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Articles 2641 - 2670 of 4850

Full-Text Articles in Engineering

Using Integrated Environmental Modeling To Automate A Process-Based Quantitative Microbial Risk Assessment, Gene Whelan, Keewook Kim, Rajbir Parmar, Kurt Wolfe, Mike Galvin, Paul Duda, Mark Gray, Marirosa Molina, Richard Zepp, Yakov Pachepsky, John Ravenscroft, Lourdes Prieto, Brenda Kitchens Jun 2014

Using Integrated Environmental Modeling To Automate A Process-Based Quantitative Microbial Risk Assessment, Gene Whelan, Keewook Kim, Rajbir Parmar, Kurt Wolfe, Mike Galvin, Paul Duda, Mark Gray, Marirosa Molina, Richard Zepp, Yakov Pachepsky, John Ravenscroft, Lourdes Prieto, Brenda Kitchens

International Congress on Environmental Modelling and Software

Integrated Environmental Modeling (IEM) organizes multidisciplinary knowledge that explains and predicts environmental-system response to stressors. A Quantitative Microbial Risk Assessment (QMRA) is an approach integrating a range of disparate data (fate/transport, exposure, and human health effects relationships) to characterize potential health impacts/risks from exposure to pathogenic microorganisms. We demonstrate loosely connected IEM legacy technologies (SDMProjectBuilder, Microbial Source Module, HSPF, and BASINS) to support watershed-scale microbial source-to-receptor modeling, focusing on animal-impacted catchments. The coupled models automate manual steps in standard watershed assessments to expedite the process, minimize resources, increase ease of use, and introduce more science-based processes to the analysis. SDMProjectBuilder …

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Toward Integrated Environmental Modeling Using Research Data Infastructures, Jeffery S. Horsburgh Jun 2014

Toward Integrated Environmental Modeling Using Research Data Infastructures, Jeffery S. Horsburgh

International Congress on Environmental Modelling and Software

Anticipated changes to climate, human population, land use, and urban form will alter the hydrology and availability of water within the water systems on which the world's population relies. Managing water resources, as well as maintaining associated capacity to provide ecosystem services (e.g., regulating flooding, maintaining instream flow during dry periods, cycling nutrients, and maintaining water quality) will require better information characterizing both the natural hydrologic system and human mediated hydrologic systems. The next generation of integrated environmental models will seek to provide this information but requires better access to data at the spatial and temporal scales relevant to decision …

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The Csdms Standard Names: Cross-Domain Naming Conventions For Describing Process Models, Data Sets And Their Associated Variables, Scott D. Peckham Jun 2014

The Csdms Standard Names: Cross-Domain Naming Conventions For Describing Process Models, Data Sets And Their Associated Variables, Scott D. Peckham

International Congress on Environmental Modelling and Software

The CSDMS (Community Surface Dynamics Modeling System) modeling framework provides mechanisms that allow models and data sets from different contributors to be automatically coupled in a plug-and-play manner to create composite models. In developing this capability, a key challenge has been that of automatic semantic mediation, or name matching, because each model or data set (here called a resource) uses its own set of terms for input and output variable names. These names are often domain-specific or abbreviated. In order for the CSDMS framework to determine whether one model’s output variable is appropriate to be used as another model’s input …

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Sensitivity And Uncertainty Analysis Of A Plant-Wide Model For Carbon And Energy Footprint Of Wastewater Treatment Plants, Giorgio Mannina, Alida Cosenza, Riccardo Gori, Reza Sobhani, Manel Garrido, Diego Rosso Jun 2014

Sensitivity And Uncertainty Analysis Of A Plant-Wide Model For Carbon And Energy Footprint Of Wastewater Treatment Plants, Giorgio Mannina, Alida Cosenza, Riccardo Gori, Reza Sobhani, Manel Garrido, Diego Rosso

