Master of Science

thesisWhile it is well accepted that modeling of vegetation in urban areas is important for simulating urban microclimate, most well-known urban models have neglected vegetation, particularly explicit modeling of vegetation elements such as trees. In this study, we quantitatively evaluate mean wind fields generated using the building-resolving Quick Urban Industrial Complex wind model (QUIC-URB) for an urban domain containing a high vegetation fraction, including a large number of trees. A new vegetation model that has both theoretical and empirical features is developed. The performance of this new vegetation model is compared with published wind-tunnel data available in literature and the results show less than 15% relative deviations. Further evaluation is done using mean wind data from a suite of eleven low-cost weather stations that were distributed throughout the University of Utah campus during a 2-year period, from 2015 to 2017. Results are presented for simulations with and without vegetation using different configurations of QUIC's standard canopy vegetation model as well as the newly developed isolated tree model. Preliminary modeling results indicate underestimation of wind speeds in the upwind cavity and building wake zones. However, the outcomes of the newly developed model are in a good agreement with the observed experimental trends in wide open areas and street-canyon regions

Effects of Cooking and Chill-Reheating On Lipid and Flavor Characteristics Of S. Commerson and S. Guttatus

The cook-chill-reheating of foods are becoming more important in the catering industry today. However, reports on the potential changes on the nutrients such as lipid characteristics are negligible. Therefore, the objectives of the study were to determine the effect of cook-chill-reheating on the lipid characteristics, fatty acid composition and also flavor characteristics of the fish fillets. The lipid content, chemical characteristics i.e. free fatty acid (FFA), peroxide value (PV), iodine value (IV) and Thiobarbituric acid value (TBA), fatty acid composition, flavor profile, phospholipids and triglycerides content were determined in the raw and cooked and chilled-reheated samples. The sequential effect of cook-chill-reheating on the lipid and flavor characteristics in ‘Tenggiri batang’ (Scomberomorous commerson Lacepede, 1800) and ‘Tenggiri papan’ (S. guttatus Bloch and Schneider, 1801) fillets were studied. Cooked samples (by microwave, grilling, steaming and shallow fat frying) were chilled (4 ± 2 ºC) and then reheated using a microwave oven after 2 days. A two months frozen (-18 ºC) storage of raw material was studied to evaluate the effects of frozen storage on lipid characteristics prior to cooking. One and two way analysis of variance test (ANOVA) were used to analyze the effect of cooking by the afore mentioned methods and the two way ANOVA was used to analyze the effect of chill-reheating on the cooked samples. Principle components analysis (PCA) was used for visualizing and reducing the data. The lipid characteristics did not change significantly during the first two weeks of frozen storage. Cooking and reheating by the different methods significantly (P<0.05) changed the FFA, PV and TBA content in both fish. The initial lipid content of S. commerson (2.3%), significantly changed to 4.0, 2.6, 3.6 and 4.8 % after microwave cooking, grilling, steaming and shallow fat frying; and for S. guttatus the initial lipid content of 6.0% changed to 7.0, 10.5, 5.4 and 10.3 %, respectively. Significant increase in lipid content were observed in steamed samples after reheating in both fish, and in grilled and fried samples of S. commerson. Both cooking and chilling-reheating affected (P<0.05) the fatty acid composition. Higher concentrations of C16:0, C18:1 n-9 c and C18:2 n-6 c were observed in shallow fat fried samples. Frying significantly increased the amount of n-6 FAs in both fish. Reheating caused a slight increase in the amount of SFA / PUFA and also the n-6/ n-3 ratio in all cooked samples. The C22:6/C16:0 ratio decreased in all cooked and reheated samples. Alkanes-alkenes were the major group of volatile compounds of raw samples in both fish. Cooking generated new compounds and increased the concentration of volatile component from 72.8 to 111.1, 74.3, 112.2 and 92.4 μg/kg for S. commerson and from 63.6 to 67.4, 77.80, 65.8 and 67.1 μg/kg for S. guttatus after microwave cooking, grilling, steaming and frying, respectively. Reheating also caused changes in the number and the concentration of the volatile compounds. In S. commerson, only shallow fat frying significantly increased the TG content. In S. guttatus there were no significant changes in the triglycerides and phospholipids content in the cooked samples. Slight increase in the amount of TG content was detected in all cooked samples of S. commerson during chill-reheating. The TG content of microwave cooked and steamed samples of S. guttatus, slightly decreased after chill-reheating

DETERMINISTICALLY-MODIFIED INTEGRAL ESTIMATORS OF GRAVITATIONAL TENSOR

The Earth’s global gravity field modelling is an important subject in Physical Geodesy. For this purpose different satellite gravimetry missions have been designed and launched. Satellite gravity gradiometry (SGG) is a technique to measure the second-order derivatives of the gravity field. The gravity field and steady state ocean circulation explorer (GOCE) is the first satellite mission which uses this technique and is dedicated to recover Earth’s gravity models (EGMs) up to medium wavelengths. The existing terrestrial gravimetric data and EGM scan be used for validation of the GOCE data prior to their use. In this research, the tensor of gravitation in the local north-oriented frame is generated using deterministically-modified integral estimators involving terrestrial data and EGMs. The paper presents that the SGG data is assessable with an accuracy of 1-2 mE in Fennoscandia using a modified integral estimatorby the Molodensky method. A degree of modification of 100 and an integration cap size of 2.5° for integrating 5´x5´ terrestrial data are proper parameters for the estimator

Increasing the Efficiency of Policy Learning for Autonomous Vehicles by Multi-Task Representation Learning

Driving in a dynamic, multi-agent, and complex urban environment is a difficult task requiring a complex decision-making policy. The learning of such a policy requires a state representation that can encode the entire environment. Mid-level representations that encode a vehicle's environment as images have become a popular choice. Still, they are quite high-dimensional, limiting their use in data-hungry approaches such as reinforcement learning. In this article, we propose to learn a low-dimensional and rich latent representation of the environment by leveraging the knowledge of relevant semantic factors. To do this, we train an encoder-decoder deep neural network to predict multiple application-relevant factors such as the trajectories of other agents and the ego car. Furthermore, we propose a hazard signal based on other vehicles' future trajectories and the planned route which is used in conjunction with the learned latent representation as input to a down-stream policy. We demonstrate that using the multi-head encoder-decoder neural network results in a more informative representation than a standard single-head model. In particular, the proposed representation learning and the hazard signal help reinforcement learning to learn faster, with increased performance and less data than baseline methods

Can nurse teachers manage student incivility by guided democracy? A grounded theory study

Method In-depth semi-structured interviews were conducted using theoretical and purposive sampling. Constant comparative analysis was used for data analysis.Results The results include four main categories; (1) deterioration of learning; (2) dominant individual and organisational culture; (3) guided democracy; and (4) movement toward professionalism. Guided democracy is recognised as the main basic psychosocial process for incivility management.Conclusions Incivility management is pursued to help learners develop professional performance. As indicated by the results of the present study, guided democracy is an effective strategy for incivility management in nursing education