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Penalized Nonparametric Scalar-On-Function Regression Via Principal Coordinates, Philip T. Reiss, David L. Miller, Pei-Shien Wu, Wen-Yu Hua 2016 New York University School of Medicine

Penalized Nonparametric Scalar-On-Function Regression Via Principal Coordinates, Philip T. Reiss, David L. Miller, Pei-Shien Wu, Wen-Yu Hua

Philip T. Reiss

A number of classical approaches to nonparametric regression have recently been extended to the case of functional predictors. This paper introduces a new method of this type, which extends intermediate-rank penalized smoothing to scalar-on-function regression. The core idea is to regress the response on leading principal coordinates defined by a relevant distance among the functional predictors, while applying a ridge penalty. Our publicly available implementation, based on generalized additive modeling software, allows for fast optimal tuning parameter selection and for extensions to multiple functional predictors, exponential family-valued responses, and mixed-effects models. In an application to signature verification data, the proposed ...


Multilevel Models For Longitudinal Data, Aastha Khatiwada 2016 East Tennessee State University

Multilevel Models For Longitudinal Data, Aastha Khatiwada

Electronic Theses and Dissertations

Longitudinal data arise when individuals are measured several times during an ob- servation period and thus the data for each individual are not independent. There are several ways of analyzing longitudinal data when different treatments are com- pared. Multilevel models are used to analyze data that are clustered in some way. In this work, multilevel models are used to analyze longitudinal data from a case study. Results from other more commonly used methods are compared to multilevel models. Also, comparison in output between two software, SAS and R, is done. Finally a method consisting of fitting individual models for each ...


The Influence Of The Electric Supply Industry On Economic Growth In Less Developed Countries, Edward Richard Bee 2016 University of Southern Mississippi

The Influence Of The Electric Supply Industry On Economic Growth In Less Developed Countries, Edward Richard Bee

Dissertations

This study measures the impact that electrical outages have on manufacturing production in 135 less developed countries using stochastic frontier analysis and data from World Bank’s Investment Climate surveys. Outages of electricity, for firms with and without backup power sources, are the most frequently cited constraint on manufacturing growth in these surveys.

Outages are shown to reduce output below the production frontier by almost five percent in Africa and by a lower percentage in South Asia, Southeast Asia and the Middle East and North Africa. Production response to outages is quadratic in form. Outages also increase labor cost, reduce ...


The Next Linear Collider Test Accelerator, R. D. Ruth, C. Adolphsen, K. Bane, R. F. Boyce, D. L. Burke, R. Calin, G. Caryotakis, R. Cassel, Stephen L. Clark, H. Deruyter, K. Fant, R. Fuller, S. Heifets, H. Hoag, R. Humphrey, S. Kheifets, R. Koontz, N. M. Kroll, R. T. Lavine, G. A. Loew, A. Menegat, R. H. Miller, C. Nantista, J. M. Patterson, C. Pearson, R. Phillips, J. Rifkin, J. Spencer, S. Tantawi, K. A. Thompson, A. Vlieks, V. Vylet, J. W. Wang, P. B. Wilson, A. Yeremian, B. Youngman 2016 Missouri University of Science and Technology

The Next Linear Collider Test Accelerator, R. D. Ruth, C. Adolphsen, K. Bane, R. F. Boyce, D. L. Burke, R. Calin, G. Caryotakis, R. Cassel, Stephen L. Clark, H. Deruyter, K. Fant, R. Fuller, S. Heifets, H. Hoag, R. Humphrey, S. Kheifets, R. Koontz, N. M. Kroll, R. T. Lavine, G. A. Loew, A. Menegat, R. H. Miller, C. Nantista, J. M. Patterson, C. Pearson, R. Phillips, J. Rifkin, J. Spencer, S. Tantawi, K. A. Thompson, A. Vlieks, V. Vylet, J. W. Wang, P. B. Wilson, A. Yeremian, B. Youngman

Stephen L. Clark

During the past several years, there has been tremendous progress on the development of the RF system and accelerating structures for a Next Linear Collider (NLC). Developments include high-power klystrons, RF pulse compression systems and damped/detuned accelerator structures to reduce wakefields. In order to integrate these separate development efforts into an actual X-band accelerator capable of accelerating the electron beams necessary for an NLC, we are building an NLC Test Accelerator (NLCTA). The goal of the NLCTA is to bring together all elements of the entire accelerating system by constructing and reliably operating an engineered model of a high-gradient ...


