Thesis (MScEng)--Stellenbosch University, 2012 / ENGLISH ABSTRACT: The construction project environment is dynamic and prone to change. Project change can be defined as any event that alters a project’s original scope, execution time or the cost of the works. Improper management of the projects’ changes could therefore adversely impact on the actual cost and duration of the project which may lead to project cost overruns and even claims and legal disputes. During the construction phase of a project, change affects every aspect of productivity – the planned schedules and deadlines, work methodology, resource procurement, as well as the budget and thus it could prevent the achievement of the project objectives. A project manager, therefore, wants to limit the number of change to a project. However, during a construction project there may be quite a number of changes. Managing a construction project is difficult, in that all the relevant information is rarely available at the initial stage of a project to enable one to plan and design the project accurately and make the best possible decisions. As information becomes available during the construction phase of the project, it can lead to various changes. Design errors or variations, unforeseen site conditions and vagueness in the original scope are but some of the reasons for change. No matter the size of the change, each alteration to the works has a cost, time and risk implication. Due to tight time constraints on most projects, every change requires quick, robust decision making, so as not to delay the project, which therefore results in changes not being comprehensively evaluated. Decisions are often made on intuition or experience, without an assessment of the risks involved or the influence on the cost of the project and without applying well-known project management techniques. The aim of this research was to determine what a change management process for a civil engineering project should look like, specifically the cost and risk management of changes. It investigated the current state of change management of construction projects in practice, by doing a case study and various interviews with project managers. Based on the findings of the research and the industry requirements, a model was developed for managing the costs and risks of changes. The Model was validated by means of an expert evaluation review. The change management model developed as part of this thesis can be used to analyse the cost, time and quality impact of the change, and to do a detailed risk assessment. The Model also reviews the proposed change in order to determine whether the change is necessary. It is a generic tool that can be used by engineers and their project team to enhance the management of changes that happens during the construction phase of a project for any civil construction project. / AFRIKAANSE OPSOMMING: Die konstruksie omgewing is dinamies en geneig tot verandering. Projek verandering kan gedefinieer word as enige gebeurtenis wat die projek se aanvanklike omvang verander of lei to verlenging van die tydsduur of vermeerdering van die koste van die projek. Wanbestuur van projek veranderinge kan ‘n nadelige impak op die projek kostes en tydsduur hê wat kan lei tot oorskryding van die begroting en selfs eise en regsdispute. Verandering kan elke aspek van produktiwiteit tydens die konstruksie fase van ‘n projek affekteer. Dit affekteer die beplande skedules, spertye, werk metodologie, hulpbron bestuur, asook die begroting. Dus kan dit verhoed dat die projek doelwitte bereik word. ‘n Projek bestuurder wil daarom die hoeveelheid en omvang van veranderinge beperk. ‘n Konstruksie projek kan egter heelwat veranderinge ondergaan. Om ‘n konstruksie projek te bestuur is moeilik aangesien al die relevante informasie selde beskikbaar is tydens die begin fases van ‘n projek wat nodig is om die beplanning en ontwerp van die projek so akuraat moontlik te doen en die regte besluite te neem. Soos informasie beskikbaar raak tydens die konstruksie fase van die projek, lei dit dikwels to verskeie veranderinge. Ontwerp foute of variasies, onvoorsiene terrein toestande en onduidelikheid oor die projek omvang is van die redes vir veranderinge. Ongeag die grootte van die verandering het elke wysiging tot die projek ‘n koste, tyd en riskiko implikasie. As gevolge van tydsbeperkinge vereis elke verandering vinnige en kragtige besluitneming om sodoende nie die projek te vertraag nie. Dit lei daartoe dat veranderinge nie omvattend geëvalueer word nie. Besluite word dikwels geneem op intuïsie of ervaring, sonder 'n beoordeling van die risiko's wat betrokke is of die bepaling van die invloed op die koste van die projek, en sonder die toepassing van erkende projek bestuur tegnieke. Die doel van hierdie navorsing was om vas te stel hoe 'n verandering bestuur proses moet lyk vir ‘n siviele ingenieurswese projek, spesifiek die koste en risiko bestuur van die verandering. Die huidige stand van verandering bestuur van konstruksie projekte in die praktyk is ondersoek deur middel van 'n gevallestudie en verskeie onderhoude met die projek bestuurders. 'n Model is ontwikkel vir die bestuur van die koste en risiko's van veranderinge gebaseer op die bevindinge van die navorsing en ook die vereistes van die bedryf. Die model is getoets met behulp van evaluering deur professionele ingenieurs. Die verandering bestuur model wat ontwikkel is as deel van hierdie proefskrif kan gebruik word om die koste, tyd en kwaliteit impak van ‘n verandering te analiseer, asook om 'n omvattende risiko assessering te doen. Die model hersien ook die voorgestelde verandering om te bepaal of die verandering nodig is. Dit is 'n generiese hulpmiddel wat deur ingenieurs en hul projek span gebruik kan word vir die bestuur van die veranderinge wat tydens die konstruksie fase van siviele projekte plaasvind.

