Digital Commons Network^™

Multivariate Thinking In An Intro Stats Course – Is It Possible?, Beverly Wood

Publications

Many of our students have an intuitive sense that there is more to the story than univariate or bivariate data can tell us. We can acknowledge and encourage that habit of digging deeper by demonstrating some ways to look at additional variables. Simpson’s paradox and side-by-side scatter plots are ways to provide a glimpse of more complex analysis that are accessible to students in an introductory course with or without strong quantitative skills.

The Deep Propagating Gravity Wave Experiment (Deepwave): An Airborne And Ground-Based Exploration Of Gravity Wave Propagation And Effects From Their Sources Throughout The Lower And Middle Atmosphere, David C. Fritts, Ronald B. Smith, Michael J. Taylor, James D. Doyle, Stephen D. Eckermann, Andreas Dörnbrack, Markus Rapp, Bifford P. Williams, Pierre-Dominique Pautet, Katrina Bossert, Neal R. Criddle, Carolyn A. Reynolds, P. Alex Reineke, Michael Uddstrom, Michael J. Revell, Richard Turner, Bernd Kaifler, Johannes S. Wagner, Tyler Mixa, Christopher G. Kruse, Alison D. Nugent, Campbell D. Watson, Sonja Gisinger, Steven M. Smith, James J. Moore, William O. Brown, Julie A. Haggerty, Alison Rockwell, Gregory J. Stossmeister, Et Al. Et Al.

Publications

The Deep Propagating Gravity Wave Experiment (DEEPWAVE) was designed to quantify gravity wave (GW) dynamics and effects from orographic and other sources to regions of dissipation at high altitudes. The core DEEPWAVE field phase took place from May through July 2014 using a comprehensive suite of airborne and ground-based instruments providing measurements from Earth’s surface to ∼100 km. Austral winter was chosen to observe deep GW propagation to high altitudes. DEEPWAVE was based on South Island, New Zealand, to provide access to the New Zealand and Tasmanian “hotspots” of GW activity and additional GW sources over the Southern Ocean and …

Energy Transfer From Wind To Wave Groups: Theory And Experiment, Andrei Ludu, Shahrdad G. Sajjadi

Publications

Three major unresolved problems that remain in oceanography are studied in depth, namely (a) unsteady waves, where waves are allowed to grow or decay in time and space; (b) sharp-crested waves (also known as fully nonlinear Stoke waves), which are note characteristic in oceans; and (c) group of waves, which can often become sharp crested as they propagate downstream, as demonstrated here experimentally in a wave tank. The ultimate aim of such investigation is to improve the parameterization of the energy input from wind to waves. In this paper, we (i) present results on the simplest approximation to wave groups …

The Writing Attitude Scale For Teachers (Wast), Anna H. Hall

Publications

This study examines the psychometric properties of the Writing Attitude Scale for Teachers (WAST) using scores of preservice teachers to gather evidence of content, internal structure, response processes, reliability/precision, and correlations with external variables. Four contending models were compared using CFA, but the unidimensional model was championed. The WAST was further refined using IRT to 10-items and shown to have high precision across most of the latent continuum. The WAST was shown to have incremental evidence relative to the Writing Apprehension Test when predicting attitudes towards attending a professional development workshop on writing instruction and time devoted to writing instruction.

Ion Transport Through Macrocapillaries – Oscillations Due To Charge Patch Formation, Dhruva Kulkarni, L.A.M. Lyle, Chad E. Sosolik

Publications

We present results on ion transport through large bore capillaries (macrocapillaries) that probe both the geometric and ion-guided aspects of this ion delivery mechanism. We have demonstrated that guiding in macrocapillaries exhibits position- and angle-dependent transmission properties which are directly related to the capillary material (either metal or insulator) and geometry. Specifically, we have passed 1 keV Rb⁺ ions through glass and metal macrocapillaries, and have observed oscillations for the transmitted ion current passing through the insulating capillaries. Straightforward calculations show that these oscillations can be attributed to beam deflections from charge patches that form on the interior walls …

Development And Use Of A Tablet-Based Resuscitation Sheet For Improving Outcomes During Intensive Patient Care, Wasif Bokahri, Vimla L. Patel, Ashish Amresh, Ayan Sen

