Physical Sciences and Mathematics Commons^™

Assess The Interplay Effect Based On The Cyclotron Accelerator Proton Therapy System Machine-Specific Delivery Sequence Model, Lewei Zhao, Gang Liu, J Shen, A Lee, Di Yan, Rohan Deraniyagala, Craig Stevens, Weili Zheng, Xiaoqiang Li, S Tang, Xuanfeng Ding

Conference Presentation Abstracts

No abstract provided.

Diving Below The Spin-Down Limit: Constraints On Gravitational Waves From The Energetic Young Pulsar Psr J0537-6910, Ligo Scientific Collaboration, Virgo Collaboration, Kagra Collaboration, Tiffany Z. Summerscales

Faculty Publications

We present a search for quasi-monochromatic gravitational-wave signals from the young, energetic X-ray pulsar PSR J0537−6910 using data from the second and third observing runs of LIGO and Virgo. The search is enabled by a contemporaneous timing ephemeris obtained using Neutron star Interior Composition Explorer (NICER) data. The NICER ephemeris has also been extended through 2020 October and includes three new glitches. PSR J0537−6910 has the largest spin-down luminosity of any pulsar and exhibits fRequent and strong glitches. Analyses of its long-term and interglitch braking indices provide intriguing evidence that its spin-down energy budget may include gravitational-wave emission from a …

Skyrmions And Biskyrmions In Magnetic Films, Daniel Capic

Dissertations, Theses, and Capstone Projects

Skyrmions have garnered significant attention in condensed matter systems in recent years. In principle, they are topologically protected, so there is a large energy barrier preventing their annihilation. Furthermore, they can exist at the nanoscale, be manipulated with very small currents, and be created by a number of different methods. This makes them attractive for use in potential computing applications. This work studies ferromagnetic skyrmions. In particular, it highlights our small contributions to the field of skyrmions in condensed matter systems, specifically in thin-film ferromagnets.

Rapid Production And Purification Of Dye-Loaded Liposomes By Electrodialysis-Driven Depletion, Gamid Abatchev, Andrew Bogard, Zoe Hutchinson, Jason Ward, Daniel Fologea

Physics Faculty Publications and Presentations

Liposomes are spherical-shaped vesicles that enclose an aqueous milieu surrounded by bilayer or multilayer membranes formed by self-assembly of lipid molecules. They are intensively exploited as either model membranes for fundamental studies or as vehicles for delivery of active substances in vivo and in vitro. Irrespective of the method adopted for production of loaded liposomes, obtaining the final purified product is often achieved by employing multiple, time consuming steps. To alleviate this problem, we propose a simplified approach for concomitant production and purification of loaded liposomes by exploiting the Electrodialysis-Driven Depletion of charged molecules from solutions. Our investigations show that …

Arsenic In Petroleum-Contaminated Groundwater Near Bemidji, Minnesota Is Predicted To Persist For Centuries, Brady A. Ziegler, G. H. Crystal Ng, I. M. Cozzarelli, A. J. Dunshee, M. E. Schreiber

Geosciences Faculty Research

We used a reactive transport model to investigate the cycling of geogenic arsenic (As) in a petroleum-contaminated aquifer. We simulated As mobilization and sequestration using surface complexation reactions with Fe(OH)₃ during petroleum biodegradation coupled with Fe-reduction. Model results predict that dissolved As in the plume will exceed the U.S. and EU 10 µg/L drinking water standard for ~400 years. Non-volatile dissolved organic carbon (NVDOC) in the model promotes As mobilization by exerting oxygen demand, which maintains anoxic conditions in the aquifer. After NVDOC degrades, As re-associates with Fe(OH)₃ as oxygenated conditions are reestablished. Over the 400-year simulation, As …

Gwtc-2: Compact Binary Coalescences Observed By Ligo And Virgo During The First Half Of The Third Observing Run, R. Abbott, T. D. Abbott, S. Abraham, F. Acernese, K. Ackley, A. Adams, C. Adams, R. X. Adhikari, V. B. Adya, C. Affeldt, M. Agathos, K. Agatsuma, N. Aggarwal, O. D. Aguiar, L. Aiello, A. Ain, P. Ajith, S. Akcay, G. Allen, Tiffany Z. Summerscales

