Physical Sciences and Mathematics Commons^™

User Identification And Authentication Using Multi-Modal Behavioral Biometrics, Kyle O. Bailey, James S. Okolica, Gilbert L. Peterson

Faculty Publications

Biometric computer authentication has an advantage over password and access card authentication in that it is based on something you are, which is not easily copied or stolen. One way of performing biometric computer authentication is to use behavioral tendencies associated with how a user interacts with the computer. However, behavioral biometric authentication accuracy rates are worse than more traditional authentication methods. This article presents a behavioral biometric system that fuses user data from keyboard, mouse, and Graphical User Interface (GUI) interactions. Combining the modalities results in a more accurate authentication decision based on a broader view of the user's …

Copper Doping Of Zno Crystals By Transmutation Of 64Zn To 65Cu: An Electron Paramagnetic Resonance And Gamma Spectroscopy Study, Matthew C. Recker, John W. Mcclory, Maurio S. Holston [*], Eric M. Golden [*], Nancy C. Giles, Larry E. Halliburton

Faculty Publications

Transmutation of ⁶⁴Zn to ⁶⁵Cu has been observed in a ZnO crystal irradiated with neutrons. The crystal was characterized with electron paramagnetic resonance (EPR) before and after the irradiation and with gamma spectroscopy after the irradiation. Major features in the gamma spectrum of the neutron-irradiated crystal included the primary 1115.5 keV gamma ray from the ⁶⁵Zn decay and the positron annihilation peak at 511 keV. Their presence confirmed the successful transmutation of ⁶⁴Zn nuclei to ⁶⁵Cu. Additional direct evidence for transmutation was obtained from the EPR of Cu²⁺ ions (where ⁶³Cu and ^{65 …}

Binding Of Solvated Peptide (Eplqlkm) With A Graphene Sheet Via Simulated Coarse-Grained Approach, Somayyeh Sheikholeslami, R. B. Pandey, Nadiya Dragneva, Wely Floriano, Oleg Rubel, Stephen A. Barr, Zhifeng Kuang, Rajiv Berry, Rajesh Naik, Barry Farmer

Faculty Publications

Binding of a solvated peptide A1 (¹E ²P ³L ⁴Q ⁵L ⁶K ⁷M) with a graphene sheet is studied by a coarse-grained computer simulation involving input from three independent simulated interaction potentials in hierarchy. A number of local and global physical quantities such as energy, mobility, and binding profiles and radius of gyration of peptides are examined as a function of temperature (T). Quantitative differences (e.g., the extent of binding within a temperature range) and qualitative similarities are observed in results from three simulated potentials. Differences in variations of both local and …

Absence Of Long-Wavelength Cerenkov Radiation With Isotropic Lorentz And Cpt Violation, Brett David Altschul

Faculty Publications

Modified theories of electrodynamics that include violations of Lorentz symmetry often allow for the possibility of vacuum Cerenkov radiation. This phenomenon has previously been studied in a number of Lorentz-violating theories, but none of the methods that have previously been developed are sufficient to study a theory with a timelike Chern-Simons term k_AF, because such a term may generate exponentially growing solutions to the field equations. Searching for vacuum Cerenkov radiation in a theory with a purely timelike Chern-Simons term using only elementary methods, we find that, despite the presence of the runaway modes, a charge in uniform …

Implications Of The Landauer Limit For Quantum Logic, F. Matthew Mihelic

Faculty Publications

The design of any system of quantum logic must take into account the implications of the Landauer limit for logical bits. Useful computation implies a deterministic outcome, and so any system of quantum computation must produce a final deterministic outcome, which in a quantum computer requires a quantum decision that produces a deterministic qubit. All information is physical, and any bit of information can be considered to exist in a physicality represented as a decision between the two wells of a double well potential in which the energy barrier between the two wells must be greater than kT·ln2. Any proposed …

A Note On Independent Sets In Graphs With Large Minimum Degree And Small Cliques, Jeremy Lyle

Faculty Publications

Graphs with large minimum degree containing no copy of a clique on r vertices (K_r) must contain relatively large independent sets. A classical result of Andrásfai, Erdös, and Sós implies that K_r-free graphs G with degree larger than ((3r − 7)/(3r − 4))|V(G)| must be (r − 1)-partite. An obvious consequence of this result is that the same degree threshold implies an independent set of order (1/(r − 1))|V(G)|. The following paper provides improved bounds on the minimum degree which would imply the …

