Digital Commons Network^™

Statistics Of Epidemics In Networks By Passing Messages, Munik Shrestha

Physics & Astronomy ETDs

Epidemic processes are common out-of-equilibrium phenomena of broad interdisciplinary interest. In this thesis, we show how message-passing approach can be a helpful tool for simulating epidemic models in disordered medium like networks, and in particular for estimating the probability that a given node will become infectious at a particular time. The sort of dynamics we consider are stochastic, where randomness can arise from the stochastic events or from the randomness of network structures. As in belief propagation, variables or messages in message-passing approach are defined on the directed edges of a network. However, unlike belief propagation, where the posterior distributions …

Measuring Discharge In Wadeable Streams, Whitney Cole Blackburn-Lynch, Carmen T. Agouridis, Tyler M. Sanderson

Agriculture and Natural Resources Publications

Streams and rivers are plentiful in Kentucky from small mountain brooks to large rivers such as the Mississippi River along the Commonwealth’s western border and the Ohio River along its northern border (Figure 1). Kentucky has more than 90,000 miles of streams and contains more navigable water than any other state except Alaska. These streams provide important ecological services such as transporting water, sediment and nutrients and providing habitats to aquatic organisms such as fish and macroinvertebrates and terrestrial ones such as deer and birds. Streams also provide societal services, including drinking water, transportation and recreation. Careful management of these …

Drought Risk Management For Beef Cattle Farms, Stephen F. Higgins, Lee Moser, Kylie Schmidt

Agriculture and Natural Resources Publications

One of the most challenging aspects of owning and operating any farming operation is dealing with uncertainty. Uncertainty on the farm comes in many forms; livestock health, feed prices, fuel prices, market prices, and weather to name a few. Over the past decade, the prevalence and impact of drought on agriculture has dramatically increased, thus adding further uncertainty to farmers’ decision-making processes. Drought and the associated loss of productivity is a real risk scenario that all farmers must face. With this inherent risk, one must protect their farm and the environment it impacts through a sound decision-making process that factors …

Hydrologic Models, Tyler Mahoney, Carmen T. Agouridis, Richard C. Warner

Agriculture and Natural Resources Publications

Water is a vital part of our everyday lives. Water is necessary for domestic activities such as drinking, cooking and cleaning; agricultural practices such as growing crops and livestock; and industrial uses such as manufacturing and transporting products (Figure 1). Some of our water use is seen, such as when we take a shower. However, most of our water use is hidden, meaning that water was used to make a product although little to no water may be in the product itself. Because water is so important, a branch of science is devoted to its study.

Sediment Fingerprinting, Somsubhra Chattopadhyay, Carmen T. Agouridis, James F. Fox

Agriculture and Natural Resources Publications

Sediment is one of the most common pollutants in waterbodies such as streams, rivers and lakes. Sources of sediment include upland areas, meaning lands above the floodplain, as well as the waterbodies themselves (Figure 1). Human activities that reduce or remove vegetation increase the amount of soil eroded. In the uplands, examples of sediment sources include tilled crop fields, grazed pastures, construction sites, and timber harvesting areas. Along water bodies, the beds and banks erode due to the force of moving water. Streambank erosion, for instance, contributes anywhere from 15 to 90% of the suspended sediment load in streams.

Implementation Of Space-Time Finite Element Formulation In Elastodynamics, Sidharth Ramesh

Graduate Theses - Mechanical Engineering

Elastodynamics is an academic field that is involved in solving problems related to the field of wave propagation in continuous solid medium. Finite element methods have long been an accepted way of solving elastodynamics problems in the spatial dimension. Considerable thought has been given to ways of implementing finite element discretization in the temporal dimension as well. A particular method of finite element solving called space-time finite element formulation is explored in this thesis, which is a relatively recent technique for discretization in spatial and temporal dimensions. The present thesis explores the implementation of the Space-Time finite element formulation in …

Academic Affairs Update, February 2016, University Of Northern Iowa. Office Of The Provost And Executive Vice President For Academic Affairs.