Faculty Publications

We report on gravitational-wave discoveries from compact binary coalescences detected by Advanced LIGO and Advanced Virgo in the first half of the third observing run (O3a) between 1 April 2019 15:00 UTC and 1 October 2019 15:00 UTC. By imposing a false-alarm-rate threshold of two per year in each of the four search pipelines that constitute our search, we present 39 candidate gravitational-wave events. At this threshold, we expect a contamination fraction of less than 10%. Of these, 26 candidate events were reported previously in near-real time through gamma-ray coordinates network notices and circulars; 13 are reported here for the …

Teleseismic P-Wave Attenuation Beneath The Southeastern United States, Ashutosh Shrivastava, Kelly H. Liu, Stephen S. Gao

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Seismic attenuation is an important parameter for characterizing subsurface morphology and thermal structure. In this study, we use P-wave amplitude spectra from 588 teleseismic events recorded by 477 broadband seismic stations in the southeastern United States to examine the spatial variations of seismic attenuation in the crust and upper mantle. The resulting seismic attenuation parameter (∆t*) measurements obtained using the spectral ratio technique reveal a zone of relatively low attenuation in the Gulf of Mexico Coastal Plain and the southwestern terminus of the Piedmont province. Spatial coherency analysis of the ∆t* observations suggests that the center of the low attenuation …

Computational Analysis Of Protein Stability And Allosteric Interaction Networks In Distinct Conformational Forms Of The Sars Cov 2 Spike D614g Mutant: Reconciling Functional Mechanisms Through Allosteric Model Of Spike Regulation, Gennady M. Verkhivker, Steve Agajanian, Deniz Oztas, Grace Gupta

Mathematics, Physics, and Computer Science Faculty Articles and Research

In this study, we used an integrative computational approach to examine molecular mechanisms underlying functional effects of the D614G mutation by exploring atomistic modeling of the SARS-CoV-2 spike proteins as allosteric regulatory machines. We combined coarse-grained simulations, protein stability and dynamic fluctuation communication analysis with network-based community analysis to examine structures of the native and mutant SARS-CoV-2 spike proteins in different functional states. Through distance fluctuations communication analysis, we probed stability and allosteric communication propensities of protein residues in the native and mutant SARS-CoV-2 spike proteins, providing evidence that the D614G mutation can enhance long-range signaling of the allosteric spike …

Agent-Based Semantic Role Mining For Intelligent Access Control In Multi-Domain Collaborative Applications Of Smart Cities, Rubina Ghazal, Ahmad Kamran Malik, Basit Raza, Nauman Qadeer, Nafees Qamar, Sajal Bhatia

School of Computer Science & Engineering Faculty Publications

Significance and popularity of Role-Based Access Control (RBAC) is inevitable; however, its application is highly challenging in multi-domain collaborative smart city environments. The reason is its limitations in adapting the dynamically changing information of users, tasks, access policies and resources in such applications. It also does not incorporate semantically meaningful business roles, which could have a diverse impact upon access decisions in such multi-domain collaborative business environments. We propose an Intelligent Role-based Access Control (I-RBAC) model that uses intelligent software agents for achieving intelligent access control in such highly dynamic multi-domain environments. The novelty of this model lies in using …

Diving Below The Spin-Down Limit: Constraints On Gravitational Waves From The Energetic Young Pulsar Psr J0537-6910, R. Abbott, T. D. Abbott, S. Abraham, F. Acernese, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Karla E. Ramirez, W. H. Wang

Physics and Astronomy Faculty Publications and Presentations

We present a search for quasi-monochromatic gravitational-wave signals from the young, energetic X-ray pulsar PSR J0537-6910 using data from the second and third observing runs of LIGO and Virgo. The search is enabled by a contemporaneous timing ephemeris obtained using Neutron star Interior Composition Explorer (NICER) data. The NICER ephemeris has also been extended through 2020 October and includes three new glitches. PSR J0537-6910 has the largest spin-down luminosity of any pulsar and exhibits fRequent and strong glitches. Analyses of its long-term and interglitch braking indices provide intriguing evidence that its spin-down energy budget may include gravitational-wave emission from a …

Approaching The Motional Ground State Of A 10-Kg Object, Chris Whittle, E. D. Hall, S. E. Dwyer, N. Mavalvala, Vivishek Sudhir, R. Abbott, A. Ananyeva, C. Austin, L. Barsotti, Karla E. Ramirez

