Digital Commons Network^™

A Numerical Scheme For Mullins-Sekerka Flow In Three Space Dimensions, Sarah Marie Brown

Theses and Dissertations

The Mullins-Sekerka problem, also called two-sided Hele-Shaw flow, arises in modeling a binary material with two stable concentration phases. A coarsening process occurs, and large particles grow while smaller particles eventually dissolve. Single particles become spherical. This process is described by evolving harmonic functions within the two phases with the moving interface driven by the jump in the normal derivatives of the harmonic functions at the interface. The harmonic functions are continuous across the interface, taking on values equal to the mean curvature of the interface. This dissertation reformulates the three-dimensional problem as one on the two-dimensional interface by using …

Reasoning About Motion: A Case Study, Tiffini Lynn Glaze

Theses and Dissertations

Several dance and industrial design students were given the opportunity to attend a non-traditional mathematics course. The nature of this course prompted student interaction and expected collaboration. My research focuses on one dance student, Sara, who did not consider herself a strong mathematics student, but who understood physical motion very well. This paper explores the evolution of Sara's representations for physical motion in a given task, and discusses her reasoning for keeping or dismissing various parts of her representations during the course of this task. I examine first how Sara learns mathematics with understanding in this task, and second how …

Communities, Place, And Conservation On Mount Kilimanjaro, Marie Bradshaw Durrant

Theses and Dissertations

The Chagga people have lived and worked on Mount Kilimanjaro for more than 250 years. Through traditions and social practices within their communities and families, strong bonds are established between the Chagga and their home on the mountain. Kilimanjaro National Park and Forest Reserve (KINAPA) was established in the 1970s to protect and conserve the mountain, based on a long history of colonialism and western ideals. As KINAPA has attempted to preserve the flora and fauna on the uppermost portion of Mount Kilimanjaro, they have alienated local residents from the land through a conservation approach that relies on "fences and …

Learning To Create: A Collection Of Personal Essays, Naomi Lund Christiansen

Theses and Dissertations

This is a creative thesis that focuses on the infertility experiences of the author. The introduction examines the author's justification for choosing personal essay as a genre and French feminism as the guiding theory in writing the essays. Six personal essays center on the author's attempts to have a child and the discoveries and failures along the way. Throughout literary history, women's bodies have traditionally been viewed from the outside looking in, as objects to be reified and preserved or exploited and used. Using the writing the body critics as a theoretical framework, the essays discuss the comforts and discomforts …

A Hydrothermal After-Ripening Time Model Of Seed Dormancy Loss In Bromus Tectorum, Necia Beck Bair

Theses and Dissertations

After-ripening, the process of seed dormancy loss in dry storage is associated with a decrease in the mean base water potential, one of the parameters of hydrothermal time. The rate of change of the mean base water potential is assumed to be a linear function of temperature above a specific base temperature and as a result can be described by a thermal after-ripening (TAR) time model, an extension of hydrothermal modelling. The thermal requirement for after-ripening is the thermal time necessary for the modelling base water potential of the seed to shift from its original value to its final value. …

Architectures For Symbol Timing Synchronization In Mimo Communications, Kejing Liu

Theses and Dissertations

Maximum likelihood symbol timing estimation for communication over a frequency non-selective MIMO fading channel is developed. The cases of known data (data-aided estimation) and unknown data (non-data-aided estimation) together with known channel and unknown channel are considered. The analysis shows that the log-likelihood functions and their approximations can be interpreted as SISO log-likelihood functions operating on each of the receive antennas. Previously published symbol timing estimators are shown to be special cases of the more general framework presented. Architectures based on both block processing and sequential processing using a discrete-time phase-locked loop are summarized. Performance examples over a MIMO channel …

Through The Eyes Of Shamans: Childhood And The Construction Of Identity In Rosario Castellanos' "Balun-Canan" And Rudolfo Anaya's "Bless Me, Ultima", Tomas Hidalgo Nava

