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Error and optimism bias regularization (open access)

Error and optimism bias regularization

Article describes how in Machine Learning, prediction quality is usually measured using different techniques and evaluation methods. This paper will introduce a simple regularization term to manage the number of over-predicted/under-predicted instances in a regression model.
Date: January 28, 2023
Creator: Sohaee, Nassim
System: The UNT Digital Library
Effect of Polymer Removal on the Morphology and Phase of the Nanoparticles in All-Inorganic Heterostructures Synthesized via Two-Step Polymer Infiltration (open access)

Effect of Polymer Removal on the Morphology and Phase of the Nanoparticles in All-Inorganic Heterostructures Synthesized via Two-Step Polymer Infiltration

This article uses iron oxide/alumina heterostructures formed by two-step infiltration of polystyrene-block-polyvinyl pyridine block copolymer with iron and aluminum precursors from the solution and vapor-phases, respectively, to show that the phase and morphology of iron oxide nanoparticles dramatically depend on the approach used to remove the polymer. The article extends the boundaries of structure manipulations in multicomponent heterostructures synthesized using polymer infiltration synthesis and their properties.
Date: January 28, 2021
Creator: Berman, Diana; Sha, Yuchen & Shevchenko, Elena V.
System: The UNT Digital Library
Molecular characteristics and function of elliptical Kiwifruit (open access)

Molecular characteristics and function of elliptical Kiwifruit

Article describes study analyzing the chemical components of elliptical kiwifruit (Actinidia chinensis Planch) using Fourier transform infrared spectroscopy (FT-IR) and gas chromatography mass spectrometry (GC–MS) technologies.
Date: January 28, 2020
Creator: Hu, Zhe; Ge, Shengbo; Yang, Jun; Li, Yiyang; Bi, Huitao; Zheng, Dongfang et al.
System: The UNT Digital Library
Grain boundary concentration mapping by the CoRaD technique. [Cu--0. 074 to 1. 82 percent U; Count Rate Discriminator (CoRaD)] (open access)

Grain boundary concentration mapping by the CoRaD technique. [Cu--0. 074 to 1. 82 percent U; Count Rate Discriminator (CoRaD)]

Copper and uranium were melted together in an electron beam furnace, rolled and vacuum annealed at 900/sup 0/C. Several samples were examined, varying in uranium content from 0.074 to 1.82 wt. percent. Each sample was mounted in a resin and polished for optical microscope and electron microprobe work. These samples, when viewed under an optical microscope exhibited three distinct phases: featureless grain surfaces, a light gray phase in the grain boundaries, and an occasional dark gray phase also found in the grain boundaries. It is shown that the Count Rate Discriminator technique used in coincidence with a target current detector provides a powerful tool to map and to determine quantitatively the distribution of minor phases in grain boundaries and inclusions. (DLC)
Date: January 28, 1977
Creator: Meisenheimer, R. G. & McCoy, D. D.
System: The UNT Digital Library
POLARIZED HYDROGEN JET TARGET FOR MEASUREMENT OF RHIC PROTON BEAM POLARIZATION. (open access)

POLARIZED HYDROGEN JET TARGET FOR MEASUREMENT OF RHIC PROTON BEAM POLARIZATION.

The performance and unique features of the RHIC polarized jet target and our solutions to the important design constraints imposed on the jet by the RHIC environment are described. The target polarization and thickness were measured to be 0.924 {+-} 2% and 1.3 {+-} 0.2 x 10{sup 12} atoms/cm{sup 2} respectively.
Date: January 28, 2005
Creator: Makdisi, Y.; Wise, T.; Chapman, M.; Graham, D.; Kponou, A.; Mahler, G. et al.
System: The UNT Digital Library
Flor-Essence? Herbal Tonic Promotes Mammary Tumor Development in Sprague Dawley Rats (open access)

Flor-Essence? Herbal Tonic Promotes Mammary Tumor Development in Sprague Dawley Rats

