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In quantum chemistry, scientists aim to solve the time-independent Schrödinger equation by employing a variety of approximation techniques whose accuracy are typically inversely proportional to their computational cost. This problem is amplified when it comes to chiral molecules, whose stereochemical assignments and associated chiroptical properties can be incredibly sensitive to small changes in their three-dimensional structure, requiring highly accurate theoretical methods. On the other hand, due to the polynomial scaling with system size, it is sometimes impractical to apply such methods to chemical compounds of broad scientific interest, especially when a multitude of low-energy conformations have to be accounted for as well. As a result, the assignment of absolute configurations to chiral compounds remains a tedious task. However, the characterization of these compounds is something that many different scientists are significantly invested in. The ultimate goal, then, is twofold: to gain useful insight by utilizing the electronic structure methods at your disposal while simultaneously developing new approximation techniques that can be used to push the boundaries on what is currently capable in computational chemistry. Therefore, we start by applying widely accepted density functional theory methods to predict optical rotations and electronic circular dichroism for naturally occurring antiplasmodial and anticancer drug candidates. We find that by comparing the computational results directly with those obtained through experimental measurement, we can provide reliable absolute config- uraitonal assignments to a variety of chiral compounds with numerous stereogenic centers. We also present the first ever prediction of vibrational circular dichroism with second-order Møller-Plesset perturbation theory. This extension opens the door to systematically improvable correlated wave function methods that can be employed when density functional theory fails or when higher accuracy results are required. / Doctor of Philosophy / Theoretical chemistry aims to draw a line from a molecule's three-dimensional structure to a set of physical observables, allowing for the efficient prediction of such properties. One family of chemical compounds for which this task becomes increasingly difficult is known as chiral molecules. A chiral compound is defined as one that has a non-superimposable mirror image. The concept of chirality is most tangibly seen with a pair of human hands, which demonstrate this same mirror-like behavior. In the same way that a person has left and right hands, a three-dimensonal handedness can be used to characterize many compounds that are essential to life including enzymes, sugars, and proteins. Although procedures have been developed to consistently isolate pure samples of such compounds, the correct identification of each hand poses a much larger task and costs the global pharmaceutical industry tens to hundreds of millions of dollars every year. As such, gaining insight about these incredibly valuable compounds and their associated properties is a never ending goal for many scientists. One such way to gain insight is through the direct comparison of experimental and calculated properties, namely chiroptical properties. These unique properties define how chiral compounds interact with light. While experimental scientists are limited in the degree to which they can probe a molecule's structure, theoretical chemists have the advantage of knowing the exact three-dimensional structure for the compound they are studying. On the other hand, theoretical chemists rely on comparison to experimental results to develop new methods or apply the available techniques to predict molecular properties. This work begins by attempting to match calculated properties to experimentally measured ones in order to confirm the detailed molecular structure of natural product drug candidates. Through multiple such computational studies, it is shown that the current methods are sometimes limited in the knowledge that they can provide. As a result, it is absolutely necessary to continue to improve on the existing methods. We go on to provide a first-of-its-kind implementation that allows for theoretical chemists to compare their results to experiment in a way that was not previously possible.

O tratamento multidocumento mostra-se indispensável no cenário atual das mídias eletrônicas, em que são produzidos diversos documentos sobre um mesmo tópico, principalmente quando se considera a explosão de informação permitida pela web. Tanto leitores quanto aplicações computacionais se beneficiam da análise discursiva multidocumento por meio da qual são explicitadas relações entre as porções dos documentos, por exemplo, relações de equivalência, contradição ou de contextualização de alguma informação. A fim de realizar o tratamento automático multidocumento, adota-se neste trabalho a teoria linguístico-computacional CST (Cross-document Structure Theory, Radev, 2000). Esse tipo de conhecimento multidocumento permite que (i) se tratem mais apropriadamente fenômenos como redundância, complementariedade e contradição de informações e, consequentemente, (ii) produzam-se sistemas melhores de processamento textual, como buscadores web mais inteligentes e sumarizadores automáticos. Neste trabalho é apresentada uma metodologia de identificação dessas relações explorando-se técnicas de aprendizado automático do paradigma tradicional e hierárquico. Para relações que não são passíveis de identificação por aprendizado automático foram desenvolvidas regras para sua identificação. Por fim, um parser é gerado contendo classificadores e regras / The multi-document treatment is essential in the current scenario of electronic media, in which many documents are produced about a same topic, mainly when considering the explosion of information allowed by the web. Both readers and computational applications are benefited by the discursive multi-document analysis, through which the relations (for example, equivalence, contradiction or background relations) among the portions of text are showed. In order to achieve the automatic multi-document treatment, the CST (Cross-document Structure Theory, Radev, 2000) is adopted in this work. This kind of knowledge allow (i) the appropriated treatment of phenomena like redundancy, complementarity and contradiction of information and, consequently, (ii) the production of better systems of text processing, as more intelligent web searchers and automatic summarizers. In this work, a methodology to identify these relations is presented exploring techniques of machine learning of the traditional and hierarchical paradigm. For relations with low frequency in the corpus, handcrafted rules were developed. Finally, a parser is generated containing classifiers and rules

