Test results from a rocket turbine test model, called the Oxidizer Technology Turbine Rig (OTTR), are discussed in this paper. The turbine was designed to support the development of advanced turbines for future liquid rocket engines. It is a highly loaded single stage liquid oxygen pump drive turbine which uses inlet and exit volutes to provide optimum performance in a compact configuration. The system design creates high pressure and temperature gradients as well as high Mach number flow. These factors make it especially difficult to accurately measure the flowfield. Test issues such as probe calibration; probe interference, rake blockage, and averaging techniques were discussed in a previous paper. Test results including inlet volute, exit volute (both circular and square), and diffuser static pressure distributions, stator airfoil static pressure distributions, total and static pressure drops through the system, and overall performance parameters at the turbine aerodynamic design point and off-design point are presented here. This thesis will mainly focus on the information of both aerodynamic design point and off-design point of inlet volute, exit volute and diffuser for both circular exit volute and square exit volute.

A zero dimensional single zone model was developed to determine the crank resoled heat release rate at various injection timings (15°-60° BTDC) and the associated uncertainties from a pilot ignited natural gas engine. The uncertainty analysis examines the percentage contribution from various sources of error, including cylinder pressure measurements, intake manifold pressure measurements, and the impact of assumptions such as constant versus temperature dependent specific heat ratios. In particular, uncertainty percentage contributions and uncertainty magnification factors were used to quantify and compare the uncertainties in heat release rates using temperature dependent specific heat ratio correlations to constant specific heat ratio assumption. It is demonstrated that the error associated with the constant specific heat ratio assumption contributes to about 40 percent error (full scale value) in the net heat release estimates in comparison to using temperature dependent specific heat ratio correlations.

Assessments of chemical health risks are performed by scientific experts. Their intended use is as bases for decisions. This thesis tries to answer the questions of how uncertainty is, and should be, communicated in such risk assessments. The thesis consists of two articles and an introductory essay. Article I focuses on the linguistic aspect of the communication of uncertainty in risk assessments. The aim of the article is to elucidate how risk assessors actually indicate uncertainty in risk assessment reports. Because of the prevalent uncertainty in risk assessment, deriving from several sources, uncertainty is communicated in verbal, rather than numerical terms. A typology of uncertainty indicators – phrases used to express uncertainty – is proposed and applied to the reviewed reports. It is found that the use of such phrases is not transparent, and the article concludes by a number of recommendations for improving the practice. Article II mainly deals with the content of the communication. The overall question treated is what a characterization of uncertainty should include if a decision made on the basis of the risk assessment information is to be as well-founded as possible. A set of conditions is put forward to be fulfilled by a characterization of uncertainty if it is to be adequate from a decision-making point of view. The greater part of the introductory essay is devoted to the concept of uncertainty which, at the conceptual level, does not appear to have been much discussed by philosophers / QC 20101208

Due to an increasing demand from decision makers for proper economic evaluations of health care services, cost-effectiveness analyses are becoming increasingly frequent. The statistic of interest in cost-effectiveness analysis is the incremental cost effectiveness ratio (ICER). When patient-specific data on costs and effects of alternative interventions is available, it can be used to quantify the uncertainty in the estimate of the ICER. Expressing this uncertainty by using confidence intervals has been recommended. However, because the statistic of interest is a ratio of two correlated random variables, its variance cannot be estimated exactly. Furthermore, the distribution of the ratio is unknown. Recently, several approximate methods have been proposed for calculating confidence intervals for the incremental cost-effectiveness ratio. These include two parametric methods: one which relies on a Taylor's Series approximation of the variance, and one based on Fieller's theorem; as well as a number of methods which rely on bootstrapping methodology. In this manuscript, these methods were applied to data obtained from a randomized clinical trial in which both health resources consumed and health outcomes were observed. Furthermore, several variations of the bootstrapping methods were proposed and applied to the same data set. Probabilities of the true ICER being in given ranges were also estimated using a bootstrapping approach. Finally, issues of sample size and power were briefly considered. The relative advantages and disadvantages of the different approaches were discussed. / Thesis / Master of Science (MS)

