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2010

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Articles 5611 - 5640 of 8625

Full-Text Articles in Physical Sciences and Mathematics

Spatially Resolved Polycyclic Aromatic Hydrocarbon Emission Features In Nearby, Low Metallicity, Star-Forming Galaxies, Korey Haynes, John M. Cannon, Evan D. Skillman, Dale C. Jackson, Robert D. Gehrz Jan 2010

Spatially Resolved Polycyclic Aromatic Hydrocarbon Emission Features In Nearby, Low Metallicity, Star-Forming Galaxies, Korey Haynes, John M. Cannon, Evan D. Skillman, Dale C. Jackson, Robert D. Gehrz

John Cannon

No abstract provided.

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Impact Of Hurricane Katrina (2005) On Shelf Organic Carbon Burial And Deltaic Evolution, Steven T. Petsch, Mead A. Allison, Timothy M. Dellapenna, Elizabeth S. Gordon, Siddhartha Mitra Jan 2010

Impact Of Hurricane Katrina (2005) On Shelf Organic Carbon Burial And Deltaic Evolution, Steven T. Petsch, Mead A. Allison, Timothy M. Dellapenna, Elizabeth S. Gordon, Siddhartha Mitra

Steven T. Petsch

Sediment cores from the continental shelf adjacent to the Mississippi River delta immediately after the passage of Hurricane Katrina were used to examine the magnitude, and implications for the carbon budget, of sediment and particulate organic carbon (POC) remobilized by the storm on the river-dominated continental shelf. POC was sourced from incision of the innermost continental shelf (<25 m water depth) and from surge ebb advection from adjacent wetlands and shallow estuaries, and was re-deposited in deeper water on the shelf. This pulse of young (<1,600 yBP) labile POC, mixed with relict (>5000 yBP) POC eroded from the seafloor, has major implications for the remineralization versus burial of POC in deltas. The scale of erosional deflation of the shelf in water depths beyond seasonal wave-current conditions suggests that, over millennia, tropical cyclones may be …

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Subhorizontal Fabric In Exhumed Continental Lower Crust And Implications For Lower Crustal Flow: Athabasca Granulite Terrane, Western Canadian Shield, Gregory Dumond, Philippe Goncalves, Michael L. Williams, Michael J. Jercinovic Jan 2010

Subhorizontal Fabric In Exhumed Continental Lower Crust And Implications For Lower Crustal Flow: Athabasca Granulite Terrane, Western Canadian Shield, Gregory Dumond, Philippe Goncalves, Michael L. Williams, Michael J. Jercinovic

Michael J Jercinovic

The >20,000 km2 Athabasca granulite terrane is one of Earth's largest exposures of continental lower crust. The terrane is underlain by heterogeneous isobarically cooled orthogneisses termed the Mary batholith. A transect across the batholith documents early, penetrative subhorizontal to gently dipping gneissic foliation (S1). Kilometer- to meter-scale domains of S1 contain lineations (L1) defined by ribbons of recrystallized K-feldspar + plagioclase + quartz + amphibole ± orthopyroxene. L1 coincides with garnet aggregates, elongate mafic enclaves, and core-and-mantle structure in feldspar porphyroclasts. Lineations are coaxial with hinges of isoclinally folded layering (F1). L1 is interpreted as a composite mineral lineation with …

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Gis @ Ut Libraries, Allison Roberts Jan 2010

Gis @ Ut Libraries, Allison Roberts

Allison Roberts

Information handout/poster for GIS services at UT

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Determining Rates Of Virus Production In Aquatic Systems By The Virus Reduction Approach,, M.G. Weinbauer, J.M. Rowe, Steven Wilhelm Jan 2010

Determining Rates Of Virus Production In Aquatic Systems By The Virus Reduction Approach,, M.G. Weinbauer, J.M. Rowe, Steven Wilhelm

Steven Wilhelm

The reduction approach to assess virus production and the prokaryotic mortality by viral lysis stops new infection by reducing total virus abundance (and thus virus–host contacts). This allows for easy enumeration of viruses that originate from lysis of already infected cells due to the decreased abundance of free virus particles. This reoccurrence can be quantified and used to assess production and cell lysis rates. Several modifications of the method are presented and compared. The approaches have great potential for elucidating trends in virus production rates as well as for making generalized estimates of the quantitative effects of viruses on marine …

