potencialidades da combinação da extração líquido-líquido com o uso de comunidades bacterianas para a recuperação de paládio e platina, sob a forma de NPs de sulfuretos metálicos. Estes sulfuretos metálicos de dimensões nanométricas têm aplicações funcionais já conhecidas e demonstradas. Assim, o Pd(II) e a Pt(IV) presentes em soluções aquosas foram extraídos eficientemente para fases orgânicas compostas por DMDCHSA e por DMDCHTDMA em 1,2-dicloroetano, respetivamente. Os metais, agora presentes nas fases orgânicas, foram re-extraídos, com elevado sucesso, utilizando água do mar. Para a recuperação do metal da solução aquosa utilizou-se uma solução filtrada, proveniente do crescimento e atividade do consórcio bacteriano obtido anteriormente. A precipitação, praticamente total, dos metais, foi acompanhada por uma diminuição do sulfureto presente na solução (proveniente do crescimento bacteriano), ocorrendo assim a formação de NPs de PdS e de PtS2. Para a recuperação do ouro de soluções aquosas utilizou-se um processo baseado na utilização do efluente proveniente de um processo de bioremediação de uma Água Ácida de Mina (AMD). A utilização deste efluente, contendo sulfureto gerado biologicamente, num processo de recuperação de ouro, provou ser uma excelente alternativa para a obtenção de ouro metálico sob a forma de NPs. Deste modo, este método permite simultaneamente tratar um efluente e obter um produto de elevado valor económico, como são as NPs de Au(0). Por fim, este mesmo efluente foi utilizado de forma similar à utilizada na recuperação de NPs de Au(0), para a bioremoção de prata de meios aquosos, tendo originado síntese de NPs de Ag2S. Uma vez que esta síntese apresentou inicialmente, num sistema em batch, um rendimento de ~100%, foi realizado um scale-up para um sistema acoplado a jusante do processo de bioremediação de AMD em contínuo (anteriormente já utlizado na recuperação do ouro). Esta síntese permitiu obter NPs de Ag2S ainda mais pequenas (tamanhos entre 15-24 nm) do que as obtidas em batch (tamanhos até 54 nm). Também foi realizada com sucesso a síntese de nanocompósitos de Ag2S/TiO2, acoplada ao sistema de bioremediação de AMD. As partículas do nanocompósito Ag2S/TiO2 apresentaram dimensões compreendidas entre 30 e 60 nm, justificadas pelas partcículas de TiO2 apresentarem na sua superfície partículas de Ag2S, como mostrado pelos resultados da microscopia electrónica. Todas as NPs sintetizadas provaram apresentar características semicondutoras, o que lhes confere a possibilidade teórica de serem utilizadas em processos fotocatalíticos. Com este trabalho, foi possível encontrar bons extratantes e agentes de re-extração, nunca antes reportados, para a extração de platina a partir de soluções cloretadas. Também demonstrou-se ser possível obter consórcios bacterianos, a partir de amostras ambientais, resistentes e com capacidade de remover paládio de soluções aquosas. Concluiu-se também que a combinação da extracção líquido-líquido e do uso de comunidades bacterianas permite recuperar a platina e o paládio presentes em soluções aquosas, sob a forma de NPs de sulfuretos metálicos. Por fim, provou-se que um efluente proveniente de um processo de bioremediação de AMD, contendo sulfureto gerado biologicamente, pode ser eficientemente utilizado na recuperação de ouro de soluções aquosas, obtendo-se NPs de ouro metálico. Este mesmo efluente permite ainda sintetizar NPs Ag2S e o nanocompósito Ag2S/TiO2, com propriedades semicondutoras. Todas a partículas recuperadas nas diversas etapas do trabalho podem ser utilizadas nas aplicações já conhecidas para as mesmas, ou testadas para outros fins.

