The thesis is dedicated to the approximation of high-dimensional functions from scattered data nodes. Many methods in this area lack the property of interpretability in the context of explainable artificial intelligence. The idea is to address this shortcoming by proposing a new method that is intrinsically designed around interpretability. The multivariate analysis of variance (ANOVA) decomposition is the main tool to achieve this purpose. We study the connection between the ANOVA decomposition and orthonormal bases to obtain a powerful basis representation. Moreover, we focus on functions that are mostly explained by low-order interactions to circumvent the curse of dimensionality in its exponential form. Through the connection with grouped index sets, we can propose a least-squares approximation idea via iterative LSQR. Here, the proposed grouped transformations provide fast algorithms for multiplication with the appearing matrices. Through global sensitivity indices we are then able to analyze the approximation which can be used in improving it further. The method is also well-suited for the approximation of real data sets where the sparsity-of-effects principle ensures a low-dimensional structure. We demonstrate the applicability of the method in multiple numerical experiments with real and synthetic data.:1 Introduction 2 The Classical ANOVA Decomposition 3 Fast Multiplication with Grouped Transformations 4 High-Dimensional Explainable ANOVA Approximation 5 Numerical Experiments with Synthetic Data 6 Numerical Experiments with Real Data 7 Conclusion Bibliography / Die Arbeit widmet sich der Approximation von hoch-dimensionalen Funktionen aus verstreuten Datenpunkten. In diesem Bereich leiden vielen Methoden darunter, dass sie nicht interpretierbar sind, was insbesondere im Kontext von Explainable Artificial Intelligence von großer Wichtigkeit ist. Um dieses Problem zu adressieren, schlagen wir eine neue Methode vor, die um das Konzept von Interpretierbarkeit entwickelt ist. Unser wichtigstes Werkzeug dazu ist die Analysis of Variance (ANOVA) Zerlegung. Wir betrachten insbesondere die Verbindung der ANOVA Zerlegung zu orthonormalen Basen und erhalten eine wichtige Reihendarstellung. Zusätzlich fokussieren wir uns auf Funktionen, die hauptsächlich durch niedrig-dimensionale Variableninteraktionen erklärt werden. Dies hilft uns, den Fluch der Dimensionen in seiner exponentiellen Form zu überwinden. Über die Verbindung zu Grouped Index Sets schlagen wir dann eine kleinste Quadrate Approximation mit dem iterativen LSQR Algorithmus vor. Dabei liefern die vorgeschlagenen Grouped Transformations eine schnelle Multiplikation mit den entsprechenden Matrizen. Unter Zuhilfenahme von globalen Sensitvitätsindizes können wir die Approximation analysieren und weiter verbessern. Die Methode ist zudem gut dafür geeignet, reale Datensätze zu approximieren, wobei das sparsity-of-effects Prinzip sicherstellt, dass wir mit niedrigdimensionalen Strukturen arbeiten. Wir demonstrieren die Anwendbarkeit der Methode in verschiedenen numerischen Experimenten mit realen und synthetischen Daten.:1 Introduction 2 The Classical ANOVA Decomposition 3 Fast Multiplication with Grouped Transformations 4 High-Dimensional Explainable ANOVA Approximation 5 Numerical Experiments with Synthetic Data 6 Numerical Experiments with Real Data 7 Conclusion Bibliography

The event tourism industry is one of the fastest growing tourism industries worldwide. One type of event that is growing immensely is festivals, especially music festivals such as the Cape Town International Jazz Festival. As a result of the fast growing pace of festivals, it has become crucial for a festival to sustain itself in the market place to stay competitive. The Cape Town International Jazz Festival (the Jazz Festival) is a fast growing music festival and hosts numerous well–known local and international jazz artists, as well as young up–and–coming artists. For this exciting Jazz Festival to keep growing, it needs to be sustainable. To achieve this, the organisers and managers of the Jazz Festival need to know what is important to the visitors of the Jazz Festival, so they can fulfil their needs. This in turn leads to satisfied visitors that will return to the Jazz Festival and keep the festival sustainable. Generally speaking, music festivals have a more professional management approach than other tourism events and thus are more likely to be more successful. Key Success Factors (KSFs) are a precondition for the success of any event and will influence the competitiveness of the event in the market place. It is imperative for organisers to identify the KSFs that are important to the visitors so as to provide them with a satisfactory experience. This will also assist in measuring the achievement of the event’s goals and objectives. The main purpose of this study was to determine the KSFs in managing the visitor experience at the Cape Town International Jazz Festival. To reach this goal, the study is divided into two articles. Research for both articles was conducted at the Cape Town International Jazz Festival through distributing 400 questionnaires randomly throughout the two days of the festival, which was held on 3 and 4 April 2010. Article 1 is titled: “Key aspects for efficient and effective management of the Cape Town International Jazz Festival: a visitor’s perspective”. The main purpose of this article was to identify the Key Success Factors in managing the Cape Town International Jazz Festival, to determine what visitors deemed as important when attending the Jazz Festival. A factor analysis was done to achieve this goal. Results indicated that Hospitality