Publications

Data documentation from resuscitation events in hospitals, termed "code blue" events, utilizes a paper form, which is institution-specific. Problems with data capture and transcription exists, due to the challenges of dynamic documentation of patient, event and outcome variables as the code blue event unfolds. We hypothesize that an electronic version of code blue real-time data capture would lead to improved resuscitation data transcription, and enable clinicians to address deficiencies in quality of care. To this effect, we present the design of a tablet-based application and its use by 20 nurses at the Mayo Clinic hospital. The results showed that the …

Growth Of Stokes Waves Induced By Wind On A Viscous Liquid Of Infinite Depth, Shahrdad Sajjadi

Publications

The original investigation of Lamb (1932, x349) for the effect of viscosity on monochromatic surface waves is extended to account for second-order Stokes surface waves on deep water in the presence of surface tension. This extension is used to evaluate interfacial impedance for Stokes waves under the assumption that the waves are growing and hence the surface waves are unsteady. Thus, the previous investigation of Sajjadi et al. (2014) is further explored in that (i) the surface wave is unsteady and nonlinear, and (ii) the effect of the water viscosity, which affects surface stresses, is taken into account. The determination …

Relaxations And Discretizations For The Pooling Problem, Akshay Gupte, Shabbir Ahmed, Santanu S. Dey, Myun Seok Cheon

Publications

The pooling problem is a folklore NP-hard global optimization problem that finds applications in industries such as petrochemical refining, wastewater treatment and mining. This paper assimilates the vast literature on this problem that is dispersed over different areas and gives new insights on prevalent techniques. We also present new ideas for computing dual bounds on the global optimum by solving high-dimensional linear programs. Finally, we propose discretization methods for inner approximating the feasible region and obtaining good primal bounds. Valid inequalities are derived for the discretized models, which are formulated as mixed integer linear programs. The strength of our relaxations …

Integrable Abel Equations And Vein's Abel Equation, S.C. Mancas, Haret C. Rosu

Publications

We first reformulate and expand with several novel findings some of the basic results in the integrability of Abel equations. Next, these results are applied to Vein’s Abel equation whose solutions are expressed in terms of the third order hyperbolic functions and a phase space analysis of the corresponding nonlinear oscillator is also provided.

What Moser Could Have Asked: Counting Hamilton Cycles In Tournaments, Neil J. Calkin, Beth Novick, Hayato Ushijima-Mwesigwa

Publications

Moser asked for a construction of explicit tournaments on n vertices having at least Hamilton cycles. We show that he could have asked rather more.

Book Review: Moons Of The Solar System: From Giant Ganymede To Dainty Dactyl, T. D. Oswalt

Publications

This document is Dr. Oswalt’s review of Moons of the Solar System : from Giant Ganymede to Dainty Dactyl by James A. Hall, III. Springer 2015. 297p index afp, 9783319206356 $34.99, 9783319206363 $19.99

Conversations About Diversity: Institutional Barriers For Underrepresented Engineering Students, Leroy Long Iii, Joel Alejandro Mejia

Publications

The United States is becoming increasingly more diverse. Specifically, demographics are shifting because of growth among historically underrepresented racial and ethnic minorities, including African Americans, Latinos, and Native Americans. At the same time, a declining number of skilled workers in science, technology, engineering, and mathematics (STEM) fields threatens U.S. global competitiveness and national security. Low participation, representation, engagement, and inclusion continue to reduce the intellectual capacity of the U.S. STEM workforce. The aforementioned societal changes require diversity in STEM education and the nation at large. Past research offers additional support for the importance of diversity. For example, racial diversity can …

An Overview Of Cryptography (Updated Version, 3 March 2016), Gary C. Kessler

Publications

There are many aspects to security and many applications, ranging from secure commerce and payments to private communications and protecting passwords. One essential aspect for secure communications is that of cryptography...While cryptography is necessary for secure communications, it is not by itself sufficient. This paper describes the first of many steps necessary for better security in any number of situations.

A much shorter, edited version of this paper appears in the 1999 edition of Handbook on Local Area Networks published by Auerbach in September 1998.