The Real-Time Instructor Observing Tool For Future Teachers, Cassandra Paul

Faculty Publications

Current educational research shows that students achieve higher learning gains in science classrooms when interactive techniques are used. As a result, we are seeing more high schools and institutions of higher education adopt interactive courses. Unfortunately, it's difficult for future teachers to envision interactive science courses because their experience as students has been dominated by traditional lecture. New educators need to know what interactive science classrooms look like, so that they can model this experience in their own classrooms. The Real-time Instructor Observing Tool (RIOT), a computer application that allows an observer to quickly categorize classroom interactions, can help with …

Search For Gravitational Wave Ringdowns From Perturbed Intermediate Mass Black Holes In Ligo-Virgo Data From 2005-2010, Tiffany Summerscales, The Ligo Scientific Collaboration And The Virgo Collaboration

Faculty Publications

We report results from a search for gravitational waves produced by perturbed intermediate mass black holes (IMBH) in data collected by LIGO and Virgo between 2005 and 2010. The search was sensitive to astrophysical sources that produced damped sinusoid gravitational wave signals, also known as ringdowns, with frequency 50≤f0/Hz≤2000 and decay timescale 0.0001≲τ/s≲0.1 characteristic of those produced in mergers of IMBH pairs. No significant gravitational wave candidate was detected. We report upper limits on the astrophysical coalescence rates of IMBHs with total binary mass 50≤M/M⊙≤450 and component mass ratios of either 1:1 or 4:1. For systems with total mass 100≤M/M⊙≤150, …

Multi-Objective Optimization Of Dead-Reckoning Error Thresholds For Virtual Environments, Jeremy R. Millar, Douglas D. Hodson, Gary B. Lamont, Gilbert L. Peterson

Faculty Publications

Design trade-offs between state consistency and system response time are commonplace in virtual environments. Systems typically rely on predictive consistency algorithms such as dead-reckoning to control consistency and response time. Dead-reckoning error threshold selection determines the consistency/response time trade-off. We extend this trade-off space to explicitly account for the concept of system fairness. We derive a multi-objective optimization problem and apply multi-objective evolutionary algorithms to solve for Pareto optimal error thresholds. Abstract ©2014 IEEE.

Three-Point Current Correlation Functions As Probes Of Effective Conformal Theories, Kassahun Betre

Faculty Publications

See abstract in PDF.

Constraints On Cosmic Strings From The Ligo-Virgo Gravitational Wave Detectors, Tiffany Summerscales, Ligo Scientific Collaboration And Virgo Collaboration

Faculty Publications

Cosmic strings can give rise to a large variety of interesting astrophysical phenomena. Among them, powerful bursts of gravitational waves (GWs) produced by cusps are a promising observational signature. In this Letter we present a search for GWs from cosmic string cusps in data collected by the LIGO and Virgo gravitational wave detectors between 2005 and 2010, with over 625 days of live time. We find no evidence of GW signals from cosmic strings. From this result, we derive new constraints on cosmic string parameters, which complement and improve existing limits from previous searches for a stochastic background of GWs …

Gravitational Waves From Known Pulsars: Results From The Initial Detector Era, Tiffany Summerscales, The Ligo Scientific Collaboration And The Virgo Collaboration

Faculty Publications

We present the results of searches for gravitational waves from a large selection of pulsars using data from the most recent science runs (S6, VSR2 and VSR4) of the initial generation of interferometric gravitational wave detectors LIGO (Laser Interferometric Gravitational-wave Observatory) and Virgo. We do not see evidence for gravitational wave emission from any of the targeted sources but produce upper limits on the emission amplitude. We highlight the results from seven young pulsars with large spin-down luminosities. We reach within a factor of five of the canonical spin-down limit for all seven of these, whilst for the Crab and …

A Trust-Aware System For Personalized User Recommendations In Social Networks, Magdalini Eirinaki, Malamati Louta, Iraklis Varlamis

Faculty Publications

Social network analysis has recently gained a lot of interest because of the advent and the increasing popularity of social media, such as blogs, social networking applications, microblogging, or customer review sites. In this environment, trust is becoming an essential quality among user interactions and the recommendation for useful content and trustful users is crucial for all the members of the network. In this paper, we introduce a framework for handling trust in social networks, which is based on a reputation mechanism that captures the implicit and explicit connections between the network members, analyzes the semantics and dynamics of these …

On The Dynamic Coloring Of Cartesian Product Graphs., Saieed Akbari, Maryam Ghanbari, S. Jahanbekam

Faculty Publications

No abstract provided.