L’aptitude à reconnaitre les expressions faciales des autres est cruciale au succès des interactions sociales. L’information visuelle nécessaire à la catégorisation des expressions faciales d’émotions de base présentées de manière statique est relativement bien connue. Toutefois, l’information utilisée pour discriminer toutes les expressions faciales de base entre elle demeure encore peu connue, et ce autant pour les expressions statiques que dynamiques. Plusieurs chercheurs assument que la région des yeux est particulièrement importante pour arriver à « lire » les émotions des autres. Le premier article de cette thèse vise à caractériser l’information utilisée par le système visuel pour discriminer toutes les expressions faciales de base entre elles, et à vérifier l’hypothèse selon laquelle la région des yeux est cruciale pour cette tâche. La méthode des Bulles (Gosselin & Schyns, 2001) est utilisée avec des expressions faciales statiques (Exp. 1) et dynamiques (Exp. 2) afin de trouver quelles régions faciales sont utilisées (Exps. 1 et 2), ainsi que l’ordre temporel dans lequel elles sont utilisées (Exp. 2). Les résultats indiquent que, contrairement à la croyance susmentionnée, la région de la bouche est significativement plus utile que la région des yeux pour discriminer les expressions faciales de base. Malgré ce rôle prépondérant de la bouche, c’est toute de même la région des yeux qui est sous-utilisée chez plusieurs populations cliniques souffrant de difficultés à reconnaitre les expressions faciales. Cette observation pourrait suggérer que l’utilisation de la région des yeux varie en fonction de l’habileté pour cette tâche. Le deuxième article de cette thèse vise donc à vérifier comment les différences individuelles en reconnaissance d’expressions faciales sont reliées aux stratégies d’extraction de l’information visuelle pour cette tâche. Les résultats révèlent une corrélation positive entre l’utilisation de la région de la bouche et l’habileté, suggérant la présence de différences qualitatives entre la stratégie des patients et celle des normaux. De plus, une corrélation positive est retrouvée entre l’utilisation de l’œil gauche et l’habileté des participants, mais aucune corrélation n’est retrouvée entre l’utilisation de l’œil droit et l’habileté. Ces résultats indiquent que la stratégie des meilleurs participants ne se distingue pas de celle des moins bons participants simplement par une meilleure utilisation de l’information disponible dans le stimulus : des différences qualitatives semblent exister même au sein des stratégies des participants normaux.
The ability to recognize facial expressions is crucial for the success of social communication. The information used by the visual system to categorize static basic facial expressions is now relatively well known. However, the visual information used to discriminate the basic facial expressions from one another is still unknown, and this is true for both static and dynamic facial expressions. Many believe that the eye region of a facial expression is particularly important when it comes to reading others' emotions. The aim of the first article of this thesis is to determine which information is used by the visual system in order to discriminate between the basic facial expressions and to verify the validity of the hypothesis that the eye region is crucial for this task. The Bubbles method (Gosselin & Schyns, 2001) is used with static (Exp. 1) and dynamic (Exp. 2) facial expressions in order to determine which facial areas are used for the task (Exp. 1) and in which temporal order these facial areas are used (Exp. 2). The results show that, in contrast with the aforementioned belief, the mouth region is significantly more useful than the eye region when discriminating between the basic facial expressions. Despite this preponderant role of the mouth, it is the eye area⎯not the mouth area⎯that is underutilized by many clinical populations suffering from difficulties in recognizing facial expressions. This observation could suggest that the utilization of the eye area varies as a function of the ability to recognize facial expressions. The aim of the second article in this thesis is thus to verify how individual differences in the ability to recognize facial expressions relate to the visual information extraction strategies used for this task. The results show a positive correlation between the ability of the participants and the utilization of the mouth region, suggesting the existence of qualitative differences between the strategy of clinical patients and of normal participants. A positive correlation is also found between the ability of the participants and the utilization of the left eye area, but no correlation is found between the ability and the utilization of the right eye area. These results suggest that the difference between the strategies of the best and the worst participants is not only that the best ones use the information available in the stimulus more efficiently: rather, qualitative differences in the visual information extraction strategies may exist even within the normal population.