Factors Associated With Anaplasma Spp. Seroprevalence Among Dogs In The United States, Christopher S. Mcmahan, Dongmei Wang, Melissa J. Beall, Dwight D. Bowman, Susan E. Little, Patrick O. Pithua, Julia L. Sharp, Roger W. Stich, Michael J. Yabsley, Robert B. Lund

Publications

Background

Dogs in the United States are hosts to a diverse range of ticks and tick-borne pathogens, including A. phagocytophilum, an important emerging canine and human pathogen. Previously, a Companion Animal Parasite Council (CAPC)-sponsored workshop proposed factors purported to be associated with the infection risk for tick-transmitted pathogens in dogs in the United States, including climate conditions, socioeconomic characteristics, local topography, and vector distribution.

Methods

Approximately four million test results from routine veterinary diagnostic tests from 2011–2013, which were collected on a county level across the contiguous United States, are statistically analyzed with the proposed factors via logistic regression …

Observation Of Gravitational Waves From A Binary Black Hole Merger, B. P. Abbott, K. Gill, B. Hughey, M, J. Szczepańczyk, M. Zanolin, Et Al.

Publications

On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-Wave Observatory simultaneously observed a transient gravitational-wave signal. The signal sweeps upwards in frequency from 35 to 250 Hz with a peak gravitational-wave strain of 1.0×10−21. It matches the waveform predicted by general relativity for the inspiral and merger of a pair of black holes and the ringdown of the resulting single black hole. The signal was observed with a matched-filter signal-to-noise ratio of 24 and a false alarm rate estimated to be less than 1 event per 203 000 years, equivalent to a significance greater …

Thermoelastic Waves In Microstructured Solids, Arkadi Berezovski, Mihhail Berezovski

Publications

Thermoelastic wave propagation suggests a coupling between elastic deformation and heat conduction in a body. Microstructure of the body influences the both processes. Since energy is conserved in elastic deformation and heat conduction is always dissipative, the generalization of classical elasticity theory and classical heat conduction is performed differently. It is shown in the paper that a hyperbolic evolution equation for microtemperature can be obtained in the framework of the dual internal variables approach keeping the parabolic equation for the macrotemperature. The microtemperature is considered as a macrotemperature fluctuation. Numerical simulations demonstrate the formation and propagation of thermoelastic waves in …

Synchronization Of Pulse-Coupled Oscillators To A Global Pacemaker, Felipe Nunez, Yongqiang Wang, Andrew R. Teel, Francis J. Doyle Iii

Publications

Pulse-coupled oscillators (PCOs) are limit cycle oscillators coupled by exchanging pulses at discrete time instants. Their importance in biology and engineering has motivated numerous studies aiming to understand the basic synchronization properties of a network of PCOs. In this work, we study synchronization of PCOs subject to a global pacemaker (or global cue) and local interactions between slave oscillators. We characterize solutions and give synchronization conditions using the phase response curve (PRC) as the design element, which is restricted to be of the delay type in the first half of the cycle, interval (0,π)(0,π), and of the advance type in …

Performance Considerations Of Network Functions Virtualization Using Containers, Jason Anderson, Udit Agarwal, Hongda Li, Hongxin Hu, Craig Lowery, Amy W. Apon

Publications

The network performance of virtual machines plays a critical role in Network Functions Virtualization (NFV), and several technologies have been developed to address hardware-level virtualization shortcomings. Recent advances in operating system level virtualization and deployment platforms such as Docker have made containers an ideal candidate for high performance application encapsulation and deployment. However, Docker and other solutions typically use lower-performing networking mechanisms. In this paper, we explore the feasibility of using technologies designed to accelerate virtual machine networking with containers, in addition to quantifying the network performance of container-based VNFs compared to the state-of-the-art virtual machine solutions. Our results show …

Lift & Drag Reductions On Iced Wings During Take Off And Landing With Unmanned Aerial Vehicles, Ian R. Mcandrew

Publications

This research paper addresses an novel problem that has not been addressed in detail for many decades. Ice formation on aircraft has procedures and protocols to deal with expected and actual problems. Complex modern aircraft are equipped with a variety of techniques to remove Ice formation on an aircraft, especially the wings. The introduction of Unmanned Aerial Vehicles has added an old problem, that of low speed and the lack of power to overcome losses in lift through ice formation. In this research the different types of Ice formation, how they combine and affect Lift and Drag are also addresses …