A Meta Analysis Of Pancreatic Microarray Datasets Yields New Targets As Cancer Genes And Biomarkers, Nalin C. W. Goonesekere, Xiaosheng Wang, Lindsey Ludwig, Chittibabu Guda

Faculty Publications

The lack of specific symptoms at early tumor stages, together with a high biological aggressiveness of the tumor contribute to the high mortality rate for pancreatic cancer (PC), which has a five year survival rate of less than 5%. Improved screening for earlier diagnosis, through the detection of diagnostic and prognostic biomarkers provides the best hope of increasing the rate of curatively resectable carcinomas. Though many serum markers have been reported to be elevated in patients with PC, so far, most of these markers have not been implemented into clinical routine due to low sensitivity or specificity. In this study, …

Reducing The Size And Number Of Linear Programs In A Dynamic Gröbner Basis Algorithm, Massimo Caboara, John Edward Perry Iii

Faculty Publications

The goal of the Dynamic Buchberger Algorithm is to compute a Gröbner basis quickly by adjusting the term ordering as the computation proceeds. A known problem concerns the size and number of linear progams to be solved when refining the ordering. This paper describes two methods for reducing both their size and number.

Modeling The Thermosphere As A Driven-Dissipative Thermodynamic System, William R. Frey, C. S. Lin, Matthew B. Garvin, Ariel O. Acebal

Faculty Publications

Thermospheric density impacts satellite position and lifetime through atmospheric drag. More accurate specification of thermospheric temperature, a key input to current models such as the High Accuracy Satellite Drag Model, can decrease model density errors. This paper improves the model of Burke et al. (2009) to model thermospheric temperatures using the magnetospheric convective electric field as a driver. In better alignment with Air Force satellite tracking operations, we model the arithmetic mean temperature, T _1/2, defined by the Jacchia (1977) model as the mean of the daytime maximum and nighttime minimum exospheric temperatures occurring in opposite hemispheres at a …

Identification Of Biomarkers That Distinguish Chemical Contaminants Based On Gene Expression Profiles, Xiaomou Wei, Junmei Ai, Youping Deng, Xin Guan, David R. Johnson, Choo Y. Ang, Chaoyang Zhang, Edward J. Perkins

Faculty Publications

Background: High throughput transcriptomics profiles such as those generated using microarrays have been useful in identifying biomarkers for different classification and toxicity prediction purposes. Here, we investigated the use of microarrays to predict chemical toxicants and their possible mechanisms of action.

Results: In this study, in vitro cultures of primary rat hepatocytes were exposed to 105 chemicals and vehicle controls, representing 14 compound classes. We comprehensively compared various normalization of gene expression profiles, feature selection and classification algorithms for the classification of these 105 chemicals into14 compound classes. We found that normalization had little effect on the averaged …

Lorentz Violation In Fermion-Antifermion Decays Of Spinless Particles, Brett David Altschul

Faculty Publications

If Lorentz and CPT violation exist, they could affect the decays of scalar and pseudoscalar particles. For a decay into a fermion and an antifermion (not necessarily of the same mass), both the total decay rate and the outgoing particle distribution may be modified, through interference between the conventional decay mechanism and a separate Lorentz-violating mechanism. The modifications are sensitive to forms of Lorentz violation that are otherwise rather difficult to study, since at tree level they do not affect particle propagation, but only interaction vertices. Using existing experimental data on charged pion decay, it is possible to constrain three …

Quantifying The Impact Of Atmospheric Deposition On The Biogeochemistry Of Fe And Al In The Upper Ocean: A Decade Of Collaboration With The Us Clivar-Co2 Repeat Hydrography Program, Maxime Grand, Clifton Buck, William Landing, Christopher Measures, Mariko Hatta, William Hiscock, Matthew Brown, Joseph Resing

