Physical Sciences and Mathematics Commons^™

Lagrangian Relaxation For Large-Scale Multi-Agent Planning, Geoff Gordon, Pradeep Varakantham, William Yeoh, Hoong Chuin Lau, Shih-Fen Cheng

Research Collection School Of Computing and Information Systems

Multi-agent planning is a well-studied problem with various applications including disaster rescue, urban transportation and logistics, both for autonomous agents and for decision support to humans. Due to computational constraints, existing research typically focuses on one of two scenarios: unstructured domains with many agents where we are content with heuristic solutions, or domains with small numbers of agents or special structure where we can provide provably near-optimal solutions. By contrast, in this paper, we focus on providing provably near-optimal solutions for domains with large numbers of agents, by exploiting a common domain-general property: if individual agents each have limited influence …

On Recommending Hashtags In Twitter Networks, Su Mon Kywe, Tuan-Anh Hoang, Ee Peng Lim, Feida Zhu

Research Collection School Of Computing and Information Systems

Twitter network is currently overwhelmed by massive amount of tweets generated by its users. To effectively organize and search tweets, users have to depend on appropriate hashtags inserted into tweets. We begin our research on hashtags by first analyzing a Twitter dataset generated by more than 150,000 Singapore users over a three-month period. Among several interesting findings about hashtag usage by this user community, we have found a consistent and significant use of new hashtags on a daily basis. This suggests that most hashtags have very short life span. We further propose a novel hashtag recommendation method based on collaborative …

Extracting And Normalizing Entity-Actions From Users' Comments, Swapna Gottipati, Jing Jiang

Research Collection School Of Computing and Information Systems

With the growing popularity of opinion-rich resources on the Web, new opportunities and challenges arise and aid people in actively using such information to understand the opinions of others. Opinion mining process currently focuses on extracting the sentiments of the users on products, social, political and economical issues. In many instances, users not only express their sentiments but also contribute their ideas, requests and suggestions through comments. Such comments are useful for domain experts and are referred to as actionable content. Extracting actionable knowledge from online social media has attracted a growing interest from both academia and the industry. We …

Creating The Park Cool Island In An Inner-City Neighborhood: Heat Mitigation Strategy For Phoenix, Az, Juan Declet-Barreto, Anthony J. Brazel, Chris A. Martin, Winston T. L. Chow, Sharon L. Harlan

Research Collection School of Social Sciences

We conducted microclimate simulations in ENVI-Met 3.1 to evaluate the impact of vegetation in lowering temperatures during an extreme heat event in an urban core neighborhood park in Phoenix, Arizona. We predicted air and surface temperatures under two different vegetation regimes: existing conditions representative of Phoenix urban core neighborhoods, and a proposed scenario informed by principles of landscape design and architecture and Urban Heat Island mitigation strategies. We found significant potential air and surface temperature reductions between representative and proposed vegetation scenarios: 1) a Park Cool Island effect that extended to non-vegetated surfaces; 2) a net cooling of air underneath …

Do Hackers Seek Variety? An Empirical Analysis Of Website Defacements, Kok Wei Ooi, Seung-Hyun Kim, Qiu-Hong Wang, Kai Lung Hui

Research Collection School Of Computing and Information Systems

The importance of securing the cyberspace is higher than ever along with the evolution of cyber attacks launched by hackers with malicious intention. However, there has been little research to understand the hackers who are the most important agents determining the landscape of information security. This paper investigates the behaviors of hackers using a longitudinal dataset of defacement attacks. Based on theories of economics of criminal behaviors and variety seeking, we find that hackers seek variety in choosing their victims in terms of region, hacking method, and the type of operating systems; as their prior experience is focused in terms …

Community-Based Classification Of Noun Phrases In Twitter, Freddy Chong Tat Chua, William W. Cohen, Justin Betterridge, Ee-Peng Lim

Research Collection School Of Computing and Information Systems

Many event monitoring systems rely on counting known keywords in streaming text data to detect sudden spikes in frequency. But the dynamic and conversational nature of Twitter makes it hard to select known keywords for monitoring. Here we consider a method of automatically finding noun phrases (NPs) as keywords for event monitoring in Twitter. Finding NPs has two aspects, identifying the boundaries for the subsequence of words which represent the NP, and classifying the NP to a specific broad category such as politics, sports, etc. To classify an NP, we define the feature vector for the NP using not just …

Filesystems: Addressing The Last-Mile “Problem” In Services-Oriented/Cloud Computing, George K. Thiruvathukal, Joseph P. Kaylor, Konstantin Läufer

Computer Science: Faculty Publications and Other Works

We have designed and implemented RestFS, a software framework that provides a uniform, configurable connector layer for mapping remote web-based resources to local filesystem-based resources, recognizing the similarity between these two types of resources. Such mappings enable programmatic access to a resource, as well as composition of two or more resources, through the local operating system’s standard filesystem application programming interface (API), script-able file-based command-line utilities, and interprocess communication (IPC) mechanisms. The framework supports automatic and manual authentication.