Evolution Of Spherical Cavitation Bubbles: Parametric And Closed-Form Solutions, S.C. Mancas, Haret C. Rosu

Publications

We present an analysis of the Rayleigh-Plesset equation for a three dimensional vacuous bubble in water. In the simplest case when the effects of surface tension are neglected, the known parametric solutions for the radius and time evolution of the bubble in terms of a hypergeometric function are briefly reviewed. By including the surface tension, we show the connection between the Rayleigh-Plesset equation and Abel’s equation, and obtain the parametric rational Weierstrass periodic solutions following the Abel route. In the same Abel approach, we also provide a discussion of the nonintegrable case of nonzero viscosity for which we perform a …

Glide Effects On Low Speed Unmanned Aerial Vehicles With Ice Formation, I. Mcandrew, K. Witcher, E. Navarro

Publications

This paper builds on the research that was previously presented and defended at a conference and adds to the depth of glide characteristics and aerodynamics. The basic assumed theory of low speed flight is used as the starting point and determined if this holds true for low speed. Traditionally, flight has always been about achieving faster and high flight operations. Unmanned Aerial Vehicles (UAV) are not typically designed to fly fast, the construction and power units are limiting, added to the lack of complexity in propulsion systems prevents high speeds in most cases. Here, aerodynamic data for Ice on leading …

Measuring The Seeds Of Ion Outflow: Auroral Sounding Rocket Observations Of Low-Altitude Ion Heating And Circulation, P. A. Fernandes, K. A. Lynch, M. Zettergren, D. L. Hampton, T. A. Bekkeng, Et Al.

Publications

We present an analysis of in situ measurements from the MICA (Magnetosphere-Ionosphere Coupling in the Alfvén Resonator) nightside auroral sounding rocket with comparisons to a multifluid ionospheric model. MICA made observations at altitudes below 325 km of the thermal ion kinetic particle distributions that are the origins of ion outflow. Late flight, in the vicinity of an auroral arc, we observe frictional processes controlling the ion temperature. Upflow of these cold ions is attributed to either the ambipolar field resulting from the heated electrons or possibly to ion-neutral collisions. We measure convection away from the arc (poleward) and downflows of …

Evidence Of Dispersion And Refraction Of A Spectrally Broad Gravity Wave Packet In The Mesopause Region Observed By The Na Lidar And Mesospheric Temperature Mapper Above Logan, Utah, Tao Yuan, Christopher J. Heale, Jonathan B. Snively, Xuguang Cai, Pierre-Dominique Pautet, C. Fish, Yucheng Zhao, Michael J. Taylor, William R. Pendleton Jr., V. Wickwar, Nicholas John Mitchell

Publications

Gravity wave packets excited by a source of finite duration and size possess a broad frequency and wave number spectrum and thus span a range of temporal and spatial scales. Observing at a single location relatively close to the source, the wave components with higher frequency and larger vertical wavelength dominate at earlier times and at higher altitudes, while the lower frequency components, with shorter vertical wavelength, dominate during the latter part of the propagation. Utilizing observations from the Na lidar at Utah State University and the nearby Mesospheric Temperature Mapper at Bear Lake Observatory (41.9°N, 111.4°W), we investigate a …

Evidence Of Dispersion And Refraction Of A Spectrally Broad Gravity Wave Packet In The Mesopause Region Observed By The Na Lidar And Mesospheric Temperature Mapper Above Logan, Utah, T. Yuan, C. J. Heale, J. B. Snively, X. Cai, P.- D. Pautet, C. Fish, Y. Zhao, M. J. Taylor, W. R. Pendleton Jr., V. Wickwar, N. J. Mitchell

Publications

"Gravity wave packets excited by a source of finite duration and size possess a broad frequency and wave number spectrum and thus span a range of temporal and spatial scales. Observing at a single location relatively close to the source, the wave components with higher frequency and larger vertical wavelength dominate at earlier times and at higher altitudes, while the lower frequency components, with shorter vertical wavelength, dominate during the latter part of the propagation. Utilizing observations fromthe Na lidar at Utah State University and the nearby Mesospheric Temperature Mapper at Bear Lake Observatory (41.9°N, 111.4°W), we investigate a unique …

