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Selected Works

2015

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Articles 1 - 30 of 1785

Full-Text Articles in Physical Sciences and Mathematics

The Fraud Detection Triangle: A New Framework For Selecting Variables In Fraud Detection Research, Adrian Gepp, Kuldeep Kumar, Sukanto Bhattacharya Feb 2016

The Fraud Detection Triangle: A New Framework For Selecting Variables In Fraud Detection Research, Adrian Gepp, Kuldeep Kumar, Sukanto Bhattacharya

Kuldeep Kumar

The selection of explanatory (independent) variables is crucial to developing a fraud detection model. However, the selection process in prior financial statement fraud detection studies is not standardized. Furthermore, the categories of variables differ between studies. Consequently, the new Fraud Detection Triangle framework is proposed as an overall theory to assist in guiding the selection of variables for future fraud detection research. This new framework adapts and extends Cressey’s (1953) well-known and widely-used fraud triangle to make it more suited for use in fraud detection research. While the new framework was developed for financial statement fraud detection, it is more …


Self-Assembling Biomolecular Catalysts For Hydrogen Production, Dustin Patterson Dec 2015

Self-Assembling Biomolecular Catalysts For Hydrogen Production, Dustin Patterson

Dustin Patterson

The chemistry of highly evolved protein-based compartments has inspired the design of new catalytically active materials that self-assemble from biological components. A frontier of this biodesign is the potential to contribute new catalytic systems for the production of sustainable fuels, such as hydrogen. Here, we show the encapsulation and protection of an active hydrogen-producing and oxygen-tolerant [NiFe]-hydrogenase, sequestered within the capsid of the bacteriophage P22 through directed self-assembly. We co-opted Escherichia coli for biomolecular synthesis and assembly of this nanomaterial by expressing and maturing the EcHyd-1 hydrogenase prior to expression of the P22 coat protein, which subsequently self assembles. By …


Needs Assessment: A Report On Seven Focus Groups In Ohio, Kevin O'Brien, Daniel Baracskay, Wendy Kellogg, Michael Mcgoun, Claudette Robey, Michael Tevesz, Kirstin Toth Dec 2015

Needs Assessment: A Report On Seven Focus Groups In Ohio, Kevin O'Brien, Daniel Baracskay, Wendy Kellogg, Michael Mcgoun, Claudette Robey, Michael Tevesz, Kirstin Toth

Michael J. Tevesz

A series of seven focus groups were conducted in various locations throughout northern Ohio to identify and assess coastal resources management training needs across the Ohio Great Lakes basin. The focus groups were comprised of a cross-section of professionals who make decisions affecting watershed areas or Lake Erie coastal areas. Six of the focus groups included decision-makers considered previous and potential users of coastal resources management training (non-providers). A seventh focus group included decision-makers who provide training in coastal resources management (providers).


Spectroscopic And Functional Characterization Of The Nitric Oxide Adducts Of The Fe(Iii) And Fe(Ii) States Of The Co-Sensing Transcription Factor, Cooa, From Carboxydothermus Hydrogenoformans, Robert Clark, Edra Jani, Arathi Francis, Elise Laroche, Isabel Malone Dec 2015

Spectroscopic And Functional Characterization Of The Nitric Oxide Adducts Of The Fe(Iii) And Fe(Ii) States Of The Co-Sensing Transcription Factor, Cooa, From Carboxydothermus Hydrogenoformans, Robert Clark, Edra Jani, Arathi Francis, Elise Laroche, Isabel Malone

Robert Clark

CooA is a carbon monoxide (CO) sensing transcription factor that is found in several bacteria and regulates CO metabolism. CO binding to CooA’s heme groups initiates a conformation change that activates protein DNA binding. This study investigates the reaction of Fe(III) Carboxydothermus hydrogenoformansCooA (Ch CooA) with nitric oxide (NO). Previously, Clark and coworkers reported Fe(II) Ch CooA bound NO to form a 6-coordinate (6-C) Fe(II)-NO adduct that was active for DNA binding in vivo and in vitro. This is in contrast to the best studied CooA homolog from R. rubrum (Rr) that was exquisitely specific for CO and formed an …


