Physical Sciences and Mathematics Commons^™

Land Use, Power, And Knowledge At The Northern Resource Frontier: Mining, Public Engagement, And Contentious Land Imaginaries In Bristol Bay And The Yukon-Kuskokwim Delta, Jonathan Tollefson

Graduate College Dissertations and Theses

The Donlin and Pebbles mines are two of the eight industrial-scale hard rock mines currently under the review of Alaska’s Large Mine Permitting program. Both projects promise to deliver profit and employment to their respective regions: Pebble to Bristol Bay in the southwest, and Donlin to the Yukon-Kuskokwim Delta, just north of Pebble. Both projects would also produce exceptional quantities of waste and will require almost-unprecedented infrastructure development, potentially threatening the lives and subsistence livelihoods of the Alaska Native peoples in their respective regions. The Pebble project inspired international protest and led to the emergence of a powerful resistance coalition …

Microscale Controls On Lead Speciation In Soils: A Framework For Sustainable Remediation, Grant Reeder

Graduate College Dissertations and Theses

The potential of a soil to immobilize heavy metal ions is dependent on the presence of adsorption sites, and the stability of metal species over the range of geochemical conditions present in the soil over time. Lead (Pb) is a cumulative toxin that is enriched in much of the urban pedosphere due to historical use of Pb-based paint and Pb-amended gasoline. Because in-situ remediation of Pb is possible if the bioavailable fraction can be rendered inert, understanding Pb-sorbent interactions is necessary to accurately and efficiently alter Pb speciation in soils. The objectives of this study are to 1) determine efficient …

Soil Aggregates: The Mechanistic Link To Increased Dissolved Organic Carbon In Surface Waters?, Malayika Cincotta

Graduate College Dissertations and Theses

Dissolved organic carbon (DOC) plays an important role in the global carbon (C) cycle because increases in aqueous C potentially contribute to rising atmospheric CO2 levels. Over the past few decades, headwater streams of the northern hemisphere have shown increased amounts of DOC coinciding with decreased acid deposition. Although the issue is widely discussed in the literature, a mechanistic link between precipitation composition and stream water DOC has not yet been proposed.

In this study, the breakup of soil aggregates is hypothesized as the mechanistic link between reduced acid deposition and DOC increases in surface waters. Specific hypotheses state that …

Structurally Defined Conditional Data-Flow Static Analysis, Elena Sherman, Matthew B. Dwyer

Computer Science Faculty Publications and Presentations

Data flow analysis (DFA) is an important verification technique that computes the effect of data values propagating over program paths. While more precise than flow-insensitive analyses, such an analysis is time-consuming.

This paper investigates the acceleration of DFA by structural decomposition of the underlying control flow graph. Specifically, we explore the cost and effectiveness of dividing program paths into subsets by partitioning path suffixes at conditional statements, applying a DFA on each subset, and then combining the resulting invariants. This yields a family of independent DFA problems that are solved in parallel and where the partial results of each problem …

The Lkpy Package For Recommender Systems Experiments, Michael D. Ekstrand

Computer Science Faculty Publications and Presentations

Since 2010, we have built and maintained LensKit, an open-source toolkit for building, researching, and learning about recommender systems. We have successfully used the software in a wide range of recommender systems experiments, to support education in traditional classroom and online settings, and as the algorithmic backend for user-facing recommendation services in movies and books. This experience, along with community feedback, has surfaced a number of challenges with LensKit’s design and environmental choices. In response to these challenges, we are developing a new set of tools that leverage the PyData stack to enable the kinds of research experiments and educational …

Retrieving And Recommending For The Classroom: Stakeholders, Objectives, Resources, And Users, Michael D. Ekstrand, Ion Madrazo Azpiazu, Katherine Landau Wright, Maria Soledad Pera

Computer Science Faculty Publications and Presentations

In this paper, we consider the promise and challenges of deploying recommendation and information retrieval technology to help teachers locate resources for use in classroom instruction. The classroom setting is a complex environment presenting a number of challenges for recommendation, due to its inherent multi-stakeholder nature, the multiple objectives that quality educational resources and experiences must simultaneously satisfy, and potential disconnect between the direct user of the system and the end users of the resources it provides. In this paper, we outline these challenges, highlight opportunities for new research, and describe our work in progress in this area including insights …