Tid And See Testing Results Of Altera Cyclone Field Programmable Gate Array, Stephen L. Clark, K. Avery, R. Parker 2016 Missouri University of Science and Technology

Tid And See Testing Results Of Altera Cyclone Field Programmable Gate Array, Stephen L. Clark, K. Avery, R. Parker

Stephen L. Clark

Total ionizing dose (TID) and single event effects testing was performed on Altera Cyclone FPGAs. The devices exhibit slight performance degradation to a TID of 1 Mrad (Si), but also exhibited single event latchup at a low LET.


On Self-Adjoint And J-Self-Adjoint Dirac-Type Operators: A Case Study, Stephen L. Clark, Fritz Gesztesy 2016 Missouri University of Science and Technology

On Self-Adjoint And J-Self-Adjoint Dirac-Type Operators: A Case Study, Stephen L. Clark, Fritz Gesztesy

Stephen L. Clark

We provide a comparative treatment of some aspects of spectral theory for self-adjoint and non-self-adjoint (but J-self-adjoint) Dirac-type operators connected with the defocusing and focusing nonlinear Schrödinger equation, of relevance to nonlinear optics. In addition to a study of Dirac and Hamiltonian systems, we also introduce the concept of Weyl-Titchmarsh half-line m-coefficients (and 2 × 2 matrix-valued M-matrices) in the non-self-adjoint context and derive some of their basic properties. We conclude with an illustrative example showing that crossing spectral arcs in the non-self-adjoint context imply the blowup of the norm of spectral projections in the limit where the crossing point is ...


Elimination Of Supply Harmonics, Stephen L. Clark, P. Famouri, W. L. Cooley 2016 Missouri University of Science and Technology

Elimination Of Supply Harmonics, Stephen L. Clark, P. Famouri, W. L. Cooley

Stephen L. Clark

The price of the extensive use of power electronic devices is becoming clear: increasing harmonic "pollution." The greater amount of harmonics being introduced into power distribution systems is of concern to both power consumers and power companies. First, a brief look is taken at background information which describes harmonic sources, effects, and characteristics. Then the evolution of the harmonics elimination approaches of current compensation and active filtering are discussed to give some insight into the directions that research is taking.


Elimination Of Supply Harmonics: An Evolution Of Current Compensation And Active Filtering Methods, Stephen L. Clark, P. Famouri, W. L. Cooley 2016 Missouri University of Science and Technology

Elimination Of Supply Harmonics: An Evolution Of Current Compensation And Active Filtering Methods, Stephen L. Clark, P. Famouri, W. L. Cooley

Stephen L. Clark

The price of the extensive use of power electronic devices is becoming clear: increasing harmonic "pollution." This survey takes a brief look at background information related to harmonics, including their sources, effects, and characteristics. Then, the evolution of the harmonics elimination approaches of current compensation and active filtering, which are becoming more feasible due to research and technological improvements, are discussed in order to give some insight into the directions that research is taking.


Retention Of Mothers And Infants In The Prevention Of Mother-To-Child Transmission Of Hiv Programme Is Associated With Individual And Facility-Level Factors In Rwanda., Godfrey B Woelk, Dieudonne Ndatimana, Sally Behan, Martha Mukaminega, Epiphanie Nyirabahizi, Heather J. Hoffman, Placidie Mugwaneza, Muhayimpundu Ribakare, Anouk Amzel, B Ryan Phelps 2016 George Washington University

Retention Of Mothers And Infants In The Prevention Of Mother-To-Child Transmission Of Hiv Programme Is Associated With Individual And Facility-Level Factors In Rwanda., Godfrey B Woelk, Dieudonne Ndatimana, Sally Behan, Martha Mukaminega, Epiphanie Nyirabahizi, Heather J. Hoffman, Placidie Mugwaneza, Muhayimpundu Ribakare, Anouk Amzel, B Ryan Phelps

Epidemiology and Biostatistics Faculty Publications

OBJECTIVES: Investigate levels of retention at specified time periods along the prevention of mother-to-child transmission (PMTCT) cascade among mother-infant pairs as well as individual- and facility-level factors associated with retention.

