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Faculty Publications

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Articles 2401 - 2430 of 3797

Full-Text Articles in Physical Sciences and Mathematics

Accelerating Corpus Annotation Through Active Learning, George Busby, Marc Carmen, James Carroll, Robbie Haertel, Deryle W. Lonsdale, Peter Mcclanahan, Eric K. Ringger, Kevin Seppi Mar 2008

Accelerating Corpus Annotation Through Active Learning, George Busby, Marc Carmen, James Carroll, Robbie Haertel, Deryle W. Lonsdale, Peter Mcclanahan, Eric K. Ringger, Kevin Seppi

Faculty Publications

PDF of Powerpoint Presentation on accelerating corpus annotation through active learning. This presentation was given at the Conference of the American Association for Corpus Linguistics in 2008.

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Analysis Of Canonical Chinese Antonym Co-Occurrence, Eric K. Ringger, Guohui Liu, Shiping Liu, Xingfu Wang Mar 2008

Analysis Of Canonical Chinese Antonym Co-Occurrence, Eric K. Ringger, Guohui Liu, Shiping Liu, Xingfu Wang

Faculty Publications

PDF of Powerpoint Presentation on canonical Chinese antonym co-occurrence. This presentation was given at the Conference of the American Association for Corpus Linguistics in 2008.

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Compiling And Annotating A Syriac Corpus, George Busby, James Carroll, Marc Carmen, Carl Griffin, Robbie Haertel, Kristian Heal, Joshua Heaton, Deryle W. Lonsdale, Peter Mcclanahan, Eric K. Ringger, Kevin Seppi, David Taylor Mar 2008

Compiling And Annotating A Syriac Corpus, George Busby, James Carroll, Marc Carmen, Carl Griffin, Robbie Haertel, Kristian Heal, Joshua Heaton, Deryle W. Lonsdale, Peter Mcclanahan, Eric K. Ringger, Kevin Seppi, David Taylor

Faculty Publications

PDF of Powerpoint Presentation on compiling and annotating a Syriac corpus. This presentation was given at the Conference of the American Association for Corpus Linguistics in 2008.

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Search For Gravitational Waves From Binary Inspirals In S3 And S4 Ligo Data, B. Abbott, R. Abbott, R. Adhikari, J. Agresti, P. Ajith, B. Allen, R. Amin, S. B. Anderson, W. G. Anderson, M. Arain, M. Araya, H. Armandula, M. Ashley, S. Aston, P. Aufmuth, C. Aulbert, S. Babak, S. Ballmer, H. Bantilan, B. C. Barish, C. Barker, D. Barker, B. Barr, P. Barriga, M. A. Barton, K. Bayer, K. Belczynski, J. Betzwieser, P. T. Beyersdorf, B. Bhawal, I. A. Bilenko, Tiffany Z. Summerscales Mar 2008

Search For Gravitational Waves From Binary Inspirals In S3 And S4 Ligo Data, B. Abbott, R. Abbott, R. Adhikari, J. Agresti, P. Ajith, B. Allen, R. Amin, S. B. Anderson, W. G. Anderson, M. Arain, M. Araya, H. Armandula, M. Ashley, S. Aston, P. Aufmuth, C. Aulbert, S. Babak, S. Ballmer, H. Bantilan, B. C. Barish, C. Barker, D. Barker, B. Barr, P. Barriga, M. A. Barton, K. Bayer, K. Belczynski, J. Betzwieser, P. T. Beyersdorf, B. Bhawal, I. A. Bilenko, Tiffany Z. Summerscales

Faculty Publications

We report on a search for gravitational waves from the coalescence of compact binaries during the third and fourth LIGO science runs. The search focused on gravitational waves generated during the inspiral phase of the binary evolution. In our analysis, we considered three categories of compact binary systems, ordered by mass: (i) primordial black hole binaries with masses in the range 0.35M

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Multi-Class Classification Fusion Using Boosting For Identifying Steganography Methods, Benjamin M. Rodriguez, Gilbert L. Peterson Mar 2008

Multi-Class Classification Fusion Using Boosting For Identifying Steganography Methods, Benjamin M. Rodriguez, Gilbert L. Peterson

Faculty Publications

No abstract provided.