<b>Background:</b> 'Competing risks' are events that either preclude or alter the probability of experiencing the primary study outcome(s). Many standard survival models fail to account for competing risks, introducing an unknown level of bias in their measures of absolute and relative risk. Individuals with type 2 diabetes mellitus (T2DM) and albuminuria are at increased risk of multiple competing causes of mortality, including cardiovascular disease (CVD), cancer and renal disease, yet studies to date have not implemented competing risks methodology. <b>Aim:</b> Using albuminuria in T2DM as a case study, this Thesis set out to quantify differences between standard- and competing-risks-adjusted survival analysis estimates of absolute and relative risk for the outcomes of cardiovascular and cancer mortality. <b>Methods:</b> 86,962 patients aged &ge;35 years with T2DM present on or before 2005 were identified in the Clinical Practice Research Datalink. To quantify differences in measures of absolute risk, cumulative risk estimates for cardiovascular and cancer mortality from standard survival analysis methods (Kaplan-Meier estimator) were compared to those from competing-risks-adjusted methods (cumulative incidence competing risk estimator). Cumulative risk estimates were stratified by patient albuminuria level (normoalbuminuria vs albuminuria). To quantify differences in measures of relative risk, estimates for the effect of albuminuria on the relative hazards of cardiovascular and cancer mortality were compared between standard cause-specific hazard (CSH) models (Cox-proportional-hazards regression), competing risk CSH models (unstratified Lunn-McNeil model), and competing risk subdistribution hazard (SDH) models (Fine-Gray model). <b>Results:</b> Patients with albuminuria, compared to those with normoalbuminuria, were older (p&LT;0.001), had higher systolic blood pressure (p&LT;0.001), had worse glycaemic control (p&LT;0.001), and were more likely to be current or ex-smokers (p&LT;0.001). Over the course of nine years of follow-up 22,512 patients died; 8,800 from CVD, 5,239 from cancer, and 8,473 from other causes. Median follow-up was 7.7 years. In patients with normoalbuminuria, nine-year standard and competing-risks-adjusted cumulative risk estimates for cardiovascular mortality were 11.1% (95% confidence interval (CI): 10.8-11.5%) and 10.2% (95% CI: 9.9-10.5%), respectively. For cancer mortality, these figures were 8.0% (95% CI: 7.7-8.3%) and 7.2% (95% CI: 6.9-7.5%). In patients with albuminuria, standard and competing-risks-adjusted estimates for cardiovascular mortality were 21.8% (95% CI: 20.9-22.7%) and 18.5% (95% CI: 17.8-19.3%), respectively. For cancer mortality, these figures were 10.7% (95% CI: 10.0-11.5%) and 8.6% (8.1-9.2%). For the effect of albuminuria on cardiovascular mortality, hazard ratios from multivariable standard CSH, competing risks CSH, and subdistribution hazard ratios from competing risks SDH models were 1.75 (95% CI: 1.63-1.87), 1.75 (95% CI: 1.64-1.87), and 1.58 (95% CI: 1.48-1.69), respectively. For the effect of albuminuria on cancer mortality, these values were 1.27 (95% CI: 1.16-1.39), 1.28 (95% CI: 1.17-1.40), and 1.11 (95% CI: 1.01-1.21). <b>Conclusions:</b> When evaluating measures of absolute risk, differences between standard and competing-risks-adjusted methods were small in absolute terms, but large in relative terms. For the investigation of epidemiological relationships using relative hazards models, standard survival analysis methods produced near-identical risk estimates to the CSH competing risks methods for the clinical associations evaluated in this Thesis. For the evaluation of risk prediction using relative hazards models, CSH models produced consistently higher risk estimates than SDH models, and their use may lead to over-estimation of the predictive effect of albuminuria on either outcome. Where outcomes are less common (like cancer) CSH models provide poor estimates of risk prediction, and SDH models should be used. This research demonstrates that differences can be present between risk estimates derived using CSH and SDH methods, and that the two are not necessarily interchangeable. Moreover, such differences may be present in other clinical areas.

