Physical Sciences and Mathematics Commons^™

Addressing The Issues Of Drug Delivery Via Advanced Macromolecular Design, Brooks Allen Abel

Dissertations

The work described in this dissertation focuses on the development of synthetic approaches toward novel polymer architectures that specifically address the issues of in vivo drug delivery. Successful implementation of the synthetic methodologies described herein required fundamental investigations into the underlying chemistries in ways that now provide greater insights into the nature of the these chemical reactions.

In Section I, the synthesis of tunable pH- and CO₂-responsive sulfonamide-containing polymers using reversible addition-fragmentation chain transfer (RAFT) polymerization is described. Initially, poor polymerization control of methacryloyl sulfonamide (MSA) monomers was observed using traditional RAFT polymerization conditions. Ultimately, reducing the polymerization …

Ecological Niche Modeling Of The North American Giant Salamander: Predicting Current And Future Potential Distributions And Examining Environmental Influences, Selena S. Roark

Electronic Theses and Dissertations

North American Giant Salamanders (Cryptobranchus alleganiensis), commonly known as hellbenders, have been experiencing a population decline for decades due to human influences, such as pollution and habitat destruction. Many efforts are underway to save the hellbender but their entire potential geographical range has not been well-studied. Currently, hellbender populations are delineated by county boundaries and are on the International Union for Conservation of Nature Red List. The Genetic Algorithm for Rule-set Production, an Ecological Niche Model, was used to model the current hellbender potential distribution at a macro-scale under two different environmental scenarios. Additionally, future potential distributions were …

An Autonomous Agent For Learning Spatiotemporal Models Of Human Daily Activities, Shan Gao, Ah-Hwee Tan

Research Collection School Of Computing and Information Systems

Activities of Daily Living (ADLs) refer to activities performed by individuals on a daily basis. As ADLs are indicatives of a person’s habits, lifestyle, and well being, learning the knowledge of people’s ADL routine has great values in the healthcare and consumer domains. In this paper, we propose an autonomous agent, named Agent for Spatia-Temporal Activity Pattern Modeling (ASTAPM), being able to learn spatial and temporal patterns of human ADLs. ASTAPM utilises a self-organizing neural network model named Spatiotemporal - Adaptive Resonance Theory (ST-ART). ST-ART is capable of integrating multimodal contextual information, involving the time and space, wherein the ADL …

Euclidean Co-Embedding Of Ordinal Data For Multi-Type Visualization, Dung D. Le, Hady W. Lauw

Research Collection School Of Computing and Information Systems

Embedding deals with reducing the high-dimensional representation of data into a low-dimensional representation. Previous work mostly focuses on preserving similarities among objects. Here, not only do we explicitly recognize multiple types of objects, but we also focus on the ordinal relationships across types. Collaborative Ordinal Embedding or COE is based on generative modelling of ordinal triples. Experiments show that COE outperforms the baselines on objective metrics, revealing its capacity for information preservation for ordinal data.

Simultaneous Optimization And Sampling Of Agent Trajectories Over A Network, Hala Mostafa, Akshat Kumar, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

We study the problem of optimizing the trajectories of agents moving over a network given their preferences over which nodes to visit subject to operational constraints on the network. In our running example, a theme park manager optimizes which attractions to include in a day-pass to maximize the pass’s appeal to visitors while keeping operational costs within budget. The first challenge in this combinatorial optimization problem is that it involves quantities (expected visit frequencies of each attraction) that cannot be expressed analytically, for which we use the Sample Average Approximation. The second challenge is that while sampling is typically done …

Approximate Inference Using Dc Programming For Collective Graphical Models, Duc Thien Nguyen, Akshat Kumar, Hoong Chuin Lau, Daniel Sheldon