International Congress on Environmental Modelling and Software

This paper presents the sensitivity and uncertainty analysis of a mathematical model for Greenhouse gas (GHG) and energy consumption assessment from wastewater treatment plants (WWTPs). The model is able to simultaneously describe the main biological and physical-chemical processes in WWTP. Specifically, the mathematical model includes the main processes of the water and sludge lines influencing the methane (CH4), nitrous oxide (N2O), and carbon dioxide (CO2) emissions. Further, the process energy demand and the energy recovery are also taken into account. The main objective of this paper is to analyze the key factors and sources …

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App2adapt: Using Tablet Technology To Elicit Conditional Probabilities For Bayesian Belief Network Modelling, Russell Richards, Oz Sahin, Marcello Sano, Jan-Olaf Meynecke, Rachel Tiller Jun 2014

App2adapt: Using Tablet Technology To Elicit Conditional Probabilities For Bayesian Belief Network Modelling, Russell Richards, Oz Sahin, Marcello Sano, Jan-Olaf Meynecke, Rachel Tiller

International Congress on Environmental Modelling and Software

The aim of this study is to use touch-screen computer tablet technology (e.g. iPAD) and its interactive flight console capabilities (e.g. touch screen 'sliders') as an improved method to stakeholder­ driven climate change adaptation research. Climate change vulnerability and adaptation have strong human dimensions meaning that the experiences of stakeholders often plays an important role when assessing adaptation options and/or the determinants of adaptive capacity. Methods such as Bayesian belief networks {BBNs) can draw upon the extensive knowledge and beliefs of stakeholders in a straightforward manner yet are underpinned by a robust mathematical framework (i.e. Bayes theory). This is critically …

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Metadata For Describing Water Models, Mohamed M. Morsy, Jonathan L. Goodall, Christina Bandaragoda, Anthony M. Castronova, Jane Greenberg Jun 2014

Metadata For Describing Water Models, Mohamed M. Morsy, Jonathan L. Goodall, Christina Bandaragoda, Anthony M. Castronova, Jane Greenberg

International Congress on Environmental Modelling and Software

Computer models are widely used in hydrology and water resources management. A large variety of models exist, each tailored to address specific challenges related to hydrologic science and water resources management. When scientists and engineers apply one of these models to address a specific question, they must devote significant effort to set up, calibrate, and evaluate that model instance built for some place and time. In many cases, there is a benefit to sharing these computer models and associated datasets with the broader scientific community. Core to model reuse in any context is metadata describing the model. A standardized metadata …

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Engaging Australian Surf Lifesaving In Coastal Hazard And Climate Change Adaptation With Stakeholder Driven Modelling, Marcello Sono, Russell G. Richards, Oz Sahin, Shauna Sherker, Rodger Tomlinson Jun 2014

Engaging Australian Surf Lifesaving In Coastal Hazard And Climate Change Adaptation With Stakeholder Driven Modelling, Marcello Sono, Russell G. Richards, Oz Sahin, Shauna Sherker, Rodger Tomlinson

International Congress on Environmental Modelling and Software

Australia's beaches, an iconic playground and social hub for coastal communities, are threatened by coastal hazards and by the impacts of climate change. In particular, Surf Life Saving Australia (SLSA) has assets, facilities and personnel exposed to coastal hazards and climate change, including numerous surf life saving clubs (SLSCs), which can impact its capacity of providing beach and water safety for Australian beaches. This research employed a range of methods to identify climate change adaptation options and to identify mechanisms to enhance adaptive capacity, combining a range of system-oriented, stakeholder-based techniques, including system thinking conceptual modelling, structural analysis, system dynamics …

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Addressing The Water-Energy-Climate Nexus Conundrum: A Systems Approach, Oz Sahin, Rodney A. Stewart, Russell G. Richards Jun 2014

Addressing The Water-Energy-Climate Nexus Conundrum: A Systems Approach, Oz Sahin, Rodney A. Stewart, Russell G. Richards

International Congress on Environmental Modelling and Software

Australia has the highest per capita surface water storage capacity of any country in the world. However, this storage capacity is at the mercy of Australia's rainfall, which is the most variable of any continental region. Recent drought shaved more than 1% off the nation's economy and saw unprecedented widespread water scarcity. In South-East Queensland (SEQ), six consecutive annual drops in storage level forced the introduction of water restrictions, limiting over 2 million citizens to less than 30% of pre-drought per capita usage. Moving forward, forecasts of high population growth and climate change will simultaneously increase water demand and significantly …