Physics and Astronomy Faculty Publications and Presentations

The motion of a mechanical object— even a human-sized object— should be governed by the rules of quantum mechanics. Coaxing them into a quantum state is, however, difficult: the thermal environment effectively masks any quantum signature of the object’s motion. Indeed, it also masks effects of proposed modifications of quantum mechanics at large mass scales. We prepare the center-of-mass motion of a 10 kg mechanical oscillator in a state with an average phonon occupation of 10.8. The reduction in oscillator temperature, from room temperature to 77 nK, represents a 100-fold improvement in the reduction of temperature of a solid-state mechanical …

Sequence-To-Sequence Learning For Automated Software Artifact Generation, Zhongxin Liu, Xin Xia, David Lo

Research Collection School Of Computing and Information Systems

During the development and maintenance of a software system, developers produce many digital artifacts besides source code, e.g., requirement documents, code comments, change history, bug reports, etc. Such artifacts are valuable for developers to understand and maintain the software system. However, creating software artifacts can be burdensome and developers sometimes neglect to write and maintain important artifacts. This problem can be alleviated by software artifact generation tools, which can assist developers in creating software artifacts and automatically generate artifacts to replace existing empty ones. The focus of this chapter is automated software artifact generation (hereon, SAG) using seq2seq learning. This …

Minimizing The Regret Of An Influence Provider, Yipeng Zhang, Yuchen Li, Zhifeng Bao, Baihua Zheng

Research Collection School Of Computing and Information Systems

Influence maximization has been studied extensively from the perspective of the influencer. However, the influencer typically purchases influence from a provider, for example in the form of purchased advertising. In this paper, we study the problem from the perspective of the influence provider. Specifically, we focus on influence providers who sell Out-of-Home (OOH) advertising on billboards. Given a set of requests from influencers, how should an influence provider allocate resources to minimize regret, whether due to forgone revenue from influencers whose needs were not met or due to over-provisioning of resources to meet the needs of influencers? We formalize this …

Multi-View Collaborative Network Embedding, Sezin Kircali Ata, Yuan Fang, Min Wu, Jiaqi Shi, Chee Keong Kwoh, Xiaoli Li

Research Collection School Of Computing and Information Systems

Real-world networks often exist with multiple views, where each view describes one type of interaction among a common set of nodes. For example, on a video-sharing network, while two user nodes are linked, if they have common favorite videos in one view, then they can also be linked in another view if they share common subscribers. Unlike traditional single-view networks, multiple views maintain different semantics to complement each other. In this article, we propose Multi-view collAborative Network Embedding (MANE), a multi-view network embedding approach to learn low-dimensional representations. Similar to existing studies, MANE hinges on diversity and collaboration—while diversity enables …

Hierarchical Reinforcement Learning: A Comprehensive Survey, Shubham Pateria, Budhitama Subagdja, Ah-Hwee Tan, Chai Quek

Research Collection School Of Computing and Information Systems

Hierarchical Reinforcement Learning (HRL) enables autonomous decomposition of challenging long-horizon decision-making tasks into simpler subtasks. During the past years, the landscape of HRL research has grown profoundly, resulting in copious approaches. A comprehensive overview of this vast landscape is necessary to study HRL in an organized manner. We provide a survey of the diverse HRL approaches concerning the challenges of learning hierarchical policies, subtask discovery, transfer learning, and multi-agent learning using HRL. The survey is presented according to a novel taxonomy of the approaches. Based on the survey, a set of important open problems is proposed to motivate the future …

Requirements Metrics - A Working List, William L. Honig

Computer Science: Faculty Publications and Other Works

A working set of metrics for review of requirements materials including documents.

Establishing Suitable Metrics To Encourage Broader Use Of Atomic Requirements, William L. Honig

Computer Science: Faculty Publications and Other Works

Despite the apparent benefits of singular, individual, or atomic requirements, their use remains limited, and teaching their creation is difficult. The acceptance of a set of requirements metrics specifically designed to evaluate atomic requirements may lead to their better utilization and improved requirements engineering. Twelve metrics designed to measure atomic requirements are presented here: six used on individual requirements statements and six applied to a requirements document or set of requirement statements. Example metrics for individual requirements are Requirement Completeness and Requirement Atomicity; examples to measure multiple requirements include Requirements Traceablity and Requirements Purity. These metrics are designed to work …

Advancing The Ability To Predict Cognitive Decline And Alzheimer’S Disease Based On Genetic Variants Beyond Amyloid-Beta And Tau, Naveen Rawat

Master's Projects

A growing amount of neurodegenerative R&D is focused on identifying genomic- based explanations of AD that are beyond Amyloid-b and Tau. The proposed effort involves identifying some of the genomic variations, such as single nucleotide polymorphisms (SNPs), allele , chromosome, epigenetic contributors to MCI and AD that are beyond Aβ and Tau.