Factors, Quality Venues, Information Dissemination, Marketing and Sales, and Value and Quality are the KSFs that are of importance when managing the Jazz Festival. The results of this article provided festival managers with valuable information when organising an event such as the Cape Town International Jazz Festival. Article 2 is titled: “The importance of different Key Success Factors to different target markets of the Cape Town International Jazz Festival based on travel motives”. The main purpose of this article was to determine whether different target markets that are visiting the Jazz Festival, deemed different KSFs as important, depending on their travel motives. An analysis of variance (ANOVA) was done to determine if there were statistically significant differences between the three clusters and the KSFs that they deemed important. Results showed that the three clusters, namely, Escapists, Culture Seekers and Jazz Lovers, deemed different KSFs as important when they are visiting the Jazz Festival. The results of this article gave festival organisers and marketing managers insight as to which markets to focus scarce marketing resources on and which markets to keep growing, as they will sustain the festival in the long term. Therefore, this research revealed the KSFs that are of utmost importance when managing the Cape Town International Jazz Festival, and that these aspects differ for certain markets. Organisers therefore need to assess the KSFs to provide products that will satisfy the visitor in order for him/her to return each year and keep the festival competitive and sustainable. / Thesis (M.Com. (Tourism))--North-West University, Potchefstroom Campus, 2012.

The event tourism industry is one of the fastest growing tourism industries worldwide. One type of event that is growing immensely is festivals, especially music festivals such as the Cape Town International Jazz Festival. As a result of the fast growing pace of festivals, it has become crucial for a festival to sustain itself in the market place to stay competitive. The Cape Town International Jazz Festival (the Jazz Festival) is a fast growing music festival and hosts numerous well–known local and international jazz artists, as well as young up–and–coming artists. For this exciting Jazz Festival to keep growing, it needs to be sustainable. To achieve this, the organisers and managers of the Jazz Festival need to know what is important to the visitors of the Jazz Festival, so they can fulfil their needs. This in turn leads to satisfied visitors that will return to the Jazz Festival and keep the festival sustainable. Generally speaking, music festivals have a more professional management approach than other tourism events and thus are more likely to be more successful. Key Success Factors (KSFs) are a precondition for the success of any event and will influence the competitiveness of the event in the market place. It is imperative for organisers to identify the KSFs that are important to the visitors so as to provide them with a satisfactory experience. This will also assist in measuring the achievement of the event’s goals and objectives. The main purpose of this study was to determine the KSFs in managing the visitor experience at the Cape Town International Jazz Festival. To reach this goal, the study is divided into two articles. Research for both articles was conducted at the Cape Town International Jazz Festival through distributing 400 questionnaires randomly throughout the two days of the festival, which was held on 3 and 4 April 2010. Article 1 is titled: “Key aspects for efficient and effective management of the Cape Town International Jazz Festival: a visitor’s perspective”. The main purpose of this article was to identify the Key Success Factors in managing the Cape Town International Jazz Festival, to determine what visitors deemed as important when attending the Jazz Festival. A factor analysis was done to achieve this goal. Results indicated that Hospitality Factors, Quality Venues, Information Dissemination, Marketing and Sales, and Value and Quality are the KSFs that are of importance when managing the Jazz Festival. The results of this article provided festival managers with valuable information when organising an event such as the Cape Town International Jazz Festival. Article 2 is titled: “The importance of different Key Success Factors to different target markets of the Cape Town International Jazz Festival based on travel motives”. The main purpose of this article was to determine whether different target markets that are visiting the Jazz Festival, deemed different KSFs as important, depending on their travel motives. An analysis of variance (ANOVA) was done to determine if there were statistically significant differences between the three clusters and the KSFs that they deemed important. Results showed that the three clusters, namely, Escapists, Culture Seekers and Jazz Lovers, deemed different KSFs as important when they are visiting the Jazz Festival. The results of this article gave festival organisers and marketing managers insight as to which markets to focus scarce marketing resources on and which markets to keep growing, as they will sustain the festival in the long term. Therefore, this research revealed the KSFs that are of utmost importance when managing the Cape Town International Jazz Festival, and that these aspects differ for certain markets. Organisers therefore need to assess the KSFs to provide products that will satisfy the visitor in order for him/her to return each year and keep the festival competitive and sustainable. / Thesis (M.Com. (Tourism))--North-West University, Potchefstroom Campus, 2012.