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The Construction And Analysis Of Marker Gene Libraries, S.M. Short, F. Chen, Steven Wilhelm Jan 2010

The Construction And Analysis Of Marker Gene Libraries, S.M. Short, F. Chen, Steven Wilhelm

Steven Wilhelm

Marker genes for viruses are typically amplified from aquatic samples to determine whether specific viruses are present in the sample, or to examine the diversity of a group of related viruses. In this chapter, we will provide an overview of common methods used to amplify, clone, sequence, and analyze virus marker genes, and will focus our discussion on viruses infecting algae, bacteria, and heterotrophic flagellates. Within this chapter, we endeavor to highlight critical aspects and components of these methods. To this end, instead of providing a detailed experimental protocol for each of the steps involved in examining virus marker gene …

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Commissioning And Performance Of The Cms Pixel Tracker With Cosmic Ray, Serguei Chatrchyan Muons, Stefan Spanier Jan 2010

Commissioning And Performance Of The Cms Pixel Tracker With Cosmic Ray, Serguei Chatrchyan Muons, Stefan Spanier

stefan spanier

The pixel detector of the Compact Muon Solenoid experiment consists of three barrel layers and two disks for each endcap. The detector was installed in summer 2008, commissioned with charge injections, and operated in the 3.8 T magnetic field during cosmic ray data taking. This paper reports on the first running experience and presents results on the pixel tracker performance, which are found to be in line with the design specifications of this detector. The transverse impact parameter resolution measured in a sample of high momentum muons is 18 microns.

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Observation Of Long-Range Near-Side Angular Correlations In Proton-Proton Collisions At The Lhc, Stefan Spanier Jan 2010

Observation Of Long-Range Near-Side Angular Correlations In Proton-Proton Collisions At The Lhc, Stefan Spanier

stefan spanier

Results on two-particle angular correlations for charged particles emitted in proton-proton collisions at center-of-mass energies of 0.9, 2.36, and 7 TeV are presented, using data collected with the CMS detector over a broad range of pseudorapidity (eta) and azimuthal angle (phi). Short-range correlations in Delta(eta), which are studied in minimum bias events, are characterized using a simple "independent cluster" parametrization in order to quantify their strength (cluster size) and their extent in eta (cluster decay width). Long-range azimuthal correlations are studied differentially as a function of charged particle multiplicity and particle transverse momentum using a 980 inverse nb data set …

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Results From A Beam Test Of A Prototype Plt Diamond Pixel Telescope, R. Hall-Wilton, R. Loos, V. Ryjov, M. Pernicka, S. Schmied, H. Steninger, V. Halyo, B. Harrop, A. Hunt, D. Marlow, B. Sands, D. Strickland, O. Atramentov, E. Bartz, J. Doroshenko, Y. Gershtein, D. Hits, S. Schnetzer, R. Stone, P. Bulter, S. Lansley, N. Rodrigues, W. Bugg, M Hollingsworth, Stefan Spanier, W. Johns Jan 2010

Results From A Beam Test Of A Prototype Plt Diamond Pixel Telescope, R. Hall-Wilton, R. Loos, V. Ryjov, M. Pernicka, S. Schmied, H. Steninger, V. Halyo, B. Harrop, A. Hunt, D. Marlow, B. Sands, D. Strickland, O. Atramentov, E. Bartz, J. Doroshenko, Y. Gershtein, D. Hits, S. Schnetzer, R. Stone, P. Bulter, S. Lansley, N. Rodrigues, W. Bugg, M Hollingsworth, Stefan Spanier, W. Johns

stefan spanier

We describe results from a beam test of a telescope consisting of three planes of single-crystal, diamond pixel detectors. This telescope is a prototype for a small-angle luminosity monitor, the Pixel Luminosity Telescope (PLT), for CMS. We recorded the pixel addresses and pulse heights of all pixels over threshold as well as the fast-or signals from all three telescope planes. We present results on the telescope performance including occupancies, pulse heights, fast-or efficiencies and particle tracking. These results show that the PLT design meets all required specifications.