Background: Women who are diagnosed with breast cancer often self-administer complementary and alternative medicines to augment their conventional treatments, improve health, or prevent recurrence. Flor-Essence{reg_sign} Tonic is a complex mixture of herbal extracts used by cancer patients because of anecdotal evidence that it can treat or prevent disease. Methods: Female Sprague Dawley rats were given water or exposed to 3% or 6% Flor-Essence{reg_sign} beginning at one day of age. Mammary tumors were induced with a single oral 40 mg/kg/bw dose of dimethylbenz(a)anthracene at 50 days of age and sacrificed at 23 weeks. Rats were maintained on AIN-76A diet. Results: Control rats had palpable mammary tumor incidence of 51.0% at 19 weeks of age compared to 65.0% and 59.4% for the 3% and 6% Flor-Essence{reg_sign} groups respectively. Overall, no significant difference in time until first palpable tumor was detected among any of the groups. At necropsy, mammary tumor incidence was 82.5% for controls compared to 90.0% and 97.3% for rats consuming 3% and 6% Flor-Essence{reg_sign}, respectively. Mean mammary tumor multiplicity ({+-}SES) for the controls was 2.8 ({+-} 0.5) and statistically different from the 3% or 6% Flor- Essence{reg_sign} groups with 5.2 ({+-} 0.7), and 4.8 ({+-} 0.6), respectively (p{<=}0.01). As expected, …
Date: January 28, 2004
Creator: Bennett, L; Montgomery, J; Steinberg, S & Kulp, K
System: The UNT Digital Library
Using Independent Component Analysis to Separate Signals in Climate Data (open access)

Using Independent Component Analysis to Separate Signals in Climate Data

Global temperature series have contributions from different sources, such as volcanic eruptions and El Nino Southern Oscillation variations. We investigate independent component analysis as a technique to separate unrelated sources present in such series. We first use artificial data, with known independent components, to study the conditions under which ICA can separate the individual sources. We then illustrate the method with climate data from the National Centers for Environmental Prediction.
Date: January 28, 2003
Creator: Fodor, I K & Kamath, C
System: The UNT Digital Library
Water at a hydrophilic solid surface probed by ab-initio molecular dynamics: inhomogeneous thin layers of dense fluid (open access)

Water at a hydrophilic solid surface probed by ab-initio molecular dynamics: inhomogeneous thin layers of dense fluid

We present a microscopic model of the interface between liquid water and a hydrophilic, solid surface, as obtained from ab-initio molecular dynamics simulations. In particular, we focused on the (100)surface of cubic SiC, a leading candidate semiconductor for bio-compatible devices. Our results show that, in the liquid in contact with the clean substrate, molecular dissociation occurs in a manner unexpectedly similar to that observed in the gas phase. After full hydroxylation takes place, the formation of a thin ({approx}3 {angstrom})interfacial layer is observed, which has higher density than bulk water and forms stable hydrogen bonds with the substrate. The liquid does not uniformly wet the surface, rather molecules preferably bind along directions parallel to the Si dimer rows. Our calculations also predict that one dimensional confinement between two hydrophilic surfaces at about 1.3 nm distance does not affect the structural and electronic properties of the whole water sample.
Date: January 28, 2005
Creator: Cicero, G; Grossman, J; Galli, G & Catellani, A
System: The UNT Digital Library
Neutron Skyshine Considerations For The NIF Shielding Design (open access)