A utilização de produtos provenientes de fontes renováveis e livres de substâncias tóxicas é tendência global, prova disso é o constante aumento da demanda por produtos à base de madeira. Segundo o Forest Products Statistics (2015), a produção mundial de painéis de madeira reconstituída, em 2014, foi de 388 milhões de m³, um aumento de 5,5% em comparação com o ano anterior e um aumento de 34% quando comparado com 2010. No entanto, o setor industrial de painéis de madeira há décadas enfrenta um grande desafio com relação às emissões tóxicas vindas dos adesivos convencionais. Diante destes problemas, a proposta do presente trabalho foi testar a viabilidade da produção de painéis aglomerados e painéis OSB, com significativa redução da emissão de formaldeído, a partir de resíduos de madeira de Pinus sp. e Tectona grandis (Teca). Neste sentido, buscou-se contribuir para o aumento do conhecimento científico sobre a utilização do polímero natural polihidroxibutirato (PHB) e do resíduo de tinta à base de resina epóxi como adesivos alternativos. Os painéis foram fabricados variando-se os parâmetros de produção para obtenção de melhores condições de processo, sendo estes: densidade baixa, média e alta; teor de adesivo de 20, 30 e 40%; adição de partículas de Teca nas proporções de 0, 25, 50, 75, 100%. O desempenho físico-mecânico dos painéis foi avaliado com base nas normas ABNT NBR 14810 (2013) e ANSI A208.1 (2009). Realizou-se análise de variância (ANOVA) para testar a influência dos fatores individuais (densidade, percentual de adesivo e fração de Teca), além das interações entre tais fatores nas propriedades físico-mecânicas dos painéis. Os resultados apontaram para excelentes propriedades físicas e mecânicas dos painéis aglomerados de média e alta densidade, tendo resíduo de tinta, principalmente, nas proporções de 30 e 40%. Na maioria dos casos as propriedades de tais painéis foram superiores aos requisitos estipulados pela norma brasileira e pelas internacionais. Assim, ficou confirmada a viabilidade de produção dos aglomerados com pelo menos um dos insumos estudados bem como seu potencial de emprego para as finalidades compatíveis com produtos desta natureza. / The use of products from renewable sources and free of toxic substances is a global trend, the proof is the steady increase in demand for wood-based products. According to the Forest Products Statistics (2015), world production of reconstituted wood panels in 2014 was 388 million cubic meters, an increase of 5.5% compared to the previous year and an increase of 34% compared to 2010. However, the industrial sector of wood panels for decades faces a major challenge with regard to toxic emissions coming from conventional adhesives. Faced with these problems, the purpose of this study was to test the feasibility of production of panels and OSB panels, with significant reduction of formaldehyde emissions from wood waste Pinus sp. and teak (Teak). In this sense, we sought to contribute to the increase of scientific knowledge on the use of natural polymer polyhydroxybutyrate (PHB) and residual ink resin-based epoxy as alternative adhesives. The panels were manufactured by varying the production parameters to obtain the best processing conditions, namely: low density, medium and high; resin content of 20, 30 and 40%; adding particles of Teak in proportions of 0, 25, 50, 75, 100%. The physical-mechanical performance of the panels was evaluated based on the standards NBR 14810 (2013) and ANSI A208.1 (2009). Held analysis of variance (ANOVA) to test the influence of individual factors (density, adhesive percentage and fraction Teak), and the interactions among these factors in the physical-mechanical properties of the panels. The results showed excellent physical and mechanical properties of the panels average clusters and high density, and ink residue, mainly in the proportions of 30 and 40%. In most cases the properties of these boards were superior to the requirements set by the Brazilian and international standards. Thus, it was confirmed production of agglomerates with at least one viability of inputs studied as well as their potential for employment for purposes compatible with products of this nature.