The project involves building a prediction model based on a support vector machine (SVM) classifier that takes into account the genomic variations and epigenetic factors to predict the early stage of mild cognitive impairment (MCI) and Alzheimer disease (AD). To achieve this, picking up important feature sets which …

Witness For Two-Site Enabled Coordination, Sriram Priyatham Siram

Master's Projects

Many replicated data services utilize majority quorums to safely replicate data changes in the presence of server failures. Majority quorum-based services require a simple majority of the servers to be operational for the service to stay available. A key limitation of the majority quorum is that if a service is composed of just two servers, progress cannot be made even if a single server fails because the majority quorum size is also two. This is called the Two-Server problem. A problem similar to the Two-Server problem occurs when a service’s servers are spread across only two failure domains. Servers in …

Iowa Waste Reduction Center Newsletter, June 2021, University Of Northern Iowa. Iowa Waste Reduction Center.

Iowa Waste Reduction Center Newsletter

Inside this Issue:

--- A Nearby Disaster
--- IWRC Updated Paint Tracker Program
--- IWRC's Newest Addition, UNI Associate Professor of Economics, Alicia Rosburg (P.h.D.)
--- Brandon Stenger is Welcomed to the IWRC Team!
--- Industry News

On Predicting Personal Values Of Social Media Users Using Community-Specific Language Features And Personal Value Correlation, Amila Silva, Pei Chi Lo, Ee-Peng Lim

Research Collection School Of Computing and Information Systems

Personal values have significant influence on individuals’ behaviors, preferences, and decision making. It is therefore not a surprise that personal values of a person could influence his or her social media content and activities. Instead of getting users to complete personal value questionnaire, researchers have looked into a non-intrusive and highly scalable approach to predict personal values using user-generated social media data. Nevertheless, geographical differences in word usage and profile information are issues to be addressed when designing such prediction models. In this work, we focus on analyzing Singapore users’ personal values, and developing effective models to predict their personal …

Knowledge And Anxiety About Covid-19 In The State Of Qatar, And The Middle East And North Africa Region—A Cross Sectional Study, Sathyanarayanan Doraiswamy, Sohaila Cheema, Maisonneuve Patrick, Amit Abraham, Ingmar Weber, Jisun An, Albert B. Lowenfels, Ravinder Mamtani

Research Collection School Of Computing and Information Systems

While the coronavirus disease 2019 (COVID-19) pandemic wreaked havoc across the globe, we have witnessed substantial mis- and disinformation regarding various aspects of the disease. We conducted a cross-sectional study using a self-administered questionnaire for the general public (recruited via social media) and healthcare workers (recruited via email) from the State of Qatar, and the Middle East and North Africa region to understand the knowledge of and anxiety levels around COVID-19 (April–June 2020) during the early stage of the pandemic. The final dataset used for the analysis comprised of 1658 questionnaires (53.0% of 3129 received questionnaires; 1337 [80.6%] from the …

Sql-Like Interpretable Interactive Video Search, Jiaxin Wu, Phuong Anh Nguyen, Zhixin Ma, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

Concept-free search, which embeds text and video signals in a joint space for retrieval, appears to be a new state-of-the-art. However, this new search paradigm suffers from two limitations. First, the search result is unpredictable and not interpretable. Second, the embedded features are in high-dimensional space hindering real-time indexing and search. In this paper, we present a new implementation of the Vireo video search system (Vireo-VSS), which employs a dual-task model to index each video segment with an embedding feature in a low dimension and a concept list for retrieval. The concept list serves as a reference to interpret its …

Photosensitization And Analytical Study On Reactive Oxygen Intermediates: Self-Sorting Surface Radicals And “On-Off” Sensitizer Function Mechanisms, Sarah J. Belh

Dissertations, Theses, and Capstone Projects

This thesis consists of four chapters which are detailed below. Chapter 1 is an introductory chapter, which lays out the background and purpose of the research.

