In 2011 one-third of South African organisations did not intend to adopt cloud computing services because IT decision-maker lacked understanding of the related concepts and benefits (Goldstuck, 2011). This research develops a media-oriented model to examine the adoption of these services in South Africa. The model uses the technology acceptance model (TAM) and innovation diffusion theory (IDT) to develop variables that are considered determinants of adoption including trialability, complexity of understanding, perceived risk, perceived ease of use and perceived usefulness.An electronic survey was sent to 107 IT decision-makers. Over 80% of the respondents were C-suite executives. The Partial Least Squares (PLS) method was chosen to depict and test the proposed model. PLS is superior to normal regression models and is a second generation technique. The data analysis included evaluating and modifying the model, assessing the new measurement model, testing the hypotheses of the model structure and presenting the structural model.The research found that media, experts and word of mouth mitigate perceived risks including bandwidth, connectivity and power. Furthermore, trialability and perceived usefulness were affected by social influence, as well as influencing adoption. The results enable service providers and marketers to develop product roadmaps and pinpoint media messages. / Dissertation (MBA)--University of Pretoria, 2012. / Gordon Institute of Business Science (GIBS) / unrestricted

This thesis deals with different optimization problems encountered in organic synthesis. The use of response surface, sequential simplex and PLS techniques, for simultanious optimization of yield and suppression of side reactions is investigated. This is illustrated by an example of enamine synthesis, were a side reaction was a serious problem. The problem of efficient screening to find suitable catalysts and solvents in new reactions is also investigated. Here, the use of principal properties as selection criterion, is demonstrated with a new process for the silylation of a,ß-unsaturated ketones. The extension of the new method to bis silylation of 1,2- and 1,3-diketones is demonstrated. The total synthesis of (±)-geosmin is investigated by an approach aimed to reduce the number of necessary steps involved. The suggested strategy, is to find compatible solvents through several transformations in the sequence to accomplish one-pot multistep reactions. In this context an improved method for the preparation of 1,10-dimethyl-l(9)-octalone-2 was established. Comparison with previously reported total syntheses of (±)-geosmin was done. / digitalisering@umu

Conselho Nacional de Desenvolvimento Científico e Tecnológico / The quality of gasoline may be affected by the presence of several compounds. Among them, the conjugated dienes play an important role due to the fact that their presence is strongly associated with gum formation, which may clogs the injector of automobiles and may causes damages in the petroleum derivates. The main used method for the determination of total conjugated dienes is the UOP-326 method. However, the long analysis time (from 5 to 6 hours) is the main disadvantages. The available methodologies investigated as alternative to the UOP-326 method do not solve the problem properly. The present work reports the use of multivariate models to assess the diene value (DV) in pyrolysis gasoline samples starting from voltammetric and spectrophotometric data. The calibrations were carried out using the UOP-326 method instead of diene standards. In the voltammetric model, starting from a group of 24 hydrogenated pyrolysis gasoline, the PLS (Partial Least Squares) method was used to predict the DV in an independent group of 7 samples. The deviations observed were lower than 12,2% comparing to the UOP-326 method. In a group of 24 non-hydrogenated pyrolysis gasoline samples, an independent group of 7 samples was also used to predict the DV. The deviations observed were lower than 4,1%. In the spectrophotometric approach, the PLS method was used to predict the DV in an independent group of 5 samples of hydrogenated pyrolysis gasoline (n=21). The deviations observed were lower than 11% by comparing to the UOP-326 method. In a group of 26 non-hydrogenated pyrolysis gasoline samples, an independent group of 10 samples was used to predict the DV. The deviations observed were lower than 5,7%. Comparing the voltammetric and spectrophotometric methods, the former showed more reliable results with lower RMSEP (Root Mean Square Error of Prediction) values. / A qualidade da gasolina é afetada pela presença de diversos compostos. Entre eles, os dienos conjugados possuem um importante papel devido ao fato de estarem associados à formação de goma, que forma depósitos no injetor de combustível de automóveis e diminui a qualidade dos produtos petrolíferos. O método comumente utilizado para a determinação de dienos conjugados totais é o método UOP-326. Contudo, ele apresenta como principal desvantagem o longo tempo de análise (de 5 a 6 horas). As metodologias já investigadas que visam substituir o método UOP-326 na quantificação de dienos conjugados em gasolina não resolvem adequadamente o problema. Dessa forma, o presente trabalho aborda o uso de modelos multivariados para a avaliação do valor de dienos (DV) em amostras de gasolina de pirólise a partir de dados voltamétricos e espectrofotométricos, utilizando o método UOP-326 para a calibração do sistema. No modelo voltamétrico, de um grupo de 24 amostras de gasolina de pirólise hidrogenada, utilizou-se o método PLS (Regressão por Mínimos Quadrados Parciais) para a predição do DV em um grupo independente de 7 amostras, obtendo-se desvios inferiores a 12,2% quando comparado ao método UOP-326. E em 24 amostras de gasolina de pirólise não hidrogenada, um grupo independente de 7 amostras foi utilizado para a predição do DV, obtendo desvios inferiores a 4,1%. No modelo espectrofotométrico, utilizou-se o método PLS para a predição do DV em um grupo independente de 5 amostras de gasolina de pirólise hidrogenada (n=21), obtendo-se desvios inferiores a 11% quando comparado ao método UOP-326. E em 26 amostras de gasolina de pirólise não hidrogenada, um grupo independente de 10 amostras foi utilizado para a predição do DV, obtendo-se desvios inferiores a 5,7%. Na comparação entre os métodos voltamétrico e espectrofotométrico, o primeiro mostrou-se mais confiável, apresentando valores de RMSEP (erro médio dos resíduos quadráticos de predição) inferiores para ambas as amostras.