The Effect Of Latency On User Performance In Warcraft Iii, Nathan Sledon, Eric Girard, Seth Borg, Mark Claypool, Emmanuel Agu Dec 2015

The Effect Of Latency On User Performance In Warcraft Iii, Nathan Sledon, Eric Girard, Seth Borg, Mark Claypool, Emmanuel Agu

Emmanuel O. Agu

Variable latency on the Internet is a well-known problem for interactive applications. With the increase in interactive network games comes the increased importance of understanding the effects of latency on user performance. Classes of network games such as First Person Shooters (FPS) and Read Time Strategy (RTS) differ in their user interaction model and hence susceptibility to variable latency. While previous work has measured the effects of latency on FPS games, there has been no systematic investigation of the effects of latency on RTS games. In this work, we design and conduct user studies that measure the impact of latency …


Low Delay Marking For Tcp In Wireless Ad Hoc Networks, Choong-Soo Lee, Mingzhe Li, Emmanuel Agu, Mark Claypool, Robert Kinicki Dec 2015

Low Delay Marking For Tcp In Wireless Ad Hoc Networks, Choong-Soo Lee, Mingzhe Li, Emmanuel Agu, Mark Claypool, Robert Kinicki

Emmanuel O. Agu

End-hosts on wireless ad hoc networks typically use TCP as their transport layer protocol. Being designed for wired networks, TCP can perform poorly over wireless networks. Work that has proposed ways to improve TCP performance over wireless networks has concentrated primarily on improving TCP throughput only. Emerging applications, such as interactive multimedia and network games, require reduced delay at least as much as increased throughput. In this paper, we propose LDM1, an IP layer queue marking mechanism that estimates the number of hops and flows at each wireless node to computes the optimal marking probability. We present simulation results and …


Full Isolation Number Of Matrices: Some Extremal Results, David Tate, David Brown Dec 2015

Full Isolation Number Of Matrices: Some Extremal Results, David Tate, David Brown

David C. Brown

A set of nonzero entries of a (0,1)-matrix is an isolated set if no two entries belong to the same row, no two entries belong to the same column, and no two entries belong to a submatrix of the form [1 1; 1 1]. The isolation number of a matrix is the maximum size over all isolated sets. The isolation number of a matrix is a well-known and well-used lower bound for the matrix's Boolean rank. We will discuss the isolation number of the adjacency matrix of various graphs and develop some extremal results for n x n matrices with …


Use Of Cryoelectronics To Reduce Power Losses, Christopher Hawley, Steve Gower, Dominic Cuiuri Dec 2015

Use Of Cryoelectronics To Reduce Power Losses, Christopher Hawley, Steve Gower, Dominic Cuiuri

Dominic Cuiuri

The operational characteristics of power electronics operating at ambient temperatures are well known. Less well known are the characteristics of these devices when operating at cryogenic temperatures. This emerging field is known as cryoelectronics. The primary driver for operation at reduced temperatures is the promise of a resultant reduction in device operation losses. The operating characteristics of Metal Oxide Silicon Field Effect Transistors (MOSFETs) and Insulated Gate Bipolar Transistors (IGBTs) at Liquid Nitrogen (LN) temperature have been experimentally analysed. The results have been used to evaluate the viability of using cryoelectronics in medium - high power applications, considering trade-offs between …


Time-Partitioned Index Design For Adaptive Multi-Route Data Stream Systems Utilizing Heavy Hitter Algorithms, Karen Works, Elke Rundensteiner, Emmanuel Agu Dec 2015

Time-Partitioned Index Design For Adaptive Multi-Route Data Stream Systems Utilizing Heavy Hitter Algorithms, Karen Works, Elke Rundensteiner, Emmanuel Agu

Emmanuel O. Agu

Adaptive multi-route query processing (AMR) is a recently emerging paradigm for processing stream queries in highly fluctuating environments. AMR dynamically routes batches of tuples to operators in the query network based on routing criteria and up-to-date system statistics. In the context of AMR systems, indexing, a core technology for efficient stream processing, has received little attention. Indexing in AMR systems is demanding as indices must adapt to serve continuously evolving query paths while maintaining index content under high volumes of data. Our proposed Adaptive Multi-Route Index (AMRI) employs a bitmap time-partitioned design that while being versatile in serving a diverse …


