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2006

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Articles 1711 - 1740 of 5872

Full-Text Articles in Physical Sciences and Mathematics

Ceg 720-01: Computer Architecture, Jack Jean Jul 2006

Ceg 720-01: Computer Architecture, Jack Jean

Computer Science & Engineering Syllabi

No abstract provided.

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Geospatial Ontology Development And Semantic Analytics, I. Budak Arpinar, Cartic Ramakrishnan, Molly Azami, Amit P. Sheth, E. Lynn Usery, Mei-Po Kwan Jul 2006

Geospatial Ontology Development And Semantic Analytics, I. Budak Arpinar, Cartic Ramakrishnan, Molly Azami, Amit P. Sheth, E. Lynn Usery, Mei-Po Kwan

Kno.e.sis Publications

Geospatial ontology development and semantic knowledge discovery addresses the need for modeling, analyzing and visualizing multimodal information, and is unique in offering integrated analytics that encompasses spatial, temporal and thematic dimensions of information and knowledge. The comprehensive ability to provide integrated analysis from multiple forms of information and use of explicit knowledge make this approach unique. This also involves specification of spatiotemporal thematic ontologies and populating such ontologies with high quality knowledge. Such ontologies form the basis for defining the meaning of important relations terms, such as near or surrounded by, and enable computation of spatiotemporal thematic proximity measures we …

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Optimal Adaptation Of Web Processes With Inter-Service Dependencies, Kunal Verma, Prashant Doshi, Karthik Gomadam, John A. Miller, Amit P. Sheth Jul 2006

Optimal Adaptation Of Web Processes With Inter-Service Dependencies, Kunal Verma, Prashant Doshi, Karthik Gomadam, John A. Miller, Amit P. Sheth

Kno.e.sis Publications

We present methods for optimally adapting Web processes to exogenous events while preserving inter-service dependencies. For example, in a supply chain process, orders placed by the manufacturer may get delayed in arriving. In response to this event, the manufacturer has the choice of either waiting out the delay or changing the supplier. Additionally, there may be compatibility constraints between the different orders, thereby introducing the problem of coordination between them if the manufacturer chooses to change the suppliers. We present our methods within the framework of autonomic Web processes. This framework seeks to add properties of self-configuration, adaptation, and self-optimization …

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Nitrogen Fixation And Release Of Fixed Nitrogen By Trichodesmium Spp. In The Gulf Of Mexico, Margaret R. Mulholland, Peter W. Bernhardt, Cynthia A. Heil, Deborah A. Bronk, Judith M. O'Neil Jul 2006

Nitrogen Fixation And Release Of Fixed Nitrogen By Trichodesmium Spp. In The Gulf Of Mexico, Margaret R. Mulholland, Peter W. Bernhardt, Cynthia A. Heil, Deborah A. Bronk, Judith M. O'Neil

VIMS Articles

During a 3‐yr study in the Gulf of Mexico, we measured dinitrogen (N2) fixation and nitrogen (N) release by Trichodesmium and compared these rates with water column N demand and the estimated N necessary to support blooms of Karenia brevis, a toxic dinoflagellate that severely affects the West Florida shelf. Net and gross N2 fixation rates were compared in simultaneous incubations using δ15N2 uptake and acetylene reduction, respectively. The difference between net and gross N2 fixation is assumed to be an approximation of the rate of N release. Results demonstrate that Trichodesmium in the Gulf of Mexico are fixing …

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Three-Terminal Devices To Examine Single Molecule Conductance Switching, Z K. Keane, Jacob W. Ciszek, J M. Tour, D Natelson Jul 2006

Three-Terminal Devices To Examine Single Molecule Conductance Switching, Z K. Keane, Jacob W. Ciszek, J M. Tour, D Natelson

Chemistry: Faculty Publications and Other Works

We report electronic transport measurements of single-molecule transistor devices incorporating bipyridyl-dinitro oligophenylene-ethynylene dithiol (BPDN-DT), a molecule known to exhibit conductance switching in other measurement configurations. We observe hysteretic conductance switching in 8% of devices with measurable currents, and find that dependence of the switching properties on gate voltage is rare when compared to other single-molecule transistor devices. This suggests that polaron formation is unlikely to be responsible for switching in these devices. We discuss this and alternative switching mechanisms.