Chapter 2 describes a study of the mobility of alkoxy radicals on a surface by detection of their recombination product. A novel method called symmetrical product recombination (SRP) utilizes an unsymmetrical peroxide that upon sensitized homolysis recombines to a symmetrical product [R'OOR → R'O•↑ + •OR → ROOR]. This allows for self-sorting of the radical to enhance the recombination path to a symmetrical product, which has been used to deduce surface migratory aptitude. SPR …

Metareasoning, Opportunistic Exploration, And Explanations For Autonomous Indoor Navigation, Raj Korpan

Dissertations, Theses, and Capstone Projects

Autonomous indoor navigation is an important task for mobile robots deployed without a map in real-world environments, such as museums or offices. While it travels, an autonomous robot navigator must contend with lack of prior knowledge, sensor noise, actuator error, and inquisitive people. This dissertation addresses these challenges with a cognitively-based hierarchical reasoning architecture that incorporates learning, exploration, reactivity, planning, heuristics, and explanations. Evaluation by simulation in large, complex, indoor environments shows that a robot controller can successfully navigate without a detailed map of every obstruction's location when it performs limited initial global exploration and plans in its learned spatial …

Quantization Coefficients For Uniform Distributions On The Boundaries Of Regular Polygons, Joel Hansen, Itzamar Marquez, Mrinal Kanti Roychowdhury, Eduardo Torres

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

In this paper, we give a general formula to determine the quantization coefficients for uniform distributions defined on the boundaries of different regular m-sided polygons inscribed in a circle. The result shows that the quantization coefficient for the uniform distribution on the boundary of a regular m-sided polygon inscribed in a circle is an increasing function of m, and approaches to the quantization coefficient for the uniform distribution on the circle as m tends to infinity.

Hexagon Tilings Of The Plane That Are Not Edge-To-Edge, Dirk Frettlöh, Alexey Glazyrin, Z. Lángi

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

An irregular vertex in a tiling by polygons is a vertex of one tile and belongs to the interior of an edge of another tile. In this paper we show that for any integer k≥3, there exists a normal tiling of the Euclidean plane by convex hexagons of unit area with exactly k irregular vertices. Using the same approach we show that there are normal edge-to-edge tilings of the plane by hexagons of unit area and exactly k many n-gons (n>6) of unit area. A result of Akopyan yields an upper bound for k depending on the maximal diameter …

Check Your Tech, Whose Responsibility Is It When Cyberharassment Occurs?, Dympna O'Sullivan, Damian Gordon, Michael Collins, Emma Murphy

Conference papers

Social media has become a dominant aspect of many people’s lives in many countries. Unfortunately that resulted in widespread issues of bullying and harassment. While frequently this harrassment is intentional, there have been occasions where automated processes have been inadvertently responsible for this sort of harassment. The software tools that allow people to harass others could have further features added to them to reduce the amount of harassment that occurs, but more often than not, where programmers are developing these systems then don’t anticipate the range of ways that these technologies will be used (this is called “consequence scanning”). The …

Measurement Of Branching Fractions And Cp Asymmetries For Ds+ →K+ (Η,Π0) And Ds+ →Π+ (Η,Π0) Decays At Belle, Y. Guan, A. J. Schwartz, K. Kinoshita, I. Adachi, H. Aihara, S. Al Said, D. M. Asner, H. Atmacan, V. Aulchenko, T. Aushev, R. Ayad, V. Babu, P. Behera, J. Bennett, M. Bessner, V. Bhardwaj, B. Bhuyan, T. Bilka, J. Biswal

Faculty and Student Publications

We report measurements of the branching fractions and CP asymmetries for Ds+→K+η, Ds+→K+π0, and Ds+→π+η decays, and the branching fraction for Ds+→π+π0. Our results are based on a data sample corresponding to an integrated luminosity of 921 fb-1 collected by the Belle detector at the KEKB e+e- asymmetric-energy collider. Our measurements of CP asymmetries in these decays are the most precise to date; no evidence for CP violation is found.

Engage!: Co-Designing Search Engine Result Pages To Foster Interactions, Garrett Allen, Ben Peterson, Dhanush Kumar Ratakonda, Mostofa Najmus Sakib, Jerry Alan Fails, Casey Kennington, Katherine Landau Wright, Maria Soledad Pera

Computer Science Faculty Publications and Presentations

In this paper, we take a step towards understanding how to design search engine results pages (SERP) that encourage children’s engagement as they seek for online resources. For this, we conducted a participatory design session to enable us to elicit children’s preferences and determine what children (ages 6–12) find lacking in more traditional SERP. We learned that children want more dynamic means of navigating results and additional ways to interact with results via icons. We use these findings to inform the design of a new SERP interface, which we denoted CHIRP. To gauge the type of engagement that a SERP …