Academic Affairs Update

Inside this issue:

-- Local Students Are Full STE(A)M Ahead
-- Gabriela Olivares Named UNI-NCBI Diversity Fellow
-- Harry Brod Named UNI-NCBI Director

Academics: The Newsletter Of The Swosu College Of Arts And Sciences, Peter Grant

aCAdemicS: The Newsletter of the SWOSU College of Arts & Sciences

No abstract provided.

Neutron And Magnetic Studies Of La₀.₇Sr₀.₃Mn₁₋ₓcrₓo₃(X ≤ 0.7): A Homogeneous Charge-Ordered System, Thomas F. Creel, Jinbo Yang, Satish K. Malik, Sylvio Quezado, Oran Allan Pringle, William B. Yelon, William Joseph James

Physics Faculty Research & Creative Works

Structural and magnetic properties of La_0.7Sr_0.3Mn_1-xCr_xO₃ (0 < x ≤ 0.7) have been studied in order to determine the effect of substitution of Cr³⁺ for Mn³⁺. The data consist of neutron and x-ray powder-diffraction and magnetization measurements. We previously suggested these systems transition from ferromagnetic to antiferromagnetic ordering with the intermediate concentrations containing coexisting ferromagnetic and antiferromagnetic domains. Upon further detailed examination, we find that the neutron data can be fit using a single homogeneous long-range magnetically ordered state and compositionally dependent charge ordering. The magnetic structures are controlled by the competition between Mn-Mn, Mn-Cr, and Cr-Cr interactions (double exchange and superexchange). The metal to …

Histogram Of Oriented Phase And Gradient (Hopg) Descriptor For Improved Pedestrian Detection, Hussin Ragb, Vijayan K. Asari

Electrical and Computer Engineering Faculty Publications

This paper presents a new pedestrian detection descriptor named Histogram of Oriented Phase and Gradient (HOPG) based on a combination of the Histogram of Oriented Phase (HOP) features and the Histogram of Oriented Gradient features (HOG).

The proposed descriptor extracts the image information using both the gradient and phase congruency concepts. Although the HOG based method has been widely used in the human detection systems, it lacks to deal effectively with the images impacted by the illumination variations and cluttered background. By fusing HOP and HOG features, more structural information can be identified and localized in order to obtain more …

A Real-Time Information Based Demand-Side Management System In Smart Grid, Feng Ye, Yi Qian, Rose Qingyang Hu

Electrical and Computer Engineering Faculty Publications

In this paper, we study a real-time information based demand-side management (DSM) system with advanced communication networks in smart grid. DSM can smooth peak-to-average ratio (PAR) of power usage in the grid, which in turn reduces the waste of fuel and the emission of greenhouse gas. We first target to minimize PAR with a centralized scheme. To motivate power suppliers, we further propose another centralized scheme targeting minimum power generation cost. However, customers may not be motivated by a centralized scheme since such a scheme requires total control and privacy from them. A centralized scheme also requires too much real-time …

Physics Colloquium | The Physics Of Sports A Real Science Course For The Nonscience Major, Feb 18, Ohio University College Of Arts & Sciences

All Forum Articles

No abstract provided.

Celebration Of Faculty Scholarship 2015, Olin Library

Celebration of Faculty Scholarship

No abstract provided.