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The Role Of The Hpa Axis In Psychiatric Disorders And Crf Antagonists As Potential Treatments, Paul A. Keller, A. Mccluskey, J. Morgan, S. M. O'Connor Jul 2006

The Role Of The Hpa Axis In Psychiatric Disorders And Crf Antagonists As Potential Treatments, Paul A. Keller, A. Mccluskey, J. Morgan, S. M. O'Connor

Faculty of Science - Papers (Archive)

An overview of the links between the Hypothalamic-Pituitary-Adrenal (HPA) axis and psychiatric disorders is presented. The current treatments are outlined, indicating that they are insufficient to meet the needs of those that suffer from these affective disorders. Therefore, there is an urgent need for the generation of new therapeutics, in particular, against new targets. The association of the corticotrophin releasing factor (CRF) and the HPA axis indicates that CRF antagonists should be beneficial as potential therapeutics.

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Reactions Of Iminoglycines With C60 Fullerene And Their Unambiguous Characterisation Using Nmr Spectroscopy, Paul A. Keller, Stephen G. Pyne, Bill C. Hawkins Jul 2006

Reactions Of Iminoglycines With C60 Fullerene And Their Unambiguous Characterisation Using Nmr Spectroscopy, Paul A. Keller, Stephen G. Pyne, Bill C. Hawkins

Faculty of Science - Papers (Archive)

This review examines the addition of iminoglycine derivatives to C60, yielding protected fullerenyl pyrroline derivatives. Subsequent reduction with sodium cyanoborohydride produces ring-opening adducts which are protected fullerenyl α-amino acids. Pyrroline bisadducts can be produced using tethers to link two iminoglycine units together, and variations include combining with malonate reactive groups this giving rise to interesting observations as to the regioselectivity of such reactions. All derivatives are fully characterised by NMR spectroscopy, and in the case of bis-adducts, the regioselectivity is determined from 1H/13C and 13C/13C connectivity patterns using HMBC and INADEQUATE experiments, respectively, thus eliminating the need for comparative techniques …

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Climate Change Manipulations Show Antarctic Flora Is More Strongly Affected By Elevated Nutrients Than Water, J. Wasley, Sharon A. Robinson, C. E. Lovelock, M. Popp Jul 2006

Climate Change Manipulations Show Antarctic Flora Is More Strongly Affected By Elevated Nutrients Than Water, J. Wasley, Sharon A. Robinson, C. E. Lovelock, M. Popp

Faculty of Science - Papers (Archive)

Climate change is expected to affect the high latitudes first and most severely, rendering Antarctica one of the most significant baseline environments for the study of global climate change. The indirect effects of climate warming, including changes to the availability of key environmental resources, such as water and nutrients, are likely to have a greater impact upon continental Antarctic terrestrial ecosystems than the effects of fluctuations in temperature alone. To investigate the likely impacts of a wetter climate on Antarctic terrestrial communities a multi-season, manipulative field experiment was conducted in the floristically important Windmill Islands region of East Antarctica. Four …

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Status Of The Major Oyster Diseases In Virginia 2005 A Summary Of The Annual Monitoring Program, Ryan Carnegie, Eugene M. Burreson Jul 2006

Status Of The Major Oyster Diseases In Virginia 2005 A Summary Of The Annual Monitoring Program, Ryan Carnegie, Eugene M. Burreson

Reports

More normal riverflows and salinities returned in 2005 after two very wet years. Temperatures were somewhat colder than normal during the winter, and warmer during the summer. The physical environment was generally more favorable for parasite activity, and thus brought a slight increase in prevalence and intensity of the oyster diseases caused by Perkinsus marinus (Dermo) and Haplosporidium nelsoni (MSX). Among quarterly James River Survey sites, maximum annual P. marinus prevalences returned to levels typical of the mid- 1990s, before the years of drought. P. marinus prevalence reached 92% at Wreck Shoal, 56% at Point of Shoal, 68% at Horsehead …