La présente thèse avait pour mandat d’examiner la question suivante : quels sont les indices visuels utilisés pour catégoriser le sexe d’un visage et comment sont-ils traités par le cerveau humain? La plupart des études examinant l’importance de certaines régions faciales pour la catégorisation du sexe des visages présentaient des limites quant à leur validité externe. L’article 1 visait à investiguer l’utilisation des indices achromatiques et chromatiques (sur l’axe xy) dans un contexte de plus grande validité externe. Pour ce faire, nous avons utilisé la technique Bubbles afin d’échantillonner l’espace xy de visages en couleurs n’ayant subi aucune transformation. Afin d’éviter les problèmes liés à la grande répétition des mêmes visages, nous avons utilisé un grand nombre de visages (c.-à-d. 300 visages caucasiens d’hommes et de femmes) et chaque visage n’a été présenté qu’une seule fois à chacun des 30 participants. Les résultats indiquent que la région des yeux et des sourcils—probablement dans le canal blanc-noir—est l’indice le plus important pour discriminer correctement le genre des visages; et que la région de la bouche—probablement dans le canal rouge-vert—est l’indice le plus important pour discriminer rapidement et correctement le genre des visages. Plusieurs études suggèrent qu’un indice facial que nous n’avons pas étudié dans l’article 1—les distances interattributs—est crucial à la catégorisation du sexe. L’étude de Taschereau et al. (2010) présente toutefois des données allant à l’encontre de cette hypothèse : les performances d’identification des visages étaient beaucoup plus faibles lorsque seules les distances interattributs réalistes étaient disponibles que lorsque toutes les autres informations faciales à l’exception des distances interattributs réalistes étaient disponibles. Quoi qu’il en soit, il est possible que la faible performance observée dans la condition où seules les distances interattributs étaient disponibles soit explicable non par une incapacité d’utiliser ces indices efficacement, mais plutôt par le peu d’information contenue dans ces indices. L’article 2 avait donc comme objectif principal d’évaluer l’efficacité—une mesure de performance qui compense pour la faiblesse de l’information disponible—des distances interattributs réalistes pour la catégorisation du sexe des visages chez 60 participants. Afin de maximiser la validité externe, les distances interattributs manipulées respectaient la distribution et la matrice de covariance observées dans un large échantillon de visages (N=515). Les résultats indiquent que les efficacités associées aux visages ne possédant que de l’information au niveau des distances interattributs sont un ordre de magnitude plus faibles que celles associées aux visages possédant toute l’information que possèdent normalement les visages sauf les distances interattributs et donnent le coup de grâce à l’hypothèse selon laquelle les distances interattributs seraient cuciale à la discrimination du sexe des visages. L’article 3 avait pour objectif principal de tester l’hypothèse formulée à la fin de l’article 1 suivant laquelle l’information chromatique dans la région de la bouche serait extraite très rapidement par le système visuel lors de la discrimination du sexe. Cent douze participants ont chacun complété 900 essais d’une tâche de discrimination du genre pendant laquelle l’information achromatique et chromatique des visages était échantillonnée spatiotemporellement avec la technique Bubbles. Les résultats d’une analyse présentée en Discussion seulement confirme l’utilisation rapide de l’information chromatique dans la région de la bouche. De plus, l’utilisation d’un échantillonnage spatiotemporel nous a permis de faire des analyses temps-fréquences desquelles a découlé une découverte intéressante quant aux mécanismes d’encodage des informations spatiales dans le temps. Il semblerait que l’information achromatique et chromatique à l’intérieur d’une même région faciale est échantillonnée à la même fréquence par le cerveau alors que les différentes parties du visage sont échantillonnées à des fréquences différentes (entre 6 et 10 Hz). Ce code fréquentiel est compatible avec certaines évidences électrophysiologiques récentes qui suggèrent que les parties de visages sont « multiplexées » par la fréquence d’oscillations transitoires synchronisées dans le cerveau.