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Linking Water Resource Network Models To An Open Data Management Platform, Phillipp Meier, Stephen Knox, Julien Harou Jun 2014

Linking Water Resource Network Models To An Open Data Management Platform, Phillipp Meier, Stephen Knox, Julien Harou

International Congress on Environmental Modelling and Software

The development of models for complex water resources systems frequently involves cus- tomising model formulations to fit unique institutional or physical problems. Linking existing model components is part of this process. As an alternative to pre-packaged models or building models based on components that comply to the same standard interface we present a model platform where network resource models (water, energy, transport, etc.) are linked to a data manager in a generic way. A modular architecture is achieved using a server for data storage. Clients connecting to the server, called Apps, provide import and export functions from and to various …

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Multiscale Spatial Sensitivity Analysis For Agent-Based Modelling Of Coupled Landscape And Aquatic Systems, Arika Ligmann-Zielinska, Wei Liu, Daniel B. Kramer, Kendra Spence Cheruvelil, Patricia A. Soranno, Piotr Jankowski, Seda Salap Jun 2014

Multiscale Spatial Sensitivity Analysis For Agent-Based Modelling Of Coupled Landscape And Aquatic Systems, Arika Ligmann-Zielinska, Wei Liu, Daniel B. Kramer, Kendra Spence Cheruvelil, Patricia A. Soranno, Piotr Jankowski, Seda Salap

International Congress on Environmental Modelling and Software

Models of coupled landscape and aquatic systems (CLAS) are prone to input uncertainties that vary over space. To address this challenge, we employ a comprehensive model evaluation that: [1] quantifies the variability of model results (uncertainty analysis), and [2] decomposes this variability based on the relative contribution of inputs to identify major drivers in the model (sensitivity analysis). Our study simulates how agricultural land conversion from active to fallow lands reduces nutrient loading to lakes. We employ an agent-based model of farmer decision making coupled with a spatially-explicit biophysical lake model. A number of model inputs are uncertain including: variables …

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Defining The Spatiotemporal Surveillance Space For Alien Species' Invasions Using Approximate Bayesian Computation, Grant Hamilton, Rune Rasmussen, Jana Mullerova, Jan Pergl, Petr Pysek Jun 2014

Defining The Spatiotemporal Surveillance Space For Alien Species' Invasions Using Approximate Bayesian Computation, Grant Hamilton, Rune Rasmussen, Jana Mullerova, Jan Pergl, Petr Pysek

International Congress on Environmental Modelling and Software

The spatiotemporal dynamics of an alien species invasion across a real landscape are typically complex. While surveillance is an essential part of a management response, planning surveillance in space and time present a difficult challenge due to this complexity. We show here a method for determining the highest probability sites for occupancy across a landscape at an arbitrary point in the future, based on occupancy data from a single slice in time. We apply to the method to the invasion of Giant Hogweed, a serious weed in the Czech republic and throughout Europe.

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The Effect Of Recovery On Modeling Inactivation Of Bacillus Spores On Hvac Filters, Bharathi Murali, Jade Mitchell Jun 2014

The Effect Of Recovery On Modeling Inactivation Of Bacillus Spores On Hvac Filters, Bharathi Murali, Jade Mitchell

International Congress on Environmental Modelling and Software

The ability of microorganisms to persist on fomite surfaces is an important component in modeling their spread in physical environment. For example, Bacillus anthracis (Ba) spores have been found to be extremely resistant to inactivation, environmental stresses, and stable over decades. Modeling the inactivation of spores could form an integral element for estimating the exposure and the subsequent health risks posed by them. However, there is a knowledge gap in the quantification of recovery of Bacillus spores on porous surfaces, which may have a significant effect on the quantification of their persistence in the environment. Our work investigates the recovery …

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A K-Means Clustering Approach To Assess Wheat Yield Prediction Uncertainty With A Hydrus-1d Coupled Crop Model, Derek Groenendyk, Kelly Thorp, Ty Ferré, Wade Crow, Doug Hunsaker Jun 2014