Investigating Query Formulation Assistance For Children, Oghenemaro Anuyah, Maria Soledad Pera, Jerry Alan Fails

Computer Science Faculty Publications and Presentations

Popular tools used to search for online resources are tuned to satisfy a broad category of users—primarily adults. Because children have specific needs, these tools may not always be successful in offering the right level of support in their quest for information. While search tools often provide query assistance, children still face many difficulties expressing their information needs in the form of a query. In this paper, we share results from our ongoing research work focused on understanding children's interactions with query suggestions and their preferences with respect to suggestions offered by a general-purpose strategy versus a counterpart designed exclusively …

Exploring Author Gender In Book Rating And Recommendation, Michael D. Ekstrand, Mucun Tian, Mohammed R. Imran Kazi, Hoda Mehrpouyan, Daniel Kluver

Computer Science Faculty Publications and Presentations

Collaborative filtering algorithms find useful patterns in rating and consumption data and exploit these patterns to guide users to good items. Many of the patterns in rating datasets reflect important real-world differences between the various users and items in the data; other patterns may be irrelevant or possibly undesirable for social or ethical reasons, particularly if they reflect undesired discrimination, such as gender or ethnic discrimination in publishing. In this work, we examine the response of collaborative filtering recommender algorithms to the distribution of their input data with respect to a dimension of social concern, namely content creator gender. Using …

From Recommendation To Curation: When The System Becomes Your Personal Docent, Nevena Dragovic, Ion Madrazo Azpiazu, Maria Soledad Pera

Computer Science Faculty Publications and Presentations

Curation is the act of selecting, organizing, and presenting content. Some applications emulate this process by turning users into curators, while others use recommenders to select items, seldom achieving the focus or selectivity of human curators. We bridge this gap with a recommendation strategy that more closely mimics the objectives of human curators. We consider multiple data sources to enhance the recommendation process, as well as the quality and diversity of the provided suggestions. Further, we pair each suggestion with an explanation that showcases why a book was recommended with the aim of easing the decision making process for the …

2nd Fatrec Workshop: Responsible Recommendation, Toshihiro Kamishima, Pierre-Nicolas Schwab, Michael D. Ekstrand

Computer Science Faculty Publications and Presentations

The second Workshop on Responsible Recommendation (FATREC 2018) was held in conjunction with the 12th ACM Conference on Recommender Systems on October 6th, 2018 in Vancouver, Canada. This full-day workshop brought together researchers and practitioners to discuss several topics under the banner of social responsibility in recommender systems: fairness, accountability, transparency, privacy, and other ethical and social concerns.

Predicting Perceived Age: Both Language Ability And Appearance Are Important, Sarah Plane, Ariel Marvasti, Tyler Egan, Casey Kennington

Computer Science Faculty Publications and Presentations

When interacting with robots in a situated spoken dialogue setting, human dialogue partners tend to assign anthropomorphic and social characteristics to those robots. In this paper, we explore the age and educational level that human dialogue partners assign to three different robotic systems, including an un-embodied spoken dialogue system. We found that how a robot speaks is as important to human perceptions as the way the robot looks. Using the data from our experiment, we derived prosodic, emotional, and linguistic features from the participants to train and evaluate a classifier that predicts perceived intelligence, age, and education level.

Probing The Nature Of Student Reasoning Using Modified Chaining Tasks, Ryan Moyer

Honors College

Research-based materials developed by the physics education research community have helped improve student conceptual understanding in introductory physics courses. A growing body of work, however, suggests that poor student performance on certain physics tasks, even after research-based instruction, may result from the nature of student reasoning itself than from conceptual difficulties. Drawing upon dual-process theories of reasoning, it has been argued that some of the poor performance from the presence of salient distracting features (SDFs) in physics problems, which may cue an incorrect first-available mental model and effectively preclude the student from drawing upon relevant knowledge.

In this study, we …

Characterization Of Tetraethyl Orthosilicate-Based Dynamic Hydrogels For Use As Reversible 3-D Cell Culture Matrices, Krisitan Stipe

Graduate Student Theses, Dissertations, & Professional Papers

No abstract provided.