Les entreprises et plus généralement les organisations sont confrontées à des enjeux climatiques et économiques avec pour obligation de respecter un cadre légal et des orientations définis à des plus grandes échelles (régionale, nationale et internationale). Une organisation est souvent au fait du but ou de l’objectif à atteindre ; en revanche le moyen d’y parvenir peut nécessiter de l’apprentissage voire de la recherche. Le but de cette thèse est de fournir une méthodologie à l’usage des organisations pour réaliser le management stratégique des projets relatifs à leur transition énergétique. A partir de différents états de l’art sur la planification énergétique et la conception en particulier, nous avons pointé le déficit méthodologique auquel doit faire face une organisation : si les démarches et outils existent lorsqu’un problème est clairement identifié, comment justement identifier un ou des problèmes à partir uniquement d’une formulation de buts ou d’intentions ? La première partie propose une démarche de planification énergétique à l’échelle d’une organisation qui fait émerger, de manière structurée, les problèmes auxquels l’organisation sera potentiellement confrontée. Notre démarche repose sur l’utilisation des BEGES et des méthodes de management de l’énergie/GES d’une part, complétés par des démarches et outils de conception d’autre part. Ces derniers facilitent la consolidation des informations et des données nécessaires pour formuler et structurer les problèmes à résoudre. A l’issue de cette démarche certains problèmes sont formulés sous forme de contradictions et de conflits. La démarche développée est purement qualitative et adaptée au travail de groupe avec des experts. Cependant certaines données numériques traduisent des comportements de systèmes qui sont peu maitrisés par les parties prenantes du projet. La deuxième partie propose une méthode combinant la simulation et l’analyse de données pour identifier les contradictions d’objectifs et de cause qui peuvent ou semblent empêcher l’atteinte des objectifs. Ces contradictions sont formulées de sorte à pouvoir être traitées avec les méthodes de résolution de problèmes inventifs. Le principe d’identification des contradictions d’objectifs repose sur la transformation des réponses expérimentales ou de simulation des systèmes étudiés en données qualitatives binaires et sur l’identification des Paretos optimaux des données ainsi transformées. Les contradictions de causes concernent les facteurs ou paramètres de conception qui induisent les conflits d’objectifs. Nous proposons de les identifier à l’aide d’une méthode d’analyse discriminante binaire à base d’apprentissage supervisé associée à l’ANOVA. Nous montrons sur un cas d’étude, d’une part, comment intégrer cette approche dans la démarche présentée en partie 1 du mémoire, et d’autre part, comment l’utiliser pour obtenir des concepts de solutions dans un contexte multi-objectifs (diminution des consommations d’énergie, des émissions de GES, du coût etc.). / Companies and more generally organizations are confronted with climatic and economic issues, they have to respect a legal framework and orientations defined in larger scales (regional, national and international). An organization usually knows the goal or the objective to be achieved; however the way to do can require learning or even research. The goal of this thesis is to provide a methodology for the use of organizations to realize strategic management of their energy transition projects. From many different states of the art about energy planning and conception in particular, we show the methodological deficit which an organization has to face: if approaches and tools exist when a problem is clearly identified, how actually identify one or several problems from only a goal or intention formulation? The first part proposes an energy planning approach at an organizational scale to bring out in structured way problems which the organization may be confronted. Our approach is based on greenhouse gas emission assessments and energy/GHG management methods which are completed with conception approaches and some tools and methodologies. They facilitate the consolidation of required information and data to formulate and structure problems to solve. As a result of our approach some problems are formulated as contradictions and conflicts. The developed approach is purely qualitative and adapted to workgroup with experts. However some numerical data translate system behaviors which are sparsely mastered by project stakeholders. The second part proposes a combined method of simulation and data analysis to identify objective and cause contradictions which can or seem to prevent achieving the objectives. These contradictions are formulated in such a way to be handled with methods of resolution of inventive problems. The identification of objective contradictions is based on the transformation of experimental or simulation answers of the studied systems in binary qualitative data and on the identification of optimal Pareto of the transformed data. Cause contradictions concern conception factors or parameters which induce objective conflicts. We suggest identifying these contradictions with a binary discriminant analysis method based on supervised learning associated with ANOVA. On one hand, we show on a study case how integrate this initiative into the presented approaches in part 1 and on the other hand, how use it to obtain solution concepts in a multi-objective context (energy consumptions, GHG emissions or cost reduction etc.).