Le Merapi, sur l'île indonésienne de Java, est l'un des volcans les plus actifs au monde. Ses pentes sont densément habitées jusqu'à un rayon de 4 km autour du sommet, et plus de 50 000 personnes vivent dans la zone la plus dangereuse (KRB III), exposée aux coulées et déferlantes pyroclastiques, un des aléas volcaniques les plus meurtriers. Dans ce contexte, l'évacuation temporaire des zones menacées est, en cas d'éruption, le seul moyen envisageable de réduction du risque pour les populations. L'objectif de cette thèse est d'analyser les réponses institutionnelles et communautaires déployées face aux crises volcaniques au Merapi, en particulier lors de l'éruption majeure de 2010. L'évaluation de ces réponses et des capacités de gestion de crise repose sur des retours d'expérience d'éruptions récentes, surtout celle de 2010, dont le vécu a permis de recueillir des données de première main sous forme de questionnaires, entretiens, discussions de groupe et maquette participative en trois dimensions. Les résultats présentés portent dans un premier temps sur l'analyse des facteurs de toutes natures (socioéconomiques, politiques, culturels, fonctionnels, etc.) susceptibles d'influencer la décision d'évacuer et le déroulement des évacuations, en nous fondant notamment sur des analyses rétrospectives sur les éruptions de 1994 et 2006. Dans un second temps, nous décortiquons la gestion de crise et en particulier le processus d'évacuation lors de l'éruption de 2010. Dans un dernier temps, cette thèse propose des modélisations d'évacuation à deux échelles: celle du massif volcanique et celle d'une localité, ceci dans une démarche prospective. Ces analyses permettent au final de mettre en évidence les lacunes dans la gestion des évacuations lors des crises volcaniques en Indonésie, et de proposer des améliorations pour une meilleure préparation aux niveaux institutionnel et communautaire. / Merapi volcano, located in the Java Island, Indonesia, is one of the world's most active volcanoes. Its slopes are densely populated until a 4 km radius around the summit. More than 50,000 people living in the most dangerous area (KRB III) are exposed to pyroclastic density currents (PDCs), one of the deadliest volcanic hazards. ln this context, temporary evacuation of the threatened zone, during eruption, is the only possible way to reduce the risk of population. The objective of this thesis is to analyze the institutional and community responses in coping with volcanic crises, especially during the 2010 major eruption of Merapi. An evaluation of these responses and capacities of crisis management was done based on the lessons learned from recent eruptions, especially the 2010. First-hand data were obtained using questionnaires, interviews, focus group discussions and participatory three-dimensional map. In the first place, the results of this thesis were built upon the analysis of the factors influencing evacuation decision and the evacuation process, notably based on the 1994 and 2006 eruptions. Secondly, we studied the cri sis management and, in particular, the evacuation process during the 2010 eruption. Finally, we conducted evacuation modeling, in a term of forward-looking approach, at two scales: on the entire volcano and local level. This analysis highlights the gaps in evacuation management during volcanic crisis in Indonesia and suggests improvements for better preparation for institutional and community levels.