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Sub-Symbolic Re-Representation To Facilitate Learning Transfer, Dan A. Ventura Mar 2008

Sub-Symbolic Re-Representation To Facilitate Learning Transfer, Dan A. Ventura

Faculty Publications

We consider the issue of knowledge (re-)representation in the context of learning transfer and present a subsymbolic approach for effecting such transfer. Given a set of data, manifold learning is used to automatically organize the data into one or more representational transformations, which are then learned with a set of neural networks. The result is a set of neural filters that can be applied to new data as re-representation operators. Encouraging preliminary empirical results elucidate the approach and demonstrate its feasibility, suggesting possible implications for the broader field of creativity.

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Ant Clustering With Locally Weighting Ant Perception And Diversified Memory, Gilbert L. Peterson, Christopher B. Mayer, Thomas L. Kubler Mar 2008

Ant Clustering With Locally Weighting Ant Perception And Diversified Memory, Gilbert L. Peterson, Christopher B. Mayer, Thomas L. Kubler

Faculty Publications

Ant clustering algorithms are a robust and flexible tool for clustering data that have produced some promising results. This paper introduces two improvements that can be incorporated into any ant clustering algorithm: kernel function similarity weights and a similarity memory model replacement scheme. A kernel function weights objects within an ant’s neighborhood according to the object distance and provides an alternate interpretation of the similarity of objects in an ant’s neighborhood. Ants can hill-climb the kernel gradients as they look for a suitable place to drop a carried object. The similarity memory model equips ants with a small memory consisting …

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The Importance Of Generalizability To Anomaly Detection, Gilbert L. Peterson, Brent T. Mcbride Mar 2008

The Importance Of Generalizability To Anomaly Detection, Gilbert L. Peterson, Brent T. Mcbride

Faculty Publications

In security-related areas there is concern over novel “zero-day” attacks that penetrate system defenses and wreak havoc. The best methods for countering these threats are recognizing “nonself” as in an Artificial Immune System or recognizing “self” through clustering. For either case, the concern remains that something that appears similar to self could be missed. Given this situation, one could incorrectly assume that a preference for a tighter fit to self over generalizability is important for false positive reduction in this type of learning problem. This article confirms that in anomaly detection as in other forms of classification a tight fit, …

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Conformation Of A Coarse-Grained Protein Chain (An Aspartic Acid Protease) Model In Effective Solvent By A Bond-Fluctuating Monte Carlo Simulation, Ras B. Pandey, B.L. Farmer Mar 2008

Conformation Of A Coarse-Grained Protein Chain (An Aspartic Acid Protease) Model In Effective Solvent By A Bond-Fluctuating Monte Carlo Simulation, Ras B. Pandey, B.L. Farmer

Faculty Publications

In a coarse-grained description of a protein chain, all of the 20 amino acid residues can be broadly divided into three groups: Hydrophobic (H), polar (P), and electrostatic (E). A protein can be described by nodes tethered in a chain with a node representing an amino acid group. Aspartic acid protease consists of 99 residues in a well-defined sequence of H, P, and E nodes tethered together by fluctuating bonds. The protein chain is placed on a cubic lattice where empty lattice sites constitute an effective solvent medium. The amino groups (nodes) interact with the solvent (S) sites with appropriate …

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Clouds Search For Variability In Brown Dwarf Atmospheres: Infrared Spectroscopic Time Series Of L/T Transition Brown Dwarfs, D. Stephens, B. Goldman, M. C. Cushing, M. S. Marley, E. Artigau, K. S. Baliyan, V. J. S. Bejar, J. A. Caballero, N. Chanover, M. Connelley, R. Doyon, T. Forveille, S. Ganesh, C. R. Gelino, H. B. Hammel, J. Holtzman, S. Joshi, U. C. Joshi, S. K. Leggett, M. C. Liu Feb 2008

Clouds Search For Variability In Brown Dwarf Atmospheres: Infrared Spectroscopic Time Series Of L/T Transition Brown Dwarfs, D. Stephens, B. Goldman, M. C. Cushing, M. S. Marley, E. Artigau, K. S. Baliyan, V. J. S. Bejar, J. A. Caballero, N. Chanover, M. Connelley, R. Doyon, T. Forveille, S. Ganesh, C. R. Gelino, H. B. Hammel, J. Holtzman, S. Joshi, U. C. Joshi, S. K. Leggett, M. C. Liu