Theses and Dissertations

This study offers a comparative analysis of Rosario Castellanos' Balún-Canán and Rudolfo Anaya's Bless Me, Ultima, novels that provide examples on how children construct their identity in hybrid communities in southeastern Mexico and the U.S. southwest. The protagonists grow and develop in a context where they need to build bridges between their European and Amerindian roots in the middle of external influences that complicate the construction of a new mestizo consciousness. In order to attain that consciousness and free themselves from their divided selves, these children receive the aid of an indigenous mentor who teaches them how to establish a …

Wideband Channel Characterization For Mimo Scenario, Justin T. Holzer

Theses and Dissertations

Because broadband wireless systems benefit from accurate channel characterization, there is growing interest in broadband wireless multiple-input multiple-output (MIMO) channel models. This thesis verifies the suitability of the Saleh Valenzuela with Angle (SVA) model for wideband MIMO communication models. While recent wideband MIMO measurements have been obtained by switching a single transmit/receive pair over all possible antenna pair combinations, a simultaneous probing system is superior because of the time required for the antenna-switching channel measurements. This work provides two different wideband channel estimation algorithms based on simultaneous transmission from and reception on all antennas. Simulated data from an electromagnetic ray …

Consensus Seeking, Formation Keeping, And Trajectory Tracking In Multiple Vehicle Cooperative Control, Wei Ren

Theses and Dissertations

Cooperative control problems for multiple vehicle systems can be categorized as either formation control problems with applications to mobile robots, unmanned air vehicles, autonomous underwater vehicles, satellites, aircraft, spacecraft, and automated highway systems, or non-formation control problems such as task assignment, cooperative transport, cooperative role assignment, air traffic control, cooperative timing, and cooperative search. The cooperative control of multiple vehicle systems poses significant theoretical and practical challenges. For cooperative control strategies to be successful, numerous issues must be addressed. We consider three important and correlated issues: consensus seeking, formation keeping, and trajectory tracking. For consensus seeking, we investigate algorithms and …

Flexible Machine Tool Control For Direct, In-Process Dimensional Part Inspection, Tyler Addison Davis

Theses and Dissertations

For some time now coordinate measuring machines have been an integral part of the shop floor. The goal has been to make coordinate measuring machines (CMMs) into tools that can easily be used by machinists to improve their manufacturing capabilities. The value of a CMM as a quality control tool is undisputed. Now efforts are being made to further reduce the time and cost of measurement by reducing the physical distance between machining and measuring processes. The ability to reduce that distance to zero and measure a part directly on the chip-making machine has been a goal for many years. …

The Effect Of Religiosity And Spirituality On Work Practices And Trust Levels In Managers And Their Subordinates In Food And Nutrition Care Departments, Jennifer S. Oler

Theses and Dissertations

The purpose of this study was to examine the extent to which religiosity and spirituality affected daily work practices and leader/follower trust levels in foodservice and nutrition directors and their subordinates. A similar 72-item survey questionnaire was developed for both the directors and employees, which was completed by 129 directors and 530 employees. Both questionnaires contained questions on demographics, religious influences on work practices, trust characteristics, and three validated measures of religiosity: 1) worship service attendance (1=Religiosity Score), 2) influence of spiritual beliefs on daily life, and 3) frequency of prayer (2 + 3=Spirituality Score). Frequency data was gathered for …

Body Mass Index And Soft Drink Consumption Among Adolescents, Olivia Love Mccord

Theses and Dissertations

Objective: To determine the relationship between body mass index (BMI) and soft drink consumption among adolescents. It is hypothesized that soft drink consumption contributes to overweight and obesity among adolescents.

Background: Research examining the relationship between body mass index and soft drink consumption is inconsistent. Several studies have found a negative association between total sugar intake and BMI; however, others have found a link between sugar-sweetened drinks and obesity. There are no known studies that have controlled for physical activity.