In this thesis, we asked which face cues are used for gender discrimination and how they are processed by the humain brain. The few studies have tried to answer this question used only a small set of grayscale stimuli, often distorted and presented a large number of times. In Article 1, we reassessed the importance of chromatic and achromatic facial cues for gender categorisation in a more realistic setting. We used the Bubbles technique to sample the xy plane of a set of 300 color photographs of Caucasian faces, each presented only once to 30 participants. Results show that the region of the eyes and the eyebrows—probably in the light-dark channel—is the most important facial cue for accurate gender discrimination; and that the mouth region is also driving fast correct responses (but not fast incorrect responses)—the gender discrimination information in the mouth region is concentrated in the red-green color channel. Several studies suggest that a cue which we did not examine in Article 1—interattribute distances (e.g. the interpupil distance)—is critical for gender discrimination. A recent study by Taschereau-Dumouchel et al. (2010) challenged this idea by showing that participants were nearly at chance when asked to identify faces on the sole basis of real-word interattribute distances, while they were nearly perfect when all other facial cues were shown. However, it remains possible that humans are highly tuned to interattribute distances but that the information conveyed by these cues is scarce. In Article 2, we tested this hypothesis by contrasting the efficiencies—a measure of performance that factors out task difficulty—of 60 observers in six face-gender categorization tasks. Most importantly, efficiencies for faces that varied only in terms of their interattribute distances were an order of magnitude lower than efficiencies for faces that varied in all respects except their interattribute distances or in all respects. These results provide a definitive blow to the idea that real-world interattribute distances are critical for face gender categorization. In Article 3, we tested and confirmed the hypothesis formulated at the end of Article 1 according to which observers would rapidly extract chromatic information in the mouth region during sex categorization. One hundred and twelve participants each performed 900 trials of a face gender categorization task in which the achromatic and isoluminant chromatic content of faces were partially revealed in space and time with Bubbles. This experiment also allowed us to perform time-frequency analyses, which showed that achromatic and isoluminant chromatic information within the same facial part were sampled by the brain at the same frequency, whereas different facial parts were sampled at distinct frequencies (ranging from 6 to 10 Hz). This sampling code is consistent with recent electrophysiological evidence suggesting that facial features are multiplexed by the frequency of transient synchronized oscillations in the brain.

Questionnaires translated into Shona
Mineral extraction is one of the key drivers of Africa’s economies and is also one of the largest industries in the world. In many African countries, including Zimbabwe, mining contributes to profound parts of the economy and remain the engine for economic growth. In recent years, and following the continual exploitation of minerals, mining companies have been scrutinized as a major cause of social, environmental, and economic problems faced mainly by communities at the margins. In this regard, mining companies are widely perceived to be prospering at the expense of adjacent communities, who are the primary recipients of the externalities, mainly negative, from mining operations. Due to incongruent stakeholder interests conflicts have erupted given the peculiar case of the extractive industries in Zimbabwe. Having realised the differences among stakeholder interests over minerals, in the extractive industry the study sought to answer this question: how is CCE understood by different stakeholders? And how is CCE measured by the same stakeholders?. The focus of the study is to evaluate the meaning of CCE from multiple stakeholders in the extractive industry in Zimbabwe; and to analyse how CCE is measured by identified stakeholders. In order to satisfy the stated objectives, the study employed mixed research method. This study revealed similarity in understanding of CCE and its usefulness amongst the different stakeholder groups. Of cognitive importance is the realisation by stakeholders on the need for proactive communities and corporate investment into community for effective partnerships. Collaboration, empowerment, inclusion, trust and organisation emerged to be the major facilitators for CCE. The study presents operative CCE according to the obligations and expectations of stakeholders. Having realised that mining industries are particularly susceptible to conflict between stakeholders, the study suggests proactive desire to mitigate these conflicts through CCE in the mining industry. In this respect, community development, peace and stability and strong economy are the major outcomes of effective CCE. The study recommends participation of resource owners in planning, implementing, monitoring and evaluation as well as dividends sharing of mining projects as advocated for by the CCE Model. It is also recommended that the adoption of the CCE Model will ensure a sustainable and harmonious coexistence between the predominantly capitalistic mining concerns and the resource owners and solve part of the current impasse to business and community development.
Business Management
D.B.L.