Faculty Publications

L-type ultra-cool dwarfs and brown dwarfs have cloudy atmospheres that could host weather-like phenomena. The detection of photometric or spectral variability would provide insight into unresolved atmospheric heterogeneities, such as holes in a global cloud deck. Indeed, a number of ultra-cool dwarfs have been reported to vary. Additional time-resolved spectral observations of brown dwarfs offer the opportunity for further constraining and characterising atmospheric variability. Aims. It has been proposed that growth of heterogeneities in the global cloud deck may account for the L- to T-type transition when brown dwarf photospheres evolve from cloudy to clear conditions. Such a mechanism is …

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Below- And Aboveground Biomass Of Spartina Alterniflora: Response To Nutrient Addition In A Louisiana Salt Marsh, Faith A. Darby, R. Eugene Turner Feb 2008

Below- And Aboveground Biomass Of Spartina Alterniflora: Response To Nutrient Addition In A Louisiana Salt Marsh, Faith A. Darby, R. Eugene Turner

Faculty Publications

The responses of Spartina alterniflora above- and belowground biomass to various combinations of N, P, and Fe were documented in a 1-year field experiment in a Louisiana salt marsh. Five levels of N additions to 0.25 m2 plots resulted in 18% to 138% more live aboveground biomass compared to the control plots and higher stem densities, but had no effect on the amount of live belowground biomass (roots and rhizomes; R&R). There was no change in the aboveground biomass when P or Fe was added as part of a factorial experiment of +P, +N, and +Fe additions, but there was …

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Current-Voltage Characteristics Of Semiconductor/Ferromagnet Junctions In The Spin-Blockade Regime, Yuriy V. Pershin Dr, Massimiliano Di Ventra Feb 2008

Current-Voltage Characteristics Of Semiconductor/Ferromagnet Junctions In The Spin-Blockade Regime, Yuriy V. Pershin Dr, Massimiliano Di Ventra

Faculty Publications

It was recently predicted [Phys. Rev. B, 193301 (2007)] that spin blockade may develop at nonmagnetic semiconductor/perfect ferromagnet junctions when the electron flow is directed from the semiconductor into the ferromagnet. Here we consider current-voltage characteristics of such junctions. By taking into account the contact resistance, we demonstrate a current stabilization effect: by increasing the applied voltage, the current density through the junction saturates at a specific value. The transient behavior of the current density is also investigated. We show that an abrupt change in the applied voltage is accompanied by a spike in the current density. It is anticipated …

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A Precise Measurement Of The Muon Neutrino–Nucleon Inclusive Charged Current Cross Section Off An Isoscalar Target In The Energy Range 2.5 < EV < 40 Gev By Nomad, Nomad Collaboration, Q. Wu, S. R. Mishra, A. Godley, Roberto Petti, S. Alekhin, P. Astier, D. Autiero, A. Baldisseri, M. Baldo-Ceolin, M. Banner, G. Bassompierre, K. Benslama, N. Besson, I. Bird, B. Blumenfeld, F. Bobisut, J. Bouchez, S. Boyd, A. Bueno, Et. Al. Feb 2008

A Precise Measurement Of The Muon Neutrino–Nucleon Inclusive Charged Current Cross Section Off An Isoscalar Target In The Energy Range 2.5 < EV < 40 Gev By Nomad, Nomad Collaboration, Q. Wu, S. R. Mishra, A. Godley, Roberto Petti, S. Alekhin, P. Astier, D. Autiero, A. Baldisseri, M. Baldo-Ceolin, M. Banner, G. Bassompierre, K. Benslama, N. Besson, I. Bird, B. Blumenfeld, F. Bobisut, J. Bouchez, S. Boyd, A. Bueno, Et. Al.

Faculty Publications

We present a measurement of the muon neutrino–nucleon inclusive charged current cross section, off an isoscalar target, in the neutrino energy range 2.5⩽Ev ⩽ 40GeV. The significance of this measurement is its precision, ±4% in 2.5⩽Ev ⩽ 10GeV, and ± 2.6% in 10⩽Ev ⩽ 40GeV regions, where significant uncertainties in previous experiments still exist, and its importance to the current and proposed long baseline neutrino oscillation experiments.