A K-Means Clustering Approach To Assess Wheat Yield Prediction Uncertainty With A Hydrus-1d Coupled Crop Model, Derek Groenendyk, Kelly Thorp, Ty Ferré, Wade Crow, Doug Hunsaker

International Congress on Environmental Modelling and Software

Soil moisture, especially under drought conditions, is a factor that is known to impact crop yield predictions. Crop growth models used to make these predictions rely on soil texture estimates, which influence simulated soil moisture and ultimately crop growth. The purpose of this research was to implement a k-means clustering approach to address the uncertainty of the soil texture estimates. By grouping similar soil textures based on their simulated responses, clustering reveals how soil texture uncertainty may impact yield estimates. Wheat growth simulations were conducted using a HYDRUS 1D and coupled crop model for soils defined on the USDA soil …

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Gis-Based Environmental Modeling With Tangible Interaction And Dynamic Visualization, Anna Petrasova, Brendan Harmon, Vaclav Petras, Helena Mitasova Jun 2014

Gis-Based Environmental Modeling With Tangible Interaction And Dynamic Visualization, Anna Petrasova, Brendan Harmon, Vaclav Petras, Helena Mitasova

International Congress on Environmental Modelling and Software

We present a new, affordable version of TanGeoMS, a tangible geospatial modeling and visualization system designed for collaboratively exploring how terrain change impacts landscape pro­ cesses. It couples a physical, three-dimensional model of a landscape with geospatial modeling and analysis through a cycle of scanning and projection. Multiple users can modify the physical model by hand while it is being scanned; by sculpting the model they generate input for modeling of geophysical processes. The modeling results are then visualized by projecting images or animations back on the physical model. This feedback loop is an intuitive way to evaluate the impacts …

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Calibration Of Simulation Platforms Including Highly Interweaved Processes: The Maelia Multi-Agent Platform, Romain Lardy, Pierre Mazzega, Christophe Sibertin-Blanc, Yves Auda, José-Miguel Sanchez-Perez, Sabine Sauvage, Olivier Therond Jun 2014

Calibration Of Simulation Platforms Including Highly Interweaved Processes: The Maelia Multi-Agent Platform, Romain Lardy, Pierre Mazzega, Christophe Sibertin-Blanc, Yves Auda, José-Miguel Sanchez-Perez, Sabine Sauvage, Olivier Therond

International Congress on Environmental Modelling and Software

The MAELIA project develops an agent-based modeling and simulation platform to study the environmental, economic and social impacts of various regulations regarding water use and water management in combination with climate change. An integrated modelling approach has been used to model the investigated social-ecological system. MAELIA combines spatiotemporal models of ecologic (e.g. water flow and plant growth) and human decision-making processes (e.g. cropping plan), socio-economic dynamics (e.g. land cover changes). Due to the diversity and the interweaving of the processes considered, the calibration and evaluation of such a multi-agent platform is a scientific challenge. Indeed, many parameters can reveal to …

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An Environmental Modeling Language For Agents And Fields, Kor De Jong, Merijn De Bakker, Derek Karssenberg Jun 2014

An Environmental Modeling Language For Agents And Fields, Kor De Jong, Merijn De Bakker, Derek Karssenberg

International Congress on Environmental Modelling and Software

Environmental modeling involves manipulating environmental attributes represented in soft­ware by agents, fields or both, but most modeling environments are designed to be especially useful for either agent-based or field-based modeling. Agent-based and field-based modeling environments have different properties with respect to their ease of use and how well both agents and fields can be represented and manipulated. Most agent-based modeling environments require the modeler to use a general purpose object oriented programming language like Java to express models, while field-based modeling environments often implement a high level, domain specific imperative language based on map algebra, or extent a general purpose …

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An Integrated Approach For Including Social Capacities, And Economic Valuation In Risk Assessment Of Water Related Hazards In Uncertain Scenarios, Carlo Giupponi, Vahid Mojtahed, Animesh K. Gain, Stefano Balbi, Claudio Biscaro Jun 2014