Baserat på Self-Determination Theory (SDT) och en randomiserad kontrollstudiedesign undersöktes effekten av autonomistödjande textmeddelanden i jämförelse med neutrala meddelanden eller inga meddelanden på deltagarnas behovstillfredsställelse, motivation, och aktivitetsnivå. Digital kvantitativ datainsamling användes där webbenkäterna skickades ut tre gånger till deltagarna, innan, under samt efter intervention. Totalt 107 frivilliga män och kvinnor svarade vid baslinjemätningen och delades sedan in i tre olika grupper, inaktiv kontrollgrupp (n = 45), aktiv kontrollgrupp (n = 29) samt interventionsgrupp (n = 33). Interventionen ägde rum i samband med en stegtävling. Textmeddelandena skickades ut till deltagarna i aktiva kontrollgruppen och interventionsgruppen två gånger varje vecka under åtta veckor, via en digital plattform. Det förelåg inga signifikanta skillnader mellan grupperna vid baslinjemätningen. En tvåvägs-ANOVA (repeated measure) visade att interventionen hade en signifikant effekt på upplevelsen av tillhörighet under interventionen. Dock förelåg inga andra signifikanta interventionseffekter. Det sammanlagda resultatet antyder således att den digitala interventionen, det vill säga att tillhandahålla deltagarna med autonomistödjande textmeddelanden, inte har någon bestående effekt på deltagarnas behovstillfredsställelse, motivation eller aktivitetsnivå. / Based on Self-Determination Theory (SDT) and a randomized controlled trial design, the effect of autonomy-supportive text messages was examined in comparison with neutral messages or no messages regarding the participants basic psychological needs, motivation and activity level. Digital quantitative data collection was used, and the web surveys were sent out three times to participants, pre, during and post intervention. A total of 107 male and female volunteers responded to the baseline measurement and were then divided into three different groups, inactive control group (n = 45), active control group (n = 29) and intervention group (n = 33). The intervention took place in relation to a step contest. Text messages were sent to the participant’s in the active control group and intervention group twice a week for a total of eight weeks, via a digital platform. There were no significant differences between the groups in the baseline measurement. A two-way ANOVA (repeated measure) showed that the intervention had a significant effect on the experience of relatedness during the intervention. However, there were no other significant intervention effects. The results suggest that the digital intervention, to provide participants with autonomy supportive text messages, does not have a lasting effect on need satisfaction, motivation or activity level.

La technologie laser est couramment utilisée dans les industries aéronautiques depuis les années 1980. La découpe au laser, comme étant un procédé d’enlèvement de matière, offre plus d’avantages que les procédés conventionnels de la découpe. Parmi les apports du laser, l’absence de contact mécanique avec le matériau à usiner, une limitation de contamination des matériaux et une production élevée due à une haute vitesse de coupe. Les alliages de titane et les composites intermétalliques à base de titane jouent un rôle important dans le domaine de la science et de l’ingénierie ainsi ils permettent de satisfaire les activités de fabrication avancée dans les industries aéronautiques. L’amélioration de ce procédé de fabrication est souhaitable pour augmenter les performances techniques et accentuer l’intérêt économique. Les travaux réalisés ont porté sur l’étude et l’analyse des effets des paramètres de l’usinage par faisceau laser sur l’intégrité de la surface en termes de qualité et morphologie de la surface usinée de plusieurs matériaux, tels que, le titane pur, les alliages de titaneTi-6Al-4V et Ti6242 et le composite intermétallique à base de titane afin d’optimiser les conditions de découpage par laser.La sélection des paramètres de coupe dans le processus d’usinage laser tels que la puissance du laser, la vitesse de coupe, la pression du gaz d’assistance est importante pour assurer l’exactitude de l’usinage et l’amélioration de la microstructure, la rugosité, la zone affectée thermiquement, la largeur de la saignée, la micro dureté et le taux d’enlèvement de matière, résultant des sollicitations mécaniques et thermiques subies durant les différentes étapes de production.Cette étude se base sur une approche empirique faisant intervenir la méthodologie des plans d’expériences (ANOVA, Taguchi), la technique de la logique floue et les méthodes de décision multicritères (FTOPSIS, GRA) pour définir d’une façon rationnelle les essais expérimentaux visant à optimiser les conditions de découpe au laser dans le but de maximiser la production en assurant une meilleure qualité de fabrication. / Laser technology has been widely used in the aeronautics industry since the 1980s. Laser cutting, as a material removal process, offers more advantages than conventional cutting processes. Among the contributions of the laser, the absence of mechanical contact with the material, a limitation of contamination of the materials and a high production due to a high cutting speed. Titanium alloys and titanium-based intermetallic composites have an important role in the field of science and engineering, making it possible to satisfy advanced manufacturing activities in the aerospace industries. Improvement of this manufacturing process is desirable to increase technical performance and economic interest. The present framework focused on study and analysis of the effects of laser beam machining parameters on the surface integrity in terms of quality and morphology of several materials, such as pure titanium, titanium alloysTi-6Al-4V and Ti6242 and the titanium-based intermetallic composite to optimize laser cutting conditions.Selection of cutting parameters in the laser machining process such as laser power, cutting speed, assist gas pressure is important to ensure machining accuracy and microstructure , roughness, heat affected zone, kerf width, microhardness and rate of removal of material improvement, resulting from the mechanical and thermal stresses undergone during the different stages of production.This study is based on an empirical approach involving the experimental design methodology (ANOVA, Taguchi), the fuzzy logic technique and the multicriteria decision methods (FTOPSIS, GRA) aiming at optimizing laser cutting conditions in order to maximize production by ensuring better manufacturing quality.