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A Survey Of The Effectiveness Of Existing Marsh Toe Protection Structures In Virginia, Karen Duhring, Thomas A. Barnard, Center For Coastal Resources Managment, C. Scott Hardaway Jr., Shoreline Studies Program Jul 2006

A Survey Of The Effectiveness Of Existing Marsh Toe Protection Structures In Virginia, Karen Duhring, Thomas A. Barnard, Center For Coastal Resources Managment, C. Scott Hardaway Jr., Shoreline Studies Program

Reports

Using tidal marshes and other vegetated treatments for upland erosion control has been an accepted practice for years, yet the scientific understanding and established guidelines for this approach are limited. This survey was conducted to evaluate the efficacy of existing marsh toe protection structures, a particular type of erosion control treatment associated with tidal marshes on Chesapeake Bay shorelines. Field evaluations were conducted at 36 sites in 6 localities on the Middle Peninsula and Northern Neck of Virginia. General dimensions of each structure were recorded and observations made of erosion evidence, structural integrity, construction access impacts, and adjacent landscape settings. …

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Numbers And Polynomials- 50 Years Since The Publication Of Wittgenstein's Bemerkungen Über Die Grundlagen Der Mathematik (1956): Mathematical And Educational Reflections, Giorgio T. Bagni Jul 2006

Numbers And Polynomials- 50 Years Since The Publication Of Wittgenstein's Bemerkungen Über Die Grundlagen Der Mathematik (1956): Mathematical And Educational Reflections, Giorgio T. Bagni

The Mathematics Enthusiast

According to L. Wittgenstein, the meaning of a mathematical object is to be grounded upon its use. In this paper we consider Robinson theory Q, the subtheory of firstorder Peano Arithmetic PA; some theorems and conjectures can be interpreted over one model of Q given by a universe of polynomials; with respect to nonconstant polynomials some proofs by elementary methods are given and compared with corresponding results in the standard model of PA. We conclude that the creative power of the language can be pointed out in how the language itself is embedded into the rest of human activities, and …

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The Effects Of Blended E-Learning On Mathematics And Computer Attitudes In Pre-Calculus Algebra, Balarabe Yushau Jul 2006

The Effects Of Blended E-Learning On Mathematics And Computer Attitudes In Pre-Calculus Algebra, Balarabe Yushau

The Mathematics Enthusiast

This study examines the influence of blended e-learning on students' attitude towards mathematics and computers. A random sample of 70 students of the preparatory year program of King Fahd University of Petroleum & Minerals (KFUPM), Dhahran served as the sample of this study. Data were collected at the beginning (pre-program) and the end (post-program) of the semester using Aiken Mathematics Attitude Scale and Greessen and Loyd Computer Attitude Scale. The result indicates that the subjects have positive attitude towards mathematics and computer. However, analysis of variance shows no statistically significant change in students’ attitudes towards mathematics and computer except for …

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An In-Depth Investigation Of The Divine Ratio, Birch Fett Jul 2006

An In-Depth Investigation Of The Divine Ratio, Birch Fett

The Mathematics Enthusiast

The interesting thing about mathematical concepts is that we can trace their development or discoveries throughout history. Most cultures of the ancient world had some form of mathematics, and these basic skills developed into what we now call modern mathematics. The divine ratio is similar in that it was used in many different sections of history. The divine ratio, sometimes called the golden ratio or golden section, has been found in very diverse areas. The mathematical concepts of the golden ration have been found throughout nature, in architecture, music as well as in art. Phi is an astonishing number because …

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Frames Of Reference And Achievement In Elementary Arithmetic, Eddie M. Gray, Demetra Pitta-Pantazi Jul 2006

Frames Of Reference And Achievement In Elementary Arithmetic, Eddie M. Gray, Demetra Pitta-Pantazi

The Mathematics Enthusiast

This paper considers the relationship between 8-11 years old students’ numerical achievement and a possible disposition towards the construction of particular frames of reference. The paper uses the characteristics of a variety of kinds of images to focus upon frames of reference and explores a possible relationship between children’s verbal descriptions of concrete and abstract nouns and the different ways they respond to aspects of elementary arithmetic. It seeks to establish whether or not children towards the extremes of arithmetical achievement (low and high achievement) have a disposition towards different kinds of frames of reference. The analysis suggests that at …

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Tme's Worldwide Circulation Statistics Jul 2006

Tme's Worldwide Circulation Statistics

The Mathematics Enthusiast

No abstract provided.