METHODS: A retrospective cohort of HIV-positive pregnant women and their infants attending five health centres from November 2010 to February 2012 in the Option B programme in Rwanda was established. Data were collected from several health registers and patient follow-up files. Additionally, informant interviews were conducted to ascertain health facility characteristics. Generalized estimating equation methods and modelling were utilized to estimate the number of mothers attending each antenatal care visit ...


Potato Cultivar Differences Associated With Mealiness, Diane R. McComber, Harry T. Horner, Mark A. Chamberlin, David F. Cox 2016 Iowa State University

Potato Cultivar Differences Associated With Mealiness, Diane R. Mccomber, Harry T. Horner, Mark A. Chamberlin, David F. Cox

Harry Horner

Russet Burbank, Norchip, Pontiac, and LaSoda potato cultivars were examined for the parameters mealy and waxy. Russet Burbank was judged dry, hard and particulate, typifying mealiness. Using phase contrast microscopy and scanning electron microscopy, raw mealy cells were determined to be larger and more irregularly shaped than cells from waxy cultivars. Mealy cooked cells were engorged with gelatinized starch, cell walls were more polarized, and cell shapes were better retained after mashing, when compared to waxy cells. NMR-T2 bound water readings from Russet Burbank and Pontiac samples did not differ from each other. Starch granule sizes and shapes varied by ...


A Microscopic Study Of The Trichomes On Gynoecia Of Normal And Tetraploid Clark Cultivars Of Glycine Max And Seven Near Isogenic Lines, Rosaria A. Healy, Harry T. Horner, Theodore B. Bailey, Reid G. Palmer 2016 Iowa State University

A Microscopic Study Of The Trichomes On Gynoecia Of Normal And Tetraploid Clark Cultivars Of Glycine Max And Seven Near Isogenic Lines, Rosaria A. Healy, Harry T. Horner, Theodore B. Bailey, Reid G. Palmer

Harry Horner

The surfaces of gynoecia of Glycine max cultivars—normal Clark, a tetraploid Clark, and seven isolines—display variations in at least three types of trichomes. The normal Clark soybean gynoecium has at least three and possibly four types of trichomes: a two‐ to four‐celled, elongate, thick‐walled trichome (TWT), an elongate thin‐walled unicellular trichome (UCT), a secretory multicellular trichome (MCT), and an elongate thin‐walled bicellular trichome that we have interpreted as an immature TWT. All these types are present on the gynoecium by 1 d before anthesis. After fertilization, the UCT is rare, but the other types ...


Physiologic Effects Of Nasopharyngeal Administration Of Supplemental Oxygen At Various Flow Rates In Healthy Neonatal Foals, David M. Wong, Cody J. Alcott, Chong Wang, Bonnie L. Hay-Kraus, Benjamin R. Buchanan, Charles W. Brockus 2016 Iowa State University

Physiologic Effects Of Nasopharyngeal Administration Of Supplemental Oxygen At Various Flow Rates In Healthy Neonatal Foals, David M. Wong, Cody J. Alcott, Chong Wang, Bonnie L. Hay-Kraus, Benjamin R. Buchanan, Charles W. Brockus

Chong Wang

Objective—To evaluate the effects of various flow rates of oxygen administered via 1 or 2 nasal cannulae on the fraction of inspired oxygen concentration (Fio2) and other arterial blood gas variables in healthy neonatal foals.

Animals—9 healthy neonatal (3- to 4-day-old) foals.

Procedures—In each foal, a nasal cannula was introduced into each naris and passed into the nasopharynx to the level of the medial canthus of each eye; oxygen was administered at 4 flow rates through either 1 or both cannulae (8 treatments/foal). Intratracheal Fio2, intratracheal end-tidal partial pressure of carbon dioxide, and arterial ...