Cette étude porte sur le mouvement non conventionnel en oncologie et tend à évaluer l’impact des MCA conjointement en termes de bénéfices, de risques et de dérives chez les patients atteints de cancer. Notre démarche comparative explore le vécu de 32 patients utilisant ou non les MCA, de façon complémentaire ou alternative aux traitements curatifs. Un entretien semi-directif unique a été mené auprès de chaque patient dans l’objectif d’identifier les processus communs et distincts entre les différents groupes. Un livret de questionnaire leur a également été remis afin de rendre compte des caractéristiques du mouvement hétérodoxe. L’analyse du discours révèle que le recours aux MCA influence positivement le vécu de la maladie sur l’ensemble des dimensions de la personne, mais détériore la représentation de la médecine allopathique et la relation soignant/soigné. Le refus de traitements curatifs chez les utilisateurs de MCA est lié à un univers de croyances invalidantes qu’ils développent. L’analyse des échelles suggère que le recours aux MCA améliore la perception de la santé globale, réduit la symptomatologie dépressive, mais reste sans effet sur l’anxiété. Le recours alternatif aux MCA est lié aux croyances d’attribution causale interne et de contrôle religieux, mais pas à celle d’un contrôle sur l’évolution de la maladie. L’intégration des MCA en oncologie apparaît pertinente et nécessaire pour améliorer la prise en charge des malades, mais doit pouvoir se déployer avec prudence et de façon progressive au regard des risques et des dérives de certaines pratiques hétérodoxes. / This study examines the unconventional movement in Oncology and aim to assess the impact of CAM jointly in terms of benefits, of risks and derivatives in patients with cancer.Our comparative approach explores the experience of 32 patients using or not the CAM of complementary or alternative to curative treatments. A unique semi directive interview was conducted with each patient in order to identify common and distinct processes between differents groups. A questionnaire booklet was also been handed them to end to account characteristics of the unconventional movement.Analysis of the speech shows that the use of CAM affects positively the experience of the illness across the dimensions of the person, but deteriorates the representation of allopathic medicine and the patient-caregiver relationship. The refusal of curative treatments among users of CAM is linked to a universe of disabling beliefs they develop.The analysis of scales suggests that the use of CAM improves the perception of global health, reduces the depressive symptomatology, but has no effect on anxiety. The alternative use of CAM is related to internal causal attribution and control beliefs, but not to control over the course of the disease. The integration of CAM in oncology appears relevant and necessary to improve the care of patients, but should be able to be deployed with caution and progressively in the light of the risks and derivatives of certain heterodox practices.

The target of the thesis was to evaluate the risk of chemical harmful substances and dust in the working air of metal production. Four research questions were asked: {\clqq}What harmful substances are fixed in the working environment of the metal production?`` {\clqq}Are the hygienic limits of chemical substances and dust in the working environment of metal production observed?``, {\clqq}What measures were taken by the employer for the purpose of the health protection of employees?`` and {\clqq}Are the measures taken by the employer for the purpose of the health protection of employees effective?`` The thesis was treated as qualitative research. The followed file consisted of three South Bohemian companies dealing with metal production. The method of the direct, non participating and clear observation was applied for the data collection, moreover the study of documents {--} testing reports. The secondary analysis of data was performed. The results of measuring were compared with the hygienic limits fixed by the Directive of government No. 361/2007 Coll.. The evaluated professions were divided in categories pursuant the Directive No. 432/2003 Coll. In the working air of metal production, the concentration of the total dust, chromium, hexavalent chromium, carbon monoxide and ozone were followed. The last measuring in the monitored workshops proved that the hygienic limits were observed, except for two cases when the highest acceptable concentration determined for chromium and the chromium (II,III) compounds as Cr, and of the hygienic limit for welding fumes were exceeded. The most important protective measure applied by the employers on their workplaces was the reconstruction of air-conditioning, or installation of local exhausting. In view of the gradual decrease of the harmful substance in the working air in connection to the taken measures may be stated that the given measures were effective. The hypothesis {\clqq}Modernisation of operations in metal production improves the working environment of employees and in the modern operations no above-the-limit values of the most monitored harmful substances were found out. ``