Harmonic Allocation Following Iec Guidelines Using The Voltage Droop Concept, V. Gosbell, Robert Barr Dec 2015

Harmonic Allocation Following Iec Guidelines Using The Voltage Droop Concept, V. Gosbell, Robert Barr

Robert Barr

Present IEC guidelines are difficult to apply to realistic cases because of the data load, the number of assumptions required and the computational complexity. A new approach is given based on the concept of voltage droop, to be detailed in a companion paper. The benefits of the approach are a simple calculation with minimal data and no required assumptions. It applies to radial or meshed distribution systems where feeders are sufficiently short that line capacitance can be ignored. The approach can be applied at the installation (MV or LV) and the equipment level and can be used to give reference …


New Exactly Solvable Hamiltonians - Shape Invariance And Self-Similarity, David Barclay, Ranabir Dutt, Asim Gangopadhyaya, Avinash Khare, A. Pagnamenta, Uday Sukhatne Dec 2015

New Exactly Solvable Hamiltonians - Shape Invariance And Self-Similarity, David Barclay, Ranabir Dutt, Asim Gangopadhyaya, Avinash Khare, A. Pagnamenta, Uday Sukhatne

Asim Gangopadhyaya

We discuss in some detail the self-similar potentials of Shabat and Spiridonov which are reflectionless and have an infinite number of bound states. We demonstrate that these self-similar potentials are in fact shape invariant potentials within the formalism of supersymmetric quantum mechanics. In particular, using a scaling ansatz for the change of parameters, we obtain a large class of new, reflectionless, shape invariant potentials of which the Shabat-Spiridonov ones are a special case. These new potentials can be viewed as q-deformations of the single soliton solution corresponding to the Rosen-Morse potential. Explicit expressions for the energy eigenvalues, eigenfunctions and transmission …


Performance Enhancement Of Tfrc In Wireless Networks, Mingzhe Li, Emmanuel Agu, Mark Claypool, Robert Kinicki Dec 2015

Performance Enhancement Of Tfrc In Wireless Networks, Mingzhe Li, Emmanuel Agu, Mark Claypool, Robert Kinicki

Emmanuel O. Agu

The TCP-Friendly Rate Control (TFRC) is used as a streaming media transport protocol. Using the TCP congestion response function and current network conditions, TFRC adjusts its transmission rate to yield the maximum TCP-Friendly throughput when sharing capacity with TCP flows. Since TFRC was designed for wired networks, it does not achieve the maximum TCP-Friendly throughput in multihop ad hoc wireless networks. The reduced wireless spatial channel reuse due to hidden terminals in multihop wireless networks induces TFRC throughput reductions. Specifically, TFRC is unaware of MAC layer transmission delays due to collisions, retransmissions and MAC layer congestion. This paper illustrates that …


Nilgai Antelope In Northern Mexico As A Possible Carrier For Cattle Fever Ticks And Babesia Bovis And Babesia Bigemina., E Cardenas-Canales, J. Alfonso Ortega-Santos, Tyler A. Campbell, Zeferino Garcia-Vaquez, Antonio Cantu-Covarrubias, Julio Figueroa-Millian, Randy W. Deyoung, David G. Hewitt, Fred Bryant Dec 2015

Nilgai Antelope In Northern Mexico As A Possible Carrier For Cattle Fever Ticks And Babesia Bovis And Babesia Bigemina., E Cardenas-Canales, J. Alfonso Ortega-Santos, Tyler A. Campbell, Zeferino Garcia-Vaquez, Antonio Cantu-Covarrubias, Julio Figueroa-Millian, Randy W. Deyoung, David G. Hewitt, Fred Bryant

Fred B. Bryant

Of 20 blood samples from nilgais from Me´ xico, five were polymerase chain reaction-positive for Babesia bigemina and one for Babesia bovis. Positive samples had the expected 170 (B. bigemina) and 291 (B. bovis) base pairs and were identical to Gen-Bank B. bigemina accession S45366 and B. bovis M38218.