Research Collection School Of Computing and Information Systems

Collective graphical models (CGMs) provide a framework for reasoning about a population of independent and identically distributed individuals when only noisy and aggregate observations are given. Previous approaches for inference in CGMs work on a junction-tree representation, thereby highly limiting their scalability. To remedy this, we show how the Bethe entropy approximation naturally arises for the inference problem in CGMs. We reformulate the resulting optimization problem as a difference-of-convex functions program that can capture different types of CGM noise models. Using the concave-convex procedure, we then develop a scalable message-passing algorithm. Empirically, our approach is highly scalable and accurate for …

Mobile Big Data Analytics Using Deep Learning And Apache Spark, Mohammad Abu Alsheikh, Dusit Niyato, Shaowei Lin, Hwee-Pink Tan, Zhu Han

Research Collection School Of Computing and Information Systems

The proliferation of mobile devices, such as smartphones and Internet of Things gadgets, has resulted in the recent mobile big data era. Collecting mobile big data is unprofitable unless suitable analytics and learning methods are utilized to extract meaningful information and hidden patterns from data. This article presents an overview and brief tutorial on deep learning in mobile big data analytics and discusses a scalable learning framework over Apache Spark. Specifically, distributed deep learning is executed as an iterative MapReduce computing on many Spark workers. Each Spark worker learns a partial deep model on a partition of the overall mobile, …

Graph-Aided Directed Testing Of Android Applications For Checking Runtime Privacy Behaviours, Joseph Joo Keng Chan, Lingxiao Jiang, Kiat Wee Tan, Rajesh Krishna Balan

Research Collection School Of Computing and Information Systems

While automated testing of mobile applications is very useful for checking run-time behaviours and specifications, its capability in discovering issues in apps is often limited in practice due to long testing time. A common practice is to randomly and exhaustively explore the whole app test space, which takes a lot of time and resource to achieve good coverage and reach targeted parts of the apps. In this paper, we present MAMBA, a directed testing system for checking privacy in Android apps. MAMBA performs path searches of user events in control-flow graphs of callbacks generated from static analysis of app bytecode. …

Mining Social Ties Beyond Homophily, Hongwei Liang, Ke Wang, Feida Zhu

Research Collection School Of Computing and Information Systems

Summarizing patterns of connections or social tiesin a social network, in terms of attributes information on nodesand edges, holds a key to the understanding of how the actorsinteract and form relationships. We formalize this problem asmining top-k group relationships (GRs), which captures strongsocial ties between groups of actors. While existing works focuson patterns that follow from the well known homophily principle,we are interested in social ties that do not follow from homophily,thus, provide new insights. Finding top-k GRs faces new challenges:it requires a novel ranking metric because traditionalmetrics favor patterns that are expected from the homophilyprinciple; it requires an innovative …

Generalized Reciprocal Identities, Timothy Huber, Daniel Schultz

School of Mathematical & Statistical Sciences Faculty Publications

Included in Ramanujan’s Notebooks are two reciprocal identities. The first identity connects the Rogers-Ramanujan continued fraction with an eta quotient. The second identity is a level thirteen analogue. These are special cases of a more general class of relations between eta quotients and modular functions defined by product generalizations of the Rogers-Ramanujan continued fraction. Each identity is shown to be a relation between generators for a certain congruence subgroup. The degree, form, and symmetry of the identities is determined from behavior at cusps of the congruence subgroup whose field of functions the parameters generate. The reciprocal identities encode information about …

Barriers To Initiation Of Open Source Software Projects In Research Libraries, Jason Curtis Thacker

Theses and Dissertations

Libraries share a number of core values with the Open Source Software (OSS) movement, suggesting there should be a natural tendency toward library participation in OSS projects. However, Dale Askey's 2008 Code4Lib column entitled We Love Open Source Software. No, You Can't Have Our Code, claims that while libraries are strong proponents of OSS, they are unlikely to actually contribute to OSS projects. He identifies, but does not empirically substantiate, six barriers that he believes contribute to this apparent inconsistency. The goal of this thesis is to empirically investigate not only Askey's central claim but also the six barriers he …

Intelligent Pen: A Least Cost Search Approach To Stroke Extraction In Historical Documents, Kevin L. Bauer