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An Integrated Collection Of Tools For Continuously Improving The Processes By Which Health Care Is Delivered: A Tool Report, Lj Osterweil, La Clarke, Gs Avrunin Jan 2010

An Integrated Collection Of Tools For Continuously Improving The Processes By Which Health Care Is Delivered: A Tool Report, Lj Osterweil, La Clarke, Gs Avrunin

Leon Osterweil

With the availability of powerful computational and commu- nication systems, scientists now readily access large, complicated derived datasets and build on those results to produce, through further processing, yet other derived datasets of interest. The scientific processes used to create such datasets must be clearly documented so that scientists can evaluate their soundness, reproduce the results, and build upon them in responsible and appropriate ways. Here, we present the concept of an analytic web, which defines the scientific processes employed and details the exact appli- cation of those processes in creating derived datasets. The work described here is similar to …

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High-Performance Semi-Supervised Learning Using Discriminatively Constrained Generative Models, Gregory Druck, Andrew Mccallum Jan 2010

High-Performance Semi-Supervised Learning Using Discriminatively Constrained Generative Models, Gregory Druck, Andrew Mccallum

Andrew McCallum

We develop a semi-supervised learning algorithm that encourages generative models to discover latent structure that is relevant to a prediction task. The method constrains the posterior distribution of latent variables under a generative model to satisfy a rich set of feature expectation constraints from labeled data. We focus on the application of this method to sequence labeling and estimate parameters with a modified EM algorithm. The E-step involves estimating the parameters of a log-linear model with an HMM as the base distribution. This HMM-CRF can be used for test time prediction. The approach is related to other semi-supervised methods, but …

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Collective Cross-Document Relation Extraction Without Labelled Data, Limin Yao, Sebastian Riedel, Andrew Mccallum Jan 2010

Collective Cross-Document Relation Extraction Without Labelled Data, Limin Yao, Sebastian Riedel, Andrew Mccallum

Andrew McCallum

We present a novel approach to relation extraction that integrates information across documents, performs global inference and requires no labelled text. In particular, we tackle relation extraction and entity identification jointly. We use distant supervision to train a factor graph model for relation extraction based on an existing knowledge base (Freebase, derived in parts from Wikipedia). For inference we run an efficient Gibbs sampler that leads to linear time joint inference. We evaluate our approach both for an in-domain (Wikipedia) and a more realistic out-of-domain (New York Times Corpus) setting. For the in-domain setting, our joint model leads to 4% …

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Modeling Relations And Their Mentions Without Labeled Text, Sebastian Riedel, Limin Yao, Andrew Mccallum Jan 2010

Modeling Relations And Their Mentions Without Labeled Text, Sebastian Riedel, Limin Yao, Andrew Mccallum

Andrew McCallum

Several recent works on relation extraction have been applying the distant supervision paradigm: instead of relying on annotated text to learn how to predict relations, they employ existing knowledge bases (KBs) as source of supervision. Crucially, these approaches are trained based on the assumption that each sentence which mentions the two related entities is an expression of the given relation. Here we argue that this leads to noisy patterns that hurt precision, in particular if the knowledge base is not directly related to the text we are working with. We present a novel approach to distant supervision that can alleviate …

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Revelations Of Adaptive Technology Hiding In Your Operating System, Kathleen P. King Jan 2010

Revelations Of Adaptive Technology Hiding In Your Operating System, Kathleen P. King

Kathleen P King

Pre-publication version of a chapter about the assistive technology tools and resources available for free in Windows OS and Mac OS. Introducing higher education faculty to free resources, features and programs which they can recommend to their students or perhaps use for themselves (for instance for fading eyesight or hearing). In addition, the chapter briefly shares strategies and examples of how they might be used. The book will have an entire chapter dedicated to assistive technology as well. This is a popularized assistive technology chapter for generalist, NON special education, faculty to become acquainted with readily available and free resources. …