As part of this talk, we demonstrate a new filesystem that interfaces to the SketchFab.com service to support 3D model visualization. For …

2000 Year Moisture Source Record From A Central Nevada Speleothem, Paul Pribyl

UNLV Theses, Dissertations, Professional Papers, and Capstones

The goal of this study was to determine the moisture source of winter precipitation in the central Great Basin for the past 2000 years, and to elucidate the role of Pacific Ocean and North American climate variability modes in driving observed droughts of the region around the Medieval Climatic Anomaly (MCA, ~900-1300 CE). Here a high resolution (~2-4 year) precisely dated moisture source reconstruction is presented from the δ18O values of speleothem LC-1 collected from Leviathan Cave in central Nevada, which reveals significant δ18O variability. I attribute the δ18O variability to changes in winter-season moisture circulation over the past 2000 …

A Time Series Analysis Method Using Hidden Variables For Gene Network Reconstruction, Xi Wu

Dissertations

The DNA microarray technology can be applied to obtain time series data which contains thousands of genes and tens of time points. When confront the great amount of data points a fast and effective method must be constructed to extract useful information. The assumption that the interactions between genes are static in the time series data is made. After made the assumption how to reconstruct those interactions becomes a difficulty problem. Since the underlying interactions between genes are complicated, which involve transcription, translation and protein-protein interaction, to construct a model from physicochemistry is almost impossible/effortless. The popular methods constructed from …

Identification Of An Unknown Meteorite Found In North Africa, Carroll C. Rigler

Chancellor’s Honors Program Projects

No abstract provided.

Rapid Knowledge Assessment (Rka): Assessing Students Content Knowledge Through Rapid, In Class Assessment Of Expertise, Erin Margaret O'Connell

Theses and Dissertations

Understanding how students go about problem solving in chemistry lends many possible advantages for interventions in teaching strategies for the college classroom. The work presented here is the development of an in-classroom, real-time, formative instrument to assess student expertise in chemistry with the purpose of developing classroom interventions. The development of appropriate interventions requires the understanding of how students go about starting to solve tasks presented to them, what their mental effort (load on working memory) is, and whether or not their performance was accurate. To measure this, the Rapid Knowledge Assessment (RKA) instrument uses clickers (handheld electronic instruments for …

The Effects Of Replacing Dispersed Trash And Recycling Bins With Integrated Waste Receptacles On The Accuracy Of Waste Sorting In An Academic Building, Katherine J. Binder

Masters Theses

Numerous researchers and theorists have attempted to explain the existence of the gap between the possession of environmental knowledge and awareness and the display of pro-environmental behavior (Glasser, 2007; Kollmuss & Agyeman, 2002). Behavior analysis is uniquely aligned to contribute to this discussion through its emphasis on the role of controlling variables in behavior change. A growing number of behavioral research studies address the challenges of group-contingencies in an effort to solve real-world gaps (Lehman & Geller, 2004). This study was designed as a continuation of the line of behavioral research designed to increase recycling rates and also as an …

Direct Analysis Of Hops By Leaf Spray And Paper Spray Mass Spectrometry, Kari Blain

Masters Theses

The objective of this research is to develop a new and innovative method of hops analysis, which is much faster than standard testing methods, as well as reduce the amount of consumables and solvent used. A detailed discussion on the development of an ambient ionization mass spectrometry method called paper spray (PS-MS) and leaf spray (LS-MS) mass spectrometry will be presented. This research investigates the use of PS-MS and LS-MS techniques to determine the α- and β- acids present in hops. PS-MS and LS-MS provide a fast way to analyze hops samples by delivering data as rapidly as a UV-Vis …

Sediment Metal Concentrations As A Function Of Land Use In The Charles River, Eastern Massachusetts, Darryl L. Luce

Graduate Doctoral Dissertations

Two sediment cores and eleven grab samples collected from the Charles River were analyzed to determine changes to the concentration of metals in sediments due to anthropogenic changes in the watershed. The unique aspect of this research was that sediment cores from the same geologic setting, yet having widely different sources, were compared. The findings from that comparison were used to focus the investigation through the remainder of the Charles River. The radionuclides 210Pb, 214Pb, and 137Cs established the year of deposition in the sediment cores. The concentrations of aluminum (Al), iron (Fe), manganese (Mn), copper (Cu), zinc (Zn), chromium …

Boolean And Profinite Loops, Benjamin Andrew Phillips

Dissertations

A Quasigroup G consists of a set G together with a binary operation ∗ : G × G → G such that, for any elements a, b ∈ G there are unique solutions to the equations a ∗ x = b and y ∗ a = b within G. A loop is a quasigroup which also contains a 2-sided identity element. More heuristically, loops are essentially non-associative groups. However, without an associative binary operation, some of the familiar properties found in groups, such as 2-sided inverse, need not be present in loops.