In dieser Arbeit werden lambda-Strukturen und s-Strukturen eingeführt, und Funktionen S und Lambda entwickelt, die lambda-Strukturen auf s-Strukturen abbilden und umgekehrt. lambda-Strukturen sind eng verwandt mit den in von Jensen untersuchten Prämäusen (iterierbare Prämäuse dieser Art sind lambda-Strukturen), und s-Strukturen wurden in Anlehnung an die von Mitchell und Steel betrachteten Prämäuse definiert. Wieder sind iterierbare Prämäuse dieser Art auch s-Strukturen. Für die Definition dieser Strukturen wurde eine neue, schwache Form der initial segment condition entwickelt (die s'-ISC), die stark genug für die Anwendungen ist. Um zu zeigen, dass die hier entwickelten Funktionen die gewünschte Korrespondenz realisieren, wurden Methoden zur Übersetzung von Formeln entwickelt, die teilweise sehr allgemein gehalten sind. So ist die Übersetzung von Sigma-1-Formeln, die in einer Nachfolgerstufe der Jensen-Hierarchie gelten, in entsprechende Sigma-omega-Formeln in der Vorgängerstufe, anwendbar auf beliebige J-Strukturen. Es werden normale s-Iterationen eingeführt, die den normalen Iterationen von Prämäusen im Sinne von Mitchell-Steel nachgebildet sind, aber auf lambda-Strukturen angewandt werden, und es wird gezeigt, dass die entwickelten Funktionen komponentenweise auf Iterationen angewandt werden können, um normale s-Iterationen von lambda-Strukturen in normale Iterationen von s-Strukturen zu übersetzen, und umgekehrt. Mit diesen Methoden lassen sich auch Iterationsstrategien übersetzen, und man erhält, dass die entwickelten Funktionen normal s-iterierbare lambda-Strukturen auf normal iterierbare s-Strukturen abbilden, und umgekehrt. Auch bleiben die wesentlichen feinstrukturellen Größen, wie bspw. Projekta, und unter gewissen Voraussetzungen (soundness und 1-solidity) auch die Standard-Parameter, erhalten. / In this work we introduce lambda-structures and s-structures, and develop functions S and Lambda, which map lambda-structures to s-structures and vice versa. lambda-structures are closely related to the premice studied in recent work of Jensen (iterable premice of this kind are lambda-structures), and s-structures were defined with the premice developed by Mitchell and Steel in mind. Again, iterable premice of this kind are s-structures. For the definition of these structures, a new form of the initial segment condition condition, called s'-ISC, was developed, which is a common weakening of the versions used in by Steel and Jensen. It still suffices for the applications. In order to show that the functions introduced establish the desired correspondence, we developed methods for translating formulae, which in part are very generally applicable. For instance, the translation of Sigma-1-formulae which hold in a successor level of the Jensen-hierarchy into corresponding Sigma-omega-formulae in the predecessor level, can be applied to arbitrary J-structures. We introduce normal s-iterations, which have been designed so as to rebuild the iterations of premice in the sense of Mitchell-Steel but are applied to lambda-structures. It is shown that the translation functions can be applied component-wise to normal iterations, in order to translate normal s-iterations of lambda-structures into normal iterations of s-structures, and vice versa. Using these methods, we can also translate iteration strategies and the result is that the functions introduced in this work map normally s-iterable lambda-structures to normally iterable s-structures, and vice versa. Also,the fundamental fine structural notions, such as projecta, and under additional hypotheses (soundness and 1-solidity) standard-parameters, are preserved.