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Quenching Of Highly Vibrationally Excited Pyrimidine By Collisions With Co4, Jeremy A. Johnson, Andrew M. Duffin, Brian J. Hom, Karl E. Jackson, Eric T. Sevy Feb 2008

Quenching Of Highly Vibrationally Excited Pyrimidine By Collisions With Co4, Jeremy A. Johnson, Andrew M. Duffin, Brian J. Hom, Karl E. Jackson, Eric T. Sevy

Faculty Publications

Relaxation of highly vibrationally excited pyrimidine (C4N2H4) by collisions with carbon dioxide has been investigated using diode laser transient absorption spectroscopy. Vibrationally hot pyrimidine (E'=40,635 cm^-1) was prepared by 248-nm excimer laser excitation, followed by rapid radiationless relaxation to the ground electronic state. The nascent rotational population distribution (J=58–80) of the 0000 ground state of CO2 resulting from collisions with hot pyrimidine was probed at short times following the excimer laser pulse. Doppler spectroscopy was used to measure the CO2 recoil velocity distribution for J=58–80 of the 0000 state. Rate constants and probabilities for collisions populating these CO2 rotational states …

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Ozone Exposure In A Mouse Model Induces Airway Hyperreactivity That Requires The Presence Of Natural Killer T Cells And Il-17, Paul B. Savage, Muriel Pichavant, Sho Goya, Everett H. Meyer, Richard A. Johnston, Hye Y. Kim, Ponpan Matangkasombut, Ming Zhu, Yoichiro Iwakura, Rosemarie H. Dekruyff, Stephanie A. Shore, Dale T. Umetsu Feb 2008

Ozone Exposure In A Mouse Model Induces Airway Hyperreactivity That Requires The Presence Of Natural Killer T Cells And Il-17, Paul B. Savage, Muriel Pichavant, Sho Goya, Everett H. Meyer, Richard A. Johnston, Hye Y. Kim, Ponpan Matangkasombut, Ming Zhu, Yoichiro Iwakura, Rosemarie H. Dekruyff, Stephanie A. Shore, Dale T. Umetsu

Faculty Publications

Exposure to ozone, which is a major component of air pollution, induces a form of asthma that occurs in the absence of adaptive immunity. Although ozone-induced asthma is characterized by airway neutrophilia, and not eosinophilia, it is nevertheless associated with airway hyperreactivity (AHR), which is a cardinal feature of asthma. Because AHR induced by allergens requires the presence of natural killer T (NKT) cells, we asked whether ozone-induced AHR had similar requirements. We found that repeated exposure of wild-type (WT) mice to ozone induced severe AHR associated with an increase in airway NKT cells, neutrophils, and macrophages. Surprisingly, NKT cell-deficient …

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Using Plsi-U To Detect Insider Threats By Datamining Email, James S. Okolica, Gilbert L. Peterson, Robert F. Mills Feb 2008

Using Plsi-U To Detect Insider Threats By Datamining Email, James S. Okolica, Gilbert L. Peterson, Robert F. Mills

Faculty Publications

Despite a technology bias that focuses on external electronic threats, insiders pose the greatest threat to an organisation. This paper discusses an approach to assist investigators in identifying potential insider threats. We discern employees' interests from e-mail using an extended version of PLSI. These interests are transformed into implicit and explicit social network graphs, which are used to locate potential insiders by identifying individuals who feel alienated from the organisation or have a hidden interest in a sensitive topic. By applying this technique to the Enron e-mail corpus, a small number of employees appear as potential insider threats.

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Doping Of A One-Dimensional Mott Insulator: Photoemission And Optical Studies Of Sr2cu03+Δ, Tim Kidd, T. Valla, P. D. Johnson, K. W. Kim, G. D. Gu, C. C. Homes Feb 2008

Doping Of A One-Dimensional Mott Insulator: Photoemission And Optical Studies Of Sr2cu03+Δ, Tim Kidd, T. Valla, P. D. Johnson, K. W. Kim, G. D. Gu, C. C. Homes

Faculty Publications

Angle-resolved photoemission and optical spectroscopy are used to probe the electronic structure of the one-dimensional Mott insulator Sr2CuO3+δ, both at half-filling and with small concentrations of excess oxygen doping. Spin-charge separation can be seen as evidenced by the existence of spinon and holon branches in the photoemission spectra. Optical studies reveal no significant doping dependence, while photoemission studies show a large energy shift in the spinon and holon states with respect to the main valence band states which remain nearly unaffected. The results suggest the excess dopant carriers are incorporated solely within the one-dimensional Hubbard band …