Distinct Encounter Complexes Of Pai-1 With Plasminogen Activators And Vitronectin Revealed By Changes In The Conformation And Dynamics Of The Reactive Center Loop, Tihami Qureshi, Sumit Goswami, Carlee S. Mcclintock, Matthew T. Ramsey, Cynthia B. Peterson

Faculty Publications

© 2015 The Protein Society Plasminogen activator inhibitor-1 (PAI-1) is a biologically important serine protease inhibitor (serpin) that, when overexpressed, is associated with a high risk for cardiovascular disease and cancer metastasis. Several of its ligands, including vitronectin, tissue-type and urokinase-type plasminogen activator (tPA, uPA), affect the fate of PAI-1. Here, we measured changes in the solvent accessibility and dynamics of an important unresolved functional region, the reactive center loop (RCL), upon binding of these ligands. Binding of the catalytically inactive S195A variant of tPA to the RCL causes an increase in fluorescence, indicating greater solvent protection, at its C-terminus, …

Mathematical Model Of The Firefly Luciferase Complementation Assay Reveals A Non-Linear Relationship Between The Detected Luminescence And The Affinity Of The Protein Pair Being Analyzed, Renee Dale, Yuki Ohmuro-Matsuyama, Hiroshi Ueda, Naohiro Kato

Faculty Publications

© 2016 Dale et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. The firefly luciferase complementation assay is widely used as a bioluminescent reporter technology to detect protein-protein interactions in vitro, in cellulo, and in vivo. Upon the interaction of a protein pair, complemented firefly luciferase emits light through the adenylation and oxidation of its substrate, luciferin. Although it has been suggested that kinetics of light production in the firefly luciferase complementation assay …

Balance Of Threat, Balance Of Mind: Nuclear Rivalry And Arms Control, Benjamin Joseph Bonin

Political Science ETDs

Under what conditions will rivals choose to accept mutual constraints, limitations, and even reductions on their capabilities for waging war? Contemporary political science lacks a strong theoretical basis for understanding this behavior, despite the fact that states in the modern era continue to negotiate and enter into arms control arrangements. This study contributes a theoretical framework and empirical analysis identifying the conditions under which nuclear-armed rivals might choose to curb their deadly arsenals. Traditional theories grounded in classical deterrence theory suggest arms control serves to preserve a deterrent status quo and prevent expensive and destabilizing arms competition; it should therefore …

Studies Of Coherent Synchrotron Radiation With The Discontinuous Galerkin Method, David Bizzozero

Mathematics & Statistics ETDs

In this thesis, we present methods for integrating Maxwell's equations in Frenet-Serret coordinates in several settings using discontinuous Galerkin (DG) finite element method codes in 1D, 2D, and 3D. We apply these routines to the study of coherent synchrotron radiation, an important topic in accelerator physics. We build upon the published computational work of T. Agoh and D. Zhou in solving Maxwell's equations in the frequency-domain using a paraxial approximation which reduces Maxwell's equations to a Schrödinger-like system. We also evolve Maxwell's equations in the time-domain using a Fourier series decomposition with 2D DG motivated by an experiment performed at …

Closure Operations On Subgroups, Paige Mankey

Mathematics & Statistics ETDs

During the past five years, a number of mathematicians have conducted research involving closure operations on the ideals of commutative rings. The most accessible paper on this is written by Neil Epstein, entitled "A Guide to Closure Operations in Commutative Algebra". This paper compiles much of the research done on the topic, and gives the reader an overview of closure operations on ideals, and includes examples, methods for constructions, and various special properties that arise from these operations as they pertain to ideals. However, very little research--if any--has been done on closures of subgroups. This thesis aims to give a …

Faculty Senate Monthly Packet February 2016, Portland State University Faculty Senate

Faculty Senate Monthly Packets

The February 2016 Monthly packet includes the February agenda and appendices and the Faculty Senate minutes and attachments from the meeting held January 2016.