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Existence Of Traveling Wave Solutions For A Nonlocal Reaction-Diffusion Model Of Influenza A Drift, Joaquin Riviera, Yi Li Jan 2010

Existence Of Traveling Wave Solutions For A Nonlocal Reaction-Diffusion Model Of Influenza A Drift, Joaquin Riviera, Yi Li

Yi Li

In this paper we discuss the existence of traveling wave solutions for a nonlocal reaction-diffusion model of Influenza A proposed in Lin et. al. (2003). The proof for the existence of the traveling wave takes advantage of the different time scales between the evolution of the disease and the progress of the disease in the population. Under this framework we are able to use the techniques from geometric singular perturbation theory to prove the existence of the traveling wave.

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Constraint-Driven Rank-Based Learning For Information Extraction, Sameer Singh, Limin Yao, Sebastian Riedel, Andrew Mccallum Jan 2010

Constraint-Driven Rank-Based Learning For Information Extraction, Sameer Singh, Limin Yao, Sebastian Riedel, Andrew Mccallum

Andrew McCallum

Most learning algorithms for factor graphs require complete inference over the dataset or an instance before making an update to the parameters. SampleRank is a rank-based learning framework that alleviates this problem by updating the parameters during inference. Most semi-supervised learning algorithms also rely on the complete inference, i.e. calculating expectations or MAP configurations. We extend the SampleRank framework to the semi-supervised learning, avoiding these inference bottlenecks. Different approaches for incorporating unlabeled data and prior knowledge into this framework are explored. We evaluated our method on a standard information extraction dataset. Our approach outperforms the supervised method significantly and matches …

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Resource-Bounded Information Extraction: Acquiring Missing Feature Values On Demand, Pallika Kanani, Andrew Mccallum, Shaohan Hu Jan 2010

Resource-Bounded Information Extraction: Acquiring Missing Feature Values On Demand, Pallika Kanani, Andrew Mccallum, Shaohan Hu

Andrew McCallum

We present a general framework for the task of extracting specific information ``on demand'' from a large corpus such as the Web under resource-constraints. Given a database with missing or uncertain information, the proposed system automatically formulates queries, issues them to a search interface, selects a subset of the documents, extracts the required information from them, and fills the missing values in the original database. We also exploit inherent dependency within the data to obtain useful information with fewer computational resources. We build such a system in the citation database domain that extracts the missing publication years using limited resources …

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Optimizing Semantic Coherence In Topic Models, D. Mimno, H. Wallach, E. Talley, M. Leenders, Andrew Mccallum Jan 2010

Optimizing Semantic Coherence In Topic Models, D. Mimno, H. Wallach, E. Talley, M. Leenders, Andrew Mccallum

Andrew McCallum

Large organizations often face the critical challenge of sharing information and maintaining connections between disparate subunits. Tools for automated analysis of document collections, such as topic models, can provide an important means for communication. The value of topic modeling is in its ability to discover interpretable, coherent themes from unstructured document sets, yet it is not unusual to find semantic mismatches that substantially reduce user confidence. In this paper, we first present an expert-driven topic annotation study, undertaken in order to obtain an annotated set of baseline topics and their distinguishing characteristics. We then present a metric for detecting poor-quality …

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Aqua Science Through The Ages. An Illustrated History Of Water, Fathi Habashi Jan 2010

Aqua Science Through The Ages. An Illustrated History Of Water, Fathi Habashi

Fathi Habashi

Water a component of the Four Elements considered by the ancient philosophers as essential for survival, played, and is still playing an essential role in society. Great civilizations in ancient times developed along great rivers. The ancient peoples knew how to manage water supplies by digging canals, controlling floods, and using water for irrigation. They designed equipment that used water to measure the time, to determine the density of solids, to fight fires, and to create vacuum. Modern engineers exploited water flow to design and construct huge hydroelectric power stations. Waterways and navigation systems were also an essential element for …

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Pollution And Public Health In A Shrinking World: Concentrated Animal Feeding Operations As A Paradigm For Emergent Needs In Environmental And Public Health Policy, Leland Stillman Jan 2010