Syfte: Syftet med denna studie är att undersöka förhållandet mellan aktiesplit och överavkastning och att fastställa om en enskild investerare kan uppnå en överavkastning genom att investera i aktier noterade på OMXSPI som har genomfört en aktiesplit. Genom en genomgå av tidigare forskning samt genomförande av en egen dataanalys kommer denna studie att undersöka huruvida aktier som har genomfört en aktiesplit genererar en överavkastning jämfört med aktier som inte har genomgått en split. Teoretisk referensram: Denna studie bygger på och utmanar antagandet av den effektiva marknadshypotesen som hävdar att det inte är möjligt för en enskild investerare att uppnå överavkastning. Signalhypotesen och handelsintervallshypotesen kommer också att beaktas i undersökningen. Metod: Denna studie är av kvantitativ karaktär och använder en deduktiv ansats. Undersökningsmodellen är baserad på 131 handelsdagar som är uppdelade i fem olika eventfönster. Prisdata har samlats in för hela händelseperioden, och därefter har data bearbetats matematiskt och analyserats statistiskt. Slutsats: Resultaten från studien antyder att aktier som genomgick en aktiesplit mellan 2010 och 2022 genererade en avkastning som var 10,89% högre än aktier som inte genomgick en aktiesplit. Resultaten av studien kan bekräftas med 99% säkerhet. / Purpose: The study examines the relationship between stock splits and abnormal return, in order to investigate whether an individual investor can generate excess returns by investing in stocks listed on OMXSPI that are scheduled to undergo a split. By reviewing previous research and conducting an independent data analysis, the study will investigate whether stocks that have undergone a split generate abnormal return compared to those that have not undergone a split. Theoretical perspectives: The study builds on and challenges the efficient market hypothesis assumption that it is not possible for an individual investor to generate excess returns. The signaling hypothesis and the trading range hypothesis will also be considered. Method: The study is of a quantitative nature with a deductive approach. The research model is based on 131 trading days divided into five different events. Price data is collected for the entire event period and is mathematically calculated and analyzed statistically. Conclusions: The study's results indicate that stocks that undergo a stock split between 2010-2022 generate a 10.89% higher return than stocks that do not undergo a stock split. The results can be confirmed with a 99% level of certainty.

During the last decades, the power grid is getting rapidly digitalised in order to contribute to theestablishment of Smart Grids and evaluate efficiently the extracted bidirectional data from the powersystem infrastructure. This thesis focuses on the MV grid, since its design and operation have changedmainly because of distributed generation installations and the increased demand of information fromstakeholders. Thus, asset management constitutes a significant tool that can increase the reliability ofthe MV network’s operation and its level of control. Studies have shown that a maintenance planbased on condition monitoring of power system apparatuses would be more effective compared to theimplemented time-based scheduled maintenance.This project focuses on MV remotely controlled disconnectors since studies have shown that theirnumber of failures is double compared to manually operated ones. Since maneuverability andsecondary function are the causes of a major failure with the highest occurrence rate, motor currentmonitoring is studied in this thesis. Some devices that have the capability to monitor disconnectors’motor current, are presented. Additionally, the obtained max motor current measurements areevaluated through a parametric and a non-parametric statistical test. The main challenge of this thesisis to show whether the behaviour of motor current can be an indicator regarding to the disconnector’scondition status.Hence, the impact of different factors on the behaviour of motor current is investigated. It is concludedthat disconnectors without a failure during the studied period are more likely to have max motorcurrent measurements higher than 8A and especially in the interval [10-12]A. The difference in motorcurrent of disconnectors with a work order and without failure is more significant in 2015/2016. Itseems that under the aforementioned values of max motor current, a disconnector is more probable tohave the capability to operate properly. It is also concluded that in case of malfunction “Mellanläge”,the value of max motor current is lower than 8A with higher probability and it maybe indicates aproblem of the studied disconnector.Through the comparison in pairs, it could be concluded that the effect of the external environmentalconditions is not so high on the behaviour of disconnectors’ max motor current measurements. Incontrast, it seems that the implementation of a work order, the number of operations and if adisconnector is installed more northerly in Zone 3 play a more significant role on the behaviour of thisdisconnector’s