Generation Of A Complete Set Of Additive Shape-Invariant Potentials From An Euler Equation, Jonathan Bougie, Asim Gangopadhyaya, Jeffrey Mallow Dec 2015

Generation Of A Complete Set Of Additive Shape-Invariant Potentials From An Euler Equation, Jonathan Bougie, Asim Gangopadhyaya, Jeffrey Mallow

Asim Gangopadhyaya

In supersymmetric quantum mechanics, shape invariance is a sufficient condition for solvability. We show that all conventional additive shape-invariant superpotentials that are independent of ħ can be generated from two partial differential equations. One of these is equivalent to the one-dimensional Euler equation expressing momentum conservation for inviscid fluid flow, and it is closed by the other. We solve these equations, generate the set of all conventional shape-invariant superpotentials, and show that there are no others in this category. We then develop an algorithm for generating all additive shape-invariant superpotentials including those that depend on ħ explicitly.


Supersymmetry And The Tunneling Problem In An Asymmetric Double Well, Asim Gangopadhyaya, Prasanta Panigrahi, Uday Sukhatne Dec 2015

Supersymmetry And The Tunneling Problem In An Asymmetric Double Well, Asim Gangopadhyaya, Prasanta Panigrahi, Uday Sukhatne

Asim Gangopadhyaya

The techniques of supersymmetric quantum mechanics are applied to the calculation of the energy difference between the ground state and the first excited state of an asymmetric double well. This splitting, originating from the tunneling effect, is computed via a systematic, rapidly converging perturbation expansion. Perturbative calculations to any order can be easily carried out using a logarithmic perturbation theory. Our approach yield substantially better results than alternative widely used semiclassical analyses.


Mechanism Of Redox- And Co-Sensing By The Heme Protein, Cooa: Cryoradiolysis Studies, Robert Clark, Deanna Kalafut Dec 2015

Mechanism Of Redox- And Co-Sensing By The Heme Protein, Cooa: Cryoradiolysis Studies, Robert Clark, Deanna Kalafut

Robert Clark

Gas-sensing heme proteins participate in a variety of signal-transduction mechanisms across a broad range of biological systems. This class of proteins functions by undergoing an allosteric conformational change in response to the binding of a small gas molecule to a heme group. CooA, which is a redox- and CO-sensing transcription factor that is found in several bacteria, regulates gene expression that enables growth on CO as a sole energy source. In the current study, we have employed the technique of gamma-irradiation / cryoreduction spectroscopy (cryoradiolysis) to investigate facile changes that occur to the heme coordination structure of CooA during activation. …


Holocene Climatic Change And Past Irish Societal Response, David Brown, M. Baillie, J. Palmer, Christian Turney Dec 2015

Holocene Climatic Change And Past Irish Societal Response, David Brown, M. Baillie, J. Palmer, Christian Turney

David C. Brown

No abstract provided.


Discovering A Research Agenda For Using Design Rationale In Software Maintenance, Janet Burge, David Brown Dec 2015

Discovering A Research Agenda For Using Design Rationale In Software Maintenance, Janet Burge, David Brown

David C. Brown

Design Rationale consists of the reasons behind decisions made while designing. This information would be particularly useful during software maintenance. In this paper, we describe a study performed to investigate the content, structure, and use of design rationale during maintenance. The major goal of this study was to discover an agenda for further research into the use of design rationale for software maintenance.


Measuring The Performance Gains From Directional Antennas In An Unplanned 802.11b Mesh Network, Jason Wilson, Patrick Gemme, Emmanuel Agu Dec 2015

Measuring The Performance Gains From Directional Antennas In An Unplanned 802.11b Mesh Network, Jason Wilson, Patrick Gemme, Emmanuel Agu

Emmanuel O. Agu

Wireless mesh networks are becoming increasingly popular. Most proposed mesh algorithms are evaluated using simulation. Simulations frequently oversimplify real world scenarios and can lead to results that are significantly different. Thus, although it is more difficult to run controlled experiments in already deployed real-world networks, it is important to understand how proposed improvements perform under these realistic scenarios. Several authors have suggested the use of directional antennas, but their merits have only comprehensively evaluated in simulators. Roofnet is an unplanned 802.11b wireless mesh network deployed by MIT and is constructed primarily of omni-directional antennas. We use measurements to evaluate performance …


Inferring Unobservable Learning Variables From Students’ Help Seeking Behavior, Ivon Arroyo Dec 2015

Inferring Unobservable Learning Variables From Students’ Help Seeking Behavior, Ivon Arroyo

Ivon Arroyo

Results of an evaluation of students’ attitudes and their relationship to student behaviors within a tutoring system are presented. Starting from a correlation analysis that integrates survey-collected student attitudes, learning variables, and behaviors while using the tutor, we constructed a Bayesian Network that infers attitudes and perceptions towards help and the tutoring system.