Strain Effects On The Work Function Of An Organic Semiconductor, Yanfei Wu, Annabel R. Chew, Geoffrey A. Rojas, Gjergji Sini, Greg Haugstad, Alex Belianinov, Sergei V. Kalinin, Hong Li, Chad Risko, Jean-Luc Brédas, Alberto Salleo, C. Daniel Frisbie

Chemistry Faculty Publications

Establishing fundamental relationships between strain and work function (WF) in organic semiconductors is important not only for understanding electrical properties of organic thin films, which are subject to both intrinsic and extrinsic strains, but also for developing flexible electronic devices. Here we investigate tensile and compressive strain effects on the WF of rubrene single crystals. Mechanical strain induced by thermal expansion mismatch between the substrate and rubrene is quantified by X-ray diffraction. The corresponding WF change is measured by scanning Kelvin probe microscopy. The WF of rubrene increases (decreases) significantly with in-plane tensile (compressive) strain, which agrees qualitatively with density …

Selection And Control Of Individual Domain Walls In Nanowire Arrays Via Asymmetric Depinning Fields, Andrew Kunz, H. Henry Le, Demetrious Kutzke, Jesse Vogeler-Wunsch

Physics Faculty Research and Publications

Artificially inscribed notches are often used to pin domain walls (DWs) in ferromagnetic nanowires. The process of selecting and moving the trapped DW in nanowire arrays is an important step for potential applications. The chirality of a DW leads to a pair of pinning positions at the inscribed notches, which can be modeled by a symmetric double well. The depinning field depends on the side of the well, the DW is trapped with respect to the applied field direction, and the DWs can also be transitioned between the two wells without depinning. We demonstrate how manipulating the double well improves …

Polar Codes In Network Quantum Information Theory, Christoph Hirche, Ciara Morgan, Mark M. Wilde

Faculty Publications

Polar coding is a method for communication over noisy classical channels, which is provably capacity achieving and has an efficient encoding and decoding. Recently, this method has been generalized to the realm of quantum information processing, for tasks such as classical communication, private classical communication, and quantum communication. In this paper, we apply the polar coding method to network classicalquantum information theory, by making use of recent advances for related classical tasks. In particular, we consider problems such as the compound multiple access channel and the quantum interference channel. The main result of our work is that it is possible …

Uniform Localization Is Always Uniform, Rui Han

Faculty Publications

In this note we show that if a family of ergodic Schrödinger operators on l2(ℤγ) with continuous potentials have uniformly localized eigenfunctions, then these eigenfunctions must be uniformly localized in a homogeneous sense.

Measuring Community Resilience To Coastal Hazards Along The Northern Gulf Of Mexico, Nina S.N. Lam, Margaret Reams, Kenan Li, Chi Li, Lillian P. Mata

Faculty Publications

The abundant research examining aspects of social-ecological resilience, vulnerability, and hazards and risk assessment has yielded insights into these concepts and suggested the importance of quantifying them. Quantifying resilience is complicated by several factors including the varying definitions of the term applied in the research, difficulties involved in selecting and aggregating indicators of resilience, and the lack of empirical validation for the indices derived. This paper applies a new model, called the resilience inference measurement (RIM) model, to quantify resilience to climate-related hazards for 52 U.S. counties along the northern Gulf of Mexico. The RIM model uses three elements (exposure, …

Pathological Scattering By A Defect In A Slow-Light Periodic Layered Medium, Stephen P. Shipman, Aaron T. Welters

Faculty Publications

Scattering of electromagnetic fields by a defect layer embedded in a slow-light periodically layered ambient medium exhibits phenomena markedly different from typical scattering problems. In a slow-light periodic medium, constructed by Figotin and Vitebskiy, the energy velocity of a propagating mode in one direction slows to zero, creating a "frozen mode" at a single frequency within a pass band, where the dispersion relation possesses a flat inflection point. The slow-light regime is characterized by a 3 × 3 Jordan block of the log of the 4 × 4 monodromy matrix for EM fields in a periodic medium at special frequency …