max motor current measurements. Consequently, based on the aforementioned results itis shown that some of the investigated factors could constitute an indicator whether a disconnector ismore or less probable to have the capability to operate properly.Finally, it is calculated the reduction in the interruption cost that could be achieved in case ofimplementation of motor current monitoring on Vattenfall’s remotely controlled distributeddisconnectors. / Under de senaste årtiondena har kraftnät blivit snabbt digitaliserad För att bidra till upprättandet hosSmart Grids och effektivt utvärdera de extraherade dubbelriktade data från kraftsystemetsinfrastruktur. Denna exjobbsrapport fokuserar på MV-nätet, eftersom dess design och drift harförändrats främst på grund av distribuerade produktionsanläggningar och ökad efterfrågan påinformation från intressenter. Därför utgör ”asset management’’ ett viktigt verktyg som kan öka elnätstillförlitligheten och styrning. Studier har visat att elnäts underhåll baserad på tillståndsövervakningpå kraftsystemkomponenter skulle kunna vara effektivare jämfört med tidsbaserade schemalagdaunderhåll.Detta exjobb fokuserar på MV-fjärrstyrda frånskiljare eftersom studier har visat att deras felfrekvensär dubbelt högre jämfört med manuella. Eftersom problem i manövrerbarhet och sekundär funktionkan orsaka allvarliga fel med hög frekvens, har studien fokuserats på motorströmövervakningen idetta exjobb. Vissa produkter som har förmåga att övervaka frånskiljares motorström, presenteras.Dessutom utvärderas de maximala motorströmsmätningarna genom både parametriskt och ickeparametrisktstatistiskt test. Huvudutmaningen i denna avhandling är att utreda om motors strömmarkan vara en indikator för frånskiljares tillstånd.Olika faktorer hos motorströmmar har också undersökts. Det dras slutsatsen att frånskiljare utanmisslyckande manövern under den studerade perioden är mer benägna att ha maximalamotorströmmar högre än 8A och speciellt i intervallet [10-12] A. Skillnaden i motors strömmar hosfrånskiljare med arbetsorder och utan fel är mer signifikant under åren 2015/2016. Det verkar som attenligt ovan nämnda värden på max motorström, är en frånskiljare mer sannolikt att fungera korrekt.Det kommer också fram till att i händelse av "Mellanläge" är värdet av max motorströmmar lägre än8A med högre sannolikhet, detta kan kanske indikera ett problem hos frånskiljaren.Genom jämförelsen kan man dra slutsatsen att effekten av de yttre miljöförhållandena inte är så högpå maximala motorströmmar hos frånskiljare. Däremot verkar det som om genomförandet av enarbetsorder, antalet operationer och om en frånskiljare är installerad i zon 3 spelar en viktig roll föruppförandet av denna frånskiljares maximala motors strömmen. På grundval av det ovan nämndaresultatet framgår det att några av de undersökta faktorerna kan utgöra en indikator på att om enfrånskiljare är mer eller mindre sannolikt att ha förmågan att fungera korrekt.Slutligen visar beräkningar att minskningen av avbrottskostnaden kan uppnås vid genomförande avmotorströmövervakning på Vattenfalls fjärrstyrda distribuerade frånskiljare.

Thesis (MCur)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: Burnout is one of the challenges that nurses are faced with in their stressful and rapidly changing work environment. The vulnerability of nurses to burnout remains a major concern which affects both the individual and institution. Knowledge about burnout and associated risk factors which influence the development of burnout is vital for early recognition and intervention. The research question which guided this study was: “What are the factors influencing the degree of burnout experienced by nurses working in neonatal intensive care units?” The objectives included determining which physical, psychological, social and occupational factors influenced the degree of burnout experienced by nurses. A descriptive, explorative research design with a quantitative approach was applied. The target population consisted of (n=105) permanent nursing staff members working in the neonatal units of two different hospitals. A convenience sampling method was used. Participants (n=102) who gave voluntary consent to participate was included in the study. Validity and reliability was supported through the use of a validated questionnaire, Maslach Burnout Inventory – General Survey including a section based on demographical information and a section based on physical, psychosocial, social and occupational factors. Validity of the questionnaire was supported by the use of a research methodologist, nurse expert and a statistician in the particular field. A pilot study was done to test the feasibility of the study and to test the questionnaire for any errors and ambiguities. Ethics approval was obtained from Stellenbosch University and permission from the Heads of the hospitals where the study was conducted. The data was analyzed with the assistance of a statistician and these are presented in histograms, tables and frequencies. The relationship between response variables and nominal input variables was analysed using