Master of Science

thesisThe hypersaline Great Salt Lake (GSL), located in the western United States, is divided into a north arm (Gunnison Bay) and a south arm (Gilbert Bay) by a 29-km earth-filled railroad causeway completed in 1959. Flow between the two bays is restricted to an 88-m wide breach at the western end of the causeway known as the GSL Breach. A gauging station at the GSL Breach monitors flow across the causeway. Flow across the GSL Breach is dynamic, ranging from -166 m3/s to 340 m3/s over the 5-year analysis period (2009-2013). The prominent flow direction is from south-to-north reported as positive discharge and flow from north-to-south is reported as negative discharge. Negative discharge events at the GSL Breach are referred to as flow reversal events (FRE). During the 5-year period of analysis, a total of 1510 FRE were recorded at the GSL Breach gauging station, with an average of 302 events occurring each year. Several FREs were short in duration, lasting 15-minutes or less. The longest event recorded at the GSL Breach was 1950-minutes (32.5 hours). FRE are most common when the difference between the water surface elevations of Gilbert and Gunnison Bay is at a minimum (September through December). Longer duration FRE are most common during the cool seasons (September to May) when large storm systems cross over the GSL Basin. To determine the variables influencing discharge and FREs at the GSL Breach, we applied several predictor variables to a generalized additive model (GAMs). GAMs were used to develop an effective predictive model for discharge at the GSL Breach using smoothing functions of predictor variables measured at various hydrologic and meteorological stations. We assessed the use of GAMs for accurate prediction of discharge by statistical analysis, residual plots, and time-series analysis using observed daily values at the GSL Breach gauging station. Models using wind gust, wind direction, lake elevation, and stream stage as predictor variables produce valid explanatory results for discharge at the GSL Breach. GAMs proved to be an effective method for capturing the rapid changes in discharge observed at the GSL Breach, suggesting the sensitivity of the GAM is of sufficient resolution for understanding the hydrodynamics of the GSL. To improve model accuracy, additional lake level monitoring equipment should be installed on the north and south side of the causeway and a weather station at the center of the GSL causeway is needed

LSS Implementation in Micro Enterprises: Adoption of tools to support competitiveness

LSS Implementation in Micro Enterprises: Adoption of tools to support competitiveness Seamus O’Reillya ([email protected]), Dermot Freemanb ([email protected]) and Lawrence Dooleya ([email protected]) aCork University Business School, Ireland. bDermot Freeman & Associates, Ireland Purpose This study seeks to contribute to an emerging literature addressing Lean Six Sigma (LSS) implementation in the micro enterprise context. Specifically, it explores what LSS tools address business opportunities and challenges identified by micro enterprises. Methodology This study adopts a purposive sampling approach. Thirty micro enterprise who had availed of a lean start programme launched by a public enterprise support agency were surveyed. A telephone survey followed a semi-structured interview format. This approach resulted in good participation rate and facilitated a conversation to establish motivation, initial use and impact of LSS tools and a discussion on the ongoing use of tools within these enterprises. Findings Time management and the need to improve organisational structures emerged as the main challenges faced by owner-managers. The introduction of a LSS mindset and use of tools built a new capability within these enterprises to address these challenges. The owner-managers were internally focused on structure and systems, internal process improvement and efficiency identified as main reasons to introduce LSS tools Limitations This is an exploratory survey of 30 micro enterprises. Additional observations would enhance our understanding of micro enterprise implementation of LSS. Originality While use of LSS tools by SMEs has received some attention in recent years, this is an area that merits further research. In addition, micro enterprises have received very little attention, given their specific organisational context this study focuses on these enterprises. Practical Implications The study provides practical insight into how micro enterprises may use LSS tools to improve competitiveness, in particular the benefits accruing from improved organisational structures and processes. It also suggests further research that would inform both policy makers and contribute to understanding of the potential of LSS in a micro enterprise environment. Keywords: Lean Six Sigma, micro enterprises, LSS tools, SMEs