We propose a classification framework for the operations management literature that has looked at pricing and ordering in supply chains when supply and/or demand are uncertain. We then focus on developing three new models for managing supply and demand uncertainties in supply chains. In the first model, we study a two period sourcing problem of a firm under two sets of contracts. The contracts differ in terms of acquisition costs and the level of risk that they impose on the firm. We provide the conditions where the optimum solution is unique and also explore the behaviour of the optimum solution analytically and numerically. One application of our model is in the agribusiness supply chain and we provide numerical examples based on data from the almond industry in California. In the second model we look at a joint ordering, pricing and capacity planning problem. We characterize the optimum policy both in single and multi-period cases. In addition, we study the impact of fixed production costs on the optimum policy. The third model is devoted to coordination between a buyer and a supplier where there is a possibility of improving the supplier by both players. We analyze the problem under a Stackelberg game setting where the buyer is the leader. We show that the buyer either tries to amplify the investment of the supplier by order inflation or assumes all the investment costs. We investigate the behaviour of the optimum solution under different strategies. / Thesis / Doctor of Philosophy (PhD)

Yes / This paper uses precarity as a framework to understand the vulnerabilities experienced by those living with or caring for someone living with dementia. Drawing on qualitative interview data from the Improving the Experience of Dementia and Enhancing Active Life (IDEAL) programme, we attend to our participants' reflections on how they manage the condition and the wider circumstances in which this occurs. To interrogate the utility of precarity, we focus on our participants' descriptions of needs and challenges and set these alongside both the wider contexts in which they seek or offer care (formal and informal) and the sets of values attributed to different ways of living with dementia. Building on the work of Portacolone, our analysis identified four interconnected themes: uncertainty; experiences of support and services; independence and personhood; and cumulative pressures and concerns. We develop this analysis by reviewing how our themes reflect, extend, or depart from previously identified markers of precarity and consider the specific ways in which these markers shape the lives of those living with dementia. / ‘Improving the experience of Dementia and Enhancing Active Life: living well with dementia. The IDEAL study’ was funded jointly by the Economic and Social Research Council (ESRC) and the National Institute for Health and Care Research (NIHR) through grant ES/L001853/2. ESRC is part of UK Research and Innovation (UKRI). ‘Improving the experience of Dementia and Enhancing Active Life: a longitudinal perspective on living well with dementia. The IDEAL-2 study’ is funded by Alzheimer’s Society, grant number 348, AS-PR2-16-001.

This thesis analyzes investment incentives of strategic firms in industries where either demand is uncertain, or the good produced is economically non-storable and demand fluctuates. In those industries, investment is a long run decision, whereas production has to be adjusted short-run. Prominent examples are recently liberalized utilities such as the electricity sector. Regulated monopolies have been replaced by a small number of competing firms, which often are considered to behave strategically in order to exercise market power. Whereas the regulatory regimes prior to liberalization induced generous (over-)investment choices, we observe increasing unease of experts and policy makers regarding investment incentives in liberalized electricity markets. The first three chapters of this thesis (part one) analyze total capacity choice of strategic firms prior to producing for the spot market. We first determine the equilibrium of the market game. In the remainder of the first part we analyze the interdependency of enhanced spot market competition and firms overall capacity choice. We first analyze the impact of complete elimination of market power at the spot market giving rise to marginal cost pricing. We then consider the impact of price caps at the spot market. And finally we study the impact of reduced market power at the spot markets due to forward contracting. In the second part of the thesis firms can invest into several technologies. This allows them to determine not only their total capacity but also it's precise composition. In the absence of strategic interaction, for a single regulated firm, this has already been thoroughly analyzed in the so called peak load pricing literature, which has been widely applied for electricity markets prior to liberalization. In order to accommodate for the completely changed situation after liberalization, however, we extend this framework to the case of strategically interacting firms. Based on data of the German electricity market, we then illustrate and empirically quantify our theoretical results. We determine firms’ investment choices for different market structures and quantify the impact of spot market interventions on investment decisions and welfare. This allows us to quantify the potential for the exercise of market power, in the long run, when firms’ investment decisions are taken into account.