The study of quasigroups and loops emerges …

Identification And Classification Of Stratospheric Sudden Warming Events, Thomas S. Ehrmann

Doctoral Dissertations and Master's Theses

Analysis of northern hemisphere stratospheric data from 1978-2011 is used to identify and classify Stratospheric Sudden Warming events. A total of 41 events are identified during this 33 year period, resulting in an average occurrence rate of 1.24 events/year. No significant variation in the rate is observed during the period analyzed. The average temperature increase during an SSW event is 12 K and the average duration is 32 days. Each identified event is classified as either a vortex displacement or split event and the ratio of displacement to split events is found to be 0.86.

Math, Minds, Machines, Christopher V. Carlile

Chancellor’s Honors Program Projects

No abstract provided.

The Design And Implementation Of A Mobile Game Engine For The Android Platform, Jon Hammer

Computer Science and Computer Engineering Undergraduate Honors Theses

In this thesis, a two-dimensional game engine is proposed for the Android mobile platform that facilitates rapid development of those games by individual developers or hobbyists. The essential elements of game design are presented so as to introduce the reader to the concepts that are crucial for comprehension of the paper. A brief overview of the Android Operating System is also included for those unfamiliar with it. Three primary design goals are identified, and a prototype solution is described in detail. The prototype is then evaluated against those design goals to see how well it accomplishes each task. The results …

An Efficient Image Segmentation Algorithm Using Bidirectional Mahalanobis Distance, Rahul Suresh

All Theses

In this thesis, we present an efficient graph-based image-segmentation algorithm that improves upon the drawbacks of the minimum spanning tree based segmentation algorithm, namely leaks that occur due to the criterion used to merge regions, and the sensitivity of the output to the parameter k. To address these problems, we propose the use of bidirectional Mahalanobis distance, along with a Gaussian model for each region, and an intuitive normalized parameter τ that replaces k and works for all images without having to be changed. Furthermore, we propose an approximation to the algorithm that enables it to run efficiently in O(NlogN) …

Convex Hull Characterization Of Special Polytopes In N-Ary Variables, Ruobing Shen

All Theses

This paper characterizes the convex hull of the set of n-ary vectors that are lexicographically less than or equal to a given such vector. A polynomial number of facets is shown to be sufficient to describe the convex hull. These facets generalize the family of cover inequalities for the binary case. They allow for advances relative to both the modeling of integer variables using base-n expansions, and the solving of n-ary knapsack problems with weakly super-decreasing coefficients.

Contour Extraction Of Drosophila Embryos Using Active Contours In Scale Space, Soujanya Siddavaram Ananta

Masters Theses & Specialist Projects

Contour extraction of Drosophila embryos is an important step to build a computational system for pattern matching of embryonic images which aids in the discovery of genes. Automatic contour extraction of embryos is challenging due to several image variations such as size, shape, orientation and neigh- boring embryos such as touching and non-touching embryos. In this thesis, we introduce a framework for contour extraction based on the connected components in the gaussian scale space of an embryonic image. The active contour model is applied on the images to refine embryo contours. Data cleaning methods are applied to smooth the jaggy …

Rule-Based Precise Localization Services In Mobile Environments, Mohammed Elbes

Dissertations

In recent years there has been great interest in the positioning of people and assets in indoor and outdoor environments. Many systems were constructed to accomplish this. The application of these systems depends on the environment and the precision required for localization. The Global Positioning System (GPS) cannot be used for a precise indoor localization due to the attenuation and scattering of the signals. For indoor environments, other technologies like Wireless LAN, laser, camera images and motion sensors are used in precise localization. GPS can be used in outdoor environments but if localization accuracy is a critical requirement, other technologies …

Evaluation Of Polymer Gel Dosimeters For Measurements Of Dose And Let In Proton Beams, Kevin M. Vredevoogd

Dissertations & Theses (Open Access)