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Implementation Of Microsoft's Virtual Pc In Networking Curriculum, Jim Yulga Jul 2006

Implementation Of Microsoft's Virtual Pc In Networking Curriculum, Jim Yulga

Regis University Student Publications (comprehensive collection)

Using Microsoft's Virtual PC software product as a virtual technology in the implementation of Network Specialist curriculum allows increased versatility and considerable hardware cost savings. Rather than purchasing individual computers or removable hard drives, using boot manager programs, or simulation software (including Computer Based Training programs), for student use in learning the administration of an operating system, one computer with hard drive, sufficient processor power, and RAM can be used to implement the effective hands-on learning approach of plan, implement and test, and then review. In addition, this software allows a non-dedicated (production) computer lab to be used. This is …

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Relationships Between Pacific And Atlantic Ocean Sea Surface Temperatures And U.S. Streamflow Variability, Glenn A. Tootle, Thomas C. Piechota Jul 2006

Relationships Between Pacific And Atlantic Ocean Sea Surface Temperatures And U.S. Streamflow Variability, Glenn A. Tootle, Thomas C. Piechota

Civil and Environmental Engineering and Construction Faculty Research

An evaluation of Pacific and Atlantic Ocean sea surface temperatures (SSTs) and continental U.S. streamflow was performed to identify coupled regions of SST and continental U.S. streamflow variability. Both SSTs and streamflow displayed temporal variability when applying the singular value decomposition (SVD) statistical method. Initially, an extended temporal evaluation was performed using the entire period of record (i.e., all years from 1951 to 2002). This was followed by an interdecadal-temporal evaluation for the Pacific (Atlantic) Ocean based on the phase of the Pacific Decadal Oscillation (PDO) (Atlantic Multidecadal Oscillation (AMO)). Finally, an extended temporal evaluation was performed using detrended SST …

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Numerical Simulation And Graphical Analysis Of In Vitro Benign Tumor Growth: Application Of Single-Particle State Bosonic Matter Equation With Length Scaling, Pradip K. Biswas, Jiansen Niu, Tobias Frederico, Valentin Gogonea Jul 2006

Numerical Simulation And Graphical Analysis Of In Vitro Benign Tumor Growth: Application Of Single-Particle State Bosonic Matter Equation With Length Scaling, Pradip K. Biswas, Jiansen Niu, Tobias Frederico, Valentin Gogonea

Chemistry Faculty Publications

We describe the application of a non-linear single-particle state bosonic condensate equation to simulate multicellular tumor growth by treating it as a coupling of two classical wave equations with real components. With one component representing the amplitude of the cells in their volume growth phase and the other representing the amplitude of the cells in their proliferation or mitosis phase, the two components of the coupled equation feed each other during the time evolution and are coupled together through diffusion and other linear and non-linear terms. The features of quiescent and necrotic cells, which result from poor nutrient diffusion into …

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Decreasing Emissions Of Methane From Rice Agriculture, M. A. K. Khalil, Martha J. Shearer Jul 2006

Decreasing Emissions Of Methane From Rice Agriculture, M. A. K. Khalil, Martha J. Shearer

Environmental Science and Management Faculty Publications and Presentations

Methane emissions from rice fields are controlled by several key factors. The most important are the application of organic soil amendments and water management: whether the fields are flooded intermittently or continuously. The total annual emissions from any country or the world are thus affected by the area of rice harvested, and a composite emission factor that takes into account how the various agricultural practices are distributed in terms of fertilizer use and water management, as well as other less important variables. Over decades the area of rice harvested changes but so does the composite emission factor. The product therefore, …