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Oligocene Deep Water Export From The North Atlantic And The Development Of The Antarctic Circumpolar Current Examined With Neodymium Isotopes, Howie Scher, Ellen E. Martin Jan 2008

Oligocene Deep Water Export From The North Atlantic And The Development Of The Antarctic Circumpolar Current Examined With Neodymium Isotopes, Howie Scher, Ellen E. Martin

Faculty Publications

Neodymium (Nd) isotopes were measured on 181 samples of fossil fish teeth recovered from Oligocene toMiocene sections at Ocean Drilling Program Site 1090 (3700 m water depth) on Agulhas Ridge in the Atlanticsector of the Southern Ocean. A long-term decreasing trend toward less radiogenic Nd isotope compositionsdominates the record. This trend is interrupted by shifts toward more radiogenic compositions near the early/lateOligocene boundary and the Oligocene/Miocene boundary. Overall, eNd values at Agulhas Ridge are moreradiogenic than at other Atlantic locations, and are similar to those at Indian Ocean locations. The pattern ofvariability is remarkably similar to Nd isotope results from …

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All-Sky Search For Periodic Gravitational Waves In Ligo S4 Data, B. Abbott, R. Abbott, R. Adhikari, J. Agresti, P. Ajith, B. Allen, R. Amin, S. B. Anderson, W. G. Anderson, M. Arain, M. Araya, H. Armandula, M. Ashley, S. Aston, P. Aufmuth, C. Aulbert, S. Babak, S. Ballmer, H. Bantilan, B. C. Barish, C. Barker, D. Barker, B. Barr, P. Barriga, M. A. Barton, K. Bayer, K. Belczynski, J. Betzwieser, P. T. Beyersdorf, B. Bhawal, I. A. Bilenko, Tiffany Z. Summerscales Jan 2008

All-Sky Search For Periodic Gravitational Waves In Ligo S4 Data, B. Abbott, R. Abbott, R. Adhikari, J. Agresti, P. Ajith, B. Allen, R. Amin, S. B. Anderson, W. G. Anderson, M. Arain, M. Araya, H. Armandula, M. Ashley, S. Aston, P. Aufmuth, C. Aulbert, S. Babak, S. Ballmer, H. Bantilan, B. C. Barish, C. Barker, D. Barker, B. Barr, P. Barriga, M. A. Barton, K. Bayer, K. Belczynski, J. Betzwieser, P. T. Beyersdorf, B. Bhawal, I. A. Bilenko, Tiffany Z. Summerscales

Faculty Publications

We report on an all-sky search with the LIGO detectors for periodic gravitational waves in the frequency range 50-1000 Hz and with the frequency's time derivative in the range -1×10-8Hzs-1 to zero. Data from the fourth LIGO science run (S4) have been used in this search. Three different semicoherent methods of transforming and summing strain power from short Fourier transforms (SFTs) of the calibrated data have been used. The first, known as StackSlide, averages normalized power from each SFT. A "weighted Hough" scheme is also developed and used, which also allows for a multi-interferometer search. The third method, known as …

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Illustrating The Use Of The Nine Chapters In The Classroom, Joel K. Haack Jan 2008

Illustrating The Use Of The Nine Chapters In The Classroom, Joel K. Haack

Faculty Publications

No abstract provided.

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Castile Evaporite Karst Potential Map Of The Gypsum Plain, Eddy County, New Mexico And Culberson County, Texas: A Gis Methodological Comparison, Kevin W. Stafford, Laura Rosales-Lagarde, Penelope J. Boston Jan 2008

Castile Evaporite Karst Potential Map Of The Gypsum Plain, Eddy County, New Mexico And Culberson County, Texas: A Gis Methodological Comparison, Kevin W. Stafford, Laura Rosales-Lagarde, Penelope J. Boston

Faculty Publications

Castile Formation gypsum crops out over ,1,800 km2 in the western Delaware Basin where it forms the majority of the Gypsum Plain. Karst development is well recognized in the Gypsum Plain (i.e., filled and open sinkholes with associated caves); however, the spatial occurrence has been poorly known. In order to evaluate the extent and distribution of karst development within the Castile portion of the Gypsum Plain, combined field and Geographic Information System (GIS) studies were conducted, which enable a first approximation of regional speleogenesis and delineate karst-related natural resources for management. Field studies included physical mapping of 50, 1-km2 sites, …