Theses and Dissertations

Extracting strokes from handwriting in historical documents provides high-level features for the challenging problem of handwriting recognition. Such handwriting often contains noise, faint or incomplete strokes, strokes with gaps, overlapping ascenders and descenders and competing lines when embedded in a table or form, making it unsuitable for local line following algorithms or associated binarization schemes. We introduce Intelligent Pen for piece-wise optimal stroke extraction. Extracted strokes are stitched together to provide a complete trace of the handwriting. Intelligent Pen formulates stroke extraction as a set of piece-wise optimal paths, extracted and assembled in cost order. As such, Intelligent Pen is …

An Analyzer For Message Passing Programs, Yu Huang

Theses and Dissertations

Asynchronous message passing systems are fast becoming a common means for communication between devices. Two problems existing in message passing programs are difficult to solve. The first problem, intended or otherwise, is message-race where a receive may match with more than one send in the runtime system. This non-determinism often leads to intermittent and unexpected behavior depending on the resolution of the race. Another problem is deadlock, which is a situation in that each member process of the group is waiting for some member process to communicate with it, but no member is attempting to communicate with it. Detecting if …

Graphical Narrative Interfaces: Representing Spatiotemporal Information For A Human-Robot Team With A Highly Autonomous Robot, Hiroaki Nakano

Theses and Dissertations

Having a well-developed Graphical User Interface (GUI) is often necessary for a human-robot team, especially when the human and the robot are not in close proximity to each other or when the human does not interact with the robot in real time. Most current GUIs process and display information in real time, but the time to interact with these systems does not scale well when the complexity of the displayed information increases or when information must be fused to support decision-making. We propose a new interface concept, a Graphical Narrative Interface (GNI), which presents story-based summaries driven by accumulated data. …

The Social Side Of Software Platform Ecosystems, Cleidson R. B. Da Souza, Fernando Figueira Filho, Müller Miranda, Renato Pina Ferreira, Christoph Treude, Leif Singer

Research Collection School Of Computing and Information Systems

Software ecosystems as a paradigm for large-scale software development encompass a complex mix of technical, business, and social aspects. While significant research has been conducted to understand both the technical and business aspects, the social aspects of software ecosystems are less well understood. To close this gap, this paper presents the results of an empirical study aimed at understanding the influence of social aspects on developers’ participation in software ecosystems. We conducted 25 interviews with mobile software developers and an online survey with 83 respondents from the mobile software development community. Our results point out a complex social system based …

Capture: A New Predictive Anti-Poaching Tool For Wildlife Protection, Thanh H. Nguyen, Arunesh Sinha, Shahrzad Gholami, Andrew Plumptre, Lucas Joppa, Milind Tambe, Margaret Driciru, Fred Wanyama, Aggrey Rwetsiba, Rob Critchlow

Research Collection School Of Computing and Information Systems

Wildlife poaching presents a serious extinction threat to many animalspecies. Agencies (“defenders”) focused on protecting suchanimals need tools that help analyze, model and predict poacheractivities, so they can more effectively combat such poaching; suchtools could also assist in planning effective defender patrols, buildingon the previous security games research.To that end, we have built a new predictive anti-poaching tool,CAPTURE (Comprehensive Anti-Poaching tool with Temporaland observation Uncertainty REasoning). CAPTURE providesfour main contributions. First, CAPTURE’s modeling of poachersprovides significant advances over previous models from behavioralgame theory and conservation biology. This accounts for:(i) the defender’s imperfect detection of poaching signs; (ii) complextemporal dependencies in …

Approximating The Performance Of A "Last Mile" Transportation System, Hai Wang, Amedeo Odoni

Research Collection School Of Computing and Information Systems

The Last Mile Problem (LMP) refers to the provision of travel service from the nearest public transportation node to a home or office. We study the supply side of this problem in a stochastic setting, with batch demands resulting from the arrival of groups of passengers who request last-mile service at urban rail stations or bus stops. Closedform approximations are derived for the performance of Last Mile Transportations Systems as a function of the fundamental design parameters of such systems. An initial set of results is obtained for the case in which a fleet of vehicles of unit capacity provides …