Data and Methods: Data on approximately 225 adolescents were used. Frequency of soft drink consumption, type of milk, and calcium …

Motion Compensation Of Interferometric Synthetic Aperture Radar, David P. Duncan

Theses and Dissertations

Deviations from a nominal, straight-line flight path of a synthetic aperture radar (SAR) lead to inaccurate and defocused radar images. This thesis is an investigation into the improvement of the motion compensation algorithm created for the BYU inteferometric synthetic aperture radar, YINSAR. The existing BYU SAR processing algorithm produces improved radar imagery but does not fully account for variations in attitude (roll, pitch, yaw) and does not function well with large position deviations. Results in this thesis demonstrate that a higher order motion compensation algorithm is not as effective as using a segmented reference track, coupled with the current lower-order …

Grouping Search-Engine Returned Citations For Person-Name Queries, Reema Al-Kamha

Theses and Dissertations

In this thesis we present a technique to group search-engine returned citations for person-name queries, such that the search-engine returned citations in each group belong to the same person. To group the returned citations we use a multi-faceted approach that considers evidence from three facets: (1) attributes, (2) links, and (3) page similarity. For each facet we generate a confidence matrix. Then we construct a final confidence matrix for all facets. Using a threshold, we apply a grouping algorithm on the final confidence matrix. The output is a group of search-engine returned citations, such that the citations in each group …

A Formal Semantic Analysis Of Autistic Language: The Quantification Hypothesis, Michael B. Manookin

Theses and Dissertations

Autism is characterized by language dysfunction ranging from mild and peculiar language usage to a total lack of expressive language function. These language oddities are manifest in the form of phonological, morphological, syntactic, semantic, and pragmatic/behavioral dysfunction. Research suggests that the autistic language deficit is focal—dealing with a specific area of language processing; however, previous research has failed to identify this language enigma. This thesis demonstrates a novel approach to the problem, showing that the autistic language deficit is tied to a particular aspect of language processing—quantification. Quantification is defined and explained in the context of autistic language and behavior.

Psl(2,7)-Extensions With Certain Ramification At Two Primes, Glen E. Simpson

Theses and Dissertations

We conduct a parallel Hunter search in order to find a degree 7 number field K ramified at primes q and p with discriminant d(K)=q^6 p^2 where q=11 and 2

Parameters Estimation Using Some Analytical Solutions Of The Anisotropic Advection-Dispersion Model, Federico Catania, Marco Massabò, Ombretta Paladino

International Congress on Environmental Modelling and Software

In this paper some analytical solutions of the advection-dispersion equation are proposed andadopted to solve a non-linear parameter estimation problem. To test the robustness of the analyticalsolutions if adopted in inverse problems, the anisotropic dispersion coefficients are estimated using sets ofexperimental data simulated by Monte Carlo techniques. Cylindrical geometry is considered since largecolumns are the most common devices adopted to study both dispersion and kinetics mechanisms and, evenif the solutions are expressed in terms of Bessel function expansion and equations solved only for particularinitial and boundary conditions, they give very good results in terms of reliability and precision of ourestimates. …

Relative Importance Of Model And Parameter Uncertainty In Models Used For Prediction Of Persistence And Long-Range Transport Potential Of Chemical Pollutants, K. Fenner, M. J. Macleod, M. Stroebe, A. Beyer, M. Scheringer

International Congress on Environmental Modelling and Software

Overall persistence (POV) and long-range transport potential (LRTP) of chemicals are two indicators used in the context of precautionary chemical assessment. Multimedia fate models are used in research and regulatory contexts to calculate numerical indicators of POV and LRTP. The resulting indicator values exhibit uncertainty due to model uncertainty concerning model design and due to variability and uncertainty in the substance parameters. In this study, we compare the relative magnitude of substance parameter and model uncertainty for a large set of 3175 hypothetical chemicals that evenly cover the chemical parameter space and for eight different multimedia models available for the …

Continuous Simulation In Material Flow Networks, A. Moeller

International Congress on Environmental Modelling and Software

Software systems supporting industrial ecology, corporate material flow analysis and life cycle assessment, are normally used as environmental accounting systems. Using these software systems it is easy to model material and energy flow networks with hundreds or even thousands of processes. Environmental accounting systems are not only utilised to analyse and control existing material and energy flow systems, they are also applied to assess future scenarios in steady-state models. But these systems do not support dynamic modelling. Even though dynamic behaviour is not the main focus of environmental accounting systems, sometimes simulation models are required to estimate material and energy …