The Effect Of The State Giant Traveling Map Of Montana On The Geographic Literacy Of Fourth Graders In Western Montana, Rebecca A. Kranitz

Graduate Student Theses, Dissertations, & Professional Papers

A complex set of factors and processes operating within the United States public education system contribute to high rates of geographic illiteracy in the majority of young adults. These factors include, but are not limited to, a lack of structured federal controls over state geography requirements, insufficient time to implement effective geography curricula, and inadequate assessment techniques. To raise rates of geographic literacy, the National Geographic Society (NGS) created the State Giant Traveling Maps (SGTM) to actively engage students in a geography education experience that simultaneously promotes positive attitudes towards geography while strengthening student map skills. The SGTMs incorporate a …

Watered Down: The Challenges Of Managing Water Resources In Montana, Beau E. Baker

Graduate Student Theses, Dissertations, & Professional Papers

Like much of the American West, Montana sits in the cross hairs of climate change. State drought resiliency projects and cooperative watershed management are on the rise in the face of decreased snowpack, early runoff, precipitation variability and lower seasonal stream flows. Population growth, land use practices, recreation and tourism all contribute to pressures on state water supplies.

Montana is faced with the arrival of invasive species that threaten the ecological health of its lakes, rivers and streams. State budget constraints and depressed agency capacity are hurting our ability to fend off these threats. There’s a lack of public education …

Meat Reimagined: The Ethics Of Cultured Meat, Valan Anthos

Graduate Student Theses, Dissertations, & Professional Papers

In this paper I explore a relatively new technology that is being developed to try and solve some of the major issues with modern animal agriculture called cultured meat. I cover the short history of this technology and where it is at currently before addressing two different ways of evaluating the ethics of cultured meat. Responding to much of the praise for cultured meat based on consequentialist ethics, I lay out reasons for skepticism and how some of these estimates might be overblown due to those people advocating for it being situated in the ideology of ecomodernism. I argue that …

Facies Architecture And Controls On Reservoir Behavior In The Turonian Wall Creek Member Of The Frontier Formation, Powder River Basin, Wyoming, Nathan M. La Fontaine

Graduate Student Theses, Dissertations, & Professional Papers

Inter-well heterogeneities influencing fluid migration in deltaic reservoirs are controlled by lateral lithofacies changes and vertical complexities such as low permeability thin-beds. Subsurface tools often cannot predict the spatial and stratigraphic organization of these architectural elements, nor their influence on effective reservoir properties and connectivity. This study integrates sedimentological, stratigraphic, and fluid simulation data to 1) document the facies architecture and depositional evolution of the Turonian Wall Creek Member (WCM) of the Frontier Formation, and 2) quantify the role of multi-scale stratigraphic heterogeneity on reservoir behavior. Upscaled permeability properties derived from fluid simulation of nested, small-scale facies models condition the …

Predictive Spatial Modeling Of Wildfire Occurrence And Poaching Events Related To Siberian Tiger Conservation In Southwest Primorye, Russian Far East, Conor N. Phelan

Graduate Student Theses, Dissertations, & Professional Papers

Siberian tiger (Panthera tigris altaica) populations worldwide have been drastically reduced in number over the past several decades. The Primorye region of the Russian Far East remains one of the final strongholds for the estimated 400 Siberian tigers remaining in the wild. As a flagship species, Siberian tigers play a crucial socio-economic role in helping agencies and non-profits to motivate, fund, and implement broader conservation efforts. Even while defended by organizations such as the Wildlife Conservation Society (WCS), Siberian tigers in Primorye face an onslaught of threats to their continued existence. Profound land use changes due to the …

The Development Of A Simplified Alkalinity Titration Analyzer, Reba Van Beusekom

Graduate Student Theses, Dissertations, & Professional Papers

Alkalinity is the acid neutralizing capacity for water, meaning alkalinity measures how sensitive an aquatic system is to acidic inputs. Currently, there are various measuring systems for alkalinity available including chemical test kits, potentiometric techniques, and colorimetric methods. Commercially available products lack the ease of use combined with precision and accuracy desired for on-line process and environmental monitoring. The goal of this project is to develop a simplified alkalinity titration analyzer, called the easyTMT, to measure alkalinity with precision and accuracy comparable to the best conventional methods. The system, under development, uses the Tracer Monitored Titration (TMT) technique. TMT …