Neutron Skyshine Considerations For The NIF Shielding Design

A series of coupled neutron-photon transport Monte-Carlo calculations was performed to estimate the roof shielding required to limit the skyshine dose to less than 1 mrem/y at the site boundary when conducting DT experiments with annual fusion yields up to 1200 MJ (4.2E20 neutrons/y). The NIF shielding design consists of many different components. The basic components include 10-cm-thick Al chamber with 40-cm-thick target chamber gunite shield having multiple penetrations, 1.83-m-thick concrete Target Bay walls, 1.37-m-thick concrete roof, and multiple concrete floors with numerous penetrations. Under this shielding configuration, the skyshine dose at the nearest site-boundary was calculated to be less than 0.2 mrem/y for all possible target illumination configurations. The potential dose at the site boundary would be about one-tenth of the cosmic neutron dose that we measured with bubble neutron detectors on board a commercial roundtrip flight from SF to Rochester. This incremental dose increase is well within the normal fluctuations (noise) of the natural background radiation in the Livermore area. The skyshine dose has no impact on the public. The skyshine dose trends at ground and elevated levels are plotted as a function of distance from 20 m to 1000 m from the center of the target bay. …
Date: January 28, 2004
Creator: Singh, M S; Mecozzi, J M & Tobin, M T
System: The UNT Digital Library
Measurement of the Analyzing Power in PP Elastic Scattering in the Peak CNI Region at RHIC (open access)

Measurement of the Analyzing Power in PP Elastic Scattering in the Peak CNI Region at RHIC

The analyzing power A{sub N} for pp elastic scattering is expected to reach a peak value of 0.045 in the Coulomb Nuclear Interference (CNI) region at a momentum transfer -t of 0.003 (GeV/c){sup 2}. During the 2004 RHIC Run, we completed a measurement of A{sub N} in the CNI region by detecting the recoil protons from pp elastic scattering using a polarized atomic hydrogen gas jet target and the 100 GeV RHIC proton beam. We report the first measurements of the A{sub N} absolute value and shape in the -t range from 0.0015 to 0.010 (GeV/c){sup 2} with a precision better than 0.005 for each A{sub N} data point. The recoil protons were detected with two arrays of Si detectors. The absolute target polarization as monitored by a Breit-Rabi polarimeter was stable at 0.924 {+-} 0.018. This result allows us to further investigate the spin dependence of elastic pp scattering in the very low -t region.
Date: January 28, 2005
Creator: Makdisi, Y.; Okada, H.; Alekseev, I. G.; Bravar, A.; Bunce, G. & AL, ET
System: The UNT Digital Library
Towards SiC Surface Functionalization: An Ab Initio Study (open access)

Towards SiC Surface Functionalization: An Ab Initio Study

We present a microscopic model of the interaction and adsorption mechanism of simple organic molecules on SiC surfaces as obtained from ab initio molecular dynamics simulations. Our results open the way to functionalization of silicon carbide, a leading candidate material for bio-compatible devices.
Date: January 28, 2005
Creator: Cicero, G & Catellani, A
System: The UNT Digital Library
Probability Density Function for Waves Propagating in a Straight Rough Wall Tunnel (open access)

Probability Density Function for Waves Propagating in a Straight Rough Wall Tunnel

The radio channel places fundamental limitations on the performance of wireless communication systems in tunnels and caves. The transmission path between the transmitter and receiver can vary from a simple direct line of sight to one that is severely obstructed by rough walls and corners. Unlike wired channels that are stationary and predictable, radio channels can be extremely random and difficult to analyze. In fact, modeling the radio channel has historically been one of the more challenging parts of any radio system design; this is often done using statistical methods. The mechanisms behind electromagnetic wave propagation are diverse, but can generally be attributed to reflection, diffraction, and scattering. Because of the multiple reflections from rough walls, the electromagnetic waves travel along different paths of varying lengths. The interactions between these waves cause multipath fading at any location, and the strengths of the waves decrease as the distance between the transmitter and receiver increases. As a consequence of the central limit theorem, the received signals are approximately Gaussian random process. This means that the field propagating in a cave or tunnel is typically a complex-valued Gaussian random process.
Date: January 28, 2004
Creator: Pao, Hsueh-Yuan
System: The UNT Digital Library
Applications of Sensitivity Analysis to Uncertainty Quantification in Variably Saturated Flow (open access)

Applications of Sensitivity Analysis to Uncertainty Quantification in Variably Saturated Flow