An Integrated Approach For Including Social Capacities, And Economic Valuation In Risk Assessment Of Water Related Hazards In Uncertain Scenarios, Carlo Giupponi, Vahid Mojtahed, Animesh K. Gain, Stefano Balbi, Claudio Biscaro

International Congress on Environmental Modelling and Software

We propose a conceptual framework, KR-FWK (i.e. KULTURisk Framework from the name of the European project within which it originated) and its implementation methods SERRA (Socio-Economic Regional Risk Assessment) for integrated (physical and economical) risk assessment, and economic valuation of risk prevention benefits on multiple receptors. The KR-FWK and the SERRA approach are characterised by: (i) integration of physical-environmental dimensions and the socio-economic ones in risk assessment; (ii) consideration of the role of social capacities (adaptive and coping capacity) in reducing risk and related costs, (iii) quantitative (even monetary) assessment of risks and of the benefits of risk reduction measures, …

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Agile Workflows For Climate Impact Risk Assessment Based On The Ci:Grasp Platform And The Jabc Modeling Framework, Samih Al-Areqi, Anna-Lena Lamprecht, Tiziana Margaria, Steffen Kriewald, Dominik Reusser, Markus Wrobel Jun 2014

Agile Workflows For Climate Impact Risk Assessment Based On The Ci:Grasp Platform And The Jabc Modeling Framework, Samih Al-Areqi, Anna-Lena Lamprecht, Tiziana Margaria, Steffen Kriewald, Dominik Reusser, Markus Wrobel

International Congress on Environmental Modelling and Software

Analyzing and assessing potential impacts of climate change are critical and challenging tasks that require the processing of large and heterogeneous datasets. These analyses are particularly demanding because of the multi-scale and multi-objective nature of environmental modeling for climate change impact assessment. The Climate Impacts: Global and Regional Adaptation Support Platform (ci:grasp) is a web-based climate information service for exploring climate change related information in its geographical context. In this paper, we show how the agile workflow development style supported by the jABC process modeling and execution framework permits us to leverage the processes implemented in the ci:grasp platform to …

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The Data Processing Inequality And Environmental Model Prediction, Steven V. Weijs Jun 2014

The Data Processing Inequality And Environmental Model Prediction, Steven V. Weijs

International Congress on Environmental Modelling and Software

Prediction in environmental systems, such as hydrological streamflow prediction, is a challenging task. Although on a small scale, many of the physical processes are well described, accurate predictions of macroscopical (e.g. catchment scale) behavior with a bottom-up mechanistic approach often remains elusive. On the other hand, conceptual or purely statistical models fitted to data often perform surprisingly well for prediction. The data processing inequality, from the field of information theory, says that processing data with statistical procedures can only decrease, and not increase the information content of the data. This seems to contradict the intuition that our knowledge of physical …

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Managing Agricultural Landscapes For Favouring Ecosystem Services Provided By Biodiversity: A Spatially Explicit Model Of Crop Rotations In The Gama Simulation Platform, Hugo Thierry, Aude Vialatte, Jean-Philippe Choisis, Benoit Gaudou, Claude Monteil Jun 2014

Managing Agricultural Landscapes For Favouring Ecosystem Services Provided By Biodiversity: A Spatially Explicit Model Of Crop Rotations In The Gama Simulation Platform, Hugo Thierry, Aude Vialatte, Jean-Philippe Choisis, Benoit Gaudou, Claude Monteil

International Congress on Environmental Modelling and Software

The need to reduce the use of pesticides in agricultural ecosystems requires studying and developing new pest regulation methods. Individual-based models are useful to better understand how dynamics of insects interact with agricultural landscapes and to study the potential effects of alternative regulation methods, taking into account the spatial and temporal stochasticity of agricultural ecosystems caused by human management. Crop rotations and crop phenology have an important impact on the life cycles of populations of insects. We developed an individual-based model simulating the dynamics of an agricultural landscape from GIS data. The spatiotemporal stochasticity is simulated using typical landcover rotations …