Quantifying Effects Of Using Thermally Thin Fuel Approximations On Modelling Fire Propagation In Woody Fuels, David Blasen, Jesse Johnson, William Jolly, Russell Parsons

Graduate Student Theses, Dissertations, & Professional Papers

In this paper, we quantify the effects of the thermally thin fuel approximations commonly made in numerical models that eliminate temperature gradients within a heated object. This assumption is known to affect the modeled ignition and burn behavior, but there is little research on its impact, particularly in larger fuels or in numerical models including moisture and chemical decomposition of fuels.

We begin by comparing modeled to observed ignition times and burn rates. To constrain variability in the material properties of wood and focus on variability caused by fuels assumed to be thermally thin, we conduct experiments using thermogravimetric analysis …

Effect Of Neuromodulation Of Short-Term Plasticity On Information Processing In Hippocampal Interneuron Synapses, Elham Bayat Mokhtari

Graduate Student Theses, Dissertations, & Professional Papers

Neurons convey information about the complex dynamic environment in the form of signals. Computational neuroscience provides a theoretical foundation toward enhancing our understanding of nervous system. The aim of this dissertation is to present techniques to study the brain and how it processes information in particular neurons in hippocampus.

We begin with a brief review of the history of neuroscience and biological background of basic neurons. To appreciate the importance of information theory, familiarity with the information theoretic basics is required, these basics are presented in Chapter 2. In Chapter 3, we use information theory to estimate the amount of …

Insights Into The Proterozoic To Cretaceous Evolution Of The Western Clearwater Metamorphic Core Complex, Northern Idaho, Through Petrologic And Geochronologic Analysis, Nora Dwyer

Graduate Student Theses, Dissertations, & Professional Papers

The Clearwater metamorphic core complex (CMCC) in northern Idaho contains a rare exposure of the contact of the basal section of the Mesoproterozoic Belt Supergroup with underlying Paleoproterozoic basement. Prior to this study, this contact had not been well documented. In addition, the rocks within the CMCC preserve a complex history of metamorphism, including both Mesoproterozoic and Cretaceous-Eocene regional events. Detrital zircon analysis of five coarsely recrystallized, clean quartzite samples at this contact reveal a bimodal age distribution with peaks at around 1800 - 1900 Ma and 2650 Ma. Several grains are younger than 1700 Ma, with the youngest being …

Evaluation Of Autonomously Measured Alkalinity, Ph, And Pco2 Variability On A Coral Reef, Brittany Peterson

Graduate Student Theses, Dissertations, & Professional Papers

Currently, our understanding of alkalinity (A_T) variability in highly dynamic environments such as coral reefs is limited by the dearth of A_T measurements. In order to better characterize these environments, high temporal resolution A_T data are needed. This work employed the newly developed Submersible Autonomous Moored Instrument for Alkalinity (SAMI-alk), a fully autonomous in situ A_T analyzer, to study seawater A_T variability. The main goals of this research were to evaluate the utility of combining the SAMI-alk data with currently available in situ measurements of pH and partial pressure of carbon dioxide (p …

An Interdisciplinary Approach To The Target Elucidation Of Novel Antibiotic 31g12, Larissa A. Walker

Graduate Student Theses, Dissertations, & Professional Papers

Staphylococcus aureus is a Gram-positive bacterial pathogen responsible for nosocomial and community-acquired infections that can quickly acquire antibiotic resistance. We have identified a novel triazole antimicrobial 31G12 based on the natural product core of nonactin isolated from the fermentation of Streptomyces griseus, that is active against many Gram-positive bacteria as well as antibiotic resistant methicillin-resistant S. aureus and vancomycin-resistant Enterococcus. The synthesis and characterization indicate that 31G12 exists as a mixture of two rotamers at room temperature and displays bacteriostatic activity against S. aureus with moderate mammalian cell toxicity. We have currently identified potential protein targets of 31G12 in …