A travers le cas des fournisseurs de Marques de Distributeurs (MDD) en agro-alimentaire, cette thèse vise à montrer que la satisfaction du fournisseur peut être expliquée par la proximité entre ce dernier et son distributeur. En adoptant une posture épistémologique positiviste et une démarche hypothético-déductive, nous avons réalisé une revue de littérature qui a permis d’élaborer un modèle conceptuel. Celui-ci postule que la proximité, déclinée en quatre dimensions-proximité relationnelle, proximité identitaire, proximité de processus et proximité géographique, est un antécédent de la confiance et in fine de la satisfaction de cette relation B to B. Afin de tester les hypothèses formulées, nous avons ensuite mené une étude empirique auprès de 93 fournisseurs de MDD de la Grande Distribution Alimentaire. Une première phase de collecte des données s’est déroulée au salon MDDEXPO en avril 2014 et a permis de recueillir 51 questionnaires. La deuxième phase de collecte a été réalisée via le réseau social numérique professionnel VIADEO et a permis de recueillir 42 réponses. Puis, nous avons soumis notre modèle au test avec la méthode PLS sous le logiciel SMARTPLS3. Les résultats de cette recherche montrent que deux dimensions de la proximité permettent d’accroitre directement la satisfaction du fournisseur de MDD de la relation, sans « passer par la confiance du fournisseur de MDD envers son distributeur ». / Through the case of private label supplier in food sector, this thesis aims to show that the satisfaction of private label supplier can be explained by the proximity with his distributor. By adopting a positivist epistemological position and hypothetical-deductive approach, we conducted a literature review that allowed us to develop an integrative model made up of four dimensions: relational proximity, identity proximity, process proximity and geographical proximity. Then realized an empirical study alongside 93 suppliers of private label. A first data collection stage took place in MDDEXPO on April 2014 and has enabled to collect 51 questionnaires. The second phase of collection was done via VIADEO and which came up with 42 responses. Further, we submitted our model to test using PLS method under SMARTPLS3 software. The results of this research show that two dimensions of proximity have direct relationship with increasing private label supplier satisfaction. They are, in the order of importance of structural relations, level of cooperation (relational proximity) and adaptations (process proximity). They also indicate that three dimensions of proximity are used to increase the satisfaction of private label supplier. They are , in order of importance of structural relationships, identity proximity (shared values), social bonds (sub-scale relational proximity) and geographic proximity. Moreover, they show that two sub-dimensions of proximity do not significantly influence the confidence nor the satisfaction of private label supplier to its retailer. It is a question of information exchange (relational proximity) and idiosyncratic assets (process proximity).