This thesis deals with the correlative markers d’une part… d’autre part, d’un côté… de l’autre and non seulement… mais in French and their Swedish counterparts dels… dels, å ena sidan… å andra sidan and inte bara… utan. These markers are composed of two separate parts generally occurring together, and announce a serial of at least two textual units to be considered together. The analyses of the use of these three French and three Swedish markers are based upon two corpora of non-academic humanities texts. The first, principal corpus, is composed only of original French and Swedish texts. The second, complementary corpus, is composed of source texts in the two languages and their translations in the other language. By the combination of these two corpora, this study is comparative as well as contrastive. Through application of the Geneva model of discourse analysis and the Rhetorical Structure Theory, a semantic and functional approach to correlative markers and their text-structural role is adopted. The study shows similarities as well as differences between the six markers, both within each language and between the languages. D’une part… d’autre part and dels… dels principally mark a conjunctive relation, whereas d’un côté… de l’autre and å ena sidan… å andra sidan more often are used in  a contrastive relation, even though they all can be used for both kinds of relations. Non seulement… mais and inte bara… utan mark a conjunctive relation, but can also indicate that the second argument is stronger than the first one. By the use of these two markers, the language users also present the first one as given and the second one as new information. In general, the French correlative markers appear to have a more argumentative function, whereas the text-structural function is demonstrated to be the most important in Swedish.

Η παρούσα διδακτορική διατριβή προτείνει ένα εννοιολογικό πλαίσιο σχεδιασμού μαθησιακών αντικειμένων το οποίο εμφορείται από την Κοινωνική Σημειωτική και από τη Θεωρία της Ρητορικής Δομής. Προτείνεται μια θεώρηση των μαθησιακών αντικειμένων ως πολυτροπικών ψηφιακών κειμενικών μακρο-ειδών τα οποία αποτελούνται από ψηφιακά κειμενικά μικρο-είδη. Η οργάνωση του μαθησιακού περιεχομένου μοντελοποιείται μέσα από διάφορα συστημικά δίκτυα τα οποία αναπαριστούν τις σχεδιαστικές επιλογές του δημιουργού των μαθησιακών αντικειμένων. Με αυτό το σημειωτικό πλαίσιο στη διάθεσή του ένας δημιουργός μαθησιακών αντικειμένων μπορεί να εξοπλιστεί με τα εννοιολογικά εκείνα εργαλεία τα οποία θα του επιτρέψουν: α) να δημιουργήσει ή να χρησιμοποιήσει διάφορους τύπους κειμενικών μικρο-ειδών σύμφωνα με τις επικοινωνιακές λειτουργίες που αυτά εξυπηρετούν, β) να συνδέσει μεταξύ τους αυτούς τους τύπους μέσα από μια σειρά συζευκτικών σχέσεων και γ) να εκφράσει μέσα στο μαθησιακό περιεχόμενο τις επικοινωνιακές του προθέσεις απέναντι σε μια συγκεκριμένη ομάδα – στόχο χρηστών. / This thesis proposes a conceptual framework for designing learning objects which is imbued by Social Semiotics and Rhetoric Structure Theory. An outlook of learning objects as digital multimodal macrogenres composed by digital microgenres is proposed. The organization of learning content is modeled through several systemic networks which represent the design choices of the learning objects’ author. With this semiotic framework at his disposal, a learning objects’ author can be equipped with those conceptual tools that will enable him: a) to create or use different types of microgenres according to the communicative functions they serve, b) to link these types through a series of conjunctive relations and c) to express within the learning content his communicative intentions towards a particular target group of users.