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Comparison Of One-Dimensional Turbulence And Direct Numerical Simulations Of Soot Formation And Transport In A Nonpremixed Ethylene Jet Flame, David O. Lignell, Garrison C. Fredline, Adam D. Lewis Jun 2014

Comparison Of One-Dimensional Turbulence And Direct Numerical Simulations Of Soot Formation And Transport In A Nonpremixed Ethylene Jet Flame, David O. Lignell, Garrison C. Fredline, Adam D. Lewis

Faculty Publications

Accurate models of soot formation in turbulent flames are important for correctly predicting and simulating flames and fires. Modeling soot formation and transport is challenging due to the complex chemical formation processes, and differential diffusion of soot relative to a flame. Direct numerical simulations (DNS) have highlighted the importance of such transport on soot concentrations, however DNS is computationally expensive. The one-dimensional turbulence (ODT) model is able resolve a full range of length and timescales and solves the evolution of diffusive and reactive scalars in the natural physical coordinate. We present results of soot formation in ODT and compare the …

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Effect Of Video Camera-Based Remote Roadway Condition Monitoring On Snow Removal-Related Maintenance Operations, Seishi Yamagata Jun 2014

Effect Of Video Camera-Based Remote Roadway Condition Monitoring On Snow Removal-Related Maintenance Operations, Seishi Yamagata

Theses and Dissertations

Remote monitoring through the use of cameras is widely utilized for traffic operation, but has not been utilized widely for roadway maintenance operations. The Utah Department of Transportation (UDOT) has implemented a new remote monitoring system, referred to as a Cloud-enabled Remote Video Streaming (CRVS) camera system for snow removal-related maintenance operations in the winter. The purpose of this study was to evaluate the effectiveness of the use of the CRVS camera system in snow removal-related maintenance operations. This study was conducted in two parts: opinion surveys of maintenance station supervisors and an analysis on snow removal-related maintenance costs. The …

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Target Motion Estimation Techniques For Single-Channel Sar, Mark T. Crockett Jun 2014

Target Motion Estimation Techniques For Single-Channel Sar, Mark T. Crockett

Theses and Dissertations

Synthetic aperture radar (SAR) systems are versatile, high-resolution radar imagers useful for providing detailed intelligence, surveillance, and reconnaissance, especially when atmospheric conditions are non-ideal for optical imagers. However, moving targets in SAR images are smeared. Along-track interferometry is a commonly-used method for extracting the motion parameters of moving targets but requires a dual-aperture SAR system, which may be power- size- or cost-prohibitive. This thesis presents a method of estimating target motion parameters in single-channel SAR data given geometric target motion constraints. I test this method on both simulated and actual SAR data. This estimation method includes an initial estimate, computation …

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Evaluation Of Passive Force Behavior For Bridge Abutments Using Large-Scale Tests With Various Backfill Geometries, Jaycee Cornwall Smith Jun 2014

Evaluation Of Passive Force Behavior For Bridge Abutments Using Large-Scale Tests With Various Backfill Geometries, Jaycee Cornwall Smith

Theses and Dissertations

Bridge abutments are designed to withstand lateral pressures from thermal expansion and seismic forces. Current design curves have been seen to dangerously over- and under-estimate the peak passive resistance and corresponding deflection of abutment backfills. Similar studies on passive pressure have shown that passive resistance changes with different types of constructed backfills. The effects of changing the length to width ratio, or including MSE wingwalls determine passive force-deflection relationships. The purpose of this study is to determine the effects of the wall heights and of the MSE support on passive pressure and backfill failure, and to compare the field results …

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Characterization And Optimization Of Thermal Protective Fabrics Designed To Protect Against Splash Hazards, Jeremy Osguthorpe Jun 2014

Characterization And Optimization Of Thermal Protective Fabrics Designed To Protect Against Splash Hazards, Jeremy Osguthorpe

Theses and Dissertations

Thermal textiles used in Personal Protective Equipment (PPE) are used to protect individuals from the hazards of thermal energy. An analytical model of the diffusion of thermal energy within the fabric was developed to simulate the transfer of thermal energy due to a hot liquid splash. Based on the model results, it was determined that that the use of an orthotropic material in which the thermal conductivities in the radial and axial directions are different can be used to decrease the amount of heat transferred through the fabric and thereby increase amount of protection in PPE. An orthotropic material particularly …