analysis of variance (ANOVA). Various statistical tests were applied to determine statistical associations between variables such as the Spearman test, using a 95% confidence interval. Results have shown that participants experienced an average level of emotional exhaustion, a high level of professional efficacy and a low level of cynicism. Further analyses have shown that there is a statistical significant difference between emotional exhaustion and the rank of the participant (p=<0.01), highest qualification (p=0.05) and a high workload (p=0.01). Furthermore a statistical significant difference was found between professional efficacy and rank of participants (p=<0.01). In addition a statistical significant difference was found between cynicism and the number of years participants were in the profession (p=0.05). Multiple factors were determined in this study that influences the degree of burnout nurses experience. The majority of participants (n=56/55%) experienced decreased job satisfaction and accomplishment, (n=52/51%) of participants experienced that their workload is too much for them and (n=63/62%) participants received no recognition for their work. Recommendations are based on preventative measures, because preventing burnout is easier and more cost-effective than resolving burnout once it has occurred. In conclusion, the prevention strategies, early recognition of work stress and appropriate interventions are crucial in addressing the problem of burnout. / AFRIKAANSE OPSOMMING: Uitbranding is een van die uitdagings waarmee verpleegsters te kampe het in hulle stresvolle en vinnig veranderende werkomgewing. Die kwesbaarheid van verpleegsters vir uitbranding bly ’n kritieke bekommernis wat beide die individu en die inrigting affekteer. Kennis omtrent uitbranding en verwante risiko faktore wat die ontwikkeling van uitbranding beïnvloed, is deurslaggewend vir vroeë opsporing en intervensie. Die navorsingsvraag wat hierdie studie gelei het, is: “Wat is die faktore wat die mate van uitbranding beïnvloed wat deur verpleegsters ondervind word wat in neonatale intensiewe sorgeenhede werk?” Die doelwitte wat ingesluit is, is om te bepaal watter fisiese, sielkundige, maatskaplike en beroepsfaktore die mate van uitbranding wat deur verpleegsters ervaar word, beïnvloed. ’n Beskrywende, ondersoekende navorsingsontwerp met ’n kwantitatiewe benadering is toegepas. Die teikengroep het bestaan uit (n=105) permanente verpleegpersoneel wat in die neonatale eenhede van twee verskillende hospitale werk. ’n Gerieflikheidsteekproef metode is gebruik. Deelnemers (n=102) wat vrywillige toestemming gegee het om deel te neem, is ingesluit in die navorsingstudie. Geldigheid en betroubaarheid is ondersteun deur die gebruik van ’n geldige vraelys van “Maslach Burnout Inventory – General Survey”, asook ’n afdeling gebaseer op demografiese inligting en ’n afdeling gebaseer op fisiese, sielkundige, maatskaplike en beroepsfaktore. Geldigheid van die vraelys is ondersteun deur ’n navorsingsmetodoloog, ’n verpleegspesialis en ’n statistikus op die navorsingsgebied. ’n Loodsondersoek is gedoen om die haalbaarheid van die studie te toets en om die vraelys te toets vir enige foute en dubbelsinnighede. Etiese goedkeuring is verkry van die Universiteit van Stellenbosch en goedkeuring van die Hoofde van die hospitale waar die studie uitgevoer is. Die data is geanaliseer met die hulp van ’n statistikus en is aangebied in histogramtafels en frekwensies. Die verwantskap tussen responsveranderlikes en nominale insetveranderlikes is geanaliseer deur gebruik te maak van die analise van variansie (ANOVA). Verskeie statistiese toetse is toegepas om statistiese assosiasies tussen veranderlikes te bepaal, soos deur van die Spearmantoets gebruik te maak, met ’n 95% betroubaarheidsinterval. Resultate het bewys dat deelnemers ’n gemiddelde vlak van emosionele uitputting, ’n hoë vlak van professionele effektiwiteit en ’n lae vlak van sinisme ervaar. Verdere analise het bewys dat daar ’n statistiese beduidende verskil tussen emosionele uitputting en die rang van die deelnemers (p=<0.01) is, hoogste kwalifikasie (p=0.05) en ’n hoë werklading (p=0.01). Verder is ’n statistiese beduidende verskil gevind tussen professionele effektiwiteit en rang van deelnemers (p=<0.01). Saam hiermee is ’n statistiese beduidende verskil gevind tussen siniesheid en die aantal jare wat deelnemers in die beroep is (p=0.05). Voorts, is veelvuldige faktore bepaal in hierdie studie wat die mate van uitbranding beïnvloed wat verpleegsters ervaar. Die meeste van die deelnemers (n=56/55%) het ’n afname in werksbevrediging en -verrigting ervaar, (n=52/51%) deelnemers het ervaar dat hul werklading te veel is vir hulle en (n=63/62%) deelnemers het geen erkenning vir hulle werk ontvang nie. Aanbevelings is gebaseer op voorkomende maatreëls, want om uitbranding te voorkom, is makliker en meer koste-effektief as om uitbranding te probeer oplos as dit alreeds begin het. Ten slotte, die voorkomende strategieë, vroeë identifisering van werkstres en geskikte intervensies is deurslaggewend om die probleem van uitbranding aan te spreek.