Les événements extrêmes ont un impact important sur les distributions de rendement et les décisions d’investissement. Cependant, le rôle des risques d’événement est sous-estimé dans les approches populaires de prise de décision financière. Cette thèse inclut les risques d’événements dans les décisions d’investissement pour améliorer l’optimalité globale des investissements. Nous examinons les risques d’événements dans deux contextes financiers différents mais cohérents: la sélection de portefeuilles et le financement d’entreprise. Dans le cadre de la sélection de portefeuilles, nous nous concentrons sur l’incorporation d’informations d’ordre supérieur pour capturer l’impact des risques d’événements sur la construction du portefeuille. Des extensions d’ordre supérieur sont implémentées sur deux méthodes principales d’optimisation de portefeuille: le cadre classique de l’optimisation de la variance moyenne et du CAPM, et l’approche de la dominance stochastique. Nous trouvons que l’inclusion d’informations d’ordre supérieur améliore l’optimalité globale du portefeuille compte tenu de la présence de risques d’événement. Dans un cas particulier, nous combinons les applications traditionnelles de l’optimisation de la moyenne variance et de l’analyse de dominance stochastique pour examiner l’efficacité de l’indice de DJIA. Nous trouvons que DJIA est efficace en tant que référence de performance. Dans le domaine des finances d’entreprise, nous avons principalement identifié les changements de dénomination sociale de M&A parmi l’indice S&P 500 et examiné comment les événements de changement de nom affectent les modèles de rendement pour les acquéreurs et les cibles. Dans le cadre de cette étude d’entreprise, nous montrons que les changements de nom affectent sensiblement la dynamique du rendement et que la différence de rendement anormale entre les événements de changement de nom et les événements sans changementde nom est économiquement et statistiquement significative. En général, nos études montrent que l’inclusion des risques d’événements dans les processus décisionnels apporte des avantages importants à l’optimisation de l’allocation des actifs. / Extreme events have a material impact on return distributions and investment decisions. However, the role of event risks is understated in popular financial decision making approaches. This thesis includes event risks into investment decisions to improve global investment optimality. We examine event risks in two different but coherent financial settings: portfolio selection and corporate finance. In the portfolio selection setting, we focus on the incorporation of higher order information to capture the impact of event risks on portfolio construction. Higher order extensions are implemented on two main portfolio optimization methods: the classic framework of mean variance optimization and CAPM, and the stochastic dominance approach. We find that the inclusion of higher order information improves global portfolio optimality given the presence of event risks. As a special case, we combine the traditional applications of mean variance optimization and stochastic dominance analysis to examine the index efficiency of DJIA. We find that DJIA is efficient as a performance benchmark. In the corporate finance setting, we principally identified corporate name changes of M&As among the S&P 500 index, and examined how the name change events impact the return patterns for the acquirers and the targets. Conducting this corporate event study, we show that name changeevents substantially affect return dynamics, and that the abnormal return difference between name change events and non name change events is economically and statistically significant. Generally, our studies illustrate that the inclusion of event risks in decision processes brings important benefits to the asset allocation optimization.

This research examines the impact of certain bank-specific variables on bank stability in Ghana, in the context of the existing regulatory structures. The thesis examines this issue along two main themes. The first part of this study examines whether two of the commonly used measures of banking stability, the CAMELS and the Z-Score, provide similar or different results in assessing the stability of banks in Ghana. The results of this study show that the use of the CAMELS and the Z-score measures could lead to different outcomes in terms of bank stability in Ghana. This suggests that the traditional micro-prudential CAMELS framework should be complemented with the Z-score which inherently has both micro and macro-prudential characteristics of signaling weaknesses in bank stability, and to enhance the management of bank stability. The second part of the study examines the impact of some bank-specific variables on bank stability. Using the panel data approach, the results show that while bank size, regulatory governance, regulatory independence and origin impact significantly on the stability score, there was no significant impact in terms of interbank borrowing and non-performing loans. Further analysis using the Blinder –Oaxaca decomposition also suggests that foreign banks in Ghana exhibit relatively higher levels of stability compared to local banks. The policy implications of these findings suggest that the liberalisation of the banking sector should be accompanied by an effective micro- and macro-prudential supervisory regime in order to manage the stability of the constituent banks and the banking sector as a whole.