Zephyr: A Social Psychology-Based Mobile Application For Long-Distance Romantic Partners, Dhiraj Bodicherla

Open Access Theses

Long-distance romantic relationships have become quite common nowadays. With CMC tools advancing day-by-day, their usage among LDRs is proliferating rapidly. Attachment-related anxiety and avoidance can block the ability to enjoy happy relationships. During such situations, remembering happy past moments can be comforting. In this study a mobile chat application that enables LDR couples to reminisce about happy moments was developed. This study primarily focuses on evaluating the usability of this mobile application using survey-based methods. System Usability Scale was considered to discuss the outcome of the study. The overall results provide useful recommendations for further improvements in the design of …

Drinking Water Treatment: Salt-Free Water “Softener” Options, Bruce I. Dvorak

Department of Civil and Environmental Engineering: Faculty Publications

New no-salt technologies may be effective in treating hard water, but consumers should carefully investigate product claims prior to buying a specific treatment device.

Hard water is not a health risk, but many Nebraska consumers find hard water to be a nuisance because of mineral buildup on plumbing fixtures, including water heaters; unsightly film on glass and crystal wares; and poor soap and/or detergent performance. Water described as “hard” contains high amounts of dissolved calcium and magnesium, which are positively charged contaminants called cations.

Water hardness often is expressed as grains of hardness per gallon of water (gpg) or milligrams …

Stomatal Differences In Western Aspen And Linkage To Drought Tolerance, Brianne Palmer

Undergraduate Honors Capstone Projects

Aspen (Populus tremuloides) is the most widely distributed broadleaf forest tree in North America. However, aspen are declining rapidly in areas of the Intermountain West. Aspen in this area are prone to experiencing limited moisture and high temperatures. An important aspect of plant physiology when dealing with these stressors is stomatal function. Stomata control the rate of photosynthesis, therefore, the size and frequency of the stomata is likely to influence the survival of the species in this environment.

An unusual feature of aspen is the high frequency of triploidy in the southern portion of its range. Stomata! size …

The Effect Of Pure Infrared Light On The Growth Of Rhodospirrilum Rubrum, Jordan Lee Wilkes

Undergraduate Honors Capstone Projects

Scientists who study aquatic ecosystems quickly notice a diversity of pathways that different microbes and organisms can use to metabolize nutrients found in common ponds or pools. Competition for vital resources, such as light and inorganic minerals, allow only certain organisms to grow in certain niches within these ecosystems. Rhodospirillum rubrum is a gram negative, photosynthetic bacteria that competes for light within aquatic ecosystems in order to survive. R. rubrum is believed to specifically absorb light for photosynthesis at wavelengths in the range of infrared light. It was found that R. rubrum indeed can grow in "dark", anaerobic environments by …

From Lights Out To Lights On, Ravi Chidambaram

Asian Management Insights

How Sunlabob went from providing affordable, sustainable energy in rural Laos to becoming an international turnkey operator and co-developer.

Information Overload In Structured Data, Pinar Yanardag Delul

Open Access Dissertations

Information overload refers to the difficulty of making decisions caused by too much information. In this dissertation, we address information overload problem in two separate structured domains, namely, graphs and text.

Graph kernels have been proposed as an efficient and theoretically sound approach to compute graph similarity. They decompose graphs into certain sub-structures, such as subtrees, or subgraphs. However, existing graph kernels suffer from a few drawbacks. First, the dimension of the feature space associated with the kernel often grows exponentially as the complexity of sub-structures increase. One immediate consequence of this behavior is that small, non-informative, sub-structures occur more …