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Solar Cycle Variations In The Composition Of The Suprathermal Heavy-Ion Population Near 1 Au, Mihir I. Desai, Glenn M. Mason, Joseph E. Mazur, Joseph R. Dwyer Jul 2006

Solar Cycle Variations In The Composition Of The Suprathermal Heavy-Ion Population Near 1 Au, Mihir I. Desai, Glenn M. Mason, Joseph E. Mazur, Joseph R. Dwyer

Aerospace, Physics, and Space Science Faculty Publications

We have measured the annual variation in the quiet-time composition of interplanetary suprathermal ions between 0.04 and 1 MeV nucleon-1 from 1994 November 20 through 2006 January 1. Our results show the following: (1) The C/O and Fe/O ratios are similar to the corresponding values measured in the solar wind and corotating interaction regions (CIRs) during solar minimum conditions of 1994-1997 and 2005. (2) During periods of increased solar activity between 1998 and 2002, the C/O ratio is similar to that measured in solar energetic particle (SEP) events, while the Fe/O ratio lies between the values measured in coronal mass …

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Description Of Light Focusing By A Lens Using Vector Diffraction Theory, Shekhar Gaha, Glen D. Gillen Jul 2006

Description Of Light Focusing By A Lens Using Vector Diffraction Theory, Shekhar Gaha, Glen D. Gillen

Physics

For a plane wave incident on a spherical lens at normal incidence, the field distributions in the focal region are calculated using vector diffraction theory showing the effects of aberration.

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Dissolution, Reactor, And Environmental Behavior Of Zro 2 -Mgo Inert Fuel Matrix Neutronic Evaluation Of Mgo-Zro2 Inert Fuels, E. Fridman, A. Galperin, E. Shwageraus Jul 2006

Dissolution, Reactor, And Environmental Behavior Of Zro 2 -Mgo Inert Fuel Matrix Neutronic Evaluation Of Mgo-Zro2 Inert Fuels, E. Fridman, A. Galperin, E. Shwageraus

Fuels Campaign (TRP)

In the second year of the “Dissolution, Reactor, and Environmental Behavior of ZrO2-MgO Inert Fuel Matrix” project initiated and directed by UNLV, the Ben-Gurion University (BGU) group research was focused on the development of practical PWR core nuclear design fully loaded with Reactor Grade (RG) Pu fuel incorporated in fertile free matrix. The design strategy was based on the basic feasibility study results performed at BGU in the Year 1 of the project.

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Unlv Magazine, Carol C. Harter, Karen Sharp, Gian Galassi, Tony Allen, Jennifer Lawson, Shane Bevell, Lori Bachand, Regina Vaccari, Pete Codella, Cate Weeks, Erin O'Donnell, Diane Russell, Phil Hagen Jul 2006

Unlv Magazine, Carol C. Harter, Karen Sharp, Gian Galassi, Tony Allen, Jennifer Lawson, Shane Bevell, Lori Bachand, Regina Vaccari, Pete Codella, Cate Weeks, Erin O'Donnell, Diane Russell, Phil Hagen

UNLV Magazine

No abstract provided.

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A Classification Of Strategies Employed By High School Students In Isomorphic Combinatorial Problems, Martina Janácková, Jaroslav Janácek Jul 2006

A Classification Of Strategies Employed By High School Students In Isomorphic Combinatorial Problems, Martina Janácková, Jaroslav Janácek

The Mathematics Enthusiast

The aim of the paper is to discuss some aspects of the combinatorial thinking of high school students. We took one student - Jane and gave her 4 isomorphic testing problems. Then we tried to classify the different strategies the students took in their solutions.