Dans les régions de montagne, la prévision des évènements gravitaires reste un défi pour la gestion des risques. Des méthodes de calcul telles que la méthode des éléments discrets (DEM), où les particules interagissent les unes avec les autres pour restituer un comportement global d’une masse granulaire, ont été utilisées pour aborder ce type de problématique. L’application de la DEM reste normalement limitée aux évènements de petits volumes impliquant un nombre de blocs plutôt faible, puisque les temps de calcul peuvent devenir rapidement prohibitifs avec l’augmentation du nombre de particules. Les méthodes de calcul continues sont donc une alternative intéressante car elles permettent de réduire les temps de calcul. Elles nécessitent cependant la définition d’une loi de comportement macroscopique capable de représenter correctement les principaux traits de comportement mécanique du matériau au sein de la masse. L'objectif principal du travail de thèse réside dans le développement d’un outil numérique permettant de modéliser certains aléas gravitaires tels que les écoulements en masse. Notre choix s’est porté sur une méthode Lagrangienne-Eulérienne (méthode des points matériels – MPM) capable de gérer de grandes déformations tout en bénéficiant des principaux avantages de la méthode des éléments finis (FEM). La méthode utilise une grille Eulérienne fixe sur laquelle se déplacent des points matériels pendant les simulations. Un outil numérique, nommé MPMbox (2D et 3D), a été développé entièrement durant la thèse en C++. Le code a été validé à l'aide d'une série de solutions analytiques en quasi-statique (tests géotechniques standards) ainsi que par des applications de la littérature incluant des déformations importantes et rapides (tests d'affaissement). Après validation, le code a été confronté aux prédictions d’un outil de calcul DEM (DEMbox) dans le cadre de simulations numériques impliquant l'écoulement (initiation, régimes transitoires, propagation et arrêt) d'un matériau granulaire (particules sphero-polyhédriques) sur un plan incliné. Les résultats ont été comparés en termes de distance de propagation, de forme du dépôt et d'énergies dissipées à l'interface et dans la masse pendant l'écoulement. Pour les applications qui ont suivies, des éléments discrets ont été couplés à la MPM afin qu'un bloc rigide (DEM) puisse interagir avec un sol déformable (MPM). Cette application a consisté en l'analyse (2D) de la collision entre un bloc rocheux rigide (rond ou carré) et un sol bicouche élastoplastique. Les investigations ont été largement basées sur la mesure de coefficients de restitution (rapport des énergies cinétiques avant et après impact) qui reste difficile à déterminer expérimentalement. / In mountainous regions, the prediction of gravitational phenomena remains a challenge for the management of risk. Computational methods such as the Discrete Element Method (DEM) have been used for the modeling of these types of phenomena, where particles interact with each other to give an overall behavior of the mass. Its application can be somewhat restricted to small and medium number of blocks, since the computational time can easily become too large. Continuum analyses are therefore an attractive approach, which can reduce the computational times, but that rely on a constitutive law to represent the behavior within the mass. The main objective of this PhD was to develop a numerical tool that allowed the modeling of some specific gravitational hazards, such as the flowing of mass. A Lagrangian-Eulerian method such as the Material Point Method (MPM) is able to handle large deformations, while preserving most of the capabilities of the Finite Element Method (FEM). The method uses an Eulerian grid which is only used as a numerical scratch-pad, and remains fixed during simulations. A numerical tool named MPMbox (2D and 3D) was then developed from the ground up using C++. The code was validated using a series of analytical solutions for quasi-static analysis (some standard geotechnical tests), as well as simulations including large and rather rapid deformations (slump tests). After validation, the code was first used to make a numerical comparison with the DEM. In the comparison, a parametric survey was carried out during which the flow of a granular material on a sloped surface was simulated. Results were compared in terms of run-out distance, spread of the deposit and energy dissipated at the interface and within the mass during the flow. For a second study, discrete elements were coupled with MPM so that a rigid block could interact with a deformable soil. This application consisted in the (2D) analysis of the collision between a discrete block (round and squared) and a bounded elasto-plastic double-layered soil (soft over hard layers). The investigations were largely based on the measurement of the restitution coefficient (ratio of kinetic energies before to after the impact), which cannot be easily determined experimentally.