Homological Properties Of Determinantal Arrangements, Arnold H. Yim

Open Access Dissertations

We study a certain family of hypersurface arrangements known as determinantal arrangements. Determinantal arrangements are a union of varieties defined by minors of a matrix of indeterminates. In particular, we investigate determinantal arrangements using the 2-minors of a 2 × n generic matrix (which can be thought of as natural extensions of braid arrangements), and prove certain statements about their freeness. We also study the topology of these objects. We construct a fibration for the complement of free determinantal arrangements, and use this fibration to prove statements about their homotopy groups. Furthermore, we show that the Poincaré polynomial of the …

Investigation Of Climate Variability And Climate Change Impacts On Corn Yield In The Eastern Corn Belt, Usa, Ruoyu Wang

Open Access Dissertations

The increasing demand for both food and biofuels requires more corn production at global scale. However, current corn yield is not able to meet bio-ethanol demand without jeopardizing food security or intensifying and expanding corn cultivation. An alternative solution is to utilize cellulose and hemi-cellulose from perennial grasses to fulfill the increasing demand for biofuel energy. A watershed level scenario analysis is often applied to figure out a sustainable way to strike the balance between food and fuel demands, and maintain environment integrity. However, a solid modeling application requires a clear understanding of crop responses under various climate stresses. This …

Lepton Pair Čerenkov Radiation Emitted By Tachyonic Neutrinos: Lorentz-Covariant Approach And Icecube Data, Ulrich D. Jentschura, Robert B. Ehrlich

Physics Faculty Research & Creative Works

Current experiments do not exclude the possibility that one or more neutrinos are very slightly superluminal or that they have a very small tachyonic mass. Important bounds on the size of a hypothetical tachyonic neutrino mass term are set by lepton pair Čerenkov radiation (LPCR), that is, by the decay channel → e⁺ e^- , which proceeds via a virtual Z⁰ boson. Here, we use a Lorentz-invariant dispersion relation which leads to very tight constraints on the tachyonic mass of neutrinos; we also calculate decay and energy loss rates. A possible cutoff seen in the IceCube neutrino …

Extracting Conformational Structure Information Of Benzene Molecules Via Laser-Induced Electron Diffraction, Yuta Ito, Chuncheng Wang, Anh-Thu Le, Misaki Okunishi, Dajun Ding, C. D. Lin, Kiyoshi Ueda

Physics Faculty Research & Creative Works

We have measured the angular distributions of high energy photoelectrons of benzene molecules generated by intense infrared femtosecond laser pulses. These electrons arise from the elastic collisions between the benzene ions with the previously tunnel-ionized electrons that have been driven back by the laser field. Theory shows that laser-free elastic differential cross sections (DCSs) can be extracted from these photoelectrons, and the DCS can be used to retrieve the bond lengths of gas-phase molecules similar to the conventional electron diffraction method. From our experimental results, we have obtained the C-C and C-H bond lengths of benzene with a spatial resolution …

Wormhole Geometries In Fourth-Order Conformal Weyl Gravity, Gabriele U. Varieschi, Kellie L. Ault

Physics Faculty Works

We present an analysis of the classic wormhole geometries based on conformal Weyl gravity, rather than standard general relativity. The main characteristics of the resulting traversable wormholes remain the same as in the seminal study by Morris and Thorne, namely, that effective super-luminal motion is a viable consequence of the metric. Improving on previous work on the subject, we show that for particular choices of the shape and redshift functions the wormhole metric in the context of conformal gravity does not violate the main energy conditions at or near the wormhole throat. Some exotic matter might still be needed at …

Schwarzschild Spacetime And Friedmann-Lemaitre-Robertson-Walker Cosmology, Zachary Cohen

Honors Scholar Theses

The advent of General Relativity via Einstein's field equations revolutionized our understanding of gravity in our solar system and universe. The idea of General Relativity posits that gravity is entirely due to the geometry of the universe -- that is, the mass distribution throughout the universe results in the ``curving" of spacetime, which gives us the physics we see on a large scale. In the framework of General Relativity, we find that the universe behaves differently than was predicted in the model of gravitation developed by Newton. We will derive the general relativistic model for a simple system near a …

Cybersecurity Best Practices For Information Professionals, Darla Jackson

Other Faculty Publications

No abstract provided.