A Live-Attenuated And An Inactivated Chimeric Porcine Circovirus (Pcv)1-2 Vaccine Are Both Effective At Inducing A Humoral Immune Response And Reducing Pcv2 Viremia And Intrauterine Infection In Female Swine Of Breeding Age, Michelle Hemann, Nathan M. Beach, Xiang-Jin Meng, Chong Wang, Patrick G. Halbur, Tanja Opriessnig 2016 Iowa State University

A Live-Attenuated And An Inactivated Chimeric Porcine Circovirus (Pcv)1-2 Vaccine Are Both Effective At Inducing A Humoral Immune Response And Reducing Pcv2 Viremia And Intrauterine Infection In Female Swine Of Breeding Age, Michelle Hemann, Nathan M. Beach, Xiang-Jin Meng, Chong Wang, Patrick G. Halbur, Tanja Opriessnig

Chong Wang

The objective of this pilot study was to determine the efficacy of inactivated (1 or 2 dose) and live-attenuated chimeric porcine circovirus (PCV)1-2 vaccines in sows using the PCV2-spiked semen model. Thirty-five sows were randomly divided into 6 groups: negative and positive controls, 1 dose inactivated PCV1-2 vaccine challenged (1-VAC-PCV2), 2 dose inactivated PCV1-2 vaccine challenged (2-VAC-PCV2), 1 dose live-attenuated PCV1-2 vaccine unchallenged (1-LIVE-VAC), and 1 dose live-attenuated PCV1-2 vaccine challenged (1-LIVE-VAC-PCV2). The inactivated PCV1-2 vaccine induced higher levels of PCV2-specific antibodies in dams. All vaccination strategies provided good protection against PCV2 viremia in dams, whereas the majority of ...


Bacterial Isolates, Antimicrobial Susceptibility Patterns, And Factors Associated With Infection And Outcome In Foals With Septic Arthritis: 83 Cases (1998–2013), Kate L. Hepworth-Warren, David M. Wong, Caroline V. Fulkerson, Chong Wang, Yaxuan Sun 2016 Iowa State University

Bacterial Isolates, Antimicrobial Susceptibility Patterns, And Factors Associated With Infection And Outcome In Foals With Septic Arthritis: 83 Cases (1998–2013), Kate L. Hepworth-Warren, David M. Wong, Caroline V. Fulkerson, Chong Wang, Yaxuan Sun

Chong Wang

Objective—To determine clinical characteristics, clinicopathologic data, and bacterial culture and antimicrobial susceptibility results associated with septic arthritis in foals ≤ 180 days old.

Design—Retrospective case series.

Animals—83 foals with septic arthritis.

Procedures—Medical records at 2 teaching hospitals between 1998 and 2013 were searched to identify those for foals ≤ 180 days old with confirmed infection of ≥ 1 synovial structure. Data extracted from the records included signalment, clinicopathologic information, bacteriologic culture and antimicrobial susceptibility results, and outcome. Data were analyzed for all foals as a single population and for foals stratified into 3 age groups (≤ 7 days, 8 to ...


Effect Of Cold Compression Therapy On Postoperative Pain, Swelling, Range Of Motion, And Lameness After Tibial Plateau Leveling Osteotomy In Dogs, Kevin A. Drygas, Scott R. McClure, Robert L. Goring, Antonio Pozzi, Sheilah A. Robertson, Chong Wang 2016 Affiliated Veterinary Specialists

Effect Of Cold Compression Therapy On Postoperative Pain, Swelling, Range Of Motion, And Lameness After Tibial Plateau Leveling Osteotomy In Dogs, Kevin A. Drygas, Scott R. Mcclure, Robert L. Goring, Antonio Pozzi, Sheilah A. Robertson, Chong Wang

Chong Wang

Objective—To evaluate the effect of cold compression therapy (CCT) on postoperative pain, lameness, range of motion of the stifle joint, and swelling following tibial plateau leveling osteotomy (TPLO) in dogs. Design—Randomized, blinded, placebo-controlled clinical trial. Animals—34 client-owned dogs with unilateral deficiency of a cranial cruciate ligament undergoing TPLO. Procedures—Dogs were assigned to 2 groups. Group 1 (n = 17 dogs) received CCT in the 24-hour period following TPLO. Group 2 (n = 17 dogs) received no CCT. Degree of lameness, range of motion, and circumference of the stifle joint were measured before surgery and 1,14, and 28 ...