Searching for the Effect of Immigration on the Labor Market

We compare two approaches to analyzing the effects of immigration on the labor market and find that the estimated effect of immigration on U.S. native labor outcomes depends critically on the empirical experiment used. Area analyses contrast the level or change in immigration by area with the level or change in the outcomes of non- immigrant workers. Factor proportions analyses treat immigrants as a source of increased national supply of workers of the relevant skill. Cross-section comparisons of wages and immigration in the 1980 and 1990 Censuses yield unstable results casting doubt on the validity of these calculations. Analyses of changes over time for various education groups within regions give negative estimated immigration effects, which increase in magnitude the wider the area covered. Factor proportions calculations show that immigration was somewhat important in reducing the relative pay of U.S. high school dropouts during the 1980s, while immigration and trade contributed much more modestly to the falling pay of high school equivalent workers. The different effects of immigration on native outcomes in the area and factor proportions methodologies appear to result from the diluting effect of native migration flows across regions and failure to take adequate account of other regional labor market conditions in area comparisons.

Squirrel Monkeys’ Response to Inequitable Outcomes Indicates a Behavioural Convergence Within the Primates

Although several primates respond negatively to inequity, it is unknown whether this results from homology or convergent processes. Behaviours shared within a taxonomic group are often assumed to be homologous, yet this distinction is important for a better understanding of the function of the behaviour. Previous hypotheses have linked cooperation and inequity responses. Supporting this, all species in which inequity responses have been documented are cooperative. In this study, we tested this hypothesis by investigating the response to inequity in squirrel monkeys, which share a phylogenetic Family with capuchin monkeys, but do not cooperate extensively. Subjects exchanged tokens to receive food rewards in conditions in which the level of effort required and reward received varied. Squirrel monkeys did not respond negatively to inequity. However, the monkeys were sensitive to the variation present in the task; male subjects showed a contrast effect and, as in previous studies, subjects were more sensitive to differences in reward in the context of a task than when rewards were given for free. Taken with other results, these results support the hypothesis that a negative response to inequity evolved convergently in primates, probably as a mechanism for evaluating outcomes relative to one’s partners in cooperative species

Treatment for hepatorenal syndrome in people with decompensated liver cirrhosis: a network meta-analysis

This is a protocol for a Cochrane Review (Intervention). The objectives are as follows: To compare the benefits and harms of different treatments of hepatorenal syndrome in people with decompensated liver cirrhosis

Image Restoration by Matching Gradient Distributions

The restoration of a blurry or noisy image is commonly performed with a MAP estimator, which maximizes a posterior probability to reconstruct a clean image from a degraded image. A MAP estimator, when used with a sparse gradient image prior, reconstructs piecewise smooth images and typically removes textures that are important for visual realism. We present an alternative deconvolution method called iterative distribution reweighting (IDR) which imposes a global constraint on gradients so that a reconstructed image should have a gradient distribution similar to a reference distribution. In natural images, a reference distribution not only varies from one image to another, but also within an image depending on texture. We estimate a reference distribution directly from an input image for each texture segment. Our algorithm is able to restore rich mid-frequency textures. A large-scale user study supports the conclusion that our algorithm improves the visual realism of reconstructed images compared to those of MAP estimators

Communicating personalized risks from COVID-19: guidelines from an empirical study.

As increasing amounts of data accumulate on the effects of the novel coronavirus SARS-CoV-2 and the risk factors that lead to poor outcomes, it is possible to produce personalized estimates of the risks faced by groups of people with different characteristics. The challenge of how to communicate these then becomes apparent. Based on empirical work (total n = 5520, UK) supported by in-person interviews with the public and physicians, we make recommendations on the presentation of such information. These include: using predominantly percentages when communicating the absolute risk, but also providing, for balance, a format which conveys a contrasting (higher) perception of risk (expected frequency out of 10 000); using a visual linear scale cut at an appropriate point to illustrate the maximum risk, explained through an illustrative 'persona' who might face that highest level of risk; and providing context to the absolute risk through presenting a range of other 'personas' illustrating people who would face risks of a wide range of different levels. These 'personas' should have their major risk factors (age, existing health conditions) described. By contrast, giving people absolute likelihoods of other risks they face in an attempt to add context was considered less helpful. We note that observed effect sizes generally were small. However, even small effects are meaningful and relevant when scaled up to population levels