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Hypogene Speleogenesis Within The Central Basin Platform: Karst Porosity In The Yates Field, Pecos County, Texas, U.S.A., Kevin W. Stafford, Fred H. Behnken, Jesse G. White Jan 2008

Hypogene Speleogenesis Within The Central Basin Platform: Karst Porosity In The Yates Field, Pecos County, Texas, U.S.A., Kevin W. Stafford, Fred H. Behnken, Jesse G. White

Faculty Publications

The Yates Unit Oil Field is located on the southeastern tip of the Central Basin Platform in eastern Pecos County, Texas. It produces from Middle Permian strata, primarily the upper San Andres Formation. Locally, the productive upper San Andres Formation is comprised of successively vertically stacked progradational shelf carbonates. Stratigraphically overlying the Yates Field reservoir, the Toborg Field produces from the uppermost Triassic and Cretaceous units. Both fields are bounded on the north and east sides by the Pecos River, which has remained entrenched in its current location since the early Tertiary. As mapped, the top of the San Andres …

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Hypogene Calcitization: Evaporite Diagenesis In The Western Delaware Basin, Kevin W. Stafford, Dana Ulmer-Scholle, Laura Rosales-Lagarde Jan 2008

Hypogene Calcitization: Evaporite Diagenesis In The Western Delaware Basin, Kevin W. Stafford, Dana Ulmer-Scholle, Laura Rosales-Lagarde

Faculty Publications

Evaporite calcitization within the Castile Formation of the Delaware Basin is more widespread and diverse than originally recognized. Coupled field and GIS studies have identified more than 1000 individual occurrences of calcitization within the Castile Formation outcrop area, which includes both calcitized masses (limestone buttes) and laterally extensive calcitized horizons (limestone sheets). Both limestone buttes and sheets commonly contain a central brecciated zone that we attribute to hypogene dissolution. Lithologic fabric of calcitized zones ranges from little alteration of original varved laminae to fabrics showing extensive laminae distortion as well as extensive vuggy and open cavernous porosity. Calcitization is most …

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Use Of Trees By The Texas Ratsnake (Elaphe Obsoleta) In Eastern Texas, Josh B. Pierce, Robert R. Fleet, Lance Mcbrayer, D. Craig Rudolph Jan 2008

Use Of Trees By The Texas Ratsnake (Elaphe Obsoleta) In Eastern Texas, Josh B. Pierce, Robert R. Fleet, Lance Mcbrayer, D. Craig Rudolph

Faculty Publications

We present information on the use of trees by Elaphe obsoleta (Texas Ratsnake) in a mesic pine-hardwood forest in eastern Texas. Using radiotelemetry, seven snakes (3 females, 4 males) were relocated a total of 363 times from April 2004 to May 2005, resulting in 201 unique locations. Snakes selected trees containing cavities and used hardwoods and snags for a combined 95% of arboreal locations. Texas Ratsnake arboreal activity peaked during July and August, well after the peak of avian breeding activity, suggesting arboreal activity involves factors other than avian predation.

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Delta Function For An Affine Subspace, Jeremy Becnel Jan 2008

Delta Function For An Affine Subspace, Jeremy Becnel

Faculty Publications

The Kubo–Yokoi and Donsker delta functions are well known generalized functions in infinite dimensional distribution theory. In this paper we develop the delta function for an affine subspace and show that it is a generalization of the Kubo–Yokoi and Donsker delta functions. The Wiener– Itˆo expansion of the delta function for an affine subspace is also given.