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Investigating Virtual Globes For A Prototype Community Archive Of 3d Subsurface Data, Derek C. Whitman Jun 2014

Investigating Virtual Globes For A Prototype Community Archive Of 3d Subsurface Data, Derek C. Whitman

Theses and Dissertations

Geoscience data sharing and processing is very advanced in terms of surface data. Subsurface data sharing has not received the attention that surface data sharing has received and so there are fewer applications or software packages which focus on it. This research is funded by the NSF EarthCube GEO Domain program in an effort to develop a continental-scale repository of 3D subsurface data to facilitate the sharing of complex 3D data and to enable the development of geoprocessing tools and workflows that operate on that data. The work in this thesis is a small part of the EarthCube project with …

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Friction Bit Joining Of Dissimilar Combinations Of Advanced High-Strength Steel And Aluminum Alloys, Lile P. Squires Jun 2014

Friction Bit Joining Of Dissimilar Combinations Of Advanced High-Strength Steel And Aluminum Alloys, Lile P. Squires

Theses and Dissertations

Friction bit joining (FBJ) is a new method that enables lightweight metal to be joined to advanced high-strength steels. Weight reduction through the use of advanced high-strength materials is necessary in the automotive industry, as well as other markets, where weight savings are increasingly emphasized in pursuit of fuel efficiency. The purpose of this research is twofold: (1) to understand the influence that process parameters such as bit design, material type and machine commands have on the consistency and strength of friction bit joints in dissimilar metal alloys; and (2) to pioneer machine and bit configurations that would aid commercial, …

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Current Bim Practices Of Commercial Mep Contractors, Bryan John Kent Jun 2014

Current Bim Practices Of Commercial Mep Contractors, Bryan John Kent

Theses and Dissertations

Building Information Modeling (BIM) use in the contracting industry has grown significantly in recent years. With this change in the construction industry, consensus has not been reached as to what BIM is, who is using it and what they are using it for. The purpose of this research was to determine current BIM practices of US-based commercial MEP contractors. Executive, middle management, and field personnel were interviewed to determine the current BIM practices in their companies. The majority of companies interviewed were using BIM and most were using it on a significant portion of their projects. The majority of MEP …

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Microstructural Factors Of Strain Delocalization In Model Metallic Glass Matrix Composites, Thomas James Hardin Jun 2014

Microstructural Factors Of Strain Delocalization In Model Metallic Glass Matrix Composites, Thomas James Hardin

Theses and Dissertations

Metallic glass matrix composites have enormous potential stemming from the interplay between crystalline and amorphous phases. This work models such a composite using shear transformation zone dynamics (a modified kinetic Monte Carlo method) for the amorphous phase, and a local Taylor dislocation model for the crystalline phase. An N-factorial experiment using the model is presented examining the effects of crystalline volume fraction, microstructure length scale, and yield stress of the crystalline phase. Each replicate is analyzed for maximum stress, maximum strain, strain energy dissipation, strain localization, and strain partitioning between phases. Regression analysis is used to identify statistically-significant trends in …

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Analysis Of Long-Term Utah Temperature Trends Using Hilbert-Haung Transforms, Brent H. Hargis Jun 2014

Analysis Of Long-Term Utah Temperature Trends Using Hilbert-Haung Transforms, Brent H. Hargis

Theses and Dissertations

We analyzed long-term temperature trends in Utah using a relatively new signal processing method called Empirical Mode Decomposition (EMD). We evaluated the available weather records in Utah and selected 52 stations, which had records longer than 60 years, for analysis. We analyzed daily temperature data, both minimum and maximums, using the EMD method that decomposes non-stationary data (data with a trend) into periodic components and the underlying trend. Most decomposition algorithms require stationary data (no trend) with constant periods and temperature data do not meet these constraints. In addition to identifying the long-term trend, we also identified other periodic processes …

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