Soil Hydraulics Properties Estimation By Using Pedotransfer Functions In A Northeastern Semiarid Zone Catchment, Brazil, Lúcio Flávio Ferreira Moreira, A. M. Righetto, V. M. De A. Medeiros

International Congress on Environmental Modelling and Software

Hydrological modeling of the unsaturated soil zone fluxes allows the transfer processes simulation through the hydrological active soil zone. The pedotransfer functions (FTP) are useful tools in the modeling process. They contain analytical functions derived through statistic optimization process using a large amount of soil information data. This paper aims to analyze the level of reliability of two different pedotransfer functions [Wösten et al. (2001); Hodnett and Tomasella (2000)] by using field measurement of soil properties and experimental infiltration data through a disc infiltrometer in an experimental catchment at northeastern semi arid zone of Brazil. FTP’s used in this study …

Uncertainties In Lca Of Plant-Growth Regulators And Implications On Decision-Making, Georg Geisler, Stefanie Hellweg, Konrad Hungerbühler

International Congress on Environmental Modelling and Software

Uncertainty assessment in LCA enables the evaluation of the significance of results, which is important for providing sound decision-support. In this work, an LCA was performed on two plant-growth regulators considering various sources of uncertainty: In the LCI, uncertainties of imprecise measurements of elementary flows, temporal and spatial variation, and different production processes were assessed. In the characterisation phase, the uncertainties of substance properties and the composition of sum-parameters were considered. These uncertainties were expressed as probability distributions and assessed via stochastic modelling (Monte-Carlo Simulation). For most LCI- and LCIA-data, generic uncertainty ranges were used. Uncertainties due to assumptions on …

Modelling The Dynamics Of Public Attention Towards Environmental Issues, Jens Newig, Julia Hesselmann

International Congress on Environmental Modelling and Software

Public attention, traced over time, often displays seemingly paradox behaviour: Contrary towhat one might expect, public concern is seldom highest when the environmental conditions are the worst.Rather, concern most often rises when conditions have already become better. Furthermore, public attentiondynamics frequently shows self-reinforcing behaviour resulting in distinct cycles, e.g. due to sometrigger event. In this paper, public attention is viewed as a social macro-level phenomenon that is soughtto be explained by the interaction of a multitude of single actors, namely individual citizens, the press, andpoliticians. First, a causal model based on rational choice theory is constructed in order to elucidate …

Collaborative Decision-Making Processes For Maintaining Biodiversity: Two Australian Case Studies, C. Pettit, D. Pullar

International Congress on Environmental Modelling and Software

There have been many models developed by scientists to assist decision-makers in making socio-economic and environmental decisions. It is now recognised that there is a shift in the dominant paradigm to making decisions with stakeholders, rather than making decisions for stakeholders. Our paper investigates two case studies where group model building has been undertaken for maintaining biodiversity in Australia. The first case study focuses on preservation and management of green spaces and biodiversity in metropolitan Melbourne under the umbrella of the Melbourne 2030 planning strategy. A geographical information system is used to collate a number of spatial datasets encompassing a …

Agents, Bayes, And Climatic Risks – A Modular Modelling Approach, Armin Haas, Carlo Jaeger

International Congress on Environmental Modelling and Software

When insurance firms, energy companies, governments, NGOs, and other agents strive to manageclimatic risks, it is by no way clear what the aggregate outcome should and will be. As a framework forinvestigating this subject, we present the LAGOM model family. It is based on modules depicting learningsocial agents. For managing climate risks, our agents use second order probabilities and update them by meansof a Bayesian mechanism while differing in priors and risk aversion. The interactions between these modulesand the aggregate outcomes of their actions are implemented using further modules. The software system isimplemented as a series of parallel processes using …