This study examined state-receiver apprehension and uncertainty as they relate to each other and to information seeking and confirmation of relational predictions in initial interactions.

Sustainable production and consumption have become more important internationally, which has led to the transformation of market structures and competitive situations into the direction of servitisation. This means that manufacturing companies are forced to compete through the supply of services as opposed to products. Particularly the suppliers of long-life products such as submarines and airplanes no longer simply sell these products but provide their capability or availability. Companies such as Rolls-Royce Engines achieve 60% of their revenue through selling a service rather than the engine itself. For a manufacturing company, the shift towards being a service provider means that they usually have to bid for service contracts, sometimes competitively. In the context of competitive bidding, the decision makers face various uncertainties that influence their decision. Ignoring these uncertainties or their influences can result in problems such as the generation of too little profit or even a loss or the exposure to financial risks. Raising the decision maker’s awareness of the uncertainties in the form of e.g. a decision matrix, expressing the trade-off between the probability of winning the contract and the probability of making a profit, aims at integrating these factors in the decision process. The outcome is to enable the bidding company to make a more informed decision. This was the focus of the research presented in this thesis. The aim of this research was to support the pricing decision by defining a process for modelling the influencing uncertainties and including them in a decision matrix depicting the trade-off between the probability of winning the contract and the probability of making a profit. Three empirical studies are described and the associated decision process and influencing uncertainties are discussed. Based on these studies, a conceptual framework was defined which depicts the influencing factors on a pricing decision at the bidding stage and the uncertainties within these. The framework was validated with a case study in contract bidding where the uncertainties were modelled and included in a decision matrix depicting the probability of winning the contract and the probability of making a profit. The main contributions of this research are the identification of the uncertainties influencing a pricing decision, the depiction of these in a conceptual framework, a method for ascertaining how to model these uncertainties and assessing the use of such an approach via an industrial case study.

High causally uncertain (CU) individuals experience lingering doubts about their ability to determine the causes of social events (Weary & Edwards, 1994). Furthermore, these people tend to perceive their interactions and conversational partners more negatively (Boucher & Jacobson, 2009). However, the reasons for these negative reactions remain unclear. Therefore, the purpose of the current set of studies was to explore two possible explanations for these reactions. Specifically, in three studies, I examined if insufficient uncertainty reduction or negative interpersonal expectations mediate the relationship between causal uncertainty and liking for a recent acquaintance. In Study 1 (N = 114), participants engaged in a brief unstructured dyadic conversation, whereas in Study 2 (N = 176), they engaged in three conversations with different partners. Finally, in Study 3 (N = 220), I examined the effects of temporarily activating causal uncertainty beliefs during initial interactions. As predicted, causal uncertainty was negatively associated with liking and uncertainty reduction. In Studies 1 and 2, high CU participants reported more uncertainty about themselves and their partner, and less liking than did low CU participants. Although chronic levels of causal uncertainty in Study 3 were not associated with liking or uncertainty reduction, participants who reported more current feelings of uncertainty also reported more uncertainty about themselves and their partner, and less liking. More importantly, uncertainty reduction fully mediated the effect of causal uncertainty on liking in Study 1 and partially mediated the effect of current uncertainty feelings on liking in Study 3. Therefore, high CU people’s negative social perceptions appear to stem, at least in part, from an inability to reduce their social uncertainty during initial interactions. In contrast, the relationship between causal uncertainty and interpersonal expectations remains unclear. Although causal uncertainty (as well as current uncertainty feelings) in Studies 1 and 3 were not associated with negative interpersonal expectations, high CU participants in Study 2 did report more negative expectations for their first conversation relative to low CU participants. Furthermore, although causal uncertainty was positively related to rejection sensitivity, rejection sensitivity was unable to account for the causal uncertainty effects on liking. / Thesis (Ph.D, Psychology) -- Queen's University, 2009-07-24 15:13:51.847