[pt] A última etapa do sequestro e armazenamento de carbono (CCS) pode ser realizada pela de injeção de CO2 em reservatórios geológicos. Projetos de CCS fazem parte de uma série de técnicas para a mitigação dos gases do efeito estufa. Neste trabalho, uma metodologia semi-quantitativa para avaliação do risco da injeção de CO2 em reservatórios geológicos é apresentada. Essa metodologia é desenvolvida a partir da criação e utilização de uma matriz de risco. Essa matriz possui em uma direção categorias de severidade ajustadas de forma qualitativa e na outra direção categorias de probabilidade ajustadas a partir de análises probabilísticas. Os valores de risco de uma fonte de perigo são calculados pelo produto de suas severidades com suas probabilidades associadas. As fontes de perigo são problemas relacionados à injeção de CO2 que são selecionadas para análise de um cenário específico. As categorias de severidade são definidas por faixas de níveis de funcionamento de uma fonte de perigo. Diversos métodos de análise probabilística são investigados e a família de métodos do valor médio apresenta características favoráveis ao seu emprego em funções de estado limite complexas. A metodologia é aplicada em um estudo de caso ilustrativo. Com os valores de risco resultantes, faz-se a identificação da principal fonte de perigo e das variáveis aleatórias mais influentes. A avaliação da metodologia indica que ela é uma ferramenta poderosa para os analistas e tomadores de decisão, e tem potencial para auxiliar na fase de planejamento de projetos de CCS. / [en] The last stage of carbon capture and sequestration (CCS) can be performed by CO2 injection process in geological reservoirs. CCS projects belong to a number of ways to mitigate greenhouse gases. In this work, a semi-quantitative methodology to assess the risk of CO2 injection in geological reservoirs is developed. This methodology is based on the establishment and application of a risk matrix. This matrix has in one direction severity categories set in a qualitative way and in the other direction probability categories set from probabilistic analysis. The risk values of a hazard source are calculated by the product of their severities with their associated probabilities. Hazard sources are problems related to the injection of CO2 that are selected for a specific scenario analysis. The severity categories are defined by operating level ranges of a hazard source. Several probabilistic analysis methods are investigated and the family of the mean value methods shows characteristics favoring their use in complex limit state functions.The methodology is applied in an illustrative case study. With the resulting risk values, the identification of the main hazard source and the most inuential random variables are made. Assessment of the methodology indicates that it is a powerful tool for analysts and decision makers, and it has the potential to assist in the CCS project planning phase.

Molntjänster har redan tagit över flera branscher och sjukvården står näst på tur. Molntjänsters effektiviseringar lockar sjukvården som är en hård pressad bransch både inom kompetens och tid. Samtidigt ansvarar sjukvården över patientdata vilket leder till att de har strikta lagar och regelverk att följa som innebär stora utmaningar. Det kan vara svårt att få en holistisk bild av vad molntjänster kan erbjuda sjukvårdsorganisationen och därför har vårdens syn på molntjänster undersökts och vilka faktorer som präglat deras hantering av patientdata i molnet. En kvalitativ studie har genomförts och där respondenter som är IT-ansvariga både på sjukvårdsorganisationer och molnleverantörer har intervjuats. Sammanfattningsvis dras slutsatsen att i IT-ansvariga på sjukvårdsorganisationer ser molntjänster som en möjlighet och en väg som de måste tas. För att kunna möta patienters behov är de överens om att sjukvården kommer behöva möta deras patienter på en digital plattform och att det krävs tydliga gemensamma riktlinjer för hur man som sjukhusorganisation bör agera vid beslutstagande av molntjänster från en molnleverantör. Det är av intresse att en myndighet upprättas för att ta fram dessa lagar och riktlinjer i syfte att vara rådgivare och inte granskande. Slutligen presenteras sex stycken punkter, som enligt respondenterna, präglar hantering av patientdata i molntjänster som är riktade till de beslutsfattande och IT-ansvariga som är involverade i de beslut som ska fattas kring användandet av molntjänster inom sjukvårdsorganisationer.