This project assessed the effectiveness of polymer gel dosimeters as tools for measuring the dose deposited by and LET of a proton beam. A total of three BANG® dosimeter formulations were evaluated: BANG®-3-Pro-2 BANGkits™ for dose measurement and two BANG®-3 variants, the LET-Baseline and LET-Meter dosimeters, for LET measurement. All dosimeters were read out using an OCT scanner. The basic characteristics of the BANGkits™ were assessed in a series of photon and electron irradiations. The dose-response relationship was found to be sigmoidal with a threshold for response of approximately 15 cGy. The active region of the dosimeter, the volume in …

Impact Of Large Mammal Herbivory On The Federally Threatened Plant, Scutellaria Montana Chapm (Large-Flowered Skullcap) At A Millitary Training Site, Catoosa County, Georgia, Andrea Renee Benson

Masters Theses and Doctoral Dissertations

Scutellaria montana Chapm. (Large-flowered skullcap) is a federally listed species endemic to a few counties in northwestern Georgia and southeastern Tennessee. A large population of this species is housed within the Tennessee Army National Guard Volunteer Training Site (VTS) in Catoosa County, GA. To investigate the impacts of large mammal herbivores on this species at the VTS, an exclosure experiment was conducted in the field during 2011 and 2012. Results indicate that deer are not negatively impacting S. montana at the individual or population levels, but and after the second season, it was apparent that the white PVC pipe used …

Exploration Of The Effectiveness Of Apple Ios Devices And Bluetooth Low-Energy Nodes In The Evaulation Of Stroke Patient Rehabilitation And Recovery, Robert Derveloy

Masters Theses and Doctoral Dissertations

The goal of this study is to help establish a foundation for cost effective stroke patient telerehabilitation by examining the efficacy of off-the-shelf consumer motion sensors. This paper examines the practical implications of utilizing Apple iOS mobile devices and Variable Technology KORE NODE devices in the evaluation of stroke patient recovery. Several algorithms are proposed to handle the user positioning and cheating detection requirements of the Functional Reach Test (FRT), efficient scoring of the National Institutes of Health Stroke Scale (NIHSS) motor arm exams, and real-time fall detection monitoring.

Structure And Chemistry Of Model Catalysts In Ultrahigh Vacuum, Joshua D. Walker

Theses and Dissertations

The study of catalysis is a key area of focus not only in the industrial sector but also in the nature and biological systems. The market for catalysis is a multi-billion dollar industry. Many of the materials and products we use on a daily basis are formed through a catalytic process. The quest to understanding and improving catalytic mechanisms is ongoing. Many model catalysts use transition metals as a support for chemical reactions to take place due to their selectivity and activity. Palladium, gold, and copper metals are studied in this work and show the ability to be catalytically reactive. …

High-Order-Harmonic-Generation Spectroscopy With An Elliptically Polarized Laser Field, M. V. Frolov, N. L. Manakov, T. S. Sarantseva, Anthony F. Starace

Anthony F. Starace Publications

Analytic formulas describing high-order-harmonic generation (HHG) by atoms in an intense laser field with small ellipticity are obtained quantum mechanically in the tunneling limit. The results show that factorization of the HHG yield in terms of an electron wave packet and the photorecombination cross section (PRCS) is valid only for s states of a bound atomic electron, whereas the HHG yield for p states involves two different atomic parameters. For the latter case, elliptic HHG spectroscopy enables one to retrieve both the energy and angular dependence of the PRCS of the target atom, as we illustrate for the case of …

Aspects Of General Relativity In 1+1 Dimensions, Richard D. Mellinger Jr

Physics

What would be the properties of a universe with only one spatial dimension and one time dimension? General relativity in 1+1 dimensions is unique since the two curvature terms in the Einstein field equations cancel. This makes the Einstein field equations algebraic rather than differential equations. This special feature can make 1+1 dimensionality attractive as an instructional tool to simplify the mathematics that many beginners find opaque. We explore the implications and features of the Einstein field equations in 1+1 dimensions and find they provide a surprisingly rich and interesting model. We then study an alternate theory and its implications …

Building An Alpha Spectrometer For The Cuore Collaboration, David J. Miller

Physics

This paper will give the reader a brief introduction to the Standard Model, Neutrinoless Double Beta Decay (0νββ), and the CUORE experiment under construction at Gran Sasso National Lab in Assergi, Italy. The remainder of the paper will describe the process of creating a working alpha spectrometry system using silicon detectors and NIM and CAMAC electronics. Extensive details of the troubleshooting and calibration period are presented as a way for the reader to better understand the concepts involved in alpha spectroscopy and to not repeat mistakes made in this development process.

Investigation Of Optical Dipole Traps For Trapping Neutral Atoms For Quantum Computing, Danielle May

Physics

No abstract provided.