A Method To Quantify Infectious Airborne Pathogens At Concentrations Below The Threshold Of Quantification By Culture, Timothy D. Cutler, Chong Wang, Steven J. Hoff, Jeffrey J. Zimmerman 2016 Iowa State University

A Method To Quantify Infectious Airborne Pathogens At Concentrations Below The Threshold Of Quantification By Culture, Timothy D. Cutler, Chong Wang, Steven J. Hoff, Jeffrey J. Zimmerman

Chong Wang

In aerobiology, dose-response studies are used to estimate the risk of infection to a susceptible host presented by exposure to a specific dose of an airborne pathogen. In the research setting, host- and pathogen-specific factors that affect the dose-response continuum can be accounted for by experimental design, but the requirement to precisely determine the dose of infectious pathogen to which the host was exposed is often challenging. By definition, quantification of viable airborne pathogens is based on the culture of micro-organisms, but some airborne pathogens are transmissible at concentrations below the threshold of quantification by culture. In this paper we ...


Noise Estimation In Magnitude Mr Datasets, Ranjan Maitra, David Faden 2016 Iowa State University

Noise Estimation In Magnitude Mr Datasets, Ranjan Maitra, David Faden

Ranjan Maitra

Estimating the noise parameter in magnitude magnetic resonance (MR) images is important in a wide range of applications. We propose an automatic noise estimation method that does not rely on a substantial proportion of voxels being from the background. Specifically, we model the magnitude of the observed signal as a mixture of Rice distributions with common noise parameter. The Expectation-Maximization (EM) algorithm is used to estimate the parameters, including the common noise parameter. The algorithm needs initializing values for which we provide some strategies that work well. The number of components in the mixture model also need to be estimated ...


Synthetic Magnetic Resonance Imaging Revisited, Ranjan Maitra, John J. Riddles 2016 Iowa State University

Synthetic Magnetic Resonance Imaging Revisited, Ranjan Maitra, John J. Riddles

Ranjan Maitra

Synthetic magnetic resonance (MR) imaging is an approach suggested in the literature to predict MR images at different design parameter settings from at least three observed MR scans. However, performance is poor when no regularization is used in the estimation and otherwise computationally impractical to implement for three-dimensional imaging methods. We propose a method which accounts for spatial context in MR images by the imposition of a Gaussian Markov Random Field (MRF) structure on a transformation of the spin-lattice relaxation time, the spin-spin relaxation time and the proton density at each voxel. The MRF structure is specified through a Matrix ...


Initializing Partition-Optimization Algorithms, Ranjan Maitra 2016 Iowa State University

Initializing Partition-Optimization Algorithms, Ranjan Maitra

Ranjan Maitra

Clustering data sets is a challenging problem needed in a wide array of applications. Partition-optimization approaches, such as k-means or expectation-maximization (EM) algorithms, are suboptimal and find solutions in the vicinity of their initialization. This paper proposes a staged approach to specifying initial values by finding a large number of local modes and then obtaining representatives from the most separated ones. Results on test experiments are excellent. We also provide a detailed comparative assessment of the suggested algorithm with many commonly used initialization approaches in the literature. Finally, the methodology is applied to two data sets on diurnal microarray gene ...


Social Learning And Adoption Of New Behavior In A Virtual Agent Society, Benjamin D. Nye, Barry G. Silverman 2016 University of Pennsylvania

Social Learning And Adoption Of New Behavior In A Virtual Agent Society, Benjamin D. Nye, Barry G. Silverman

Barry G Silverman

Social learning and adoption of new behavior govern the rise of a variety of behaviors: from actions as mundane as dance steps to those as dangerous as new ways to make IED detonators. However, agents in immersive virtual environments lack the ability to realistically simulate the spread of new behavior. To address this gap, a cognitive model was designed that represents the well-known socio-cognitive factors of attention, social influence, and motivation that influence learning and the adoption of a new behavior. To explore the effectiveness of this model, simulations modeled the spread of two competing memes in Hamariyah, an archetypal ...


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