In this paper, we present results demonstrating the effectiveness of a sensitivity analysis approach to uncertainty quantification of a variably saturated flow model. The basis for our method is a software system which simultaneously solves for solutions of large-scale nonlinear systems of equations and the sensitivity of the solutions to selected parameters. We present test cases showing the effects on the relative uncertainty of pressure due to heterogeneity in the absolute permeability and to differences in parameterizing the Van Genuchten curve soil parameters, {alpha} and n.
Date: January 28, 2002
Creator: Woodward, C; Grant, K E & Maxwell, R
System: The UNT Digital Library
rVISTA 2.0: Evolutionary Analysis of Transcription Factor Binding Sites (open access)

rVISTA 2.0: Evolutionary Analysis of Transcription Factor Binding Sites

Identifying and characterizing the patterns of DNA cis-regulatory modules represents a challenge that has the potential to reveal the regulatory language the genome uses to dictate transcriptional dynamics. Several studies have demonstrated that regulatory modules are under positive selection and therefore are often conserved between related species. Using this evolutionary principle we have created a comparative tool, rVISTA, for analyzing the regulatory potential of noncoding sequences. The rVISTA tool combines transcription factor binding site (TFBS) predictions, sequence comparisons and cluster analysis to identify noncoding DNA regions that are highly conserved and present in a specific configuration within an alignment. Here we present the newly developed version 2.0 of the rVISTA tool that can process alignments generated by both zPicture and PipMaker alignment programs or use pre-computed pairwise alignments of seven vertebrate genomes available from the ECR Browser. The rVISTA web server is closely interconnected with the TRANSFAC database, allowing users to either search for matrices present in the TRANSFAC library collection or search for user-defined consensus sequences. rVISTA tool is publicly available at http://rvista.dcode.org/.
Date: January 28, 2004
Creator: Loots, G G & Ovcharenko, I
System: The UNT Digital Library
On Attaching a Wire to a Triangulated Surface (open access)

On Attaching a Wire to a Triangulated Surface

There have been many papers that have focused on the attachment of wires to surfaces. The focus of this paper will be on wires connected to arbitrarily shaped surfaces, a body that may be modeled with triangles as described in [1]. The basis function for the wire-to-surface junction is constructed by building the 1/r variation of the surface current near the junction into the surface current. In the following we summarize junction bases as currently used. In the presentation we consider their numerical implementation, examine alternative formulations, and review validation studies that prove the approach is robust with respect to wire orientation and surface geometry at the junction.
Date: January 28, 2002
Creator: Champagne, N J; Johnson, W A & Wilton, D R
System: The UNT Digital Library
ATOMIC BEAM STUDIES IN THE RHIC H-JET POLARIMETER. (open access)

ATOMIC BEAM STUDIES IN THE RHIC H-JET POLARIMETER.

The results of atomic beam production studies are presented. Improved cooling of the atoms before jet formation in the dissociator cold nozzle apparently reduces the atomic beam velocity spread and improves beam focusing conditions. A carefully designed sextupole separating (and focusing) magnet system takes advantage of the high brightness source. As a result a record beam intensity of a 12.4 {center_dot} 10{sup 16} atoms/s was obtained within 10 mm acceptance at the collision point. The results of the polarization dilution factor measurements (by the hydrogen molecules at the collision point) are also presented.
Date: January 28, 2005
Creator: Makdisi, Y.; Zelenski, A.; Graham, D.; Kokhanovski, S.; Mahler, G.; Nass, A. et al.
System: The UNT Digital Library
Direct Conversion of Carbon Fuels in a Molten Carbonate Fuel Cell (open access)

