Digital Commons Network^™

Insights Into Twinning In Mg Az31: A Combined Ebsd And Machine Learning Study, David T. Fullwood, Andrew Orme, Isaac Chelladurai, Travis Michael Rampton, Ali Khosravani, Michael Miles, Raj K. Mishra

Faculty Publications

To explore the driving forces behind deformation twinning in Mg AZ31, a machine learning framework is utilized to mine data obtained from electron backscatter diffraction (EBSD) scans in order to extract correlations in physical characteristics that cause twinning. The results are intended to inform physics-based models of twin nucleation and growth. A decision tree learning environment is selected to capture the relationships between microstructure and twin formation; this type of model effectively highlights the more influential characteristics of the local microstructure. Trees are assembled to analyze both twin nucleation in a given grain, and twin propagation across grain boundaries. Each …

Sensitivity Analysis In Support To Drinking Water Production Plants Optimization, Florin Capitanescu, Antonino Marvuglia, Enrico Benetto, Aras Ahmadi, Ligia Tiruta-Barna

International Congress on Environmental Modelling and Software

In the frameworks of environmental management and computational sustainability, this paper aims at improving, in a cost-effective manner, the sustainability of existing drinking water production plants (DWPPs) via multi-objective constrained optimization (MOO). Specifically, the paper explores the ability of global sensitivity analysis (SA) methods to support MOO of DWPPs by means of a quick identification of a subset of the most sensitive decision variables from a large set, which leads to better quality solutions under limited time budget. To this end, the paper conducts a comparative analysis for this MOO problem of two major SA methods, namely Morris and Sobol’, …

Blueprint Of A System Dynamics Model For Flanders, Jean-Luc De Kok, Peter Viaene, Stijn Vranckx, Karolien Vermeiren, Guy Engelen, Inge Mayeres, Leo De Nocker, Pieter Valkering, Wouter Wetzels, Marleen Van Steertegem, Bert De Vries

International Congress on Environmental Modelling and Software

The development of energy prices, immigration, and other exogenous factors which are beyond control of the authorities add to the uncertainties in long-term environmental planning. Prospective studies such as the Nature Outlook and Environment Outlook are carried out to assess the existing status of nature and the environment in Flanders, to support the mid- and long-term planning, and to ensure that the environmental targets set by the EU are met. The supporting analyses are based on modelling and data for a wide range of social-economic sectors and thematic domains, including demography, economics, energy, mobility, land-use change, environment, agriculture and food …

Optimist: A Python Library For Water System Optimal Operation And Analysis Using Sddp, Luciano Raso, David Dorchies, Jan Kwakkel, Pierre Olivier Malaterre

International Congress on Environmental Modelling and Software

Stochastic Dual Dynamic Programming (SDDP) is valuable tool in water management, employed for operational water management (i.e. suggesting effective release rules), and cost-benefit analysis evaluations. SDDP solves a multistage stochastic programming problem when uncertainty is a Markov process, and the system model is convex. SDDP can handle complex interconnected problem. Despite its potential, SDDP use is limited to few specialists.

We present Optimist, a python library for setting up an SDDP problem from components, i.e. elements and objectives, and their relationships. Elements presently developed are: streamflow input, reservoir, release, and river-reach. Objectives can be linear, used for energy …

Designing Mixed Fruit-Vegetable Cropping Systems By Integer Quadratic Programming, Sara Maqrot, Simon De Givry, Gauthier Quesnel, Marc Tchamitchian

International Congress on Environmental Modelling and Software

Mixed fruit-vegetable cropping systems (MFVCS) are a promising way of ensuring environmentally sustainable agricultural production systems in response to the challenge of being able to fulfill local market requirements. Indeed, they combine productions and they also make a better use of biodiversity. These agroforestry systems are based on a complex set of interactions modifying the utilization of light, water and nutrients. Thus, designing such a system must optimize the use of these resources, by maximizing positive interactions (facilitation) and minimizing negative ones (competition). To attain these objectives, the system's design has to include the spatial and temporal dimensions of these …

Agent-Based Modeling Automated: Data-Driven Generation Of Innovation Diffusion Models, Thorben Jensen, Émile J.L. Chappin