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Using Manipulatives In Mathematical Problem Solving: A Performance-Based Analysis, Catherine A. Kelly Jul 2006

Using Manipulatives In Mathematical Problem Solving: A Performance-Based Analysis, Catherine A. Kelly

The Mathematics Enthusiast

This article explores problem solving in elementary classrooms while focusing on how children use (perform tasks) manipulatives and/or tools in problem solving while working on mathematical tasks. Ways for teachers to assess children’s learning through performance-based tool (manipulative) use will also be examined and suggested. Current research reveals that teachers need to teach and assess children’s mathematical knowledge in ways that will allow them to show (perform) what they really understand. And, teachers must be able to see beyond obvious correct or incorrect answers into children’s thinking processes by testing with “tests that allow students the opportunity to show what …

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Geomorphic Impact And Rapid Subsequent Recovery From The 1996 Skeióarársandur Jökulhlaup, Iceland, Measured With Multi-Year Airborne Lidar, Laurence C. Smith, Yongwei Sheng, Francis J. Magilligan, Norman D. Smith, Basil Gomez, Leal A. K. Mertes, William B. Krabill, James B. Garvin Jul 2006

Geomorphic Impact And Rapid Subsequent Recovery From The 1996 Skeióarársandur Jökulhlaup, Iceland, Measured With Multi-Year Airborne Lidar, Laurence C. Smith, Yongwei Sheng, Francis J. Magilligan, Norman D. Smith, Basil Gomez, Leal A. K. Mertes, William B. Krabill, James B. Garvin

Department of Earth and Atmospheric Sciences: Faculty Publications

The November 1996 jökulhlaup that burst from the Vatnajökull ice cap onto Skeiðarársandur was the highest-magnitude flood ever measured on the largest active glacial outwash plain (sandur). Centimeter-scale elevation transects, measured from repeat-pass airborne laser altimetry missions flown in 1996 (pre-flood), 1997, and 2001, show that sediment deposition exceeded erosion across the central Skeiðarársandur and established an average net elevation gain of +22 cm for the event. Net elevation gains of +29 and +24 cm occurred in braided channels of the Gígjukvísl and Skeiðará rivers, respectively. Nearly half of these gains, however, were removed within 4 years, and the two …

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Learning A Rendezvous Task With Dynamic Joint Action Perception, Nancy Fulda, Dan A. Ventura Jul 2006

Learning A Rendezvous Task With Dynamic Joint Action Perception, Nancy Fulda, Dan A. Ventura

Faculty Publications

Groups of reinforcement learning agents interacting in a common environment often fail to learn optimal behaviors. Poor performance is particularly common in environments where agents must coordinate with each other to receive rewards and where failed coordination attempts are penalized. This paper studies the effectiveness of the Dynamic Joint Action Perception (DJAP) algorithm on a grid-world rendezvous task with this characteristic. The effects of learning rate, exploration strategy, and training time on algorithm effectiveness are discussed. An analysis of the types of tasks for which DJAP learning is appropriate is also presented.

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Preparing More Effective Liquid State Machines Using Hebbian Learning, David Norton, Dan A. Ventura Jul 2006

Preparing More Effective Liquid State Machines Using Hebbian Learning, David Norton, Dan A. Ventura

Faculty Publications

In Liquid State Machines, separation is a critical attribute of the liquid—which is traditionally not trained. The effects of using Hebbian learning in the liquid to improve separation are investigated in this paper. When presented with random input, Hebbian learning does not dramatically change separation. However, Hebbian learning does improve separation when presented with real-world speech data.

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Editorial: A Global Intellectual Collage, Bharath Sriraman Jul 2006

Editorial: A Global Intellectual Collage, Bharath Sriraman

The Mathematics Enthusiast

No abstract provided.

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The Synthesis Of Zinc Oxide By Direct And Indirect Methods, Grainne Duffy Jul 2006

The Synthesis Of Zinc Oxide By Direct And Indirect Methods, Grainne Duffy

Masters

The synthesis of zinc oxide through three routes was investigated; carboxylic acid chelation, polymer assisted synthesis in an alcoholic medium and slow thermolysis of precursor. In the case of carboxylic acid chelation, it was determined that the rate at which the precursor is formed has a significant effect on the quality of zinc oxide particles produced. Investigation of the effect of concentration, pH and species of chelating agent used on the purity and structure of product was undertaken. Examination of the composition and morphology of materials produced revealed the presence of single-crystalline spheres, the packing density and aggregation morphology of …

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