Direct Conversion of Carbon Fuels in a Molten Carbonate Fuel Cell

Anodes of elemental carbon may be discharged in a galvanic cell using a molten carbonate electrolyte, a nickel-foam anode-current collector, and a porous nickel air cathode to achieve power densities of 40-100 mW/cm{sup 2}. We report cell and anode polarization, surface area, primary particle size and a crystallization index for nine particulate carbon samples derived from fuel oil, methane, coal, charred biological material and petroleum coke. At 800 C, current densities of 50-125 mA/cm{sup 2} were measured at a representative cell voltage of 0.8 V. Power densities for cells with two carbon-anode materials were found to be nearly the same on scales of 2.8- and 60 cm{sup 2} active area. Constant current operation of a small cell was accompanied by constant voltage during multiple tests of 10-30 hour duration. Cell voltage fell off after the carbon inventory was consumed. Three different cathode structures are compared, indicating that an LLNL fabricated porous nickel electrode with <10 {micro}m pores provides improved rates compared with nickel foam with 100-300 {micro}m pores. Petroleum coke containing substantial sulfur and ash discharges at a slightly lower rate than purified petroleum coke. The sulfur leads to degradation of the anode current collector over time. A conceptual model …
Date: January 28, 2004
Creator: Cherepy, N. J.; Fiet, K. J.; Krueger, R.; Jankowski, Alan Frederic & Cooper, J. F.
System: The UNT Digital Library
TRANSVERSE SPIN AT PHENIX AND FUTURE PLANS. (open access)

TRANSVERSE SPIN AT PHENIX AND FUTURE PLANS.

The PHENIX experiment took data with transversely polarized proton beams in 2001-2002 and measured the transverse single spin asymmetries in inclusive neutral pion and non-identified charge hadrons at midrapidity and {radical} s = 200 GeV. The data near X{sub F} {approx} 0 cover a transverse momentum range from 0.5 to 5.0 GeV/c. The observed asymmetries are consistent with zero with good statistical accuracy. This paper presents the current work in light of earlier measurements at lower energies in this kinematic region and the future plans of the PHENIX detector.
Date: January 28, 2005
Creator: MAKDISI,Y. (FOR THE PHENIX COLLABORATION)
System: The UNT Digital Library
General, Closed-Form Expressions for the Time-Domain Surface Impedances of a Homogeneous, Lossy Half-Space (open access)

General, Closed-Form Expressions for the Time-Domain Surface Impedances of a Homogeneous, Lossy Half-Space

The radio channel places fundamental limitations on the performance of wireless communication systems in tunnels and caves. The transmission path between the transmitter and receiver can vary from a simple direct line of sight to one that is severely obstructed by rough walls and corners. Unlike wired channels that are stationary and predictable, radio channels can be extremely random and difficult to analyze. In fact, modeling the radio channel has historically been one of the more challenging parts of any radio system design; this is often done using statistical methods. The mechanisms behind electromagnetic wave propagation are diverse, but can generally be attributed to reflection, diffraction, and scattering. Because of the multiple reflections from rough walls, the electromagnetic waves travel along different paths of varying lengths. The interactions between these waves cause multipath fading at any location, and the strengths of the waves decrease as the distance between the transmitter and receiver increases. As a consequence of the central limit theorem, the received signals are approximately Gaussian random process. This means that the field propagating in a cave or tunnel is typically a complex-valued Gaussian random process.
Date: January 28, 2004
Creator: Pao, H; Zhu, Z & Dvorak, S L
System: The UNT Digital Library
Wairakite: A Potential Indicator of Fluid Mixing (open access)

Wairakite: A Potential Indicator of Fluid Mixing

Wairakite is a common geothermal mineral. Detailed paragenetic studies indicate that wairakite typically forms after the deposition of epidote {plus_minus} prehnite and later anhydrite + calcite. Epidote and prehnite are interpreted as products of early, high temperature alteration associated with upswelling reservoir fluids whereas calcite and anhydrite are related to descending acidic condensates. Calculated stability relationships among the calc silicate minerals indicates that cooling and/or decreasing pH will lead to the deposition of wairakite instead of epidote, whereas decreasing pH favors wairakite over prehnite. We infer, from the petrographic relationships, that these changes occur when descending condensate mixes with the in-situ reservoir fluids during the waning stages of geothermal activity. Fluid inclusion measurements indicate wairakite is commonly deposited between temperatures of {approx}235 and 300 C.
Date: January 28, 2005
Creator: Moore, J; Bruton, C & Powell, T
System: The UNT Digital Library
A Dynamically Adaptive Arbitrary Lagrangian-Eulerian Method for Hydrodynamics (open access)