International Congress on Environmental Modelling and Software

Simulation modeling is useful to gain insights into driving mechanisms of diffusion of innovations. This study aims to introduce automation to make identification of such mechanisms with agent-based simulation modeling less costly in time and labor. We present a novel automation procedure in which the generation of diffusion models is automated. It comprises three phases: (1) preprocessing of empirical data on the diffusion of a specific innovation, taken out be the user; (2) automated inverse modeling of decision models from a decision model library for their capability of explaining these data; (3) policy simulation automatically assesses user-chosen policy interventions in …

Explicit Cost Accounting For Adaptation, Mitigation And Ecosystem Service Provision In Agriculture, Franz Sinabell, Karin Heinschink, Christoph Tribl

International Congress on Environmental Modelling and Software

Farmers, policy makers and scientists are well aware of this problem: obtaining sound cost information for climate change adaptation and mitigation measures in agriculture or ecosystem service provision by agriculture is burdensome. In most cases, data sets are developed for a specific region with a given set of management variants for a baseline period. Adapting such information to another region or adjusting costs to expected future price scenarios requires additional efforts and frequently done an ad-hoc and case by case. A new tool is presented that can be used to identify and analyze the entangled effects of future climate and …

Integrated Assessment Of Novel Two-Season Production Systems In Mato Grosso, Brazil, Marcelo Moraes, Affonso Libera, Evgeny Latynskiy, Anna Hampf, José Maria Silveira, Thomas Berger

International Congress on Environmental Modelling and Software

One of the most significant advantages of growing crops in Mato Grosso (in mid-western Brazil) is that farmers can grow two crops (in some specific cases even three) in the same season. From an economic point of view, on the one hand, this provides a strong comparative advantage. On the other hand, this increases the number of decision variables that a decision making agent has to take into account. The agricultural production planning is complex and dynamic and it needs to consider crop rotation/succession in accordance with annual variability of climatic conditions. We developed a region-specific bio-economic micro-simulation model in …

Integrating Scientific Knowledge, Data And Stakeholder Perceptions For Decision Support, Jean-Luc De Kok, Peter Viaene, Karolien Vermeiren, Maarten Van Der Meulen, Rachel Tiller, Murat Ardelan, Jennifer Bailey, Robert Thorpe, Jonathan Beecham, Sonja Van Leeuwen, Frede Thingstad, Tatiana Margo Tsagaraki, Russell Richards, Can Bizsel, Hugo Salgado

International Congress on Environmental Modelling and Software

the marine food web is considered to be a factor of key importance for the global carbon balance. The concept of the ‘Biological Pump’ refers to the mechanism by which CO2 fixed by photosynthesis is transferred to the deep ocean through biologically-driven processes, resulting in sequestration of carbon for a period of decades or longer. Stressors affecting the efficiency of the biological pump include water column stability, sea temperature, acidity, excessive nutrients inputs, overfishing, pollution and other anthropogenic changes. The aim of the EU-FP7 project OCEAN- CERTAIN is to reduce the uncertainties in our understanding of the impacts of these …

Agent-Based Modelling: What Matters Is Action, Franҫois Guerrin, Zoubida Afoutni, Rémy Courdier

International Congress on Environmental Modelling and Software

Computer-aided management tools or models of production systems in the manufacturing or agricultural domains generally rely implicitly on the theory of planned action. Every action is assumed to be part of an anticipated sequence leading from a current state to a predetermined goal. The main limits of this classical view are due to the difficulty to deal with unexpected changes and disturbances. To overcome these limits, we developed an agent model based on the theory of situated action. Whereas the classical approach puts the emphasis on actor’s decision (action being assumed to straightforwardly follow), situated action is viewed as a …

Mathematical Modelling Of Sustainable Fisheries Management In Morocco, H. Essekhyr, K. Elkalay, K. Khalil

International Congress on Environmental Modelling and Software

Moroccan Atlantic coast is considered as one of the richest fishing areas in the world that support a rich assortment of aquatic biological diversity. In the past decade, the fisheries sector has achieved considerable growth. However, the sector suffers from many serious problems that need to be resolved to ensure their sustainable development. Such problems include over-fishing in the coastal, degradation of the marine environment and coastal resources. In this study, a mass-balance Ecopath Model of the Moroccan Atlantic coast is constructed, for improving fisheries management and attaining sustainable development of coastal fisheries in this ecosystem. The results indicate that …