Coastal Resources Management Training Needs Assessment: Strategies And Opportunities, Kevin O'Brien, Claudette Robey, Wendy Kellogg, Michael Tevesz Dec 2015

Coastal Resources Management Training Needs Assessment: Strategies And Opportunities, Kevin O'Brien, Claudette Robey, Wendy Kellogg, Michael Tevesz

Michael J. Tevesz

The Old Woman Creek National Estuarine Research Reserve (OWC), Ohio Department of Natural Resources-Coastal Management Program (ODNRCMP), and Ohio Sea Grant College Program engaged the Great Lakes Environmental Finance Center (GLEFC) to aid them in developing a coastal resources management training initiative for Ohio coastal decision-makers. Coastal decision-maker professionals are expected to formulate effective strategies and apply interdisciplinary approaches to solving problems and policy issues that affect the environments of coastal regions. There are a number of professionals in a variety of occupations who make decisions regarding coastal and environmental policy issues. These individuals include those within the coastal resources …


Silica-Bound Copper(Ii) Triazacyclononane As A Phosphate Esterase: Effect Of Linker Length And Surface Hydrophobicity, Brett Bodsgard, Robert Clark, Anthony Ehrbar, Judith Burstyn Dec 2015

Silica-Bound Copper(Ii) Triazacyclononane As A Phosphate Esterase: Effect Of Linker Length And Surface Hydrophobicity, Brett Bodsgard, Robert Clark, Anthony Ehrbar, Judith Burstyn

Robert Clark

A series of silica-bound Cu(II) triazacyclononane materials was prepared to study the effect of linker length and surface hydrophobicity on the hydrolysis of phosphate esters. The general synthetic approach for these heterogeneous reagents was rhodium-catalyzed hydrosilation between an alkenyl-modified triazacyclononane and hydride-modified silica followed by metallation with a Cu(II) salt. Elemental analysis confirmed that organic functionalization of the silica gel was successful and provided an estimate of the surface concentration of triazacyclononane. EPR spectra were consistent with square pyramidal Cu(II), indicating that Cu(II) ions were bound to the immobilized macrocycles. The hydrolytic efficacies of these heterogeneous reagents were tested with …


Magnet Traveling Through A Conducting Pipe: A Variation On The Analytical Approach, Benjamin Irvine, Matthew Kemnetz, Asim Gangopadhyaya, Thomas Ruubel Dec 2015

Magnet Traveling Through A Conducting Pipe: A Variation On The Analytical Approach, Benjamin Irvine, Matthew Kemnetz, Asim Gangopadhyaya, Thomas Ruubel

Asim Gangopadhyaya

We present an analytical study of magnetic damping. In particular, we investigate the dynamics of a cylindrical neodymium magnet as it moves through a conducting tube. Owing to the very high degree of uniformity of the magnetization for neodymium magnets, we are able to provide completely analytical results for the electromotive force generated in the pipe and the consequent retarding force. Our analytical expressions are shown to have excellent agreement with experimental observations.


Noncentral Potentials And Spherical Harmonics Using Supersymmetry And Shape Invariance, Ranabir Dutt, Asim Gangopadhyaya, Uday Sukhatne Dec 2015

Noncentral Potentials And Spherical Harmonics Using Supersymmetry And Shape Invariance, Ranabir Dutt, Asim Gangopadhyaya, Uday Sukhatne

Asim Gangopadhyaya

It is shown that the operator methods of supersymmetric quantum mechanics and the concept of shape invariance can profitably be used to derive properties of spherical harmonics in a simple way. The same operator techniques can also be applied to several problems with noncentral vector and scalar potentials. As examples, we analyze the bound state spectra of an electron in a Coulomb plus an Aharonov – Bohm field and/or in the magnetic field of a Dirac monopole.