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A Geowall With Physics And Astronomy Applications, Phillip Dukes, Dan Bruton Jan 2008

A Geowall With Physics And Astronomy Applications, Phillip Dukes, Dan Bruton

Faculty Publications

A GeoWall is a passive stereoscopic projection system that can be used by students, teachers, and researchers for visualization of the structure and dynamics of three-dimensional systems and data. The type of system described here adequately provides 3-D visualization in natural color for large or small groups of viewers. The name “GeoWall” derives from its initial development to visualize data in the geosciences.1 An early GeoWall system was developed by Paul Morin at the electronic visualization laboratory at the University of Minnesota and was applied in an introductory geology course in spring of 2001. Since that time, several stereoscopic media, …

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Singlet Oxygen Chemistry In Water:  A Porous Vycor Glasssupported Photosensitizer, David Aebisher, Nikolay S. Azar, Matibur Zamadar, Naveen Gandra, Harry D. Gafney, Roumei Gao, Alexander Greer Jan 2008

Singlet Oxygen Chemistry In Water:  A Porous Vycor Glasssupported Photosensitizer, David Aebisher, Nikolay S. Azar, Matibur Zamadar, Naveen Gandra, Harry D. Gafney, Roumei Gao, Alexander Greer

Faculty Publications

Singlet molecular oxygen [1O2 (1Δg)] is generated cleanly in aqueous solution upon irradiation of a heterogeneous complex, meso-tetra(N-methyl-4-pyridyl)porphine (1) adsorbed onto porous Vycor glass (PVG). The cationic photosensitizer 1 tightly binds onto PVG and gives a stable material, which does not dissociate 1 into the surrounding aqueous phase. The production of 1O2 was measured by monitoring the time-resolved 1O2 (1Δg) phosphorescence at 1270 nm. Indirect analysis of 1O2 generation was also carried out with the photooxidation oftrans-2-methyl-2-pentenoate anion, which afforded the corresponding hydroperoxide. Sensitizer-1-impregnated PVG gives rise to a new singlet …

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Singlet Oxygen Chemistry In Water. 2. Photoexcited Sensitizer Quenching By O2 At The Water−Porous Glass Interface, Jovan Giaimuccio, Matibur Zamadar, David Aebisher, Gerald J. Meyer, Alexander Greer Jan 2008

Singlet Oxygen Chemistry In Water. 2. Photoexcited Sensitizer Quenching By O2 At The Water−Porous Glass Interface, Jovan Giaimuccio, Matibur Zamadar, David Aebisher, Gerald J. Meyer, Alexander Greer

Faculty Publications

Insight into the O2 quenching mechanism of a photosensitizer (static or dynamic) would be useful for the design of heterogeneous systems to control the mode of generation of 1O2 in water. Here, we describe the use of a photosensitizer, meso-tetra(N-methyl-4-pyridyl)porphine (1), which was adsorbed onto porous Vycor glass (PVG). A maximum loading of 1.1 × 10−6 mol 1 per g PVG was achieved. Less than 1% of the PVG surface was covered with photosensitizer 1, and the penetration of 1 reaches a depth of 0.32 mm along all faces of the glass. Time-resolved measurements …

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Evidence Contrary To The Statistical View Of Boosting, David Mease, A. Wyner Jan 2008

Evidence Contrary To The Statistical View Of Boosting, David Mease, A. Wyner

Faculty Publications

The statistical perspective on boosting algorithms focuses on optimization, drawing parallels with maximum likelihood estimation for logistic regression. In this paper we present empirical evidence that raises questions about this view. Although the statistical perspective provides a theoretical framework within which it is possible to derive theorems and create new algorithms in general contexts, we show that there remain many unanswered important questions. Furthermore, we provide examples that reveal crucial flaws in the many practical suggestions and new methods that are derived from the statistical view. We perform carefully designed experiments using simple simulation models to illustrate some of these …

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Stochastic Hard-Sphere Dynamics For Hydrodynamics Of Non-Ideal Fluids, Alejandro Garcia, A. Donev, B. J. Alder Jan 2008

Stochastic Hard-Sphere Dynamics For Hydrodynamics Of Non-Ideal Fluids, Alejandro Garcia, A. Donev, B. J. Alder

Faculty Publications

A novel stochastic fluid model is proposed with a nonideal structure factor consistent with compressibility, and adjustable transport coefficients. This stochastic hard sphere dynamics (SHSD) algorithm is a modification of the direct simulation Monte Carlo algorithm and has several computational advantages over event-driven hard-sphere molecular dynamics. Surprisingly, SHSD results in an equation of state and a pair correlation function identical to that of a deterministic Hamiltonian system of penetrable spheres interacting with linear core pair potentials. The fluctuating hydrodynamic behavior of the SHSD fluid is verified for the Brownian motion of a nanoparticle suspended in a compressible solvent.

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