Autoflow© - A Novel Application For Water Resource Management And Climate Change Response Using Smart Technology, Khoi Anh Nguyen, Oz Sahin, Rodney Anthony Stewart, Hong Zhang

International Congress on Environmental Modelling and Software

Urban areas are increasingly at risk from climate change, with negative impacts predicted for human health, the economy and ecosystems. These risks require responses from cities to improve their resilience. Several analysis platforms have been developed worldwide to help effectively control and response to these impacts from different angles, including water resources management, energy production and consumption management, air pollution control, or other natural resources management. To contribute to this goal, Griffith University in Australia has developed Autoflow^©, a smart application for water demand analysis and carbon emission monitoring and prediction. Various advanced mathematical models have been …

An Agent-Based Model Of Jordan Highland Farmer Decision Making, Phil Selby, Josue Medellin-Azuara, Christian Klassert, Jim Yoon, Julien Harou

International Congress on Environmental Modelling and Software

We build a hydro-economic behavioural model of groundwater irrigated agriculture to help understand and analyse the impact of institutional and biophysical changes on land and water use in the Jordan Highlands. The model sits within a Multi-Agent-Simulation (MAS) framework representing the physical and institutional components of the wider national water resources system, which are being modelled by an interdisciplinary team, including a tanker water market and a groundwater model which interact with the farmer model. The MAS is designed to evaluate climate change scenarios and policy interventions to test whether reform of institutional rules that govern water usage in Jordan …

Evaluating Model Structure Uncertainty By A New Approach To Sensitivity Analysis Utilizing Hydrological Signatures, Jiri Nossent, Mahyar Shafii, Willy Bauwens

International Congress on Environmental Modelling and Software

Model structure uncertainty is one of the most significant sources of uncertainty in traditional hydrological modelling and, above all, challenging to quantify. Structurally flexible models have recently become very popular in hydrology as they tend to allow a reduction of this uncertainty due to their flexibility in the mathematical representation of the hydrological response of a catchment. Reducing structural uncertainty within the flexible framework requires identifying (using top-down or bottom-up approaches) the most suitable (hydrologically consistent) model structure for a given watershed. To assess the models’ hydrological consistency, diagnostic model evaluation techniques are employed to test their capability of reproducing …

Documenting Models For Interoperability And Reusability, Rajbir Parmar, Kurt Wolfe, Gene Whelan, Gerard F. Laniak, Mike Galvin, Jonathan L. Goodall

International Congress on Environmental Modelling and Software

Many modeling frameworks compartmentalize science via individual models that link sets of small components to create larger modeling workflows. Developing integrated watershed models increasingly requires coupling multidisciplinary, independent models, as well as collaboration between scientific communities, since component-based modeling can integrate models from different disciplines. Integrated Environmental Modeling (IEM) systems focus on transferring information between components by capturing a conceptual site model; establishing local metadata standards for input/output of models and databases; managing data flow between models and throughout the system; facilitating quality control of data exchanges (e.g., checking units, unit conversions, transfers between software languages); warning and error handling; …

Water Demand Forecasting With Autoflow© Using State-Space Approach, Khoi Anh Nguyen, Oz Sahin, Rodney Anthony Stewart, Hong Zhang

International Congress on Environmental Modelling and Software

The authors have recently developed an intelligent application, Autoflow©, which is a powerful tool to autonomously categorise residential water consumption data into a registry of single and combined events. This tool was developed using data collected in several cities in Australia, and when applied on standalone properties, the achieved accuracy ranged from 86% and 96% in terms of number of correctly classified events. Taking advantage of the analysis results from Autoflow©, the aim of this study is to propose a short-term water demand forecasting model that not only allows water utilities to predict the overall …

Semantic Data Integration From Multi Linked Model Framework, Binh Thanh Nguyen, Gregor Kiesewetter, Wolfgang Schöpp

International Congress on Environmental Modelling and Software

Model integration is becoming increasingly important due to the requirements for multi-scale and multi-objective assessment and decision making. Moreover, instead of incorporating all complex related information system models that are relevant for different related aspects into one super-model, a multi linked model framework has been proposed to extract data and output from multiple linked models into the coherent data warehouse, which respects the interdependency of data from different model as well as additional knowledge already contained in its existing data cubes.