Pollution And Public Health In A Shrinking World: Concentrated Animal Feeding Operations As A Paradigm For Emergent Needs In Environmental And Public Health Policy, Leland Stillman

Self-Designed Majors Honors Papers

Environmental factors play a major part in human health. Environmental pollutants are often as poisonous to humans as the environment. Presently, much time and energy is dedicated to keeping pollution apart from human society, with varying success. But as global population densities rise, current levels of pollution will become inviable due to public health concerns. An emergent example of this is in the concentration of livestock operations. Recent changes in the structure of U.S. hog farming have resulted in an industry-wide shift from small or medium production farms to high capacity, “concentrated animal feeding operations” (CAFO). These operations have become …

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The Linus Sequence, Paul Balister, Steven Kalikow, Amites Sarkar Jan 2010

The Linus Sequence, Paul Balister, Steven Kalikow, Amites Sarkar

Mathematics Faculty Publications

Define the Linus sequence Ln for n ≥ 1 as a 0–1 sequence with L1 = 0, and Ln chosen so as to minimize the length of the longest immediately repeated block Ln−2r+1 Ln−r = Ln−r+1 Ln. Define the Sally sequence Sn as the length r of the longest repeated block that was avoided by the choice of Ln. We prove several results about these sequences, such as exponential decay of the frequency of highly periodic subwords of the Linus sequence, zero entropy of any …

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Gauge Equivalence In Stationary Radiative Transport Through Media With Varying Index Of Refraction, Stephen R. Mcdowall, Plamen Stefanov, Alexandru Tamasan Jan 2010

Gauge Equivalence In Stationary Radiative Transport Through Media With Varying Index Of Refraction, Stephen R. Mcdowall, Plamen Stefanov, Alexandru Tamasan

Mathematics Faculty Publications

Three dimensional anisotropic attenuating and scattering media sharing the same albedo operator have been shown to be related via a gauge transformation. Such transformations define an equivalence relation. We show that the gauge equivalence is also valid in media with non-constant index of refraction, modeled by a Riemannian metric. The two dimensional model is also investigated.

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Anisotropic Classes Of Homogeneous Pseudodifferential Symbols, Árpád Bényi, Marcin Bownik Jan 2010

Anisotropic Classes Of Homogeneous Pseudodifferential Symbols, Árpád Bényi, Marcin Bownik

Mathematics Faculty Publications

We define homogeneous classes of x-dependent anisotropic symbols S˙mγ,δ(A) in the framework determined by an expansive dilation A, thus extending the existing theory for diagonal dilations. We revisit anisotropic analogues of Hörmander–Mikhlin multipliers introduced by Rivière [Ark. Mat. 9 (1971)] and provide direct proofs of their boundedness on Lebesgue and Hardy spaces by making use of the well-established Calderón–Zygmund theory on spaces of homogeneous type. We then show that x-dependent symbols in S˙01,1(A) yield Calderón–Zygmund kernels, yet their L2 boundedness fails. Finally, we prove boundedness results …

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On The Hörmander Classes Of Bilinear Pseudodifferential Operators, Árpád Bényi, Diego Maldonado, Virginia Naibo, Rodolfo H. (Rodolfo Humberto) Torres Jan 2010

On The Hörmander Classes Of Bilinear Pseudodifferential Operators, Árpád Bényi, Diego Maldonado, Virginia Naibo, Rodolfo H. (Rodolfo Humberto) Torres

Mathematics Faculty Publications

Bilinear pseudodifferential operators with symbols in the bilinear analog of all the Hörmander classes are considered and the possibility of a symbolic calculus for the transposes of the operators in such classes is investigated. Precise results about which classes are closed under transposition and can be characterized in terms of asymptotic expansions are presented. This work extends the results for more limited classes studied before in the literature and, hence, allows the use of the symbolic calculus (when it exists) as an alternative way to recover the boundedness on products of Lebesgue spaces for the classes that yield operators with …

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Sentry Selection In Wireless Networks, Paul Balister, Béla Bollobás, Amites Sarkar, Mark Walters Jan 2010

Sentry Selection In Wireless Networks, Paul Balister, Béla Bollobás, Amites Sarkar, Mark Walters