Signal Flow Graph Approach To Efficient Dst I-Iv Algorithms, Sirani M. Perera

Publications

In this paper, fast and efficient discrete sine transformation (DST) algorithms are presented based on the factorization of sparse, scaled orthogonal, rotation, rotation-reflection, and butterfly matrices. These algorithms are completely recursive and solely based on DST I-IV. The presented algorithms have low arithmetic cost compared to the known fast DST algorithms. Furthermore, the language of signal flow graph representation of digital structures is used to describe these efficient and recursive DST algorithms having (n�1) points signal flow graph for DST-I and n points signal flow graphs for DST II-IV.

New Metric For Defining The Time Of Extratropical Transition Of Tropical Cyclones, Ajay Raghavendra, Shawn M. Milrad

Publications

Almost half of all tropical cyclones (TCs) in the Atlantic basin undergo extratropical transition (ET). During an ET event, wind fields often expand dramatically, resulting in more widely-felt impacts. Moreover, the heaviest precipitation typically shifts to the left-of-center (LOC), which can result in inland flash flooding hundreds of kilometers from the cyclone center. While several objective metrics to track and predict ET have been developed, they rely at least partially on internal tropical cyclone structure, for which numerical models show less skill. Further, these metrics fail to account for static stability, which plays a vital role in determining precipitation amounts. …

How Uncertainty In The Neutral Wind Limits The Accuracy Of Ionospheric Modeling And Forecasting, Michael David, Jan J. Sojka, Robert W. Schunk

Publications

One of the most important input fields for an ionospheric model is the horizontal neutral wind. The primary mechanism by which the neutral wind affects ionospheric densities is the inducement of an upward or downward ion drift along the magnetic field lines; this affects the rate at which ions are lost through recombination. The magnitude of this effect depends upon the dip angle of the magnetic field; for this reason, the impact of the neutral wind is somewhat less in polar regions than at mid-latitudes. It is unfortunate that observations of the neutral wind are relatively scarce, as compared for …

Post-Tensioned Box Girder Bridge An Analysis Approach Using Equivalent Loads, Jen-Kan Kent Hsiao, Alexander Y. Jiang

Publications

Continuous-span, cast-in-place box girders have been popular in modern bridge construction. Secondary moments due to prestressing in continuous-span, post-tensioned girders, however, have significantly complicated the structural analysis and design of the girders. The equivalent load method is a commonly used method in the analysis of continuous-span, post-tensioned concrete girders since the method reduces the analysis of a prestressed structure to that of a nonprestressed structure in which the consideration of secondary moments is not required. The basic concept of the equivalent load method is that the effects of prestressing are replaced by equivalent loads produced by the prestressed tendon along …

Intentional Process For Intentional Space: Higher Education Classroom Spaces For Learning, Taimi Olsen, Stanley Guffey

Publications

This chapter addresses the confluence of theory and practice in developing and using “flexible” classrooms for student learning. A large classroom building renovation will be described, in terms of how collaboration and co-creation of value led to early success of the renovated space. Co-creation of value for staff and faculty can help overcome initial resistance to change, bridge understanding, and drive a successful change from lecture-based teaching to growing use of active learning pedagogies. At the University of Tennessee, Knoxville, co-creation was central to planning, conducting, and sustaining a renovation of space into flexible, technology-enhanced classrooms and changing classroom pedagogy.

Persistent Teaching Practices After Geospatial Technology Professional Development, Lori A. Rubino-Hare, Brooke A. Whitworth, Nena E. Bloom, Jennifer M. Claesgens, Kristi M. Fredrickson, James C. Sample

Publications

This case study described teachers with varying technology skills who were implementing the use of geospatial technology (GST) within project-based instruction (PBI) at varying grade levels and contexts 1 to 2 years following professional development. The sample consisted of 10 fifth- to ninth-grade teachers. Data sources included artifacts, observations, interviews, and a GST performance assessment and were analyzed using a constant comparative approach. Teachers’ teaching actions, beliefs, context, and technology skills were categorized. Results indicated that all of the teachers had high beliefs, but their context and level of technology skills strongly influenced their teaching actions. Two types of teachers …