In this paper, first the multi linked model framework is defined in a very formal manner. The mathematical abstract …

Simulating Structural Change In Agriculture: Modelling Farming Households And Farm Succession, Christian Troost, Thomas Berger

International Congress on Environmental Modelling and Software

The majority of European farms are family farms. Farm succession, i.e. passing over the responsibility from farm owner and manager to their heir, is an important element of structural change in agriculture. We present a model implementation capturing farming household evolution in an agent- based model and explore the consequences of farm household composition and farm succession on agricultural production, investment and participation in agri-environmental policy schemes.

Modelling Combinations Of Economic Instruments To Eliminate Depletion In The Alto Guadalentín Aquifer (Se Spain), David Martínez-Granados, Javier Calatrava

International Congress on Environmental Modelling and Software

This paper analyses the cost-effectiveness of combining several policy instruments to address the problem of non-renewable pumping in the Alto Guadalentín aquifer in Southeast Spain, one of the most extreme cases of aquifer depletion in Europe. Their economic impact is assessed using a partial equilibrium non-linear mathematical programming model that maximises the farm net margin resulting from the use of the available water resources for irrigation in the area. Our results show that all the alternatives have significant economic impacts, although the future availability of desalinised resources would notably mitigate them, as farmers can substitute groundwater with desalinised water. …

Tools And Techniques For Computational Reproducibility, Stephen Piccolo, Michael B. Frampton

Faculty Publications

When reporting research findings, scientists document the steps they followed so that others can verify and build upon the research. When those steps have been described in sufficient detail that others can retrace the steps and obtain similar results, the research is said to be reproducible. Computers play a vital role in many research disciplines and present both opportunities and challenges for reproducibility. Computers can be programmed to execute analysis tasks, and those programs can be repeated and shared with others. The deterministic nature of most computer programs means that the same analysis tasks, applied to the same data, will …

The Effects Of Antenna Coupling In A Mimo Radar System, Benjamin T. Arnold

Theses and Dissertations

A mathematical model for a multiple-input multiple-output radar system is presented. The model is used to track signals through the system in order to identify the impact of antenna array mutual coupling on radar system performance. Simulations using the model provide quantitative assessment of the performance degradation as a function of antenna coupling strength. Specifically, the results show that coupling can cause a target to appear at an angle notably different than its actual angle and can cause an increase in the side lobe level. A compensation technique is presented that completely removes these effects for practical levels of coupling. …

Steady State Configurations Of Cells Connected By Cadherin Sites, Jared Adam Mcbride

Theses and Dissertations

Many cells employ cadherin complexes (c-sites) on the cell membrane to attach to neighboring cells, as well as integrin complexes (i-sites) to attach to a substrate in order to accomplish cell migration. This paper analyzes a model for the motion of a group of cells connected by c-sites. We begin with two cells connected by a single c-site and analyze the resultant motion of the system. We find that the system is irrotational. We present a result for reducing the number of c-sites in a system with c-sites between pairs of cells. This greatly simplifies the general system, and provides …

Emission From Black Holes And Supernovae In The Early Universe, Brandon Kerry Wiggins

Theses and Dissertations

To constrain the era when the first galaxies and stars appeared upcoming instruments will rely on the brightest events in the universe: supernovae and brilliant emission from massive black holes. In this dissertation, we investigate the observability of certain types of supernovae of the very first stars (Population III stars) and find that while these events are sufficiently luminous to be observed with deep-sky instruments such as the James Webb Space Telescope (JWST), they may not observe these particular types of events in their lifetimes. We next explore the origins of massive black holes and introduce the direct collapse hypothesis …

Studies Toward Yaku'amide A And Synthesis And Applications Of Bulky Α,Β-Dehydroamino Acids, Jintao Jiang

Theses and Dissertations

Yaku'amide A shows a unique inhibitory profile against a series of 39 human cancer cell lines (JFCR39). In our efforts to synthesize yaku'amide A, we have optimized our regioselective base-free aminohydroxylation method with a series of nitrogen sources, developed a chiral reagent-mediated aminohydroxylation strategy and chemoselective deprotections of the resulting aminohydroxylation product, and explored a stereospecific E2 dehydration and O-N acyl transfer sequence. In addition, we have prepared the right-hand tetrapeptide and the NTA subunit. For our bulky α,β-dehydroamino acids project, we have developed strategies to incorporate α,β-dehydroamino acids such as ΔVal and ΔEnv into small synthetic peptides via Solid …

