Three Essays on Intensive Care Unit Capacity Planning

The Intensive Care Unit (ICU) is a resource-intensive, costly environment. Data gathered from patients during their stay in the ICU has traditionally been used for clinical purposes, but can have a significant impact on healthcare capacity planning and patient flow. There is a need to study how metrics collected in Canadian ICUs, such as the Multiple Organ Dysfunction Syndrome (MODS) score and the Nine Equivalents of Nursing Manpower Use Score (NEMS) can be used to improve capacity planning decisions. Using discrete-event simulation, statistical, survival and machine learning models, I have built long- and short-term capacity planning models to help hospital administrators better manage patient flows in the ICU. This dissertation consists of three essays that explore the use of these metrics in ICU capacity planning. In the first essay, I study the incorporation of the nursing manpower score NEMS into a discrete-event simulation model to estimate optimal long-term capacity levels of critical care beds in both Level 3 (ICU) and Level 2 (step-down) units. Using data from London Health Sciences Centre (LHSC) University Hospital, I demonstrate the benefits of simulating patients’ daily NEMS changes as triggers for transfer to a step-down unit. This essay also examines ways in which transfer to a step-down unit may improve patient length of stay (LOS), flow and costs. In the second essay, I demonstrate that the ICU LOS literature shows the predominance of multiple linear regression models for individual patients’ ICU LOS and outcome predictions (e.g., death, discharge, long stay). Using data from LHSC’s two ICUs, I compare the performances of well known statistical models with contemporary supervised machine learning models in predicting such outcomes. I show that there is no dominant model in terms of individual patients’ LOS predictions, but that outcome prediction (death, discharge, long stay) performance can be improved by using supervised machine learning techniques. In the third essay, I build on the use of NEMS to simulate realistic ICU LOS for long term capacity planning, and on the use of NEMS and MODS to predict individual ICU LOS in order to improve short-term capacity planning. First, I fit a parametric survival model called the Accelerated Failure Time (Weibull AFT) model with LHSC’s UH data. Then I analyze the model’s hazard rates, event time ratios and LOS, both at the time of the patient’s arrival in the ii ICU and after 3 days’ stay. Finally, I generate daily patient survival probabilities and pool them to predict future expected ICU occupancy rates. Using survival probability pooling for short term capacity planning is a novel use of the ATF model, and may be used to accurately predict ICU occupancy

Graduate Recital: Felipe Rodrigues

Kemp Recital HallApril 16, 2016Saturday Afternoon5:00 p.m

Inconstitucionalidade do fundamento da garantia da ordem pública para decretação da prisão preventiva

TCC(graduação) - Universidade Federal de Santa Catarina. Centro de Ciências Jurídicas. Direito.O processo penal pode ser visto como um caminho que deve ser percorrido para que o Direito Penal seja aplicado, quer dizer, possui um caráter instrumental em relação a este. Constitui uma limitação ao poder de punir do Estado. Serve também para dar efetividade às garantias constitucionais. Qualquer medida adotada no trâmite do processo que não tenha relação com suas finalidades é de constitucionalidade questionável. Com o advento da Lei n. 12.403/2011, foram instituídas medidas cautelares diversas da prisão. Para que sejam decretadas, essas medidas devem cumprir determinados requisitos. Para que a prisão preventiva, espécie do gênero medidas cautelares, seja decretada, além de cumprir os requisitos, deve estar de acordo também com certos pressupostos e fundamentos previstos no Código de Processo Penal. Os requisitos podem ser entendidos como o fumus commissi delicti e periculum libertatis, apesar de parte da doutrina chamá-los de fumus boni iuris e periculum in mora. Os pressupostos se encontram no artigo 313 do Código de Processo Penal, enquanto os fundamentos são aqueles elencados no artigo 312. Estes são: garantia da ordem pública, garantia da ordem econômica, conveniência da instrução criminal e asseguração da aplicação da lei penal. A expressão “garantia da ordem pública” pode ser entendida de diversas formas. O fundamento da garantia da ordem econômica normalmente é utilizado quando se trata de crimes relacionados com o sistema financeiro. Nenhum desses fundamentos (garantia da ordem pública e da ordem econômica) possui natureza cautelar. Conveniência da instrução criminal é eminentemente cautelar, mas deve haver real necessidade para que a prisão preventiva seja decretada com base nesse fundamento. Asseguração da aplicação da lei penal também é cautelar. Esse fundamento é utilizado quando o acusado tenta se furtar à aplicação da lei. A expressão “garantia da ordem pública” possui variadas definições. Eventualmente é utilizada fazendo alusão à crueldade do delito, ao clamor social, à proteção do acusado, à credibilidade das instituições ou da Justiça, ao risco de reiteração delitiva, entre outros. Esse fundamento não possui natureza cautelar e é demasiadamente abstrato, sendo, portanto, inconstitucional