Faculty Publications

The aerosol deposition of continental material and its partial dissolution in the surface ocean exerts an important control on the distribution of iron and other potentially limiting trace metal (TM) micronutrients in the open ocean. This dust deposition has implications for the regulation of global climate through the coupling of biolimiting TM cycles, marine productivity, and the global carbon cycle. Thus, it is important to determine the locations of dust deposition in the open ocean and to quantify the magnitude and subsequent dissolution of the dust. At present, there are too few dust deposition estimates and solubility measurements in the …

Applicability Of Latent Dirichlet Allocation To Multi-Disk Search, George E. Noel, Gilbert L. Peterson

Faculty Publications

Digital forensics practitioners face a continual increase in the volume of data they must analyze, which exacerbates the problem of finding relevant information in a noisy domain. Current technologies make use of keyword based search to isolate relevant documents and minimize false positives with respect to investigative goals. Unfortunately, selecting appropriate keywords is a complex and challenging task. Latent Dirichlet Allocation (LDA) offers a possible way to relax keyword selection by returning topically similar documents. This research compares regular expression search techniques and LDA using the Real Data Corpus (RDC). The RDC, a set of over 2400 disks from real …

Triplet Ground State Of The Neutral Oxygen-Vacancy Donor In Rutile Tio2, A. T. Brant, Eric M. Golden [*], Nancy C. Giles, Shan Yang, M. A. R. Sarker, S. Watauchi, M. Nagao, I. Tanaka, D. A. Tryk, A. Manivannan, Larry E. Halliburton

Faculty Publications

Electron paramagnetic resonance (EPR) is used to investigate the triplet (S = 1) ground state of the neutral oxygen vacancy in bulk rutile TiO₂ crystals. This shallow donor consists of an oxygen vacancy with two nearest-neighbor, exchange-coupled ³⁺ ions located along the [001] direction and equidistant from the vacancy. The spins of the two trapped electrons, one at each ³⁺ ion, align parallel to give the S = 1 state. These neutral oxygen vacancies are formed near 25 K in as-grown oxidized TiO₂ crystals by illuminating with sub-band-gap 442 nm laser light. The angular dependence of the EPR …

Neutral Nitrogen Acceptors In Zno: The 67Zn Hyperfine Interactions, Eric M. Golden [*], S. M. Evans, Larry E. Halliburton, Nancy C. Giles

Faculty Publications

Electron paramagnetic resonance (EPR) is used to characterize the ⁶⁷Zn hyperfine interactions associated with neutral nitrogen acceptors in zinc oxide. Data are obtained from an n-type bulk crystal grown by the seeded chemical vapor transport method. Singly ionized nitrogen acceptors (N⁻) initially present in the crystal are converted to their paramagnetic neutral charge state (N⁰) during exposure at low temperature to 442 or 633 nm laser light. The EPR signals from these N⁰ acceptors are best observed near 5 K. Nitrogen substitutes for oxygen ions and has four nearest-neighbor cations. The zinc ion …

Mechanisms Of Soil Carbon Accrual And Storage In Bioenergy Cropping Systems, Lisa K. Tiemann, A. Stuart Grandy

Faculty Publications

Annual row cropping systems converted to perennial bioenergy crops tend to accrue soil C, likely a function of increased root production and decreased frequency of tillage; however, very little is known about the mechanisms governing the accrual and stability of this additional soil C. To address this uncertainty, we assessed the formation and stability of aggregates and soil organic C (SOC) pools under switchgrass, giant miscanthus, a native perennial grass mix and continuous corn treatments in Michigan and Wisconsin soils differing in both texture and mineralogy. We isolated different aggregate size fractions, >2 mm, 0.5–2 mm, and <0.5 mm, using a procedure intended to minimize alterations to aggregate biological and chemical properties. We determined SOC, permanganate oxidizable C (POXC), and microbial activities (i.e. enzyme activities and soil respiration rates) associated with these aggregates. Soil type strongly influenced the trajectory of aggregate formation and stabilization with differences between sites in mean aggregate size, stability, SOC and microbial activity under perennial vs. corn cropping systems. At the Michigan site, soil microbial activities were highest in the >2 mm aggregates, …

First Searches For Optical Counterparts To Gravitational-Wave Candidate Events, Tiffany Summerscales, Ligo Scientific Collaboration And Virgo Collaboration