O tratamento multidocumento mostra-se indispensável no cenário atual das mídias eletrônicas, em que são produzidos diversos documentos sobre um mesmo tópico, principalmente quando se considera a explosão de informação permitida pela web. Tanto leitores quanto aplicações computacionais se beneficiam da análise discursiva multidocumento por meio da qual são explicitadas relações entre as porções dos documentos, por exemplo, relações de equivalência, contradição ou de contextualização de alguma informação. A fim de realizar o tratamento automático multidocumento, adota-se neste trabalho a teoria linguístico-computacional CST (Cross-document Structure Theory, Radev, 2000). Esse tipo de conhecimento multidocumento permite que (i) se tratem mais apropriadamente fenômenos como redundância, complementariedade e contradição de informações e, consequentemente, (ii) produzam-se sistemas melhores de processamento textual, como buscadores web mais inteligentes e sumarizadores automáticos. Neste trabalho é apresentada uma metodologia de identificação dessas relações explorando-se técnicas de aprendizado automático do paradigma tradicional e hierárquico. Para relações que não são passíveis de identificação por aprendizado automático foram desenvolvidas regras para sua identificação. Por fim, um parser é gerado contendo classificadores e regras / The multi-document treatment is essential in the current scenario of electronic media, in which many documents are produced about a same topic, mainly when considering the explosion of information allowed by the web. Both readers and computational applications are benefited by the discursive multi-document analysis, through which the relations (for example, equivalence, contradiction or background relations) among the portions of text are showed. In order to achieve the automatic multi-document treatment, the CST (Cross-document Structure Theory, Radev, 2000) is adopted in this work. This kind of knowledge allow (i) the appropriated treatment of phenomena like redundancy, complementarity and contradiction of information and, consequently, (ii) the production of better systems of text processing, as more intelligent web searchers and automatic summarizers. In this work, a methodology to identify these relations is presented exploring techniques of machine learning of the traditional and hierarchical paradigm. For relations with low frequency in the corpus, handcrafted rules were developed. Finally, a parser is generated containing classifiers and rules

M-PESA (a mobile banking service in Kenya) was introduced to offer a person-to-person money transfer service. Its extensive adoption and appropriation for purposes other than person-to-person transfers has influenced the technology providers (Safaricom) to widen their services beyond their original intentions. M-PESA provides a wide range of financial services including services for people who were previously unbanked. Users of M-PESA can now pay different utilities, those without credit cards can purchase products online, others can repay loans to microfinance institutions, pay insurance premiums, withdraw money from ATMs, use it as Point of Sale Payment and open savings accounts. This research examines the existence of “bi-directional” influences between technology and society by taking M-PESA business users as a case. It specifically investigates how M-PESA as a technology has influenced the business environment in Kenya and how the design of M-PESA has in turn been influenced by its adoption. The research adopts the Adaptive Structuration Theory as the theoretical framework and interpretive case study research as a methodological approach. Interviews with different stakeholders in the industry were used to collect data. Data was analyzed using Diachronic Analysis. The results of the research show that there is a “bi-directional” influence between technology and people as they affect each other over time. Mobile technologies shape the way businesses operate, allowing them to provide new services and improve existing ones. At the same time, usage and adoption trends affect the design of mobile technologies. Over time, technology is adapted to accommodate the new needs of businesses and other needs in the wider community. This research shows that the impact of technology depends not only on its functionality but also on its use and appropriation in society. / Dissertation (MCom)--University of Pretoria, 2011. / Informatics / unrestricted

No description available.

The share of corporate saving in total saving in South Africa has increased during the past four decades. In this dissertation various economic theories are examined in order to try to explain this change and to determine the possible implications of this change. The conclusion is that the relationship between the investment decision of companies and their savings decision is governed by the determinants of the financing choice of firms. These include cost, risk, control and availability. If, because of these factors, firms prefer to finance investment with retained earnings, there is a relationship between investment and the level of corporate saving. The degree to which the investment decision is dependent on the availability of internal financing will determine the importance of the level of corporate saving in a country. / Oor die afgelope vier dekades het die aandeel van maatskapybesparing in die totale besparing in Suid-Afika toegeneem. In hiersie vehandeling word veskillende ekonomiese teoriee ondersoek ten einde hierdie verandering te probeer veklaar en te probeer vasstel wat die implikasies van hierdie veandering is. Die gevolgtrekking waartoe gekom word, is dat die verband tussen die investeringsbeleid en die maatskappye se besparingsbesluit bepaal word deur faktore wat die finansieringskeuse van die firmas beinvloed, naamlik koste, risiko, beheer en beskikbaarheid. Indien hierdie faktore daartoe lei dat die maatskapye verkies om investering met terruggehoue bespaaring the finansier, is daar 'n verband tussen investering en die vlak van maatskappybesparing. Die mate waarin die investeringsbesluit afhanklik is van die beskikbaarheid van interne finansiering, sal bepaal hoe belangrik die vlak van maatskappybesparing in 'n land is. / Economics and Management Sciences / M.Com.