Isomer Distribution Of Succinylcyclohexenyl, Acetylcyclohexenyl And Acetylcyclopentenyl Enamines, A. Cook, Sarah Folk Dec 2015

Isomer Distribution Of Succinylcyclohexenyl, Acetylcyclohexenyl And Acetylcyclopentenyl Enamines, A. Cook, Sarah Folk

A. Gilbert Cook

The isomeric distributions of some cyclohexenyl enamines substituted by succinyl or acetyl groups at either the 2- or 6-positions are reported as are the isomeric distributions of similarly substituted cyclopentenyl enamines. Correlation between the C-13 NMR chemical shifts in these enamines and isomer distribution is shown. Density functional molecular modeling is used to demonstrate resonance and electrostatic effects on isomeric distributions.


Bipartite Probe Interval Graphs, Interval Point Bigraphs, And Circular Arcgraphs, David Brown, J. Lundgren Dec 2015

Bipartite Probe Interval Graphs, Interval Point Bigraphs, And Circular Arcgraphs, David Brown, J. Lundgren

David C. Brown

No abstract provided.


Supersymmetric Quantum Mechanics And Solvable Models, Asim Gangopadhyaya, Jonathan Bougie, Jeffrey Mallow, C. Rasinariu Dec 2015

Supersymmetric Quantum Mechanics And Solvable Models, Asim Gangopadhyaya, Jonathan Bougie, Jeffrey Mallow, C. Rasinariu

Asim Gangopadhyaya

We review solvable models within the framework of supersymmetric quantum mechanics (SUSYQM). In SUSYQM, the shape invariance condition insures solvability of quantum mechanical problems. We review shape invariance and its connection to a consequent potential algebra. The additive shape invariance condition is specified by a difference-differential equation; we show that this equation is equivalent to an infinite set of partial differential equations. Solving these equations, we show that the known list of h-independent superpotentials is complete. We then describe how these equations could be extended to include superpotentials that do depend on h.


Web-Based Intelligent Multimedia Tutoring For High Stakes Achievement Tests, Ivon Arroyo Dec 2015

Web-Based Intelligent Multimedia Tutoring For High Stakes Achievement Tests, Ivon Arroyo

Ivon Arroyo

We describe Wayang Outpost, a web-based ITS for the Math section of the Scholastic Aptitude Test (SAT). It has several distinctive features: help with multimedia animations and sound, problems embedded in narrative and fantasy contexts, alternative teaching strategies for students of different mental rotation abilities and memory retrieval speeds. Our work on adding intelligence for adaptivity is described. Evaluations prove that students learn with the tutor, but learning depends on the interaction of teaching strategies and cognitive abilities. A new adaptive tutor is being built based on evaluation results; surveys results and students’ log files analyses.


Trends Analysis Of Coastal Training Programs In The National Estuarine Research Reserve System: Executive Summary, Claudette Robey, Kevin O'Brien, Kirstin Toth, Dan Baracksay, Michael Mcgoun, Wendy Kellogg, Michael Tevesz Dec 2015

Trends Analysis Of Coastal Training Programs In The National Estuarine Research Reserve System: Executive Summary, Claudette Robey, Kevin O'Brien, Kirstin Toth, Dan Baracksay, Michael Mcgoun, Wendy Kellogg, Michael Tevesz

Michael J. Tevesz

No abstract provided.


Land-Use Pattern, Urbanization, And Deer–Vehicle Collisions In Alabama, Anwar Hussain, James Armstrong, David Brown, John Hogland Dec 2015

Land-Use Pattern, Urbanization, And Deer–Vehicle Collisions In Alabama, Anwar Hussain, James Armstrong, David Brown, John Hogland

David C. Brown

With the rise in deer–vehicle collisions across the United States, the associated costs also have risen. Increasingly, however, researchers are learning that these collisions are not a random phenomena but follow a systematic pattern. Building on this insight, we explored the role of county characteristics in influencing the pattern and incidence of white-tailed deer- (Odocoileus virginianus) related auto collisions. Using county level data from 1994 to 2003 in Alabama, we tested several data models with the above mentioned factors …