Leech Exoplanet Imaging Survey: Characterization Of The Coldest Directly Imaged Exoplanet, Gj 504 B, And Evidence For Super-Stellar Metallicity, Andrew J. Skemer, Caroline V. Morley, Neil T. Zimmerman, Michael F. Skrutskie, Jarron Leisenring, Esther Buenzli, Mickael Bonnefoy, Vanessa Bailey, Philip Hinz, Denis Defrere, Simone Esposito, Daniel Apai, Beth Biller, Wolfgang Brandner, Laird Close, Justin R. Crepp, Robert J. De Rosa, Silvano Desidera, Josh Eisner, Jonathan Fortney, Richard Freedman, Thomas Henning, Karl-Heinz Hofmann, Taisiya Kopytova, Roxana Lupu, Anne-Lise Maire, Jared R. Males, Mark Marley, Katie Morzinski, Apurva Oza, Jenny Patience, Abhijith Rajan, George Rieke, Dieter Schertl, Joshua Schlieder, Jordan Stone, Kate Su, Amali Vaz, Channon Visscher, Kimberly Ward-Duong, Gerd Weigelt, Charles E. Woodward

Faculty Work Comprehensive List

As gas giant planets and brown dwarfs radiate away the residual heat from their formation, they cool through a spectral type transition from L to T, which encompasses the dissipation of cloud opacity and the appearance of strong methane absorption. While there are hundreds of known T-type brown dwarfs, the first generation of directly-imaged exoplanets were all L-type. Recently, Kuzuhara et al. (2013) announced the discovery of GJ 504 b, the first T dwarf exoplanet. GJ 504 b provides a unique opportunity to study the atmosphere of a new type of exoplanet with a ∼500 K temperature that bridges the …

A Ridge-Fed Conical Horn Antenna For Small Satellites, Arjun Gupta

Electrical and Computer Engineering ETDs

The increased popularity of small satellites such as CubeSats as an alternative vehicle for efficient and low cost space exploration has revolutionized the space research industry. The small physical size and other constraints owing to outer space applications has presented a myriad of exciting opportunities for antenna engineers to come up with alternative solutions to meet the ever evolving needs of the CubeSat applications. The advancement of technology has enabled small satellites to carry out sophisticated missions such as space weather monitoring, space telescopes, imaging and relaying of information from distant satellites. Advanced applications require a high speed downlink with …

Design Live Load Factor Calibration For Michigan Highway Bridges, Christopher D. Eamon, Valid Kamjoo, Kazuhiko Shinki

Civil and Environmental Engineering Faculty Research Publications

In this study, a reliability-based calibration of live load factors for bridge design specific to the State of Michigan was conducted. Two years of high frequency WIM data from 20 representative state-wide sites were analyzed, and load effects were generated for bridge spans from 6 to 122 m (20 to 400 ft), considering simple and continuous moments and shears, as well as single lane and two lane effects. Seventy-five year statistics for maximum live load were then estimated with probabilistic projection. Bridge girders considered for the calibration included composite steel, prestressed concrete, side-by-side and spread box beams, as well as …

How To Measure Metallicity From Five-Band Photometry With Supervised Machine Learning Algorithms, Viviana Acquaviva

Publications and Research

We demonstrate that it is possible to measure metallicity from the SDSS five-band photometry to better than 0.1 dex using supervised machine learning algorithms. Using spectroscopic estimates of metallicity as ground truth, we build, optimize and train several estimators to predict metallicity. We use the observed photometry, as well as derived quantities such as stellar mass and photometric redshift, as features, and we build two sample data sets at median redshifts of 0.103 and 0.218 and median r-band magnitude of 17.5 and 18.3, respectively. We find that ensemble methods, such as random forests of trees and extremely randomized trees and …

Wanda: Securely Introducing Mobile Devices (Extended Version), Timothy J. Pierson, Xiaohui Liang, Ronald Peterson, David Kotz

Computer Science Technical Reports

Nearly every setting is increasingly populated with wireless and mobile devices -- whether appliances in a home, medical devices in a health clinic, sensors in an industrial setting, or devices in an office or school. There are three fundamental operations when bringing a new device into any of these settings: (1) to configure the device to join the wireless local-area network, (2) to partner the device with other nearby devices so they can work together, and (3) to configure the device so it connects to the relevant individual or organizational account in the cloud. The challenge is to accomplish all …