Novel Axisymmetric Diffusion Bonded Recuperator for Gas Turbines

The small gas turbines systems, arbitrary categorized as microturbines (5-200 kW) and miniturbines (200-500 kW) are the current most economical solution for the distributed power generation market. The thermal efficiency of such microturbines without and with a recuperator is about 20 and 40% respectively, thus a recuperator is mandatory to reach higher cycle efficiencies. However, the recuperator accounts for about 25-30% of the turbine total cost and its temperature and pressure are constrained depending on the material and construction method, being the bottleneck of the improvement and advancement of this kind of power generation plant. Thus, the actual focus is to develop high performance recuperators able to withstand high temperatures and pressure at minimum cost. There are several different recuperators present on the market, each with their own heat transfer surface and manufacturing method, but all present drawbacks and are relatively old compared to the actual manufacturing methods. For instance, the rectangular offset strip fin geometry, which is one of the highest performance surfaces, is expensive to manufacture and weak to withstand temperature and pressure due to brazing requirements. Hence, in this thesis, a completely novel modular axisymmetric recuperator concept is proposed, joined by diffusion bonding technique, one of the current most advanced heat exchanger manufacturing methods. For the recuperator core, a novel heat transfer surface is proposed based in the rectangular offset strip fins, the thermal and hydraulic characteristics of which were determined experimentally. The devised heat transfer and pressure drop correlations show 85% agreement with the experimental data in the range of 500<3000. A code for the recuperator design, using entropy generation minimization, was developed to predict the recuperator performance and size the optimum recuperator core dimensions. The design code was validated with CFD which in turn was validated with experimental data. The heat transfer and pressure drop CFD results agreed the experimental data with deviation within 3.2% and 27.7%, respectively, and the design code agreed the CFD results with deviation within 0.9% and 11.9%, respectively. Four recuperator study cases for different turbine sizes, 100kW, 100kW_beta, 1250kW and 5000kW, were designed using the design code. The results show the proposed concept can achieve high effectiveness (~90%) with low pressure drop (<4%) with a volume compatible with the current recuperators. Furthermore, the novel recuperator concept has a list of advantages, which makes attractive its application on the future gas turbines, encouraging the research continuity of the proposed concept

Modeling the influence of eucalypt plantation on wildfire occurrence in the Brazilian savanna biome

In the last decades, eucalypt plantations are expanding across the Brazilian savanna, one of the most frequently burned ecosystems in the world. Wildfires are one of the main threats to forest plantations, causing economic and environmental loss. Modeling wildfire occurrence provides a better understanding of the processes that drive fire activity. Furthermore, the use of spatially explicit models may promote more effective management strategies and support fire prevention policies. In this work, we assessed wildfire occurrence combining Random Forest (RF) algorithms and cluster analysis to predict and detect changes in the spatial pattern of ignition probability over time. The model was trained using several explanatory drivers related to fire ignition: accessibility, proximity to agricultural lands or human activities, among others. Specifically, we introduced the progression of eucalypt plantations on a two-year basis to capture the influence of land cover changes over fire likelihood consistently. Fire occurrences in the period 2010–2016 were retrieved from the Brazilian Institute of Space Research (INPE) database. In terms of the AUC (area under the Receiver Operating Characteristic curve), the model denoted fairly good predictive accuracy (AUC ≈ 0.72). Results suggested that fire occurrence was mainly linked to proximity agricultural and to urban interfaces. Eucalypt plantation contributed to increased wildfire likelihood and denoted fairly high importance as an explanatory variable (17% increase of Mean Square Error [MSE]). Nevertheless, agriculture and urban interfaces proved to be the main drivers, contributing to decreasing the RF’s MSE in 42% and 38%, respectively. Furthermore, eucalypt plantations expansion is progressing over clusters of high wildfire likelihood, thus increasing the exposure to wildfire events for young eucalypt plantations and nearby areas. Protective measures should be focus on in the mapped Hot Spot zones in order to mitigate the exposure to fire events and to contribute for an efficient initial suppression rather than costly firefighting.This research was funded by the Erasmus+ Programme student scholarship (grant to Luiz Felipe de Castro Galizia). This work has been financed by the Ministerio de Economía y Competitividad; is a postdoctoral ‘Juan de la Cierva Formación’ research grant awarded by Marcos Rodrigues (FJCI-2016-31090)

Os tons do medo: fotoetnografia nas ruas de Porto Alegre (RS, Brasil)

This photographic narrative arises from researches on the images of fears and crises in urban context’s everyday life developed in the field of the projects on visual anthropology (NAVISUAL) and image’s bank (BIEV) on the Programa de Pós-Graduação em Antropologia Social in Universidade Federal do Rio Grande do Sul (Eckert e Rocha, 2013). These are images that evoke, in a critical perspective, the processes of discontinuities and disruptions to the human duration’s projects and continuity on the anthropological path (Bachelard, 1984, 1989, Durand, 1988).Esta narrativa fotográfica resulta de pesquisas sobre as imagens dos medos e das crises na vida cotidiana em contexto urbanos desenvolvidas no âmbito dos projetos de antropologia visual (NAVISUAL) e banco de imagens (BIEV) no Programa de Pós-Graduação em Antropologia Social na Universidade Federal do Rio Grande do Sul (Eckert e Rocha, 2013). São imagens que evocam, em uma perspectiva crítica, os processos de descontinuidades e rupturas aos projetos humanos de duração e continuidade no trajeto antropológico (Bachelard, 1984, 1989, Durand, 1988)