A Dynamically Adaptive Arbitrary Lagrangian-Eulerian Method for Hydrodynamics

A new method that combines staggered grid Arbitrary Lagrangian-Eulerian (ALE) techniques with structured local adaptive mesh refinement (AMR) has been developed for solution of the Euler equations. The novel components of the combined ALE-AMR method hinge upon the integration of traditional AMR techniques with both staggered grid Lagrangian operators as well as elliptic relaxation operators on moving, deforming mesh hierarchies. Numerical examples demonstrate the utility of the method in performing detailed three-dimensional shock-driven instability calculations.
Date: January 28, 2004
Creator: Anderson, R W; Pember, R B & Elliott, N S
System: The UNT Digital Library
ATOMIC BEAM POLARIZATION MEASUREMENT OF THE RHIC POLARIZED H-JET TARGET. (open access)

ATOMIC BEAM POLARIZATION MEASUREMENT OF THE RHIC POLARIZED H-JET TARGET.

The RHIC polarized H-Jet measures the polarization of the RHIC proton beam via elastic scattering off a nuclear polarized atomic hydrogen beam. The atomic beam is produced by a dissociator, a beam forming system and sextupole magnets. Nuclear polarization is achieved by exchanging occupation numbers of hyperfine states using high frequency transitions. The polarization was measured using a modified form of a Breit-Rabi polarimeter including focusing magnets and another set of high frequency transitions. The sampling of a large part of the beam and low noise electronics made it possible to measure the polarization to a high degree of accuracy in a very short time period (1 min). Using this system, we measured no depolarization of the atomic beam due to the RF fields of the bunched proton beam. Time-of-Flight measurements were done using a fast chopper and a QMA at the position of the RHIC interaction point to determine the areal density of the atomic beam seen by the RHIC beam.
Date: January 28, 2005
Creator: Makdisi, Y.; Nass, A.; Graham, D.; Kponou, A.; Mahler, G.; Meng, W. et al.
System: The UNT Digital Library
NIF Final Optics System: Frequency Conversion and Beam Conditioning (open access)

NIF Final Optics System: Frequency Conversion and Beam Conditioning

Installation and commissioning of the first of forty-eight Final Optics Assemblies on the National Ignition Facility was completed this past year. This activity culminated in the delivery of first light to a target. The final optics design is described and selected results from first-article commissioning and performance tests are presented.
Date: January 28, 2004
Creator: Wegner, P.; Auerbach, J.; Biesiada, T.; Dixit, S.; Lawson, J.; Menapace, J. et al.
System: The UNT Digital Library
The "Nuclear Car Wash": A Scanner to Detect Illicit Special Nuclear Material in Cargo Containers (open access)

The "Nuclear Car Wash": A Scanner to Detect Illicit Special Nuclear Material in Cargo Containers

There is an urgent need to improve the reliability of screening cargo containers for illicit nuclear material that may be hidden there for terrorist purposes. A screening system is described for detection of fissionable material hidden in maritime cargo containers. The system makes use of a low intensity neutron beam for producing fission; and the detection of the abundant high-energy {gamma} rays emitted in the {beta}-decay of short-lived fission products and {beta}-delayed neutrons. The abundance of the delayed {gamma} rays is almost an order of magnitude larger than that of the delayed neutrons normally used to detect fission and they are emitted on about the same time scale as the delayed neutrons, i.e., {approx}1 min. The energy and temporal distributions of the delayed {gamma} rays provide a unique signature of fission. Because of their high energy, these delayed {gamma} rays penetrate low-Z cargoes much more readily than the delayed neutrons. Coupled with their higher abundance, the signal from the delayed {gamma} rays escaping from the container is predicted to be as much as six decades more intense than the delayed neutron signal, depending upon the type and thickness of the intervening cargo. The {gamma} rays are detected in a large …
Date: January 28, 2004
Creator: Slaughter, D. R.; Accatino, M. R.; Bernstein, A.; Dougan, A. D.; Hall, J. M.; Loshak, A. et al.
System: The UNT Digital Library