Mathematics Faculty Publications

Let P be a Poisson process of intensity one in the infinite plane R2. We surround each point x of P by the open disc of radius r centred at x. Now let Sn be a fixed disc of area n, and let Cr(Sn) be the set of discs which intersect Sn. Write Erk for the event that Cr(Sn) is a k-cover of Sn, and Frk for the event that Cr(Sn) …

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Secrecy Coverage (Conference Proceeding), Amites Sarkar, Martin Haenggi Jan 2010

Secrecy Coverage (Conference Proceeding), Amites Sarkar, Martin Haenggi

Mathematics Faculty Publications

Motivated by information-theoretic secrecy, geometric models for secrecy in wireless networks have begun to receive increased attention. The general question is how the presence of eavesdroppers affects the properties and performance of the network. Previously the focus has been mostly on connectivity. Here we study the impact of eavesdroppers on the coverage of a network of base stations. The problem we address is the following. Let base stations and eavesdroppers be distributed as stationary Poisson point processes in a disk of area n. If the coverage of each base station is limited by the distance to the nearest eavesdropper, …

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Bifurcation Of Solutions Of Separable Parameterized Equations Into Lines, Tjalling Ypma, Yun-Qiu Shen Jan 2010

Bifurcation Of Solutions Of Separable Parameterized Equations Into Lines, Tjalling Ypma, Yun-Qiu Shen

Mathematics Faculty Publications

Many applications give rise to separable parameterized equations of the form A(y,µ)z + b(y, µ) = 0, where y ∈ Rn, z ∈ RN and the parameter µ ∈ R; here A(y,µ) is an (N + n) × N matrix and b(y, µ) ∈ RN +n. Under the assumption that A(y, µ) has full rank we showed in [21] that bifurcation points can be located by solving a reduced equation of the form f ( …

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Zeros Of Some Level 2 Eisenstein Series, Sharon Garthwaite, Ling Long, Holly Swisher, Stephanie Treneer Jan 2010

Zeros Of Some Level 2 Eisenstein Series, Sharon Garthwaite, Ling Long, Holly Swisher, Stephanie Treneer

Mathematics Faculty Publications

The zeros of classical Eisenstein series satisfy many intriguing properties. Work of F. Rankin and Swinnerton-Dyer pinpoints their location to a certain arc of the fundamental domain, and recent work by Nozaki explores their interlacing property. In this paper we extend these distribution properties to a particular family of Eisenstein series on Γ(2) because of its elegant connection to a classical Jacobi elliptic function cn(u) which satisfies a differential equation (see formula (1.2)). As part of this study we recursively define a sequence of polynomials from the differential equation mentioned above that allow us to calculate zeros …

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Rare's Implementation Strategies Of Environmental Conservation In Indonesia, Alvaro Arvizo Jan 2010

Rare's Implementation Strategies Of Environmental Conservation In Indonesia, Alvaro Arvizo

Open Access Theses & Dissertations

Like most developing nations, Indonesia is at a crucial stage in its modern political and economic history. Opposing forces are constantly at work, a government struggling to make Indonesia a modern nation and the economic demands of a growing population. This presents the country with a multitude of problems. One of several is that nature's resources are exploited for personal economic gain with no regard for the long-term effects. This is a major concern for environmental conservation and non-profit government organizations (NGOs) worldwide. The American NGO Rare is at the forefront of this issue. Its aim is to meet community …

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Pwisegen: A Genetic Algorithms-Based Framework For Pairwise Test Set Generation, Pedro Flores Jan 2010

Pwisegen: A Genetic Algorithms-Based Framework For Pairwise Test Set Generation, Pedro Flores

Open Access Theses & Dissertations

Pairwise testing is a combinatorial testing approach that can be used to reduce the number of test cases dramatically for a software system. It specializes in the type of testing where the outcome of a system depends on the combination of several input parameters. This technique is widely used when there is not enough time to try out all possible combinations of the input parameters involved, because that would be very time consuming. The purpose of pairwise testing technique is to avoid testing all possible value combinations that a system can receive, and to preferably take a representative sample of …

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