Insight Into Student Conceptions Of Proof, Steven Daniel Lauzon

Theses and Dissertations

The emphasis of undergraduate mathematics content is centered around abstract reasoning and proof, whereas students' pre-college mathematical experiences typically give them limited exposure to these concepts. Not surprisingly, many students struggle to make the transition to undergraduate mathematics in their first course on mathematical proof, known as a bridge course. In the process of this study, eight students of varied backgrounds were interviewed before during and after their bridge course at BYU. By combining the proof scheme frameworks of Harel and Sowder (1998) and Ko and Knuth (2009), I analyzed and categorized students’ initial proof schemes, observed their development throughout …

Developmental Changes In Response To Music-Evoked Emotion Among Children And Adolescents With Autism Spectrum Disorders, Kevin G. Stephenson

Theses and Dissertations

Significant symptoms of anxiety in individuals with autism spectrum disorder (ASD) may arise due to impaired emotion recognition. In light of reports showing ASD-specific developmental changes in amygdala volumes, we expanded a previous study of recognition of music-evoked emotions in ASD versus typical controls (CON). We explicitly compared both behavioral and psychophysiological response to music-evoked emotions of children (ages 8-11) and older adolescents (ages 16-18). A total of 91 participants (42 ASD) listened to segments of instrumental music that had been previously validated to evoke happy, sad, or scary emotional valence. We measured accuracy and reaction time while also …

The Quest To Secure Email: A Usability Analysis Of Key Management Alternatives, Jeffrey Thomas Andersen

Theses and Dissertations

The current state of email security is lacking, and the need for end-to-end encryption of email is clear. Recent research has begun to make progress towards usable, secure email for the masses (i.e., novice users without IT support). In this paper, we evaluate the usability implications of three different key management approaches: PGP, IBE, and passwords. Our work is the first formal A/B evaluation of the usability of different key management schemes, and the largest formal evaluation of secure email ever performed. Our results reveal interesting inherent usability trade-offs for each approach to secure email. Furthermore, our research results in …

Group Flow In The Byu Animation Studio, Jana Lynn Duncan

Theses and Dissertations

This dissertation encompasses three articles concerning Sawyer's (2007) theory of group flow in the context of higher education, including a literature review, and two interpretive studies. In the literature review and in the first interpretive research article, the results of the research illuminated the applicability of themes of group flow in collaborative settings in higher education in themes of vision, ownership and contribution, and communication. The final article provides a description of the roles of student lead and professor in this environment and the unique ways that they may have encouraged those themes in the studio. The context for this …

Gas Phase Structure Characterization Using Fourier Transform Ion Cyclotron Resonance Mass Spectrometry, Anupriya Anupriya

Theses and Dissertations

This dissertation investigates Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) based techniques to study the impact of molecular structure on conformation and binding energetics. A novel method to determine collison cross sectional areas using FTICR (CRAFTI), initially developed by the Dearden lab, was applied to study the conformations of molecular systems with unique structural attributes in an attempt to explore the molecular range of CRAFTI. The systems chosen for CRAFTI studies include crown-ether alkylammonium complexes and biogenic amino acids. The results were found to be consistent with expected behavior, and strongly correlated with experimental measurements made using ion mobility …

Computational Studies Of Alkane C-H Functionalization By Main-Group Metals, Samantha Jane Gustafson

Theses and Dissertations

The most efficient homogeneous catalysts for hydroxylation of light alkanes utilize transition metals in superacid solvent and operate by tandem electrophilic C-H activation/metal-alkyl (M-R) functionalization. An emerging alternative strategy to transition metals is the use of high-oxidation state main-group metals (e.g. TlIII, PbIV, IIII) that hydroxylate light alkanes. This dissertation reports density-functional theory calculations that reveal the mechanisms, reactivity, and selectivity of TlIII promoted alkane C-H functionalization in trifluoroacetic acid and TlIII-dialkyl functionalization in water. Calculations reveal that TlIII oxidizes alkanes via a closed-shell C-H activation and M-R functionalization mechanism that is similar to transition-metal C-H functionalization mechanisms. Comparison of …