Large-Scale Photovoltaic Solar Implementation: Montanan Stakeholder Opportunities And Challenges, Erika Mickelson

Graduate Student Theses, Dissertations, & Professional Papers

Large-scale photovoltaic (PV) solar projects were operationalized in the 1990s resulting in a plethora of studies focusing on environmental, economic, technological, and policy studies. Minimal research investigates the similarities and differences between conveners using PV solar technology. This case study evaluates stakeholder perceptions regarding project management, project design, and external factors influencing the success of large-scale PV solar projects convened by a qualifying facility, regional utility company, and electric co-operative in Montana. Respondents revealed concepts were similar across conveners; yet, emphasized unique implications for each convener. The results indicated the importance for all conveners to incorporate marketing strategies, local interests …

Collaboration Patterns In Software Developer Network, Didi Surian, Ee-Peng Lim, David Lo

Research Collection School Of Computing and Information Systems

In this entry, we mine collaboration patterns from a large software developer network (Surian et al. 2010). We consider high- and low-level patterns. High-level patterns correspond to various network-level statistics that we observe to hold in this network. Low-level patterns are topological subgraph patterns that are frequently observed among developers collaborating in the network. Mining topological subgraph patterns are difficult as it is an NP-hard problem. To address this issue, we use a combination of frequent subgraph mining and graph matching by leveraging the power law property exhibited by a large collaboration graph. The technique is applicable to any software …

Discriminant Analysis On Riemannian Manifold Of Gaussian Distributions For Face Recognition With Image Sets, W. Wang, R. Wang, Zhiwu Huang, S. Shan, X. Chen

Research Collection School Of Computing and Information Systems

To address the problem of face recognition with image sets, we aim to capture the underlying data distribution in each set and thus facilitate more robust classification. To this end, we represent image set as the Gaussian mixture model (GMM) comprising a number of Gaussian components with prior probabilities and seek to discriminate Gaussian components from different classes. Since in the light of information geometry, the Gaussians lie on a specific Riemannian manifold, this paper presents a method named discriminant analysis on Riemannian manifold of Gaussian distributions (DARG). We investigate several distance metrics between Gaussians and accordingly two discriminative learning …

Modeling Engagement Of Programming Students Using Unsupervised Machine Learning Technique, Hua Leong Fwa, Lindsay Marshall

Research Collection School Of Computing and Information Systems

Engagement is instrumental to students’ learning and academic achievements. In this study, we model the engagement states of students who are working on programming exercises in an intelligent tutoring system. Head pose, keystrokes and action logs of students automatically captured within the tutoring system are fed into a Hidden Markov Model for inferring the engagement states of students. With the modeling of students’ engagement on a moment by moment basis, intervention measures can be initiated automatically by the system when necessary to optimize the students’ learning. This study is also one of the few studies that bypass the need for …

Secure Smart Metering Based On Lora Technology, Yao Cheng, Hendra Saputra, Leng Meng Goh, Yongdong Wu

Research Collection School Of Computing and Information Systems

Smart metering allows Substation Automation System (SAS) to remotely and timely read smart meters. Despite its advantages, smart metering brings some challenges. a) It introduces cyber attack risks to the metering system, which may lead to user privacy leakage or even the compromise of smart metering systems. b) Although the majority of meters are located within a regional power supply area, some hard-to-reach nodes are geographically far from the clustered area, which account for a big portion of the entire smart metering operation cost. Facing the above challenges, we propose a secure smart metering infrastructure based on LoRa technology which …

Efficient And Privacy-Preserving Outsourced Calculation Of Rational Numbers, Ximeng Liu, Kim-Kwang Raymond Choo, Robert H. Deng, Rongxing Lu, Jian Weng

Research Collection School Of Computing and Information Systems

In this paper, we propose a framework for efficient and privacy-preserving outsourced calculation of rational numbers, which we refer to as POCR. Using POCR, a user can securely outsource the storing and processing of rational numbers to a cloud server without compromising the security of the (original) data and the computed results. We present the system architecture of POCR and the associated toolkits required in the privacy preserving calculation of integers and rational numbers to ensure that commonly used outsourced operations can be handled on-the-fly. We then prove that the proposed POCR achieves the goal of secure integer and rational …