Faculty Publications

During the Laser Interferometer Gravitational-wave Observatory and Virgo joint science runs in 2009-2010, gravitational wave (GW) data from three interferometer detectors were analyzed within minutes to select GW candidate events and infer their apparent sky positions. Target coordinates were transmitted to several telescopes for follow-up observations aimed at the detection of an associated optical transient. Images were obtained for eight such GW candidates. We present the methods used to analyze the image data as well as the transient search results. No optical transient was identified with a convincing association with any of these candidates, and none of the GW triggers …

Grading By Response Category: A Simple Method For Providing Students With Meaningful Feedback On Exams In Large Courses, Cassandra Paul, Wendell Potter, Brenda Weiss

Faculty Publications

As instructors, we want our students to develop a deep understanding of course material, and feedback is essential in their sense-making process. Providing effective individualized feedback to students in large courses is especially difficult. While researcherssuggest,1 and many instructors of large courses are,2,3incorporating interactive techniques that allow peer feedback, studies have shown that it's important for students to also have direct feedback from the instructor.4 Since the requirement for individualized feedback is difficult to meet during class time in large courses, providing effective feedback on exams and quizzes takes on added importance. Some instructors choose to …

Sixteen Years Of Collaborative Learning Through Active Sense-Making In Physics (Clasp) At Uc Davis, Wendell Potter, David Webb, Cassandra Paul, Emily West, Mark Bowen, Brenda Weiss, Lawrence Coleman, Charles De Leone

Faculty Publications

This paper describes our large reformed introductory physics course at UC Davis, which bioscience students have been taking since 1996. The central feature of this course is a focus on sense-making by the students during the five hours per week discussion/labs in which the students take part in activities emphasizing peer-peer discussions, argumentation, and presentations of ideas. The course differs in many fundamental ways from traditionally taught introductory physics courses. After discussing the unique features of CLASP and its implementation at UC Davis, various student outcome measures are presented showing increased performance by students who took the CLASP course compared …

Measurement Of D^*\Pm Production In Deep Inelastic Scattering At Hera, Margarita C. K. Mattingly, Zeus Collaboration

Faculty Publications

The production of D^∗± mesons in deep inelastic ep scattering has been measured for exchanged photon virtualities 5 < Q²<1000GeV², using an integrated luminosity of 363 pb⁻¹ with the ZEUS detector at HERA. Differential cross sectionshave been measured and compared to next-to-leading-order QC D calculations. The cross-sections are used to extract the charm contribution to the protonstructure functions, expressed in terms of the reduced charm cro ss section, σ^c̄c_red. Theoretical calculations based on fits to inclusive HERA data are compared to the results.

The 17 May 2012 M4.8 Earthquake Near Timpson, East Texas: An Event Possibly Triggered By Fluid Injection, Cliff Frohlich, William Ellsworth, Wesley A. Brown, Michael Brunt, Jim Luetgert, Tim Macdonald, Steve Walter

Faculty Publications

This study summarizes our investigation of the 17 May 2012 MW‐RMT4.8 earthquake near Timpson, Texas, the largest earthquake recorded historically in eastern Texas. To identify preshocks and aftershocks of the 17 May event we examined the arrivals recorded at Nacogdoches (NATX) 30 km from the 17 May epicenter, at nearby USArray Transportable Array stations, and at eight temporary stations deployed between 26 May 2012 and mid‐2013. At NATX we identified seven preshocks, the earliest occurring in April 2008. Reliably located aftershocks recorded by the temporary stations lie along a 6 km long NW‐SE linear trend corresponding to a …

Winter Movements Of Louisiana Pine Snakes (Pituophis Ruthveni) In Texas And Louisiana, Josh B. Pierce, D. Craig Rudolph, Shirley J. Burgdorf, Richard R. Schaefer, Richard N. Conner, John G. Himes, C. Mike Duran, Laurence M. Hardy, Robert R. Fleet

Faculty Publications

Despite concerns that the Louisiana Pine Snake (Pituophis ruthveni) has been extirpated from large portions of its historic range, only a limited number of studies on their movement patterns have been published. Winter movement patterns are of particular interest since it has been hypothesized that impacts of management practices would be reduced during the winter. Using radiotelemetry, we determined winter movement patterns of Louisiana Pine Snakes (11 males, 8 females) in 5 study areas (2 in Louisiana and 3 in Texas). Movements during winter (November–February) were greatly curtailed compared to the remainder of the year; however, snakes occasionally undertook substantial …