Site Planning At Tamborine Mountain, Gold Coast, Australia, Christine Lim, Michael Mcaleer, Yu-Chi Wang

International Congress on Environmental Modelling and Software

Tamborine Mountain is a 25 square kilometre plateau located within the urban-rural fringe of the Gold Coast, Queensland, Australia. Renowned for its superb climate, spectacular views, lush farmland and subtropical rainforest, Tamborine Mountain offers a wide variety of nature-based tourism activities such as bushwalking, rainforest appreciation and wine tasting. This phenomenon requires the harmonious development of tourism and the environment. This paper examines site planning at Tamborine Mountain, with a focus on two of its main tourist attractions, namely the Winery and National Parks. A strategic approach is used to evaluate some of the strengths and weaknesses of their existing …

Time Blanking For Gbt Data With Radar Rfi, Weizhen Dong

Theses and Dissertations

The 1215 MHz to 1400 MHz band is important for radio astronomers to observe redshifted extragalactic hydrogen ionic (HI). Observations at these frequencies are complicated by radio frequency interference (RFI) from strong man-made transmissions such as the ARSR-3 Air Surveillance Radar. In this thesis, we characterize some data files recorded at the National Radio Astronomy Observatory (NRAO) at Green Bank, West Virginia, USA, where this RADAR system causes significant data corruption. Using this data, we present a blanking technique to separate RFI from cosmic signal. There are generally two blanking approaches, time window blanking and detected pulse blanking. Compared with …

Blank Pages Of The Holocaust: Gypsies In Yugoslavia During World War Ii, Elizabeta Jevtic

Theses and Dissertations

After a general overview of the persecution of Gypsies (Roma) during World War II, this thesis focuses on the situation of Gypsies on the territory of Serbia and Croatia. The two republics are chosen because of their unique structures during the years 1941 to 1945. Both republics had puppet regimes set up by Germany; however, Croatia was an ally to Germany and strove to mirror the Third Reich in all its policies. The regime's head, Ante Pavelic, was known as one of the most brutal and merciless men on the territory of Yugoslavia, and with him Croatian paramilitary forces committed …

Adaptation, Enactment, And Ingmar Bergman's Magic Flute, Dean W. Duncan

BYU Studies

For all of its manifold musical glories, The Magic Flute was and is a theatrical work, meant for production and performance, and that repeatedly. As such, I will be concentrating on the opera's theatrical and cinematic elements. This article treats Ingmar Bergman's felicitous 1975 film adaptation of opera. Those inclined can find much to complain about in Bergman's cinematic version of Mozart's opera, but I would like to suggest that, with sympathy and openness, this complaining could give way to approval and great gratitude. In this Magic Flute, we have an interpretation worthy of its source, which is saying …

Simulation Of Herbicide Transport In An Alluvial Plain, K. Meiwirth, A. Mermoud

International Congress on Environmental Modelling and Software

Herbicide transport through the vadose zone was studied in the Upper Rhône River Valley (South- West Switzerland). The herbicides atrazine and isoproturon were applied to instrumented field plots and the concentrations reaching the groundwater were measured. The solute transport is closely linked to precipitation. Following the first heavy rainfall after the application, the chemicals are quickly transported through the vadose zone and reach the groundwater in a short time. The transport experiments were simulated with the mechanistic deterministic model HYDRUS-1D. The mobile-immobile water concept was used to account for the rapid transport. In the study area, the shallow groundwater influences …

Optimal Sampling For Parameters Estimation, Federico Catania, Marco Massabò, R. Minciardi, Ombretta Paladino

International Congress on Environmental Modelling and Software

In the problems concerning prediction and modeling, parameters estimation constitutes one of the main uncertain items that must be taken into account. The easiest way to minimize this uncertainty is to collect great amounts of data. The aim of this work is to build a decision model able to choose the optimal position of the sample point used for the parameters estimation, minimizing the parameters uncertainty. The decision model is applied to the estimation of the dispersivity coefficients, longitudinal and transversal, from soil column experiment. The classical design of experiments techniques are based on the optimization of the amount of …